Safety vs price in the generic drug market: metformin

OBJECTIVES

Generic medications represent 90% of prescriptions in the US market and provide a tremendous financial benefit for patients. Recently, multiple generic drugs have been recalled due to the presence of carcinogens, predominantly N-nitrosodimethylamine (NDMA), including an extensive recall of extended-release (ER) metformin products in 2020.

STUDY DESIGN

Primary pharmaceutical quality testing and database analysis.

METHODS

We tested marketed metformin immediate-release (IR) and ER tablets from a wide sample of generic manufacturers for the presence of carcinogenic impurities NDMA and N,N-dimethylformamide (DMF). We examined the association of level of impurity with drug price and the impact of the 2020 FDA recalls on unit price and prescription fill rate.

RESULTS

Postrecall NDMA levels were significantly lower in metformin ER samples (standardized mean difference = -2.0; P = .01); however, we found continued presence of carcinogens above the FDA threshold in 2 of 30 IR samples (6.67%). Overall, the presence of contaminant levels was not significantly associated with price for either IR (NDMA: R2 = 0.142; P = .981; DMF: R2 = 0.382; P = .436) or ER (NDMA: R2 = 0.124; P = .142; DMF: R2 = 0.199; P = .073) samples. Despite recalls, metformin ER prescription fills increased by 8.9% while unit price decreased by 19.61% (P < .05).

CONCLUSIONS

Recalls of metformin ER medications were effective in lowering NDMA levels below the FDA threshold; however, some samples of generic metformin still contained carcinogens even after FDA-announced recalls. The absence of any correlation with price indicates that potentially safer products are available on the market for the same price as poorer-quality products.

P-026 SMALL BITE CLOSURE IN EMERGENCY LAPAROTOMY; A RETROSPECTIVE COHORT ANALYSIS

Aims

To investigate the outcomes of the implementation of small bite closure in emergency laparotomy

Methods

A retrospective comparative cohort analysis was performed from Northumbria NHS Trust (United Kingdon) surgical database from 2017 to 2021. All cases of emergency laparotomy were included. Cases of open appendicectomy were excluded. Small bite closure was performed by a standardised technique with slowly absorbable sutures. A matched cohort of cases who were closed with mass closure were used for comparison.

Results

262 cases of emergency small bites closure were included, and 247 cases of emergency mass closure. There were comparative age, sex and ASA grade in each group. There was no significant variation in the types of procedure performed.

In the small bites closure group, there were 8 cases of superficial dehiscence (3%), 4 cases of deep dehiscence (1.5%) and 16 wound infections (6%). The mean post operative stay was 10 days (2 to 74). The 30 days mortality was 18 cases (7%) and 40 cases overall (15%).

In the mass closure group, there were 6 cases of superficial dehiscence (2%), 6 cases of deep dehiscence (2%) and 23 wound infections (9%). The mean post operative stay was 14 days (3 to 65). The 30 day mortality was 34 cases (14%) and 65 cases overall (26%).

Conclusion

Small bites closure shows comparative results to mass closure in the emergency setting in post operative outcomes. Small bites closure is safe and feasible in the emergency setting.

A modified Delphi process to establish research priorities in hernia surgery

BACKGROUND

Abdominal wall hernia repair is one of the most commonly performed surgical procedures worldwide, yet despite this, there remains a lack of high-quality evidence to support best management. The aim of the study was to use a modified Delphi process to determine future research priorities in this field.

METHODS

Stakeholders were invited by email, using British Hernia Society membership details or Twitter, to submit individual research questions via an online survey. In addition, questions obtained from a patient focus group (PFG) were collated to form Phase I. Two rounds of prioritization by stakeholders (phases II and III) were then completed to determine a final list of research questions. All questions were analyzed on an anonymized basis.

RESULTS

A total of 266 questions, 19 from the PFG, were submitted by 113 stakeholders in Phase I. Of these, 64 questions were taken forward for prioritization in Phase II, which was completed by 107 stakeholders. Following Phase II analysis, 97 stakeholders prioritized 36 questions in Phase III. This resulted in a final list of 14 research questions, 3 of which were from the PFG. Stakeholders included patients and healthcare professionals (consultant surgeons, trainee surgeons and other multidisciplinary members) from over 27 countries during the 3 phases.

