Seeking excellence: An evaluation of 235 international laboratories conducting water isotope analyses by isotope-ratio and laser-absorption spectrometry.

RATIONALE: Water stable isotope ratios (δ2 H and δ18 O values) are widely used tracers in environmental studies; hence, accurate and precise assays are required for providing sound scientific information. We tested the analytical performance of 235 international laboratories conducting water isotope analyses using dual-inlet and continuous-flow isotope ratio mass spectrometers and laser spectrometers through a water isotope inter-comparison test. METHODS: Eight test water samples were distributed by the IAEA to international stable isotope laboratories. These consisted of a core set of five samples spanning the common δ-range of natural waters, and three optional samples (highly depleted, enriched, and saline). The fifth core sample contained unrevealed trace methanol to assess analyst vigilance to the impact of organic contamination on water isotopic measurements made by all instrument technologies. RESULTS: For the core and optional samples ~73 % of laboratories gave acceptable results within 0.2 ‰ and 1.5 ‰ of the reference values for δ18 O and δ2 H, respectively; ~27 % produced unacceptable results. Top performance for δ18 O values was dominated by dual-inlet IRMS laboratories; top performance for δ2 H values was led by laser spectrometer laboratories. Continuous-flow instruments yielded comparatively intermediate results. Trace methanol contamination of water resulted in extreme outlier δ-values for laser instruments, but also affected reactor-based continuous-flow IRMS systems; however, dual-inlet IRMS δ-values were unaffected. CONCLUSIONS: Analysis of the laboratory results and their metadata suggested inaccurate or imprecise performance stemmed mainly from skill- and knowledge-based errors including: calculation mistakes, inappropriate or compromised laboratory calibration standards, poorly performing instrumentation, lack of vigilance to contamination, or inattention to unreasonable isotopic outcomes. To counteract common errors, we recommend that laboratories include 1-2 'known' control standards in all autoruns; laser laboratories should screen each autorun for spectral contamination; and all laboratories should evaluate whether derived d-excess values are realistic when both isotope ratios are measured. Combined, these data evaluation strategies should immediately inform the laboratory about fundamental mistakes or compromised samples.

Measurement of extremely (2) H-enriched water samples by laser spectrometry: application to batch electrolytic concentration of environmental tritium samples.

RATIONALE: Natural water samples artificially or experimentally enriched in deuterium ((2) H) at concentrations up to 10,000 ppm are required for various medical, environmental and hydrological tracer applications, but are difficult to measure using conventional stable isotope ratio mass spectrometry. METHODS: Here we demonstrate that off-axis integrated cavity output (OA-ICOS) laser spectrometry, along with (2) H-enriched laboratory calibration standards and appropriate analysis templates, allows for low-cost, fast, and accurate determinations of water samples having δ(2) HVSMOW-SLAP values up to at least 57,000 ‰ (~9000 ppm) at a processing rate of 60 samples per day. RESULTS: As one practical application, extremely (2) H-enriched samples were measured by laser spectrometry and compared to the traditional (3) H Spike-Proxy method in order to determine tritium enrichment factors in the batch electrolysis of environmental waters. Highly (2) H-enriched samples were taken from different sets of electrolytically concentrated standards and low-level (<10 TU) IAEA inter-comparison tritium samples, and all cases returned accurate and precise initial low-level (3) H results. CONCLUSIONS: The ability to quickly and accurately measure extremely (2) H-enriched waters by laser spectrometry will facilitate the use of deuterium as a tracer in numerous environmental and other applications. For low-level tritium operations, this new analytical ability facilitated a 10-20 % increase in sample productivity through the elimination of spike standards and gravimetrics, and provides immediate feedback on electrolytic enrichment cell performance. Copyright © 2016 John Wiley & Sons, Ltd.

Noninvasive assessment of bone health in Indian patients with chronic kidney disease.

