Mixed-power scaling of whole-plant respiration from seedlings to giant trees.

The scaling of respiratory metabolism with body mass is one of the most pervasive phenomena in biology. Using a single allometric equation to characterize empirical scaling relationships and to evaluate alternative hypotheses about mechanisms has been controversial. We developed a method to directly measure respiration of 271 whole plants, spanning nine orders of magnitude in body mass, from small seedlings to large trees, and from tropical to boreal ecosystems. Our measurements include the roots, which have often been ignored. Rather than a single power-law relationship, our data are fit by a biphasic, mixed-power function. The allometric exponent varies continuously from 1 in the smallest plants to 3/4 in larger saplings and trees. Therefore, our findings support the recent findings of Reich et al. [Reich PB, Tjoelker MG, Machado JL, Oleksyn J (2006) Universal scaling of respiratory metabolism, size, and nitrogen in plants. Nature 439:457-461] and West, Brown, and Enquist [West GB, Brown JH, Enquist BJ (1997) A general model for the origin of allometric scaling laws in biology. Science 276:122 -126.]. The transition from linear to 3/4-power scaling may indicate fundamental physical and physiological constraints on the allocation of plant biomass between photosynthetic and nonphotosynthetic organs over the course of ontogenetic plant growth.

Predicting Difficult Intubation by using Modified Mallampati (MMT) with or without Thyromental Height Test (TMHT).

Failed Tracheal Intubation with Subsequent inability to maintain an open airway and adequate oxygenation is the most frequent cause of brain damage or death during anesthesia. Recognizing before anesthesia the potential for difficult intubation allows time for optimal preparation. Proper Selection of equipment and techniques is needed to avoid unwanted situation. To find out difficulties associated with endotracheal intubation using Modified Mallampati Test (MMT) combined with Thyromental Height Test (TMHT) and MMT without TMHT. This prospective observational study was conducted at the Department of Anesthesia in Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from April 2018 to September 2018. Two hundred two patients with different surgical procedures under general anaesthesia in different operation theaters of BSMMU, Dhaka were selected as study population. After taking written consents from each patient or his/her attendant elaborate history of illness, meticulous clinical examinations were performed and relevant laboratory investigations were done. All information was recorded in a preformed data sheet and statistical analysis was done by SPSS-22.0. Mean age ±SD of the study subjects was 42.49±14.29 years in MMT with TMHT group and 43.40±15.39 years in MMT without TMHT group. Females were enrolled more than males in both the groups. BMI was 28.75±3.59kg/m² in MMT with TMHT group and 29.44±8.64kg/m² in MMT without TMHT group. There were no significant differences in age, gender and BMI between the groups. Sensitivity, specificity, PPV, NPV and accuracy were 100.0%, 96.0%, 96.2%, 100.0% and 98.0% respectively of MMT with TMHT in predicting intubation difficulty. Sensitivity, specificity, PPV, NPV and accuracy were 100.0%, 96.0%, 96.2%, 100.0% and 98.0% respectively of MMT only in predicting intubation difficulty. MMT combined with TMHT is a better predictor of intubation difficulty than MMT alone.

Emergence of multidrug-resistant NDM-1-producing Gram-negative bacteria in Bangladesh.

The main objective of this study was to investigate the prevalence of bla (NDM-1) in Gram-negative bacteria in Bangladesh. In October 2010 at the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B) laboratories, 1,816 consecutive clinical samples were tested for imipenem-resistant Gram-negative organisms. Imipenem-resistant isolates were tested for the bla (NDM-1) gene. Among 403 isolates, 14 (3.5 %) were positive for bla (NDM-1), and the predominant species were Klebsiella pneumoniae, Acinetobacter baumannii, and Escherichia coli. All bla (NDM-1)-positive isolates were resistant to multiple antibiotics. Among ß-lactamase genes, bla (CTX-M-1-group) was detected in ten isolates (eight bla (CTX-M-15)), bla (OXA-1-group) in six, bla (TEM) in nine, bla (SHV) in seven, and bla (VIM) and bla (CMY) in two isolates each. The 16S rRNA methylase gene, armA, was detected in five K. pneumoniae isolates and in one E. coli isolate. rmtB and rmtC were detected in a Citrobacter freundii and two K. pneumoniae isolates, respectively. qnr genes were detected in two K. pneumoniae isolates (one qnrB and one qnrS) and in an E. coli isolate (qnrA). Transferable plasmids (60-100 MDa) carrying bla (NDM-1) were detected in 7 of the 11 plasmid-containing isolates. Pulsed-field gel electrophoresis (PFGE) analysis grouped K. pneumoniae isolates into three clusters, while E. coli isolates differed significantly from each other. This study reports that approximately 3.5 % of Gram-negative clinical isolates in Bangladesh are NDM-1-producing.

