Atypical choroid plexus papilloma: Diagnosis and differentials: A case report.

Atypical choroid plexus papilloma is a rare World Health Organization grade 2 intraventricular tumor arising from the epithelium of the plexus choroid with intermediate clinical-pathological features between the benign choroid plexus papilloma and the malignant choroid plexus carcinoma. The main criteria for differentiation are histopathologic, with difficulties in distinguishing it from choroid plexus papilloma based on imaging features. We report the case of a 4-year-old female presenting with headaches and altered mental status. Brain magnetic resonance imaging revealed a right lateral ventricular mass with some atypical characteristics, which were confirmed on pathological examination as an atypical choroid plexus papilloma.

Development of a membrane-based Gi-CASE biosensor assay for profiling compounds at cannabinoid receptors.

Introduction: The cannabinoid receptor (CBR) subtypes 1 (CB1R) and 2 (CB2R) are key components of the endocannabinoid system (ECS), playing a central role in the control of peripheral pain, inflammation and the immune response, with further roles in the endocrine regulation of food intake and energy balance. So far, few medicines targeting these receptors have reached the clinic, suggesting that a better understanding of the receptor signalling properties of existing tool compounds and clinical candidates may open the door to the development of more effective and safer treatments. Both CB1R and CB2R are Gαi protein-coupled receptors but detecting Gαi protein signalling activity reliably and reproducibly is challenging. This is due to the inherent variability in live cell-based assays and restrictions around the use of radioactive [35S]-GTPγS, a favoured technology for developing higher-throughput membrane-based Gαi protein activity assays. Methods: Here, we describe the development of a membrane-based Gαi signalling system, produced from membrane preparations of HEK293TR cells, stably overexpressing CB1R or CB2R, and components of the Gαi-CASE biosensor. This BRET-based system allows direct detection of Gαi signalling in both cells and membranes by monitoring bioluminescence resonance energy transfer (BRET) between the α and the ßγ subunits. Cells and membranes were subject to increasing concentrations of reference cannabinoid compounds, with 10 µM furimazine added to generate RET signals, which were detected on a PHERAstar FSX plate reader, then processed using MARS software and analysed in GraphPad PRISM 9.2. Results: In membranes expressing the Gi-CASE biosensor, the cannabinoid ligands profiled were found to show agonist and inverse agonist activity. Agonist activity elicited a decrease in the BRET signal, indicative of receptor activation and G protein dissociation. Inverse agonist activity caused an increase in BRET signal, indicative of receptor inactivation, and the accumulation of inactive G protein. Our membrane-based Gi-CASE NanoBRET system successfully characterised the potency (pEC50) and efficacy (Emax) of CBR agonists and inverse agonists in a 384-well screening format. Values obtained were in-line with whole-cell Gi-CASE assays and consistent with literature values obtained in the GTPγS screening format. Discussion: This novel, membrane-based Gαi protein activation assay is applicable to other Gαi-coupled GPCRs, including orphan receptors, allowing real-time higher-throughput measurements of receptor activation.

CYP102A1 peroxygenase catalyzed reaction via in situ H2O2 generation.

CYP102A1 is a promiscuous bacterial cytochrome P450 (CYP or P450) known for its diverse substrates and comparable activity with human P450 enzymes. The development of CYP102A1 peroxygenase activity can contribute significantly to human drug development and drug metabolite production. Peroxygenase has recently emerged as an alternative to a dependency of P450 on NADPH-P450 reductase and NADPH cofactor and gives more opportunity for practical application. However, the H2O2 dependency also leads to challenges regarding its practical application, in which the excessive H2O2 concentration causes the activation of the peroxygenases. Therefore, we need the optimization of H2O2 production to minimize oxidative inactivation. In this study, we report the CYP102A1 peroxygenase-catalyzed atorvastatin hydroxylation reaction with an enzymatic H2O2 generation using glucose oxidase. Random mutagenesis at the CYP102A1 heme domain was used to generate mutant libraries with high throughput screening of highly active mutants, which can pair with the in situ H2O2 generation. The setup of the CYP102A1 peroxygenase reaction was also possible for other statin drugs and could be developed to produce drug metabolites. We also found a relationship between enzyme inactivation and product formation during the catalytic reaction, supported by enzymatic in situ H2O2 supply. It can be suggested that the low product formation is due to enzyme inactivation.

