1
|
Novel paradigm enables accurate monthly gestational screening to prevent congenital toxoplasmosis and more. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.04.26.23289132. [PMID: 37162985 PMCID: PMC10168490 DOI: 10.1101/2023.04.26.23289132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Background Congenital toxoplasmosis is a treatable, preventable disease, but untreated causes death, prematurity, loss of sight, cognition and motor function, and substantial costs worldwide. Methods/Findings In our ongoing USA feasibility/efficacy clinical trial, data collated with other ongoing and earlier published results proved high performance of an Immunochromatographic-test(ICT) that enables accurate, rapid diagnosis/treatment, establishing new paradigms for care. Overall results from patient blood and/or serum samples tested with ICT compared with gold-standard-predicate-test results found ICT performance for 4606 sera/1876 blood, 99.3%/97.5% sensitive and 98.9%/99.7% specific. However, in the clinical trial the FDA-cleared-predicate test initially caused practical, costly problems due to false-positive-IgM results. For 58 persons, 3/43 seronegative and 2/15 chronically infected persons had false positive IgM predicate tests. This caused substantial anxiety, concerns, and required costly, delayed confirmation in reference centers. Absence of false positive ICT results contributes to solutions: Lyon and Paris France and USA Reference laboratories frequently receive sera with erroneously positive local laboratory IgM results impeding patient care. Therefore, thirty-two such sera referred to Lyon's Reference laboratory were ICT-tested. We collated these with other earlier/ongoing results: 132 of 137 USA or French persons had false positive local laboratory IgM results identified correctly as negative by ICT. Five false positive ICT results in Tunisia and Marseille, France, emphasize need to confirm positive ICT results with Sabin-Feldman-Dye-test or western blot. Separate studies demonstrated high performance in detecting acute infections, meeting FDA, CLIA, WHO ASSURED, CEMark criteria and patient and physician satisfaction with monthly-gestational-ICT-screening. Conclusions/Significance This novel paradigm using ICT identifies likely false positives or raises suspicion that a result is truly positive, rapidly needing prompt follow up and treatment. Thus, ICT enables well-accepted gestational screening programs that facilitate rapid treatment saving lives, sight, cognition and motor function. This reduces anxiety, delays, work, and cost at point-of-care and clinical laboratories. Author’s Summary Toxoplasmosis is a major health burden for developed and developing countries, causing damage to eyes and brain, loss of life and substantial societal costs. Prompt diagnosis in gestational screening programs enables treatment, thereby relieving suffering, and leading to > 14-fold cost savings for care. Herein, we demonstrate that using an ICT that meets WHO ASSURED-criteria identifying persons with/without antibody to Toxoplasma gondii in sera and whole blood with high sensitivity and specificity, is feasible to use in USA clinical practice. We find this new approach can help to obviate the problem of detection of false positive anti- T.gondii IgM results for those without IgG antibodies to T.gondii when this occurs in present, standard of care, predicate USA FDA cleared available assays. Thus, this accurate test facilitates gestational screening programs and a global initiative to diagnose and thereby prevent and treat T.gondii infection. This minimizes likelihood of false positives (IgG and/or IgM) while maintaining maximum sensitivity. When isolated IgM antibodies are detected, it is necessary to confirm and when indicated continue follow up testing in ∼2 weeks to establish seroconversion. Presence of a positive ICT makes it likely that IgM is truly positive and a negative ICT makes it likely that IgM will be a false positive without infection. These results create a new, enthusiastically-accepted, precise paradigm for rapid diagnosis and validation of results with a second-line test. This helps eliminate alarm and anxiety about false-positive results, while expediting needed treatment for true positive results and providing back up distinguishing false positive tests.
Collapse
|
2
|
2021 Canadian Surgery Forum01. Design and validation of a unique endoscopy simulator using a commercial video game03. Is ethnicity an appropriate measure of health care marginalization?: A systematic review and meta-analysis of the outcomes of diabetic foot ulceration in the Aboriginal population04. Racial disparities in surgery — a cross-specialty matched comparison between black and white patients05. Starting late does not increase the risk of postoperative complications in patients undergoing common general surgical procedures06. Ethical decision-making during a health care crisis: a resource allocation framework and tool07. Ensuring stability in surgical training program leadership: a survey of program directors08. Introducing oncoplastic breast surgery in a community hospital09. Leadership development programs for surgical residents: a review of the literature10. Superiority of non-opioid postoperative pain management after thyroid and parathyroid operations: a systematic review and meta-analysis11. Timing of ERCP relative to cholecystectomy in patients with ductal gallstone disease12. A systematic review and meta-analysis of randomized controlled trials comparing intraoperative red blood cell transfusion strategies13. Postoperative outcomes after frail elderly preoperative assessment clinic: a single-institution Canadian perspective14. Selective opioid antagonists following bowel resection for prevention of postoperative ileus: a systematic review and meta-analysis15. Peer-to-peer coaching after bile duct injury16. Laparoscopic median arcuate ligament release: a video abstract17. Retroperitoneoscopic approach to adrenalectomy19. Endoscopic Zenker diverticulotomy: a video abstract20. Variability in surgeons’ perioperative management of pheochromocytomas in Canada21. The contribution of surgeon and hospital variation in transfusion practice to outcomes for patients undergoing elective gastrointestinal cancer surgery: a population-based analysis22. Perioperative transfusions for gastroesophageal cancers: risk factors and short- and long-term outcomes23. The association between frailty and time alive and at home after cancer surgery among older adults: a population-based analysis24. Psychological and workplace-related effects of providing surgical care during the COVID-19 pandemic in British Columbia, Canada25. Safety of venous thromboembolism prophylaxis in endoscopic retrograde cholangiopancreatography: a systematic review26. Complications and reintervention following laparoscopic subtotal cholecystectomy: a systematic review and meta-analysis27. Synchronization of pupil dilations correlates with team performance in a simulated laparoscopic team coordination task28. Receptivity to and desired design features of a surgical peer coaching program: an international survey9. Impact of the COVID-19 pandemic on rates of emergency department utilization due to general surgery conditions30. The impact of the current COVID-19 pandemic on the exposure of general surgery trainees to operative procedures31. Association between academic degrees and research productivity: an assessment of academic general surgeons in Canada32. Laparoscopic endoscopic cooperative surgery (LECS) for subepithelial gastric lesion: a video presentation33. Effect of the COVID-19 pandemic on acute care general surgery at an academic Canadian centre34. Opioid-free analgesia after outpatient general surgery: a pilot randomized controlled trial35. Impact of neoadjuvant immunotherapy or targeted therapies on surgical resection in patients with solid tumours: a systematic review and meta-analysis37. Surgical data recording in the operating room: a systematic review of modalities and metrics38. Association between nonaccidental trauma and neighbourhood socioeconomic status during the COVID-19 pandemic: a retrospective analysis39. Laparoscopic repair of a transdiaphragmatic gastropleural fistula40. Video-based interviewing in medicine: a scoping review41. Indocyanine green fluorescence angiography for prevention of anastomotic leakage in colorectal surgery: a cost analysis from the hospital payer’s perspective43. Perception or reality: surgical resident and faculty assessments of resident workload compared with objective data45. When illness and loss hit close to home: Do health care providers learn how to cope?46. Remote video-based suturing education with smartphones (REVISE): a randomized controlled trial47. The evolving use of robotic surgery: a population-based analysis48. Prophylactic retromuscular mesh placement for parastomal hernia prevention: a retrospective cohort study of permanent colostomies and ileostomies49. Intracorporeal versus extracorporeal anastomosis in laparoscopic right hemicolectomy: a retrospective cohort study on anastomotic complications50. A lay of the land — a description of Canadian academic acute care surgery models51. Emergency general surgery in Ontario: interhospital variability in structures, processes and models of care52. Trauma 101: a virtual case-based trauma conference as an adjunct to medical education53. Assessment of the National Surgical Quality Improvement Program Surgical Risk Calculator for predicting patient-centred outcomes of emergency general surgery patients in a Canadian health care system54. Sustainability of a narcotic reduction initiative: 1 year following the Standardization of Outpatient Procedure (STOP) Narcotics Study55. Barriers to transanal endoscopic microsurgery referral56. Geospatial analysis of severely injured rural patients in a geographically complex landscape57. Implementation of an incentive spirometry protocol in a trauma ward: a single-centre pilot study58. Impostor phenomenon is a significant risk factor for burnout and anxiety in Canadian resident physicians: a cross-sectional survey59. Understanding the influence of perioperative education on performance among surgical trainees: a single-centre experience60. The effect of COVID-19 pandemic on current and future endoscopic personal protective equipment practices: a national survey of 77 endoscopists61. Case report: delayed presentation of perforated sigmoid diverticulitis as necrotizing infection of the lower limb62. Investigating disparities in surgical outcomes in Canadian Indigenous populations63. Fundoplication is superior to medical therapy for Barrett esophagus disease regression and progression: a systematic review and meta-analysis64. Development of a novel online general surgery learning platform and a qualitative preimplementation analysis65. Hagfish slime exudate as a potential novel hemostatic agent: developing a standardized assessment protocol66. The effect of the first wave of the COVID-19 pandemic on surgical oncology case volumes and wait times67. Safety of same-day discharge in high-risk patients undergoing ambulatory general surgery68. External validation of the Codman score in colorectal surgery: a pragmatic tool to drive quality improvement69. Improved morbidity and gastrointestinal restoration rates without compromising survival rates for diverting loop ileostomy with colonic lavage versus total abdominal colectomy for fulminant Clostridioides difficile colitis: a multicentre retrospective cohort study70. Potential access to emergency general surgical care in Ontario71. Immersive virtual reality (iVR) improves procedural duration, task completion and accuracy in surgical trainees: a systematic review01. Clinical validation of the Canada Lymph Node Score for endobronchial ultrasound02. Venous thromboembolism in surgically treated esophageal cancer patients: a provincial population-based study03. Venous thromboembolism in surgically treated lung cancer patients: a population-based study04. Is frailty associated with failure to rescue after esophagectomy? A multi-institutional comparative analysis of outcomes05. Routine systematic sampling versus targeted sampling of lymph nodes during endobronchial ultrasound: a feasibility randomized controlled trial06. Gastric ischemic conditioning reduces anastomotic complications in patients undergoing esophagectomy: a systematic review and meta-analysis07. Move For Surgery, a novel preconditioning program to optimize health before thoracic surgery: a randomized controlled trial08. In case of emergency, go to your nearest emergency department — Or maybe not?09. Does preoperative SABR increase the risk of complications from lung cancer resection? A secondary analysis of the MISSILE trial10. Segmental resection for lung cancer: the added value of near-infrared fluorescence mapping diminishes with surgeon experience11. Toward competency-based continuing professional development for practising surgeons12. Stereotactic body radiotherapy versus surgery in older adults with NSCLC — a population-based, matched analysis of long-term dependency outcomes13. Role of adjuvant therapy in esophageal cancer patients after neoadjuvant