Production of interleukin 2 and interleukin 4 by immune CD4-CD8+ and their role in the generation of antigen-specific cytotoxic T cells

In this report we investigated the production and role of interleukin (IL)2 and IL4 in the generation of antigen-specific cytotoxic T cells (CTL). We used as our model the ultraviolet-light-induced epithelial tumor 1591, a highly immunogenic regressor tumor which evokes a strong cell-mediated immune response leading to rejection. We show that IL2 and IL4 are differentially required for the development of optimal cytolytic activity to the 1591 tumor in primary and secondary in vitro splenic cultures. First, anti-IL2 receptor monoclonal antibody (mAb) significantly decreased specific cytotoxicity in both primary and secondary splenic mixed lymphocyte-tumor cell culture (MLTC) cultures, but anti-IL4 mAb inhibited the cytotoxic responses only secondary and not primary cultures. Second, when supernatants from MLTC were tested for lymphokine activity, primary cultures produced only IL2 while secondary cultures produced both IL2 and IL4. Splenic cells were then depleted of CD4+ cells by negative selection, or enriched for CD8+ cells by positive selection, and tested for lymphokine production and requirements. CD8+ cells could not generate significant CTL activity in primary cultures, but could in secondary MLTC. The addition of mAb to either IL2 or IL4 significantly inhibited the generation of CTL by CD8+ cells in these secondary MLTC.CD8+ cells were also found to produce both IL2 and IL4 in secondary MLTC by functional and Northern blot analysis. The production of IL2 and IL4 by CD8+ cells occurs during different phases of culture, with IL2 being produced early (days 1 and 2) and IL4 late (days 3-5). In addition, the requirement of CD8+ cells for both IL2 and IL4 is unique for that lymphokine. These results suggest that both IL2 and IL4 are both produced and required by CD8+ cells during secondary MLTC, and suggest an additional cellular source of IL4 production besides CD4+ T cells during antigen-specific CTL responses.     

Phylogenetic and Pathotypic Characterization of Newcastle Disease Viruses Circulating in West Africa and Efficacy of a Current Vaccine

Newcastle disease (ND) is a deadly avian disease worldwide. In Africa, ND is enzootic and causes large economic losses, but little is known about the Newcastle disease virus (NDV) strains circulating in African countries. In this study, 27 NDV isolates collected from apparently healthy chickens in live-bird markets of the West African countries Benin and Togo in 2009 were characterized. All isolates had polybasic fusion (F)-protein cleavage sites and were shown to be highly virulent in standard pathogenicity assays. Infection of 2-week-old chickens with two of the isolates resulted in 100% mortality within 4 days. Phylogenetic analysis of the 27 isolates based on a partial F-protein gene sequence identified three clusters: one containing all the isolates from Togo and one from Benin (cluster 2), one containing most isolates from Benin (cluster 3), and an outlier isolate from Benin (cluster 1). All the three clusters are related to genotype VII strains of NDV. In addition, the cluster of viruses from Togo contained a recently identified 6-nucleotide insert between the hemagglutinin-neuraminidase (HN) and large polymerase (L) genes in a complete genome of an NDV isolate from this geographical region. Multiple strains that include this novel element suggest local emergence of a new genome length class. These results reveal genetic diversity within and among local NDV populations in Africa. Sequence analysis showed that the F and HN proteins of six West African isolates share 83.2 to 86.6% and 86.5 to 87.9% identities, respectively, with vaccine strain LaSota, indicative of considerable diversity. A vaccine efficacy study showed that the LaSota vaccine protected birds from morbidity and mortality but did not prevent shedding of West African challenge viruses.     

A Comparison of Continuous and Interrupted Suturing in Laparoscopic Pyeloplasty

Background:

Laparoscopic pyeloplasty is one of the most common reconstructive procedures performed by urologists. Both continuous and interrupted sutures are being practiced for ureteropelvic anastomosis. The success rate and the complications associated with the suturing technique needs evaluation. We analyzed the results from of our patients who underwent laparoscopic pyeloplasty using both techniques.

Objective:

To review the outcome differences among patients undergoing laparoscopic pyeloplasty regarding suturing technique.

Materials and Methods:

All patients who underwent laparoscopic, transperitoneal dismembered pyeloplasty of the primary pelviureteric obstruction were analyzed. The primary outcome was successful pyeloplasty, as assessed by the resolution of symptoms and T½ <10 minutes. The secondary outcomes were the complication rate and the operative parameters. The difference in the parameters was assessed by Student t test analysis.

Results:

Of the 107 patients we studied, 65 had interrupted suturing and 42 had continuous suturing. The success rate was not significantly different among the 2 groups. The mean suturing time, postoperative drainage volume, postoperative hospital stay, and total cost of the procedure were significantly less in the continuous suturing group.

Conclusion:

The continuous suturing technique is preferred over the interrupted suturing technique for laparoscopic pyeloplasty because the success rates are equal and the postoperative stay, suturing time, drain output, and cost of the procedure are better.     