Roles of Human Liver Cytochrome P450 Enzymes in Tenatoprazole Metabolism.

Tenatoprazole, a newly developed proton pump inhibitor candidate, was developed as an acid inhibitor for gastric acid hypersecretion disorders such as gastric ulcer and reflux esophagitis. It is known that tenatoprazole is metabolized to three major metabolites of 5'-hydroxy tenatoprazole, tenatoprazole sulfide, and tenatoprazole sulfone in human liver, primarily catalyzed by CYPs 2C19 and 3A4. While CYP2C19 prefers the hydroxylation of tenatoprazole at C-5' position, CYP3A4 is mainly involved in sulfoxidation reaction to make tenatoprazole sulfone. Tenatoprazole sulfide is a major human metabolite of tenatoprazole and is formed spontaneously and non-enzymatically from tenatoprazole. However, its metabolic fate in the human liver is not fully known. Furthermore, no systematic metabolic study has been performed to study tenatoprazole or tenatoprazole sulfide. Here, we studied the functions of human cytochromes P450 in the metabolic pathway of tenatoprazole and tenatoprazole sulfide by using recombinant human P450s and human liver microsomes. Both CYP 2C19 and CYP3A4 showed distinct regioselective and stereospecific monooxygenation activities toward tenatoprazole and tenatoprazole sulfide. Furthermore, a new major metabolite of tenatoprazole sulfide was found, 1'-N-oxy-5'-hydroxytenatoprzole sulfide, which has never been reported. In conclusion, the metabolic fates of tenatoprazole and tenatoprazole sulfide should be considered in the clinical use of tenatoprazole.

The objective assessment of the effects on cognition functioning among military personnel exposed to hypobaric-hypoxia: A pilot fMRI study.

OBJECTIVE: To identify regions of the brain affected during cognitive working memory during tasks to assess attention, planning and decision making among military aviation personnel who have chronic intermittent exposure to high altitude environment. METHOD: A case-control study was conducted in the Universiti Putra Malaysia among eight military personnel, four of whom had chronic intermittent exposure to high altitude training. They were divided into two groups, chronic intermittent exposure group (CE) (n=4) and a control group (n=4). They underwent a task-based functional magnetic resonance imaging (fMRI) that utilised spatial working memory task to objectively evaluate the neural activation in response to the Tower of London paradigm. Each correct answer was given a score of one and the maximum achievable score was 100%. RESULTS: A consecutive dichotomised group of CE (4/8) and control (4/8) of age-matched military aviation personnel with a mean age of 37.23±5.52 years; showed significant activation in the right middle frontal gyrus (MFG). This in turn was positively correlated with response accuracy. A significant difference in the response accuracy was noted among both the groups at p<0.05. CONCLUSION: At the minimum results of power analysis of this preliminary fMRI study, our group of aviation personnel who had chronic intermittent exposure to hypobaric hypoxic environment, did not have any significant decrease in cognitive function namely attention, decision-making and problem solving compared to controls during a working memory task.

Compression of the peroneal nerve by a neurofibroma originating from collaterals of the peroneal nerve: a case report.

BACKGROUND: Paralysis of the external popliteal sciatic nerve is a frequent pathological condition that occurs after trauma. However, etiologies other than trauma, such as tumors, are also possible. The sensory collaterals of the external popliteal sciatic nerve have a small territory of innervation at the knee, and tumors involving these nerves become symptomatic after compression of the motor nerves. We here describe the first reported case of this phenomenon. CASE PRESENTATION: This case involved a lesion compressing the origin of the external popliteal sciatic nerve of a 13-year-old Moroccan boy diagnosed with a neurofibroma. He developed functional impairment of his left lower limb during a football game, and examination revealed a steppage gait. The initial diagnosis was stretching of the peroneal nerve. The definitive diagnosis of a neurofibroma was revealed by imaging and confirmed by surgery and pathology. Treatment involved total removal of the tumor; however, our patient's steppage gait persisted. CONCLUSIONS: Our patient developed compression of the external popliteal sciatic nerve from a tumor growing on a collateral nerve. Early diagnosis is an absolute necessity in such cases. Trauma and tumors of sensory nerves can distort the diagnosis, as in this case. Ultrasound and magnetic resonance imaging can contribute to an accurate diagnosis in patients with neuropathy in the absence trauma or tomacula.

