Electron microscopic study of phages and aberrant structures produced by induction of prophage kappa in Vibrio cholerae el tor cells

Prophage kappa in V. cholerae el tor strain SLH22(J) could be induced spontaneously or by treatment with nitrofurantoin, though the efficiency of induction was very low (not more than 0.8%). V. cholerae el tor cells were found to release many different aberrant structures of the temperate phage, kappa. These aberrant structures were characterized by density gradient centrifugation and electron microscopy.

Synthetic RGD peptides derived from the adhesive domains of snake-venom proteins: evaluation as inhibitors of platelet aggregation

Synthetic peptides based on the RGD domains of the potent platelet aggregation inhibitors kistrin and dendroaspin were generated. The 13-amino-acid peptides were synthesized as dicysteinyl linear and disulphide cyclic forms. In platelet-aggregation studies, the cyclic peptides showed 3-fold better inhibition than their linear equivalents and approx. 100-fold greater potency than synthetic linear RGDS peptides derived from fibronectin. An amino acid substitution, Asp10-->Ala, in the kistrin-based peptide gave a 4-fold decrease in potency in the linear peptide, but produced a 2-fold elevation in the inhibitory activity of the cyclic form, generating a peptide of potency comparable with that of the parent protein.

Identification of multiple glucocorticoid receptor binding sites in the rat osteocalcin gene promoter

The biosynthesis of osteocalcin (OC), a bone-specific, noncollagenous protein, is stringently regulated during differentiation of the osteoblast phenotype. Glucocorticoids, and also 1,25(OH)2D3, mediate the developmental regulation of OC gene transcription. In this study, we established that the -1097 to +23 promoter (pOCZCat) of the rat OC gene confers glucocorticoid responsiveness to both basal and vitamin D-induced OC expression. The presence of multiple glucocorticoid receptor (GR) binding sites in the proximal rat OC gene promoter was determined by the combined use of DNase I footprinting, dimethyl sulfate fingerprinting, and gel mobility shift analysis with glucocorticoid receptor protein. One glucocorticoid receptor binding element (GRE) resides immediately downstream of the TATA box (-16 to -1). In vivo activity was established by cotransfection of ROS 17/2.8 osteosarcoma cells with an OC-CAT construct in the presence of cloned GRE sequences (wild type or mutant) as competitors. A putative second, less protected GR binding site is located further upstream in the OC gene basal promoter within the region overlapping the TATA box. This is in direct contrast to the organization of GREs in the human OC proximal promoter wherein GR binding at the upstream GRE overlapping the TATA is stronger than at the downstream GRE. In addition, we detected sequence-specific binding of GR protein to another basal promoter element, the OC box (-99 to -76), which contains a central CCAAT motif. The presence of multiple GR binding sites in the rat OC gene proximal promoter indicates that regulation of basal and vitamin D-enhanced transcription by glucocorticoids may involve the integrated activities of multiple, independent GREs.

Multiple mechanisms of serotonin 5-HT2 receptor desensitization

Desensitization of serotonin 5-HT2 receptor-mediated enhancement of the N-methyl-D-aspartate (NMDA) depolarization was studied in rat cortical neurons. Serotonin and (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) induced long term desensitization. Staurosporine, a nonspecific protein kinase C inhibitor, potentiated the serotonin and DOI facilitation, suggesting acute desensitization was operative. In the case of DOI, long term desensitization was prevented by staurosporine. Activators of protein kinase C abolished the serotonin facilitation, an action prevented by staurosporine. Concanavalin A potentiated the facilitation at 100 microM, but not 30 microM serotonin, suggesting these receptors undergo dose dependent internalization. Calmodulin antagonists prevent long term desensitization induced by serotonin. The depolarization induced by NMDA alone was not altered by staurosporine, protein kinase C activators, concanavalin A or calmodulin antagonists. Serotonin at 100 microM, but not 30 microM, induced heterologous desensitization of phenylephrine and carbachol induced facilitation of the NMDA depolarization. We conclude that serotonin 5-HT2 receptors both induce and undergo several forms of desensitization.

