Gonadotropin-releasing hormone stimulates thyroid activity in a freshwater murrel, Channa gachua (ham.), and Carps, Catla catla (ham.) and Cirrhinus mrigala (ham.)

Injections of mammalian GnRH (mGnRH), salmon GnRH (sGnRH), and a homologous murrel, Channa punctatus, GnRH (cGnRH) to a murrel, Channa gachua, and a carp, Catla catla, at a dose of 1 microg/250 g body wt significantly increased plasma thyroxine (T4) levels above control. Piscine GnRHs (sGnRH and cGnRH) had significantly greater stimulatory effects compared with mGnRH. To observe whether this stimulatory effect by GnRHs is direct or indirect, thyroid follicles were isolated from hypobranchial muscles of freshwater murrel, C. gachua and incubated (1 x 10(6) follicles/well) in vitro at 30 degrees C for 2 h without hormone and for 3 h with hormones. Addition of these three GnRHs separately at a concentration of 1 microg/well stimulated T4 secretion; sGnRH and cGnRH caused greater secretion of T4 into the medium compared with mGnRH. Specificity of GnRH action in vitro was assessed by using anti-GnRH antibody which significantly (P < 0.01) inhibited GnRH-augmented T4 secretion. To gain further insight, 125I uptake by thyroid follicles and formation of [125I]T4 from this radioiodine pool was monitored in the presence or absence of sGnRH. sGnRH greatly augmented 1251 uptake by the follicles which resulted a fourfold increase in [125I]T4 formation out of this pool of 125I compared with the control. The results indicate GnRH stimulation of thyroid hormone formation and release in these teleosts suggesting a possible different mode of regulation of thyroid hormone secretion in teleosts.

Immunology of cancer cervix

It is not clear how much genetic factor is responsible for causing cervical cancer, but certainly there has some mutation abnormality in the suppressive p53 gene which is to be proved beyond doubt. In addition to this, there are some environmental factors which make insults on cervical epithelium. Immunology of cancer cervix is well represented by (1) immunology of cancer, (2) immunology of virally controlled antigen and (3) cancer cervix antigen markers. The cancer is an example of transplantation immunology changes in the surface of tumour cells during replication. Human papillomavirus (HPV) DNA has been shown to be associated with high grade cervical intra-epithelial neoplasia (CIN). Squamous cell carcinoma antigen has been investigated for predictive value in cancer cervix. Colony stimulating factor-1 causes monocytic cells aggregation in neoplastic area and plays as initiators of the sequence of inflammation up to neoplasia.

Effect of nickel on testicular nucleic acid concentrations of rats on protein restriction

The nucleic acids (DNA and RNA) and total protein concentration in testes were estimated in male Wistar strain rats treated intraperitorally with nickel sulfate (2.0 mg/100 g body weight) on alternate days for 10 dosages. In both normal (18% casein) and protein-restricted (5% casein) experimental animals, the nucleic acids and total protein concentration were found to decrease significantly compared to the corresponding controls. Sperm count and sperm motility were also reduced in both experimental groups of animals. The results indicate that nickel influences the expression of genetic information by reducing testicular nucleic acids and protein concentration in both dietary experimental groups.

Molecular characterization and immunohistochemical localization of IV(4)GalNAcGgOse(4)Cer: a naturally occurring novel neutral glycosphingolipid in bovine brain

A pair of novel neutral glycosphingolipids (Ngsls) has been identified in bovine brain. Their mobilities on thin layer chromatography were slightly different from a standard pentaglycosylceramide (nLcOse(5)Cer from bovine erythrocytes). The compounds were purified to homogeneity by column chromatography. Their fatty acid and base compositions, their monosaccharide compositions and sugar linkage positions were determined by gas-liquid chromato-graphy/mass spectrometry. Carbohydrate sequence analy-sis by(1)H NMR spectroscopy and stepwise exoglyco-sidase digestion indicated the following pentaglycosyl structure for the oligosaccharide moiety of both Ngsls: GalNAcbeta1-4Galbeta1-3GalNAcbeta1-4Galbeta1-4Gl c. The two Ngsls (abbreviated as IV(4)GalNAcGgOse(4)Cer or GalNAc-GA1), differ in their ceramide compositions, having d18:0 and d18:1 sphingosine as their long chain bases. A monospecific polyclonal anti-GalNAc-GA1 antibody, prepared in rabbit and purified by affinity chromatography, stained the neurons of cerebral cortex and cerebellum including Purkinje cells in adult rat brain, indicating that the novel GalNAc-GA1 is associated with cerebellar and other neurons in vertebrate central nervous system.

