Deletion mapping of chromosome 17 in benign and malignant adrenocortical tumors associated with the Arg337His mutation of the p53 tumor suppressor protein

The human p53 tumor suppressor gene is located at the short arm of chromosome 17. A germinative mutation (Arg337His) in the tetramerization domain of p53 has been frequently identified in Brazilian children with sporadic adrenocortical tumors. Loss of heterozygosity at this region was demonstrated in the majority of the cases. In the present study, we performed deletion mapping of chromosome 17 in 30 adrenocortical tumors from 29 Brazilian patients (15 children and 14 adults). One boy had bilateral adrenocortical tumor. Sixteen patients had the germinative Arg337His mutation. Loss of heterozygosity analysis using six polymorphic microsatellite markers disclosed loss of the entire chromosome 17 in 18 tumors (10 adenomas and eight carcinomas) from 17 patients. The Arg337His mutation was present in 13 of them. Chromosomal instability involving chromosomes 2, 9, and 11 was also found in 47, 47, and 70% of the 17 patients who exhibited chromosome 17 losses, respectively. The concomitant loss of chromosomes 2, 9, 11, and 17 was evidenced exclusively in malignant tumors. Therefore, chromosomal instability involving three or more chromosomes may contribute to define the malignant adrenocortical lesions. In conclusion, we demonstrated a high frequency of biallelic inactivation of p53 derived from two distinct events, the germinative Arg337His mutation and the acquired loss of the entire chromosome 17. In addition, the isolated loss of the entire chromosome 17 did not correlate with aggressive tumor behavior in these patients with adrenocortical tumors.     

The <Emphasis Type="Italic">NLRP3</Emphasis> and <Emphasis Type="Italic">CASP1</Emphasis> gene polymorphisms are associated with developing of acute coronary syndrome: a case-control study

The protein products of NLRP3 and CASP1 genes are involved in the cleavage of pro-IL-1B and pro-IL-18 leading to the active cytokines, which play an important role in the development of the acute coronary syndrome (ACS). The aim of the present study was to evaluate whether NLRP3 and CASP1 gene polymorphisms are biomarkers of ACS susceptibility in Mexican population. Two polymorphisms of the CASP1 gene [G+7/in6A (rs501192) and A10370-G Exon-6 (rs580253)] and one of the NLRP3 gene [UTR′3 G37562-C (rs10754558)] were genotyped by 5′ exonuclease TaqMan assays in a group of 617 patients with ACS and 609 control individuals. Under recessive model, the CASP1 G+7/in6A polymorphism was associated with an increased risk of developing ACS when compared to healthy controls (OR = 1.76, 95% CI 1.08–2.86, P _Res  = 0.022). In the same way, under recessive model, the CASP1 A10370-G was associated with increased risk of ACS (OR = 1.75, 95% CI 1.07–2.85, P _Res  = 0.025). Moreover, under co-dominant, dominant, over-dominant, and additive models, the NLRP3 UTR′3 G37562-C was associated with a decreased risk of ACS (OR = 0.45, 95%CI 0.22–0.92, P _Co-dom  = 0.006; OR = 0.61, 95%CI 0.44–0.84, P _Dom  = 0.002; OR = 0.67, 95%CI 0.48–0.94, P _Over-dom  = 0.02; and OR = 0.65, 95%CI 0.50–0.94, P _Add  = 0.02, respectively). In summary, this study demonstrates that the G+7/in6A and A10370-G polymorphisms of the CASP1 gene are associated with increased risk of developing ACS, whereas the UTR′3 G37562-C polymorphism of the NLRP3 gene is associated with a decreased risk of developing ACS in Mexican population.     

Human and porcine neurocysticercosis: differences in the distribution and developmental stages of cysticerci

Objective To describe and compare the clinical impacts of neurocysticercosis (NC) caused by Taenia solium in humans and pigs. Methods Comparative study of the brains of 16 asymptomatic pigs and 35 human NC cases (15 asymptomatic and 20 symptomatic). Results In humans, cysticerci were more frequently located in the ventricles and subarachnoid space at the base of the brain (11.8%vs. 1.6%; P = 0.001 and 25.9%vs. 0%; P < 0.0001, respectively) while in pigs, cysticerci were more frequently found in the parenchyma (44.4%vs. 7.6%; P < 0.0001). In human brains, 75.9% of the cysticerci were calcified, while in pigs all cysticerci were in the vesicular stage. Conclusion The duration of infection and the host–parasite relationship (such as immune reactivity and brain haemodynamics) differ between humans and pigs. This may account for the different distribution and stage of the cysticerci among humans and pigs.     

A general method for estimating deformation and forces imposed in vivo on bioprosthetic heart valves with flexible annuli: in vitro and animal validation studies

