Induction of haem oxygenase‐1 increases infection of dog macrophages by L. infantum

We aimed to induce and inhibit HO‐1, ascertaining its effect on infection rate, parasite load and the levels of superoxide, reactive oxygen species (ROS), nitric oxide (NO), TNF‐alpha and IL‐10 in cultured macrophages from healthy dogs infected by Leishmania infantum. Macrophages obtained from 15 healthy dogs were cultured alone or infected with L. infantum, with or without association of HO‐1 inducer and inhibitor. The infection rate and the parasite load were determined by the number of infected macrophages and number of promastigotes per macrophage, respectively. HO‐1 levels and gene expression, as well as IL‐10 and TNF‐alpha levels were also measured in these cultures. Superoxide, ROS and NO levels in macrophages were measured through flow cytometry. Induction of HO‐1 increased the infection rate and parasite load, while its inhibition decreased the infection rate and IL‐10 production. There was a positive correlation between HO‐1 and infection rate or parasite load. Increased infection rate was associated with decreased superoxide, ROS and NO levels. Induction of HO‐1 metabolism in dogs infected by L. infantum is possibly one of the mechanisms responsible for increasing the infection of macrophages, mainly through reduction in the oxidative and nitrosative metabolisms of these cells.     

Evaluation of BRCA1 and BRCA2 mutations and risk-prediction models in a typical Asian country (Malaysia) with a relatively low incidence of breast cancer

Introduction

The cost of genetic testing and the limited knowledge about the BRCA1 and BRCA2 genes in different ethnic groups has limited its availability in medium- and low-resource countries, including Malaysia. In addition, the applicability of many risk-assessment tools, such as the Manchester Scoring System and BOADICEA (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm) which were developed based on mutation rates observed primarily in Caucasian populations using data from multiplex families, and in populations where the rate of breast cancer is higher, has not been widely tested in Asia or in Asians living elsewhere. Here, we report the results of genetic testing for mutations in the BRCA1 or BRCA2 genes in a series of families with breast cancer in the multi-ethnic population (Malay, Chinese and Indian) of Malaysia.

Method

A total of 187 breast cancer patients with either early-onset breast cancer (at age ≤ 40 years) or a personal and/or family history of breast or ovarian cancer were comprehensively tested by full sequencing of both BRCA1 and BRCA2. Two algorithms to predict the presence of mutations, the Manchester Scoring System and BOADICEA, were evaluated.

Results

Twenty-seven deleterious mutations were detected (14 in BRCA1 and 13 in BRCA2), only one of which was found in two unrelated individuals (BRCA2 490 delCT). In addition, 47 variants of uncertain clinical significance were identified (16 in BRCA1 and 31 in BRCA2). Notably, many mutations are novel (13 of the 30 BRCA1 mutations and 24 of the 44 BRCA2). We report that while there were an equal proportion of BRCA1 and BRCA2 mutations in the Chinese population in our study, there were significantly more BRCA2 mutations among the Malays. In addition, we show that the predictive power of the BOADICEA risk-prediction model and the Manchester Scoring System was significantly better for BRCA1 than BRCA2, but that the overall sensitivity, specificity and positive-predictive value was lower in this population than has been previously reported in Caucasian populations.

Conclusion

Our study underscores the need for larger collaborative studies among non-Caucasian populations to validate the role of genetic testing and the use of risk-prediction models in ensuring that the other populations in the world may also benefit from the genomics and genetics era.     

Congenital mesoblastic nephroma: Other magnetic resonance imaging findings

Congenital mesoblastic nephroma (CMN) is a rare renal tumour usually imaged by ultrasound and or CT. To the authors’ knowledge there have been only two previous reports concerning MR imaging of CMN in the English-speaking literature. The MRI findings in a neonate with CMN, which were not previously described, are reported here.     

The antiepileptic activity of JSTX-3 is mediated by N-methyl-D-aspartate receptors in human hippocampal neurons

We analyzed the effect of the acylpolyaminetoxin JSTX-3 on the epileptogenic discharges induced by perfusion of human hippocampal slices with artificial cerebrospinal fluid lacking Mg2+ or N-methyl-D-aspartate. Hippocampi were surgically removed from patients with refractory medial temporal lobe epilepsy, sliced in the surgical room and taken to the laboratory immersed in normal artificial cerebrospinal fluid. Epileptiform activity was induced by perfusion with Mg2+-free artificial cerebrospinal fluid or by iontophoretically applied N-methyl-D-aspartate and intracellular and field recordings of CA1 neurons were performed. The ictal-like discharges induced by Mg2+-free artificial cerebrospinal fluid and N-methyl-D-aspartate were blocked by incubation with JSTX-3. This effect was similar to that obtained with the N-methyl-D-aspartate receptor antagonist DL (-)2-amino-5 phosphonovaleric acid. Our findings suggest that in human hippocampal neurons, the antiepileptic effect of JSTX-3 is mediated by its action on N-methyl-D-aspartate receptor.     

Evaluation of stimulus-induced acrosome reaction by two-colour flow cytometric analysis

Acrosome status in human spermatozoa from 20 normozoospermic men was evaluated by flow cytometry following the induction of the acrosome reaction with the ionophore A23187. Dual fluorescence staining of methanol fixed spermatozoa incubated with and without (control) the ionophore A23187 was performed with probes which targeted the outer acrosomal membrane (OAM) (rhodamine-labelled Arachis hypogaea agglutinin) or constituents of the acrosomal vesicle (fluorescein- labelled Pisum sativum agglutinin). Flow cytometry analysis revealed two major subpopulations of cells: acrosome-intact and acrosome-reacted spermatozoa after induction of the acrosome reaction. The intensity of green and red fluorescence in acrosome-reacted spermatozoa was significantly lower than that of the acrosome-intact control spermatozoa (P < 0.0001). The intensity of green fluorescence in the acrosome-intact subpopulation of spermatozoa was significantly higher than that of the control population (P < 0.002). Exposure of spermatozoa to the ionophore A23187 resulted in reliable enhancement of the number of spermatozoa with very high intensity of green and/or red fluorescence compared with the control (P < 0.03). An inverse correlation between the number of acrosome-reacted spermatozoa and spermatozoa with a very high intensity of green and/or red fluorescence was demonstrated (r = -0.631, P < 0.01). This method provides an objective and efficient procedure for quantitative estimation of the acrosomal status of human spermatozoa.