The concentration of pesticides in sediments from Kolleru Lake in India

Kolleru Lake is the largest natural freshwater lake in India. Sediment samples were collected at different locations from Kolleru Lake at different seasons in a year over a period of three years and analyzed for eight selected pesticides. In general, pesticides were present at all locations. The selected pesticides alpha-BHC, gamma-BHC, malathion, chlorpyrifos and endosulfan were present at higher concentrations than isodrin, dieldrin and p,p'-DDT. The concentrations of alpha-BHC, gamma-BHC malathion, chlorpyrifos, isodrin, endosulfan, dieldrin and p,p'-DDT in sediments were 1.2-388, 1.4-212, from below the minimum detection limit (BDL)-186, 1.1-292, BDL-38.6, BDL-206, BDL-128 and BDL-191 micrograms kg-1 dry weight, respectively. The aim of this study is to evaluate baseline data, to try to account for the concentration of pesticides in sediments and to discuss their potential to affect human beings and aquatic organisms.

Genetic Resistance of Pearl Millet Male-Sterile Lines to Diverse Indian Pathotypes of Sclerospora graminicola

Single-cross F₁ hybrid cultivars based on cytoplasmic-nuclear male-sterility (CMS) system have contributed significantly to increasing productivity of pearl millet (Pennisetum glaucum). Genetic resistance to downy mildew (Sclerospora graminicola) in parental lines is critical for successful commercial cultivation of a hybrid cultivar. In this study, 46 genetically diverse male-sterile lines (A-lines), including 42 test A-lines, four control A-lines, a commercial hybrid, and a highly susceptible line, were evaluated in disease nurseries at four diverse locations in India and compared with pathotype isolates from the same locations under greenhouse environments. Variability in downy mildew incidence (0 to 100%) due to genetic differences among lines, among pathotypes, and that due to line × pathotype interaction were all highly significant (P < 0.001). In the field experiment, eight of the 42 test A-lines, including 841A (control), that recorded ≤10% disease incidence, were identified as resistant compared with 84 to 100% incidence on the control susceptible line 7042S. Resistance in eight of these test A-lines (863A, ICMA 88004, -94333, -98222, -98111, -92777, and -96666) and 841A was confirmed against the four pathotypes in greenhouse experiments. Cluster analysis of downy mildew incidence data from field and greenhouse experiments, using the Euclidian distance, classified the 48 lines into four distinct groups with the above eight A-lines in the resistant group. These resistant A-lines would be useful in the development of F₁ hybrids with stable resistance to diverse pathotypes of downy mildew in India.

Novel method for isolation of major phenolic constituents from cashew (Anacardium occidentale L.) nut shell liquid

Commercially available cashew (Anacardium occidentale L.) nut shell liquid (CNSL) mainly contains the phenolic constituents anacardic acid, cardol, and cardanol. These phenolic constituents are themselves heterogeneous, and each of them contains saturated, monoene, diene, and trienes in the fifteen-carbon side chain. This communication describes the separation of anacardic acid, cardol, and cardanol for industrial application. Anacardic acid was selectively isolated as calcium anacardate. The acid-free CNSL was treated with liquor ammonia and extracted with hexane/ethyl acetate (98:2) to separate the mono phenolic component, cardanol. Subsequently, ammonia solution was extracted with ethyl acetate/hexane (80:20) to obtain cardol.

Quality of drinking water from ponds in villages of Kolleru Lake region

Kolleru Lake is the largest natural freshwater lake in the districts of East and West Godavari of Andhra Pradesh. The major population centres in the Kolleru Lake region are the 148 villages of which 50 bed villages and 98 belt villages. All bed and belt villages in lake region have at least one drinking water pond. Drinking water ponds are filled with lake water during monsoon season and directly supplied to the public throughout the year. The water samples were collected from village drinking water ponds in a year by covering three seasons and analysed for different physico-chemical parameters to assess the quality of drinking water.

Ex vivo generation of effective Epstein-Barr virus (EBV)-specific CD8+ cytotoxic T lymphocytes from the peripheral blood of immunocompetent Epstein Barr virus-seronegative individuals

BACKGROUND

Although readily accomplished from immunocompetent Epstein-Barr virus- (EBV) seropositive individuals, the effective ex vivo generation of EBV-specific cytotoxic T lymphocytes (CTL) from the peripheral blood mononuclear cells (PBMC) of EBV-seronegative subjects has proven to be a challenge. The focus of our study was to ascertain optimized culture conditions required for the ex vivo generation of EBV-reactive autologous CTL from the PBMC of EBV-seronegative volunteers.