The utility of waist circumference in assessment of obesity

The objective of this study was to assess the correlation between waist circumference and waist hip ratio and body mass index. Also to assess if a simple measurement like the waist circumference can be used as an independent indicator for detecting health risk and management. 500 men and 500 women were included in this study from the out patient department and indoor wards of Medical College, Calcutta. Only 7% of the males and 16% of the females had body mass index > or = 25. About 50% of both males and females had waist hip ratio above the desirable range (0.80 for females and 0.95 for males). About 99% of females with, waist circumference > or = 72 cm. had either body mass index > or = 25 or high waist hip ratio > or = 0.80 or both. Similarly 99% of males with waist circumference > or = 80 cm. had either high body mass index > or = 25 or high waist hip ratio > or = 0.90 or both. Waist circumference is simple to assess and can be used as an independent measurement to identify those at risk from either increased body weight or central fat distribution or both.

Mutual suppression of mukB and seqA phenotypes might arise from their opposing influences on the Escherichia coli nucleoid structure

A strain of Escherichia coli in which both the seqA and mukB genes were inactivated displayed partial suppressions of their individual phenotypes. Temperature sensitivity, anucleate cell production and poor nucleoid folding seen in the mukB strain were suppressed by the seqA null mutation, whereas filamentation, asymmetric septation and compact folding of the nucleoids observed in the seqA strain were suppressed by inactivation of the mukB gene function. However, the asynchronous initiation of chromosome replication in the seqA strain was not reversed in the mukBseqA double mutant. Membrane-associated nucleoids were isolated from the wild-type, mukB, seqA and mukBseqA strains and their sedimentation rates were compared under identical conditions. Whereas the mukB mutation caused unfolding of the nucleoid, the seqA mutation led to a more compact packaging of the chromosome. The mukBseqA double mutant regained the wild-type nucleoid organization as revealed from its rate of sedimentation. Microscopic appearances of the nucleoids were consistent with the sedimentation profiles. The mukB mutant was oversensitive to novobiocin and this susceptibility was suppressed in the mukBseqA strain, suggesting possible roles of MukB and SeqA in maintaining chromosome topology. The mutual phenotypic suppression of mukB and seqA alleles thus suggests that these genes have opposing influences on the organization of the bacterial nucleoid.

Immunosuppression in hamsters with progressive visceral leishmaniasis: an evaluation of the role of nitric oxide toward impairment of the lymphoproliferative response

The progressive visceral infection caused in golden hamsters by Leishmania donovani amastigotes led to gradual impairment of the proliferative response of their splenic (SPMC) or peripheral blood (PBMC) mononuclear cells to in vitro stimulation with leishmanial antigen, with mitogen (concanavalin A), and even with a combination of phorbol myristate acetate (PMA) and ionomycin (Io). Removal of macrophage-like adherent cells from SPMC or PBMC of infected animals, however, almost completely restored their proliferative response to PMA + Io, thus ruling out the possibility of any intrinsic defect in the signal-transduction pathways of lymphocyte activation and proliferation. Subsequent studies demonstrated that the generation of soluble mediators such as nitric oxide by these adherent cells is responsible, albeit partially, for the down-regulation of the lymphoproliferative response in hamsters with visceral leishmaniasis.

Gentamicin induced inhibition of steroidogenic enzymes in rat testis

Gentamicin is an aminoglycoside antibiotic, widely used for treating many gram negative bacterial infections. Though nephrotoxicity is the most highlighted side effect, it has also been found to cause an alteration in the phosphatase activities of testes and accessory sex organs and a decline in the sperm count. This study was designed to assess the effects of gentamicin on testicular steroidogenesis and to ascertain whether such alterations are reversible. Laboratory inbred adult, male, 'Wistar' strain rats were chosen as the experimental animal. A significant dose-dependant reduction in the activities of the two steroidogenic enzymes, accompanied with a significant decrease in ascorbic acid and elevation of level of cholesterol was observed. The effects were maximum at a dose of 100 mg/kg, b.wt. After 15 days of withdrawal of the drug therapy the biochemical parameters namely ascorbic acid and cholesterol returned to normal levels whereas the activities of the two dehydrogenases showed a compensatory increase. This indicates that gentamicin affects the steroidogenic enzymes, causing an alteration in the formation of testosterone, which was manifested in the elevated cholesterol in the adult rat testes. However, these alterations were reversible.

