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.

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.

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.

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 chisquare 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

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.

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.

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.

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.

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.

In utero arsenic exposure is associated with impaired thymic function in newborns possibly via oxidative stress and apoptosis.

Prenatal arsenic exposure is associated with increased infant morbidity and reduced thymus size, indicating arsenic-related developmental immunotoxicity. We aimed to evaluate effects of prenatal arsenic exposure on thymic function at birth and related mechanisms of action. In a Bangladeshi cohort, arsenic was measured in urine (U-As, gestational week (GW) 8 and 30) and blood (B-As, GW14) in 130 women. Child thymic index was measured by sonography at birth and thymic function by signal-joint T-cell receptor-rearrangement excision circles (sjTRECs) in cord blood mononuclear cells (CBMC). In a subsample (n = 44), sjTRECs content in isolated CD4(+) and CD8(+) T cells, expression of oxidative-stress defense and apoptosis-related genes in CBMC, arsenic concentrations (urine, placenta, and cord blood), and oxidative stress markers in placenta and cord blood were measured. In multivariable-adjusted regression, ln U-As (GW8) was inversely associated with ln sjTRECs in CBMC (B = -0.25; 95% confidence interval [CI] -0.48 to -0.01). Using multivariable-adjusted spline regression, ln U-As (GW30) and ln B-As (GW14) were inversely associated with ln sjTRECs in CBMC (B = -0.53; 95% CI -0.93 to -0.13 and B = -1.27; 95% CI -1.89 to -0.66, respectively) below spline knots at U-As 150 µg/l and B-As 6 µg/kg. Similar inverse associations were observed in separated CD4(+) and CD8(+) T cells. Arsenic was positively associated with 8-hydroxy-2'-deoxyguanosine in cord blood (B = 0.097; 95% CI 0.05 to 0.13), which was inversely associated with sjTRECs in CD4(+) and CD8(+) T cells. In conclusion, prenatal arsenic exposure was associated with reduced thymic function, possibly via induction of oxidative stress and apoptosis, suggesting subsequent immunosuppression in childhood.

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.

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.

Arsenic methylation efficiency increases during the first trimester of pregnancy independent of folate status.

Exposure to inorganic arsenic during pregnancy may negatively influence the offspring, though efficient metabolism of arsenic to dimethylarsinic acid (DMA) likely reduces the health risks. This study aimed to evaluate methylation of arsenic over the entire pregnancy and the influence of nutritional status. We studied longitudinally the arsenic metabolite pattern in the urine of 324 pregnant women exposed to arsenic via drinking water and food in rural Bangladesh. Metabolism of arsenic to DMA increased markedly over the course of pregnancy, with the greatest improvement occurring in the first trimester, along with a marked decrease in the most risk-associated monomethylated metabolite. This improvement in methylation was not associated with nutritional status, including vitamin B(12) and folate. Efficient methylation to DMA was associated with improved urinary excretion of arsenic, relative to blood arsenic concentrations, indicating that micronutrient-independent up-regulation of arsenic metabolism already in early pregnancy may provide protection for the fetus.

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.

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.

Compliance to Intake of Prenatal Supplements among Rural Pregnant Women - an Observational Study in Two Sub-districts in Rural Bangladesh.

A cross-sectional observational study was undertaken to determine the compliance to intake of food and micronutrient supplements among 48 rural pregnant women in two sub-districts under two Divisions of Bangladesh. All pregnant women were observed from 8am to 2pm everyday for three consecutive days. Results shows that only 27.1% of the pregnant women consumed the full packet of food supplements, 43.1% shared it with other members of their family and 29.2% did not go to collect the supplement. A total of 93.8 % women did not consume the micronutrients, iron or folate supplements during the time of observation. Necessary steps should be taken to improve delivery strategies of supplements among rural pregnant women in Bangladesh, which should include training of the service providers and health education to the pregnant women.

Accumulation of cadmium in human placenta interacts with the transport of micronutrients to the fetus.

Cadmium (Cd) is a widespread, highly toxic environmental pollutant known to accumulate in human placenta. The aim of the present study was to elucidate to what extent the accumulation of Cd in human placenta interacts with the transport of micronutrients to the fetus. Cd and micronutrients were measured in placenta and umbilical cord blood from 44 non-smoking, rural Bangladeshi women, using ICPMS. Metallothionein (MT) protein expression was determined in placenta using Western blot. Cd in placenta (median 110 microg/kg dry weight, 20 microg/kg wet weight) was positively associated with maternal urinary Cd. It was also positively associated with Cd in umbilical cord blood (median 0.16 microg/kg), but negatively associated with zinc (Zn; median 3mg/kg) in umbilical cord blood. Umbilical cord blood Zn was positively associated with birth anthropometry measures, and the Cd-related impairment of Zn in umbilical cord blood seemed to decrease size at birth. In multivariate analysis, MT protein expression was associated with Cd (positively) in placenta, but not with Zn or copper (Cu) in placenta. In conclusion, the Cd concentrations in placenta were clearly elevated, which seemed to impair Zn transfer to the fetus. Induction of MT explained the placental accumulation of Cd, but not the impairment of Zn transport.

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.