Bacterial aetiology of diarrhoeal diseases and antimicrobial resistance in Dhaka, Bangladesh, 2005-2008.

Infectious diarrhoea caused by bacterial pathogens contributes to the high level of mortality in developing countries like Bangladesh. Following standard bacteriological procedures, a total of 14 428 bacterial pathogens were isolated from 56 132 stool samples and rectal swabs collected from diarrhoeal patients between 2005 and 2008. The rate of isolation and antimicrobial susceptibility data were retrospectively analysed for these isolates and among them Vibrio spp. (42·9%) were the most predominant, followed by Shigella spp. (20·3%), Aeromonas spp. (12·8%) and Salmonella spp. (6·4%). A decreasing trend in isolation of Vibrio spp. (P<0·001) and Salmonella spp. (P<0·001) was observed. While Vibrio cholerae isolates remained susceptible to ciprofloxacin, an increase in resistance was observed in Campylobacter spp. and Shigella flexneri. Variations in susceptibility to other tested antibiotics were observed among the isolated pathogens. Access to this current data will help in understanding the local burden of diarrhoeal disease and contribute to better design of prevention programmes.

Progression of anaemia during antenatal period among South African pregnant women.

Background: Anaemia in pregnancy is a known public health problem in South Africa. Maternal, perinatal morbidity and mortality are known to be associated with anaemia in pregnancy. Very little is known from literature with regards to the progression of anaemia during the antenatal period of pregnancy. Objectives: To estimate haemoglobin levels, the prevalence and determinants of anaemia at different gestational ages and to show the trend. Method: A retrospective cohort (follow-up) study was conducted using the antenatal clinic register. Prevalence rates of anaemia (haemoglobin < 11 g/dl) at different gestational ages were measured. Factors associated with anaemia were assessed using chi-square test and stepwise multivariate logistic regression analysis. Results: A total of 801 pregnant women were enrolled at the booking visit and followed-up during their antenatal period. The prevalence of anaemia at the booking visit was 37%. The prevalence of anaemia at 20, 26, 32 and 36 weeks of gestation were 36.6%, 39.6%, 39.8% and 29.2% respectively. Binary logistic regression at the booking visit showed that teenage women were 2.5 times more likely to have anaemia (OR=2.5, p=0.005) than older women. Women who booked during the first trimester were 60% less likely to have anaemia (OR= 0.40, P=0.005) at the booking visit and 62% less likely to be anaemic at 36 weeks of gestation (OR=0.38, p=0.013) compared to those who booked late for antenatal care. Conclusion: Prevalence of anaemia during pregnancy was high. Early booking for antenatal care was a predictor for lower rate of anaemia. Thus, health education strategy should be encouraged for early antenatal booking.

A Comprehensive Survey on the Progress, Process, and Challenges of Lung Cancer Detection and Classification.

Lung cancer is the primary reason of cancer deaths worldwide, and the percentage of death rate is increasing step by step. There are chances of recovering from lung cancer by detecting it early. In any case, because the number of radiologists is limited and they have been working overtime, the increase in image data makes it hard for them to evaluate the images accurately. As a result, many researchers have come up with automated ways to predict the growth of cancer cells using medical imaging methods in a quick and accurate way. Previously, a lot of work was done on computer-aided detection (CADe) and computer-aided diagnosis (CADx) in computed tomography (CT) scan, magnetic resonance imaging (MRI), and X-ray with the goal of effective detection and segmentation of pulmonary nodule, as well as classifying nodules as malignant or benign. But still, no complete comprehensive review that includes all aspects of lung cancer has been done. In this paper, every aspect of lung cancer is discussed in detail, including datasets, image preprocessing, segmentation methods, optimal feature extraction and selection methods, evaluation measurement matrices, and classifiers. Finally, the study looks into several lung cancer-related issues with possible solutions.