Therapeutic and prophylactic uses of protein A in the control of Leishmania donovani infection in experimental animals

The role of the immunomodulator Protein A (PA) (from Staphylococcus aureus, Cowan I strain) in the control of leishmanial infection was studied in experimental animals. Treatment of Leishmania donovani infected hamsters with PA led to a moderate level of reduction of parasite load in their spleen (68%) and liver (46%). However, combination therapy of PA with the antileishmanial drug stibanate induced a more marked reduction of the spleen (88%) and liver (85%) parasitemia compared to that induced by PA or drug treatment alone. Similar results were also obtained with L. donovani infected BALB/c mice as the combination therapy of PA and stibanate led to a significant reduction (84%) of liver parasite load in comparison to that induced by PA (38%) or drug (61%) treatment alone. Apart from its therapeutic use, PA could also be used as a prophylactic agent in the control of leishmanial infection. Thus, treatment of hamsters with PA before leishmanial challenge significantly reduced their organ parasite load (by 59-78%) compared to that observed in infected controls without prior PA treatment. The antileishmanial effect of PA was likely to be mediated through the activation of macrophages leading to an enhancement of their phagocytic as well as leishmaniacidal activities. Subsequent studies demonstrated that PA treatment led to an increased production of nitric oxide by macrophages which could primarily be responsible for their enhanced parasite killing ability.

Pulse polio immunisation, 1995-96: an evaluation in West Bengal

An evaluation of the Pulse Polio Immunisation Programme (PPI), 1995-96 in West Bengal was undertaken. It was observed that the PPI coverage (with two rounds) was 84.1%. Variations in the PPI coverage level were documented in relation to age, sex, residential status and parental literacy status of the beneficiaries. However, significantly lower PPI coverage was observed among Muslims (p < 0.001) and Scheduled Tribes (p < 0.01). The principal agency responsible for disseminating information about PPI was identified to be the multipurpose health workers. Some of the major reasons for non-acceptance of PPI were lack of information, illness of the child, absence of the child on the "PPI day", lack of faith in immunisation and fear of adverse reaction.

Conversion to bidirectional replication after unidirectional initiation from R1 plasmid origin integrated at oriC in Escherichia coli

The cell division phenotypes of Escherichia coli with its chromosome replication driven by oriR (from plasmid R1) were examined by fluorescence microscopy and flow cytometry. Chromosome replication patterns in these strains were followed by marker frequency analyses. In one of the strains, the unidirectional oriR was integrated so that the replication fork moved clockwise from the oriC region, and bacterial growth and division were similar to those of the wild-type parent. The bacteria were able to convert the unidirectional initiation from oriR into bidirectional replication. The site for conversion of uni- to bidirectional replication seemed to be localized and could be mapped genetically within 6 min to the immediate right of the minimal oriC. Replication starting in the counterclockwise direction from the R1 replicon integrated at the same site in the opposite orientation could not be described as either bi- or unidirectional, as no single predominant origin could be discerned from the more or less flat marker frequency pattern. These strains also showed extensive filamentation, irregular nucleoid distribution and the presence of anucleate cells, indicative of segregation and division defects. Comparison among intR1 derivatives differing in the position of the integrated oriR relative to the chromosome origin suggested that the oriC sequence itself was dispensable for the conversion to bidirectionality. However, passage of the replication fork over the 6 min region to the right of oriC seemed important for the bidirectional replication pattern and normal cell division phenotype.