A five-year clinical evaluation of Norplant contraceptive subdermal implants in Bangladeshi acceptors

A non-comparative study of the Norplant contraceptive subdermal implant system was conducted in Dhaka, Bangladesh. The study was designed to evaluate the contraceptive efficacy, safety and overall acceptability of Norplant implants. Six hundred women were enrolled in the clinical trial, which began in 1985 at three study sites. Follow-up visits were scheduled at 1, 3, and 6 months after Norplant implant insertion, and every six months thereafter until removal or at the end of five years. There were no post-insertion pregnancies during Norplant implant use in this study. After five years of Norplant implant use, there was no clinically significant change in body weight, systolic or diastolic blood pressure. Less than 3% of the women ever reported having any significant medical problems such as migraine, respiratory or cardiac problems during the study. The gross cumulative continuation rate was 41.2 per 100 women at the end of five years. The two most frequently reported reasons for discontinuation during the study were menstrual problems and desired pregnancy. Of the women who completed the five-year user satisfaction questionnaire, the majority of the women (86.3%) planned to continue using contraception after study completion. Of these women, approximately one-third said they planned to use another Norplant set. The findings presented suggest that the Norplant system is a highly effective, safe and acceptable method among Bangladeshi women.

Characterisation of the wheat Mr 15000 "grain-softness protein" and analysis of the relationship between its accumulation in the whole seed and grain softness

The Mr 15000 protein associated with water-washed wheat starch granules from soft wheats was shown to be heterogeneous: it could be divided into a fraction containing one or moreα-amylase inhibitor subunits and a fraction largely composed of a previously uncharacterised polypeptide(s) referred to as the "grainsoftness protein" (GSP). The major N-terminal sequence and sequences of peptides derived from protease digests of GSP are reported. An antiserum specific for GSP was used to show that GSP accumulated in both hard and soft wheat grains, but the GSP in soft grains associated more strongly with starch granules than the GSP in hard grains. A positive correlation between grain softness and accumulation of GSP in the seed was demonstrated for a range of cultivars. This differs from the qualitative relationship, based on the isolated starch fraction, between GSP and grain softness that has already been reported. Analysis of wholemeal extracts with the antiserum demonstrated that the accumulation of GSP in the seed was dependent on the short arm of chromosome 5D, which also encodes theHa locus. In addition, examination of near-isogenic lines differing in hardness indicated that the gene(s) controlling GSP was (were) linked with theHa locus. The findings indicate that GSP may be the product of theHa locus and thus be the major factor that determines the milling characteristics of bread wheats.

Use of oral typhoid vaccine strain Ty21a in a New York state travel immunization facility

One hundred fifty-seven travelers who received the new oral typhoid vaccine strain Ty21a between April 1990 and February 1992 were surveyed by questionnaire to assess compliance and toxicity. The four-dose vaccine should be taken every other day before meals, and kept refrigerated between doses. Noncompliance with one or more of these instructions was seen in approximately 30% of travelers. Thirty-four (21.6%) took one or more doses after meals, 13 (8.3%) did not take all four doses, 10 (6.4%) failed to take the dose every other day, and five (3.2%) did not keep the vaccine refrigerated. The vaccine was well-tolerated and only 14 (8.9%) had one or more minor side effects. Of 59 (38%) who had received injectable typhoid vaccine previously, all preferred oral versus injectable vaccine, and reported moderate-to-severe side effects with the injectable form. Until a single-dose, oral typhoid vaccine is available, Ty21a is an attractive option. To achieve maximum efficacy, the importance of compliance should be emphasized.

Primary actinomycotic endocarditis: case report and review

Endocarditis due to Actinomyces species for which a portal of entry cannot be identified is extremely rare. We present a case of primary endocarditis due to Actinomyces israelii with an unknown portal of entry and review seven similar cases reported in the literature since 1939. The disease predominantly affects males. Clinical features are similar to those of bacterial endocarditis due to other organisms. Penicillin remains the drug of choice for treatment of this condition. The optimal duration of treatment has not yet been determined; however, with early diagnosis and appropriate antimicrobial therapy, the prognosis is good.

Activation of 5-HT2 receptors facilitates depolarization of neocortical neurons by N-methyl-D-aspartate