Prevalence of stroke above forty years.

Number of elderly persons gradually increased in Bangladesh due to improved health awareness and health care. Age is the single most important risk factor for stroke. This study aims at finding the prevalence of stroke in a Bangladeshi population aged forty years and above. The cases of stroke were ascertained in two phases of door-to-door survey. In phase-I, trained interviewers performed face-to-face interview with subjects for the detection stroke cases using the World Health Organization (WHO) screening protocol for neurological diseases. In phase-II, subjects suspected to have a stroke underwent a clinical evaluation for diagnosis or exclusion of stroke by a neurological team. The study involved 15627 participants aged 40 years and above. A total of 47 participants found to have stroke, expressing an overall prevalence rate of 3.00 per 1000 (95% CI 0.95 to 2.45). Prevalence of stroke were 2.0, 3.0, 2.0, 10.0, and 10.0 per 1000 within age groups of 40-49 years, 50-59 years, 60-69 years, 70-79 years and 80 years and above age group respectively. Prevalence of stroke in people with age range 70-79 years compared to 40-49 years age range is 4.988 (95% CI 2.309 to 10.77) times and people with age range ≥80 years compared to 40-49 years age range is 4.798 (95% CI 1.597 to14.416) times. Prevalence was higher among men in comparison with women. The male: female ratio is 3.44:2.41 per 1000 respectively. Bangladeshi male populations in rural areas are found to have stroke more than urban people. A large community based study should be undertaken to further confirm the result of this present study.

Kinematic Measurements of Novel Chaotic Micromixers to Enhance Mixing Performances at Low Reynolds Numbers: Comparative Study.

In this work, a comparative investigation of chaotic flow behavior inside multi-layer crossing channels was numerically carried out to select suitable micromixers. New micromixers were proposed and compared with an efficient passive mixer called a Two-Layer Crossing Channel Micromixer (TLCCM), which was investigated recently. The computational evaluation was a concern to the mixing enhancement and kinematic measurements, such as vorticity, deformation, stretching, and folding rates for various low Reynolds number regimes. The 3D continuity, momentum, and species transport equations were solved by a Fluent ANSYS CFD code. For various cases of fluid regimes (0.1 to 25 values of Reynolds number), the new configuration displayed a mixing enhancement of 40%-60% relative to that obtained in the older TLCCM in terms of kinematic measurement, which was studied recently. The results revealed that all proposed micromixers have a strong secondary flow, which significantly enhances the fluid kinematic performances at low Reynolds numbers. The visualization of mass fraction and path-lines presents that the TLCCM configuration is inefficient at low Reynolds numbers, while the new designs exhibit rapid mixing with lower pressure losses. Thus, it can be used to enhance the homogenization in several microfluidic systems.

Identification of citrus greening based on visual symptoms: A grower's diagnostic toolkit.

Citrus greening is one of the world's most serious diseases of citrus that affects all cultivars and causes the systematic death of trees worldwide. The disease is caused mostly by the bacteria Candidatus Liberibacter species. The wind, rain, and touch of infected workers cannot transmit this infectious disease. The Asian Citrus Psyllid (ACP), a minuscule insect, is one of the main vectors that transmit the disease by feeding on citrus leaves. Citrus greening management is also quite expensive since no successful treatment for the cure has been found, except to remove all affected vegetables from healthy crops to eliminate the bacterial spread. Citrus greening is also the most challenging task, as signs of other citrus diseases and nutritional deficiencies are identical. The major signs of this disease are asymmetrical, blotchy mottling patterns on leaves. Here, several visible indications of citrus greening were addressed, which will enable farmers at the root level to detect and avoid this condition prior to its having a dramatic influence on citrus plantations. We also talked about the pen test method to determine symptoms as symmetrical or asymmetrical throughout the mid-vine, regardless of whether they are impacted by citrus greening or lack of nutrients.

