Role of Anthropometric Indices in the Prediction of Non-alcoholic Fatty Liver Disease in a Rural Population of Bangladesh.

Non-alcoholic fatty liver disease (NAFLD) is found in one-fourth of the world population and its prevalence is rising. Screening of NAFLD in general population with ultrasonography (USG) is not a cost- effective approach. Alternative methods for prediction of NAFLD are needed. We conducted this study to assess whether basal metabolic index (BMI), waist circumference (WC), waist height ratio (WHtR) is useful for predicting NAFLD. This study was done in a village of Comilla District, Bangladesh from July 2019 to December 2019. Two hundred and nineteen (219) subjects with NAFLD detected on USG and 100 healthy controls without NAFLD were included in this study. The diagnosis of NAFLD was made on the basis of USG by a radiologist. BMI, WC, WHtR were calculated. The area under the curve (AUC) in the receiver operating characteristic (ROC) was calculated to assess the diagnostic ability of BMI, WC, and WHtR for predicting NAFLD. Sensitivity and specificity with optimal cut-off point was calculated. Data were entered into SPSS16for statistical analysis. Mean age in NAFLD group was 45.11±13.50 years. The AUROC values were 0.832, 0.763 and 0.771 for BMI, WC and WHtR respectively. The Cut-off values were 24.4 for BMI, 75.60 for WC and 0.54 for WHtR. Sensitivity and specificity were 80.24%and 79.12% for BMI, 82.34% and 80.45% for WC, 79.56% and 78.98% for WHtR respectively. ROC for BMI, WC and WHtR were above the diagonal line with high sensitivity and specificity. BMI, waist circumference, waist height ratio is useful for predicting NAFLD in rural Bangladeshi population. We can use these simple anthropometric indices as a screening tool for detection of NAFLD in primary health care set up.

Heavy Metals Accumulation in Vegetables and Its Consequences on Human Health in the Areas Influenced by Industrial Activities.

The degradation of the environment due to numerous industrial practices has emerged as a major issue globally, particularly in a country like Bangladesh. The present study dispenses information about heavy metal (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb) contamination in some frequently consumed vegetables, namely, ash pumpkin, potato, bitter gourd, buffalo spinach, snake gourd, and pointed gourd grown in an industrially prone location and their repercussion on consumers' health. Proton-induced X-ray emission (PIXE) technique was used as the major analytical tool to detect heavy metal concentrations. Mean concentration and the range of Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb in vegetables were detected (4.81 ± 2.79, 2.43-10.94), (497.57 ± 258.08, 181.24-886.67), (644.49 ± 298.40, 179.56-998.78), (38.88 ± 14.31, 18.88-60.12), (58.11 ± 12.58, 42.55-84.79), (137.24 ± 48.37, 71.99-208.98), (123.31 ± 63.62, 49.97-256.09), (8.09 ± 2.69, 4.29-14.94), and (4.16 ± 2.95, 1.22-9.98) mg/kg (dry weight basis), respectively. An extreme level of heavy metal contamination in vegetable samples was notified regarding the estimated metal pollution index (MPI) and Nemerow pollution index (P) value, which underpinned the health risk values. The estimated hazard index (HI) value stipulated high risk in all varieties of vegetables regardless of age group and cadmium (Cd) was found as the major contributor. Concerning the carcinogenic risk index (CR) for single elements, the value of Co, Ni, and Cr was approximated far above the USEPA threshold risk limit (CR>1E-04). Moreover, total carcinogenic risk (TCR) for all varieties of vegetables exceeded the safety threshold value for both the age group and children, in particular, were found most vulnerable. The outshot of the present study divulged associated health risks for the population group by the heavy metals via dietary intake of vegetables.

Elemental Analysis of Basella alba, Spinacia oleracea, Abelmoschus esculentus (L.), Ipomoea aquatica, Colocasia esculenta, Amaranthus dubius, and Raphanus sativus Vegetables Using the PIXE Technique in a Saline Region of Bangladesh, Rampal Area.