The interaction between serotonin and excitatory amino acid agonists at rat neocortical neurons was investigated using the grease-gap recording method. Depolarization evoked by 50 microM N-methyl-D-aspartate was dose dependently facilitated by serotonin (5-HT) (1 to 100 microM) giving a bell-shaped dose-response curve with maximum enhancement at 30 microM. In contrast, quisqualate and kainate depolarizations were not enhanced. Subnanomolar concentrations of methysergide, ritanserin and spiperone, but not ICS 205-930, attenuated the 5-HT enhancement, compatible with 5-HT2, but not 5-HT1 or 5-HT3 receptor subtype involvement. Enhancement was observed with 5-HT2 receptor agonists, whereas 5-HT1 receptor subtype agonists had either no effect (1B and 1C) or reduced (1A) the N-methyl-D-aspartate depolarization. Scopolamine and prazosin reduced the N-methyl-D-aspartate depolarization and blocked facilitation induced by carbachol and phenylephrine, but not that due to 5-HT. Tetrodotoxin reduced the N-methyl-D-aspartate depolarization, but the facilitation by 5-HT persisted. Activators of protein kinase C (phorbol diacetate and 1-oleoyl-2-acetyl-sn-glycerol) did not mimic the serotonin facilitation. We conclude that serotonin enhances N-methyl-D-aspartate depolarization of rat cortical neurons through activation of 5-HT2 receptors, however the cellular mechanism underlying the facilitation remains to be established.

Assembly of hepatic gap junctions. Topography and distribution of connexin 32 in intracellular and plasma membranes determined using sequence-specific antibodies

The subcellular distribution in rat liver and the topography in intracellular and plasma membranes of connexin 32, a major protein component of gap junctions, was studied using sequence-specific anti-peptide antibodies generated to extracellular and intracellular domains of the protein. The distribution of connexin 32 in liver analyzed using SDS-polyacrylamide gel electrophoresis and Western blotting showed the relative protein levels in the subcellular fractions to be: lateral plasma membranes > Golgi membranes > sinusoidal plasma membranes > lysosomes. Low amounts of connexin 32 were detected in microsomes, endosomes, and bile canalicular plasma membranes. Six highly conserved cysteine residues are located in the amino acid sequences comprising the two extracellular loops of all connexins thus far isolated, and these loops are positioned to extend the channel in the lipid bilayers across the intercellular region of the gap junction. In the present work, the intramolecular disulfide bonds linking the extracellular loops in gap junctions were shown to be present in connexins located in plasma membranes, Golgi, and a microsomal fraction, and it was concluded that the disulfide linkages were formed in the endoplasmic reticulum. In addition, immature configurations of connexin 32, probably occurring during membrane insertion, were detected in liver microsomal fractions. The results contribute to charting of the biogenetic routes followed by connexins in hepatocytes and the general mechanisms of gap junction assembly.

The effect of interleukin-1 on cytokine gene expression in cultured human articular chondrocytes analyzed by messenger RNA phenotyping

OBJECTIVE

To investigate the pattern of cytokine gene expression in human articular chondrocytes in culture in response to interleukin-1 beta (IL-1 beta). The effect of serum and variations in culture conditions was also studied.

METHODS

Messenger RNA was extracted from cells, reverse-transcribed to complementary DNA, and amplified by the polymerase chain reaction (PCR), using specific oligonucleotide primers. The PCR products were validated by restriction analysis with specific enzymes and by Southern blot analysis.

RESULTS

In cultured articular chondrocytes, IL-1 beta, IL-1 alpha, granulocyte colony-stimulating factor (CSF), and granulocyte-macrophage CSF cytokine genes were expressed only after induction by IL-1 beta. However, IL-6, IL-8, and macrophage CSF genes were expressed constitutively. The expression of IL-1 beta was dose and time dependent.

CONCLUSION

Using PCR, it was possible to demonstrate gene expression for several cytokines in human articular chondrocytes in culture. It was evident that some cytokine genes were expressed constitutively and some were inducible by IL-1 beta.

A case of bacteremia due to resistant Streptococcus pneumoniae

Streptococcus pneumoniae isolates with varying degrees of resistance to penicillin have been described. Strains that are highly resistant to penicillin (MIC, greater than 1 microgram/mL) and that are resistant to multiple antibiotics have been reported primarily in South Africa and Spain. We report a case of an adult patient with bacteremia due to S. pneumoniae that was highly resistant to penicillin (MIC, 4 micrograms/mL) and resistant to erythromycin, clindamycin, chloramphenicol, and co-trimoxazole who was successfully treated with vancomycin.