Epilepsy and abnormal electroencephalogram in children with autism spectrum disorder.

Epilepsy occurs in 30 to 40% of individuals with autism spectrum disorder (ASD). However the association of epilepsy or abnormal electroencephalogram is not known in our population. This study addresses the incidence of epilepsy and or abnormal electroencephalogram in Bangladeshi children with autism spectrum disorder. The clinical history and electroencephalogram of 18 children diagnosed with autism spectrum disorder were retrospectively reviewed. Forty four percent were diagnosed with epilepsy or abnormal electroencephalogram. This abnormal electroencephalogram or epilepsy occurred at significantly higher rates in children with more impaired range of autism spectrum disorder. These finding suggest that the use of neurological investigative technique such as electroencephalogram (EEG) should be considered routinely in children with autism spectrum disorder especially in more impaired individuals.

Correlation of Mean Platelet Volume with ST Segment Resolution after Thrombolytic Therapy in Patients with ST Elevation Myocardial Infarction.

Acute occlusive thrombosis of the coronary artery is the principal cause of myocardial infarction where platelets play an important role. Large size platelets, easily measured by mean platelets volume (MPV) are thrombogenic and commonly seen after ST-segment elevation myocardial infarction (STEMI). ST segment resolution has been shown as a simple non-invasive marker that reflects both epicardial and myocardial reperfusion following thrombolysis. The present study intended to investigate whether MPV on admission correlated with ST segment resolution following thrombolysis in STEMI patient. This cross-sectional analytical study was conducted in the department of cardiology, Mymensingh Medical College and Hospital (MMCH), Mymensingh, Bangladesh from December, 2016 to June, 2018. Total 284 patients with first attack of STEMI were included after considering inclusion and exclusion criteria. Sample population was divided into two groups, Group I - Patients with successful ST segment resolution (≥50%). Group II - Patients with impaired ST segment resolution (<50%). MPV on admission was estimated during estimation of Complete Blood Count (CBC) by Automated Haematology Analyzer & compared between two groups. Successful ST segment resolution (≥50%) was seen in 67% of patients after thrombolysis. Admission MPV was higher in patients with impaired ST segment resolution (<50%) group than patients with ≥50% ST-segment resolution group (12.42±0.89fl vs.10.35±0.77fl respectively, p=0.001). Statistically significant strong negative correlation between MPV and ST segment resolution percentage (r = -0.742, p=0.001) suggesting that the higher the level of MPV, the lower the ST segment resolution percentage in first attack of STEMI patients. Multivariate regression analysis found MPV level on admission as an independent predictor of ST segment resolution. The study concluded that high MPV on admission correlate with impaired ST segment resolution following thrombolysis in STEMI patients.

Antithyroid Antibody Status in Non-Pregnant Adult Bangladeshi Patients with Subclinical Hypothyroidism.

Sub clinical hypothyroidism (SCH) is common in clinical practice. Autoimmunity is thought to be the most important cause of SCH. In this cross-sectional study, we investigated 120 SCH patients and 100 healthy controls attending the Endocrinology Outpatient Department of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from June 2014 to April 2015 for anti-thyroid antibodies (anti-TPO and anti-Tg). Measurement of serum TSH, FT4, anti-TPO, and anti-Tg antibodies were done by using the chemiluminescent sequential immunometric assay. SCH patients had a higher mean age; the frequencies of female subjects, those having family history of thyroid disease or other autoimmune diseases, and goiter were higher in SCH group than in the control group. Forty-five percent (45%) of SCH patients were positive for anti-thyroid antibodies (23.3% for both anti-TPO and anti-Tg, 16.7% for only anti-TPO, and 5% positive for only anti-Tg) in comparison to only 10% anti-thyroid antibody positive controls (none for both antibodies, 8% for only anti-TPO, and 2% positive for only anti-Tg). The SCH subjects in the lower age group, females and with a TSH >10µIU/mL had the higher frequency of thyroid autoimmunity. Female gender, high socioeconomic condition, the presence of other autoimmune diseases, the presence of goiter and TSH >10µIU/mL were associated with higher odds of anti-thyroid antibody positivity in the SCH group, though none were statistically significant. The frequency of anti-thyroid antibody was higher in SCH and was more prevalent among the females, younger patients and those having a goiter, other autoimmune diseases, and TSH >10µIU/mL.