Abnormalities in mineral and bone disease are common in chronic kidney disease (CKD). Evaluation of bone health requires measurement of parameters of bone turnover, mineralization, and volume. There are no data on bone health in CKD patients from India. In this cross-sectional study, we evaluated serum biomarkers of bone turnover: Bone-specific alkaline phosphatase (BAP) and total deoxypyridinoline (tDPD) along with parathyroid hormone, 25(OH) vitamin D, and bone mineral density (BMD) using dual absorption X-ray absorptiometry in a cohort of 74 treatment-naive patients with newly diagnosed stage 4 and 5 CKD (age 42 ± 14.5 years, 54 men) and 52 non-CKD volunteers (age 40.2 ± 9.3 years, 40 men). Compared to the controls, CKD subjects showed elevated intact PTH (iPTH), BAP, and tDPD and lower BMD. There was a strong correlation between iPTH and BAP (r = 0.88, P < 0.0001), iPTH and tDPD (r = 0.51, P < 0.0001), and BAP and tDPD (r = 0.46, P = 0.0004). The iPTH elevation was greater than twice the upper range of normal in 73% cases, and BAP was >40 U/L in 66% cases. The combination of these markers suggests high turnover bone disease in over 60% cases. The prevalence of osteopenia and osteoporosis was 37% and 12%, respectively. Osteoporotic subjects had higher iPTH, BAP, and tDPD, suggesting a role of high turnover in genesis of osteoporosis. Vitamin D deficiency was seen in 80%, and another 13% had insufficient levels. Vitamin D correlated inversely with BAP (r = -0.3, P = 0.009), and levels were lower in those with iPTH >300 pg/ml (P = 0.0.04). In conclusion, over 60% of newly diagnosed Indian stage 4-5 CKD patients show biochemical parameters consistent with high turnover bone disease. High turnover could contribute to the development of osteoporosis in CKD subjects. Deficiency of 25 (OH) vitamin D is widespread and seems to have a role in the genesis of renal bone disease. Studies on the effect of supplementation of native vitamin D are needed.

Pulmonary coccidiomycosis in New Delhi, India.

Coccidioidomycosis is an endemic disease of the western hemisphere. In cases occurring in non-endemic areas, eliciting a history of exposure as well as a high index of suspicion is imperative for timely and accurate diagnosis. In this case, a 65-year-old male presented to our hospital with fever, dry cough and malaise, and on X-ray chest, was found to have a lower lobe consolidation left lung with nodular lesions in both lungs and necrotic mediastinal lymphadenopathy. He lived in Arizona, USA, for 6 months before admission. Pulmonary coccidioidomycosis was confirmed by the isolation of Coccidioides spp. in pure culture from both broncho-alveolar lavage and lung biopsy specimens. The identity of the isolate was confirmed as C. posadasii by gene sequencing. The patient improved after being treated with fluconazole.

The relationship between circulating endothelin-1, soluble fms-like tyrosine kinase-1 and soluble endoglin in preeclampsia.

Placental overproduction of anti-angiogenic soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng) has a key role in the development of preeclampsia (PE). Circulating endothelin-1 (ET-1) levels are also elevated in PE. In this study, we investigated the correlation between ET-1 and sFlt-1, placental growth factor (PlGF), sEng levels during uncomplicated normotensive pregnancy and PE. A total of 218 pregnant primigravid women were enrolled: 110 with PE and 108 uncomplicated normotensive pregnancies. PE was defined as new onset of elevated blood pressure (BP) >140/90 mm Hg and ≥2+ proteinuria on two occasions after 20 weeks of gestation in previously normotensive pregnant women. Circulating ET-1, sFlt-1, sEng and PlGF levels were estimated using enzyme immunoassays, and correlation between variables was ascertained. Women with PE showed higher levels of sFlt-1 (41.5±15.7 vs 6.15±3.4 ng ml(-1), P<0.001), sEng (84.9±38.8 vs 13.2±6.3 ng ml(-1), P<0.001), ET-1 (1.52±0.55 vs 0.88±0.35 pg ml(-1), P<0.001) and sFlt-1:PlGF ratio (591.1±468.4 vs 18.3±2.1, P<0.001); and lower levels of PlGF (96.3±47.2 vs 497.6±328.2 pg ml(-1), P<0.001). BP levels showed an independent relationship with sFlt-1:PlGF ratio in normotensive pregnant women and with sFlt-1:PlGF ratio and ET-1 in PE. sFlt-1 and sFlt-1:PlGF ratio correlated with proteinuria. ET-1 correlated significantly with sFlt-1, sEng and sFlt-1:PlGF ratio in PE. Our results show an association between elevation of sFlt-1 and sEng and ET-1 in the maternal circulation in PE, and strengthen the possibility that ET-1 may be a mediator in genesis of PE syndrome secondary to anti-angiogenic factors released by the placenta.