METHOD

Freshly isolated PBMC obtained from immunocompetent EBV-seronegative and -seropositive individuals were used to generate EBV-specific autologous CTL lines using both conventional and a novel, modified ex vivo culture technique.

RESULTS

In contrast to responses observed in EBV-seropositives after two to three rounds of ex vivo stimulation, gamma-irradiated autologous lymphoblastoid cell lines (LCL) were incapable of eliciting an effective anti-EBV cytotoxic response when freshly-isolated PBMC from EBV-seronegative individuals were used as responders. Under these culture conditions, CD4+ T cells with preferential expression of the Th2-type cytokine IL-4 were predominantly expanded in the PBMC obtained from EBV-seronegative individuals. However, the addition of recombinant human (rh) IL-12 during the primary phase of ex vivo stimulation resulted in augmentation of EBV-specific cytolysis of autologous LCL by CD8+ T cells. Furthermore, there was down-regulation in the secretion of IL-4 and up-regulation in that of the Th1-type cytokine IFN-gamma by responder CD4+ and CD8+ T cells.

CONCLUSIONS

Taken together these data suggest that the addition of rhIL-12 during the primary phase of ex vivo stimulation of freshly isolated PBMC from EBV-seronegative individuals results in skewing of the immune response predominantly towards a CD4+ Th1-type (IFN-gamma) with the generation of an efficacious CTL-mediated anti-EBV reactivity. This novel ex vivo approach for generating effective autologous EBV-specific CTL could be adopted to treat refractory post-transplant lymphoproliferative disorders, which may be encountered in EBV-seropositive-->EBV-seronegative organ transplant recipients. Additionally, these ex vivo generated anti-EBV T cells could also be infused perioperatively to enhance prophylactically immunity against EBV infection in high-risk EBV-seronegative organ allograft recipients.

Isolation of the regulatory regions and genomic organization of the porcine alpha1,3-galactosyltransferase gene

BACKGROUND

Alpha1,3-galactosyltransferase (alpha1,3GT) is an enzyme that produces carbohydrate chains termed alphaGal epitopes found in most mammals, although some species of higher primates, including human, are notable exceptions. The evolutionary origin of the lost alpha1,3GT enzyme activity is not yet known, although it has been suggested that the promoter activity of this gene in the ancestors of higher primates was inactivated.

METHODS

We used 5'-or 3'-RACE, GenomeWalking, reverse transcriptase polymerase chain reaction (RT-PCR) and dual Luciferase reporter assay for identification of the full-length cDNA, which includes the transcription initiation site and the promoter region of porcine alpha1,3GT gene.

RESULTS

The region around exon 1 is guanine and cytosine (GC)-rich (about 70%), comprising a CpG island spanning more than 1.5 kbp. The 5'-flanking region of exon 1 contains multiple transcription factor consensus motifs, including GC-box, SP1, AP2, and GATA-box sites, in the absence of TATA or CAAT-box sequences. The entire gene consists of three 5' noncoding and six coding region exons spanning more than 52 kbp. Detailed analysis of alpha1,3GT transcripts revealed two major alternative splicing patterns in the 5'-untranslated region (5'-UTR) and evidence for minor splicing activity that occurs in a tissue-specific manner. Interspecies comparison of 5'-UTR shows minimal homology between porcine and murine sequences except for exon 2, which suggests that the regulatory regions differ among species.

CONCLUSIONS

These observations have important implications for experiments involving genetic manipulation of the alpha1,3GT gene in transgenic animals in terms of promoter utilization, and particularly in genetically engineering cells for the animal cloning technology by nuclear transfer.

Enhanced synthesis and reduced metabolism of endothelin-1 (ET-1) by hepatocytes--an important mechanism of increased endogenous levels of ET-1 in liver cirrhosis

BACKGROUND/AIMS

Hepatic concentration of endothelin-1 (ET-1) is increased in human and experimental liver cirrhosis. Because of its potent actions in the liver, ET-1 has been suggested to play an important role in the pathophysiology of cirrhosis. Since hepatocytes are the major cell type to metabolize ET-1, we investigated whether their reduced capacity to degrade ET-1 is a mechanism of its elevated levels in cirrhosis.

METHODS

The expression of ET-1 receptors, ET-1 and endothelin converting enzyme (ECE), and metabolism of ET-1 and ECE activity were compared in hepatocytes isolated from control and carbon tetrachloride-induced cirrhotic rats.