Regioselectivity in the reductive bond cleavage of diarylalkylsulfonium salts: variation with driving force and structure of sulfuranyl radical intermediates.

This investigation was stimulated by reports that one-electron reductions of monoaryldialkylsulfonium salts never give aryl bond cleavage whereas reductions of diarylmonoalkylsulfonium salts preferentially give aryl bond cleavage. We studied the product ratios from the reductive cleavage of di-4-tolylethylsulfonium and di-4-tolyl-2-phenylethylsulfonium salts by a variety of one-electron reducing agents ranging in potential from -0.77 to +2.5 eV (vs SCE) and including thermal reductants, indirect electrolyses mediated by a series of cyanoaromatics, and excited singlet states. We report that the cleavage products vary from regiospecific alkyl cleavage to predominant aryl cleavage as a function of the potential of the reducing agent. We conclude that differences between the reductive cleavages of mono- and diarylsulfonium salts are direct consequences of the structures of the sulfuranyl radical intermediates and the bond dissociation energies of the alkyl and aryl bonds. Competitions between the rates of cleavage and oxidation of the intermediate sulfuranyl radicals and between concerted and stepwise mechanisms are discussed to explain the variations in bond cleavage products as a function of the driving forces for the reductions. Density functional theory investigations of the nature of the antibonding S-alkyl and S-aryl orbitals of the starting sulfonium salts provide additional insight.

DPC4, a candidate tumor suppressor gene at human chromosome 18q21.1.

About 90 percent of human pancreatic carcinomas show allelic loss at chromosome 18q. To identify candidate tumor suppressor genes on 18q, a panel of pancreatic carcinomas were analyzed for convergent sites of homozygous deletion. Twenty-five of 84 tumors had homozygous deletions at 18q21.1, a site that excludes DCC (a candidate suppressor gene for colorectal cancer) and includes DPC4, a gene similar in sequence to a Drosophila melanogaster gene (Mad) implicated in a transforming growth factor-beta (TGF-beta)-like signaling pathway. Potentially inactivating mutations in DPC4 were identified in six of 27 pancreatic carcinomas that did not have homozygous deletions at 18q21.1. These results identify DPC4 as a candidate tumor suppressor gene whose inactivation may play a role in pancreatic and possibly other human cancers.

Effects of in utero arsenic exposure on child immunity and morbidity in rural Bangladesh.

Chronic exposure to arsenic, a potent carcinogen and toxicant, via drinking water is a worldwide public health problem. Because little is known about early-life effects of arsenic on immunity, we evaluated the impact of in utero exposure on infant immune parameters and morbidity in a pilot study. Pregnant women were enrolled at 6-10 weeks of gestation in Matlab, a rural area of Bangladesh, extensively affected by arsenic contamination of tubewell water. Women (n=140) delivering at local clinics were included in the study. Anthropometry and morbidity data of the pregnant women and their children, as well as infant thymic size by sonography were collected. Maternal urine and breast milk were collected for immune marker and arsenic assessment. Maternal urinary arsenic during pregnancy showed significant negative correlation with interleukin-7 (IL-7) and lactoferrin (Ltf) in breast milk and child thymic index (TI). Urinary arsenic was also positively associated with fever and diarrhea during pregnancy and acute respiratory infections (ARI) in the infants. The effect of arsenic exposure on ARI was only evident in male children. The findings suggest that in utero arsenic exposure impaired child thymic development and enhanced morbidity, probably via immunosuppression. The effect seemed to be partially gender dependent. Arsenic exposure also affected breast milk content of trophic factors and maternal morbidity.

Household solid waste characteristics and management in Chittagong, Bangladesh.

