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A Potent Kalihinol Analogue Disrupts Apicoplast Function and Vesicular Trafficking in P. falciparum Malaria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.21.568162. [PMID: 38045341 PMCID: PMC10690269 DOI: 10.1101/2023.11.21.568162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Here we report the discovery of MED6-189, a new analogue of the kalihinol family of isocyanoterpene (ICT) natural products. MED6-189 is effective against drug-sensitive and -resistant P. falciparum strains blocking both intraerythrocytic asexual replication and sexual differentiation. This compound was also effective against P. knowlesi and P. cynomolgi. In vivo efficacy studies using a humanized mouse model of malaria confirms strong efficacy of the compound in animals with no apparent hemolytic activity or apparent toxicity. Complementary chemical biology, molecular biology, genomics and cell biological analyses revealed that MED6-189 primarily targets the parasite apicoplast and acts by inhibiting lipid biogenesis and cellular trafficking. Genetic analyses in P. falciparum revealed that a mutation in PfSec13, which encodes a component of the parasite secretory machinery, reduced susceptibility to the drug. The high potency of MED6-189 in vitro and in vivo, its broad range of efficacy, excellent therapeutic profile, and unique mode of action make it an excellent addition to the antimalarial drug pipeline.
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The Importance of Timing of Physical Therapy in Relation to Radiation Therapy during Multimodality Breast Cancer Treatment to Maximize Shoulder Range of Motion. Int J Radiat Oncol Biol Phys 2023; 117:e163. [PMID: 37784762 DOI: 10.1016/j.ijrobp.2023.06.996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Physical therapy (PT) is an effective tool for improving range of motion (ROM) for breast cancer patients to reduce long-term impairment. There is a paucity of data surrounding when PT should be initiated to optimally reduce upper limb disability. We hypothesized that patients who initiated PT early after surgery and before radiation therapy (RT), would experience greater gains in functionality compared to PT during/after RT. MATERIALS/METHODS Demographic/clinical variables were assessed via retrospective chart review for patients referred to outpatient PT and receiving multimodality treatment for breast cancer between January 2015 and August 2021. Three distinct cohorts were established: patients who received PT and no RT, PT initiated before radiation therapy (pre-RT), and PT initiated during/after RT (d/a RT). The primary endpoint was percent change of total ROM of the ipsilateral shoulder between the first and last PT visits. Secondary endpoints included absolute change in degrees of total ROM of the ipsilateral shoulder between first and last PT visits. Associations between ROM across PT groups and baseline characteristics were evaluated with analysis of variance (ANOVA) testing. RESULTS Thirty-seven patients were identified, median age 47 years (range 28-76). Higher tumor stage and axillary lymph node dissection were associated with the receipt of RT (p = 0.023, p = 0.003 respectively). Baseline ROM was associated with both percent and absolute improvement in ROM (p = 0.007). Patients receiving no RT demonstrated the greatest mean percent improvement in ROM with PT (84%), compared to the pre-RT and d/a RT cohorts, which demonstrated a 63% and 40% improvement, respectively. In pairwise comparisons, patients in the no RT group and those in the PT pre-RT group both demonstrated a statistically greater improvement in percent change in ROM compared to patients receiving PT d/a RT (no RT 74% vs d/a RT 20%, p = 0.006; pre-RT 59% vs d/a RT 20%, p = 0.045). There was no difference in percent change in ROM between the no RT and pre-RT groups (p = 0.528). On univariate analysis, baseline worse ROM was associated with statistically worse percent change in ROM after PT (p = 0.008), no other baseline characteristics were associated with ROM after PT. When adjusting for baseline ROM, the no RT cohort continued to be associated with improvement in ROM compared to the PT d/a RT group (p = 0.024), while there was no difference in percent change in ROM between patients who received physical therapy pre-RT compared to no RT (p = 0.829). CONCLUSION Physical therapy is helpful in improving shoulder ROM at all stages of multimodality breast cancer treatment, however early initiation of PT prior to the start of RT may help maximize range of motion gains.
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Teaching Trainees to be Effective Mentors: A Needs-Based Assessment in Radiation Oncology. Int J Radiat Oncol Biol Phys 2023; 117:S114. [PMID: 37784298 DOI: 10.1016/j.ijrobp.2023.06.444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Mentorship plays a critical role in the training and career development of medical trainees. Teaching-the-teacher workshops for residents translate to higher long-term job satisfaction and improved patient communication skills. Further, near-peer mentorship has been associated with increased job satisfaction and patient care experience. Resident-as-mentors can add benefit to the mentorship networks of students, particularly in resource-limited environments, while benefiting residents' own mentorship relations and career satisfaction. We hypothesized that residents would desire to be a mentor, but would lack specific skills needed for effective mentoring of students in radiation oncology. MATERIALS/METHODS A multi-institution, cross-sectional study was conducted among residents in the Radiation Oncology Education Collaborative Study Group (ROECSG) Graduate Medical Education working group from 06/2022-10/2022. Participants completed the Mentorship Competency Assessment (MCA), a validated 26-item questionnaire, scored on a Likert scale from 0-7 (0: most unprepared with mentorship skill, 7: most prepared with mentorship skill). The primary endpoint was the average score in individual mentorship skills among participants. Kruskal-Wallis test assessed associations between total MCA score (range 0-182) and demographics. RESULTS A total of 36 of 39 participants (92% response rate) responded. A majority were male (58%), from a residency size >10 (75%), and P Gy-2/3 (52%). Most had no formal training in teaching (86%) or mentorship (89%). Many believed they would be a good mentor to students on a rotation (89%), but most felt they would benefit from a formal mentorship program (92%). From the MCA, the mentorship skills residents felt most unprepared for were: coordinating effectively with other mentors (3.4/7), helping mentees acquire resources (3.6/7), negotiating a path to professional independence with mentees (3.6/7), helping mentees network effectively (3.7/7), and working with mentees to set clear expectations of the mentoring relationship (3.9/7). The mentorship skills residents felt most prepared for were: acknowledging mentees' professional contributions (5.6/7), establishing a relationship based on trust (5.6/7), active listening (5.5/7), building mentees' confidence (4.9/7), and working effectively with mentees with personal backgrounds differing from one's own (4.8/7). Higher MCA scores were associated with former training in mentorship (p = 0.0143), and a trend for former training in teaching (p = 0.0525), but was not associated with sex (p = 0.5986), residency size (p = 0.1415), or P Gy-year (p = 0.9747). CONCLUSION Residents are interested in mentorship training and report unpreparedness in several important skills. Future work should focus on formal training and assessment of mentoring skills for residents.