CONCLUSION

The study has identified 14 key research priorities pertaining to abdominal wall hernia surgery. Uniquely, these priorities have been determined from participation by both healthcare professionals and patients. These priorities should now be addressed by well-designed, high-quality international collaborative research.

Management of the uncomplicated primary inguinal hernia in 2019: the practice amongst members of the British Hernia Society

INTRODUCTION

The aim of this study was to survey the current practice of UK-based hernia surgeons in elective inguinal hernia repair.

MATERIALS AND METHODS

A questionnaire was created using SurveyMonkey™ and sent electronically to registered members of the British Hernia Society.

RESULTS

A total of 368 responses were obtained (a response rate of 55%); 83% were consultant surgeons, 91% were male and 91% stated that they had an interest in laparoscopic surgery. For an uncomplicated inguinal hernia in a male patient, 60% would perform an open Lichtenstein repair, 20% trans-abdominal pre-peritoneal repair and 20% totally extra-peritoneal repair. In a female patient, 54% would perform an open Lichtenstein repair, 25% trans-abdominal pre-peritoneal repair and 21% totally extra-peritoneal repair. 90% always use mesh in inguinal hernia repair. 93% of surgeons rarely or never perform a tissue repair.

CONCLUSIONS

Despite recent controversy, UK surgeons support the use of mesh in the repair of inguinal hernias with an open Lichtenstein repair being the most common choice. There has only been a modest increase in the use of laparoscopic surgery over the past 20 years.

Umbilical Ablation During Deep Inferior Epigastric Perforator Flap Harvest Decreases Donor Site Complications

BACKGROUND

Donor site complications are a significant source of morbidity for patients undergoing abdominal-based free flap breast reconstruction, but there is a paucity of data regarding minimizing these postoperative complications. We hypothesize that selective ablation of the umbilicus at the time of deep inferior epigastric perforator (DIEP) harvest decreases the incidence of umbilical and abdominal wall complications in high-risk patients.

METHODS

A retrospective review was performed of all patients (n = 117) who underwent DIEP harvest with concomitant umbilical ablation from 2010 to 2015. This cohort was paired with 117 patients who underwent DIEP harvest without umbilical ablation. Preoperative risk factors, intraoperative factors, and postoperative complications were compared.

RESULTS

The umbilical ablation group had significantly higher body mass index (30.9 vs 27.4 kg/m, P < 0.001), presence of umbilical scar (20.9% vs 5.3%, P < 0.001), umbilical hernia (82.9% vs 8.5% P < 0.001), ventral hernia (23.9% vs 1.7%, P < 0.001), and rectus diastasis (10.3% vs 2.6%, P = 0.016). There were no significant differences of smoking, diabetes mellitus, hypertension, prior abdominal surgery, or midline abdominal scar. The umbilical ablation group had a significantly lower rate of postoperative abdominal wound dehiscence and skin loss (11.1% vs 22.2%, P = 0.023) and overall donor site complications (24.8% vs 39.3%, P = 0.017). There was no significant difference in incidence of cellulitis, seroma, or abscess. Mean follow-up time was 1.8 years.

CONCLUSIONS

Selective umbilical ablation in high-risk patients at the time of abdominal flap harvest can result in significantly fewer donor site wound complications, even in the setting of increased risk factors for poor wound healing. This is likely due to avoidance of umbilical incisions and decreased upper abdominal skin undermining. We conclude that umbilical ablation is a viable option to minimize donor site complications, especially in high-risk patients.

VIDAS® Enzyme-Linked Immunofluorescent Assay for Detection of Listeria in Foods: Collaborative Study

The VIDAS LIS method and the traditional culture methods for detection of Listeria species in food were evaluated in a multilaboratory comparative study. The 6 foods tested were either naturally contaminated or inoculated with 3 different concentrations of Listeria. Results for each food and each contamination level with the VIDAS LIS method were as good as or better than those obtained with the traditional culture method. Of 1558 samples tested, 935 were positive: 839 by the VIDAS method and 809 by standard culture methods. Overall false negative rates were 10.3 and 13.5% for the VIDAS LIS and culture methods, respectively. The false positive rate for the VIDAS LIS assay was 1.4% based on 9 VIDAS LIS positive assays that did not confirm positive by isolation of Listeria. The agreement between the VIDAS LIS and culture methods for all samples tested was 86%.