therapy and curative esophagectomy: a systematic review and meta-analysis14. Evaluation of population characteristics on the incidence of thoracic empyema: an ecological study15. Determining the optimal stiffness colour threshold and stiffness area ratio cut-off for mediastinal lymph node staging using EBUS elastography and AI: a pilot study16. Quality assurance on the use of sequential compression stockings in thoracic surgery (QUESTs)17. The relationship between fissureless technique and prolonged air leak for patients undergoing video-assisted thoracoscopic lobectomy18. CXCR2 inhibition as a candidate for immunomodulation in the treatment of K-RAS-driven lung adenocarcinoma19. Assessment tools for evaluating competency in video-assisted thoracoscopic lobectomy: a systematic review20. Understanding the current practice on chest tube management following lung resection among thoracic surgeons across Canada21. Effect of routine jejunostomy tube insertion in esophagectomy: a systematic review and meta-analysis22. Recurrence of primary spontaneous pneumothorax following bullectomy with pleurodesis or pleurectomy: a retrospective analysis23. Surgical outcomes following chest wall resection and reconstruction24. Outcomes following surgical management of primary mediastinal nonseminomatous germ cell tumours25. Does robotic approach offer better nodal staging than thoracoscopic approach in anatomical resection for non–small cell lung cancer? A single-centre propensity matching analysis26. Competency assessment for mediastinal mass resection and thymectomy: design and Delphi process27. The contemporary significance of venous thromboembolism (deep venous thrombosis [DVT] and pulmonary embolus [PE]) in patients undergoing esophagectomy: a prospective, multicentre cohort study to evaluate the incidence and clinical outcomes of VTE after major esophageal resections28. Esophageal cancer: symptom severity at the end of life29. The impact of pulmonary artery reconstruction on postoperative and oncologic outcomes: a systematic review30. Association with surgical technique and recurrence after laparoscopic repair of paraesophageal hernia: a single-centre experience31. Enhanced recovery after surgery (ERAS) in esophagectomy32. Surgical treatment of esophageal cancer: trends in surgical approach and early mortality at a single institution over the past 18 years34. Adverse events and length of stay following minimally invasive surgery in paraesophageal hernia repair35. Long-term symptom control comparison of Dor and Nissen fundoplication following laparoscopic para-esophageal hernia repair: a retrospective analysis36. Willingness to pay: a survey of Canadian patients’ willingness to contribute to the cost of robotic thoracic surgery37. Radiomics in early-stage lung adenocarcinoma: a prediction tool for tumour immune microenvironments38. Effectiveness of intraoperative pyloric botox injection during esophagectomy: how often is endoscopic intervention required?39. An artificial intelligence algorithm for predicting lymph node malignancy during endobronchial ultrasound40. The effect of major and minor complications after lung surgery on length of stay and readmission41. Measuring cost of adverse events following thoracic surgery: a scoping review42. Laparoscopic paraesophageal hernia repair: characterization by hospital and surgeon volume and impact on outcomes43. NSQIP 5-Factor Modified Frailty Index predicts morbidity but not mortality after esophagectomy44. Trajectory of perioperative HRQOL and association with postoperative complications in thoracic surgery patients45. Variation in treatment patterns and outcomes for resected esophageal cancer at designated thoracic surgery centres46. Patient-reported pretreatment health-related quality of life (HRQOL) predicts short-term survival in esophageal cancer patients47. Analgesic efficacy of surgeon-placed paravertebral catheters compared with thoracic epidural analgesia after Ivor Lewis esophagectomy: a retrospective noninferiority study48. Rapid return to normal oxygenation after lung surgery49. Examination of local and systemic inflammatory changes during lung surgery01. Implications of near-infrared imaging and indocyanine green on anastomotic leaks following colorectal surgery: a systematic review and meta-analysis02. Repeat preoperative endoscopy after regional implementation of electronic synoptic endoscopy reporting: a retrospective comparative study03. Consensus-derived quality indicators for operative reporting in transanal endoscopic surgery (TES)04. Colorectal lesion localization practices at endoscopy to facilitate surgical and endoscopic planning: recommendations from a national consensus Delphi process05. Black race is associated with increased mortality in colon cancer — a population-based and propensity-score matched analysis06. Improved survival in a cohort of patients 75 years and over with FIT-detected colorectal neoplasms07. Laparoscopic versus open loop ileostomy reversal: a systematic review and meta-analysis08. Posterior mesorectal thickness as a predictor of increased operative time in rectal cancer surgery: a retrospective cohort study09. Improvement of colonic anastomotic healing in mice with oral supplementation of oligosaccharides10. How can we better identify patients with rectal bleeding who are at high risk of colorectal cancer?11. Assessment of long-term bowel dysfunction in rectal cancer survivors: a population-based cohort study12. Observational versus antibiotic therapy for acute uncomplicated diverticulitis: a noninferiority meta-analysis based on a Delphi consensus13. Radiotherapy alone versus chemoradiotherapy for stage I anal squamous cell carcinoma: a systematic review and meta-analysis14. Is the Hartmann procedure for diverticulitis obsolete? National trends in colectomy for diverticulitis in the emergency setting from 1993 to 201515. Sugammadex in colorectal surgery: a systematic review and meta-analysis16. Sexuality and rectal cancer treatment: a qualitative study exploring patients’ information needs and expectations on sexual dysfunction after rectal cancer treatment17. Video-based interviews in selection process18. Impact of delaying colonoscopies during the COVID-19 pandemic on colorectal cancer detection and prevention19. Opioid use disorder associated with increased anastomotic leak and major complications after colorectal surgery20. Effectiveness of a rectal cancer education video on patient expectations21. Robotic-assisted rectosigmoid and rectal cancer resection: implementation and early experience at a Canadian tertiary centre22. An online educational app for rectal cancer survivors with low anterior resection syndrome: a pilot study23. The effects of surgeon specialization on the outcome of emergency colorectal surgery24. Outcomes after colorectal cancer resections in octogenarians and older in a regional New Zealand setting — What are the predictors of mortality?25. Long-term outcomes after seton placement for perianal fistulae with and without Crohn disease26. A survey of patient and surgeon preference for early ileostomy closure following restorative proctectomy for rectal cancer — Why aren’t we doing it?27. Crohn disease independently associated with longer hospital admission after surgery28. Short-stay (≤ 1 d) diverting loop ileostomy closure can be selectively implemented without an increase in readmission and complication rates: an ACS-NSQIP analysis29. A comparison of perineal stapled rectal prolapse resection and the Altemeier procedure at 2 Canadian academic hospitals30. Mental health and substance use disorders predict 90-day readmission and postoperative complications following rectal cancer surgery31. Early discharge after colorectal cancer resection: trends and impact on patient outcomes32. Oral antibiotics without mechanical bowel preparation prior to emergency colectomy reduces the risk of organ space surgical site infections: a NSQIP propensity score matched study33. The impact of robotic surgery on a tertiary care colorectal surgery program, an assessment of costs and short-term outcomes — a Canadian perspective34. Should we scope beyond the age limit of guidelines? Adenoma detection rates and outcomes of screening and surveillance colonoscopies in patients aged 75–79 years35. Emergency department admissions for uncomplicated diverticulitis: a nationwide study36. Obesity is associated with a complicated episode of acute diverticulitis: a nationwide study37. Green indocyanine angiography for low anterior resection in patients with rectal cancer: a prospective before-and-after study38. The impact of age on surgical recurrence of fibrostenotic ileocolic Crohn disease39. A qualitative study to explore the optimal timing and approach for the LARS discussion01. Racial, ethnic and socioeconomic disparities in diagnosis, treatment and survival of patients with breast cancer: a SEER-based population analysis02. First-line palliative chemotherapy for esophageal and gastric cancer: practice patterns and outcomes in the general population03. Frailty as a predictor for postoperative outcomes following pancreaticoduodenectomy04. Synoptic electronic operative reports identify practice variation in cancer surgery allowing for directed interventions to decrease variation05. The role of Hedgehog signalling in basal-like breast cancer07. Clinical and patient-reported outcomes in oncoplastic breast conservation surgery from a single surgeon’s practice in a busy community hospital in Canada08. Upgrade rate of atypical ductal hyperplasia: 10 years of experience and predictive factors09. Time to first adjuvant treatment after oncoplastic breast reduction10. Preparing to survive: improving outcomes for young women with breast cancer11. Opioid prescription and consumption in patients undergoing outpatient breast surgery — baseline data for a quality improvement initiative12. Rectal anastomosis and hyperthermic intraperitoneal chemotherapy: Should we avoid diverting loop ileostomy?13. Delays in operative management of early-stage, estrogen-receptor positive breast cancer during the COVID-19 pandemic — a multi-institutional matched historical cohort study14. Opioid prescribing practices in breast oncologic surgery15. Oncoplastic breast reduction (OBR) complications and patient-reported outcomes16. De-escalating breast cancer surgery: Should we apply quality indicators from other jurisdictions in Canada?17. The breast cancer patient experience of telemedicine during COVID-1918. A novel ex vivo human peritoneal model to investigate mechanisms of peritoneal metastasis in gastric adenocarcinoma (GCa)19. Preliminary uptake and outcomes utilizing the BREAST-Q patient-reported outcomes questionnaire in patients following breast cancer surgery20. Routine elastin staining improves detection of venous invasion and enhances prognostication in resected colorectal cancer21. Analysis of exhaled volatile organic compounds: a new frontier in colon cancer screening and surveillance22. A clinical pathway for radical cystectomy leads to a shorter hospital stay and decreases 30-day postoperative complications: a NSQIP analysis23. Fertility preservation in young breast cancer patients: a population-based study24. Investigating factors associated with postmastectomy unplanned emergency department visits: a population-based analysis25. Impact of patient, tumour and treatment factors on psychosocial outcomes after treatment in women with invasive breast cancer26. The relationship between breast and axillary pathologic complete response in women receiving neoadjuvant chemotherapy for breast cancer01. The association between bacterobilia and the risk of postoperative complications following pancreaticoduodenectomy02. Surgical outcome and quality of life following exercise-based prehabilitation for hepatobiliary surgery: a systematic review and meta-analysis03. Does intraoperative frozen section and revision of margins lead to improved survival in patients undergoing resection of perihilar cholangiocarcinoma? A systematic review and meta-analysis04. Prolonged kidney procurement time is associated with worse graft survival after transplantation05. Venous thromboembolism following hepatectomy for colorectal metastases: a population-based retrospective cohort study06. Association between resection approach and transfusion exposure in liver resection for gastrointestinal cancer07. The association between surgeon volume and use of laparoscopic liver resection for gastrointestinal cancer08. Immune suppression through TIGIT in colorectal cancer liver metastases09. “The whole is greater than the sum of its parts” — a combined strategy to reduce postoperative pancreatic fistula after pancreaticoduodenectomy10. Laparoscopic versus open synchronous colorectal and hepatic resection for metastatic colorectal cancer11. Identifying prognostic factors for overall survival in patients with recurrent disease following liver resection for colorectal cancer metastasis12. Modified Blumgart pancreatojejunostomy with external stenting in laparoscopic Whipple reconstruction13. Laparoscopic versus open pancreaticoduodenectomy: a single centre’s initial experience with introduction of a novel surgical approach14. Neoadjuvant