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TEAMRO: TEAching Mentorship in Radiation Oncology, a Multicenter Prospective Phase 2 Intervention Study on Teaching Mentorship Skills to Residents Working with Medical Students. Int J Radiat Oncol Biol Phys 2023; 117:e541-e542. [PMID: 37785673 DOI: 10.1016/j.ijrobp.2023.06.1836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) While formal curriculum on resident teaching have been associated with improved career growth and sustained positive impact on patient care, mentorship skills are rarely taught in academic medicine. We hypothesized that a formalized resident mentorship curriculum coupled with a near-peer resident-medical student mentoring program would improve resident career growth. MATERIALS/METHODS A multi-institutional, prospective, phase 2 intervention study, approved by each participating center's institutional review board, was conducted from 4/2022-10/2022 among interested residents in the Radiation Oncology Education Collaborative Study Group Graduate Medical Education. Intervention included: 1) a 4-week mentorship curriculum (utilizing a Six Steps approach) composed of self-guided readings, didactic lecture, and 30-minute faculty check-in, and 2) a formalized 1:1 resident-medical student mentorship program during an existing radiation oncology sub-internship with weekly meetings. Resident participants completed the Mentorship Competency Assessment (MCA), a 26-item validated survey on mentorship skills in medicine scored from 0 (most unprepared) to 7 (most prepared) before and after the intervention. The primary endpoint was average change in MCA skill from pre- to post-intervention survey, with score ranges from -7 (a decrease in 7 points) to +7 (an increase of 7 points). RESULTS A total of 8 residents participated and all completed pre- and post-intervention surveys. Most residents were PGY-4/5 (75%), from programs with >10 residents (68%), and did not have prior training in teaching (88%) or mentorship (88%). Residents met students on average twice weekly (range 1-3) for an average of 2 hours a week (range 1-5). After the program, most residents felt confident in being a future mentor to students (100%), their overall well-being was positively impacted (63%), and their mentorship relationships were positively impacted (50%). All 26 mentorship skills increased on MCA after intervention (average +1.3/7 per skill). Skills that showed greatest improvement were helping mentees network effectively (+2.6/7), acquire resources (+2.1/7), negotiate a path to professional independence (+2.0/7), set career goals (+1.8/7), and balance work and personal life (+1.7/7). Skills that showed least improvement were establishing a relationship based on trust (+0.4/7), identifying and accommodating different communication styles (+0.6/7), providing constructive feedback (+0.7/7), and aligning mentor-mentee expectations (+0.8/7). CONCLUSION The formalized mentorship program improved mentorship skills among residents, translating to increased satisfaction in residents' own mentorship relations and overall well-being. Further studies are needed to assess the sustainability of these skills, as well as impact on career growth and satisfaction.
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Automated Sarcopenia Assessment and Outcomes in Head and Neck Cancer with Deep Learning Analysis of Cervical Neck Skeletal Muscle. Int J Radiat Oncol Biol Phys 2023; 117:e623. [PMID: 37785866 DOI: 10.1016/j.ijrobp.2023.06.2009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Sarcopenia is an established prognostic factor in patients diagnosed with head and neck cancers (HNC), typically measured by the skeletal muscle index (SMI) from abdominal muscle mass at L3. While sarcopenia assessment could inform HNC management, it remains impractical, time- and labor-intensive, and operator-dependent. To overcome these challenges, we developed an automated deep learning (DL) platform to calculate SMI at L3 by quantifying cross-sectional cervical skeletal muscle area (SMA) at C3 through auto-segmentation, externally validated it, and evaluated associations with clinical outcomes. MATERIALS/METHODS Eight hundred twenty-one patients diagnosed with HNC from multiple institutes from 1999-2013, treated with definitive chemoradiation with baseline pre-treatment CT scans, were included for model development (335 training, 96 tuning) and for independent testing (48 internal, and 342 external). Ground truth single-slice segmentations of SM at the mid-C3 vertebral level were manually annotated by radiation oncologists using an established protocol. A multi-stage DL pipeline was developed, with a 2D DenseNet to select the middle slice of C3 section and a 2D UNet to segment the SM, from which SMA was calculated. The model was evaluated using the Dice Similarity Coefficient (DC) for the internal test set, and human acceptability testing on the external test set was performed by two radiation oncologists not involved in annotations. SMI was calculated from C3 SMA based on prior literature, and sarcopenia was defined by an established, sex-specific SMI cutoff. Sarcopenia associations with overall survival (OS) and toxicities were assessed on the external dataset with Cox and logistic multivariable regressions, as indicated. RESULTS Model DC on the internal test set as 0.90 [95% CI: 0.90-0.91], with an intra-class coefficient of 0.96 for SMA. Human acceptability testing showed a pass rate of 94.4%. Of the 342 patients in the clinical analysis, 261 (76.3%) patients had sarcopenia. Five-year survival was 84.4% in patients without sarcopenia vs 73.1% in patients with sarcopenia (HR 2.21, p = 0.028) (median f/u: 44 mo (IQR: 25 - 66 mo)). On multivariable regression, sarcopenia (HR 2.06, p = 0.037), ACE-27 score 2+ (HR 2.25, p = 0.001), non-oropharynx diagnosis (HR 3.96, p<0.001), and T3-4 stage (HR 2.37, p<0.001) were associated with worse OS. Sarcopenia was associated with longer PEG tube duration on multivariable analysis (HR 1.59, p = 0.003), along with ACE-27 score (HR 1.20, p = 0.012) and non-oropharynx primary site (HR 1.46, p = 0.034). Sarcopenia was associated with higher risk of having PEG tube at last follow up (OR 2.25, p = 0.046). An observed increase in risk of hospitalization <3 months after RT was non-significant (OR 2.18, p = 0.117). CONCLUSION We developed and externally validated a fully-automated platform for sarcopenia assessment that can be used on routine HNC imaging. This algorithm is positioned for prospective testing to determine if use will inform HNC management.