Discovery of selective urokinase plasminogen activator (uPA) inhibitors as a potential treatment for multiple sclerosis

We report here the design and synthesis of a novel series of benzylamines that are potent and selective inhibitors of uPA with promising oral availability in rat. Further evaluation of one representative (ZK824859) of the new structural class showed that this compound lowered clinical scores when dosed in either acute or chronic mouse EAE models, suggesting that uPA inhibitors of this type could be useful for the treatment of multiple sclerosis.

A novel inhibitor of activated thrombin-activatable fibrinolysis inhibitor (TAFIa) – Part I: Pharmacological characterization

We have discovered a novel small-molecule (3-phosphinoylpropionic acid) inhibitor of activated thrombin activatable fibrinolysis inhibitor (TAFIa), BX 528, which had an IC50 of 2 nM in an enzymatic assay and 50 nM in an in-vitro clot lysis assay, with 3,500- to 35,000-fold selectivity against other carboxypeptidases, such as CPN, CPZ and CPD, and 5- and 12-fold selectivity against CPE (CPH) and CPB, respectively. At 10 µM, BX 528 had no significant activity (< 50% inhibition or antagonism) in a panel of 137 enzymes and receptors. It had no effects on blood coagulation and platelet aggregation up to 300 and 10 µM, respectively. The plasma half-life following intravenous administration was 0.85 hours in rats and 4.5 hours in dogs. No significant metabolism was detected in human, dog or rabbit hepatic microsomes, and no significant inhibition of cytochrome P450 3A4 and 2D6 up to 30 µM. No cytotoxic or cell proliferative effects were found in three hepatic and renal cell lines up to 300 µM and no mutagenic activity was seen in the Ames II screen. There were no significant hemodynamic effects in rats and dogs up to 100 and 30 mg/kg with peak plasma drug concentrations of ~1,000 and 300 µM, respectively. In an in-vivo complement activation model in guinea pigs, BX 528 showed minimal inhibition of plasma CPN activity up to 60 mg/kg with peak plasma concentrations up to 250 µM. Thus, these data demonstrate that BX 528 is a novel, potent, selective and safe TAFIa inhibitor.

Outcomes of an innovative training course in laparoscopic hernia repair

Introduction The Ethicon™ laparoscopic inguinal groin hernia training (LIGHT) course is an educational course based on three days of teaching on laparoscopic hernia surgery. The first day involves didactic lectures with tutorials. The second day involves practical cadaveric procedures in laparoscopic hernia surgery. The third day involves direct supervision by a consultant surgeon during laparoscopic hernia surgery on a real patient. We reviewed our outcomes for procedures performed on real patients on the final day of the course for early complications and outcomes. Methods A retrospective study was undertaken of patients who had laparoscopic hernia surgery as part of the LIGHT course from 2013 to 2015. A matched control cohort of patients who had elective laparoscopic hernia surgery over the study period was identified. These patients had their surgery performed by the same consultant general surgeons involved in delivering the course. All patients were followed up at 6 weeks postoperatively. Results A total of 60 patients had a laparoscopic inguinal hernia repair and 23 patients had a laparoscopic ventral hernia repair during the course. The mean operative time for laparoscopic inguinal hernia repair was 48 minutes for trainees (range 22-90 minutes) and 35 minutes for consultant surgeons (range 18-80 minutes). There were no intraoperative injuries or returns to theatre in either group. All the patients operated on during the course were successfully performed as daycase procedures. The mean operative time for laparoscopic ventral hernia repair was 64 minutes for trainees (range 40-120 minutes) and 51 minutes for consultant surgeons (range 30-130 minutes). Conclusions The outcomes of patients operated on during the LIGHT course are comparable to procedures performed by a consultant. Supervised operating by trainees is a safe and effective educational model in hernia surgery.

The threatened stomach: management of the acute gastric volvulus

INTRODUCTION

Acute presentation of gastric volvulus is a rare condition with a high mortality for acute ischaemia. This study was undertaken to investigate the acute management, diagnosis, and long-term outcomes of patients presenting with acute gastric volvulus.

METHODS

Cases were reviewed retrospectively from 2004 to 2014. Patients presenting as an emergency admission with acute gastric volvulus were included.

