Trichomonas vaginalis: an unusual presentation

We report a case of Trichomonas vaginalis (TV) presenting as vulval ulceration in a 41-year-old woman. There was complete resolution of her symptoms only after oral tinidazole. The delayed diagnosis and importance of using the correct tests for the diagnosis of TV are discussed.

Population pharmacokinetics of enoxaparin in infants, children and adolescents during secondary thromboembolic prophylaxis: a cohort study

BACKGROUND

Enoxaparin has been extensively studied in adults on its safety and efficacy during prevention of symptomatic thromboembolism when acute anticoagulation or secondary prevention is required as a result of venous thrombosis or stroke. In children, it is still used off-label and little is known about the pharmacokinetics in children.

OBJECTIVES

The aim of the present study was to evaluate whether a once- or twice-daily dosing regimen would be feasible in children to achieve appropriate plasma levels of enoxaparin.

PATIENTS/METHODS

A population pharmacokinetic model was developed using anti-factor (F)Xa activity data from 126 children (median age: 5.9 years) receiving enoxaparin either as a once- or twice-daily dosing regimen.

RESULTS

A two-compartment model was adequate for describing the enoxaparin kinetics. Body weight proved to be the most predictive covariate for clearance and central volume of distribution: clearance 15 mL h⁻¹ kg⁻¹, central volume of distribution 169 mL kg⁻¹, intercompartmental clearance 58 mL h⁻¹, peripheral volume of distribution 10 L and absorption rate 0.414 h⁻¹. Interindividual variability was found to be 54% for clearance and 42% for volume of distribution.

CONCLUSION

The model is capable of describing all age groups and dosing levels of our population and predicts 12 h and 24 h enoxaparin activities sufficiently. According to our results, a once-daily enoxaparin dosing regimen with frequent monitoring is feasible. In 53.2% of the patients the median 24 h trough level was above the desired range of 0.1 IU mL⁻¹ anti-FXa activity for prophylaxis therapy.

322. PROTEOMIC AND FUNCTIONAL ANALYSIS OF HUMAN SPERM DETERGENT RESISTANT MEMBRANES

Mammalian spermatozoa attain the ability to fertilize an oocyte as they negotiate the female reproductive tract. This acquisition of functional competence is preceded by an intricate cascade of biochemical and functional changes collectively known as ‘capacitation’. Among the universal correlates of the capacitation process is a remarkable remodeling of the lipid and protein architecture of the sperm plasma membrane. While the fundamental mechanisms that underpin this dynamic reorganization remain enigmatic, emerging evidence has raised the prospect that it may be coordinated, at least in part, by specialized membrane microdomains, or rafts. In the studies described herein we have demonstrated that human spermatozoa express recognized markers of membrane rafts. Further, upon depletion of cellular cholesterol through either physiological (capacitation) or pharmacological (methyl-β-cyclodextrin) intervention, these membrane rafts appear to undergo a polarized redistribution to the peri-acrosomal region sperm head. The polarized targeting of membrane rafts to the sperm head encourages speculation that they represent platforms for the organization of proteins involved in sperm-oocyte interactions. Support for this notion rests with the demonstration that membrane rafts isolated on the basis of their biochemical composition in the form of detergent resistant membranes (DRMs), possess the ability to adhere to homologous zona pellucida. Furthermore a comprehensive proteomic analysis of the DRMs identified a number of proteins known for their affinity for the zona pellucida in addition to other candidates putatively involved in the mediation of downstream binding and/or fusion with the oolemma. Collectively these data afford novel insights into the sub-cellular localization and potential functions of membrane rafts in human spermatozoa.

Gamma Knife surgery in the management of radioresistant brain metastases in high-risk patients with melanoma, renal cell carcinoma, and sarcoma

OBJECT

The purpose of this study was to examine the results of using Gamma Knife surgery (GKS) for brain metastases from classically radioresistant malignancies.

METHODS

The authors retrospectively reviewed the records of 76 patients with melanoma (50 patients), renal cell carcinoma (RCC; 23 patients), or sarcoma (3 patients) who underwent GKS between August 1998 and July 2007. Overall patient survival, intracranial progression, and local progression of individual lesions were analyzed.