chemotherapy versus upfront surgery for borderline resectable pancreatic cancer: a single-centre cohort analysis15. Thermal ablation and telemedicine to reduce resource utilization during the COVID-19 pandemic16. Cost-utility analysis of normothermic machine perfusion compared with static cold storage in liver transplantation in the Canadian setting17. Impact of adjuvant therapy on overall survival in early-stage ampullary cancers: a single-centre retrospective review18. Presence of biliary anaerobes enhances response to neoadjuvant chemotherapy in pancreatic ductal adenocarcinoma19. How does tumour viability influence the predictive capability of the Metroticket model? Comparing predicted-to-observed 5-year survival after liver transplant for hepatocellular carcinoma20. Does caudate resection improve outcomes in patients undergoing curative resection for perihilar cholangiocarcinoma? A systematic review and meta-analysis21. Appraisal of multivariable prognostic models for postoperative liver decompensation following partial hepatectomy: a systematic review22. Predictors of postoperative liver decompensation events following resection in patients with cirrhosis and hepatocellular carcinoma: a population-based study23. Characteristics of bacteriobilia and impact on outcomes after Whipple procedure01. Inverting the y-axis: the future of MIS abdominal wall reconstruction is upside down02. Progressive preoperative pneumoperitoneum: a single-centre retrospective study03. The role of radiologic classification of parastomal hernia as a predictor of the need for surgical hernia repair: a retrospective cohort study04. Comparison of 2 fascial defect closure methods for laparoscopic incisional hernia repair01. Hypoalbuminemia predicts serious complications following elective bariatric surgery02. Laparoscopic adjustable gastric band migration inducing jejunal obstruction associated with acute pancreatitis: aurgical approach of band removal03. Can visceral adipose tissue gene expression determine metabolic outcomes after bariatric surgery?04. Improvement of kidney function in patients with chronic kidney disease and severe obesity after bariatric surgery: a systematic review and meta-analysis05. A prediction model for delayed discharge following gastric bypass surgery06. Experiences and outcomes of Indigenous patients undergoing bariatric surgery: a mixed-methods scoping review07. What is the optimal common channel length in revisional bariatric surgery?08. Laparoscopic management of internal hernia in a 34-week pregnant woman09. Characterizing timing of postoperative complications following elective Roux-en-Y gastric bypass and sleeve gastrectomy10. Canadian trends in bariatric surgery11. Common surgical stapler problems and how to correct them12. Management of choledocholithiasis following Roux-en-Y gastric bypass: a systematic review and meta-analysis. Can J Surg 2021; 64:S80-S159. [PMID: 35483046 PMCID: PMC8677574 DOI: 10.1503/cjs.021321] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
3
|
Assisted breeding technology in the saltwater crocodile Crocodylus porosus: a review and look to the future. Reprod Fertil Dev 2021; 33:503-518. [PMID: 33581743 DOI: 10.1071/rd20217] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 11/01/2020] [Indexed: 12/11/2022] Open
Abstract
This review reports the current status of artificial breeding technology in the Crocodylia and the future requirements for the establishment of AI in the saltwater crocodile. Although there are challenges regarding safe restraint and immobilisation, semen collection of the saltwater crocodile by manual stimulation has proven effective in yielding sufficient volume and sperm concentrations for empirical and molecular analyses of sperm preservation and physiology. Nevertheless, there is still much to learn with respect to fundamental anatomy, physiology and behaviour in both sexes, but particularly in the female. Although lessons can be learned from successful AI in the alligator, the details of this research are not readily accessible. Future research needs to focus on the proximate factors of seasonality and the underlying control of the female's annual reproductive cycle; this will require novel and innovative ways to collect blood samples without causing stress or injury, and ideally a dedicated crocodile research breeding colony. Because the saltwater crocodile is a farmed species, there is likely to be sufficient impetus for the application of assisted breeding technology to drive future productivity in the industry. These developments will also have benefits for the genetic and reproductive management of endangered captive populations.
Collapse
|
4
|
The Australian saltwater crocodile (Crocodylus porosus) provides evidence that the capacitation of spermatozoa may extend beyond the mammalian lineage. Proc Biol Sci 2017; 283:rspb.2016.0495. [PMID: 27147099 DOI: 10.1098/rspb.2016.0495] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 04/11/2016] [Indexed: 01/08/2023] Open
Abstract
Although mammalian spermatozoa only acquire functional maturity as they are conveyed through the male (epididymal maturation) and female (capacitation) reproductive tracts, the degree of post-testicular development necessary to achieve fertilization in other vertebrate species remains far less clear. Indeed, despite reports that the epididymis of birds and reptiles is capable of secreting proteins that bind and modify the sperm surface characteristics, it remains unclear whether capacitation is a pre-requisite for fertilization in these species. Using the ancient reptilian Australian saltwater crocodile as a model, this study was undertaken to explore whether reptile sperm do undergo capacitation-like changes following ejaculation. Our studies revealed that crocodile spermatozoa experienced a rapid and sustained, cyclic-AMP mediated increase in progressive motility following incubation under conditions optimized for the induction of capacitation in mammalian species such as the mouse and human. This response was coupled with elevated levels of phosphorylation associated with both protein kinase A and tyrosine kinase substrates, the latter of which were predominantly localized within the sperm flagellum. In findings that also accord with mammalian spermatozoa, we confirmed a homologue of outer dense fibre 2 as one of the principal substrates for tyrosine phosphorylation. Overall, our findings support the concept that crocodile spermatozoa do undergo a process that is homologous to capacitation in preparation for fertilization of an ovum.
Collapse
|
5
|
Cryopreservation of saltwater crocodile (Crocodylus porosus) spermatozoa. Reprod Fertil Dev 2017; 29:2235-2244. [DOI: 10.1071/rd16511] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 02/21/2017] [Indexed: 11/23/2022] Open
Abstract
The aim of the present study was to develop a protocol for the successful cryopreservation of Saltwater crocodile spermatozoa. Sperm cells were frozen above liquid nitrogen vapour in phosphate-buffered saline (PBS) containing either 0.3 M trehalose, 0.3 M raffinose or 0.3 M sucrose and compared with glycerol (0.3–2.7 M). Although the highest levels of mean post-thaw motility were observed following cryopreservation in 0.3 M trehalose (7.6%) and 0.3 M sucrose (7.3%), plasma membrane integrity (PI) was best following cryopreservation in 2.7 M glycerol (52.5%). A pilot study then assessed the cytotoxicity of glycerol and sucrose prior to cryopreservation and revealed no loss of survival when spermatozoa were diluted in 0.68 M glycerol or 0.2–0.3 M sucrose once cryoprotectants were washed out with PBS or Biggers, Whitten and Whittingham medium containing sperm capacitation agents (BWWCAP). A final study refined the combined use of permeating (0.68 or 1.35 M glycerol) and non-permeating (0.2 or 0.3 M sucrose) cryoprotectants. Spermatozoa were cryopreserved in liquid nitrogen vapour at rates of approximately −21°C min−1 (fast freeze) or −6.0°C min−1 (slow freeze). Post-thaw survival was highest with a combination of 0.2 M sucrose and 0.68 M glycerol and when these cryoprotectants were washed out with BWWCAP, regardless of whether spermatozoa were frozen using a fast (motility 14.2 ± 4.7%; PI 20.7 ± 2.0%) or slow (motility 12.0 ± 2.7%; PI 22 ± 4%) cryopreservation rate.
Collapse
|
6
|
A phase I dose escalation study of the tolerability of the oral VEGFR and EGFR inhibitor vandetanib in combination with the oral MEK1/2 inhibitor selumetinib in solid tumors. Ann Oncol 2016. [DOI: 10.1093/annonc/mdw383.61] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
7
|
The optimal organization of gynecologic oncology services: a systematic review. ACTA ACUST UNITED AC 2015; 22:e282-93. [PMID: 26300679 DOI: 10.3747/co.22.2482] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND A system-level organizational guideline for gynecologic oncology was identified by a provincial cancer agency as a key priority based on input from stakeholders, data showing more limited availability of multidisciplinary or specialist care in lower-volume than in higher-volume hospitals in the relevant jurisdiction, and variable rates of staging for ovarian and endometrial cancer patients. METHODS A systematic review assessed the relationship of the organization of gynecologic oncology services with patient survival and surgical outcomes. The electronic databases medline and embase (ovid: 1996 through 9 January 2015) were searched using terms related to gynecologic malignancies combined with organization of services, patterns of care, and various facility and physician characteristics. Outcomes of interest included overall or disease-specific survival, short-term survival, adequate staging, and degree of cytoreduction or optimal cytoreduction (or both) for ovarian cancer patients by hospital or physician type, and rate of discrepancy in initial diagnoses and intraoperative consultation between non-specialist pathologists and gyne-oncology-specialist pathologists. RESULTS One systematic review and sixteen additional primary studies met the inclusion criteria. The evidence base as a whole was judged to be of lower quality; however, a trend toward improved outcomes with centralization of gynecologic oncology was found, particularly with respect to the gynecologic oncology care of patients with advanced-stage ovarian cancer. CONCLUSIONS Improvements in outcomes with centralization of gynecologic oncology services can be attributed to a number of factors, including access to specialist care and multidisciplinary team management. Findings of this systematic review should be used with caution because of the limitations of the evidence base; however, an expert consensus process made it possible to create recommendations for implementation.
Collapse
|
8
|
Optimisation of preoperative assessment in patients diagnosed with rectal cancer. Clin Oncol (R Coll Radiol) 2015; 27:225-45. [PMID: 25656631 DOI: 10.1016/j.clon.2015.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 11/18/2014] [Accepted: 01/06/2015] [Indexed: 12/14/2022]
Abstract
AIMS Treatment decision making for patients with rectal cancer is complex and optimal preoperative assessment is important to ensure patients receive appropriate and high-quality care. Therefore, our objective was to develop an evidence-based, multidisciplinary guideline to assist physicians treating rectal cancer to ensure that preoperative assessment is optimal. MATERIALS AND METHODS A multidisciplinary expert panel of physicians who treat rectal cancer was selected as members of the Cancer Care Ontario Preoperative Assessment for Rectal Cancer Guideline Development Group (GDG). This group initially met to identify important clinical questions with respect to optimisation of preoperative assessment in patients diagnosed with rectal cancer. A systematic review, specific to each of these clinical questions, was then conducted using MEDLINE, EMBASE and the Cochrane Library databases. The GDG met at regular intervals to review the evidence and to develop guidelines to address each of the clinical questions. RESULTS The GDG identified seven important clinical questions with respect to the optimisation of preoperative assessment in patients diagnosed with rectal cancer. The clinical questions pertained to: (i) investigations required to assess distant metastasis (one question); (ii) imaging for local staging of rectal cancer (five questions); (iii) multidisciplinary cancer conference (MCC) (one question); (iv) restaging-magnetic resonance imaging (one question). The systematic reviews related to these clinical questions yielded 31 articles that were abstracted and reviewed by the GDG. Based on the systematic reviews, a guideline was developed containing seven recommendations that were either adapted from existing guidelines, based on review of the evidence or by consensus when evidence was limited. CONCLUSIONS A set of seven recommendations have been developed in order to optimise pretreatment assessment in patients with rectal cancer by promoting evidence-based practice. These guidelines are based on the best available evidence and have been peer reviewed by two independent multidisciplinary expert panels for relevance and validity.