RESULTS

Thirty-six patients were included, five of whom had previous surgery. The mean age was 71 years old. All patients presented with vomiting and chest/epigastric pain. CT was diagnostic in all 26 patients. Barium swallow was diagnostic in two/four patients. OGD was diagnostic in 9 of 20 patients. All patients had an NG tube placed, and eight patients were treated conservatively and made a full recovery. Twenty-nine patients proceeded to surgery. Nine had a laparoscopic repair with two open conversions. Four patients had gastric necrosis, and all had open surgery with resection. Three patients had a mediastinal perforation, and one patient required an additional thoracotomy. All patients with viable stomach had a hiatal repair (where appropriate), 11 had a gastropexy, and 11 had a fundoplication. Mortality for gastric necrosis/perforation was 30 %. Mean postoperative stay was 4 days for laparoscopic repair and 8 days for uncomplicated open surgery. Nine of twenty-nine had transient dysphagia postoperatively. Three of eight patients treated conservatively had an elective procedure subsequently.

CONCLUSIONS

Acute paraoesophageal hiatus hernia requires early resuscitation and diagnosis. CT should be favoured in assessment, and an NG tube placed promptly. A conservative management may be considered safely in stable patients. Surgical management should be prompt for unstable patients. Gastric ischaemia or perforation has a mortality of 30 %. Laparoscopic repair has a shorter postoperative stay, but has a higher recurrence rate. Surgery for patients without gastric ischaemia has good long-term outcomes with minimal morbidity.

Diffuse large B-cell lymphoma (DLBCL) in the bypassed stomach after obesity surgery

Laparoscopic Roux-en-Y gastric bypass is the most commonly performed surgical procedure for obesity and, consequently, post-operative patients are increasingly encountered by all specialties. This is a case of a patient presenting with abdominal pain, nausea and fever 9 months following gastric bypass surgery caused by diffuse large B-cell lymphoma (DLBCL) in the bypassed stomach. It demonstrates well that symptoms that may normally be considered 'red-flags' may not be as obvious or specific following an operation. The case also indicates the importance of considering diagnoses unrelated to surgery presenting in the post-operative period (especially when conventional investigation methods are not feasible), and the potential danger of assuming they are due to the operation alone; had this occurred in this patient then a malignancy may have been missed. This is only the second reported case of DLBCL in the bypassed stomach, and the third for lymphoma of any type.

Diaphragmatic disease of the colon: systematic review

AIM

Diaphragmatic disease is rare. This review aims to increase awareness of this condition and its management.

METHOD

A literature search was conducted using the key terms 'colon' or 'colonic' in combination with 'diaphragm' or 'diaphragm disease' for publications until August 2012. All cases of colonic diaphragm syndrome were identified and the required data were collected.

RESULTS

Forty-five cases of colon diaphragm disease were included. The highest incidence was in the seventh decade of life, with a female preponderance (40F:5M). Most patients presented with chronic (median 3 months) and multiple symptoms. The median use of nonsteroidal anti-inflammatory drugs (NSAIDs) was 5 years including diclofenac as the most commonly used NSAID. Colonoscopy was the most informative investigation and the ascending colon was the most common site of diaphragm disease. Nearly two-thirds of the patients were treated by discontinuing NSAID treatment combined with other forms of treatment, mostly surgery.

CONCLUSION

Diaphragm disease of the colon is a rare condition associated with long-term use of NSAIDs with a range of presentations and symptoms. Based on this review, when colon diaphragm disease is diagnosed we would recommend a trial cessation of NSAIDs. Therapeutic endoscopic techniques should be considered but surgery may be required for definitive treatment.

Radiological and clinical examination in the diagnosis of Spigelian hernias

INTRODUCTION

Spigelian hernia are rarely reported lateral abdominal wall hernias. Clinical diagnosis of a suspected hernia can be challenging owing to vague presenting symptoms and signs. This study aimed to investigate the accuracy of preoperative imaging and clinical examination in the diagnosis of Spigelian hernias.

METHODS

A retrospective analysis was performed of patients who presented to North Tyneside and Wansbeck General Hospitals between 1998 and 2010. All patients were assessed by a consultant general surgeon in the outpatient clinic or on the surgical admissions ward. Patients were included who presented with a history suggestive of a Spigelian hernia and a palpable lump or equivocal clinical examination. All patients proceeded to surgery, which was used as the reference standard.