RESULTS

The median age of the patients was 57 years (range 18-85 years) and median Karnofsky Performance Scale (KPS) score was 80 (range 20-100). Sixty-two patients (81.6%) had uncontrolled extracranial disease. A total of 303 intracranial lesions (average 3.97 per patient, range 1-27 lesions) were treated using GKS. More than 3 lesions were treated in 30 patients (39.5%). Median GKS tumor margin dose was 18 Gy (range 8-30 Gy). Thirty-seven patients (48.7%) underwent whole brain radiation therapy. The actuarial 12-month rate for freedom from local progression for individual lesions was 77.7% and was significantly higher for RCC compared with melanoma (93.6 vs 63.0%; p = 0.001). The percentage of coverage of the prescribed dose to target volume was the only treatment-related variable associated with local control: 12-month actuarial rate of freedom from local progression was 71.4% for lesions receiving >or= 90% coverage versus 0.0% for lesions receiving < 90% (p = 0.00048). Median overall survival was 5.1 months after GKS and 8.4 months after the discovery of brain metastases. Univariate analysis revealed that KPS score (p = 0.000004), recursive partitioning analysis class (p = 0.00043), and single metastases (p = 0.028), but not more than 3 metastases, to be prognostic factors of overall survival. The KPS score remained significant after multivariate analysis. Overall survival for patients with a KPS score >or= 70 was 7.1 months compared with 1.3 months for a KPS score <or= 60 (p = 0.013).

CONCLUSIONS

Gamma Knife surgery is an effective treatment option for patients with radioresistant brain metastases. In this setting, KPS score appeared to be a more important factor in predicting survival than having > 3 metastases. Higher rates of local tumor control were achieved for RCC in comparison with melanoma, and this may have an effect on survival in some patients. Although outcomes generally remained poor in this study population, these results suggest that GKS can be considered as a treatment option for many patients with radioresistant brain metastases, even if these patients have multiple lesions.

KIDCLOT: the importance of validated educational intervention for optimal long term warfarin management in children

BACKGROUND

Advances in medical and surgical therapy in children have resulted in increased survival in children with primary illnesses. However, thrombosis is a serious complication of this success and results in mortality and morbidity. Prevention or treatment of thrombosis using warfarin is challenging in children due to its narrow therapeutic index and the unique differences in children, including variable nutritional intake and the occurrence of common concomitant viral or bacterial illnesses which alter warfarin metabolism. The variable response to warfarin in children necessitates frequent International Normalized Ratio (INR) monitoring. Education may improve time in therapeutic range (TTR) a measure of warfarin effect, and a surrogate for patient adherence, safety and efficacy.

METHODS

The Pediatric Anticoagulation program (Stollery Children's Hospital) developed a novel child-focused educational program KIDCLOT-POC about warfarin therapy and POC-INR meter use. A total of twenty eight children, and their caregivers, participated in KIDCLOT-POC. Questionnaire score comparisons and practical demonstrations assessed the learners' theoretical and practical knowledge of warfarin management.

RESULTS

In caregivers, the median pre, post and knowledge retention questionnaire scores were 50 (IQR 27), 93 (IQR 6) (p<0.0001) and 96 (IQR 6) (p<0.0001), respectively. In the 18 children who were >or=6 years of age, post and knowledge retention questionnaire scores were 90 (IQR 16) and 92 (IQR 23) (p=0.44), respectively. The TTR for all children was 81.7% (SD 13.1).

CONCLUSIONS

Implementation of KIDCLOT-POC program appears to promote high knowledge development and retention in children and caregivers and high TTR with no adverse events.

Proteolytic cleavage of carboxypeptidase N markedly increases its antifibrinolytic activity

BACKGROUND

Carboxypeptidase N (CPN) is a constitutively active basic carboxypeptidase sharing specificity with activated thrombin-activable fibrinolysis inhibitor (TAFIa). Generally, CPN is regarded as being non-antifibrinolytic. However, this assumption has not been thoroughly investigated, particularly with respect to long-term antifibrinolysis. In addition, a recent report has shown that plasmin cleavage increases the catalytic activity of CPN. Therefore, we investigated the antifibrinolytic properties of CPN and plasmin-cleaved CPN (CPNc).

