Phosphorylation and ubiquitination are necessary for Na,K-ATPase endocytosis during hypoxia

As a cellular adaptative response, hypoxia decreases Na,K-ATPase activity by triggering the endocytosis of its alpha(1) subunit in alveolar epithelial cells. Here, we present evidence that the ubiquitin conjugating system is important in the Na,K-ATPase endocytosis during hypoxia and that ubiquitination of Na,K-ATPase alpha(1) subunit occurs at the basolateral membrane. Endocytosis and ubiquitination were prevented when the Ser 18 in the PKC phosphorylation motif of the Na,K-ATPase alpha(1) subunit was mutated to an alanine, suggesting that phosphorylation at Ser-18 is required for ubiquitination. Mutation of the four lysines surrounding Ser 18 to arginine prevented Na,K-ATPase ubiquitination and endocytosis during hypoxia; however, only one of them was sufficient to restore hypoxia-induced endocytosis. We provide evidence that ubiquitination plays an important role in cellular adaptation to hypoxia by regulating Na,K-ATPase alpha(1)-subunit endocytosis.     

Left ventricular geometric patterns in newly presenting nigerian hypertensives: An echocardiographic study

Background

In recent years a number of algorithms for cardiovascular risk assessment has been proposed to the medical community. These algorithms consider a number of variables and express their results as the percentage risk of developing a major fatal or non-fatal cardiovascular event in the following 10 to 20 years

Discussion

The author has identified three major pitfalls of these algorithms, linked to the limitation of the classical statistical approach in dealing with this kind of non linear and complex information. The pitfalls are the inability to capture the disease complexity, the inability to capture process dynamics, and the wide confidence interval of individual risk assessment. Artificial Intelligence tools can provide potential advantage in trying to overcome these limitations. The theoretical background and some application examples related to artificial neural networks and fuzzy logic have been reviewed and discussed.

Summary

The use of predictive algorithms to assess individual absolute risk of cardiovascular future events is currently hampered by methodological and mathematical flaws. The use of newer approaches, such as fuzzy logic and artificial neural networks, linked to artificial intelligence, seems to better address both the challenge of increasing complexity resulting from a correlation between predisposing factors, data on the occurrence of cardiovascular events, and the prediction of future events on an individual level.     

Experience in northern Nigeria with countercurrent immunoelectrophoresis, double diffusion and indirect haemagglutination tests for diagnosis of hydatid cyst in camels

Sera from 36 slaughtered camels with proven hydatid disease, from 46 camels found to be free of hydatidosis at post-mortem meat inspection, and from 26 animals with confirmed caprine heartwater, bovine trypanosomiasis and cysticercosis were examined. The indirect haemagglutination was found to be the most sensitive but least specific of the three tests. Ouchterlony's double diffusion (DD) test was specific and fairly sensitive. Although the countercurrent immunoelectrophoresis was as specific as DD, it was the least sensitive of the three serological tests. All three serological tests were always positive in camels with hydatid cyst infection affecting both the liver and the lung. A combination of indirect haemagglutination and Ouchterlony's double diffusion test could be useful for diagnosing hydatidosis in camels and probably other animals.     

Prevalence of Toxocara spp. eggs in some public grounds and highway rest areas in Kansas.

Out of a total of 282 soil samples obtained from public areas, 58 samples contained Toxocara spp. eggs. This gave an overall prevalence of 20.6%. Highway rest areas were contaminated and childrens sand boxes had the highest percentage of recovery of all.     

Yq microdeletions--azoospermia factor candidate genes and spermatogenic arrest.

