Genetic background of diabetic and nondiabetic sibs in young Bangladeshis

The prevalence of diabetes mellitus in the young is higher in Bangladesh like other Asian developing nations. Albeit, undernutrition has been shown to be associated with diabetes in the young, not all such individuals are diabetic. Diabetes Mellitus is a multigenic disease. In IDDM, DR3/4 heterozygotes were shown to have a greatly increased risk of developing the disease, suggesting the concept of genetic factor(s) being involved in the development of diabetes. Therefore, this study was undertaken to determine the distribution of HLA class II alleles (DRB) and to identify the HLA associated risk for developing diabetes mellitus in the young Bangladeshis. A total of fifty individuals were investigated. Half of them (n=25) were diabetic patients, registered in BIRDEM and half the participants were their non-diabetic sibs. A genomic DNA PCR and Enzyme Linked Probe Hybridization Assay (ELPHA, Bio-test, Germany) was used to determine HLA class II alleles (DRB1, DRB 3, 4, 5) by in vitro amplification of DRB gene. Among all the sero-equivalent antigens found in the study subjects, the prevalence of DR15 (DR2) was overrepresented, both in the diabetic subjects and in their non-diabetic sibs. Moreover, compared with the non-diabetic group the diabetic patients showed higher frequency of DR15 alleles (39 and 25%) though the difference was not significant (chisq. 1.7, p>0.05). Next to DR15, DR4 was the most prevalent HLA-DRB gene found in the study population. Interestingly, the frequency of DR4 was higher in the diabetic than in the non-diabetic group (20 vs. 14%). The study showed that the DR15 and DR4 were the most prevalent in the study population. Moreover, DR7 though not very significant, was higher in non-diabetic compared to their diabetic sibs. Comparison between the diabetic and non-diabetic sibs could have been interesting and significant but we could not confirm our findings, possibly, due to small sample size. A study in a larger paired sample of unrelated population is also needed to substantiate our findings, and also to prove the susceptibility or resistant haplotype in the young diabetic subjects.

Increased hepatocyte growth factor content in rat stomach during omeprazole treatment

BACKGROUND AND AIMS

Hepatocyte growth factor (HGF) is a potent mitogen of gastric epithelial cells, and its production is stimulated during the healing of gastric mucosal lesions. In this study, the effect of a proton pump inhibitor, omeprazole, on the production and degradation of HGF in the stomach was examined to elucidate the mechanism of the omeprazole-induced acceleration of gastric mucosal healing.

METHODS

Indomethacin-induced gastric mucosal lesions were induced in rats with or without omeprazole pretreatment. HGF gene expression and the content of HGF was investigated in the rat stomach. HGF degradation by gastric juice was also tested.

RESULTS

In omeprazole-treated rats, the healing of gastric mucosal lesions was accelerated in comparison with those of untreated rats. Although omeprazole treatment did not enhance the indomethacin-induced increase in HGF gene expression, it significantly augmented the gastric HGF content. Furthermore, omeprazole increased the gastric content not only of the inactive but also of the active heterodimeric form of HGF, and this appeared to be due to the inhibition of the HGF degradation by gastric juice.

CONCLUSION

Omeprazole-induced acceleration of gastric mucosal healing may be mediated at least in part by the reduced degradation of HGF in the stomach.

Prevalence of infectious diseases and drug abuse among Bangladeshi workers

Individuals seeking jobs abroad need health fitness certificates before entering into those countries. Medical screening of 43,213 Bangladeshi job seekers (M/F: 42,290/923) was carried out in our reference center during the period August, 1994 to May, 1996. Albeit male predominance, they represented middle and lower middle socio-economic class of the population from all over the country. All were young adults (age: 27.05+/-3.56 years; mean+/-SD) applying for job visas to different Asian countries. Physical examination and laboratory investigations including markers for several infectious diseases and drugs of abuse were carried out as required by countries recruiting the workers. Serological tests revealed that 1,884 (4.4%) of individuals were positive for hepatitis B surface antigen (HBsAg), 737 (1.7%) for Treponema pallidum hemagglutination (TPHA) and only 83 (0.2%) for antibody to human immunodeficiency virus (anti-HIV). However, we could not confirm any case of infection with HIV. Chest X-ray suggestive of pulmonary tuberculosis was found in 162 (0.4%) and on blood film, malarial parasites could be observed only in 4 cases. Their urine analysis revealed the presence of opiates or cannabinoids in 471 (1.1%) individuals. HBsAg-positive cases (p = 0.003) and abuse of opiates (p = 0.024) or cannabinoids (p = 0.002) were significantly higher among males. TPHA reactivity and chest X-ray suggestive of tuberculosis were found to be higher among opiates (p = 0.002 and 0.027) and cannabinoids (p = 0.000 for both) abused as well as with increasing age (p = 0.000). These results may represent a cross-sectional view of the prevalence of different infectious diseases and abuse of drugs among the young adult population of Bangladesh.