Collapse
|
9
|
Canadian Surgery Forum: Abstracts of presentations to the Annual Meetings of the Canadian Association of Bariatric Physicians and Surgeons, Canadian Association of General Surgeons, Canadian Association of Thoracic Surgeons, Canadian Hepato-Pancreato-Biliary Society, Canadian Society of Surgical Oncology, Canadian Society of Colon and Rectal Surgeons, London, Ont. Sept. 15-18, 2011. Can J Surg 2011; 54:S57-S104. [PMID: 35488394 PMCID: PMC3191910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023] Open
|
10
|
|
11
|
Abstract
Congenital Toxoplasma gondii infection can result in intracranial calcification, hydrocephalus, and retinochoroiditis. Acquired infection is commonly associated with ocular disease. Pathology is characterized by strong pro-inflammatory responses. Ligation of ATP by purinergic receptor P2X7, encoded by P2RX7, stimulates pro-inflammatory cytokines and can lead directly to killing of intracellular pathogens. To determine whether P2X7 plays a role in susceptibility to congenital toxoplasmosis, we examined polymorphisms at P2RX7 in 149 child/parent trios from North America. We found association (FBAT Z scores ±2.429; P= 0.015) between the derived C(+)G(−) allele (f= 0.68; OR= 2.06; 95% CI: 1.14–3.75) at SNP rs1718119 (1068T>C; Thr-348-Ala), and a second synonymous variant rs1621388 in linkage disequilibrium with it, and clinical signs of disease per se. Analysis of clinical sub-groups showed no association with hydrocephalus, with effect sizes for associations with retinal disease and brain calcifications enhanced (OR=3.0 to 4.25; 0.004<P<0.009) when hydrocephalus was removed from the analysis. Association with toxoplasmic retinochoroiditis was replicated (FBAT Z scores ±3.089; P= 0.002) in a small family-based study (60 families; 68 affected offspring) of acquired infection in Brazil, where the ancestral T(+) allele (f= 0.296) at SNP rs1718119 was strongly protective (OR= 0.27; 95% CI: 0.09–0.80). (Words 194)
Collapse
|
12
|
Abstract
A consensus conference on neurofibromatosis 2 (NF2) was held in 2002 at the request of the United Kingdom (UK) Neurofibromatosis Association, with particular emphasis on vestibular schwannoma (VS) surgery. NF2 patients should be managed at specialty treatment centres, whose staff has extensive experience with the disease. All NF2 patients and their families should have access to genetic testing because presymptomatic diagnosis improves the clinical management of the disease. Some clinical manifestations of NF2, such as ocular abnormalities, can be detected in infancy; therefore, clinical screening for at-risk members of NF2 families can start at birth, with the first magnetic resonance (MRI) scan at 10-12 years of age. Minimal interference, maintenance of quality of life, and conservation of function or auditory rehabilitation are the cornerstones of NF2 management, and the decision points to achieve these goals for patients with different clinical presentations are discussed.
Collapse
|
13
|
Abstract
A 16-year-old boy presented with bilateral arcus cornealis and markedly decreased plasma high density lipoprotein cholesterol. The plasma lipoprotein abnormalities, as well as decreased mass and activity of lecithin:cholesterol acyltransferase (LCAT), were similar to those described in patients with fish eye disease. Increased number of target cells and decreased osmotic fragility of the proband's erythrocytes were noted. The proband's father and one of his brothers showed intermediate plasma lipoprotein and LCAT alterations. The father's erythrocytes also showed abnormal osmotic fragility. The mother of the propositus had normal plasma lipoproteins and erythrocyte osmotic fragility, but her LCAT activity was also low. Many of these features suggest a disorder similar to fish eye disease which is clinically and biochemically distinct from other hypoalphalipoproteinemias.
Collapse
|
14
|
Enzymes of type II fatty acid synthesis and apicoplast differentiation and division in Eimeria tenella. Int J Parasitol 2006; 37:33-51. [PMID: 17112527 PMCID: PMC2803676 DOI: 10.1016/j.ijpara.2006.10.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2006] [Revised: 09/26/2006] [Accepted: 10/03/2006] [Indexed: 11/16/2022]
Abstract
Apicomplexan parasites, Eimeria tenella, Plasmodium spp. and Toxoplasma gondii, possess a homologous plastid-like organelle termed the apicoplast, derived from the endosymbiotic enslavement of a photosynthetic alga. However, currently no eimerian nuclear encoded apicoplast targeted proteins have been identified, unlike in Plasmodium spp. and T. gondii. In this study, we demonstrate that nuclear encoded enoyl reductase of E. tenella (EtENR) has a predicted N-terminal bipartite transit sequence, typical of apicoplast-targeted proteins. Using a combination of immunocytochemistry and EM we demonstrate that this fatty acid biosynthesis protein is located in the apicoplast of E. tenella. Using the EtENR as a tool to mark apicoplast development during the Eimeria lifecycle, we demonstrate that nuclear and apicoplast division appear to be independent events, both organelles dividing prior to daughter cell formation, with each daughter cell possessing one to four apicoplasts. We believe this is the first report of multiple apicoplasts present in the infectious stage of an apicomplexan parasite. Furthermore, the microgametes lacked an identifiable apicoplast consistent with maternal inheritance via the macrogamete. It was found that the size of the organelle and the abundance of EtENR varied with developmental stage of the E. tenella lifecycle. The high levels of EtENR protein observed during asexual development and macrogametogony is potentially associated with the increased synthesis of fatty acids required for the rapid formation of numerous merozoites and for the extracellular development and survival of the oocyst. Taken together the data demonstrate that the E. tenella apicoplast participates in type II fatty acid biosynthesis with increased expression of ENR during parasite growth. Apicoplast division results in the simultaneous formation of multiple fragments. The division mechanism is unknown, but is independent of nuclear division and occurs prior to daughter formation.
Collapse
|
15
|
Abstract
BACKGROUND A multicenter study was conducted to test the ability of electrical impedance scanning to differentiate between benign and malignant skin lesions. The performance of a dual electrical impedance scanning/image analysis device was also assessed. METHODS Electrical impedance scanning measurements of 449 preoperative lesions found on 382 patients and including 53 melanomas from the trunk and extremities were performed. Results were correlated with histopathologic findings. In addition, ABCD parameters for the lesions were automatically calculated by the system. RESULTS Electrical impedance scanning detected melanomas of the trunk and extremities with 91 percent sensitivity and 64 percent specificity. Moreover, sensitivity of electrical impedance scanning was increased to 100 percent for in situ and thin melanomas of smaller size (n = 27). Visual examination identified as malignant only 67 percent of these early tumors (p = 0.002). Clinical examination detected 96 percent of the larger or thicker melanomas (n = 26), whereas electrical impedance scanning detected only 81 percent of them. Combined electrical impedance scanning and image analysis detected 100 percent of the melanomas, independent of their thickness, and with no significant decrease of specificity. Because of electrical differences between the head/neck and the rest of the body, the assessed electrical impedance scanning parameters were not adequate for the diagnosis of melanomas from the head and neck. CONCLUSIONS A validation study proved the value of electrical impedance scanning as a noninvasive technique for detection of melanoma lesions of the trunk and extremities, specifically, of in situ and thin type. In addition, image analysis was shown to be a valuable, complementary procedure. New parameters should be designed to optimize the performance of electrical impedance scanning for melanomas of the head and neck.
Collapse
|
16
|
Abstract
X-ray transmission tests were performed on a Green-Lite (Infab Corporation) apron/vest combination, and compared to a number of other apron/vest combinations routinely used at Christchurch Hospital as well as a sheet of 0.5 mm lead. The materials were X-rayed using the primary beam of a Philips Optimus 50 X-ray machine over an energy range of 50-125 kVp. The entrance and exit doses were recorded and percentage transmission calculated for each kVp. The Green-Lite apron/vest (labelled as 0.5 mm lead at 85 kVp) relies on the overlap at the front to provide the nominal 0.5 mm protection for both the vest and the apron. It performed significantly worse than 0.5 mm of lead and other 0.5 mm lead equivalent apron/vest combinations and provided between 0.3 and 0.39 mm lead equivalent protection depending on the energy used. Vests from other manufacturers all achieved 0.5 mm lead equivalence for a single layer of vest material over the range of energies tested and so were comparable to 1.0 mm lead when doubled. Some aprons relied on a double layer of material to achieve the 0.5 mm lead equivalence (which was not always made clear on the label), while others stated their lead equivalence for a single layer. This resulted in some confusion among wearers of the aprons as to which apron was better.
Collapse
|
17
|
Toxoplasma gondiidense granule protein 3 (GRA3) is a type I transmembrane protein that possesses a cytoplasmic dilysine (KKXX) endoplasmic reticulum (ER) retrieval motif. Parasitology 2005; 131:169-79. [PMID: 16149193 DOI: 10.1017/s0031182005007559] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Studies using antibodies to immunolocalize theToxoplasma gondiidense granule protein GRA3, have shown that this protein associates strongly with the parasitophorous vacuole membrane (PVM). However, as there was no predicted membrane-spanning domain this highlighted an unanswered paradox. We demonstrate that the previously published sequence for GRA3 is actually an artificial chimera of 2 proteins. One protein, of molecular weight 65 kDa, shares the C-terminus with published GRA3 and possesses no significant sequence similarity with any protein thus far deposited in Genbank. The second, with a predicted molecular weight of 24 kDa shares the N-terminal region, is recognized by the monoclonal antibody 2H11 known to react with the dense granules ofT. gondiiand is therefore the authentic GRA3. The corrected GRA3 has an N-terminal secretory signal sequence and a transmembrane domain consistent with its insertion into the PVM. Antibodies to recombinant GRA3 recognize a protein of 24 kDa inT. gondiiexcretory–secretory antigen preparations. The signal peptide is necessary and sufficient to target GFP to the dense granules and parasitophorous vacuole. A homologue was identified inNeospora caninum. Finally, GRA3 possesses a dilysine ‘KKXX’ endoplasmic reticulum (ER) retrieval motif that rationalizes its association with PVM and possibly the host cell ER.
Collapse
|
18
|
Abstract
The shikimate pathway is essential for survival of the apicomplexan parasites Plasmodium falciparum, Toxoplasma gondii and Cryptosporidium parvum. As it is absent in mammals it is a promising therapeutic target. Herein, we describe the genes encoding the shikimate pathway enzymes in T. gondii. The molecular arrangement and phylogeny of the proteins suggests homology with the eukaryotic fungal enzymes, including a pentafunctional AROM. Current rooting of the eukaryotic evolutionary tree infers that the fungi and apicomplexan lineages diverged deeply, suggesting that the arom is an ancient supergene present in early eukaryotes and subsequently lost or replaced in a number of lineages.