Particle-induced X-ray emission (PIXE) method was used in this present research to identify the elements present in selected vegetable samples to show the possible influence in the metal absorption by the vegetables grown in a saline region of Rampal area of Munshiganj District, Bangladesh. The data acquisition setup is calibrated using a 2.5-MeV proton beam in the current ranges of 5nA to 15nA. The detector was used to measure the X-rays emitted during the irradiation. Data acquisition system MAESTRO-32 was used to measure the spectrum picks, and concentration calculation has been done by GUPIX/DAN-32 software. The purpose of this study is to determine the concentration of heavy and trace elements in these samples and to give current information on their safety for consumption. The result shows that K, Ca, and Fe have the highest concentrations, while lead exhibits the lowest but alarming rates compared to reference materials. The findings were likened to IAEA-V-10, IAEA-359, SRM 1515 (apple leaf), and SRM 1573a (tomato leaf). The outcomes of the present investigation demonstrate that these samples are not devoid of health risks in intake.

Compact Color Biofinder (CoCoBi): Fast, Standoff, Sensitive Detection of Biomolecules and Polyaromatic Hydrocarbons for the Detection of Life.

We have developed a compact instrument called the "COmpact COlor BIofinder", or CoCoBi, for the standoff detection of biological materials and organics with polyaromatic hydrocarbons (PAHs) using a nondestructive approach in a wide area. The CoCoBi system uses a compact solid state, conductively cooled neodymium-doped yttrium aluminum garnet (Nd:YAG) nanosecond pulsed laser capable of simultaneously providing two excitation wavelengths, 355 and 532 nm, and a compact, sensitive-gated color complementary metal-oxide-semiconductor camera detector. The system is compact, portable, and determines the location of biological materials and organics with PAHs in an area 1590 cm2 wide, from a target distance of 3 m through live video using fast fluorescence signals. The CoCoBi system is highly sensitive and capable of detecting a PAH concentration below 1 part per billion from a distance of 1 m. The color images provide the simultaneous detection of various objects in the target area using shades of color and morphological features. We demonstrate that this unique feature successfully detected the biological remains present in a 150-million-year-old fossil buried in a fluorescent clay matrix. The CoCoBi was also successfully field-tested in Hawaiian ocean water during daylight hours for the detection of natural biological materials present in the ocean. The wide-area and video-speed imaging capabilities of CoCoBi for biodetection may be highly useful in future NASA rover-lander life detection missions.

Detecting Minerals and Organics Relevant to Planetary Exploration Using a Compact Portable Remote Raman System at 122 Meters.

Raman spectroscopy is a technique that can detect and characterize a range of molecular compounds such as water, water ice, water-bearing minerals, and organics of particular interest to planetary science. The detection and characterization of these molecular compounds, which are indications of habitability on planetary bodies, have become an important goal for planetary exploration missions spanning the solar system. Using a compact portable remote Raman system consisting of a 532 nm neodymium-doped yttrium aluminum garnet- (Nd:YAG-) pulsed laser, a 3-in. (7.62 cm) diameter mirror lens and a compact spectrograph with a miniature intensified charge coupled device (mini-ICCD), we were able to detect water (H2O), water ice (H2O-ice), CO2-ice, hydrous minerals, organics, nitrates, and an amino acid from a remote distance of 122 m in natural lighting conditions. To the best of our knowledge, this is the longest remote Raman detection using a compact system. The development of this uniquely compact portable remote Raman system is applicable to a range of solar system exploration missions including stationary landers for ocean worlds and lunar exploration, as they provide unambiguous detection of compounds indicative of life as well as resources necessary for further human exploration.

Childhood Adversities as Risk Factors and Persistence of Suicidal Behavior: A Descriptive Cross-Sectional Study.

