Water and electrolyte salvage in an animal model of dehydration and malnutrition

BACKGROUND AND AIM: Recently, a new oral rehydration solution (ORS) called Resomal has been designed specifically for children with severe malnutrition. The aim of this study was to assess the effect of malnutrition on renal and intestinal responses to dehydration, and to compare intestinal water and electrolyte absorption from Resomal and from the standard World Health Organization-Oral Rehydration Solution (WHO-ORS). METHOD: Malnutrition was achieved in a rabbit model by feeding the animals daily for 30 days with half the amount of food that a well-nourished group of control animals had consumed on the previous day. Dehydration was achieved by water deprivation for 46 hours in both control and malnourished rabbits. At 46 hours, dehydration was assessed by changes in body weight, urinary volume and osmolarity, and blood urea nitrogen concentration. At that time active colonic and jejunal mucosal electrolyte transport in Ussing chambers was also measured. Small intestinal absorption of water, sodium, and potassium was measured in vivo during intestinal perfusion of the two ORSs and in vitro by measurement of mucosal electrogenic glucose-stimulated sodium absorption across intestinal patches. RESULTS: Compared to controls (C), well-nourished but dehydrated (C+D) animals lost 12% of their body weight, with an 87% reduction in urine volume, a 110% increase in urine osmolality, and a 94% increase in blood urea nitrogen. In the colon of C+D animals, short-circuit current (Isc) and net sodium transepithelial flux (JNa+ net) were increased. Almost identical results were obtained in malnourished and dehydrated (M+D) animals. In the jejunum, net in vivo absorption of water (JWater), sodium (JNa+), and potassium (JK+) were increased during standard ORS infusion in both dehydrated groups. During Resomal infusion, water absorption was the same as seen with WHO-ORS, but sodium absorption was reduced, and potassium absorption was increased in both well-nourished and malnourished dehydrated animals. In vitro, compared to controls, the glucose-stimulated short-circuit current (DeltaIsc), JNa+ net and G were increased in both dehydrated groups. CONCLUSION: During experimental dehydration, the kidney and large intestine salvage water and electrolytes, thus reducing the consequences of dehydration. These findings indicate that jejunal water absorption from Resomal and WHO-ORS is increased during dehydration, but Resomal allows for less sodium and more potassium to be absorbed, both in well-nourished and malnourished dehydrated rabbits.     

The proteome expression patterns in adult<Emphasis Type="Italic"> Ascaris suum</Emphasis> under exposure to aerobic/anaerobic environments analyzed by two-dimensional electrophoresis

We investigated the protein expression patterns (the proteome) in adult Ascaris suum under exposure to aerobic and anaerobic environments in vitro using two-dimensional polyacrylamide gel electrophoresis. Adult A. suum were cultured in RPMI-1640 in the absence of oxygen (anaerobic) or in its presence (aerobic), and whole worm extracts and their excretory-secretory (ES) products were prepared for protein analysis. More than 200 protein spots resolved in two-dimensional gels. A comparison of aerobic versus anaerobic cultures revealed two aerobic and three anaerobic specific spots differentially expressed in adult worm extracts. ES products released during aerobic/anaerobic cultures also exhibited one aerobic and seven anaerobic specific spots in two-dimensional maps. One of the anaerobic specific protein spot was analyzed for its internal amino acid sequence (1-LLAFELAPHGIR-12; 1-VNTVNPGAVD-10) and the protein was predicted to be a putative dehydrogenase. These findings suggest that the availability of oxygen or its absence in the environment may influence protein expression patterns in parasitic nematodes.     