Collapse
|
19
|
Abstract
To eliminate apicomplexan parasites, inhibitory compounds must cross host cell, parasitophorous vacuole, and parasite membranes and cyst walls, making delivery challenging. Here, we show that short oligomers of arginine enter Toxoplasma gondii tachyzoites and encysted bradyzoites. Triclosan, which inhibits enoyl-ACP reductase (ENR), conjugated to arginine oligomers enters extracellular tachyzoites, host cells, tachyzoites inside parasitophorous vacuoles within host cells, extracellular bradyzoites, and bradyzoites within cysts. We identify, clone, and sequence T. gondii enr and produce and characterize enzymatically active, recombinant ENR. This enzyme has the requisite amino acids to bind triclosan. Triclosan released after conjugation to octaarginine via a readily hydrolyzable ester linkage inhibits ENR activity, tachyzoites in vitro, and tachyzoites in mice. Delivery of an inhibitor to a microorganism via conjugation to octaarginine provides an approach to transporting antimicrobials and other small molecules to sequestered parasites, a model system to characterize transport across multiple membrane barriers and structures, a widely applicable paradigm for treatment of active and encysted apicomplexan and other infections, and a generic proof of principle for a mechanism of medicine delivery.
Collapse
|
20
|
|
21
|
Fatty acid and sterol metabolism: potential antimicrobial targets in apicomplexan and trypanosomatid parasitic protozoa. Mol Biochem Parasitol 2003; 126:129-42. [PMID: 12615312 DOI: 10.1016/s0166-6851(02)00280-3] [Citation(s) in RCA: 210] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Current treatments for diseases caused by apicomplexan and trypanosomatid parasites are inadequate due to toxicity, the development of drug resistance and an inability to eliminate all life cycle stages of these parasites from the host. New therapeutics agents are urgently required. It has recently been demonstrated that type II fatty acid biosynthesis occurs in the plastid of Plasmodium falciparum and Toxoplasma gondii and inhibitors of this pathway such as triclosan and thiolactomycin restrict their growth. Furthermore, Trypanosoma brucei has recently been demonstrated to use type II fatty acid biosynthesis for myristate synthesis and to be susceptible to thiolactomycin. As this pathway is absent from mammals, it may provide an excellent target for novel antimicrobial agents to combat these diverse parasites. Leishmania and Trypanosoma parasites produce ergosterol-related sterols by a biosynthetic pathway similar to that operating in pathogenic fungi and their growth is susceptible to sterol biosynthesis inhibitors. Thus, inhibition of squalene 2,3-epoxidase by terbinafine, 14alpha-methylsterol 14-demethylase by azole and triazole compounds and delta(24)-sterol methyl transferase by azasterols all cause a depletion of normal sterols and an accumulation of abnormal amounts of sterol precursors with cytostatic or cytoxic consequences. However, Leishmania parasites can survive with greatly altered sterol profiles induced by continuous treatment with low concentrations of some inhibitors and they also have some ability to utilise and metabolise host sterol. These properties may permit the parasites to evade treatment with sterol biosynthesis inhibitors in some clinical situations and need to be taken into account in the design of future drugs.
Collapse
|
22
|
Abstract
Ground-based observations have shown that Jupiter is a two-component source of microwave radio emission: thermal atmospheric emission and synchrotron emission from energetic electrons spiralling in Jupiter's magnetic field. Later in situ measurements confirmed the existence of Jupiter's high-energy electron-radiation belts, with evidence for electrons at energies up to 20[?]MeV. Although most radiation belt models predict electrons at higher energies, adiabatic diffusion theory can account only for energies up to around 20[?]MeV. Unambiguous evidence for more energetic electrons is lacking. Here we report observations of 13.8[?]GHz synchrotron emission that confirm the presence of electrons with energies up to 50[?]MeV; the data were collected during the Cassini fly-by of Jupiter. These energetic electrons may be repeatedly accelerated through an interaction with plasma waves, which can transfer energy into the electrons. Preliminary comparison of our data with model results suggests that electrons with energies of less than 20[?]MeV are more numerous than previously believed.
Collapse
|
23
|
Construction and validation of a polycompetitor construct (SWITCH) for use in competitive RT-PCR to assess tachyzoite-bradyzoite interconversion in Toxoplasma gondii. Parasitology 2001; 123:433-9. [PMID: 11719953 DOI: 10.1017/s003118200100868x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The obligate intracellular protozoan parasite, Toxoplasma gondii exists as 2 life-cycle forms in intermediate hosts. The rapidly dividing tachyzoites responsible for acute disease, present in the first 14 days of infection, give rise to slowly dividing bradyzoites that reside in tissue cysts. Reactivation of disease is associated with conversion of bradyzoites to tachyzoites. A sensitive method for detection and assessment of the number of each life-cycle stage would be useful for following these events. Herein we describe the construction and validation of a plasmid (pSWITCH) containing a polycompetitor construct (SWITCH) for use in competitive reverse transcriptase-PCR (cRT-PCR). pSWITCH contains competitors for SAG2A and LDH2 genes, which are exclusively expressed by tachyzoite and bradyzoite stages respectively, and for beta-tubulin, a gene expressed by both stages. Using cRT-PCR, samples can first be accurately normalized for expression of the housekeeping gene, beta-tubulin and then the relative levels of SAG2A and LDH2 expression compared to follow stage conversion. The abundance of transcripts for other genes of interest can then be followed during this process as demonstrated here for the SAG2-related family of genes. This technique offers a powerful tool for studying the processes involved in tachyzoite and bradyzoite interconversion.
Collapse
|
24
|
Abstract
OBJECTIVE The impact of chronic illness is influenced not just by physical symptoms but also by psychosocial factors. The aim of this study was to determine the concerns of inflammatory bowel disease (IBD) patients in a clinical sample, if concerns differ between patients from varied clinical and demographic variables, and if concerns influence well-being beyond the influence of physical symptoms. METHODS Subjects (n = 259) completed a validated measure of concerns specific to IBD and provided demographic and disease-related information. RESULTS The most intense concerns involved both physical (e.g., energy level) and psychosocial issues (e.g., achieving full potential). There were numerous differences in disease concerns based on ability to work but none based on disease duration. Factor analysis yielded three indices: body image and interpersonal concerns, general physical impact, and disease stigma. Age and education only affected certain concern indices in subgroups of patients. Greater concerns negatively influenced well-being beyond the influence of physical symptoms. CONCLUSION Psychosocial factors, in addition to physical symptoms, play an important role on the impact of illness in patients with IBD.
Collapse
|
25
|
Abstract
OBJECTIVE The impact of chronic illness is influenced not just by physical symptoms but also by psychosocial factors. The aim of this study was to determine the concerns of inflammatory bowel disease (IBD) patients in a clinical sample, if concerns differ between patients from varied clinical and demographic variables, and if concerns influence well-being beyond the influence of physical symptoms. METHODS Subjects (n = 259) completed a validated measure of concerns specific to IBD and provided demographic and disease-related information. RESULTS The most intense concerns involved both physical (e.g., energy level) and psychosocial issues (e.g., achieving full potential). There were numerous differences in disease concerns based on ability to work but none based on disease duration. Factor analysis yielded three indices: body image and interpersonal concerns, general physical impact, and disease stigma. Age and education only affected certain concern indices in subgroups of patients. Greater concerns negatively influenced well-being beyond the influence of physical symptoms. CONCLUSION Psychosocial factors, in addition to physical symptoms, play an important role on the impact of illness in patients with IBD.
Collapse
|
26
|
The child with congenital toxoplasmosis. CURRENT CLINICAL TOPICS IN INFECTIOUS DISEASES 2001; 20:189-208. [PMID: 10943525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
|
27
|
Triclosan inhibits the growth of Plasmodium falciparum and Toxoplasma gondii by inhibition of apicomplexan Fab I. Int J Parasitol 2001; 31:109-13. [PMID: 11239932 DOI: 10.1016/s0020-7519(01)00111-4] [Citation(s) in RCA: 152] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fab I, enoyl acyl carrier protein reductase (ENR), is an enzyme used in fatty acid synthesis. It is a single chain polypeptide in plants, bacteria, and mycobacteria, but is part of a complex polypeptide in animals and fungi. Certain other enzymes in fatty acid synthesis in apicomplexan parasites appear to have multiple forms, homologous to either a plastid, plant-like single chain enzyme or more like the animal complex polypeptide chain. We identified a plant-like Fab I in Plasmodium falciparum and modelled the structure on the Brassica napus and Escherichia coli structures, alone and complexed to triclosan (5-chloro-2-[2,4 dichlorophenoxy] phenol]), which confirmed all the requisite features of an ENR and its interactions with triclosan. Like the remarkable effect of triclosan on a wide variety of bacteria, this compound markedly inhibits growth and survival of the apicomplexan parasites P. falciparum and Toxoplasma gondii at low (i.e. IC50 congruent with150-2000 and 62 ng/ml, respectively) concentrations. Discovery and characterisation of an apicomplexan Fab I and discovery of triclosan as lead compound provide means to rationally design novel inhibitory compounds.
Collapse
|
28
|
Genotypic and phenotypic spectrum in tricho-rhino-phalangeal syndrome types I and III. Am J Hum Genet 2001; 68:81-91. [PMID: 11112658 PMCID: PMC1234936 DOI: 10.1086/316926] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2000] [Accepted: 10/20/2000] [Indexed: 11/03/2022] Open
Abstract
Tricho-rhino-phalangeal syndrome (TRPS) is characterized by craniofacial and skeletal abnormalities. Three subtypes have been described: TRPS I, caused by mutations in the TRPS1 gene on chromosome 8; TRPS II, a microdeletion syndrome affecting the TRPS1 and EXT1 genes; and TRPS III, a form with severe brachydactyly, due to short metacarpals, and severe short stature, but without exostoses. To investigate whether TRPS III is caused by TRPS1 mutations and to establish a genotype-phenotype correlation in TRPS, we performed extensive mutation analysis and evaluated the height and degree of brachydactyly in patients with TRPS I or TRPS III. We found 35 different mutations in 44 of 51 unrelated patients. The detection rate (86%) indicates that TRPS1 is the major locus for TRPS I and TRPS III. We did not find any mutation in the parents of sporadic patients or in apparently healthy relatives of familial patients, indicating complete penetrance of TRPS1 mutations. Evaluation of skeletal abnormalities of patients with TRPS1 mutations revealed a wide clinical spectrum. The phenotype was variable in unrelated, age- and sex-matched patients with identical mutations, as well as in families. Four of the five missense mutations alter the GATA DNA-binding zinc finger, and six of the seven unrelated patients with these mutations may be classified as having TRPS III. Our data indicate that TRPS III is at the severe end of the TRPS spectrum and that it is most often caused by a specific class of mutations in the TRPS1 gene.
Collapse
|
29
|
Histopathological features of ocular toxoplasmosis in the fetus and infant. ARCHIVES OF OPHTHALMOLOGY (CHICAGO, ILL. : 1960) 2001; 119:51-8. [PMID: 11146726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
BACKGROUND Ocular disease is a frequent manifestation of congenital Toxoplasma gondii infection. There are only limited data available in the literature concerning early stages of this disease in fetuses and infants. The purpose of our study was to characterize histopathological features in the eyes of 10 fetuses and 2 infants with congenital toxoplasmosis. METHODS Fifteen eyes from 10 fetuses, 3 eyes from 2 premature infants, and both eyes from a 2-year-old child with congenital toxoplasmosis were examined by light microscopy. Immunohistochemical analysis to identify inflammatory cells and T gondii antigens was performed. The findings in infected eyes were compared with those of age-matched control eyes. RESULTS Retinitis (10/18 eyes), retinal necrosis (4/18 eyes), disruption of the retinal pigment epithelium (12/18 eyes), and choroidal inflammation and congestion (15/18 eyes) were characteristic findings. Optic neuritis was present in 5 of 8 fetal eyes with associated optic nerve available for evaluation. An eye obtained from a 32-week-old fetus showed retinal rosettes at the edge of a scar. T cells predominated in retinal lesions and choroid. Parasites were identified by immunohistochemical analysis in 10 of 18 eyes. CONCLUSIONS Ocular toxoplasmosis causes irreversible damage to the retina in utero. The fetus and infant mount inflammatory responses that may contribute to ocular damage. These findings have important implications for serological screening programs and in utero therapy.
