Evaluation of 4-methyl-2-[(2-methylbenzyl) amino]-1,3-thiazole-5-carboxylic acid against hyperglycemia, insulin sensitivity, and oxidative stress-induced inflammatory responses and ß-cell damage in the pancreas of streptozotocin-induced diabetic rats.

4-Methyl-2-[(2-methylbenzyl) amino]-1,3-thiazole-5-carboxylic acid (bioactive compound (BAC)), a novel thiazole derivative, is a xanthine oxidase inhibitor and free radical scavenging agent. Effects of BAC on hyperglycemia, insulin sensitivity, oxidative stress, and inflammatory mediators were evaluated in streptozotocin (STZ)-induced neonatal models of non-insulin-dependent diabetes mellitus (NIDDM) rats where NIDDM was induced in neonatal pups with single intraperitoneal injection of STZ (100 mg/kg). The effect of BAC (10 and 20 mg/kg, p.o.) for 3 weeks was evaluated by the determination of blood glucose, oral glucose tolerance test (OGTT), HbA1c level, insulin level, insulin sensitivity, and insulin resistance (IR). Furthermore, inflammatory mediators (tumor necrosis factor-alpha and interleukin-6) and oxidative stress were estimated in serum and pancreatic tissue, respectively. Significant alteration in the level of blood glucose, OGTT, HbA1c, insulin level, insulin sensitivity, in addition variation in the antioxidant status and inflammatory mediators, and alteration in histoarchitecture of pancreatic tissue confirmed the potential of BAC in STZ-induced neonatal models of NIDDM rats. Pretreatment with BAC restored the level of glucose by decreasing the IR and increasing the insulin sensitivity. Furthermore, BAC balanced the antioxidant status and preserved the inflammatory mediators. Histological studies of pancreatic tissues showed normal architecture after BAC administration to diabetic rats. Altogether, our results suggest that BAC successfully reduces the blood glucose level and possesses antioxidant as well as anti-inflammatory activities. This leads to decreased histological damage in diabetic pancreatic tissues, suggesting the possibility of future diabetes treatments.

Prevalence of colorectal diseases in immunological fecal occult blood test (I-FOBT) positive patients in a tertiary care hospital in Bangladesh.

Bleeding lesion anywhere in the GI tract can cause positive reaction to Immunological Fecal Occult Blood Test (FOBT). Although any colonic lesion can cause occult lower GI bleeding, relative frequency of this lesion not known. Guaic based tests require prior preparation and dietary restriction and less sensitive and specific than IFOBT for detection of occult bleeding .IFOBT is specific for human hemoglobin and is more sensitive and specific for detection of occult bleeding from any colonic lesion. Aim of this study was to diagnose occult gastrointestinal bleeding with positive IFOBT and the prevalence of colorectal disease in IFOBT positive patients in a tertiary care hospital in Bangladesh. This was a prospective cross sectional study conducted in Department of gastroenterology in collaboration with clinical pathology, BSMMU, Dhaka during the period of January 2009 to December 2009. In this study 200 patients meeting the inclusion criteria were included. Detailed clinical history and physical findings were recorded; FOBT was done on single stool specimen. Positive occult bleeding was confirmed in 90 patients of whom 80 patients underwent colonoscopy. The mean age of study population was 36.73±13.64 (range 16 to 72) years. At colonoscopy lesion were identified in 46(57.50%) patients, of which colonic polyp in12 (15%), colorectal cancer in 11(13.7%), inflammatory bowel disease in 3(3.75%), hemorrhoids and anal fissure in 7(8.75%), tuberculosis in 5(6.25%), and proctitis in 1(1.25%) cases. A positive IFOBT is more sensitive and specific test than other FOBT for detection of occult lower GI bleeding of colonic origin. In this study colorectal diseases were detected in 57.50% of the IFOBT positive patients, so IOBT can be used as an important diagnostic tool for detection of occult lower GI bleeding.

Nanotopography drives stem cell fate toward osteoblast differentiation through α1ß1 integrin signaling pathway.