METHODS

CPN was incubated with plasmin for various periods of time and the prolongation of clot lysis at various concentrations of CPN/CPNc mixture was investigated in TAFI-depleted plasma. CPN cleavage was analyzed by electrophoresis and catalytic activity was determined by monitoring cleavage of the small substrate, FA-Ala-Lys.

RESULTS

CPN exhibited antifibrinolytic properties in plasma clot lysis assays when present at supraphysiological concentrations. Depletion of CPN from plasma decreased the lysis time of clots formed from minimally diluted plasma at low tissue-type plasminogen activator (t-PA) concentrations. Plasmin cleavage of CPN markedly increased the antifibrinolytic properties. CPN and CPNc prolonged lysis in a non-saturable, dose-dependent, and t-PA-dependent manner. At sufficient concentration, CPN and CPNc prolonged lysis at least forty-fivefold. CPNc was 700% more antifibrinolytic than CPN but only 7% more active toward FA-Ala-Lys. The active site inhibitor GEMSA eliminated the antifibrinolytic effects of CPN and CPNc. Antifibrinolytic activity correlated with cleavage of active and/or regulatory subunits, presumably generating heterodimeric CPNc.

CONCLUSIONS

Limited proteolysis of CPN by plasmin generates an enzyme with greatly increased antifibrinolytic properties. We speculate that (patho)physiological proteolysis of CPN may generate a long-term antifibrinolytic enzyme.

Total Syntheses of Conformationally Locked Difluorinated Pentopyranose Analogues and a Pentopyranosyl Phosphate Mimetic

Trifluoroethanol has been elaborated, via a telescoped sequence involving a metalated difluoroenol, a difluoroallylic alcohol, [2,3]-Wittig rearrangement, and ultimately an RCM reaction and requiring minimal intermediate purification, to a number of cyclooctenone intermediates. Epoxidation of these intermediates followed by transannular ring opening or dihydroxylation, then transannular hemiacetalization delivers novel bicyclic analogues of pentopyranoses, which were elaborated (in one case) to an analogue of a glycosyl phosphate.

Doses greater than 85 Gy and two isocenters in Gamma Knife surgery for trigeminal neuralgia: updated results

Object

The purpose of this study was to assess the efficacy of Gamma Knife surgery (GKS) in treating patients with trigeminal neuralgia (TN). Preliminary results of this study were previously reported. The updated results are reported in this paper.

Methods

Ninety seven patients with TN refractory to medical or surgical management underwent GKS between September 1998 and October 2005. Fifteen patients had multiple sclerosis (MS). The radiation dose was escalated from 70 to 99 Gy. The Barrow Neurological Institute Pain Scale (BNIPS) was used to assess pain before and after GKS.

Eighty-four patients were available for evaluation with a mean follow up of 8.9 months. The overall response and complete response rates were 70.2% and 36.9%, respectively. At 12 months, there was a greater improvement in BNIPS scores for patients who were treated with two isocenters compared with those treated with a single isocenter. The mean percentage of pain decrease was 56.26% compared with 11.53% (p < 0.001). Patients treated with two isocenters rather than one and patients receiving greater than 85 Gy compared with lower doses had a longer duration of response. Only nine patients (11%) had mild numbness attributable to the GKS. Five of the nine patients experienced complete resolution of facial numbness on follow up. Patients with MS have a shorter duration of response compared with those without MS (p = 0.35).

Conclusions

These updated results show that GKS continues to be an effective therapy for TN. It appears there is an enhanced response with doses 85 Gy or more and with two isocenters without increased complications.

Specialist dermatology clinics for organ transplant recipients significantly improve compliance with photoprotection and levels of skin cancer awareness

BACKGROUND

Organ transplant recipients (OTRs) have 100-fold increased risk of developing squamous cell carcinomas. Cumulative exposure to ultraviolet radiation is the main risk factor and there is evidence that lack of dermatological surveillance may be responsible for poor levels of knowledge and photoprotection among OTRs.

