Suggestive evidence of association of C-159T functional polymorphism of the <Emphasis Type="Italic">CD14</Emphasis> gene with atopic asthma in northern and northwestern Indian populations

CD14 is a lipopolysaccharide receptor known to be an important modulator of Th1–Th2 response during early childhood. Genetic association studies of the CD14 gene with asthma and atopic disorders have shown positive as well as negative results in different ethnic populations. The aim of this study was to test for association of C-159T functional promoter polymorphism with atopic asthma and serum IgE levels in northern and northwestern Indian populations. DNA was assayed for the CD14 C-159T polymorphism in a case-control study involving atopic asthmatics (n=187) and healthy normal controls (n=227), and in a family-based association study of 106 trios. The case-control study showed an association at the genotypic (P=0.0146) as well as the allelic level (P=0.0048). Moreover, we observed a deviation of allelic transmission from random proportions (P=0.024) in the transmission disequilibrium test analysis. When we analyzed our results for serum total IgE levels, against this polymorphism, we observed a difference at the genotypic (P=0.0026) as well as at the allelic level (P=0.0016) in a case-control study, whereas no association in the quantitative transmission disequilibrium test analysis was obtained. These findings provide suggestive evidence of association of the CD14 gene locus with atopic asthma in northern and northwestern Indian populations.     

Apoptosis of pancreatic acinar cells in acute pancreatitis: is it good or bad?

Acute pancreatitis is a disease of variable severity in which some patients experience mild, self-limited attacks while others manifest a severe, highly morbid, and frequently lethal attack. The events that regulate the severity of acute pancreatitis are, for the most part, unknown. Several recent studies have suggested that the acinar cell response to injury may be an important determinant of disease severity. In these studies, mild acute pancreatitis was found to be associated with extensive apoptotic acinar cell death while severe acute pancreatitis was found to involve extensive acinar cell necrosis but very little acinar cell apoptosis. These observations have led to the hypothesis that apoptosis might be a favorable response to acinar cell and that interventions which favor induction of apoptotic, as opposed to necrotic, acinar cell death might reduce the severity of an attack of acute pancreatitis. This review aims to discuss our current understanding of the contribution of acinar cell apoptosis to the severity of acute pancreatitis.     

Proteomic analysis of selected prognostic factors of breast cancer

The incidence of breast cancer is on the rise but as yet there is no guaranteed beneficial treatment for many of the sufferers. The treatments specific for breast and other hormone-sensitive cancers work well at times, however, the population of women that they will benefit is relatively small. Many are limited to surgical, chemotherapy, and radiotherapy options. Here, using two-dimensional electrophoresis (2-DE) in conjunction with a silver stain and Western blotting approach, we attempt to locate selected known prognostic markers for breast cancer. With these results, we can exclude these proteins from the future search for potential pharmaceutical targets, using the same techniques. The proteins that were located include the estrogen receptor-alpha, beta-casein, cytokeratin 7, calponin and bax. For each protein an estimated M(r) and pI was gained. Each protein was found in multiple variants. By locating these proteins the number of unknown proteins found on the 2-DE gel has been reduced, helping the future search for novel markers that are shown as being differentially expressed between healthy and cancerous tissue samples.     

Identification of a novel population of human cord blood cells with hema-topoietic and chondrocytic potential

With the exception of mature erythrocytes, cells within the human hematopoietic system are characterized by the cell surface expression of the pan-leukocyte receptor CD45. Here, we identify a novel subset among mononuclear cord blood cells depleted of lineage commitment markers (Lin-) that are devoid of CD45 expression. Surprisingly, functional examination of Lin-CD45- ceils also lacking cell surface CD34 revealed they were capable of multipotential hematopoietic progenitor capacity. Co-culture with mouse embryonic limb bud cells demonstrated that Lin^-CD45^-CD34^- cells were capable of contributing to cartilage nodules and differentiating into human chondrocytes. BMP-4, a mesodermal factor known to promote chondrogenesis, significantly augmented Lin^-CD45^-CD34^-differentiation into chondrocytes. Moreover, unlike CD34~ human hematopoietic stem cells, Lin^-CD45^-CD34^- cells were unable to proliferate or survive in liquid cultures, whereas single Lin^-CD45^-CD34^- cells were able to chimerize the inner cell mass (1CM) of murine blastocysts and proliferate in this embryonic environment. Our study identifies a novel population of Lin-CD45-CD34^- cells capable of commitment into both hematopoietic and chondrocytic lineages, suggesting that human cord blood may provide a more ubiquitous source of tissue with broader developmental potential than previously appreciated.     

Microtubule-dependent oligomerization of tau. Implications for physiological tau function and tauopathies

The accumulation of abnormal tau filaments is a pathological hallmark of many neurodegenerative diseases. In 1998, genetic analyses revealed a direct linkage between structural and regulatory mutations in the tau gene and the neurodegenerative disease, frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17). Importantly, the FTDP-17 phenotype is transmitted in a dominant rather than a recessive manner. However, the underlying molecular mechanisms causing disease remain uncertain. The most common molecular mechanism generating dominant phenotypes is the loss of function of a multimeric complex containing both mutant and wild-type subunits. Therefore, we sought to determine whether tau might normally function as a multimer. We co-incubated 35S-radiolabeled tau and biotinylated tau with taxol stabilized microtubules, at very low molar ratios of tau to tubulin. Subsequent covalent cross-linking followed by affinity-precipitation of the biotinylated tau revealed the formation of microtubule-dependent tau oligomers. We next used atomic force microscopy to independently assess this conclusion. Our results are consistent with the hypothesis that tau forms oligomers upon binding to microtubules. In addition to providing insights into normal tau action, our findings lead us to propose that one mechanism by which mutations in tau may cause cell death is through the formation of tau complexes containing mutant tau molecules in association with wild-type tau. These wild-type-mutant tau complexes may possess altered biological and/or biophysical properties that promote onset of the FTDP-17 phenotype, including neuronal cell death by either altering normal tau-mediated regulation of microtubule-dependent cellular functions and/or promoting the formation of pathological tau aggregates.     