The aim of our study was to investigate the osteoinductive potential of a titanium (Ti) surface with nanotopography, using mesenchymal stem cells (MSCs) and the mechanism involved in this phenomenon. Polished Ti discs were chemically treated with H2 SO4 /H2 O2 to yield nanotopography and rat MSCs were cultured under osteogenic and non-osteogenic conditions on both nanotopography and untreated polished (control) Ti surfaces. The nanotopography increased cell proliferation and alkaline phosphatase (Alp) activity and upregulated the gene expression of key bone markers of cells grown under both osteogenic and non-osteogenic conditions. Additionally, the gene expression of α1 and ß1 integrins was higher in cells grown on Ti with nanotopography under non-osteogeneic condition compared with control Ti surface. The higher gene expression of bone markers and Alp activity induced by Ti with nanotopography was reduced by obtustatin, an α1ß1 integrin inhibitor. These results indicate that α1ß1 integrin signaling pathway determines the osteoinductive effect of nanotopography on MSCs. This finding highlights a novel mechanism involved in nanosurface-mediated MSCs fate and may contribute to the development of new surface modifications aiming to accelerate and/or enhance the process of osseointegration.

Hospital management of severely malnourished children: comparison of locally adapted protocol with WHO protocol.

OBJECTIVES: To compare the effectiveness of locally adapted Institute of Child and Mother Health (ICMH) protocol with the WHO protocol for the management of severely malnourished children in Bangladesh. DESIGN: Quasi-experimental non-randomized clinical trial. SETTING: Hospital based. PARTICIPANTS: Severely malnourished children (2-59 mo) with weight for height<70% (n=60). INTERVENTION: Children treated with either WHO protocol (Group I, n=30) or ICMH protocol (Group II, n=30). OUTCOME VARIABLES: Clinical improvement, weight gain, time taken to achieve target weight gain, and mortality among the study subjects. RESULTS: Mean (SD) weight related to gain in Group I and Group II was 11.2 (4.1) and 11.1 (3.9) g/kg/day, respectively. The weight gain was not related to the age group or type of malnutrition. The time taken for edema to subside (7.3 d vs 8 d) and for improvement of appetite (6.5 d to 7.3 d vs 6.7 d to 8.4 d) was similar between the groups. The target weight gain was achieved in 28.3 (11.5) days in Group I against 27.9 (6.2) days in Group II (P=0.88). The mortality rate was 6.7% in each group. CONCLUSION: Treatment of severe malnutrition with locally adapted ICMH protocol using locally available foods is as efficacious as the WHO protocol.

Accumulation of iron and arsenic in the Chandina alluvium of the lower delta plain, Southeastern Bangladesh.

Accumulations of iron, manganese, and arsenic occur in the Chandina alluvium of southeastern Bangladesh within 2.5 m of the ground surface. These distinctive orange-brown horizons are subhorizontal and consistently occur within 1 m of the contact of the aerated (yellow-brown) and water-saturated (gray) sediment. Ferric oxyhydroxide precipitates that define the horizons form by oxidation of reduced iron in pore waters near the top of the saturated zone when exposed to air in the unsaturated sediment. Hydrous Fe-oxide has a high specific surface area and thus a high adsorption capacity that absorbs the bulk of arsenic also present in the reduced pore water, resulting in accumulations containing as much as 280 ppm arsenic. The steep redox gradient that characterizes the transition of saturated and unsaturated sediment also favors accumulation of manganese oxides in the oxidized sediment. Anomalous concentrations of phosphate and molybdenum also detected in the ferric oxyhydroxide-enriched sediment are attributed to sorption processes.

Asthma, atopic eczema and allergic rhino-conjunctivitis in school children.