Co-ordinated expression of multiple enzymes in different subcellular compartments in plants

A gene expression system designed for coordinated expression of multiple genes in plants and their targeting to specified subcellular locations was tested. A series of genes encoding polyproteins containing the tobacco vein mottling virus (TVMV) Nla proteinase along with two other reporter genes (those encoding the Escherichia coli acetate kinase (ACK) and Tn9 chloramphenicol, acetyl transferase (CAT) enzymes) were assembled. The respective coding sequences of these genes were separated by a TVMV Nla proteinase recognition sequence. In addition, in some instances, chloroplast targeting information (a transit peptide (TP) from a pea rbcS gene) was incorporated into the polyprotein. We found that the Nla proteinase can be used to express, as individual polypeptides, the ACK and CAT proteins, and that these proteins retain enzymatic activity. Polyproteins with the structure TP-Nla-ACK-CAT or TP-ACK-CAT-Nla failed to yield chloroplast-localized ACK and CAT proteins, although the latter did give rise to a chloroplast-localized ACK-CAT polyprotein. These results indicate that the Nla proteinase acts in cis more rapidly than transport of proteins into the chloroplast, but that chloroplast localization can take place before complete processing of the polyprotein. Polyproteins with the structures ACK-Nla-TP-CAT and TP-ACK-Nla-TP-CAT yielded appropriately processed and targeted ACK and CAT. Our results show that subcellular localization signals can be effectively recognized in the context of a polyprotein, and they suggest an appropriate strategy for simultaneous engineering of multiple subcellular compartments in plants.

Sentinel surveillance on poliomyelitis and neonatal tetanus: a report

A 5 year sentinel surveillance (1989-93) of paralytic poliomyelitis and neonatal tetanus was undertaken at a rural Medical College Hospital at Burdwan, West Bengal. Poliomyelitis incidence showed an overall declining trend, which corroborated with the increased OPV coverage over the years. Incidence was more in males than females. Male:female ratio varied between 2.31:1 to 1.2:1. From 1989 to 1992, age-shift in poliomyelitis was observed when more cases were occurring above 1 year subjects. Cases were reported to be high during the months June to September every year. Incidence of neonatal tetanus (NNT) also showed a declining trend during the 5 year study period. A male preponderance was observed. NNT cases were more prevalent during the months between August and November. In an attempt for eradication of paralytic poliomyelitis and elimination of NNT, containment and other public health measures were undertaken a part of surveillance activities. The obstacles encountered in the surveillance system, as well as lacunae identified in undertaking appropriate health measures was discussed.

Genetic uncoupling of the dsRNA-binding and RNA cleavage activities of the Escherichia coli endoribonuclease RNase III--the effect of dsRNA binding on gene expression

RNase III, a double-stranded RNA-specific endonuclease, is proposed to be one of Escherichia coli's global regulators because of its ability to affect the expression of a large number of unrelated genes by influencing post-transcriptional control of mRNA stability or mRNA translational efficiency. Here, we describe the phenotypes of bacteria carrying point mutations in rnc, the gene encoding RNase III. The substrate recognition and RNA-processing properties of mutant proteins were analysed in vivo by measuring expression from known RNase III-modulated genes and in vitro from the proteins' binding and cleavage activities on known double-stranded RNA substrates. Our results show that although the point mutation rnc70 exhibited all the usual rnc null-like phenotypes, unlike other mutations, it was dominant over the wild-type allele. Multicopy expression of rnc70 could suppress a lethal phenotype of the wild-type rnc allele in a certain genetic background; it could also inhibit the RNase III-mediated activation of lambdaN gene translation by competing for the RNA-binding site of the wild-type endonuclease. The mutant protein failed to cleave the standard RNase III substrates in vitro but exhibited an affinity for double-stranded RNA when passed through poly(rI):poly(rC) columns. Filter binding and gel-shift assays with purified Rnc70 showed that the mutant protein binds to known RNase III mRNA substrates in a site-specific manner. In vitro processing reactions with purified enzyme and labelled RNA showed that the in vivo dominant effect of the mutant enzyme over the wild-type was not necessarily caused by formation of mixed dimers. Thus, the rnc70 mutation generates a mutant RNase III with impaired endonucleolytic activity but without blocking its ability to recognize and bind double-stranded RNA substrates.

Experience in running a Diarrhoeal Training cum Treatment Unit (DTTU) in a state teaching hospital in Calcutta

The performance of the Diarrhoeal Training cum Treatment Unit (DTTU) of NRS Medical College and Hospital, Calcutta, in a 2-year period was evaluated by record analysis. The study revealed that 73.6% cases out of a total 4349 could be successfully managed at the oral rehydration therapy (ORT) area and only 16.5% cases required indoor admission. Rest of the cases (9.9%) with "no dehydration" were sent home with advice. There were 84.7% cases out 3919 dehydration cases who could be successfully treated by ORT and only 15.3% required intravenous (i.v.) therapy. A definite decline was also evident in the proportion of diarrhoea cases requiring antibiotic therapy (13.5% in 1991 to 6.8% in 1992). The case fatality rate due to diarrhoea was 1.7% in 1992. Had all cases of diarrhoea with dehydration being admitted and treated with i.v. fluids and antibiotics, the estimated cost would have been Rs 14.2 lakhs, which with ORT, actually cost Rs 2.4 lakhs. Thus estimated total cost reduction was to the extent of Rs 11.8 lakhs in a 2-year period.