18F-FDG PET/CT as a potential predictor of survival in patient with oesophageal cancer: a preliminary result.

AIMS: A study was undertaken to investigate the value of pretreatment PET-CT in predicting survival in patients with oesophageal cancer (OC). METHODS: Between June 2010 and December 2011, 18 consecutive OC patients median (61.00 ± 12.07 years) with median survival of 7.5 month had a pretreatment PET-CT scan. Staging of the disease was made in accordance to the American Joint Committee on Cancer staging system (7th edition) and grouped as stage I-IIA and stage IIB-IV. Maximum standardized uptake value (SUVmax), size of a primary tumour and the presence of fluorodeoxyglucose (FDG)-avid lymph nodes were evaluated for all patients. Survival was analysed using the Kaplan-Meier product limit method and Cox proportional hazards regression model. RESULTS: PET-CT stages I-IIA and IIB-IV had a 1-year survival of 50% and 25%, respectively. Patient with size of primary tumour (<4.5 cm) had significantly (p < 0.036) better survival than those with large size (>4.5 cm). Multivariate Cox regression analysis showed that SUVmax of >5.5 in the primary tumour [hazard ratio (HR) 23.017; 95% confidence interval, p = 0.038] and the presence of FDG-avid lymph node (HR 1.248; p = 0.028) were strongly predictive of poor overall survival on multivariate analysis. CONCLUSION: Pretreatment 18F-FDG PET-CT SUVmax of a primary tumour and the presence of FDG-avid lymph nodes independently predict survival in patients with oesophageal carcinoma which may potentially be used as surrogate markers for prognostic and therapeutic purposes.

Application of an indirect fluorescent antibody assay for the detection of African horse sickness virus antibodies.

An indirect fluorescent antibody (IFA) technique was used to screen and quantify antibodies against African horse sickness virus (AHSV) in equine sera. Results obtained with the IFA assay were compared directly with those obtained with standard complement fixation (CF) and virus neutralisation (VN) tests using horse sera from experimental studies and samples from the field. Positive fluorescent antibody titres were detected from as early as 7 days after primary vaccination and persisted for at least six months. The IFA technique offers a clear advantage over CF tests, where the antibodies are often of shorter duration and where sera from donkeys and mules are frequently anticomplementary. The sensitivity and specificity of the IFA test compared with the VN test were 98% and 83.3%, respectively. The IFA test is rapid, relatively easy to perform and inexpensive, and can be recommended as an alternative assay for screening different species of equidae in AHSV control and surveillance programmes.

The effect of strategic anthelmintic treatment on the breeding performance and survival of ewes naturally infected with gastro-intestinal strongyles and protostrongylids.

In two trials, batches of ewes naturally infected with gastro-intestinal strongyles and protostrongylids (small lungworms) were treated with fenbendazole (10 mg/kg body weight) and morantel tartrate (8 mg/kg body weight) at strategic periods. In the first trial, treatment with fenbendazole during midgestation and early lactation, reduced miscarriages, stillbirths, mortality of ewes and their offspring. In the second trial, batches of ewes were treated wither with fenbendazole or with morantel tartrate or a combination of both at different strategic periods. In all the treated groups there were reductions in the mortality of ewes and their offspring which varied according to the regime of treatment and the nature of the anthelmintic used. The excessive mortality related to the presence of these parasites was 3.62% in ewes and 13.8 in lambs. For the former, Protostrongylids and gastro-intestinal strongyles played an equal role; Protostrongylids of ewes were the main cause of worm-induced mortality for the latter. The reduction in the output of strongyle eggs and lungworm larvae paralleled the breeding performance and mortality rate of animals.