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PfMORC protein regulates chromatin accessibility and transcriptional repression in the human malaria parasite, P. falciparum. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.11.557253. [PMID: 37745554 PMCID: PMC10515874 DOI: 10.1101/2023.09.11.557253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
The environmental challenges the human malaria parasite, Plasmodium falciparum, faces during its progression into its various lifecycle stages warrant the use of effective and highly regulated access to chromatin for transcriptional regulation. Microrchidia (MORC) proteins have been implicated in DNA compaction and gene silencing across plant and animal kingdoms. Accumulating evidence has shed light into the role MORC protein plays as a transcriptional switch in apicomplexan parasites. In this study, using CRISPR/Cas9 genome editing tool along with complementary molecular and genomics approaches, we demonstrate that PfMORC not only modulates chromatin structure and heterochromatin formation throughout the parasite erythrocytic cycle, but is also essential to the parasite survival. Chromatin immunoprecipitation followed by deep sequencing (ChIP-seq) experiments suggest that PfMORC binds to not only sub-telomeric regions and genes involved in antigenic variation but is also most likely a key modulator of stage transition. Protein knockdown experiments followed by chromatin conformation capture (Hi-C) studies indicate that downregulation of PfMORC induces the collapse of the parasite heterochromatin structure leading to its death. All together these findings confirm that PfMORC plays a crucial role in chromatin structure and gene regulation, validating this factor as a strong candidate for novel antimalarial strategies.
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Association of Baseline Symptom Burden and Survival among Patients with Brain Metastases at a Tertiary Cancer Center. Int J Radiat Oncol Biol Phys 2022. [DOI: 10.1016/j.ijrobp.2022.07.798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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The Carbon Footprint of Radiation Oncology on Climate Change: A Model in Early-Stage Breast Cancer. Int J Radiat Oncol Biol Phys 2022. [DOI: 10.1016/j.ijrobp.2022.07.582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Five decades of risk perception measurements of tobacco use: a review of literature. CARDIOMETRY 2021. [DOI: 10.18137/cardiometry.2021.20.8899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Perceptions of risk are beliefs about the likelihood of damage orloss. People make subjective judgments regarding the intensityand features of a danger. Smoking start and continuation areinfluenced by risk perception. Risk perception of tobacco useor smoking has always been controversial. Few studies foundthat risk perception is overestimated by smokers and tobaccousers, while other studies found that smokers underestimatethe risk of smoking. It has been observed that different authorshave been using different approaches to measure the risk perceptionof tobacco use. The present literature review is an ontologicalexploration of the process of calculating this constructand determining which method gives more holistic and robustinformation. A literature survey was carried out to understanddifferent ways in which risk perception can be measured. Fifty-seven studies were identified from 1970 to 2020 in which riskperception was calculated for any form of tobacco use. Theliterature review found that the researchers used two practicalapproaches to measure risk perception. In the first approach,the researchers tried to measure only the health risks of tobaccouse, and in the second, multiple dimensions of tobaccouse were measured. Most commonly perceived addictionand then the social risk of tobacco use was accessed. Thoughrecent literature is dominated by an approach where a singledimension, i.e., perceived health risk of tobacco use, is mostcommonly access, it is inferring from the available literature thattools that access multiple sizes of the perceived risk of tobaccouse give more comprehensive and robust information aboutthat construct which can be used further to create tobacco useprevention intervention.