Suicide is one of the important cause of death worldwide. The precise effect of childhood adversities as risk factors for the onset and persistence of suicidal behaviour are not well understood. A descriptive cross sectional study was carried out in the department of Psychiatry, Cumilla Medical College, Cumilla, Bangladesh. All cases were selected from patients attending at Cumilla Medical College hospital and Private Hospitals in Cumilla City from April 2017 to September 2018. We found out the association between childhood adversities and suicidal behaviour over the life course and delineated the types of suicidal behavior. Total 120 cases were included in the study. Respondents provided socio-demographic and diagnostic information, childhood adversities as well as an account of suicide-related thoughts and behaviours. A participation rate was 77.5% female. Of 120 suicidal behavior participants physical abuse was 2.5%, sexual abuse was 16.67%, parental death was 5%, parental divorce was 2.5%, other parental loss was 4.17%, family violence was 5%, physical illness was 1.67%, financial adversity was 3.33% and composite adversity was 59.16%. Among childhood adversities participants suicidal ideation was 70%, suicidal plans was 15.83%, suicidal attempts was 45%, ideators only proceeded to plans was 22.5%, ideation to attempt was 63.33%, planned attempts was 10.83% and impulsive attempts was 52.5%. Among suicidal behavior participant's psychiatric disorders were 65%. Where neurotic disorders were 17%, psychotic disorders were 13%, personality disorders were 44% and others disorder was 26%. Most of the suicidal behavior patients were female 77.5% and age group of 18-24 years. Childhood sexual abuse emerged as a particularly robust risk factor for suicide attempts in younger participants. Childhood physical and sexual abuse emerged as risk factors for the emergence and persistence of suicidal behaviour, especially in adolescence. Two or more childhood adversities were associated with a three fold higher risk of lifetime suicide attempts. Childhood adversities are main risk factors for the onset and persistence of suicidal behaviour. The risks being are the greatest in childhood, adolescence and early adult. A longitudinal follow-up study is required to give a more reliable in Bangladesh.

Standoff ultracompact micro-Raman sensor for planetary surface explorations.

We report the development of an innovative standoff ultracompact micro-Raman instrument that would solve some of the limitations of traditional micro-Raman systems to provide a superior instrument for future NASA missions. This active remote sensor system, based on a 532 nm laser and a miniature spectrometer, is capable of inspection and identification of minerals, organics, and biogenic materials within several centimeters (2-20 cm) at a high 10 µm resolution. The sensor system is based on inelastic (Raman) light scattering and laser-induced fluorescence. We report on micro-Raman spectroscopy development and demonstration of the standoff Raman measurements by acquiring Raman spectra in daylight at a 10 cm target distance with a small line-shaped laser spot size of 17.3 µm (width) by 5 mm (height).

Psychiatric Disorders in Drop out from Educational Attainment Attending Mental Health Facilities: A Descriptive Cross Sectional Study.

Studies of the impact of mental disorders on educational attainment are rare. Mental disorders, those beginning in childhood or adolescence may increase the risk of early drop out from education. The latter has been shown to have adverse life-course consequences on individuals such as greater demand on social welfare entitlements. A descriptive cross sectional study was carried out at the department of Psychiatry, Comilla Medical College, Comilla, Bangladesh. All cases were selected from patients attending at Comilla Medical College Hospital and Private Mental Health Facilities in Comilla City from March 2015 to February 2016. We found out the psychiatric disorders and socio-demographic status of patients with educational drop out over the early life course. A total of 50 dropout patients aged 10 to 30 years who fullfiled the enrolment criteria included in the study. Sociodemographic questionnaires, diagnostic information (DSM-5 and ICD-10) as well as an account of a various level of education were used as research instruments. The Frequency tables, summary tables and appropriate graphs were prepared to describe the population characteristics and study finding. The most of the psychiatric morbidity presents in male (62%) and age group of 18-24 years (54%). In this study, anxiety disorders was 8%, behaviour/ impulse control disorders was 8%, mood disorders was 16%, substance use disorders was 24%, schizophrenia spectrum disorders was 12% and composite psychiatric disorders was 32%. Among drop out patient's non- completion of primary education was 14%, non-completion of secondary education was 20%, non- completion of higher secondary education was 24%, not entry to tertiary education was 12% and non-completion of tertiary education was 30%. Among behaviour/impulse control disorders non-completion of primary education was 6%, substance use disorders non-completion of higher secondary education was 10%, mood disorder both non-completion of higher secondary education and non-completion of tertiary education were 6%. Among composite psychiatric disorders non-completion of secondary education, non-completion of higher secondary education and non-completion of tertiary education were 8%, 6% and 12% respectively. Onset of mental disorders and subsequent drop out from education was found in this study. Further multi-centered prospective and population-based studies should be designed to find out the exact situation.

"Standoff Biofinder" for Fast, Noncontact, Nondestructive, Large-Area Detection of Biological Materials for Planetary Exploration.