RESULTS

Overall, correlation with operative findings showed computed tomography (CT) to have a sensitivity of 100% and a positive predictive value (PPV) of 100%. Ultrasonography had a sensitivity of 90% and a PPV of 100%. Clinical assessment alone had a sensitivity of 100% and a PPV of 36%.

CONCLUSIONS

This study shows that ultrasonography and CT have a high sensitivity and PPV in relation to occult Spigelian hernias. When no obvious Spigelian hernia is present, patients should be evaluated with radiological investigation to establish a diagnosis. Owing to diagnostic uncertainty, a laparoscopic approach should be favoured.

Male sexual assault and rape: who seeks counseling?

This work rests on responses from 219 male sexual assault and rape victims who self-reported their victimization in the 1994-1996 Violence and Threats of Violence Against Women and Men in the United States survey. The authors expected that men who reported being severely assaulted would be more likely than others to seek counseling. They defined severely assaulted as having been penetrated, assaulted with a weapon, threatened, self-reported sustaining physical injuries, sought medical care, and/or reported the assault to the police. However, in their logistic model that explores who sought counseling, only one variable was significant. The odds of seeking counseling for men who reported being penetrated had significantly lower odds of seeking counseling all else equal.

Meta-analysis of the use of glyceryl trinitrate ointment after haemorrhoidectomy as an analgesic and in promoting wound healing

INTRODUCTION

Glyceryl Trinitrate (GTN) ointment has been used to treat anal fissure and pain relief in haemorrhoids, but the value of its use post-haemorrhoidectomy as an analgesic and in wound healing is unclear. The side effect of headache has often been an associated problem. Therefore, a meta-analysis of randomised controlled trials was carried out investigating the role of GTN post-haemorrhoidectomy as an analgesic, its role in would healing and the unwanted incidence of headache.

METHOD

A structured literature search from 1966 to 2009, both paper and online, with no language barrier was carried out. 760 papers were identified and 5 randomised control trials which met the entry criteria were included in this study.

RESULTS

A total of 333 patients were included in the meta-analysis. The results revealed that GTN ointment was statistically significant in reducing pain on Day 3 and 7 compared to the placebo group. Day 3 shows a pain score of - 1.51 (p value of 0.029) and Day 7 by - 1.66 (p value of 0.014) respectively. However, it was not significant in reducing pain on Day 1. The Odds ratio for wound healing after GTN treatment at 3 weeks was 3.57 (P < 0.0001) when compared to the placebo group. Side effect of headache was not statistically significant.

CONCLUSION

This meta-analysis has shown that GTN ointment used post-haemorrhoidectomy has a significant analgesic effect in the intermediate time period (ie. Days 3-7). It also significantly improved wound healing at 3 weeks.

Incarcerated lumbar hernia: a rare presentation

This case illustrates the diagnostic uncertainty seen in lumbar herniation as a rare cause of large bowel obstruction.

Circumstances surrounding male sexual assault and rape: findings from the National Violence Against Women Survey

Much work in the area of male sexual assault and rape relies on small clinical samples. From these samples, researchers reported that most male victims were physically injured during the attack and that penetration occurred. This work rests on a subsample of 219 men from the 1994-1996 Violence and Threats of Violence Against Women and Men in the United States Survey. Findings from the National Violence Against Women Survey (NVAW) show that the vast majority of male sexual assault victims reported that they were not physically injured during the assault, that a weapon was not used, that there was no substance use at the time of the assault, and that penetration did not occur. Only 29% of male respondents in the NVAW sought medical or psychological help after the assault. Prior work may have overrepresented men who reported being physically injured and/or penetrated. An analysis is presented of how those who presented for help in the NVAW differ from the whole sample. Results show that men who presented for help were more likely to have reported being physically injured during the assault and that penetration occurred. Thus, findings from prior work make sense; however, they may not be representative of male assault victims as a whole.

Thiophene-anthranilamides as highly potent and orally available factor Xa inhibitors

There remains a high unmet medical need for a safe oral therapy for thrombotic disorders. The serine protease factor Xa (fXa), with its central role in the coagulation cascade, is among the more promising targets for anticoagulant therapy and has been the subject of intensive drug discovery efforts. Investigation of a hit from high-throughput screening identified a series of thiophene-substituted anthranilamides as potent nonamidine fXa inhibitors. Lead optimization by incorporation of hydrophilic groups led to the discovery of compounds with picomolar inhibitory potency and micromolar in vitro anticoagulant activity. Based on their high potency, selectivity, oral pharmacokinetics, and efficacy in a rat venous stasis model of thrombosis, compounds ZK 814048 (10b), ZK 810388 (13a), and ZK 813039 (17m) were advanced into development.

