A 47,XXY fetus conceived after ICSI of spermatozoa from a patient with non-mosaic Klinefelter's syndrome: case report

The birth of 12 healthy infants to fathers with non-mosaic Klinefelter's syndrome has been reported so far. The spermatozoa for these pregnancies was obtained from frozen-thawed ejaculate in one pregnancy (twins) and from the testis in the remaining 10 infants. All of them had a normal karyotype. We describe a patient with non-mosaic Klinefelter's syndrome from whom a testicular biopsy was obtained and motile spermatozoa were collected. Of 16 oocytes that were injected, 14 fertilized and cleaved. Three embryos were transferred, resulting in a triplet pregnancy. Karyotype analysis from chorionic villous sampling revealed 46,XX, 46,XY and 46,XXY from the three fetuses. The affected 46,XXY fetus was reduced on the 14th gestational week. The pregnancy culminated with the birth of a healthy male and female, on the 36th gestational week, weighing 3600 and 2660 g respectively. This case report proves the presence of hyperploid spermatozoa in the seminiferous lumen, and strengthens the necessity of genetic diagnosis of the embryos or fetuses in such pregnancies to fathers with non-mosaic Klinefelter's syndrome.     

Identification of antigens of Onchocerca volvulus and Onchocerca gibsoni for diagnostic use

Adults of Onchocerca volvulus and Onchocerca gibsoni were identically fractionated into a surface-enriched fraction, a phosphate buffered saline (PBS) extract and a PBS insoluble-detergent soluble fraction. Glycoproteins were prepared from these extracts and all fractions were examined by the Western blot technique using sera from individuals infected with a variety of filarial and non-filarial nematode worms. Using antisera to O. volvulus, a number of antigens were demonstrated in all of the extracts, with some antigens of each extract being unique. Many antigens were glycoproteins, and a high cross-reactivity was observed between O. volvulus and O. gibsoni. The different fractions of both species were also analysed using a panel of different sera in order to identify Onchocerca-specific antigens. The studies revealed that the lower molecular weight antigens showed greater Onchocerca specificity in all of the extracts examined. The surface-enriched fraction, however, clearly contained less widely cross-reacting components than the somatic and glycoprotein fractions. Finally, using surface labelling and coprecipitation techniques, O. gibsoni was shown to possess a 20 kDa Onchocerca-specific antigen, previously described for O. volvulus. The findings indicate a number of Onchocerca-specific antigens which may have potential in diagnosis of human onchocerciasis. They also show that the related bovine parasite O. gibsoni, may be an alternative source of material.     

Evidence for high seroprevalence of Taenia solium cysticercosis in individuals from three rural communities in Venezuela

A serological study was undertaken in 1998 to evaluate levels of Taenia solium cysticercosis in 3 rural Venezuelan communities. Infection with viable metacestodes was diagnosed with a trapping enzyme-linked immunosorbent assay (ELISA) that detects a secreted product of viable parasites. Anti-metacestode antibodies were assayed by ELISA using T. solium vesicular fluid as antigen. A total of 1254 sera was collected from 3 communities (Canoabo, Sanare, and Rio Tocuyo) where previous studies had suggested the presence of T. solium. Our results demonstrate an unusually high seroprevalence of cysticercosis, indicating an attendant risk of transmitting the disease to other areas. The seroprevalence of infection with viable cysts, as indicated by detection of circulating parasite antigen, was 9.1% in Canoabo, 6.1% in Sanare, and 5.7% in Rio Tocuyo. The corresponding frequency of antibodies to T. solium cyst antigens was 36.5% in Canoabo, 36.5% in Sanare, and 4% in Rio Tocuyo. As these communities are probably representative of many others in Venezuela, T. solium cysticercosis may be a significant public health problem and more work is certainly indicated. An important finding was that local knowledge of the disease and its transmission do not necessarily guarantee diminished disease prevalence, indicating a lack of appropriate vigilance towards disease control.     

Lead exposure in day care centres in the Caracas Valley--Venezuela

Lead has been used as an additive to improve the anti-knock quality of gasoline. However, the combustion of lead gasoline produces particles rich in this element. These kinds of particles impact the alveoli and move into the bloodstream, causing serious health problems. The objective of this study is to determine the granulometric distribution, mineralogy, and lead levels in samples such as settled dust and soil, as well as lead concentration in drinking water, in different day care centers located in the metropolitan area of Caracas, which have been previously studied and classified, according to the Total Suspended Particles (TSP) levels by the national environmental office, as high (80 microg m(-3)) and low (50 microg m(-3)) polluted areas. The chemical analysis was performed by atomic absorption spectroscopy and atomic emission spectroscopy-inductively coupled plasma. The mineralogy was determined using X-ray differentiation. Results show that all samples are enriched by small particles (<44 microm). Lead concentrations in day care centres located in areas of high vehicular density were higher than those in areas of low vehicular traffic. Lead concentration for drinking water samples was below the standard value reported by the Environmental Protection Agency (EPA) (15 microg Pb/l).     