Solid waste management (SWM) is a multidimensional challenge faced by urban authorities, especially in developing countries like Bangladesh. We investigated per capita waste generation by residents, its composition, and the households' attitudes towards waste management at Rahman Nagar Residential Area, Chittagong, Bangladesh. The study involved a structured questionnaire and encompassed 75 households from five different socioeconomic groups (SEGs): low (LSEG), lower middle (LMSEG), middle (MSEG), upper middle (UMSEG) and high (HSEG). Wastes, collected from all of the groups of households, were segregated and weighed. Waste generation was 1.3 kg/household/day and 0.25 kg/person/day. Household solid waste (HSW) was comprised of nine categories of wastes with vegetable/food waste being the largest component (62%). Vegetable/food waste generation increased from the HSEG (47%) to the LSEG (88%). By weight, 66% of the waste was compostable in nature. The generation of HSW was positively correlated with family size (r xy=0.236, p<0.05), education level (r xy=0.244, p<0.05) and monthly income (r xy=0.671, p<0.01) of the households. Municipal authorities are usually the responsible agencies for solid waste collection and disposal, but the magnitude of the problem is well beyond the ability of any municipal government to tackle. Hence dwellers were found to take the service from the local waste management initiative. Of the respondents, an impressive 44% were willing to pay US dollars 0.3 to US dollars 0.4 per month to waste collectors and it is recommended that service charge be based on the volume of waste generated by households. Almost a quarter (22.7%) of the respondents preferred 12-1 pm as the time period for their waste to be collected. This study adequately shows that household solid waste can be converted from burden to resource through segregation at the source, since people are aware of their role in this direction provided a mechanism to assist them in this pursuit exists and the burden is distributed according to the amount of waste generated.

Comparative Study between the Use of Multidose Standard Cardioplegia and Long Acting Del Nido Cardioplegia during Intracardiac Repair for Tetralogy of Fallot in Pediatric Patients.

Pediatric myocardium is unique from mature myocardium; thus, the use of adult cardioplegia for pediatric cardiac operations may provide suboptimal myocardial protection. It is found that children undergoing heart surgery show evidence of less myocardial damage when del Nido cardioplegia is used instead of a standard cardioplegic solution. Del Nido cardioplegia solution provides a depolarized hyperkalaemic arrest lasting up to 60 minutes, reduces spontaneous and inducible activity during arrest, and prevents hyper contraction during early reperfusion. In this single blind randomized trial, a total of 60 patients underwent intra cardiac repair for TOF in National Institute of Cardiovascular Diseases, Dhaka, Bangladesh from July 2014 to January 2016 fulfilling inclusion and exclusion criteria. They were randomly assigned in two groups- 30 patients in Del Nido group (Group A) and 30 patients in standard group (Group B). Comparison between groups was done by Chi square test and Student's test. All data were analyzed by SPSS 20.0 for windows. P value less than 0.05 was considered as significant. There was statistically significant difference among the patients in terms of mean total initial cardioplegia volume, mean number of additional dose, mean additional dose amount, mean cross clamp time, mean CPB time (331.67±188.07 vs. 458.67±226.62, p=0.022; 0.13±0.35 vs. 1.27±0.89, p=0.000; 23.33±60.76 vs. 336.83±259.6, p=0.000; 45.10±10.35 vs. 59.23±23.21, p=0.003; 89.30±15.73 vs. 111.10±29.23, p=0.001 respectively). Mean post operative serum troponin I level at arrival in ICU and after 24 hours between two groups were statistically significantly different (55.60±32.91 vs. 83.5±58.99; p=0.024 and 13.01±5.84 vs. 18.16±9.51; p=0.014 respectively). The mean ventilation duration, mean ICU stay were also statistically significant. This study showed that cardiac arrest with Del Nido cardioplegia during intra cardiac repair for TOF was associated with improved myocardial protection over standard cardioplegia in terms of reduced CPB and cross clamp times, lower total volume of cardioplegia.

Introduction of routine zinc therapy for children with diarrhoea: evaluation of safety.