UNLABELLED: We developed a prototype instrument called the Standoff Biofinder, which can quickly locate biological material in a 500 cm(2) area from a 2 m standoff distance with a detection time of 0.1 s. All biogenic materials give strong fluorescence signals when excited with UV and visible lasers. In addition, the luminescence decay time of biogenic compounds is much shorter (<100 ns) than the micro- to millisecond decay time of transition metal ions and rare-earth ions in minerals and rocks. The Standoff Biofinder takes advantage of the short lifetime of biofluorescent materials to obtain real-time fluorescence images that show the locations of biological materials among luminescent minerals in a geological context. The Standoff Biofinder instrument will be useful for locating biological material during future NASA rover, lander, and crewed missions. Additionally, the instrument can be used for nondestructive detection of biological materials in unique samples, such as those obtained by sample return missions from the outer planets and asteroids. The Standoff Biofinder also has the capacity to detect microbes and bacteria on space instruments for planetary protection purposes. KEY WORDS: Standoff Biofinder-Luminescence-Time-resolved fluorescence-Biofluorescence-Planetary exploration-Planetary protection-Noncontact nondestructive biodetection. Astrobiology 16, 715-729.

Mineralogy and astrobiology detection using laser remote sensing instrument.

A multispectral instrument based on Raman, laser-induced fluorescence (LIF), laser-induced breakdown spectroscopy (LIBS), and a lidar system provides high-fidelity scientific investigations, scientific input, and science operation constraints in the context of planetary field campaigns with the Jupiter Europa Robotic Lander and Mars Sample Return mission opportunities. This instrument conducts scientific investigations analogous to investigations anticipated for missions to Mars and Jupiter's icy moons. This combined multispectral instrument is capable of performing Raman and fluorescence spectroscopy out to a >100 m target distance from the rover system and provides single-wavelength atmospheric profiling over long ranges (>20 km). In this article, we will reveal integrated remote Raman, LIF, and lidar technologies for use in robotic and lander-based planetary remote sensing applications. Discussions are focused on recently developed Raman, LIF, and lidar systems in addition to emphasizing surface water ice, surface and subsurface minerals, organics, biogenic, biomarker identification, atmospheric aerosols and clouds distributions, i.e., near-field atmospheric thin layers detection for next robotic-lander based instruments to measure all the above-mentioned parameters.

Experimental investigation of a multicylinder unmodified diesel engine performance, emission, and heat loss characteristics using different biodiesel blends: rollout of B10 in Malaysia.

This paper deals with the performance and emission analysis of a multicylinder diesel engine using biodiesel along with an in-depth analysis of the engine heat losses in different subsystems followed by the energy balance of all the energy flows from the engine. Energy balance analysis allows the designer to appraise the internal energy variations of a thermodynamic system as a function of ''energy flows" across the control volume as work or heat and also the enthalpies associated with the energy flows which are passing through these boundaries. Palm and coconut are the two most potential biodiesel feed stocks in this part of the world. The investigation was conducted in a four-cylinder diesel engine fuelled with 10% and 20% blends of palm and coconut biodiesels and compared with B5 at full load condition and in the speed range of 1000 to 4000 RPM. Among the all tested blends, palm blends seemed more promising in terms of engine performance, emission, and heat losses. The influence of heat losses on engine performance and emission has been discussed thoroughly in this paper.

Hard cocoa butter replacers from mango seed fat and palm stearin.

The blending effects of mango seed fat (MSF), extracted using supercritical fluid, and palm stearin (PS) to formulate hard cocoa butter replacers (CBRs), were investigated. The triglycerides (TG), thermal properties and solid fat content (SFC) of the formulated blends were determined using different chromatographic and thermal techniques. All the blends had three main TGs; namely, 1,3-dipalmitoyl-2-oleoylglycerol (POP) (8.6-17.7%), 1-palmitoyl-2-oleoyl-3-stearoyl-glycerol (POS) (12.6-19.6%), and 1,3-distearoyl-2-oleoyl-glycerol (SOS) (37.2-31.4%), with SOS being the major component. The melting peak temperatures gradually increased and shifted towards higher temperatures with PS. The crystallization onset temperatures increased, while the offset decreased with PS. The SFC did not drop to 0% at 37.5°C, which was shifted to 0% at and above 40°C for some blends. The studies revealed that CBRs could be prepared by blending MSF and PS, and they could be utilised by chocolate manufacturers in tropical countries.