OBJECTIVES

This study evaluated whether routine consultation in a specialist OTR dermatology clinic improves understanding of skin cancer risk and compliance with photoprotection measures.

METHODS

A cross-sectional questionnaire-based study was performed in a specialist OTR dermatology clinic at Bart's and the London NHS Trust, London, U.K. The subjects were 399 white-skinned patients under surveillance in a renal transplant clinic, who were sent a postal questionnaire from the renal transplant clinic. The main outcome measures were responses to the questionnaire regarding photoprotective practices and skin cancer risk awareness.

RESULTS

Two hundred and ninety-two of 399 (73%) responded, of whom 89% had previously attended the specialist dermatology clinic. Ninety-six per cent recalled receiving photoprotection advice at least once (85% from dermatologists); 92% reported use of sunscreen; 88% specifically dressed to photoprotect themselves; 96% directly avoided sun exposure during summer; 68% were aware that an increased risk of skin cancer was the reason that extra photoprotective measures were important after a transplant. Photoprotective measures and level of skin cancer awareness were significantly lower in those responders who had never attended the specialist clinic. No obvious bias was identified among nonresponders.

CONCLUSIONS

Skin cancer awareness and compliance with photoprotective measures in our patient population is generally greater than previously reported, suggesting that delivery of educational messages regarding skin cancer may be improved if provided in a specialist dermatological setting.

Manmade and natural radionuclides in north east Atlantic shelf and slope sediments: Implications for rates of sedimentary processes and for contaminant dispersion

Results are presented for a study of manmade and natural radionuclides in north east Atlantic continental shelf and slope sediments to the west of Scotland. The data are interpreted in the context of sediment mixing and accumulation processes and are used to establish the westward extent of contamination of the sediment system. Offshore shelf and slope sediments were found to have post-glacial sedimentation rates of the order of 1 cm ky(-1) but nearshore sediments had much higher accumulation rates of the order of 0.1 cm y(-1). Surface mixed layer depths of up to 6 cm were observed and non-local mixing affected most of the slope sediments, resulting in advective transport of surface sediment to depths of up to 10 cm. Biodiffusion coefficients for offshore shelf and slope sediments were dominantly in the range 10(-8) to 10(-9) cm2 s(-1). The study confirmed that seawater contaminated with Sellafield waste radionuclides is dominantly entrained to the east of 7 degrees W and, consistent with this, higher levels of Sellafield derived radionuclides were confined to nearshore sediments, with lower levels to the west of 7 degrees W. 238Pu/(239,240)Pu data indicated that Sellafield contributed 75-91% of the total plutonium in coastal sediment but only about 4-8% of the total in slope sediments. By analogy, it can be concluded that a similar situation will apply to other contaminants in seawater entering the north east Atlantic via the North Channel.

Star testing: a novel evaluation of intraocular lens optical quality

BACKGROUND

Despite the importance of optical quality of an intraocular lens (IOL) on visual outcomes following cataract surgery, objective data on their optical quality are not readily available, and manufacturing standards are industry regulated. The star test is a classic test of optical quality based on examination of the Airy disc and expanded diffraction rings of a point source of light, used mainly for telescope and microscope objectives.

METHODS

A physical model eye cell allowed star testing of IOLs under conditions similar to the optical environment in which they operate. 18 IOLs were tested and results compared to actual images produced by these lenses in the model eye cell. Quantitative measures of star testing performance were developed.

RESULTS

The optical performance of the IOLs varied, some performing very poorly. Most lenses (13/17) performed better in reverse orientation, while aberrations induced by the haptics of foldable IOLs were also detected. There was excellent correlation between actual images formed and star testing parameters.

CONCLUSION

Star testing IOLs was a novel biomedical application of a centuries old, inexpensive method. A concerning variation of optical quality was found, suggesting IOL optical performance data should be more readily available. Independent, authority mandated IOL optical quality standards should be developed, and results readily available to ophthalmologists.