Anticarcinogenic effect of probiotic fermented milk and chlorophyllin on aflatoxin-B1-induced liver carcinogenesis in rats.

The present investigation was carried out to evaluate the hepatoprotective effect of probiotic fermented milk (FM) containing Lactobacillus rhamnosus GG and Lactobacillus casei strain Shirota, alone as well as in combination with chlorophyllin (CHL) as an antioxidant agent in male Wistar rats administered aflatoxin-B1 (AFB1). AFB1 was injected intraperitoneally at the rate of 450 µg/kg body weight per animal twice a week for 6 weeks, maintaining an equal time interval between the two consecutive AFB1 administrations. A total of 125 male Wistar rats were randomly allocated to five groups, each group having twenty-five animals. Group I was offered FM containing L. rhamnosus GG and L. casei strain Shirota. Group II was administered AFB1 and served as the control group; group III was administered FM-AFB1, in which besides administering AFB1, FM was also offered. Group IV was offered CHL and AFB1, and group V was offered both FM and CHL along with AFB1. The rats were euthanised at the 15th and 25th week of the experiment and examined for the biochemical and hepatopathological profile. A significant reduction in thiobarbituric acid-reactive substances (TBARS) was observed in the FM-CHL-AFB1 group compared with the AFB1 control group. FM alone or in combination with CHL was found to show a significant (P < 0·05) hepatoprotective effect by lowering the levels of TBARS and by enhancing the activities of antioxidant enzymes such as glutathione peroxidase, superoxide dismutase, catalase and glutathione-S-transferase, indicating that probiotic FM alone or in combination with CHL possesses a potent protective effect against AFB1-induced hepatic damage.

Iron status, inflammation and hepcidin in ESRD patients: The confounding role of intravenous iron therapy.

Uremia is a state of heightened inflammatory activation. This might have an impact on several parameters including anemia management. Inflammation interferes with iron utilization in chronic kidney disease through hepcidin. We studied the body iron stores, degree of inflammatory activation, and pro-hepcidin levels in newly diagnosed patients with end-stage renal disease (ESRD), and compared them with normal population. In addition to clinical examination and anthropometry, the levels of iron, ferritin, C-reactive protein, tumor necrosis factor alfa, interleukin-6, and prohepcidin were estimated. A total of 74 ESRD patients and 52 healthy controls were studied. The ESRD patients had a significantly lower estimated body fat percentage, muscle mass, and albumin; and higher transferrin saturation (TSAT) and raised serum ferritin. Inflammatory activation was evident in the ESRD group as shown by the significantly higher CRP, IL-6, and TNF-α levels. The pro-hepcidin levels were also increased in this group. Half of the ESRD patients had received parenteral iron before referral. Patients who had received intravenous iron showed higher iron, ferritin, and TSAT levels. These patients also showed more marked inflammatory activation, as shown by the significantly higher CRP, TNF-α, and IL-6 levels. We conclude that our ESRD patients showed marked inflammatory activation, which was more pronounced in patients who had received IV iron. High hepcidin levels could explain the functional iron deficiency. The cause of the relatively greater degree of inflammatory activation as well as the relationship with IV iron administration needs further studies.

Cancer-preventing attributes of probiotics: an update.