RESULTS

ET-1 receptor density and receptor-mediated internalization of ET-1 were significantly increased in cirrhotic hepatocytes relative to the control cells. However, compared to control hepatocytes, metabolism of ET-1 by the cirrhotic cells was reduced significantly. Interestingly, hepatocytes were found to contain preproET-1 mRNA, ECE-1 mRNA and ET-1. PreproET-1 mRNA and ET-1 levels were increased in cirrhotic hepatocytes but their ECE mRNA and ECE activity were not altered.

CONCLUSIONS

These results provide the first evidence that hepatocytes have the ability to synthesize ET-1 and demonstrate that decreased metabolism and enhanced synthesis, of ET-1 in hepatocytes are an important mechanism of its elevated levels in cirrhosis.

Endothelin stimulates transforming growth factor-beta1 and collagen synthesis in stellate cells from control but not cirrhotic rat liver

Interactions between hepatic stellate cells and endothelin-1 are implicated in liver fibrosis. We determined endothelin-1, its receptors and its effects on the synthesis of a fibrogenic agent transforming growth factor (TGF)-beta1 and collagen in stellate cells from control and CCl(4)-induced cirrhotic rats. The basal synthesis of endothelin-1, TGF-beta1 and collagen was much higher in cirrhotic stellate cells than in control cells. Endothelin-1 stimulated TGF-beta1 and collagen synthesis via endothelin ET(A) and endothelin ET(B) receptors, respectively, in control stellate cells, but did not elicit these effects in the cirrhotic cells despite increased density of the respective receptor subtypes in them. These results indicate that the actions of endothelin-1 on stellate cells may be an important physiological mechanism in maintenance of hepatic architecture. However, inability of endothelin-1 to stimulate TGF-beta1 and collagen synthesis in cirrhotic stellate cells suggests that it does not influence fibrogenic activity by direct action on them probably because the processes are already maximally activated.

Prokaryotic regulation of epithelial responses by inhibition of IkappaB-alpha ubiquitination

Epithelia of the vertebrate intestinal tract characteristically maintain an inflammatory hyporesponsiveness toward the lumenal prokaryotic microflora. We report the identification of enteric organisms (nonvirulent Salmonella strains) whose direct interaction with model human epithelia attenuate synthesis of inflammatory effector molecules elicited by diverse proinflammatory stimuli. This immunosuppressive effect involves inhibition of the inhibitor kappaB/nuclear factor kappaB (IkappaB/NF-kappaB) pathway by blockade of IkappaB-alpha degradation, which prevents subsequent nuclear translocation of active NF-kappaB dimer. Although phosphorylation of IkappaB-alpha occurs, subsequent polyubiquitination necessary for regulated IkappaB-alpha degradation is completely abrogated. These data suggest that prokaryotic determinants could be responsible for the unique tolerance of the gastrointestinal mucosa to proinflammatory stimuli.

The synthesis and evaluation of 2-substituted-7-(alkylidene)cephalosporin sulfones as beta-lactamase inhibitors

A series of 2-substituted-7-(alkylidene)cephalosporin sulfones were prepared and evaluated as beta-lactamase inhibitors. Compound 11c showed excellent activity as an inhibitor of the class C beta-lactamase derived from Enterobacter cloacae, strain P99.

A clinical trial combining donor bone marrow infusion and heart transplantation: intermediate-term results

BACKGROUND

Donor chimerism (the presence of donor cells of bone marrow origin) is present for years after transplantation in recipients of solid organs. In lung recipients, chimerism is associated with a lower incidence of chronic rejection. To augment donor chimerism with the aim to enhance graft acceptance and to reduce immunosuppression, we initiated a trial combining infusion of donor bone marrow with heart transplantation. Reported herein are the intermediate-term results of this ongoing trial.

METHODS

Between September 1993 and August 1998, 28 patients received concurrent heart transplantation and infusion of donor bone marrow at 3.0 x 10(8) cells/kg (study group). Twenty-four contemporaneous heart recipients who did not receive bone marrow served as controls. All patients received an immunosuppressive regimen consisting of tacrolimus and steroids.

RESULTS

Patient survival was similar between the study and control groups (86% and 87% at 3 years, respectively). However, the proportion of patients free from grade 3A rejection was higher in the study group (64% at 6 months) than in the control group (40%; P =.03). The prevalence of coronary artery disease was similar between the two groups (freedom from disease at 3 years was 78% in study patients and 69% in controls). Similar proportions of study (18%) and control (15%) patients exhibited in vitro evidence of donor-specific hyporesponsiveness.

CONCLUSIONS

The infusion of donor bone marrow reduces the rate of acute rejection in heart recipients. Donor bone marrow may play an important role in strategies aiming to enhance the graft acceptance.