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Fractionated Proton Beam Radiation Therapy and Hearing Preservation for Vestibular Schwannoma: Preliminary Analysis of a Prospective Phase 2 Clinical Trial. Int J Radiat Oncol Biol Phys 2021. [DOI: 10.1016/j.ijrobp.2021.07.233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Quantitative Evaluation of Normal Lung Density Changes in Non-Small Cell Lung Cancer Patients Treated With Radiotherapy and PD-1 Immune Checkpoint Inhibitors. Int J Radiat Oncol Biol Phys 2021. [DOI: 10.1016/j.ijrobp.2021.07.564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Mixed Methods Evaluation of a Targeted One-Week Virtual Radiation Oncology Intensive Shadowing Experience for Medical Students Underrepresented in Medicine: Mentor's Perspective. Int J Radiat Oncol Biol Phys 2021. [DOI: 10.1016/j.ijrobp.2021.07.094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Clinical Validation of Deep Learning Algorithms for Lung Cancer Radiotherapy Targeting. Int J Radiat Oncol Biol Phys 2021. [DOI: 10.1016/j.ijrobp.2021.07.167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Design and Multicenter Clinical Validation of a 3-Dimensionally Printed Nasopharyngeal Swab for SARS-CoV-2 Testing. JAMA Otolaryngol Head Neck Surg 2021; 147:418-425. [PMID: 33599684 DOI: 10.1001/jamaoto.2020.5680] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance Three-dimensionally printed nasopharyngeal swabs (3DP swabs) have been used to mitigate swab shortages during the coronavirus disease 2019 (COVID-19) pandemic. Clinical validation for diagnostic accuracy and consistency, as well as patient acceptability, is crucial to evaluate the swab's performance. Objective To determine the accuracy and acceptability of the 3DP swab for identifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Design, Setting, and Participants A diagnostic study was conducted from May to July 2020 at 2 tertiary care centers in Singapore with different reference swabs (FLOQSwab [COPAN Diagnostics] or Dacron swab [Deltalab]) and swab processing techniques (wet or dry) to evaluate the performance of the 3DP swab compared with traditional, standard-of-care nasopharyngeal swabs used in health care institutions. The participants were patients with COVID-19 in the first 2 weeks of illness and controls with acute respiratory illness with negative test results for SARS-CoV-2. Paired nasopharyngeal swabs were obtained from the same nostril and tested for SARS-CoV-2 by reverse-transcriptase polymerase chain reaction. The sequence of swabs was randomized based on odd and even participant numbers. Main Outcomes and Measures Primary outcome measures were overall agreement (OA), positive percentage agreement (PPA), and negative percentage agreement of the 3DP swab compared with reference swabs. Secondary outcome measures were the correlation of cycle threshold (Ct) values of both swabs. Results The mean (SD) age of participants was 45.4 (13.1) years, and most participants were men (87 of 89 [97.8%]), in keeping with the epidemiology of the COVID-19 pandemic in Singapore. A total of 79 patients with COVID-19 and 10 controls were recruited. Among the patients with COVID-19, the overall agreement and PPA of the 3DP swab was 91.1% and 93.5%, respectively, compared with reference swabs. The PPA was 100% for patients with COVID-19 who were tested within the first week of illness. All controls tested negative. The reverse-transcriptase polymerase chain reaction Ct values for the ORF1ab and E-gene targets showed a strong correlation (intraclass correlations coefficient, 0.869-0.920) between the 3DP and reference swab on independent testing at each institution despite differences in sample processing. Discordant results for both gene targets were observed only at high Ct values. Conclusions and Relevance In this diagnostic study of 79 patients with COVID-19 and 10 controls, the 3DP swab performed accurately and consistently across health care institutions and could help mitigate strained resources in the escalating COVID-19 pandemic.
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BRK phosphorylates SMAD4 for proteasomal degradation and inhibits tumor suppressor FRK to control SNAIL, SLUG, and metastatic potential. SCIENCE ADVANCES 2019; 5:eaaw3113. [PMID: 31681835 PMCID: PMC6810434 DOI: 10.1126/sciadv.aaw3113] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 09/13/2019] [Indexed: 05/06/2023]
Abstract
The tumor-suppressing function of SMAD4 is frequently subverted during mammary tumorigenesis, leading to cancer growth, invasion, and metastasis. A long-standing concept is that SMAD4 is not regulated by phosphorylation but ubiquitination. Our search for signaling pathways regulated by breast tumor kinase (BRK), a nonreceptor protein tyrosine kinase that is up-regulated in ~80% of invasive ductal breast tumors, led us to find that BRK competitively binds and phosphorylates SMAD4 and regulates transforming growth factor-β/SMAD4 signaling pathway. A constitutively active BRK (BRK-Y447F) phosphorylates SMAD4, resulting in its recognition by the ubiquitin-proteasome system, which accelerates SMAD4 degradation. Activated BRK-mediated degradation of SMAD4 is associated with the repression of tumor suppressor gene FRK and increased expression of mesenchymal markers, SNAIL, and SLUG. Thus, our data suggest that combination therapies targeting activated BRK signaling may have synergized the benefits in the treatment of SMAD4 repressed cancers.
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Measurements of ionization states in warm dense aluminum with betatron radiation. Phys Rev E 2017; 95:053208. [PMID: 28618605 DOI: 10.1103/physreve.95.053208] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Indexed: 11/07/2022]
Abstract
Time-resolved measurements of the ionization states of warm dense aluminum via K-shell absorption spectroscopy are demonstrated using betatron radiation generated from laser wakefield acceleration as a probe. The warm dense aluminum is generated by irradiating a free-standing nanofoil with a femtosecond optical laser pulse and was heated to an electron temperature of ∼20-25 eV at a close-to-solid mass density. Absorption dips in the transmitted x-ray spectrum due to the Al^{4+} and Al^{5+} ions are clearly seen during the experiments. The measured absorption spectra are compared to simulations with various ionization potential depression models, including the commonly used Stewart-Pyatt model and an alternative modified Ecker-Kröll model. The observed absorption spectra are in approximate agreement with these models, though indicating a slightly higher state of ionization and closer agreement for simulations with the modified Ecker-Kröll model.
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Risk Factors Associated With Interval Time Between Breast Cancer Diagnosis and Development of Brain Metastasis. Int J Radiat Oncol Biol Phys 2016. [DOI: 10.1016/j.ijrobp.2016.06.861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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A differently managed Spleen Injury. INTERNATIONAL JOURNAL OF RECENT SURGICAL AND MEDICAL SCIENCES 2016. [DOI: 10.5005/jp-journals-10053-0013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Abstract
Introduction: Treatment of symptomatic splenic injury after more than 1 month of the trauma is not very specific. Moreover, here, we are reporting such a case where the patient was treated laparoscopically salvaging the spleen.