Cancer is a serious global public health problem. Cancer incidence and mortality have been steadily rising throughout the past century in most places of the world. There are several epidemiological evidences that support a protective role of probiotics against cancer. Lactic acid bacteria and their probioactive cellular substances exert many beneficial effects in the gastrointestinal tract, and also release various enzymes into the intestinal lumen and exert potential synergistic (LAB) effects on digestion and alleviate symptoms of intestinal malabsorption. Consumption of fermented dairy products with LAB may elicit anti-tumor effects. These effects are attributed to the inhibition of mutagenic activity, the decrease in several enzymes implicated in the generation of carcinogens, mutagens, or tumor-promoting agents, suppression of tumors, and epidemiology correlating dietary regimes and cancer. Specific cellular components in lactic acid bacteria seem to induce strong adjuvant effects including modulation of cell-mediated immune responses, activation of the reticulo-endothelial system, augmentation of cytokine pathways, and regulation of interleukins and tumor necrosis factors. Studies on the effect of probiotic consumption on cancer appear promising, since recent in vitro and in vivo studies have indicated that probiotic bacteria might reduce the risk, incidence and number of tumors of the colon, liver and bladder. The protective effect against cancer development may be ascribed to binding of mutagens by intestinal bacteria, may suppress the growth of bacteria that convert procarcinogens into carcinogens, thereby reducing the amount of carcinogens in the intestine, reduction of the enzymes beta-glucuronidase and beta-glucosidase and deconjugation of bile acids, or merely by enhancing the immune system of the host. There are isolated reports citing that administration of LAB results in increased activity of anti-oxidative enzymes or by modulating circulatory oxidative stress that protects cells against carcinogen-induced damage. These include glutathione-S-transferase, glutathione, glutathione reductase, glutathione peroxidase, superoxide dismutase and catalase. However, there is no direct experimental evidence for cancer suppression in human subjects as a result of the consumption of probiotic cultures in fermented or unfermented dairy products, but there is a wealth of indirect evidence based largely on laboratory studies.

Simulating coconut growth, development and yield with the InfoCrop-coconut model.

Simulation modeling of perennial crops has immense potential for generating information for plantation managers. We report the development of the InfoCrop-coconut model and its application to coconut (Cocos nucifera L.) growing in diverse tropical and subtropical environments. The model is based on the generic crop model InfoCrop that simulates various annual crops in tropical and subtropical regions. The InfoCrop-coconut model was calibrated and validated with data compiled from published studies comprising many physiological, agronomical and nutritional experiments conducted between 1978 and 2005 in diverse geographic locations throughout India. The treatments included various water and nutrient regimes and varieties of coconut. Time to first flowering varied between 4 and 6 years, leaf production varied from 8 to 15 leaves year(-1) and nut yield ranged from 3000 to 27,000 nuts ha(-1) year(-1). The genetic coefficients used for calibration and validation were generated from field experiments conducted during 1995-2005. Model efficiency and validation performance were analyzed statistically. Simulated trends in phenological development, total dry mass and its partitioning, and nut yield agreed closely with observed values, although a 15% error was observed in a few cases. Considering that field measurements have an experimental error of 10-15% and wide variation existed within treatments, the model adequately simulated the effects of management practices and agro-climatic conditions over short periods. For a range of agro-climatic zones, simulated potential yields varied from 26 to 30 Mg ha(-1) year(-1) and potential annual dry mass production varied from 52 to 62 Mg ha(-1), depending on environment. We conclude that InfoCrop-coconut can be used to increase the efficiency of agronomic experiments designed to aid coconut crop management.

Purification and characterization of Enterobacter sakazakii enterotoxin.

Enterobacter sakazakii has recently been recognized as an often fatal neonatal pathogen that rarely infects adults. Although not much is known about factors involved in its pathogenicity, the organism has been reported to produce enterotoxin. Currently, no information is available in the literature about the production and characterization of the enterotoxin. This report is the first attempt regarding purification and biochemical characterization of the enterotoxin produced from E. sakazakii. The toxin was purified by ammonium sulfate precipitation, followed by DEAE cellulose ion exchange and desalting by Sephadex G-100. The 66 kDa toxin was most active at pH 6 and was stable at 90 degrees C for 30 min. This stability combined with the potent activity of the toxin (LD50 = 56 pg) emphasizes the potential risk to neonates fed infant milk formula contaminated with E. sakazakii. Further detailed molecular biological studies on the toxin are warranted in view of its stability and activity.