Compact remote multisensing instrument for planetary surfaces and atmospheres characterization.

This paper describes a prototype feasibility demonstration system of a multipurpose Raman-fluorescence spectrograph and compact lidar system suitable for planetary sciences missions. The key measurement features of this instrument are its abilities to: i) detect minerals and organics at low levels in the dust constituents of surface, subsurface material and rocks on Mars, ii) determine the distribution of trace fluorescent ions with time-resolved fluorescence spectroscopy to learn about the geological conditions under which these minerals formed, iii) inspect material toxicity from a mobile robotic platform during local site characterization, iv) measure dust aerosol and cloud distributions, v) measure near-field atmospheric carbon dioxide, and vi) identify surface CO(2)-ice, surface water ice, and surface or subsurface methane hydrate. This prototype instrument and an improved follow-on design are described and have the capability for scientific investigations discussed above, to remotely investigate geological processes from a robotic platform at more than a 20-m radial distance with potential to go beyond 100 m. It also provides single wavelength (532 nm) aerosol/cloud profiling over very long ranges (>10 km with potential to 20 km). Measurement results obtained with this prototype unit from a robotic platform and calculated potential performance are presented in this paper.

Identification and characterization of Sall1-expressing cells present in the adult mouse kidney.

BACKGROUND: Sall1 is a transcription factor that best identifies stem cells present in the mouse embryonic kidney. Mutations in Sall1 gene in mice can lead to dysgenesis of kidney, while in humans it results in the Townes-Brocks syndrome, which is associated with the kidney agenesis. Unlike the embryonic kidney, Sall1 expression in the adult kidney is largely unknown. We hypothesized that similar to the embryonic kidney, Sall1 expression can identify stem cells present in the adult kidney. Accordingly in this study, we identified Sall1-expressing cells in the adult mouse kidney, determined their role in kidney regeneration following ischemia-reperfusion injury (IRI), and sought the effect of age on Sall1 expression. METHODS AND RESULTS: By immunofluorescence Sall1-expressing cells were identified in the proximal tubule at the cortico-medullary junction and constituted 0.5% of all tubular cells. Rare Sall1-positive cells were also identified in the outer cortex and distal tubules. Sall1 expression was not seen in the glomerular, interstitial, or vascular compartments. Following IRI, 90% of Sall1-expressing cells proliferated and 5% of Sall1-positive cells showed asymmetrical cell division with one of the two adjacent Sall1-positive cells incorporating chlorodeoxyuridine (CldU). Following IRI, there was an increase in Sall1 expression at 4 and 12 h, a decrease at 5 and 10 days, and baseline expression at day 30 by quantitative polymerase chain reaction (qRT-PCR) and Western blot analysis. There was no age-related change in Sall1 expression as determined by qRT-PCR, Western blot analysis, and immunofluorescence. CONCLUSIONS: We conclude that Sall1-expressing cells are present in the adult mouse kidney, predominantly in the proximal tubules. Sall1-expressing cells proliferate following IRI and some of the Sall1-positive cells undergo asymmetrical cell division. Therefore, Sall1 is a promising marker for identification of stem cells present in the adult mouse kidney.

Lidar backscatter signal recovery from phototransistor systematic effect by deconvolution.

Backscatter lidar detection systems have been designed and integrated at NASA Langley Research Center using IR heterojunction phototransistors. The design focused on maximizing the system signal-to-noise ratio rather than noise minimization. The detection systems have been validated using the Raman-shifted eye-safe aerosol lidar (REAL) at the National Center for Atmospheric Research. Incorporating such devices introduces some systematic effects in the form of blurring to the backscattered signals. Characterization of the detection system transfer function aided in recovering such effects by deconvolution. The transfer function was obtained by measuring and fitting the system impulse response using single-pole approximation. An iterative deconvolution algorithm was implemented in order to recover the system resolution, while maintaining high signal-to-noise ratio. Results indicated a full recovery of the lidar signal, with resolution matching avalanche photodiodes. Application of such a technique to atmospheric boundary and cloud layers data restores the range resolution, up to 60 m, and overcomes the blurring effects.