Nitric oxide products degrade chondroitin sulfates

Nitric oxide (NO) is a potent endogenous vasodilator that is elevated in response to inflammation. Inflammation also produces high levels of superoxide, which combines with NO to produce peroxynitrite (PN). We have previously reported that NO degrades heparin and heparan sulfate under acidic conditions and that PN degrades hyaluronan (HA) at neutral pH. Heparin and HA are glycosaminoglycans (GAGs) widely distributed in the extracellular matrix of tissues. Disruption of intestinal GAGs, particularly the chondroitin sulfates, were linked to inflammatory bowel diseases. Chondroitin sulfate A (CSA), chondroitin sulfate B (CSB), and chondroitin sulfate C (CSC) are constituents of the basement membranes of many tissues, including the intestine. The purpose of this study is to determine whether the NO donor S-nitroso-N-acetylpenicillamine (SNAP) and PN can degrade chondroitin sulfates in vitro. The NO donor SNAP (2 mM, pH 4.0) or PN (5 mM, pH 7.4) was incubated for at least 1 week at 37 degrees C with CSA, CSB, or CSC. Breakdown of CSA, CSB, and CSC was assessed by gel filtration chromatography and compared with untreated controls. Percentage degradation was calculated based on the change in peak height compared to the control. SNAP treatment partially degraded CSB and CSC, whereas PN partially degraded all three chondroitin sulfates. Nitric oxide mediated degradation of GAGs, and particularly chondroitin sulfates, may be an important pathway of inflammatory tissue damage.

Detection of hepatitis B surface antigen in pregnant women attending a public hospital for delivery: implication for vaccination strategy in Bangladesh

Routine antenatal hepatitis B surface antigen (HBsAg) screening and immunization of risk babies is very effective in preventing perinatal transmission of hepatitis B virus (HBV). We studied 1,800 parturients attending a public hospital to assess the rationale for such vaccination in Bangladesh. In one in every 29 deliveries (63 of 1,800 or 3.5%), the mother was found to be HBsAg positive. All were asymptomatic and many (41 of 63 or 65%) without risk factors would remain undetected if HBsAg screening were performed on selected groups. Most of the HBsAg-positive mothers (54 of 63 or 85.7%) were found to be chronic carriers and 30.2% (19 of 63) were also hepatitis B e antigen (HBeAg) positive, indicating high infectivity. Although 23 cord blood were positive for HBsAg or HBeAg, none were positive for IgM antibody to hepatitis B core antigen (IgM anti-HBc), suggesting transplacental transmission of the antigens rather than intrauterine infection. These findings are discussed in relation to the cost-effectiveness of routine prenatal screening and immunization of risk babies compared with universal infant immunization.

Effect of aging on gastrin receptor gene expression in rat stomach

Gastrin is a pivotal humoral factor which regulates gastric acid secretion through its receptors. There is no report, however, concerning the age-related changes of gastrin receptor gene expression in the stomach. Northern blot analysis and in situ hybridization were performed to clarify the changes of gastrin receptor expression during the aging. In situ hybridization clarified that gastrin receptor mRNA was expressed mainly in enterochromaffin-like (ECL) cells in adult rat gastric mucosa. With aging, gastrin receptor gene expression in the stomach increased with the concomitant increase in histidine decarboxylase mRNA. Since histidine decarboxylase is a marker of gastric ECL cells, the augmented gastrin receptor mRNA in aged rats may be caused by the increased ECL cells in gastric mucosa during the aging.