Antibodies neutralizing hepsin protease activity do not impact cell growth but inhibit invasion of prostate and ovarian tumor cells in culture

Hepsin is a type II transmembrane serine protease that is expressed in normal liver, and at lower levels in kidney, pancreas, and testis. Several studies have shown that hepsin mRNA is significantly elevated in most prostate tumors, as well as a significant fraction of ovarian and renal cell carcinomas and hepatomas. Although the overexpression of mRNA in these tumors has been extensively documented, there has been conflicting literature on whether hepsin plays a role in tumor cell growth and progression. Early literature implied a role for hepsin in human tumor cell proliferation, whereas recent studies with a transgenic mouse model for prostate cancer support a role for hepsin in tumor progression and metastases. To evaluate this issue further, we have expressed an activatable form of hepsin, and have generated a set of monoclonal antibodies that neutralize enzyme activity. The neutralizing antibodies inhibit hepsin enzymatic activity in biochemical and cell-based assays. Selected neutralizing and nonneutralizing antibodies were used in cell-based assays with tumor cells to evaluate the effect of antibodies on tumor cell growth and invasion. Neutralizing antibodies failed to inhibit the growth of prostate, ovarian, and hepatoma cell lines in culture. However, potent inhibitory effects of the antibodies were seen on invasion of ovarian and prostate cells in transwell-based invasion assays. These results support a role for hepsin in tumor cell progression but not in primary tumor growth. Consistent with this, immunohistochemical experiments with a mouse monoclonal antibody reveal progressively increased staining of prostate tumors with advanced disease, and in particular, extensive staining of bone metastatic lesions.

A model of the acid sphingomyelinase phosphoesterase domain based on its remote structural homolog purple acid phosphatase

Sequence profile and fold recognition methods identified mammalian purple acid phosphatase (PAP), a member of a dimetal-containing phosphoesterase (DMP) family, as a remote homolog of human acid sphingomyelinase (ASM). A model of the phosphoesterase domain of ASM was built based on its predicted secondary structure and the metal-coordinating residues of PAP. Due to the low sequence identity between ASM and PAP (approximately 15%), the highest degree of confidence in the model resides in the metal-binding motifs. The ASM model predicts residues Asp 206, Asp 278, Asn 318, His 425, and His 457 to be dimetal coordinating. A putative orientation for the phosphorylcholine head group of the ASM substrate, sphingomyelin (SM), was made based on the predicted catalysis of the phosphorus-oxygen bond in the active site of ASM and on a structural comparison of the PAP-phosphate complex to the C-reactive protein-phosphorylcholine complex. These complexes revealed similar spatial interactions between the metal-coordinating residues, the metals, and the phosphate groups, suggesting a putative orientation for the head group in ASM consistent with the mechanism considerations. A conserved sequence motif in ASM, NX3CX3N, was identified (Asn 381 to Asn 389) and is predicted to interact with the choline amine moiety in SM. The resulting ASM model suggests that the enzyme uses an SN2-type catalytic mechanism to hydrolyze SM, similar to other DMPs. His 319 in ASM is predicted to protonate the ceramide-leaving group in the catalysis of SM. The putative functional roles of several ASM Niemann-Pick missense mutations, located in the predicted phosphoesterase domain, are discussed in context to the model.

Dead space and paediatric anaesthetic equipment: a physical lung model study*

Untested assumptions have been made with regard to functional dead space in facemasks, filters and breathing systems used in children for the administration of inhalation anaesthesia. Total functional dead space was measured in various combinations of this equipment applied to a spontaneous ventilation lung model with parameter settings appropriate for infants of 7-8 kg. We found that functional dead space was too large to allow for spontaneous ventilation of the lungs when a breathing filter was fitted. There was minimal relationship between size of the facemask and functional dead space; however, the provision of 22-mm female inlets to facemasks achieved proportionately less functional dead space than with 15-mm male inlets. Regardless of the apparatus used and the magnitude of the dead space, the leak induced when a poorly fitting facemask was used dramatically reduced the dead space of the breathing system - to near optimal conditions - by moving the alveolar gas elimination point to within the facemask itself.