Case report: A 26-year-old young male presented with persistent pain in the left upper abdomen and back, following a splenic injury while playing football 1 month ago. Abdominal ultrasound showed subcapsular hematoma with intact hilum. Contrast-enhanced computed tomography of whole abdomen showed large subcapsular hematoma grade III with intact hilar vessels. In view of persistent pain and discomfort, which debilitated and restrained him from daily as well as professional activity, even after 1 month of trauma, the patient was planned for diagnostic laparoscopy and proceed, which revealed hemoperitoneum and was aspirated. Omentum was separated from splenic capsule, breech in the capsule was extended, and hematoma was sucked out. The drain was removed on 4th postoperative day after ultrasound to exclude any fresh hemorrhage. The patient soon started daily activity and resumed his job after 15 days.
Conclusion: Surgical intervention in a hemodynamically stable splenic-injury patient may sometimes be required depending upon the condition and symptoms of the patient.
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Association of CYP2C19, CYP3A5 and GPIIb/IIIa gene polymorphisms with Aspirin and Clopidogrel Resistance in a cohort of Indian patients with Coronary Artery Disease. Int J Lab Hematol 2015; 37:809-18. [PMID: 26264906 DOI: 10.1111/ijlh.12416] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 07/13/2015] [Indexed: 12/27/2022]
Abstract
INTRODUCTION Dual antiplatelet therapy with clopidogrel and aspirin is the current standard of care in the management of patients with coronary artery disease (CAD) and acute coronary syndrome (ACS). The variability in response to these antiplatelet agents may be due to the underlying genetic diversity. This study was designed to determine the resistance to aspirin and clopidogrel in Indian patients and to look for correlation, if any, with selected polymorphisms. METHODS Platelet function testing by light transmission aggregometry was performed on 72 patients with CAD/ACS who were stable on dual antiplatelet therapy (clopidogrel 75 mg OD and aspirin 150 mg OD) along with 72 controls. Aspirin resistance was considered as mean platelet aggregation ≥ 70% with 10 μm ADP and ≥ 20% with 0.75 mm arachidonic acid. Clopidogrel resistance was defined as <10% decrease from the baseline in platelet aggregation in response to ADP 10 μm and semi-response as <30% decrease from the baseline. Polymorphisms CYP2C19*2, *3, CYP3A5*3 and PLA1/A2 were genotyped. RESULTS We found 51.4% patients with inadequate response to clopidogrel (1.4% resistant and 50% semi-responders) and 5.5% patients semi-responders to aspirin, none being completely resistant. The genotype and allele frequencies of CYP2C19*2 and PLA1/A2 gene polymorphisms were significantly different between clopidogrel semi-responders and responders. Carriers of CYP2C19*2 and CYP3A5*3 showed diminished inhibition of platelet aggregation. No significant correlation was found between coronary events, type of coronary intervention with clopidogrel nonresponsiveness. CONCLUSION Unlike aspirin, a high proportion of partial responders to clopidogrel were identified. In an interim analysis on 72 Indian patients, a significant association was found between CYP2C19*2 and PLA1/A2 in clopidogrel semi-responders.
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Laser wakefield generated X-ray probe for femtosecond time-resolved measurements of ionization states of warm dense aluminum. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:123106. [PMID: 24387419 DOI: 10.1063/1.4842237] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We have developed a laser wakefield generated X-ray probe to directly measure the temporal evolution of the ionization states in warm dense aluminum by means of absorption spectroscopy. As a promising alternative to the free electron excited X-ray sources, Betatron X-ray radiation, with femtosecond pulse duration, provides a new technique to diagnose femtosecond to picosecond transitions in the atomic structure. The X-ray probe system consists of an adjustable Kirkpatrick-Baez (KB) microscope for focusing the Betatron emission to a small probe spot on the sample being measured, and a flat Potassium Acid Phthalate Bragg crystal spectrometer to measure the transmitted X-ray spectrum in the region of the aluminum K-edge absorption lines. An X-ray focal spot size of around 50 μm was achieved after reflection from the platinum-coated 10-cm-long KB microscope mirrors. Shot to shot positioning stability of the Betatron radiation was measured resulting in an rms shot to shot variation in spatial pointing on the sample of 16 μm. The entire probe setup had a spectral resolution of ~1.5 eV, a detection bandwidth of ~24 eV, and an overall photon throughput efficiency of the order of 10(-5). Approximately 10 photons were detected by the X-ray CCD per laser shot within the spectrally resolved detection band. Thus, it is expected that hundreds of shots will be required per absorption spectrum to clearly observe the K-shell absorption features expected from the ionization states of the warm dense aluminum.
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Elevated mean neutrophil volume+CRP is a highly sensitive and specific predictor of neonatal sepsis. Int J Lab Hematol 2013; 36:e11-4. [PMID: 23795566 DOI: 10.1111/ijlh.12120] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Rugae patterns as an adjunct to sex differentiation in forensic identification. THE JOURNAL OF FORENSIC ODONTO-STOMATOLOGY 2011; 29:14-19. [PMID: 21841264 PMCID: PMC5734836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
It is widely acknowledged that in some forensic situations there are limitations to identification of the deceased by fingerprints, DNA and dental records. Palatal rugae pattern of an individual may be considered as a useful adjunct for sex determination for identification purposes. The aim of this study was to identify and compare the rugae pattern in Indian males and females, as an additional method of differentiating the sexes in various postmortem scenarios. Dental stone casts of 120 Indians: 60 males and 60 females were obtained. The method of identification of rugae patterns was that of Thomas and Kotze (1983) and Kapali et al (1997) which includes the number, length, shape and unification of rugae. Our study revealed no significant difference in the total number or various length measurements of rugae between the two sexes which conforms to previous results. However, in terms of the different types of rugae shape, the converging type of rugae were statistically greater in number in females whilst the circular type of rugae were statistically greater in number in males, which contrasts with earlier studies. The use of logistic regression analysis (LRA) enabled highly accurate sex prediction (>99%) when all the rugae shapes were analyzed. It may be concluded that rugae pattern through the use of LRA can be an additional method of differentiation between the Indian male and female and assist with the identification process in conjunction with other methods such as visual, fingerprints and dental characteristics in forensic sciences.