Collapse
MESH Headings
- Antigens, CD/immunology
- Antigens, Protozoan/analysis
- B-Lymphocytes/pathology
- CD4-Positive T-Lymphocytes/pathology
- CD8-Positive T-Lymphocytes/pathology
- Child, Preschool
- Gestational Age
- Humans
- Immunoenzyme Techniques
- Infant, Newborn
- Macrophages/pathology
- Optic Neuritis/immunology
- Optic Neuritis/parasitology
- Optic Neuritis/pathology
- Retinal Necrosis Syndrome, Acute/immunology
- Retinal Necrosis Syndrome, Acute/parasitology
- Retinal Necrosis Syndrome, Acute/pathology
- Retinitis/immunology
- Retinitis/parasitology
- Retinitis/pathology
- Toxoplasmosis, Congenital/immunology
- Toxoplasmosis, Congenital/parasitology
- Toxoplasmosis, Congenital/pathology
- Toxoplasmosis, Ocular/immunology
- Toxoplasmosis, Ocular/parasitology
- Toxoplasmosis, Ocular/pathology
Collapse
|
30
|
Mechanisms of induction of human tissue inhibitor of metalloproteinases-1 (TIMP-1) gene expression by all-trans retinoic acid in combination with basic fibroblast growth factor. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:4150-6. [PMID: 10866818 DOI: 10.1046/j.1432-1327.2000.01459.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The addition of all-trans retinoic acid (ATRA) in combination with basic fibroblast growth factor (bFGF) to human fibroblasts results in a synergistic induction of tissue inhibitor of metalloproteinases-1 (TIMP-1) protein production. The synergistic stimulation of TIMP-1 protein by ATRA and bFGF increased across 72 h. An incubation of 10 min to 12 h with bFGF alone followed by ATRA gave a similar synergistic induction of TIMP-1 protein to that seen with both agents together. Treatment of cells with ATRA first followed by bFGF was ineffective. Expression of RARbeta mRNA was induced by ATRA alone, but not further induced by ATRA and bFGF; expression of RARgamma mRNA was induced by both ATRA or bFGF alone, and further induced by both reagents together; expression of RXRgamma was repressed by ATRA alone, but not by ATRA in combination with bFGF. Steady-state levels of TIMP-1 mRNA were induced 14 to 40-fold above control by ATRA and bFGF. Treatment with ATRA and bFGF did not alter the stability of TIMP-1 mRNA. The induction of TIMP-1 mRNA by ATRA and bFGF was greatly diminished by cycloheximide and therefore required new protein synthesis. The tyrosine kinase inhibitor genistein caused a dose-dependent inhibition of TIMP-1 protein induction by ATRA and bFGF. A MEK1 inhibitor (PD98059) inhibited both basal and induced levels of TIMP-1. At high concentrations, p38 MAP kinase inhibitors further enhanced the synergistic stimulation of TIMP-1 protein by ATRA and bFGF, but at these concentrations, p42/44 MAP kinase was strongly activated. These data begin to elucidate the mechanisms by which TIMP-1 gene expression can be upregulated.
Collapse
|
31
|
Hospital procedure volume and teaching status do not influence treatment and outcome measures of rectal cancer surgery in a large general population. J Gastrointest Surg 2000; 4:324-30. [PMID: 10769097 DOI: 10.1016/s1091-255x(00)80083-9] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A clear benefit of increased hospital procedure volume or teaching hospital status on outcomes of rectal cancer surgery has yet to be shown. Few have examined treatment differences that may lead to varying outcomes. This study assessed the impact of hospital procedure volume and teaching status on both treatment and outcome measures of rectal cancer surgery in a large general population. Data were obtained for 1072 incident cases of rectal adenocarcinoma diagnosed in 1990 from Ontario, Canada, and treated with a major resection. Hospitals were classified by teaching status and procedure volume. Pathology reports were examined for 418 procedures. Abdominoperineal resections accounted for 31.0% of all procedures. There were no clinically significant differences in treatment measures, operative mortality, and long-term survival among the hospital groups according to both univariate and multivariate analyses. In conclusion, the absence of a hospital volume or teaching status effect on treatment and outcome measures suggests that for rectal cancer surgery in Ontario, centralization of procedures into high-volume or teaching centers is unlikely to improve surgical quality.
Collapse
|
32
|
Chemoprevention of aflatoxin B1 hepatocarcinogenesis by coumarin, a natural benzopyrone that is a potent inducer of aflatoxin B1-aldehyde reductase, the glutathione S-transferase A5 and P1 subunits, and NAD(P)H:quinone oxidoreductase in rat liver. Cancer Res 2000; 60:957-69. [PMID: 10706111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Structurally diverse compounds can confer resistance to aflatoxin B1 (AFB1) hepatocarcinogenesis in the rat. Treatment with either phytochemicals [benzyl isothiocyanate, coumarin (CMRN), or indole-3-carbinol] or synthetic antioxidants and other drugs (butylated hydroxyanisole, diethyl maleate, ethoxyquin, beta-naphthoflavone, oltipraz, phenobarbital, or trans-stilbene oxide) has been found to increase hepatic aldo-keto reductase activity toward AFB1-dialdehyde and glutathione S-transferase (GST) activity toward AFB1-8,9-epoxide in both male and female rats. Under the conditions used, the natural benzopyrone CMRN was a major inducer of the AFB1 aldehyde reductase (AFAR) and the aflatoxin-conjugating class-alpha GST A5 subunit in rat liver, causing elevations of between 25- and 35-fold in hepatic levels of these proteins. Induction was not limited to AFAR and GSTA5: treatment with CMRN caused similar increases in the amount of the class-pi GST P1 subunit and NAD(P)H: quinone oxidoreductase in rat liver. Immunohistochemistry demonstrated that the overexpression of AFAR, GSTA5, GSTP1, and NAD(P)H:quinone oxidoreductase affected by CMRN is restricted to the centrilobular (periacinar) zone of the lobule, sometimes extending almost as far as the portal tract. This pattern of induction was also observed with ethoxyquin, oltipraz, and trans-stilbene oxide. By contrast, induction of these proteins by beta-naphthoflavone and diethyl maleate was predominantly periportal. Northern blotting showed that induction of these phase II drug-metabolizing enzymes by CMRN was accompanied by similar increases in the levels of their mRNAs. To assess the biological significance of enzyme induction by dietary CMRN, two intervention studies were performed in which the ability of the benzopyrone to inhibit either AFB1-initiated preneoplastic nodules (at 13 weeks) or AFB1-initiated liver tumors (at 50 weeks) was investigated. Animals pretreated with CMRN for 2 weeks prior to administration of AFB1, and with continued treatment during exposure to the carcinogen for a further 11 weeks, were protected completely from development of hepatic preneoplastic lesions by 13 weeks. In the longer-term dietary intervention, treatment with CMRN before and during exposure to AFB1 for a total of 24 weeks was found to significantly inhibit the number and size of tumors that subsequently developed by 50 weeks. These data suggest that consumption of a CMRN-containing diet provides substantial protection against the initiation of AFB1 hepatocarcinogenesis in the rat.
Collapse
|
33
|
Measurement of the efficacy of vaccines and antimicrobial therapy against infection with Toxoplasma gondii. Int J Parasitol 2000; 30:149-55. [PMID: 10704598 DOI: 10.1016/s0020-7519(00)00009-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To facilitate studies of vaccines and antimicrobial agents effective against Toxoplasma gondii infection, an assay system was developed to semi-quantitate parasitaemia using PCR amplification of T. gondii DNA obtained from the blood of mice infected with the parasite. A competitive internal standard DNA fragment of the B1 gene of T. gondii was generated and used in PCR so that the amplified product could be semi-quantitated and false negative results could be avoided. The PCR assay system was used to analyse the levels of parasitaemia in immunised and antimicrobial agent treated mice at various times after infection with T. gondii. The results of these studies indicate that this highly sensitive detection method is a rapid and reliable procedure that can be employed to assess the abilities of vaccines or antimicrobial agents to provide protection early following T. gondii infection.
Collapse
|
34
|
Abstract
OBJECTIVES To determine the effectiveness of medical therapy (including metronidazole, bismuth carbomer enemas, oral probiotic bacteria, butyrate suppositories, and glutamine suppositories) for inducing a response or maintaining remission in pouchitis. SEARCH STRATEGY Studies were selected using the MEDLINE data base (1966 - December 1997), abstracts from major gastrointestinal meetings and references from published articles and reviews. The Cochrane Controlled Trials Register and the Inflammatory Bowel Disease Review Group Trials Register were also searched. SELECTION CRITERIA Four randomized controlled trials of medical therapy in adult patients with pouchitis were identified: two placebo controlled trials in active chronic pouchitis; one maintenance of remission trial comparing two active agents in chronic pouchitis; and one placebo-controlled maintenance of remission trial for chronic pouchitis. A single patient "n-of-1" trial for active chronic pouchitis was excluded. DATA COLLECTION AND ANALYSIS Data were extracted by three independent observers based on the intention to treat principle. Each study was given a quality score based on predetermined criteria. Extracted data were converted to 2X2 tables (response versus no response and medical therapy versus placebo or medical therapy versus medical therapy) and then synthesized in to a summary statistic using the pooled odds ratio and 95% confidence intervals as described by Cochran and Mantel and Haenszel (the "odds ratio" in MetaView). MAIN RESULTS The odds ratios of inducing a response using oral metronidazole or bismuth carbomer foam enemas compared with placebo in active chronic pouchitis were 26.67 (95% CI 2.31-308.01) and 1.00 (95% CI 0.29-3.48), respectively. The numbers needed to treat with these therapies to prevent an additional relapse was 2 for oral metronidazole, and undefined for bismuth carbomer foam enemas (due to equal efficacy between the enema and placebo). The odds ratio of maintaining remission in chronic pouchitis for oral probiotic bacteria (VSL-3) compared with placebo was 205.00 (95% CI 9.89-4247.71), while the number needed to treat to prevent one additional relapse was 2. After discontinuation of suppressive medical therapy for chronic pouchitis, there was no difference in the odds ratio of maintaining symptomatic remission with glutamine suppositories compared to butyrate suppositories, 3. 00 (95% CI 0.46-19.59). The numbers needed to treat with glutamine suppositories to prevent an additional relapse was 4. REVIEWER'S CONCLUSIONS The results presented in this review must be interpreted with extreme caution given the small numbers of trials and patients evaluated for any one comparison. Metronidazole appears to be an effective therapy for active chronic pouchitis. Bismuth carbomer foam enemas may not be an effective therapy for chronic active pouchitis. Oral probiotic therapy with VSL-3 appears to be an effective therapy for maintaining remission in patients with chronic pouchitis in remission. There is no evidence of a difference in the maintenance of symptomatic remission in patients with chronic pouchitis treated with glutamine versus butyrate suppositories, and it is unknown whether glutamine and butyrate are equally effective or ineffective. Additional randomized, double-blind, placebo-controlled, dose-ranging clinical trials are needed to determine the efficacy of empiric medical therapies currently being used in patients with pouchitis.