Spinal cord stimulation does not change peripheral skin blood flow in patients with neuropathic pain

BACKGROUND AND OBJECTIVE

Spinal cord stimulation has been used successfully for many years in the management of neuropathic pain. Nociceptive pathways are closely integrated into many autonomic reflexes. The aim was to test the hypothesis that pain relief caused by spinal cord stimulation is related to changes in peripheral skin blood flow.

METHODS

Twelve patients with spinal cord stimulators implanted as a treatment for neuropathic pain were entered into the study. Laser Doppler perfusion scanning was used as a direct method for selective measurement of changes in skin (peripheral) blood flow. Measurements were taken before and after the onset of spinal cord stimulation over the site of its sensory projection. The degree of pain relief due to spinal cord stimulation and the skin temperature of each patient were also recorded.

RESULTS

Apart from one patient, spinal cord stimulation did not change skin blood flow in a statistically significant manner.

CONCLUSIONS

Pain relief due to spinal cord stimulation is not related to changes of skin blood flow.

Laboratory and clinical comparisons of the Streamlined Liner of the Pharynx Airway (SLIPA) with the laryngeal mask airway

The Streamlined Liner of the Pharynx Airway (SLIPA) is a new inexpensive disposable supraglottic airway designed to seal without the use of an inflatable cuff. It comprises a hollow blow-moulded soft plastic airway shaped to form a seal in the pharynx. Being hollow, liquid entrapment is possible and this may provide effective protection against aspiration. A model silicone rubber pharynx with an 'oesophageal' tube for injecting volumes of regurgitant liquid was designed to evaluate the SLIPA and the standard and ProSeal laryngeal mask airways during positive-pressure ventilation. A linear relationship between the volume 'regurgitated' and the volume 'aspirated' was found with the laryngeal mask airway and the ProSeal laryngeal mask airway with the drainage tube clamped. Both the ProSeal laryngeal mask airway with an open drainage tube and the SLIPA, but not the standard laryngeal mask airway, provided effective protection against 'aspiration' during positive-pressure ventilation using the model. In a clinical study, 120 patients were randomly allocated to receive controlled ventilation of the lungs via the standard laryngeal mask airway or the SLIPA. Both devices were equally easy to insert and satisfactory for airway management.

Head injury and alexithymia: implications for family practice care

BACKGROUND

Alexithymia, a deficit in emotional information processing, and a history of head injury have both been found to be related to high rates of psychosomatic illness, substance abuse, depression, and utilization of primary care services. To date, no study has examined the potential comorbidity of alexithymia and head injury in a family practice setting, a necessary step in evaluating the aetiologic role of head injury in the development of alexithymia. The goals of this study are to establish prevalence of head injury and alexithymia in a family practice setting and to evaluate the relation, if present, between the two.

METHODS

Patients (n =135) of a family practice residency facility were screened using the Traumatic Brain Injury Questionnaire and the Toronto Alexithymia Scale-20.

RESULTS

Forty-nine per cent of the participants reported a history of head injury and 18% were alexithymic. Those with a history of head injury had significantly higher scores of alexithymia. Chi-square analysis indicated a relation between head injury and alexithymia.

CONCLUSIONS

The high rates of self-reported history of head injury in family practice settings, particularly in the context of alexithymia, may adversely affect a physician's ability to care for these patients. Increasing physicians' awareness of head injury and the potential mediating role of alexithymia in medical and psychological illness may facilitate effective diagnosis and patient-physician communication.

Intermediate care. A new way through

The development of intermediate care, which will keep patients out of hospital, depends on co-operation between specialists and primary care organisations. Community hospitals and some nursing homes will have to take on new roles as community treatment centres. Action is needed to unlock budgets currently tied up in hospital services. The potential for consultants and GPs to work together to commission services needs to be unleashed. Clinical criteria should be established for referral to these services.

The 1998 APHA Annual Lecture. What the UK can teach the US about health care

This paper was originally presented at the Annual Lecture of the American Public Health Association, 16th November 1998.