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Effects of TGF-beta3 and preculture period of osteogenic cells on the chondrogenic differentiation of rabbit marrow mesenchymal stem cells encapsulated in a bilayered hydrogel composite. Acta Biomater 2010; 6:2920-31. [PMID: 20197126 DOI: 10.1016/j.actbio.2010.02.046] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 02/23/2010] [Accepted: 02/24/2010] [Indexed: 12/17/2022]
Abstract
In this work, injectable, biodegradable hydrogel composites of crosslinked oligo(poly(ethylene glycol) fumarate) and gelatin microparticles (MPs) were used to fabricate a bilayered osteochondral construct. Rabbit marrow mesenchymal stem cells (MSCs) were encapsulated with transforming growth factor-beta3 (TGF-beta3)-loaded MPs in the chondrogenic layer and cocultured with cells of different periods of osteogenic preculture (0, 3, 6 and 12 days) in the osteogenic layer to investigate the effects of TGF-beta3 delivery and coculture on the proliferation and differentiation of cells in both layers. The results showed that, in the chondrogenic layer, TGF-beta3 significantly stimulated chondrogenic differentiation of MSCs. In addition, cells of various osteogenic preculture periods in the osteogenic layer, along with TGF-beta3, enhanced gene expression for MSC chondrogenic markers to different extents. In the osteogenic layer, cells maintained their alkaline phosphatase activity during the coculture; however, mineralization was delayed by the presence of TGF-beta3. Overall, this study demonstrated the fabrication of bilayered hydrogel composites which mimic the structure and function of osteochondral tissue, along with the application of these composites as cell and growth factor carriers, while illustrating that encapsulated cells of different degrees of osteogenic differentiation can significantly influence the chondrogenic differentiation of cocultured progenitor cells in both the presence and absence of chondrogenic growth factors.
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Characterization of endotoxin and 3-hydroxy fatty acid levels in air and settled dust from commercial aircraft cabins. INDOOR AIR 2003; 13:166-173. [PMID: 12756010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Endotoxin was measured in air and dust samples collected during four commercial aircraft flights. Samples were analyzed for endotoxin biological activity using the Limulus assay. 3-hydroxy fatty acids (3-OH FA) of carbon chain lengths C10:0-C18:0 were determined in dust by gas chromatography-ion trap tandem mass spectrometry. The geometric mean (geometric standard deviation) endotoxin air level was 1.5 EU/m3 (1.9, n = 28); however, significant differences were found by flight within aircraft type. Mean endotoxin levels were significantly higher in carpet dust than in seat dust (140 +/- 81 vs. 51 +/- 25 EU/mg dust, n = 32 each, P < 0.001). Airborne endotoxin levels were not significantly related to either carpet or seat dust endotoxin levels. Mean 3-OH FA levels were significantly higher in carpet dust than in seat dust for C10:2, C12:0, and C14:0 (P < 0.001 for each), while the mean level of C16:0 was significantly higher in seat dust than in carpet dust (P < 0.01). Carpet dust endotoxin was significantly, but moderately, correlated with 3-OH-C12:0 and 3-OH-C14:0 (Pearson r = 0.52 and 0.48, respectively), while correlation of seat dust endotoxin with individual 3-OH FAs depended on the test statistic used. Mean endotoxin potency was significantly higher for carpet dust than for seat dust (6.3 +/- 3.0 vs. 3.0 +/- 1.4 EU/pmol LPS, P < 0.0001). Mean endotoxin levels in the air and dust of commercial aircraft cabins were generally higher than mean levels reported in homes and office buildings. These results suggest that exposure route and dust source are important considerations when relating endotoxin exposure to specific health outcomes.
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Demonstration of pilot-scale pervaporation systems for volatile organic compound removal from a surfactant enhanced aquifer remediation fluid II. Hollow fiber membrane modules. ACTA ACUST UNITED AC 2001. [DOI: 10.1002/ep.670200117] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Investigation of the concentration of bacteria and their cell envelope components in indoor air in two elementary schools. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2000; 50:1957-1967. [PMID: 11111340 DOI: 10.1080/10473289.2000.10464225] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Bacterial cell envelope components are widely distributed in airborne dust, where they act as inflammatory agents causing respiratory symptoms. Measurements of these agents and other environmental factors are assessed in two elementary schools in a southeastern city in the United States. Muramic acid (MA) was used as a marker for bacterial peptidoglycan (PG), and 3-hydroxy fatty acids (3-OH FAs) were used as markers for Gram-negative bacterial lipopolysaccharide (LPS). Culturable bacteria were collected using an Andersen sampler with three different culture media. In addition, temperature (T), relative humidity (RH), and CO2 were continuously monitored. Concentrations of airborne MA and 3-OH FAs were correlated with total suspended particulate (TSP) levels. Outdoor MA (mean = 0.78-1.15 ng/m3) and 3-OH FA levels (mean = 2.19-2.18 ng/m3) were similar at the two schools. Indoor concentrations of airborne MA and 3-OH FAs differed significantly between schools (MA: 1.44 vs. 2.84 ng/m3; 3-OH FAs: 2.96 vs. 4.57 ng/m3). Although indoor MA levels were low, they were significantly related to teachers' perception of the severity of indoor air quality (IAQ) problems in their classrooms. Concentrations of CO2 correlated significantly with all bacteria measurements. Because CO2 levels were related to the number of occupants and the ventilation rates, these findings are consistent with the hypothesis that the children and teachers are sources of bacterial contamination. Many culturable bacteria present in indoor air are opportunistic organisms that can be infectious for compromised individuals, while both culturable and nonculturable bacterial remnants act as environmental toxins for both healthy and compromised individuals. Measuring the "total bacteria load" would be most accurate in assessing the biotoxicity of indoor air. Chemical analysis of MA and 3-OH FAs, when coupled with the conventional culture method, provides complementary information for assessing biocontamination of indoor air.