Bradykinin stimulates the production of prostaglandin E2 and interleukin-6 in human osteoblast-like cells

The effect of bradykinin (BK) on proteinase activity, prostaglandin synthesis, and the production of interleukin-6 (IL-6) was investigated in cultures of human osteoblast-like cells. Bradykinin had no effect on stromelysin activity and plasminogen activator activity produced by human osteoblast-like cells. However, BK stimulated the production of prostaglandin E2, an effect that was markedly enhanced by pre-incubation with recombinant interleukin-1 alpha (rhIL-1 alpha), but was apparently unaffected by BK receptor antagonists types 1 and 2. Bradykinin stimulated the intracellular accumulation of total inositol phosphates suggesting that its effects were mediated by stimulation of phosphoinositide metabolism. Bradykinin within the dose range of 10(-11)-10(-5) M also significantly stimulated the production of IL-6. Bradykinin may, therefore, mediate a variety of responses in bone under both physiological and pathological conditions.

Disease profile in respect of health services of Upazila health complex

This study was carried out to identify the disease profile in relation to medical services at upazila health complex. Thirty different types of diseases were identified. Diarrhoeal diseases were found to be highest (53%), the second highest was intestinal worms (44%). About ninety seven percent patient attended the OPD and only 2% were attended in the emergency Department. On average 172 patients were admitted per month and the highest of admission was found in the months of September and October. The average length of stay in the hospital was 11.6 days. Among the patients admitted 55% were male, and 45 were female. 5% pregnant mothers attended in U.H.C. for antenatal checkup and 2% mother were admitted into the hospital after delivery. Metronidazole was the drug of highest consumption followed by B-Complex and Penicillin.

The regulation of connective tissue metabolism by vasoactive intestinal polypeptide

Immunohistochemical studies have confirmed the innervation of bone with neuropeptidergic neurons containing vasoactive intestinal polypeptide (VIP), substance P (SP) and calcitonin gene-related peptide (CGRP). In this study, we report effects of VIP on connective tissue cell metabolism. VIP stimulated PGE2 production in human articular chondrocytes, human osteoblast-like cells and human synovial cells, however, stromelysin production was unaffected. VIP also stimulated cAMP production in human osteoblast-like cells, but not in human articular chondrocytes or synovial cells. These findings are suggestive of a role of VIP in connective tissue cell metabolism which may contribute to the inflammatory processes of arthritis.

Topography of connexin32 in rat liver gap junctions. Evidence for an intramolecular disulphide linkage connecting the two extracellular peptide loops

A range of anti-peptide antibodies directed towards selected amino acid sequences of connexin32 was prepared and characterised. The site-directed antibodies that identified connexin32 were used to study by immunolocalization and by proteolytic treatment of intact and split gap junctions the arrangement of the protein in the membrane. These studies reinforce models of connexin topography in which the polypeptide traverses the junctional membrane four times, with the amino and carboxyl termini cytoplasmically located. The four transmembrane domains were shown to be linked by two extracellular loops with a single intracellular loop connecting the second and third transmembrane domains. Evidence is presented to show that the two extracellular domains of connexin32, which are important for intercellular adhesion and the insulated bridging of the extracellular space by channels allowing cell-cell communication across the gap junction, are connected by disulphide bond(s). The studies lead to a more detailed two-dimensional model of connexin32 in the membrane, incorporating the favoured theoretical arrangement of disulphide bonds at the extracellular domain of connexin32.

Self care in health

The study "self care" was conducted in two Unions of one Upazila to assess prevalence, component and outcome of popular "self care" and their decision making process. Head of the family (500) and wives of the head of the family (500) were interviewed on alternate basis by trained interviewers on structured pretested questionnaire. Self care for remedial measure was universally practiced. Initial step related to treatment of diseases were "wait and see" (71.8%), "Self care" (18.4%), "Doctor/Homeopath" (9.8%). Self care was practiced by majority of the people in all other components. Those who reported "wait and see" as their first choice to deal with disease, about 79% waited for one day, 21% for two days. Education and income was found significant with practice of self care.

Diagnostic immunohistochemistry: current applications and future directions

In this review, the applications of enzyme immunohistochemistry in diagnostic pathology are discussed. Antibodies for diagnostic use are grouped into eight categories, viz, antibodies for tumour typing, for lymphocyte antigens, to hormones, peptides, amines and hormone receptors, to oncofetal antigens, to oncogenes and their products, to cell proliferation antigens, to infectious agents and for the study of glomerular diseases. The practical applications of these antibodies are reviewed with particular emphasis on the use of antibody panels for the identification of anaplastic round cell tumour in adults and children and of spindle cell neoplasms. Future directions for immunohistochemical techniques include their interphase with molecular biology and their applications in immunoelectron microscopy, in in-situ hybridisation procedures, in automation of routine staining and in image analyses.