Exercise and tachycardia increase NADPH oxidase and ryanodine receptor-2 activity: possible role in cardioprotection

AIM: Our objective was to investigate in cardiac muscle the contribution of NADPH oxidase to (a) ryanodine receptor-2 (RyR2) S-glutathionylation and (b) the preconditioning effects of exercise and tachycardia on infarct size following coronary artery occlusion. METHODS AND RESULTS: We measured NADPH oxidase activity, RyR2 S-glutathionylation, and calcium release kinetics in sarcoplasmic reticulum (SR) vesicles isolated from dog ventricular muscle after exercise and tachycardia, plus or minus prior administration of the NADPH oxidase inhibitor apocynin. In ventricular muscle sections, we studied the colocalization of NADPH oxidase and RyR2 by confocal microscopy using fluorescent antibodies. We determined the effect of apocynin on the infarct size produced by occlusion of the descendent anterior coronary artery in animals preconditioned by exercise or tachycardia. Exercise and tachycardia increased NADPH oxidase activity, RyR2 S-glutathionylation, and calcium release rates in isolated SR vesicles. Cardiac muscle sections displayed significant colocalization of NADPH oxidase and RyR2, suggesting direct and specific effects of reactive oxygen species (ROS) produced by NADPH oxidase on RyR2 activation. The NADPH oxidase inhibitor apocynin prevented the increase in RyR2 S-glutathionylation, reduced calcium release activity, and completely prevented the protective effects of exercise and tachycardia on infarct size. CONCLUSIONS: The loss of cardioprotection induced by the NADPH oxidase inhibitor suggests that ROS generated by this enzyme are important mediators of the preconditioning response, which presumably involves NADPH oxidase-induced RyR2 S-glutathionylation.     

In Vivo Measurements of Cortical Thickness and Porosity at the Proximal Third of the Tibia Using Guided Waves: Comparison with Site-Matched Peripheral Quantitative Computed Tomography and Distal High-Resolution Peripheral Quantitative Computed Tomography

The aim of this study was to estimate cortical porosity (Ct.Po) and cortical thickness (Ct.Th) using 500-kHz bi-directional axial transmission (AT). Ct.Th_AT and Ct.Po_AT were obtained at the tibia in 15 patients from a 2-D transverse isotropic free plate model fitted to measured guided wave dispersion curves. The velocities of the first arriving signal (υ_FAS) and A₀ mode (υ_A0) were also determined. Site-matched peripheral quantitative computed tomography (pQCT) provided volumetric cortical bone mineral density (Ct.vBMD_pQCT) and Ct.Th_pQCT. Good agreement was found between Ct.Th_AT and Ct.Th_pQCT (R²?=?0.62, root mean square error [RMSE]?=?0.39 mm). Ct.vBMD_pQCT correlated with Ct.Po_AT (R²?=?0.57), υ_FAS (R²?=?0.43) and υ_A0 (R²?=?0.28). Furthermore, a significant correlation was found between AT and distal high-resolution pQCT. The measurement ofcortical parameters at the tibia using guided waves might improve the prediction of bone fractures in a cost-effective and radiation-free manner.     

Tachycardia increases NADPH oxidase activity and RyR2 S-glutathionylation in ventricular muscle

We have shown previously that electrically induced tachycardia effectively produces myocardial preconditioning. Among other effects, tachycardia increases calcium release rates in microsomal fractions enriched in sarcoplasmic reticulum (SR) isolated from dog cardiac ventricular muscle. Here, we report that preconditioning tachycardia increased twofold the NADPH oxidase activity of isolated SR-enriched microsomal fractions, measured as NADPH-dependent generation of superoxide anion and hydrogen peroxide. Tachycardia also augmented the association of rac1 and the NADPH oxidase cytosolic subunit p47(phox) to the microsomal fraction, without modifying the content of the membrane integral subunit gp91(phox). Microsomes from control animals displayed endogenous S-glutathionylation of cardiac ryanodine receptors (RyR2); in microsomal fractions isolated after tachycardia RyR2 S-glutathionylation levels were 1.7-fold higher than in controls. Parallel in vitro experiments showed that NADPH produced a transient increase in calcium release rates and enhanced 1.6-fold RyR2 S-glutathionylation in control microsomes but had marginal or no effects on microsomes isolated after tachycardia. Catalase plus superoxide dismutase, and the NADPH oxidase inhibitors apocynin and diphenyleneiodonium prevented the in vitro stimulation of calcium release rates and RyR2 S-glutathionylation induced by NADPH, suggesting NADPH oxidase involvement. Conversely, addition of reducing agents to vesicles incubated with NADPH markedly inhibited calcium release and prevented RyR2 S-glutathionylation. We propose that tachycardia stimulates NADPH oxidase activity, which by enhancing RyR2 redox modifications such as S-glutathionylation, would contribute to sustain faster calcium release rates during conditions of increased cardiac activity. This response may be an important component of tachycardia-induced preconditioning.     