International Study of Asthma and Allergies of Childhood (ISAAC) phase one study had already been completed in two age groups in 156 collaborating centers of 56 countries involving a total of 721601 children. Bangladesh did not participate earlier in this worldwide study. To determine the prevalence of asthma, allergic rhinitis and eczema in school children of Dhaka district using ISAAC protocol. A school based cross sectional study done in 2000 by using both written questionnaires (WQ) and video questionnaires (VQ). Students of class-VIII (13-14 years) filled up both the WQ and VQ and the parents of class I (6-7 years) filled up only the WQ on behalf of the students. Sixty five (6)5 primary schools and 39 high schools were randomly selected from all 19 thanas to cover equally both the urban and rural schools of the entire area of Dhaka district. A total of 6260 written questionnaires were eligible for the analysis (3029 form 6-7 years of class I and 3231 from 13-14 years of class VIII). In addition, the validated international video questionnaires were used for the older age group (3231). The symptoms of atopic diseases in the previous 12 months or ever in all children, both age groups, both sexes and in both urban and rural areas. The life time (ever) and 12-month period (recent) prevalence of three allergic conditions with 95% CI were as follows : wheezing 13.8% (12.9-14.6), 7.6% (6.9-8.2); allergic rhinitis 25.0% (23.9-26.1), 20.0% (19.1-21.1) and eczema 8.7% (CI 8.0-9.4), 6.5% (5.9-7.2). respectively. The prevalence of wheezing and other atopic features in both age groups of 6-7 years and 13-14 years showed higher features of recent wheeze in the younger children than in the older children, recent wheeze 9.1% Vs 6.1%; but the other atopic features were found lower in younger age group, recent rhinitis 16.3% Vs 23.5%, 0.001; conjunctivitis 6.4% Vs 8.3%, 0.001; recent eczema 6.0% Vs 7.1% 0.001. Male children were found to be more suffering from all types allergic conditions than their female peers: recent wheeze 9.0% Vs 5.9%, recent rhinitis 21.9% Vs 17.9%, recent allergic conjunctivitis 8.7% Vs 6.7% and recent eczema 6.8% Vs 6.2%). Though the prevalence of asthma and atopic eczema was lower than those of developed countries but still appeared to be a major health problem for our children. Allergic rhinitis was the commonest of all atopic problems in children. The younger children (6-7 years) were more likely to suffer from wheeze (asthma) but other allergic problems were more in older group of children (13-14 years). Male children were more prone to all types of allergic problems, whether wheeze or other atopic conditions, than the female peers.

The glutathione defense system in the pathogenesis of rheumatoid arthritis.

In order to assess a possible role of the natural glutathione defense system in the pathogenesis of rheumatoid arthritis (RA), serum reduced glutathione levels (GSH), glutathione reductase (GSR), glutathione S-transferase (GST), glutathione peroxidase (GSH-Px) and alkaline phosphatase (ALP) activities, lipid peroxidation (MDA content) and indexes of inflammation were evaluated in 58 rheumatic patients. Rheumatoid athritis was associated with significant depletion (ca. 50%) in GSH levels compared with normal control subjects. Serum levels of the detoxifying enzymes GSR and GSH-Px decreased by ca. 50% and 45%, respectively, whereas a threefold increase in the activity of GST was observed. A 1.2-fold increase in ALP was observed in patients with RA. These effects were accompanied by a 3.1-fold increase in serum MDA content. The MDA content was higher in RA patients who were seropositive for rheumatoid factor as well as positive for C-reactive proteins. The erythrocyte sedimentation rate for all patients with RA was approximately 13.8-fold higher than for the control group, and was higher among RA patients who were positive for C-reactive proteins and exhibited seropositivity for rheumatoid factor. Patients with RA receiving gold therapy exhibited significantly lower MDA levels whereas all other factors that were measured were not effected. The results support a hypothesis that defense mechanisms against reactive oxygen species are impaired in RA.

Short report: Leishmania DNA in Phlebotomus and Sergentomyia species during a kala-azar epidemic.

The presence of Leishmania donovani DNA in sand flies caught in Indian kala-azar patients' dwellings during the epidemic of 1990-1992 was studied using the polymerase chain reaction (PCR). Amplification of miniexon-derived RNA genes and gpG3 mRNA was achieved in single Phlebotomus argentipes, P. papatasi, and Sergentomyia babu flies. The data suggest the possible involvement of multiple sandfly species in kala-azar transmission.