Collapse
|
35
|
Abstract
There is considerable controversy as to the roles of parasite proliferation and the inflammatory response in destruction of the retina during Toxoplasma gondii infection. A murine model was used to investigate the role of nitric oxide in pathogenesis of chronic ocular toxoplasmosis. Increased quantities of messenger RNA (mRNA) transcripts for iNOS were detected in the eyes of chronically infected C57BL/6 mice compared with noninfected control mice. Inhibition of nitric oxide (NO) by the addition of Lomega-nitro-L-arginine methyl ester (L-NAME) to the drinking water of infected mice between weeks 4-6 of infection, exacerbated ocular inflammation. The amount of inflammation was assessed semiquantitatively in histological sections of the eye. Eyes from L-NAME treated mice showed a significant increase in inflammation of the retina (P = 0.02), choroid (P = 0.03), and vitreous (P = 0.02) compared with control mice. These results demonstrate a protective role for NO in the control of chronic, ocular toxoplasmosis.
Collapse
|
36
|
Self-reported effects of computer workshops on physicians' computer use. THE JOURNAL OF CONTINUING EDUCATION IN THE HEALTH PROFESSIONS 2000; 20:20-26. [PMID: 11232068 DOI: 10.1002/chp.1340200105] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
BACKGROUND The need for physicians to be proficient in the use of computers is undeniable. As computers have become easier to use and more widespread, their use in medicine is expanding. Several organizations have produced continuing medical education programs to teach physicians about the use of computers in medicine but little has been reported on the effects of such programs. METHOD We present the self-reported effects of a series of workshops that taught physicians about basic computer skills: information retrieval, the Internet, CD-ROMs, electronic mail, and computer-aided learning. RESULTS A questionnaire mailed to 65 workshop participants yielded a response rate of 46% (n = 30). Of the 30 respondents, 27% (n = 8) had bought new hardware or software because of attending the workshops, with the most common purchase being a new computer. Fifty-seven percent (n = 17) had increased their use of computers, with the most common applications being use of the Internet for information retrieval and electronic mail.
Collapse
|
37
|
Growth of Toxoplasma gondii is inhibited by aryloxyphenoxypropionate herbicides targeting acetyl-CoA carboxylase. Proc Natl Acad Sci U S A 1999; 96:13387-92. [PMID: 10557330 PMCID: PMC23957 DOI: 10.1073/pnas.96.23.13387] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Aryloxyphenoxypropionates, inhibitors of the plastid acetyl-CoA carboxylase (ACC) of grasses, also inhibit Toxoplasma gondii ACC. Clodinafop, the most effective of the herbicides tested, inhibits growth of T. gondii in human fibroblasts by 70% at 10 microM in 2 days and effectively eliminates the parasite in 2-4 days at 10-100 microM. Clodinafop is not toxic to the host cell even at much higher concentrations. Parasite growth inhibition by different herbicides is correlated with their ability to inhibit ACC enzyme activity, suggesting that ACC is a target for these agents. Fragments of genes encoding the biotin carboxylase domain of multidomain ACCs of T. gondii, Plasmodium falciparum, Plasmodium knowlesi, and Cryptosporidium parvum were sequenced. One T. gondii ACC (ACC1) amino acid sequence clusters with P. falciparum ACC, P. knowlesi ACC, and the putative Cyclotella cryptica chloroplast ACC. Another sequence (ACC2) clusters with that of C. parvum ACC, probably the cytosolic form.
Collapse
|
38
|
Abstract
Associations between Human Leukocyte Antigen (HLA) (i.e. human major histocompatibility complex [MHC]) genes and susceptibility to infections and inflammatory processes have been described, but causal relationships have not been proven. We characterized effects of HLA-DQ alleles on outcome of congenital toxoplasma infection and found that among Caucasians, the DQ3 gene frequency was significantly higher in infected infants with hydrocephalus (0.783) than infected infants without hydrocephalus (0.444) or published normal controls (0.487). We then developed a novel animal model to definitively determine the effect of these HLA DQ molecules on the severity of toxoplasmosis. Human MHC-Class II transgenes reduced parasite burden and necrosis in brains of mice infected with Toxoplasma gondii. Consistent with the observed association between DQ3 and hydrocephalus in human infants, in the murine model the DQ3(DQ8; DQB1*0302) gene protected less than DQ1 (DQ6; DQB1*0601). Our findings definitively prove a cause and effect relationship between human MHC genes and resistance to infection, provide novel means to characterise human immune responses that are protective or pathogenic in infections, and are important for vaccine development.
Collapse
|
39
|
Induction of human tissue inhibitor of metalloproteinase-1 gene expression by all-trans retinoic acid in combination with basic fibroblast growth factor involves both p42/44 and p38 MAP kinases. Ann N Y Acad Sci 1999; 878:506-9. [PMID: 10415756 DOI: 10.1111/j.1749-6632.1999.tb07710.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
40
|
Abstract
The protozoan parasite Toxoplasma gondii is an important cause of ocular disease both in immunosuppressed and immunocompetent individuals. Non-ocular infections are not usually serious in otherwise healthy adults. In contrast, toxoplasmic retinochoroiditis is a progressive, recurring disease that can cause severe morbidity. Here, Fiona Roberts and Rima McLeod review the demography, pathology and clinical findings of this disease. They discuss mechanisms of retinal destruction and disease recurrences, and the local immunological response at this immune-privileged site.
Collapse
|
41
|
Abstract
OBJECTIVE To determine the effectiveness of medical therapy (including metronidazole, bismuth carbomer enemas, oral probiotic bacteria, butyrate suppositories, and glutamine suppositories) for inducing a response or for maintaining remission in pouchitis. SEARCH STRATEGY Studies were selected using the MEDLINE data base (1966-December 1997), abstracts from major gastrointestinal meetings, and references from published articles and reviews. SELECTION CRITERIA Four randomized controlled trials of medical therapy in adult patients with pouchitis were identified: two placebo controlled trials in active chronic pouchitis; one maintenance of remission trial comparing two active agents in chronic pouchitis; and one placebo-controlled maintenance of remission trial for chronic pouchitis. A single patient "n-of-1" trial for active chronic pouchitis was excluded. DATA COLLECTION AND ANALYSIS Data were extracted by three independent observers based on the intention to treat principle. Extracted data were converted to 2 x 2 tables (response versus no response and medical therapy versus placebo or medical therapy versus medical therapy) and an odds ratio with 95% confidence intervals (CI) were determined as described by Cochrane and Mantel and Haenszel. In addition, the absolute risk reduction, relative risk reduction, and number needed to treat were determined. MAIN RESULTS The odds ratios of inducing a response using oral metronidazole or bismuth carbomer foam enemas compared with placebo in active chronic pouchitis were 12.34 (95% CI 2.34-64.95) and 1.00 (95% CI 0.29-3.42), respectively. The odds ratio of maintaining remission in chronic pouchitis for oral probiotic bacteria (VSL-3) compared with placebo was 15.33 (95% CI 4.51-52.14). There was no difference in the odds ratio of inducing symptomatic remission and then maintaining symptomatic remission after discontinuing suppressive medical therapy for chronic pouchitis with glutamine suppositories compared with butyrate suppositories, 2.75 (95% CI 0.48-15.94). CONCLUSIONS Metronidazole is an effective therapy for active chronic pouchitis. Bismuth carbomer foam enemas are not effective therapy for active chronic pouchitis. Oral probiotic therapy with VSL-3 is an effective therapy for maintaining remission in patients with chronic pouchitis in remission. There is no difference in maintenance of symptomatic remission in patients with chronic pouchitis treated with glutamine versus butyrate suppositories, and it is unknown whether glutamine and butyrate are equally effective or ineffective. Additional randomized, double-blind, placebo-controlled, dose-ranging clinical trials are needed to determine the efficacy of empiric medical therapies currently being used in patients with pouchitis.
Collapse
|
42
|
Identification of domains in apolipoprotein B100 that confer a high requirement for the microsomal triglyceride transfer protein. J Biol Chem 1999; 274:1986-93. [PMID: 9890955 DOI: 10.1074/jbc.274.4.1986] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The microsomal triglyceride transfer protein (MTP) is required for the assembly and secretion of apoB-containing lipoproteins. To investigate the role of MTP in lipoprotein assembly, we determined the ability of carboxyl-terminally truncated forms of apoB to be secreted from cells treated with the MTP inhibitor 4'-bromo-3'-methylmetaqualone (Benoist, F., Nicodeme, E., and Grand-Perret, T. (1996) Eur. J. Biochem. 240, 713-720). In Caco-2 and mhAT3F cells that produce apoB100 and apoB48, the inhibitor preferentially blocked apoB100 secretion. When the inhibitor was tested on McA-RH7777 cells stably transfected with cDNAs encoding human apoB100, apoB72, apoB53, apoB29, and apoB18, the secretion of apoB100, apoB72, and apoB53 was preferentially impaired relative to apoB48 and shorter forms. To delineate the region between apoB48 and apoB53 that has a high requirement for MTP, we used puromycin to generate a range of truncated forms of apoB in HepG2 cells. The secretion of apoB53 and longer forms of apoB was markedly affected by low concentrations of the MTP inhibitor (approximately 1 microM), whereas apoB51 and smaller forms of apoB were only affected at higher concentrations (> 10 microM). The size-related sensitivity to MTP inhibitor was not due to late processing or retention, since the same result was observed when nascent lipoproteins were isolated from the endoplasmic reticulum. The MTP inhibitor did not alter the density of the secreted lipoproteins, indicating that each apoB polypeptide requires a minimally defined amount of lipid to attain a secretable conformation. Our results suggest that the folding of the domain between apoB51 and apoB53 has a high requirement for lipid. This domain is predicted to form amphipathic alpha-helices and to bind lipid reversibly. It proceeds and is followed by rigid amphipathic beta-sheets that are predicted to associate with lipid irreversibly. We speculate that these domains enable apoB to switch from a stable lipid-poor conformation in apoB48 to another lipid-rich conformation in apoB100 during lipoprotein assembly.
Collapse
|
43
|
Abstract
BACKGROUND & AIMS Linkage data derived from genome-wide scans of inflammatory bowel disease (IBD) sibling-pair families have identified 4 loci on chromosomes 3, 7, 12, and 16 as potential sites for IBD susceptibility genes. The aim of this study was to investigate whether linkage analysis of another independently collected set of sibling pairs with IBD would provide further evidence of linkage between these previously reported loci and IBD. METHODS Using the MAPMAKER/SIBS program, the segregation of 21 microsatellite marker loci spanning the 4 putative IBD gene loci was analyzed in a study population comprising 161 families with 114 Crohn's disease, 36 ulcerative colitis, and 50 mixed IBD sibling pairs from the Greater Toronto area. RESULTS The results of multipoint linkage analysis showed no evidence for linkage between IBD and each of the 21 marker loci studied; the logarithm of odds scores in all instances were less than 0.8. These linkage data were found, by exclusion mapping analysis, to exclude values of lambdas ranging from 1.5 to 3.0, depending on the locus evaluated. CONCLUSIONS The loci previously suggested as representing IBD susceptibility loci are not linked to IBD in the Toronto population examined in this analysis.