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Abstract
The in vitro potency of house dust to induce cytokine response in A549 lung epithelial cells was studied. Dusts collected from carpet, bed, shelf and floor of a villa and an apartment by vacuuming were found to trigger the production of interleukin-8 (IL-8) and interleukin-6 (IL-6) in a dose-dependent manner, and the interleukin production was several-fold higher than of swine dust (used as a positive control). The IL-8 and IL-6 production of pure Escherichia coli lipopolysaccharide was significantly lower than of the dusts and a peptidoglycan-polysaccharide complex did not show any stimulatory effect at all. The lipopolysaccharide and peptidoglycan contents of the samples were determined by gas chromatography-tandem mass spectrometry analysis of, respectively, 3-hydroxy fatty acids and muramic acid; in addition, ergosterol was monitored for fungal biomass. The inflammatory properties of house dust upon inhalation may be reflected in its high potency to induce cytokine response in lung epithelial cells.
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Use of quadrupole GC-MS and ion trap GC-MS-MS for determining 3-hydroxy fatty acids in settled house dust: relation to endotoxin activity. JOURNAL OF ENVIRONMENTAL MONITORING : JEM 1999; 1:163-8. [PMID: 11529095 DOI: 10.1039/a809019j] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gas chromatography-mass spectrometry (GC-MS) using a quadrupole instrument and GC-tandem MS (GC-MS-MS) using an ion trap instrument were applied to determine 3-hydroxy fatty acids (3-OH FAs) with 10-18 carbon chain lengths, specific components of the endotoxin (lipopolysaccharide, LPS) of Gram-negative bacteria, in 30 house dust samples. The two methods provided similar detection sensitivity for methyl ester/trimethylsilyl derivatives of the 3-OH FAs and allowed these acids to be distinguished from co-eluting 2-OH FA derivatives. The correlation coefficients between endotoxin activity (Limulus test) and the combined amounts of 3-OH C10, 3-OH C12, and 3-OH C14 were 0.60 and 0.61 when using GC-MS and GC-MS-MS, respectively. The superior selectivity of GC-MS-MS was illustrated in analyses of sub-milligram amounts of dust, where the chromatograms achieved by GC-MS were difficult to interpret due to a high background and several closely eluting compounds. GC-MS-MS is therefore preferable to GC-MS for determining 3-OH FAs in minute (sub-milligram) amounts of dust.
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Total and viable airborne bacterial load in two different agricultural environments using gas chromatography-tandem mass spectrometry and culture: a prototype study. AMERICAN INDUSTRIAL HYGIENE ASSOCIATION JOURNAL 1998; 59:524-31. [PMID: 9725931 DOI: 10.1080/15428119891010695] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Airborne exposure to bacterial components found in agricultural environments can lead to pulmonary inflammation. Total (viable and nonviable) bacterial load was monitored in a stable and a dairy by a new approach, gas chromatography-tandem mass spectrometry measurement of muramic acid, a component of gram positive and gram negative bacterial peptidoglycan. Also used to assess the gram negative bacterial load were 3-hydroxy fatty acids, markers of bacterial lipopolysaccharide. Culture, an established procedure for assessing the viable bacterial portion of airborne dust, served as a basis for comparison. The muramic acid and 3-hydroxy fatty acid concentrations (total C12:0, C14:0, and C16:0) showed a correlation with an R2 of 0.81. Dust and muramic acid levels also correlated. However, although relative muramic acid levels were lower in the stable than the dairy, colony forming units (CFU) were considerably higher in the stable. The total bacterial load (estimated from muramic acid values) for both the stable and dairy was also higher than would have been predicted from culture. These results suggest that nonculture based approaches and culture provide complementary but independent measurements of airborne biopollution.
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Quantification of ergosterol and 3-hydroxy fatty acids in settled house dust by gas chromatography-mass spectrometry: comparison with fungal culture and determination of endotoxin by a Limulus amebocyte lysate assay. Appl Environ Microbiol 1997; 63:2554-9. [PMID: 9212406 PMCID: PMC168553 DOI: 10.1128/aem.63.7.2554-2559.1997] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Ergosterol and 3-hydroxy fatty acids, chemical markers for fungal biomass and the endotoxin of gram-negative bacteria, respectively, may be useful in studies of health effects of organic dusts, including domestic house dust. This paper reports a method for the combined determination of ergosterol and 3-hydroxy fatty acids in a single dust sample and a comparison of these chemical biomarkers determined by gas chromatography-mass spectrometry with results from fungal culture and Limulus assay. Analyses of replicate house dust samples resulted in correlations of 0.91 (ergosterol in six replicates; P < 0.01) and 0.94 (3-hydroxy fatty acids in nine replicates; P < 0.001). The amounts of ergosterol (range, 2 to 16.5 ng/mg of dust) correlated with those of total culturable fungi (range, 6 to 1,400 CFU/mg of dust) in 17 samples, (r = 0.65; P < 0.005). The amounts of endotoxin (range, 11 to 243 endotoxin units/mg of dust) measured with a modified chromogenic Limulus assay correlated with those of lipopolysaccharide (LPS) determined from 3-hydroxy fatty acid analysis of 15 samples. The correlation coefficient depended on the chain lengths of 3-hydroxy acids used to compute the LPS content. The correlation was high (r = 0.88 +/- 0.01; P < 0.001) when fatty acid chains of 10 to 14 carbon atoms were included; the correlation was much lower when hydroxy acids of 16- or 18-carbon chains were included. In conclusion, the results of the described extraction and analysis procedure for ergosterol and 3-hydroxy fatty acids are reproducible, and the results can be correlated with fungal culture and endotoxin activity of organic dust samples.