Cell cycle arrest in Era GTPase mutants: a potential growth rate-regulated checkpoint in Escherichia coli

Era is a low-molecular-weight GTPase essential for Escherichia coli viability. The gene encoding Era is found in the rnc operon, and the synthesis of both RNase III and Era increases with growth rate. Mutants that are partially defective in Era GTPase activity or that are reduced in the synthesis of wild-type Era become arrested in the cell cycle at the predivisional two-cell stage. The partially defective Era GTPase mutation (era1) suppresses several temperature-sensitive lethal alleles that affect chromosome replication and chromosome partitioning but not cell division. Our results suggest that Era plays an important role in cell cycle progression at a specific point in the cycle, after chromosome partitioning but before cytokinesis. Possible functions for Era in cell cycle progression and the initiation of cell division are discussed.

Physiological, biochemical and histological changes due to physostigmine in monkeys

Physostigmine (Phy), a short-acting reversible anticholinesterase agent is considered to be a potent prophylactic antidote for the highly toxic organophosphorous (OP) compounds. The toxic effects, if any, of the probable prophylactic doses of Phy have been evaluated by studying its physiological, biochemical and histological effects in monkeys. Phy only at 100 micrograms/kg resulted in certain cholinergic signs such as salivation, lacrymation and muscular faciculations; physiological changes such as mild tachycardia, tachypnea, higher amplitude in electrical activity of the brain, clinico-chemical effects like fall in PO2, PCO2 and alkalosis and histologically an inflammatory reaction in the lungs. On the other hand, the lower dose, i.e. 50 micrograms/kg appeared to be devoid of cholinergic signs and symptoms. However, we observed a significant inhibition of both plasma and erythrocyte ChE and increase in the rectal temperature in both the Phy treated groups. From this study, Phy at a dose of 50 micrograms/kg could be inferred as a safe, sign free intramuscular dose and may probably be used in pretreatment regimen against nerve agents.

Alteration of testicular biochemistry during protein restriction in nickel treated rats

Nickel sulfate (2.0 mg/100 g.b.wt) dissolved in double-distilled water was administered (i.p.) on alternate days for ten doses to normal protein-fed and protein-restricted Wister strain albino rats (b.wt. 160 +/- 5 g). Two groups were used: one with normal protein diet, whereas the other with protein-restricted diet served as control. Twenty-four hours after the last treatment, the animals were sacrificed by decapitation. Tissues such as the testes, seminal vesicles, epididymis (Cauda and Caput) and prostate were dissected out, wiped clean, and stored at -20 degrees C until analysis. Lactate dehydrogenase (LDH) activities, glutamate oxaloacetate transaminase (GOT) activities, glycogen content, cholesterol content, and total protein content of the testes were estimated. Nickel sulfate administration significantly decreased the body weight of both normal protein-fed and protein-restricted groups of animals; the organ weights were also decreased. Significant decrease of LDH activity was observed, but GOT activity was not altered significantly. Testicular glycogen and cholesterol increased significantly in both experimental groups, but total protein content decreased. Nickel sulfate seems to have an adverse effect on the male reproductive system in both groups of animals fed with normal protein (18% casein) diet and protein restricted (5% casein) diet.

Influence of ascorbic acid on acid and alkaline phosphatase activities in some metabolically active tissues of aspirin treated rats

ACP and ALP activities in plasma were increased in aspirin treated groups for a period of seven days. Ascorbic acid supplemented groups showed no significant change in plasma ACP activity, but a significant change in ALP activity was found. ACP and ALP activities in liver and kidney were decreased significantly in aspirin treated animals. ACP activities in liver and kidney in ascorbic acid supplemented groups showed no significant changes. No significant alteration of ALP activity in liver was found in ascorbic acid supplemented group but a significant changes was observed in kidney. Supplementation of ascorbic acid in high doses to rats fed aspirin can restore enzyme activities almost to the normal level.