Identification of HLA-A2 restricted CD8(+) T-lymphocyte responses to Plasmodium vivax circumsporozoite protein in individuals naturally exposed to malaria

Specific CD8(-) T-lymphocyte (CTL) activity against Plasmodium pre-erythrocytic stages (P-ES) derived antigens is considered one of the most important mechanisms for malaria protection. Plasmodium vivax is the second most prevalent human malaria parasite species distributed worldwide. Although several CTL epitopes have been identified in Plasmodium falciparum P-ES derived antigens, none has been described for P. vivax to date. In this study, we analysed HLA-A*0201 specific CD8(-) T-lymphocyte responses to the P. vivax circumsporozoite (CS) protein in both malaria exposed and non-exposed populations from the Colombian Pacific Coast. First, we analysed the prevalence of HLA-A2 allele in the study populations and found that approximately 38 of the individuals expressed this molecule and that 50 of them were HLA-A*0201. We then selected, on the P. vivax CS, five peptide sequences containing the HLA-A*0201 binding motifs and used the corresponding synthetic peptides to evaluate the CD8(-) T-lymphocyte interferon (IFN)-gamma response. Peripheral blood mononuclear cells from the HLA-A*0201 donors were in vitro stimulated with these peptides and IFN-gamma production was determined by an ELISPOT assay. Specific CD8(-) T-lymphocyte responses were detected for three peptides located in the C-terminal region of the protein. Specific responses to these peptides were also detected in several individuals expressing different HLA-A*02 subtypes. The potential of these peptides to induce specific cytolysis and that of long synthetic peptides comprising these epitopes as P. vivax malaria vaccine subunits are being studied.     

The clinical application of spectral karyotyping (SKY) in the analysis of prenatally diagnosed extra structurally abnormal chromosomes (ESACs)

OBJECTIVE: The prenatal detection of de novo extra structurally abnormal chromosomes (ESACs) presents a challenge because the associated risk for congenital anomaly ranges from 100% to practically none, depending on the chromosomal origin. Despite the use of standard cytogenetic techniques and even fluorescence in situ hybridization (FISH), the origin of some ESACs often remains elusive. Spectral karyotyping (SKY) is a molecular cytogenetic technique based on the simultaneous analysis of all chromosomes using a unique probe mix that allows the rapid identification of all chromosomes in 24 colors. The purpose of this study was to evaluate the use of SKY in the characterization of prenatally diagnosed de novo ESACs. METHODS: This series includes five cases of de novo ESACs detected prenatally in routine amniocentesis samples performed for advanced maternal age. Cases of inherited ESACs or ESACs defined by standard cytogenetic techniques were excluded. RESULTS: SKY analysis yielded valuable information, particularly in cases of nonsatellited ESACs: a der(18) and a ring(Y). In a case of a unisatellited der(15), SKY corroborated data obtained by standard cytogenetic techniques and FISH. Finally, in two cases of small bisatellited chromosomes, SKY was noncontributory. CONCLUSIONS: While SKY may be a valuable tool in some cases, especially nonsatellited and ring ESACs, it does have limitations and should be used judiciously in conjunction with other cytogenetic techniques.     

Prenatal diagnosis of Down syndrome: ten year experience in the Israeli population

Second trimester maternal serum biochemical markers, introduced between 1990 and 1995, were supplemented with new ultrasound methods at 14-16 weeks and first trimester biochemical markers between 1995 and 2000. This study evaluated the effectiveness of a Down syndrome (DS) prevention program among the Israeli Jewish population between 1990 and 2000. We collected data on the total number of prenatal tests performed on Israeli Jewish women, DS cases detected prenatally and DS livebirths in Israel during these years. We also studied the use of the newer screening tests in 1990, 1992, and 2000. Between 1990 and 1995, use of chromosomal studies for DS in this population increased from 11.3% to 21.6% and the percentage of cases detected prenatally from 53% to 70%. However, between 1996 and 2000, even with the new screening methods, the utilization rate remained similar (20.7% and 19.8%, respectively) and the percentage detected prenatally decreased to 61% in 2000. The total cost per case detected increased from $47,971 US dollars in 1990 to $75,229 US dollars in 1992, and to $190,171 US dollars in 2000. Between 1990 and 1995, improvement in the percentage of cases detected prenatally was associated with a significant increase in the amniocentesis rate-both are attributed to the introduction of second trimester maternal serum biochemical marker tests. Unexpectedly, the introduction between 1995 and 2000 of new genetic methods to assess the DS risk did not improve the percentage detected or reduce the amniocentesis rate, and was accompanied by an increased cost per case detected.