On 8 May 2004, the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF) recommended routine administration of zinc in the management of children, aged less than five years, with acute diarrhoea. In making the recommendation, WHO and UNICEF also suggested careful monitoring for adverse events associated with routine administration of zinc, particularly unusual or excess vomiting. The study assessed, in a phase IV trial, i.e. post-marketing surveillance of zinc, the occurrence of adverse events during the first hour after the administration of the first dose of zinc in children with acute or persistent diarrhoea. The study was conducted at the Dhaka Hospital of ICDDR,B and at an outpatient clinic operated by a local health NGO-Progoti Samaj Kallyan Protisthan (PSKP), Dhaka, Bangladesh. Eligible children, aged 3-59 months, were treated with 20 mg of zinc sulphate provided in a dispersible tablet formulation. The children were observed for 60 minutes following the initial treatment with zinc for adverse events, with particular attention given to vomiting or regurgitation. During the one-year observation period, 42,440 children (male 57% and female 43%) received zinc, and 20,246 (47.8%) of them were observed. Regurgitation and/or vomiting occurred in 4,392 (21.8%) of the children; 90.8% of these children had vomiting only once, 8.7% twice, and 0.5% more than twice. No children revisited the hospital for recurrent vomiting following their discharge. A significant proportion of infants and children may experience vomiting or regurgitation, usually once, following the administration of the first dose of zinc. This is a transient phenomenon that did not impact on continuation of treatment with zinc.

Arsenic in Bangladeshi soils related to physiographic region, paddy management, and mirco- and macro-elemental status.

While the impact of arsenic in irrigated agriculture has become a major environmental concern in Bangladesh, to date there is still a limited understanding of arsenic in Bangladeshi paddy soils at a landscape level. A soil survey was conducted across ten different physiographic regions of Bangladesh, which encompassed six types of geomorphology (Bil, Brahmaputra floodplain, Ganges floodplain, Meghna floodplain, Karatoya-Bangali floodplain and Pleistocene terrace). A total of 1209 paddy soils and 235 matched non-paddy soils were collected. The source of irrigation water (groundwater and surface water) was also recorded. The concentrations of arsenic and sixteen other elements were determined in the soil samples. The concentration of arsenic was higher in paddy soils compared to non-paddy soils, with soils irrigated with groundwater being higher in arsenic than those irrigated with surface water. There was a clear difference between the Holocene floodplains and the Pleistocene terraces, with Holocene floodplain soils being higher in arsenic and other elements. The results suggest that arsenic is most likely associated with less well weathered/leached soils, suggesting it is either due to the geological newness of Holocene sediments or differences between the sources of sediments, which gives rise to the arsenic problems in Bangladeshi soils.

Mutagen sensitivity as a risk factor for second malignant tumors following malignancies of the upper aerodigestive tract.

BACKGROUND: Second malignant tumors in patients successfully treated for an initial cancer of the upper aerodigestive tract are an important cause of morbidity and mortality. Biologic markers capable of identifying high-risk subgroups of patients who could be targeted for intensive clinical surveillance, therefore, have immense therapeutic and prognostic relevance. We previously demonstrated in a pilot study of 84 patients with cancers of the upper aerodigestive tract that mutagen sensitivity was a significant predictor of risk of developing second malignant tumors. PURPOSE: We extended the study to include 278 patients diagnosed with previously untreated cancers of the upper aerodigestive tract from 1987 to August 1993. METHODS: For each patient, base-line (pretreatment) mutagen sensitivity was measured in vitro in 50 metaphases established from peripheral lymphocyte cultures. Patients with an average of more than 1 chromosomal break/cell were deemed mutagen hypersensitive. Cox proportional hazards analysis was used to predict the risk of developing second malignant tumors associated with mutagen sensitivity. RESULTS: Overall, 44% of the case group exhibited mutagen hypersensitivity. There were no differences in the distribution of mutagen hypersensitivity by site, sex, stage of disease, or smoking status. There were 17 synchronous and 11 metachronous cancers, of which 15 (54%) were smoking-related malignancies. Sixteen (13.1%) of the mutagen-sensitive patients developed second malignant tumors, compared with 12 (7.7%) of the nonsensitive patients. The mean break/cell value (+/- SD) for patients developing second malignant tumors was 1.17 (+/- 0.54), compared with 0.98 (+/- 0.44) for patients with only one cancer (P = .04). Mutagen hypersensitivity conferred a relative risk of 2.67 (95% confidence interval = 1.22-5.79) of developing second malignant tumors. CONCLUSIONS: Mutagen hypersensitivity increases the risk of developing second malignant tumors. IMPLICATIONS: Future research should focus on the molecular mechanisms underlying mutagen sensitivity.