Collapse
|
44
|
Comment: unexpectedly low phenytoin concentration in a patient receiving ciprofloxacin. Ann Pharmacother 1998; 32:1110-1. [PMID: 9793610 DOI: 10.1345/aph.16267c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
|
45
|
Tachykinins in the lungs. DRUG NEWS & PERSPECTIVES 1998; 11:480-9. [PMID: 15616676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Tachykinins are neuropeptides which regulate various biological responses, some of which are potentially important in the pathogenesis of pulmonary diseases such as asthma. Tachykinins produce their biological effects by stimulating specific tachykinin receptors (NK(1), NK(2) and NK(3)). Tachykinins have a variety of effects in the lungs. They are among the most potent bronchoconstrictor agents known and have potent effects on airway blood vessel caliber, causing vasodilation by an endothelium-dependent mechanism. Exogenously administered tachykinins (substance P, neurokinin A and neurokinin B) induce mucus secretion in most species, including humans. In addition to having effects on airway secretion, tachykinins also modulate the mucociliary clearance mechanisms of the airway. Tachykinin receptors are found on pulmonary/bronchial C fibers, and both excitatory and inhibitory effects of tachykinins on neural discharge and neurotransmitter release from these nerves have been described. Tachykinins are also involved in several reflex responses, particularly the cough reflex. Tachykinins have been implicated in the inflammatory response in the lungs and they also participate in the regulation of the immune system. A considerable body of evidence implicates tachykinins as important mediators of the neurogenic inflammatory response in a variety of pulmonary diseases. It is thus expected that tachykinin receptor antagonists will prove useful in the therapy of diseases such as asthma, allergic rhinitis and chronic bronchitis.
Collapse
|
46
|
Abstract
Addition of paclitaxel (Taxol) at a concentration of 1 microM to Toxoplasma gondii-infected human foreskin fibroblasts arrested parasite multiplication. Division of the T. gondii tachyzoite nucleus was inhibited, leading to syncytium-like parasite structures within the fibroblasts by 24 h after infection and treatment of the cultures. By 4 days after infection and treatment of the cultures with paclitaxel, this inhibition was irreversible, since the arrested intracellular form was incapable of leaving the host cell, infecting new cells, and initiating the growth of tachyzoites with normal morphology. Specifically, when paclitaxel was added to infected cells for 4 days and then removed by washing and the infected, paclitaxel-treated cells were cultured for 4 more days, there were no remaining T. gondii organisms with normal morphology. Syncytium-like structures in the cultures that were infected and treated with paclitaxel for 8 days were similar in appearance to those in preparations of infected paclitaxel-treated fibroblasts that had been cultured for 24 to 48 h. Pretreatment of the tachyzoites for 1 h with paclitaxel followed by the removal of the paclitaxel by repeatedly centrifuging and resuspending the parasites in fresh medium without paclitaxel and then adding fresh medium prior to culture of the parasites with fibroblasts did not prevent their invasion of fibroblasts but did affect their subsequent ability to replicate within fibroblasts. Pretreatment of the fibroblasts with paclitaxel also diminished subsequent replication of T. gondii in such host cells after 8 days. Thus, paclitaxel alters the ability of T. gondii to replicate in host cells. Inhibition of parasite microtubules by such compounds at concentrations which do not interfere with the function of host cell microtubules may be useful for development of novel medicines to treat T. gondii infections in the future.
Collapse
|
47
|
Abstract
Parasites of the phylum Apicomplexa cause substantial morbidity, mortality and economic losses, and new medicines to treat them are needed urgently. The shikimate pathway is an attractive target for herbicides and antimicrobial agents because it is essential in algae, higher plants, bacteria and fungi, but absent from mammals. Here we present biochemical, genetic and chemotherapeutic evidence for the presence of enzymes of the shikimate pathway in apicomplexan parasites. In vitro growth of Toxoplasma gondii, Plasmodium falciparum (malaria) and Cryptosporidium parvum was inhibited by the herbicide glyphosate, a well-characterized inhibitor of the shikimate pathway enzyme 5-enolpyruvyl shikimate 3-phosphate synthase. This effect on T. gondii and P. falciparum was reversed by treatment with p-aminobenzoate, which suggests that the shikimate pathway supplies folate precursors for their growth. Glyphosate in combination with pyrimethamine limited T. gondii infection in mice. Four shikimate pathway enzymes were detected in extracts of T. gondii and glyphosate inhibited 5-enolpyruvyl shikimate 3-phosphate synthase activity. Genes encoding chorismate synthase, the final shikimate pathway enzyme, were cloned from T. gondii and P. falciparum. This discovery of a functional shikimate pathway in apicomplexan parasites provides several targets for the development of new antiparasite agents.
Collapse
|
48
|
Regulation of rat glutathione S-transferase A5 by cancer chemopreventive agents: mechanisms of inducible resistance to aflatoxin B1. Chem Biol Interact 1998; 111-112:51-67. [PMID: 9679543 DOI: 10.1016/s0009-2797(97)00151-8] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The rat can be protected against aflatoxin B1 (AFB1) hepatocarcinogenesis by being fed on a diet containing the synthetic antioxidant ethoxyquin. Evidence suggests that chemoprotection against AFB1 is due to increased detoxification of the mycotoxin by one or more inducible drug-metabolising enzymes. The glutathione S-transferase (GST) isoenzymes in rat liver that contribute to ethoxyquin-induced chemoprotection against AFB1 have been identified by protein purification. This approach resulted in the isolation of several heterodimeric class alpha GST, all of which contained the A5 subunit and possessed at least 50-fold greater activity towards AFB1-8,9-epoxide than previously studied transferases. Molecular cloning and heterologous expression of rat GSTA5-5 has led to the demonstration that it exhibits substantially greater activity for AFB1-8,9-epoxide than other rat transferases. The A5 homodimer can also catalyse the conjugation of glutathione with other epoxides, such as trans-stilbene oxide and 1,2-epoxy-3-(4'-nitrophenoxy)propane, and possesses high catalytic activity for the reactive aldehyde 4-hydroxynonenal. Western blotting has shown that the A5 subunit is not only induced by ethoxyquin but that it is also induced by other cancer chemopreventive agents, such as butylated hydroxyanisole, oltipraz, benzyl isothiocyanate, indole-3-carbinol and coumarin. In addition to GSTA5, we have identified a novel aflatoxin-aldehyde reductase (AFAR) that is similarly induced by ethoxyquin. However, immunoblotting has shown that GSTA5 and AFAR are not always co-ordinately regulated by chemoprotectors. In order to gain a better understanding of the mechanisms responsible for the induction of GSTA5 protein, the GSTA5 gene has been cloned. It was isolated on two overlapping bacteriophage lambda clones and found to be approximately 12 kb in length. The transcriptional start site of GSTA5 has been identified 228 bp upstream from the ATG translational initiation codon. Computer-assisted analysis of the upstream sequence has indicated the presence of a putative antioxidant responsive element (located between -421 and -429 bp) which may be responsible for the induction of GSTA5 by chemopreventive agents.
Collapse
|
49
|
Reconstructive surgery for pelvic pouches. World J Surg 1998; 22:342-6. [PMID: 9523514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Restorative proctocolectomy with ileo-pouch-anal anastomosis has become the elective surgical procedure of choice for most of our patients with ulcerative colitis and for selected patients with familial adenomatous polyposis. This report reviews the results of the outcome of patients who have undergone a more radical reconstructive approach for salvage of the pelvic pouch where multiple local procedures have failed. A group of 24 patients were reviewed (19 females, 5 males). The indication for surgery was ulcerative colitis in 22 patients; 10 of the 24 patients were referred from other centers. The 24 patients underwent a mean of 2.9 local salvage procedures per patient. Of the 19 females within the group, 12 had an anastomotic vaginal fistula. The 24 patients were divided into two groups. The first group consisted of 14 patients whose initial pouch was used once again for revisionary surgery. Group 2 comprised 10 patients whose initial pouch was removed and a redo pouch was constructed. Of the 24 patients, only 2 have had their pouches removed. More than 75% of the patients have had a successful outcome using a reconstructive approach. Four patients still have an ileostomy; of these four, two are awaiting closure of their loop ileostomy. Of 18 patients who were evaluable, 13 were considered to have normal daytime continence, and 17 of 18 were sexually functional. Of the 18 evaluable patients, 15 were satisfied with the outcome. Radical reconstructive surgery can be performed where local procedures to effect pouch salvage have failed, and it should be considered as a first-line management where factors dictate that local procedures might fail. The commitment of the surgeon and the patient to achieving a successful outcome is essential. Severe pouch-specific complications can be managed successfully by surgeons who have a specific interest in pelvic pouch surgery and have considerable experience dealing with complications that arise.
Collapse
|
50
|
Functional analysis of disulfide linkages clustered within the amino terminus of human apolipoprotein B. J Biol Chem 1998; 273:7244-51. [PMID: 9516417 DOI: 10.1074/jbc.273.13.7244] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
We tested the involvement of N-terminal six disulfide bonds (Cys-1 through Cys-12) of human apolipoprotein (apo) B in the assembly and secretion of lipoproteins using two C-terminal-truncated apoB variants, namely B50 and B18. In transfected rat hepatoma McA-RH7777 cells, B50 could assemble very low density lipoproteins (VLDL), and B18 was secreted as high density lipoproteins. When all 12 cysteine residues were substituted with alanines in B50, the mutant protein (B50C1-12) lost its ability to assemble lipid and was degraded intracellularly. However, mutation had no effect on B50C1-12 translation or translocation across the microsomal membrane. Post-translational degradation of B50C1-12 was partially inhibited by the proteasome inhibitor MG132. To determine which cysteines were critical in VLDL assembly and secretion, we prepared three additional mutant B50s, each containing four selected Cys-to-Ala substitutions in tandem (i.e. Cys-1 to Cys-4, Cys-5 to Cys-8, and Cys-9 to Cys-12). Expression of these mutants showed that disruption of disulfide bond formation within Cys-5 to Cys-8 diminished apoB secretion, whereas within Cys-1 to Cys-4 or Cys-9 to Cys-12 had lesser or no effect. In another two mutants in which only one disulfide bond (i.e. between Cys-5 and Cys-6 or between Cys-7 and Cys-8) was eliminated, only secretion of B50 with mutations at Cys-7 and Cys-8 was decreased. Thus, the disulfide bond involving Cys-7 and Cys-8 is most important for VLDL assembly and secretion. In addition, assembly and secretion of VLDL containing endogenous B100 or B48 were impaired in cells transfected with B50s containing Cys-7 and Cys-8 mutation. The Cys-to-Ala substitution abolished recognition of B50 by MB19, a conformational antibody with an epitope at the N terminus of human apoB. The Cys-to-Ala substitution also attenuated secretion of B18, but the effect of the mutation on B18 secretion was less evident than on B50.
Collapse
|