Comparative study of perturbations of peripheral markers in different stressors in rats

Stress has been implicated in the etiopathogenesis of several diseases. In the present study, the effects of acute (AS), chronic (CS), and chronic unpredictable stress (CUS) were studied on the ulcer index, adrenal gland mass, and biochemical and hormonal changes in rats. The stress was provided in the form of immobilization-immobilization for 150 min, once only, and for 10 consecutive days in CS and CUS. In CUS, animals received variable unpredictable stressors. Immediately after stress, animals were decapitated, blood was collected, and plasma was separated for the estimation of plasma glucose, triglyceride, cholesterol, creatine kinase (CK), corticosterone, and insulin. The adrenal gland and stomach were also dissected for mass and ulcer scoring, respectively. AS significantly increased the ulcer index, plasma glucose, CK, corticosterone, and insulin. CS and CUS significantly increased the ulcer index, adrenal gland mass, and corticosterone. In CS, a significant decrease in plasma triglyceride and cholesterol levels was found, but in CUS only cholesterol was decreased significantly. High CK activity and hyperglycemia maintain the energy demands of metabolism, and elevated corticosterone desensitizes the insulin receptor in AS. In CS and CUS, prolonged elevation of corticosterone shifts metabolism to utilization of lipids as a secondary substrate by gluconeogenesis. From our experiment, it is clear that AS causes maximum activation of energy metabolism, which becomes specific after habituation in prolonged CS. These biochemical manipulations in the body by using different types of stressors are good markers that can be of great use to understand, target, and manage stress-induced etiologies.     

Phytohormone-mediated transformation of sugars to starch in relation to the activities of amylases, sucrose-metabolising enzymes in sorghum grain

Indole-acetic acid (IAA) and abscisic acid (ABA) were fed throughcomplete liquid medium (containing 2, 4, 8% sucrose) to detached earheads of sorghum. The effect of these phytohormones on interconvertion ofsugarsand their transformation to starch in relation to the activities of-, -amylases, sucrose-synthase (synthesis), sucrose-phosphatesynthase and soluble invertases was studied in the grain. This effect on theuptake of (U-¹⁴C) sucrose by detached ear heads and incorporation of¹⁴C into free sugars and starch of grain and into free sugars ofinflorescence parts was also studied. At concentrations of up to 4%sucrose in the culture medium, IAA increased the content of total free sugarsinthe grain. However, accumulation of starch and activities of - and-amylases increased when lAA was present even beyond the 4%sucroseconcentration in the culture medium. At all sucrose concentrations, the effectsof ABA and IAA were opposite. With 4% sucrose, both phytohormones causedmaximum accumulation of starch in the grain. ABA enhanced the relativeproportion of sucrose in the sugar pool with a concomitant reduction in theactivities of soluble acid (pH 4.8) and neutral (pH 7.5) invertases. Incontrast, IAA decreased the sucrose proportion of grain sugars with asimultaneous elevation and reduction in the activities of invertases andsucrose-phosphate synthase, respectively. Irrespective of sucrose concentrationin the culture medium, the activity of sucrose synthase (synthesis) wasenhancedwith IAA as well as ABA at their 10 M concentration. IAA alsoenhanced incorporation of ¹⁴C from (U-¹⁴C) sucrose intothe EtOH extract (principally constituted by free sugars) and starch of thegrain, but ABA caused the reverse effect. Based on the results, it is suggestedthat IAA and ABA have contrasting effects on the transformation of sucrose tostarch in sorghum grain where its capacity to synthesise starch is modulatedpositively by IAA and negatively by ABA.     

Cryopreservation of goat oocytes and in vivo derived 2- to 4-cell embryos using the cryoloop (CLV) and solid-surface vitrification (SSV) methods

This study evaluated the efficiency and toxicity of two cryopreservation methods, solid-surface vitrification (SSV) and cryoloop vitrification (CLV), on in vitro matured oocytes and in vivo derived early stage goat embryos. In the SSV method, oocytes were vitrified in a solution of 35% ethylene glycol (EG), 5% polyvinyl-pyrrolidone (PVP), and 0.4% trehalose. Microdrops containing the oocytes were cryopreserved by dropping them on a cold metal surface that was partially immersed in liquid nitrogen. In the cryoloop method, oocytes were transferred onto a film of the CLV solution (20% DMSO, 20% EG, 10mg/ml Ficoll and 0.65 M sucrose) suspended in the cryoloop. The cryoloop was then plunged into the liquid nitrogen. In vivo derived embryos were vitrified using the same procedures. The SSV microdrops were warmed in a solution of 0.3M trehalose and those vitrified with CLV were warmed with incubation in 0.25 and 0.125 M sucrose. Oocytes and embryos vitrified by the SSV method had a significantly lower survival rate than the control (60 and 39% versus 100%, respectively; P<0.05), while the survival rate of CLV oocytes and embryos (89 and 88%, respectively) did not differ from controls. Cleavage and blastocyst rates of the surviving vitrified oocytes (parthenogenetically activated) and embryos (cultured for 9 days) were not significantly different (P>0.05) from the control nor did they differ between vitrification methods. Embryos vitrified with the CLV method gave rise to blastocysts (2/15). Our data demonstrated that the two vitrification methods employed resulted in acceptable levels of survival and cleavage of goat oocytes and embryos.