CC chemokine receptor 5-mediated signaling and HIV-1 Co-receptor activity share common structural determinants. Critical residues in the third extracellular loop support HIV-1 fusion

There is a close correspondence between the ability of RANTES and macrophage inflammatory proteins 1alpha and 1beta to activate CC chemokine receptor 5 (CCR5) and the ability to inhibit CCR5-dependent membrane fusion mediated by the envelope glycoprotein of human immunodeficiency virus (HIV), type 1. This finding suggests that some of the structural determinants for CC chemokine/CCR5 interactions and CCR5 HIV-1 fusion co-receptor activity may be shared. Recent studies using human CCR5/CCR2B chimeras have suggested that the determinants of CCR5 co-receptor activity are complex and may involve multiple extracellular receptor domains and that viral co-receptor activity is dissociable from ligand-dependent signaling responses. However, conclusive evidence demonstrating an important role for the second and third extracellular regions of human CCR5 is lacking. Furthermore, to determine whether the determinants for CCR5 co-receptor activity overlap with those required for agonist activity, studies that compare the chemokine specificity for inhibition of envelope-mediated cell fusion and the agonist profile of chimeric receptors are necessary. In the present report, using a series of CCR5/CCR2B chimeras we ascribe an important role for the second and third extracellular loop of CCR5 in supporting the co-receptor activity of CCR5. We also provide evidence that the intracytoplasmic tail of CCR5 does not play an important role in supporting HIV-1 entry. The hypothesis that the structural determinants for CC chemokine/CCR5 interactions and CCR5 HIV-1 fusion co-receptor activity may be shared was confirmed by two novel observations: first, the fusion activity supported by two hybrid receptors could be inhibited by both RANTES and monocyte chemoattractant protein-1, chemokines specific to CCR5 and CCR2B, respectively; and second, the chemokine specificity for inhibition of envelope-mediated cell fusion matched the agonist profile of these hybrid receptors. These data shed new light on the structural determinants involved in these distinct activities of CCR5 and may have important implications for the development of CCR5-targeted anti-viral compounds.

Recombinant soluble human thrombomodulin: a randomized, blinded assessment of prevention of venous thrombosis and effects on hemostatic parameters in a rat model

Thrombomodulin is an endothelial surface receptor that binds thrombin and accelerates the activation of protein C. We compared the effects of a recombinant thrombomodulin analog (TME), recombinant hirudin (r-HIR), heparin sodium (HEP), and normal saline (Control) on thrombus formation, activated partial thromboplastin time (APTT), thrombin time (TT), platelet aggregation and tail transection bleeding time (BT) in a rat model of vena cava thrombosis.

RESULTS

TME, r-HIR and HEP prevented venous thrombosis in this model in a dose-dependent manner. At the dose required to reduce vena cava thrombosis by 50% (ED50), TME did not prolong the APTT or TT as did HEP and r-HIR. Platelet aggregation in response to thrombin was not effected by TME but was inhibited by both r-HIR and HEP. BT did not differentiate the agents tested.

CONCLUSION

TME inhibited venous thrombosis in a rat vena cava model with less effect on hemostatic variables than HEP or r-HIR.

Intravenous recombinant soluble human thrombomodulin prevents venous thrombosis in a rat model

Thrombomodulin is an endothelial surface thrombin receptor. Thrombin bound to thrombomodulin loses all procoagulant activity and instead activates the protein C anticoagulant pathway. We developed a recombinant thrombomodulin analog and compared the effects of recombinant thrombomodulin (100 micrograms/ea), saline (controls), recombinant hirudin (1.0 mg/kg), and heparin (100 units/kg) on thrombus formation, activated partial thromboplastin time, and tail transection bleeding time in a rat model of stasis-induced venous thrombosis. Results showed that thrombus was detected in the vena cava in six of the six rats treated with saline solution, in zero of the six rats treated with recombinant thrombomodulin (p less than 0.05), in one of six rats treated with recombinant hirudin (p less than 0.05), and in zero of six rats treated with heparin (p less than 0.05). The activated partial thromboplastin time in rats receiving recombinant thrombomodulin was slightly longer than controls (22 +/- 8 vs 37 +/- 6, p less than 0.05). The bleeding times in rats receiving recombinant thrombomodulin were approximately twice as long as controls (215 +/- 68 vs 545 +/- 173, p = 0.037). In all rats treated with recombinant hirudin or heparin, activated partial thromboplastin times were greater than 120 seconds and bleeding times were greater than 1200 seconds. We conclude that recombinant thrombomodulin inhibits venous thrombosis in a rat model with less prolongation of activated partial thromboplastin time and bleeding time than heparin or hirudin.