Autophagy delays apoptotic death in breast cancer cells following DNA damage.

Early signaling in camptothecin-treated MCF-7 cells followed an intrinsic pathway, but death was delayed and late events exhibited few hallmarks of apoptosis. BH3-only proteins, such as Noxa, Puma and BimEL, were activated and localized to mitochondrial sites within 24 h following drug exposure. However, caspase activity was low and death was unaffected by caspase inhibition. Transmission electron micrographs showed the presence of large vacuoles in drug-treated cells. An autophagic survival response has been attributed to MCF-7 cells following nutrient starvation or exposure to tamoxifen. Here, we show that autophagy also plays an important role in the delayed DNA damage response. Confocal microscopy revealed colocalization of mitochondria with large autophagic vacuoles and inhibitors of autophagy increased mitochondrial depolarization and caspase-9 activity, and accelerated cell death. Furthermore, downregulation of autophagy proteins, Beclin 1 and Atg7, unmasked a caspase-dependent, apoptotic response to DNA damage. We propose that a post-mitochondrial caspase cascade is delayed as a result of early disposal of damaged mitochondria within autophagosomes. Our data also suggest that the use of autophagy as a means of delaying apoptosis or prolonging survival may be characteristic of noninvasive breast tumor cells. These studies underscore a potential role for autophagy inhibitors in combination with conventional chemotherapeutic drugs in early breast cancer therapy.

N-3 fatty acids inhibit vascular calcification via the p38-mitogen-activated protein kinase and peroxisome proliferator-activated receptor-gamma pathways.

Fish oil supplementation is associated with lower risk of coronary artery disease in humans, and it has been shown to reduce ectopic calcification in an animal model. However, whether N-3 fatty acids, active ingredients of fish oil, have direct effects on calcification of vascular cells is not clear. In this report, we investigated the effects of eicosapentaenoic acid and docosahexaenoic acid (DHA) on osteoblastic differentiation and mineralization of calcifying vascular cells (CVCs), a subpopulation of bovine aortic medial cells that undergo osteoblastic differentiation and form calcified matrix in vitro. Results showed that N-3 fatty acids inhibited alkaline phosphatase (ALP) activity and mineralization of vascular cells, suggesting that they directly affect osteoblastic differentiation in vascular cells. By Western blot analysis, DHA activated p38-mitogen-activated protein kinase (MAPK) but not extracellular-regulated kinase (ERK) or Akt. An inhibitor of p38-MAPK partially reversed the inhibitory effects of DHA on osteoblastic differentiation and mineralization. Transient transfection experiments showed that DHA also activated peroxisome proliferator-activated receptor-gamma (PPAR-gamma). Both p38-MAPK activator and PPAR-gamma agonists reproduced the inhibitory effects of DHA on CVC mineralization. Pretreatment with DHA also inhibited interleukin-6-induced ALP activity and mineralization. Together, these results suggest that N-3 fatty acids directly inhibit vascular calcification, and that the inhibitory effects are mediated by the p38-MAPK and PPAR-gamma pathways.

Gallbladder Na+/H+ exchange activity is up-regulated prior to cholesterol crystal formation.