A 45,000-M(r) glycoprotein in the Sendai virus envelope triggers virus-cell fusion.

Sendai virus envelopes devoid of hemagglutinin-neuraminidase but containing the fusion protein (F-virosomes) were prepared. F-virosomes exhibited discernible serine protease activity at neutral pH. Electrophoretic analysis of the protein profile of the F-virosomes under nonreducing conditions, by both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing, led to the identification of a previously unknown glycoprotein with a relative molecular weight of 45,000 (45K protein) associated with the F protein. The identity of the 45K protein, as distinct from F protein, was established by Western blot analysis with F- and 45K-specific antibodies. This 45K protein forms a nexus with the F protein through noncovalent hydrophobic interactions, as proved by its sensitivity to urea treatment, and it is essential for the proteolytic activity of the F-virosomes as well as for the fusion of the viral envelope with host cell membrane. N-terminal sequence analysis (first 11 amino acids) of this protein showed strong homology (> 90%) to flavivirus NS3 serine proteases but no similarity to any of the Sendai viral proteins. On the basis of the N-terminal sequence, oligonucleotides were designed corresponding to the sense and antisense DNA sequences. Dot blot hybridization and primer extension with these oligonucleotides with the viral and the host genome confirmed the host origin of this protein. Further, the limited proteolytic digestion of the target membrane resulted in significant inhibition of viral fusion with it. On the basis of these results, we postulate a model for the molecular mechanism of F protein-induced membrane fusion, which may provide a rationale for other paramyxoviruses.

Protective effects of antioxidants against uraemia-induced lipid peroxidation and glutathione depletion in humans.

The effects of uraemias and antioxidant therapy for 40 days with vitamin A, vitamin C and vitamin E on blood and erythrocyte sulfhydryl (glutathione, GSH) content and on erythrocyte glutathione-S transferase (GST), glutathione reductase (GSR) and glutathione peroxidase activities were studied in six uraemic patients maintained on haemodialysis. In addition, the effect of antioxidant therapy on erythrocyte lipid peroxidation was determined, and erythrocyte haemoglobin content was measured. Uraemic patients in dialysis exhibited significant decreases in blood and erythrocyte GSH content as well as significant decreases in the activities of GST, GSR and GSH-peroxidase relative to control subjects. Furthermore, the uraemic patients had elevated erythrocyte malondialdehyde levels. Blood and erythrocyte GSH content from uraemic patients was significantly elevated after 20 days of antioxidant treatment and remained elevated thereafter throughout the remaining 20 days of the study (130% and 173%, respectively). Antioxidant therapy also produced significant increases in GSR and GSH-peroxidase activities after 20 days of treatment which remained relatively constant thereafter. No significant change in GST activity was observed. Erythrocyte malondialdehyde levels, as an index of oxidative tissue damage, exhibited a significant decrease (70%) in the patients after 40 days of antioxidant therapy. A gradual increase in erythrocyte haemoglobin content was observed following treatment of the uraemic subjects (45% at day 40). The results suggest that antioxidant therapy may protect against oxidative stress associated with uraemia.

Detection of Leishmania in the blood of early kala-azar patients with the aid of the polymerase chain reaction.

Samples from 39 patients with symptoms suggestive of early visceral leishmaniasis were independently assayed by microscopy of tissue smears, enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) of blood deoxyribonucleic acid. Of these patients, 19 were confirmed as positive or negative by all 3 tests; 11 patients (28%) negative by smear were positive by ELISA and PCR; and 7 (18%) were positive by PCR alone. These results demonstrate the high sensitivity of the non-invasive PCR and, to a smaller extent, ELISA, in the early diagnosis of visceral leishmaniasis.

Enzymatic amplification of mini-exon-derived RNA gene spacers of Leishmania donovani: primers and probes for DNA diagnosis.