BACKGROUND AND AIM OF THE STUDY: The use of flexible structures within cardiovascular prostheses such as valves, stents and vascular grafts has been proposed as a means of more closely modeling native mechanics, and thereby reducing the biomechanical problems associated with rigid materials. However, the design of such materials has been hampered by the paucity of quantitative information on the in-vivo behavior of such structures. The aim of this study was to explore the use of 3D ultrasound imaging coupled with finite element analysis (FEA) as a tool to estimate deformation and forces imposed in vivo on a novel bioprosthetic valve design. METHODS: The method was first tested using in-vitro static loading conditions, where good agreement between displacements seen on video and those obtained from application of the identical force within the finite element program was seen. The method was then tested in a porcine model with valves implanted in the mitral position. Images of the deforming annular ring were obtained over the cardiac cycle using 3D intravascular ultrasound; these images were fed into the FEA program for calculation of reaction forces. RESULTS: Results in vitro showed that a force of 2.7-8.0 Newtons (N) was required to produce a deformation of between 1.0 and 3.0 mm in the radial direction. A time history of deformation and force around the ring of the valve stent could be obtained for the in-vivo conditions. These results revealed a maximum deformation of 0.5-1.7 mm along the short axis (anteroposterior) of the mitral valve. Coupled to this, a peak reaction force of 4.4-13.9 N was found at the points corresponding to maximal deflection. Both deformation and reaction force reached maximum during atrial contraction. CONCLUSION: This method provides an accurate means of estimating deformation and corresponding forces imposed in vivo on intracardiac prostheses. The results provide information on the dynamic behavior of the mitral valve annulus. Such information should be useful in the design of flexible cardiovascular prostheses.     

Activity of the Na,K-ATPase α4 Isoform Is Regulated During Sperm Capacitation to Support Sperm Motility

The α4 polypeptide is a testis-specific isoform of the catalytic subunit of the Na,K-ATPase, which is essential for sperm motility and fertility. In the present study, we have investigated the regulation of activity of the α4 isoform and the relevance of this event for sperm capacitation. We have performed this by taking advantage of the selective high affinity of α4 for the inhibitor ouabain. Our results show that ouabain-sensitive hydrolysis of ATP and uptake of (86)Rb, corresponding to the enzymatic and ion transport activities of α4, respectively, increased during sperm capacitation in a time-dependent manner. Specific labeling of α4 with the fluorescent indicator bodipy-ouabain and immunoblot analysis of biotinylated and streptavidin-precipitated sperm plasma membrane proteins indicated a capacitation- and time-dependent rise in levels of active α4 isoform at the sperm surface. Ouabain inhibition of α4 blocked the increase in total sperm motility and the hyperactive motility pattern characteristic of sperm capacitation. Moreover, interference of α4 activity with ouabain partially prevented the intracellular decrease in Na(+) and the plasma membrane hyperpolarization that typically accompany sperm capacitation. In contrast, ouabain inhibition of α4 did not affect the spontaneous sperm acrosomal reaction following capacitation. Together, these results demonstrate that Na,K-ATPase α4 activity is up-regulated during sperm capacitation through mechanisms that involve both increases in molecular activity and levels of α4 at the sperm plasma membrane. This increase in α4 activity helps maintain the changes in motility that are associated with sperm capacitation, emphasizing the biologic relevance of the Na,K-ATPase α4 isoform in sustaining sperm function.     

Association of the Transmembrane Serine Protease-2 (TMPRSS2) Polymorphisms with COVID-19

SARS-CoV-2 uses the ACE2 receptor and the cellular protease TMPRSS2 for entry into target cells. The present study aimed to establish if the TMPRSS2 polymorphisms are associated with COVID-19 disease. The study included 609 patients with COVID-19 confirmed by RT-PCR test and 291 individuals negative for the SARS-CoV-2 infection confirmed by RT-PCR test and without antibodies anti-SARS-CoV-2. Four TMPRSS2 polymorphisms (rs12329760, rs2298659, rs456298, and rs462574) were determined using the 5′exonuclease TaqMan assays. Under different inheritance models, the rs2298659 (p_codominant2 = 0.018, p_recessive = 0.006, p_additive = 0.019), rs456298 (p_codominant1 = 0.014, p_codominant2 = 0.004; p_dominant = 0.009, p_recessive = 0.004, p_additive = 0.0009), and rs462574 (p_codominant1 = 0.017, p_codominant2 = 0.004, p_dominant = 0.041, p_recessive = 0.002, p_additive = 0.003) polymorphisms were associated with high risk of developing COVID-19. Two risks (ATGC and GAAC) and two protectives (GAGC and GAGT) haplotypes were detected. High levels of lactic acid dehydrogenase (LDH) were observed in patients with the rs462574AA and rs456298TT genotypes (p = 0.005 and p = 0.020, respectively), whereas, high heart rate was present in patients with the rs462574AA genotype (p = 0.028). Our data suggest that the rs2298659, rs456298, and rs462574 polymorphisms independently and as haplotypes are associated with the risk of COVID-19. The rs456298 and rs462574 genotypes are related to high levels of LDH and heart rate.     

Immunoenzymatic assay that measures the expression of murine histocompatibility antigens in macrophages and lymphocytes

A convenient—simple, sensitive, rapid and reproducible—enzyme immunoassay to measure H-2 particulated and solubilized cellular antigens is described. Cellular antigens were measured by ELISA through the binding of specific biotinylated antibodies and streptoavidin-peroxidase conjugate to cells in suspension. Endogenous peroxidase activity of activated cells was inhibited by addition of sodium azide and H₂O₂ in acid conditions. The assay proved capable of distinguishing between two cell lines (EL–4/H–2^b and P815/H–2^d) and even between the cells of three congenic mouse strains (BALB/B, H–2^b, BALB/c, H–2^d, and BALB/K, H-2^k) and was sensitive to as few as 2.5 × 10⁴ cells/well. Results were comparable to those obtained with FACS. An inhibition version of this assay was found to be very useful for the detection of H–2 antigens present in whole antigen cells extracts. © 1993 Wiley-Liss, Inc.