Quantifying submarine groundwater discharge in the coastal zone via multiple methods.

Submarine groundwater discharge (SGD) is now recognized as an important pathway between land and sea. As such, this flow may contribute to the biogeochemical and other marine budgets of near-shore waters. These discharges typically display significant spatial and temporal variability making assessments difficult. Groundwater seepage is patchy, diffuse, temporally variable, and may involve multiple aquifers. Thus, the measurement of its magnitude and associated chemical fluxes is a challenging enterprise. A joint project of UNESCO and the International Atomic Energy Agency (IAEA) has examined several methods of SGD assessment and carried out a series of five intercomparison experiments in different hydrogeologic environments (coastal plain, karst, glacial till, fractured crystalline rock, and volcanic terrains). This report reviews the scientific and management significance of SGD, measurement approaches, and the results of the intercomparison experiments. We conclude that while the process is essentially ubiquitous in coastal areas, the assessment of its magnitude at any one location is subject to enough variability that measurements should be made by a variety of techniques and over large enough spatial and temporal scales to capture the majority of these changing conditions. We feel that all the measurement techniques described here are valid although they each have their own advantages and disadvantages. It is recommended that multiple approaches be applied whenever possible. In addition, a continuing effort is required in order to capture long-period tidal fluctuations, storm effects, and seasonal variations.

Characterisation of submarine groundwater discharge offshore south-eastern Sicily.

A complex approach in characterisation of submarine groundwater discharge (SGD) off south-eastern Sicily comprising applications of radioactive and non-radioactive tracers, direct seepage measurements, geophysical surveys and a numerical modelling is presented. SGD fluxes in the Donnalucata boat basin were estimated by direct seepage measurements to be from 4 to 12Ls(-1), which are comparable with the total SGD flux in the basin of 17Ls(-1) obtained from radon measurements. The integrated SGD flux over the Donnalucata coast estimated on the basis of Ra isotopes was around 60m(3)s(-1) per km of the coast. Spatial variations of SGD were observed in the Donnalucata boat basin, the average (222)Rn activity concentration in seawater varied from approximately 0.1kBqm(-3) to 3.7kBqm(-3) showing an inverse relationship with salinity. The continuous monitoring carried out at the site closest to the coast has revealed an inverse relationship of (222)Rn activity concentration on the tide. The (222)Rn concentrations in seawater varied from 2.3kBqm(-3) during high tides to 4.8kBqm(-3) during low tides, thus confirming an influence of the tide on submarine groundwater discharge. Stable isotopes (delta(2)H and delta(18)O) showed that SGD samples consist up to 50% of groundwater. Geo-electrical measurements showed a spatial variability of the salt/fresh water interface and its complex transformation in the coastal zone. The presented results imply that in the studied Donnalucata site there are at least two different sources of SGD, one superficial, represented by mixed fresh water and seawater, and the second one which originates in a deeper limestone aquifer.

Dynamics of organic carbon and microbial biomass in alluvial soil with tillage and amendments in rice-wheat systems.

Rice-wheat cropping systems of the Indo-Gangetic plains (IGP) occupying 12 million ha of productive land are important for the food security of South Asia. There are, however, concerns that yield and factor productivity trends in these systems are declining/stagnating in recent years. Decrease in soil organic carbon is often suggested as a reason for such trends. A field experiment was conducted to study the soil organic carbon (SOC) and soil microbial biomass carbon (MBC) dynamics in the rice-wheat systems. Use of organic amendments and puddling of soil before rice transplanting increased SOC and MBC contents. Microbial biomass carbon showed a seasonal pattern. It was low initially, reached its peak during the flowering stages in both rice and wheat and declined thereafter. Microbial biomass carbon was linearly related to SOC in both rice and wheat indicating that SOC could be used as a proxy for MBC.

Low urinary placental growth factor is a marker of pre-eclampsia.