Prevalence of Helicobacter pylori in asymptomatic population--a pilot serological study in Bangladesh

Epidemiological reports reveal that H. pylori is distributed among all population in the world. The present cross-sectional study was undertaken to see the H. pylori seroprevalence rates among the asymptomatic adults, as yet reportedly no such data available in Bangladesh. Serum samples were collected from 181 consecutive subjects who attended at the health check-up centre of Bangladesh Institute of Diabeties, Endocrine and Metabolic Disorders (BIRDEM), Dhaka, during the period of August to November 1995 for medical check up. The mean age of these subjects was 30.33 years (range 20-44 yrs). Incidentally all were male and belonged to average socioeconomic class. H. pylori specific IgG antibody level was assayed by an enzyme immunoassay kit ElAgen (Clone system). Among the 181 subjects, 166 (92%) had H. pylori specific antibodies and 15 (8%) were seronegative. No significant difference (p < 0.90) in seroprevalence rates was observed among different age groups. However, the results of higher seroprevalence rates of H. pylori infection in these asymptomatic adult population of Bangladesh are consistent with that of Africa and India.

Developmental gene expression of gastrin receptor in rat stomach

Gastrin, which is present in fetal plasma, may have important roles in the development of gastric mucosa, since it is not only a potent stimulator of gastric acid secretion but also a growth promoting factor. Gastrin regulates various cellular functions via its receptors on cell membrane. Therefore, in order to elucidate a role for gastrin in the development of gastrointestinal system during gestation, Northern blot analysis was performed. The results of the study suggested that gastrin receptor is mainly present on parietal cells. Furthermore, proton pump and gastrin receptor gene expressions in parietal cells were strongly stimulated by the administration of exogenous gastrin. In conclusion, gastrin may be involved in the developmental change of parietal cells through its receptors.

Case report: torsion of a gravid horn of a didelphic uterus

Acute abdominal pain during pregnancy presents a dilemma as signs and symptoms are often modified. Abdominal massage by traditional birth attendants (TBAs') during early labour is a common practice in the rural population, as it is perceived to give a soothening effect to the labouring mother. Many instances of abruptio placentae were reported in the past by this procedure, and in this case, the clinical picture presented as an abruptio placenta. Malpresentation and failure to progress were the indications for caesarean section despite the fetal demise. Severe post partum haemorrhage and failure to contract despite massive oxytocics resulted in the hysterectomy of the gravid horn, leaving the other horn intact.

Erythropoietin stimulates proliferation of rat-cultured gastric mucosal cells

Most anemic patients with chronic renal failure have gastric mucosal lesions. However, these gastric lesions are often improved after the administration of recombinant human erythropoietin (rHuEPO). We have used the rat gastric mucosal cell line RGM-1, to examine the possibility that rHuEPO might directly stimulate the growth of gastric mucosal cells in vitro. Our results show that rHuEPO dose-dependently increased [3H]thymidine incorporation into RGM-1 cells and their expression of c-myc gene. In addition, 125I-rHuEPO specifically bound to RGM-1 cells, and moreover, erythropoietin receptor gene expression was detected by RT-PCR. We conclude that rHuEPO has a direct growth-promoting effect on RGM-1 cells, suggesting possible usefulness of rHuEPO administration for the treatment of gastric mucosal damage in patients with chronic renal failure.

Prepubertal periodontitis: a genetic analysis

Genetic factors were recognized as possible predisposing factors in the etiopathogenesis of prepubertal periodontitis (PP). Consequently, the present work was carried out to determine the possible mode of inheritance and if there were any associated chromosomal aberrations in cases with PP. The study included 3 families with probands manifesting PP (the families included 18 individuals). Pedigree analysis was carried out as well as chromosomal analysis. The results pointed out to the possibility of new mutations arising due to various environmental factors (including the use of pesticides and their handling), in addition to a possible autosomal recessive inheritance. Chromosomal analysis showed no association between a certain chromosomal aberration and PP. An interesting finding was that a girl proband proved to be Xo female, i.e. a case of Turner's syndrome. This could be considered the first report of Turner's syndrome with PP.

Regulation of C gamma 3 expression. Role of switch in the allotype-associated variation of human serum IgG3 levels

Serum IgG3 levels are associated with G3m allotypes in humans. However, the molecular basis of this association has not been understood. In this study we have analyzed the biologic half-life, the secretion, the cell surface expression, the cytoplasmic content, and the mRNA expression of different allotypes. The biologic properties of the allotypes did not differ. However, the frequency of cells with membrane IgG3, cytoplasmic IgG3, and C gamma 3 mRNA was decreased in donors with a low serum IgG3, whereas the level of C gamma 3 mRNA expression in individual cells did not differ among cells of the different allotypes. As these findings indicated a pretranscriptional control of C gamma 3 expression, genomic DNA from donors with different allotypes were also studied. Despite the absence of gross, allotype-related differences in the I gamma 3 regions, we favor an upstream cis-element influencing C gamma 3 switching as the most likely explanation for variations in IgG3 serum levels.