Structure-activity relationship studies: M2 and CCR5 receptor antagonists

A wide range of neurotransmitters, polypeptides and inflammatory mediators transduce their signals into the interior of cell by specific interactions with cell-surface receptors that are coupled to G-protein. The most familiar G-protein-coupled receptors are muscarinic receptors, adrenergic receptors, dopaminergic receptors and opioid receptors. A single polypeptide chain of 400-500 residues forms most of these receptors. There are seven hydrophobic regions in the receptor and they correspond to transmembrane alpha-helices, which are membrane spanning domains. This topology is highly conserved among various members of the family of G-protein coupled receptors. The amino-terminal extracellular domain contains potential N-linked glycosylation sites in most receptors. The carboxyl-terminal is involved in the coupling to G-proteins and contains a cysteine site and phosphorylation site (Thr, Ser) and both are involved in receptor desensitization. In this section of the review we will discuss the development of potent, selective, low molecular weight antagonists of two G-protein coupled receptors (M(2) muscarinic receptor and CCR5 chemokine receptor) and their potential therapeutic utilities. The initial leads in both antagonist programs came from in house screening of our sample collections. As expected, most of the initial leads for both programs shared a similar pharmacophore and because of this showed strong affinity to many if not few a other G-protein coupled receptors. The initial significant challenge in both programs in terms of structure-activity studies was not only to optimize the structures for potency but also selectivity versus other subtype receptors. In the M(2) antagonist program the selectivity versus M(1) and other subtypes was a major challenge. Similarly in the CCR5 antagonist program the selectivity versus M(2) was a significant issue to overcome. In this review we will discuss in detail the structure activity relationships that resulted in potent and selective antagonists.     

Biochemical studies on the cardioprotective effect of glutamine on tissue antioxidant defense system in isoprenaline-induced myocardial infarction in rats

Oxidative stress is one of the mechanisms with a central role involved in the pathogenesis of myocardial infarction. The protective effect of glutamine on myocardial antioxidant defense system was investigated during isoprenaline-induced myocardial infarction, an animal model of myocardial infarction of human beings. Levels of diagnostic marker enzymes in plasma, reduced glutathione (GSH) and lipid peroxides and the activities of glutathione peroxidase, glutathione-S-transferase, catalase and superoxide dismutase in heart tissue were determined. Injection of isoprenaline caused significant increases in the levels of diagnostic marker enzymes in plasma and lipid peroxidation in heart tissue. A parallel decline in the levels of ATP (Adenosine triphosphate) and GSH and the activities of glutathione-dependent antioxidant enzymes and antiperoxidative enzymes in heart tissue was also observed. Prior oral administration of glutamine significantly prevented isoprenaline-induced adverse effects and maintained myocardial antioxidant status at near normal status. The cardioprotective effect of glutamine is probably related to a strengthening of the myocardial membrane by its membrane stabilizing action, or to a counteraction of free radicals by its antioxidant property, or to its ability to maintain near to normal status the activities of free radical scavenging enzymes and the level of GSH, which protect myocardial membrane against oxidative damage by decreasing lipid peroxidation.     

Mosquito larvicidal, ovicidal, and repellent properties of botanical extracts against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus (Diptera: Culicidae)

Mosquito-borne diseases have an economic impact, including loss in commercial and labor outputs, particularly in countries with tropical and subtropical climates; however, no part of the world is free from vector-borne diseases. In mosquito control programs, botanical origin may have the potential to be used successfully as eggs, larvae, and adult. The larvicidal, ovicidal, and repellent activities of crude benzene and ethyl acetate extracts of leaf of Ervatamia coronaria and Caesalpinia pulcherrima were assayed for their toxicity against three important vector mosquitoes, viz., Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus (Diptera: Culicidae). The larval mortality was observed after 24 h of exposure. All extracts showed moderate larvicidal effects; however, the highest larval mortality was found in benzene extract of E. coronaria against the larvae of Anopheles Stephensi, Aedes aegypti, and Culex quinquefasciatus with the LC₅₀ and LC₉₀ values were 79.08, 89.59, and 96.15 ppm and 150.47, 166.04, and 174.10 ppm, respectively. Mean percent hatchability of the ovicidal activity was observed 48 h posttreatment. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. The leaf extract of E. coronaria was found to be most effective than Caesalpinia pulcherrima against eggs/egg rafts of three vector mosquitoes. For E. coronaria, the benzene extract exerted 300, 250, and 200 ppm against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus, respectively. The results of the repellent activity of benzene and ethyl acetate extract of E. coronaria and Caesalpinia pulcherrima plants at three different concentrations of 1.0, 2.5, and 5.0 mg/cm² were applied on skin of fore arm in man and exposed against adult female mosquitoes. In this observation, these two plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the repellent activity is dependent on the strength of the plant extracts. These results suggest that the leaf solvent plant extracts have the potential to be used as an ideal ecofriendly approach for the control of mosquitoes. This is the first report on the mosquito larvicidal, ovicidal, and repellent activities of the reported E. coronaria and Caesalpinia pulcherrima plants.