In the last few years considerable progress has been made in the study of sperm physiology and the biology of gamete interaction, furthering our understanding of the pathophysiology of male infertility. With the advent of assisted reproductive technology and intracytoplasmic sperm injection, study of the various factors leading to spermatogenic impairment has become a major focus of scientific research. Understanding the genetic factors that lead to infertility has taken on a certain urgency, as we have learned not only of the transmission to male offspring of spermatogenic impairment, but that these offspring may also be born with a secondary, larger deletion with worsening of phenotype and genital ambiguity.Ten to twenty-five percent of couples encounter difficulty procreating. Microdeletions of the long arm of the Y chromosome are associated with spermatogenic failure and have been used to define three regions on Yq (AZFa, AZFb, and AZFc) that are critical for spermatogenesis. This study was conceived in order to identify the frequency of submicroscopic interstitial deletions in azoospermia factor loci in infertile Indian males. One hundred and seventy five males with nonobstructive oligozoospermia and azoospermia were included in this study. Semen analysis was done in each case to determine the spermatogenic status-normospermic, oligozoospermic (< 20 million sperm/mL), or azoospermic (no sperm in the semen). Detailed medical, clinical, reproductive, and family histories were taken of each patient. Thirty G-banded metaphases were analyzed in each case and polymerase chain reaction microdeletion analysis was done in 133 cytogenetically normal cases. For this genomic, DNA was extracted using peripheral blood. The sequence tagged site primers tested in each case were sY84, sY86 (AZFa); sY113, sY116, sY127, sY134 (AZFb); sY254, sY255 (AZFc). Polymerase chain reaction amplifications found to be negative were repeated at least three times to confirm the deletion of a given marker. The polymerase chain reaction products were analyzed on a 1.8% agarose gel. Eight of the 133 cases showed deletion of at least one of the sequence tagged site markers. Review of the literature has shown that the overall frequency of microdeletions varies from 1% to 55%. In the present study the frequency of microdeletion was 6.01%. Deletions were detected in cases with known and unknown etiology with bilateral severe testiculopathy.     

Mitochondrial DNA variations in ova and blastocyst: Implications in assisted reproduction

Mitochondrial DNA (mtDNA) of oocyte is critical for its function, embryo quality and development. Analysis of complete mtDNA of 49 oocytes and 18 blastocysts from 67 females opting for IVF revealed 437 nucleotide variations. 40.29% samples had either disease associated or non-synonymous novel or pathogenic mutation in evolutionarily conserved regions. Samples with disease associated mtDNA mutations had low fertilization rate and poor embryo quality, however no difference in implantation or clinical pregnancy rate was observed. Screening mtDNA from oocyte/blastocyst is a simple, clinically reliable method for diagnostic evaluation of female infertility and may reduce risk of mtDNA disease transmission.     

A new technique for the recovery of Toxocara eggs from soil.

A new flotation technique for the extraction of Toxocara eggs from soil has been devised. It has a fairly high recovery efficiency for Toxocara eggs, can be used for replicated quantitative experiments, and may also be used for recovery of other ascarid eggs from soil.     

Blockade of the selective increase in serum follicle-stimulating hormone concentration in immature female rats and its effects on ovarian follicular development

We investigated whether administration of monosodium L-glutamate (MSG) to neonatal female rats would block the selective increase in serum follicle-stimulating hormone (FSH) concentration in immature rats in an attempt to provide a model in which to study the importance of the selective FSH rise on ovarian follicular development. In two separate experiments, s.c. injections of MSG (4 mg/g BW) on Days 1, 3, 5, 7 and 9 after birth blocked the selective increase in serum FSH concentration observed on Days 7 and 15 without blocking basal FSH secretion. Serum luteinizing hormone (LH) levels were unaffected in the first experiment and changed little in the second. MSG-treated rats had smaller ovaries on Days 15 and 23. The ovaries of MSG-treated rats on Day 15 showed decreased follicular growth as evidenced by a decrease in the number and percentage of follicles with diameters greater than 50 microns, in the number of follicles with greater than 1 layer of granulosa cells, and in the number of follicles beyond the primary stage of follicular development. These differences between MSG-treated rats and controls all but disappeared by Day 23. The results demonstrate that neonatal administration of MSG blocks the selective increase in serum FSH concentration in immature female rats and suggest that this selective increase in serum FSH levels plays a role in the normal acceleration of ovarian follicular development but is not needed for the development of preovulatory follicles by the sixth week after birth.