The multicopy mini-exon-derived RNA (med RNA) locus of Leishmania donovani was enzymatically amplified by the polymerase chain reaction (PCR). The major 180 bp PCR product contained conserved med RNA gene sequences flanking the variable intergenic spacer from the med RNA gene tandem repeat. The oligonucleotide primers cross-reacted with other Leishmania species. In serial dilution experiments, positivity in the PCR assay was observed down to the genomic DNA equivalent of less than a single Leishmania cell. When the major PCR products from Indian L. donovani isolates were cloned and used as probes in dot hybridization analyses, they discriminated between L. donovani and L. amazonensis, L. major and L. infantum under high stringency conditions. DNA from spleen biopsies and blood samples of confirmed kala azar patients was positive, as were two skin biopsies from patients with post-kala azar dermal leishmaniasis (PKDL). These observations demonstrate that PCR amplification of med RNA intergenic spacers is sufficiently sensitive for clinical diagnosis of kala azar and PKDL, and furthermore, that cloned intergenic spacer probes may be useful for identification and classification of L. donovani.

Rapid and sensitive detection of Leishmania kinetoplast DNA from spleen and blood samples of kala-azar patients.

Following sequence analysis of a Leishmania donovani kinetoplast DNA (kDNA) minicircle, we have developed synthetic oligonucleotides for use in the polymerase chain reaction (PCR). With these primers, we have amplified L. donovani kDNA from splenic aspirates and blood samples taken from kala-azar patients. Treatment of the samples for PCR requires only limited DNA purification by lysis in SDS, digestion with proteinase K, phenol extraction and ethanol precipitation of the resulting nucleic acid. We have obtained amplified product routinely with DNA prepared from the equivalent of 2.5-25 microliters of splenic aspirate or of 50-500 microliters of blood from infected patients. In dilution experiments a visible product has been obtained on amplification of DNA from the equivalent of 2.5 x 10(-7) microliters of splenic material. We therefore propose the amplification of L. donovani kDNA by PCR as a rapid and highly sensitive method for the diagnosis of kala-azar.

Endrin-induced histopathological changes and lipid peroxidation in livers and kidneys of rats, mice, guinea pigs and hamsters.

Endrin toxicity may be due to an oxidative stress associated with increased lipid peroxidation, decreased glutathione content, and inhibition of glutathione peroxidase activity. Extensive interspecies variability exists in sensitivity towards endrin. Therefore, histopathological changes and lipid peroxidation in the livers and kidneys of rats, mice, hamsters, and guinea pigs were examined 24 hr after the administration of 4 mg endrin/kg body weight orally in corn oil. Degeneration and necrotic changes with inflammatory cell infiltration were observed in livers and kidneys, and interspecies variability occurred. Fatty changes in the form of hepatic foam cells with cytoplasmic vacuolation were present. Lipofuscin pigments, associated with lipid peroxidation, were observed in hepatocytes and Kupffer cells. These histopathological conditions were prevented in rats which had been pretreated with butylated hydroxyanisole, vitamins E and C, or cysteine, antioxidants and free radical scavengers which have previously been shown to inhibit lipid peroxidation. The extent of endrin-induced lipid peroxidation correlated well with the degree of histopathological changes. Thus, histological changes consistent with the induction of an oxidative stress were observed following the administration of endrin to various animal species.

Protective effects of antioxidants against endrin-induced lipid peroxidation, glutathione depletion, and lethality in rats.

Endrin depletes glutathione levels and induces lipid peroxidation in various species of animals. We have, therefore, examined the effect of antioxidants on these parameters in endrin-treated rats. Butylated hydroxyanisole (BHA), vitamin E, vitamin C, and the glutathione precursor cysteine significantly inhibited hepatic glutathione depletion and lipid peroxidation induced by 4 mg endrin/kg body weight. Furthermore, these antioxidants provided partial protection against lethality produced by 8 mg endrin/kg body weight. These results suggest but do not prove that free radical-mediated lipid peroxidation and glutathione depletion may be involved in the toxic manifestations of endrin.

Endrin-induced depletion of glutathione and inhibition of glutathione peroxidase activity in rats.