Regulation of C gamma 3 expression. Role of switch in the allotype-associated variation of human serum IgG3 levels

Serum IgG3 levels are associated with G3m allotypes in humans. However, the molecular basis of this association has not been understood. In this study we have analyzed the biologic half-life, the secretion, the cell surface expression, the cytoplasmic content, and the mRNA expression of different allotypes. The biologic properties of the allotypes did not differ. However, the frequency of cells with membrane IgG3, cytoplasmic IgG3, and C gamma 3 mRNA was decreased in donors with a low serum IgG3, whereas the level of C gamma 3 mRNA expression in individual cells did not differ among cells of the different allotypes. As these findings indicated a pretranscriptional control of C gamma 3 expression, genomic DNA from donors with different allotypes were also studied. Despite the absence of gross, allotype-related differences in the I gamma 3 regions, we favor an upstream cis-element influencing C gamma 3 switching as the most likely explanation for variations in IgG3 serum levels.

Biological half-life of normal and truncated human IgG3 in scid mice

The fractional catabolic rate of IgG in the body is regulated with precision in order to maintain appropriate serum concentrations. We have investigated the turnover rate of normal human IgG3, a newly identified, naturally occurring, truncated form of IgG3 and a human-mouse chimeric IgG3 antibody in an immunodeficient mouse strain, C.B-17 (SCID), lacking endogenous Ig. The half-life of non-truncated, normal serum IgG3 as well as the chimeric antibody was about 7 days, whereas truncated IgG3 had a shorter half-life of about 5 days. Due to the inherent immune defect, the SCID mouse could represent a versatile animal model for the determination of turnover rates, inasmuch as an immune response will not be mounted against foreign antigens.

Transcription, translation and secretion of both IgA subclasses in polyclonally activated human lymphocytes

To analyze human IgA subclass-specific mRNA we have developed RNA probes for quantitation of alpha 1 and alpha 2 heavy chain constant region genes by solution hybridization. Under our assay conditions, we can detect as little as 3 pg of specific mRNA and there is less than 2% cross-reactivity between the two IgA subclasses. Using this method, the relative proportions of IgA1 and IgA2 mRNA in pokeweed mitogen (PWM)-stimulated cells were found to be 66% and 34%, respectively, while in the Epstein-Barr virus (EBV)-stimulated cells they were 77% and 23%, respectively. Cytoplasmic staining of the plasma cells and determination of IgA subclass distribution by flow cytometry revealed an almost even distribution of the two IgA subclasses as induced by both activators. The culture supernatant contained 72% IgA1 and 28% IgA2 after PWM stimulation, while EBV stimulation induced 85% IgA1 and 15% IgA2. This report thus describes a method for the quantitative analysis of IgA subclass-specific mRNA. Furthermore, we present evidence that in response to in vitro stimulation of peripheral blood lymphocytes by polyclonal activators the IgA-producing B cells not only synthesize both isotypes but also have the potential to secrete them.

Production of sterile transcripts of C gamma genes in an IgM-producing human neoplastic B cell line that switches to IgG-producing cells

A human neoplastic B cell line SSK41 that expresses IgM on its surface switches spontaneously to IgG-producing cells. The SSK41 line contains a single immunoglobulin heavy-chain locus, the constant region (C) genes of which retain the germline configuration. The IgG-producing SSK41 line was purified by sorting, and shown to have undergone S-S recombination with deletion of the C mu gene. This line produced secretory and membrane-bound forms of gamma-chain mRNA. From cDNA libraries of a mixed population of IgM+/IgG+ SSK41 cells, we have isolated cDNA clones encoding the mature membrane-bound and secretory forms of the mu and gamma 1 heavy chains, all of which share the same variable region sequence. cDNA clones containing the mature gamma 3 chain were identified as well. We also isolated cDNA clones containing C gamma 1 and C gamma 3 sterile transcripts from the SSK41 line. These sterile transcripts contained additional exon sequences designated 'I' which were localized upstream of the C gamma 1 and C gamma 3 switch regions and homologous to murine counterparts. The I sequences were precisely spliced to the 5' ends of the corresponding C gamma exon sequences. These features of germline CH transcripts, i.e. the isotype specificity to class switching, location of exons, and sequences per se, are highly conserved between man and mouse.