BACKGROUND: Gallbladder Na+ and H2O absorption are increased prior to gallstone formation and may promote cholesterol nucleation. Na+/H+ exchange (NHE) isoforms NHE2 and NHE3 are involved in gallbladder Na+ transport in prairie dogs. We examined whether increased gallbladder Na+ absorption observed during early gallstone formation is the result of NHE up-regulation. MATERIALS AND METHODS: Native gallbladder and primary cultures of gallbladder epithelial cells (GBECs) harvested from prairie dogs fed nonlithogenic (CON) or 1.2% cholesterol diet for varying lengths of time to induce cholesterol-saturated bile (PreCRYS), cholesterol crystals (CRYS), or gallstones (GS) were used. NHE activity was assessed by measuring dimethylamiloride-inhibitable 22Na+ uptake under H+ gradient in primary GBECs. HOE-694 was used to determine NHE2 and NHE3 contributions. NHE protein and mRNA expression were examined by Western and Northern blots, respectively. RESULTS: Gallbladder total NHE activity was 25.1 +/- 1.3 nmol mg protein(-1) min(-1) in the control and increased during gallstone formation peaking at the PreCRYS stage (98.4 +/- 3.9 nmol mg protein(-1) min(-1)). There was a shift in NHE activity from NHE2 to NHE3 as the animals progressed from no stones through the PreCRYS and CRYS stages to gallstones. The increase in NHE activity was partly caused by an increased Vmax without any change in K(Na)m. Both NHE2 and NHE3 protein increased moderately during the PreCRYS stage without increases in mRNA expression. CONCLUSIONS: Increased gallbladder Na+ absorption observed prior to crystal formation is in part caused by an increase NHE activity which is not fully accounted for by an increase in NHE proteins and mRNA levels but may be explained by enhanced localization in the membranes and/or altered regulation of NHE.

Determination of volatile organic compounds in river water by solid phase extraction and gas chromatography.

A simple, rapid, and reproducible method is described employing solid-phase extraction (SPE) using dichloromethane followed by gas chromatography (GC) with flame ionization detection (FID) for determination of volatile organic compound (VOC) from the Buriganga River water of Bangladesh. The method was applied to detect the benzene, toluene, ethylbenzene, xylene and cumene (BTEXC) in the sample collected from the surface or 15 cm depth of water. Two-hundred ml of n-hexane-pretreated and filtered water samples were applied directly to a C18 SPE column. BTEXC were extracted with dichloromethane and average concentrations were obtained as 0.104 to 0.372 microg/ml. The highest concentration of benzene was found as 0.372 microg/ml with a relative standard deviation (RSD) of 6.2%, and cumene was not detected. Factors influencing SPE e.g., adsorbent types, sample load volume, eluting solvent, headspace and temperatures, were investigated. A cartridge containing a C18 adsorbent and using dichloromethane gave better performance for extraction of BTEXC from water. Average recoveries exceeding 90% could be achieved for cumene at 4 degrees C with a 2.7% RSD.

Functional characterization of Na(+)/H(+) exchangers in primary cultures of prairie dog gallbladder.

Gallbladder Na(+) absorption is linked to gallstone formation in prairie dogs. We previously reported Na(+)/H(+) exchanger (NHE1-3) expression in native gallbladder tissues. Here we report the functional characterization of NHE1, NHE2 and NHE3 in primary cultures of prairie dog gallbladder epithelial cells (GBECs). Immunohistochemical studies showed that GBECs grown to confluency are homogeneous epithelial cells of gastrointestinal origin. Electron microscopic analysis of GBECs demonstrated that the cells form polarized monolayers characterized by tight junctions and apical microvilli. GBECs grown on Snapwells exhibited polarity and developed transepithelial short-circuit current, I(sc), (11.6 +/- 0.5 microA. cm(-2)), potential differences, V(t) (2.1 +/- 0.2 mV), and resistance, R(t) (169 +/- 12 omega. cm(2)). NHE activity in GBECs assessed by measuring dimethylamiloride-inhibitable (22)Na(+) uptake under a H(+) gradient was the same whether grown on permeable Snapwells or plastic wells. The basal rate of (22)Na(+) uptake was 21.4 +/- 1.3 nmol x mg prot(-1) x min(-1), of which 9.5 +/- 0.7 (approximately 45%) was mediated through apically-restricted NHE. Selective inhibition with HOE-694 revealed that NHE1, NHE2 and NHE3 accounted for approximately 6%, approximately 66% and approximately 28% of GBECs' total NHE activity, respectively. GBECs exhibited saturable NHE kinetics ( V(max) 9.2 +/- 0.3 nmol x mg prot(-1) x min(-1); K(m) 11.4 +/- 1.4 m M Na(+)). Expression of NHE1, NHE2 and NHE3 mRNAs was confirmed by RT-PCR analysis. These results demonstrate that the primary cultures of GBECs exhibit Na(+) transport characteristics similar to native gallbladder tissues, suggesting that these cells can be used as a tool for studying the mechanisms of gallbladder ion transport both under physiologic conditions and during gallstone formation.