Recent reports of increased serum levels of soluble fms-like tyrosine kinase 1 (sFlt-1) and decreased levels of placental growth factor (PlGF) suggest the key role of angiogenic factors in development of pre-eclampsia. PlGF is excreted in urine, and reduced urinary level has been suggested as a marker of this condition as well as help in its prediction. We measured urinary PlGF and creatinine values in 69 pregnant women (35 with pre-eclampsia and 34 normotensive controls). Over 70% patients had severe pre-eclampsia. Compared to controls, the urinary PlGF and PlGF/creatinine levels were significantly reduced in women with pre-eclampsia. The hospital stay was longer and fetal outcomes poorer in this group. Three normotensive women who showed very low levels developed pre-eclampsia 2-6 weeks later. Reduced urinary PlGF level in a pregnant woman is a marker of pre-eclampsia. The value of reduced urinary PlGF levels in predicting pre-eclampsia in currently normotensive pregnant women needs to be evaluated. A simple predictive test is likely to be of value in the developing countries.

Extrapleural anterolateral decompression in tuberculosis of the dorsal spine.

We reviewed 64 anterolateral decompressions performed on 63 patients with tuberculosis of the dorsal spine (D1 to L1). The mean age of the patients was 35 years (9 to 73) with no gender preponderance. All patients had severe paraplegia (two cases grade III, 61 cases grade IV). The mean number of vertebral bodies affected was 2.6; the mean pre-treatment kyphosis was 24.8 degrees (7 to 84). An average of 2.9 ribs were removed in the course of 64 procedures. The mean time taken at surgery was 2.45 hours when two ribs were removed and 3.15 hours when three ribs were removed. Twelve patients (19%) showed signs of neurological recovery within seven days, 33 patients (52%) within one month and 12 patients (19%) after two months; but six patients (10%) showed no neurological recovery. Forty patients were followed up for more than two years. In 34 (85%) of these patients there was no significant change in the kyphotic deformity; two patients (5%) showed an increase of more than 20 degrees.

Behaviour of the kyphotic angle in spinal tuberculosis.

We followed 70 adult patients with spinal tuberculosis for a minimum of 2 years. Forty patients were treated by ambulant multi-drug chemotherapy (group A), and 30 with neurological complications (group B) were treated by antero-lateral decompression and chemotherapy. We studied the angle of spinal kyphosis as calculated on lateral spinal X-ray by the modified Konstam's method. The angle at final follow-up was compared with the pre-treatment angle. The relationship between the amount of initial vertebral loss, the predicted kyphotic angle and the observed kyphotic angle was analysed. Mean initial vertebral loss, mean pre-treatment angle and mean observed kyphotic angle in group A were 0.77 degrees, 24.3 degrees and 31.75 degrees respectively, with a mean increase in angle of 7.4 degrees. In group B, the readings were 0.67, 25.9 degrees and 26.8 degrees respectively, with a mean increase in angle of 0.9 degrees. Kyphotic deformity continued to progress until 2 years' follow-up. Progression was more pronounced in the non-operative group.

Salmonella osteomyelitis in an otherwise healthy adult male-successful management with conservative treatment: a case report.

A 21-year-old male presented with pain in the right thigh of insidious onset and 3 months' duration. He had a history of febrile illness lasting for 15 days, 2 months prior to the onset of pain. Examination revealed swelling over the lower lateral aspect of the right thigh with some induration and tenderness. Initial X-rays of the right femur and the computed tomography scan at 10 weeks after the onset of disease were normal. Magnetic resonance imaging scan showed signal alteration with minimal destruction of the anterior cortex in the mid-diaphyseal region of the right femur. A repeated X-ray taken at 15 weeks after the onset of illness showed erosive changes, along with periosteal reaction in the diaphyseal area. The Widal test was positive. Open biopsy of the lesion revealed inflammatory non-caseating tissue. Culture of the specimen grew Salmonella typhi. The patient was given antibiotic treatment. Both X-rays and the Widal titres were normal on subsequent follow-up at 3 months.

Hodgkin's disease and scleroderma.

We report here the uncommon association between scleroderma and Hodgkin's disease in a 42 years male.