Differential amplification and quantitation of Marek's disease viruses using real-time polymerase chain reaction

Quantitative real-time PCR (qPCR) assays for the three serotypes of Marek's disease virus (MDV) have been developed. An internal control qPCR assay that detects chicken alpha2 (VI) collagen gene was also developed to allow quantitation of MDV. To reduce costs and time, the assays for MDV1 and the internal control were combined into a duplex assay. The sensitivity, specificity, precision, and reproducibility of each assay are reported. The MDV qPCR assays were specific to their target gene when compared using Australian field and vaccine strains of MDV and 10-100-fold more sensitive than standard PCR. Using DNA from infected spleen tissue, the lower limit of detection of total DNA (viral and host combined) was 0.025 ng for the MDV1 and collagen assays, and 0.25 ng for the HVT and MDV2 assays. All assays were found to be highly reproducible for Ct values, but less so for calculated concentrations. MDV1 and HVT were quantitated in spleen tissue of twenty experimentally infected chickens 7-35 days after infection. The relative abundance of MDV1 exhibited a clear peak at day 14 post-infection, whereas HVT displayed an increasing trend over the 35 days post-infection. The duplex assay was optimized such that it was able to accurately quantitate MDV1 in samples of very high, medium, and very low relative abundance of MDV1. These qPCR assays will be useful for reliable differentiation and quantitation of MDV for a range of research and industry applications.     

Zinc status in well nourished Bangladeshi children suffering from acute lower respiratory infection

This study was done to investigate the association of zinc status of well nourished Bangladeshi children with Acute Lower Respiratory Infection (ALRI). In this case control study, simultaneous estimation of serum and hair zinc was performed in 35 well nourished children, aged 6-60 months suffering from ALRI and 38 normal matched controls. Serum zinc was low in children suffering from ALRI as compared to control (90 +/- 51 pg/dL vs 176 +/- 98 pg/dL, OR: 6, 95% CI: 1.83, 19.66;P <0.05) children. Hair zinc was also found significantly low in children suffering from ALRI as compared to control (158 + 48 1g/g vs 247 154 pg/g, OR: 3, 95% CI: 1.46, 10.04, P < 0.05). We conclude that Bangladeshi children suffering from pneumonia, have decreased levels of serum and hair zinc.     

The international suicide prevention trial (interSePT): rationale and design of a trial comparing the relative ability of clozapine and olanzapine to reduce suicidal behavior in schizophrenia and schizoaffective patients

Suicidal behavior in patients with psychotic disorders represents a seriously undertreated life-threatening condition. The International Suicide Prevention Trial (InterSePT) is the first large-scale, prospective study designed to evaluate the potential of antipsychotic medications to reduce suicidal behaviors in patients with schizophrenia or schizoaffective disorder who are known to be at high risk for suicide. The unique challenges to study design and the solutions identified for the InterSePT study are described. These challenges included defining suicidal behavior in patients with psychosis, endpoint selection, determination of analytic strategy, and development of scales to assess suicidal behavior. Given the life-threatening nature of suicidal behavior, ethical considerations required that the design minimize suicide attempts and deaths. While the study focused primarily on treatment of suicide, opportunities were used to collect data in related areas of interest, including suicide risk factors, other efficacy measures (e.g., Positive and Negative Syndrome Scale, Covi Anxiety Scale, Calgary Depression Scale), adverse events, pharmacoeconomics, and pharmacogenetics. Because of the complexity of the design issues, a steering committee, suicide monitoring board, and publication committee were established to assist with their management.     

Oral tobacco cessation with UK resident Bangladeshi women: a community pilot investigation