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Use of gas chromatography-ion trap tandem mass spectrometry for the detection and characterization of microorganisms in complex samples. Mol Biotechnol 1997; 7:279-87. [PMID: 9219241 DOI: 10.1007/bf02740818] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Gas chromatography-mass spectrometry (GC-MS) can be applied to detect and characterize microorganisms in clinical and environmental samples, and microbial contaminants in biotechnological production cultures. With this approach, unique microbial monomeric compounds, known as chemical markers, are used as analytes. In the present article, two GC-MS-based techniques, viz. GC-ion trap tandem MS (GC-MS-MS) and conventional quadrupole GC-MS used in the selected ion monitoring mode, were compared regarding their ability to detect 3-hydroxy fatty acids, muramic acid, and ergosterol (markers for endotoxin, peptidoglycan, and fungal biomass, respectively) in complex matrices. When using GC-MS-MS, daughter ion spectra were obtained for all markers present in amounts close to the detection limit of the GC-MS. Ion-trap GC-MS-MS shows great promise as a chemical marker analysis technique for application in clinical diagnosis, occupational and public health care, and biotechnology.
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Exposure to bacteria in swine-house dust and acute inflammatory reactions in humans. Am J Respir Crit Care Med 1996; 154:1261-6. [PMID: 8912733 DOI: 10.1164/ajrccm.154.5.8912733] [Citation(s) in RCA: 109] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Inhalation of swine-house dust may cause an acute airway inflammatory condition (organic dust toxic syndrome). Thirty-eight healthy subjects were exposed to swine dust while weighing swine for 3 h. We studied the correlation between acute health effects and the inhaled bacterial exposure markers peptidoglycan (the main constituent of the cell walls of gram-positive bacteria, but also present in lesser amounts in gram-negative bacteria) and lipopolysaccharides (LPS; present only in gram-negative bacteria). LPS activity in airborne dust was measured with the Limulus amebocyte lysate assay (LPS(LAL)), and the total LPS was estimated from 3-hydroxy fatty acids, which were measured with gas chromatography-mass spectrometry (GC-MS) (LPS(GC-MS)). Peptidoglycan was estimated from muramic acid measured with GC-MS. The median (25th to 75th percentile) concentration of inhalable dust was 21 (16 to 25) mg/m3. LPS(LAL) was 1.2 (0.9 to 1.4) microg/m3; LPS(GC-MS) was 3.9 (2.5 to 4.9) microg/m3; and the peptidoglycan concentration in airborne dust was 6.5 (2.7 to 13) microg/m3. All exposure markers correlated significantly with an increase in serum interleukin-6. LPS(LAL) showed the highest correlation (r2 = 0.29) and total inhaled dust the lowest (r2 = 0.09). LPS(LAL) also correlated with symptoms and with an increase in bronchial responsiveness and decrease in vital capacity (VC). Peptidoglycan, but not LPS(LAL), correlated with an increase in the blood granulocyte concentration and in body temperature. The results suggest that several microbial agents in inhaled swine-house dust may contribute to acute systemic health effects.
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Determination of ergosterol in organic dust by gas chromatography-mass spectrometry. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1995; 666:77-84. [PMID: 7655624 DOI: 10.1016/0378-4347(94)00553-h] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A gas chromatographic-mass spectrometric method was developed for the determination of ergosterol in organic dust. Samples were hydrolyzed under alkaline conditions, and the hydrolysate was extracted, purified on a silica-gel column, and subjected to derivatization. The limit of detection of the trimethylsilyl ether derivative of ergosterol was approximately 10 pg and that of the tert.-butyldimethylsilyl ether derivative was approximately 20 pg (injected amounts). House dust contained 6-45 micrograms ergosterol/g and air from a pig barn contained 0.2-0.3 ng ergosterol/liter. The proposed method can be used as a complement or alternative to microscopy and culturing for measuring fungal biomass in air-borne organic dust.
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Analysis of the structure-activity relationships in the series of flavonoids. Pharmacol Res 1995. [DOI: 10.1016/1043-6618(95)87531-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
Trends in incidence and neonatal outcome following low Apgar scores (1 min Apgar score < 6) were prospectively studied during the years (1981, 1983, 1986 and 1988. The incidence of birth asphyxia was 7.6% of live births during the study period; it was 5.8% in 1981, increased to highest of 8.9% in 1986 with slight reduction to 7.2% in 1988. Birth weight distribution of asphyxiated babies and 1 min Apgar score < 3 (severe asphyxia) remained unchanged. A significant decline in neonatal mortality with asphyxia was noted from 46.0% to 28.4% during 1981 and 1988 respectively. Aetiological factors for asphyxia could be identified in nearly 90% of infants during 1988, and all but 2 of 12 factors studied registered significant differences from control non-asphyxiated group.
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Abstract
A unique polypeptide, called enhancing factor (EF), which enhances the binding of labeled epidermal growth factor (EGF) to cells, has been isolated. It has been purified to homogeneity from the acid-soluble proteins of mouse intestines. Earlier, EF was partially purified by two cycles of gel-permeation chromatography on Bio-Gel columns. We now report the final purification of EF on high-performance liquid chromatography (HPLC), using a reverse-phase column (mu Bondapak C18). The purity of the protein was confirmed when a single peak was obtained in HPLC. Also, a single protein band was obtained in SDS-PAGE. Purified EF has the same properties in vitro as those reported earlier for partially purified EF.
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