1. Recent studies have shown that endrin induces lipid peroxidation and may produce toxicity through an oxidative stress. We have therefore examined the effect of endrin administration to rats on glutathione content and the activities of glutathione metabolizing enzymes. 2. The oral administration of endrin resulted in dose- and time-dependent decreases in hepatic and renal glutathione content with maximum depletion (90%) occurring in liver at approximately 24 hr post-treatment. 3. Decreases in glutathione content were also observed in lung, brain, spleen and heart. 4. Endrin (4 mg/kg) decreased selenium dependent glutathione peroxidase activity in liver and kidney by 64 and 50%, respectively, while small increases were observed in the activities of glutathione reductase and glutathione S-transferase. 5. The toxicity of endrin may be at least in part related to oxidative tissue damage associated with depletion of glutathione and inhibition of glutathione peroxidase activity.

Comparative effects of pair-feeding and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on various biochemical parameters in female rats.

Hypophagia is a common characteristic of the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and may be responsible for some of the toxic manifestations. Pair-feeding has been used in control animals to compensate for the hypophagia, but relatively few studies have assessed biochemical changes associated with pair-feeding versus weight loss induced by TCDD. Rats were treated with TCDD and killed 7 days post-treatment while pair-fed animals received an amount of diet equivalent to TCDD-treated partner animals. Ad libitum-fed rats were also used. No correlations were seen in altered calcium and iron homeostasis between pair-feeding and TCDD administration relative to ad libitum-fed animals. Pair-feeding resulted in greater alterations than TCDD administration in the subcellular distribution of iron in mitochondria, microsomes and cytosol. Pair-feeding also resulted in greater accumulation of calcium in mitochondria and microsomes in pair-fed as compared to TCDD-treated animals. Greater lipid peroxidation was observed in whole liver and nuclei of rats receiving TCDD relative to pair-fed animals. A significantly greater incidence of DNA single strand breaks occurred in hepatic nuclei of TCDD-treated animals as compared to pair-fed and ad libitum-fed animals. Significantly greater inhibition of hepatic glutathione peroxidase activity and thymic involution were observed in TCDD treated animals as compared to the pair-fed group. Although some similarities existed between TCDD-treated animals and pair-fed rats, the overall biochemical changes which were observed following TCDD administration cannot be attributed to weight loss associated with hypophagia.

Comparative effects of BHA and ascorbic acid on the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in rats.

1. The abilities of BHA and ascorbic acid to prevent the toxic manifestations of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were examined in female Sprague-Dawley rats. 2. Rats treated with BHA were partially protected from TCDD-induced lipid peroxidation, inhibition of glutathione peroxidase activity, and losses in liver, thymus and body weights. 3. Ascorbic acid had no effect on TCDD-induced alterations in glutathione peroxidase and aryl hydrocarbon hydroxylase activities, or body, liver and thymus weight changes. Ascorbic acid was unable to protect against the lethality of TCDD. 4. Some of the toxic manifestations of TCDD may be mediated by reactive oxygen species and free radical processes.

Glutathione peroxidase and reactive oxygen species in TCDD-induced lipid peroxidation.

Previous studies have shown that high doses of TCDD induce hepatic lipid peroxidation and inhibit selenium dependent glutathione peroxidase (GSH-Px) activity. The dose dependent effects of TCDD on hepatic lipid peroxidation (malondialdehyde content) and GSH-Px activity were determined. A dose as low as 1 microgram/kg induced hepatic lipid peroxidation and inhibited GSH-Px. Based on the use of scavengers of reactive oxygen species, lipid peroxidation (malondialdehyde formation) by hepatic microsomes from both control and TCDD-treated rats appears to be due primarily to H2O2. The results indicate that superoxide, hydroxyl radical and singlet oxygen are also involved. The differences in the reactive oxygen species involved in microsomal lipid peroxidation between control and TCDD treated animals appear to be quantitative rather than qualitative. A 5.9-fold greater rate of malondialdehyde (MDA) formation by microsomes from TCDD treated animals occurred as compared to controls, while livers of TCDD rats had an MDA content that was 5.0-fold greater than the controls. These differences may be due in part to an enhanced production of H2O2 as well as a decrease in the activity of selenium dependent glutathione peroxidase which metabolizes H2O2.