Our objective was to establish the short-term outcomes for successful tobacco cessation of a programme offering UK resident Bangladeshi women chewing paan with tobacco nicotine replacement therapy (NRT) in addition to brief advice and encouragement alone. We used a short-term longitudinal, quasi-experimental study design, in the setting of two local authority housing estates in Tower Hamlets, London. Bangladeshi women volunteers were recruited following presentations to community groups. The volunteers were assigned, after matching for age, number of paan with tobacco chewed daily and medical screening, to receive one of two tobacco cessation interventions (NRT with brief encouragement and advice, and brief advice and encouragement alone). The main outcome measures were changes in tobacco use and nicotine dependence, assessed by questionnaire and intake measures, adverse effects, and withdrawal symptoms. In total, 130 volunteers were recruited. Their mean age was 42.5 years (SD = 11.3). Mean number of paan quid with tobacco chewed daily was 10.7 (SD = 9.3) and the average age of starting to add tobacco to paan was 24 years (SD = 12). Ninety-one percent completed the 4-week trial. We found that 19.5% had stopped tobacco use, of whom 22% had received NRT, and 17% brief advice and encouragement alone. The successful members of the NRT group made a significantly greater reduction in their salivary cotinine scores at final review compared to baseline. Oral pain was reported as a barrier to successful oral tobacco cessation by 62% of the volunteers at final review. We conclude that methods identified as helping tobacco smokers successfully stop smoking can be used with Bangladeshi women chewing paan with tobacco. More research is needed to investigate these short-term outcomes and to explore the particular barriers to successful cessation for this group such as oral pain.     

Dietary calcium intake in premenopausal Bangladeshi women: do socio-economic or physiological factors play a role?

OBJECTIVE: Evaluation of data on dietary calcium intake in premenopausal women of two socio-economic groups in Bangladesh. DESIGN: A cross sectional study. Three days dietary records were used to estimate habitual calcium intake. SETTING: Two regions of Bangladesh. The Dhaka city area and the Betagair Union in the sub-district Nandail, Mymensingh. SUBJECTS: A total of 191 subjects of two groups (low socio-economic group=group L, n=101 and high socio-economic group=group H, n=90) of Bangladeshi women aged 16-40 y. About 87% of the subjects were housewives and the rest 13% were distributed in other different professions. Each group consisted of three sub-groups (non-pregnant non-lactating=1, pregnant=2 and lactating=3). RESULTS:: The influence of socio-economic status on dietary intake of calcium (P<0.001) was observed in this study. The dietary intake of calcium was influenced by physiological status (PS) in high income group only (P<0.005). The mean dietary calcium intake was significantly higher (P&<0.005) in all sub-groups of this group compared with the corresponding sub-groups in low income group. Although in group H, 47% of subjects failed to meet even the lowest level (400-500 mg/day) of WHO recommended dietary allowances (RDA) of calcium for adult women. No subject in group L was found to meet the RDA level. Moreover, 63% of the women in group L had calcium intake lower than 200 mg/day. These figure could be more critical in both groups if we consider the recent USA-RDAs of calcium for adult women (1000 mg/day). The observed sources of dietary calcium were different in the two groups. CONCLUSIONS: The results of the study suggested that low calcium intake could reduce the bone accretion rates and increase the risk of osteoporosis in the subjects of the present study. Calcium rich food may be recommended for women in both groups.     

Environmental tobacco smoke and carotid arterial stiffness

BACKGROUND: Although active smoking acutely increases arterial stiffness, the association between arterial stiffness and chronic exposure to environmental tobacco smoke (ETS) has not been evaluated. We used baseline data from the Vitamin E Atherosclerosis Prevention Study to evaluate the association between ETS exposure and arterial stiffness among 227 healthy adult nonsmokers. METHODS: B-mode ultrasonograms of the common carotid artery were used to compute the carotid arterial wall stiffness index beta. Beta was compared by the number of sources and daily hours of ETS exposure. RESULTS: The carotid stiffness index beta was positively associated with age, body mass index (BMI), fasting glucose, and common carotid artery intima-media thickness (IMT). In the total sample, beta was not related to the number of ETS exposure sources. The carotid stiffness index beta increased with number of sources and daily hours of ETS in subjects with BMI > or =27.1 kg/m2 and IMT > or =0.707 mm. The association was not apparent in subjects with lower BMI or IMT (for number of ETS sources, interaction P values=0.006 and 0.01, respectively). For number of ETS sources, but not hours of exposure, positive associations were apparent among females (but not males) and among subjects > or =55 years old (but not younger subjects). CONCLUSIONS: These data indicate that arterial stiffness is adversely associated with ETS in a dose-dependent manner among individuals with higher BMI and greater carotid artery IMT.