Vinita Das

Diffusion tensor imaging of the developing human cerebrum

Diffusion tensor imaging (DTI) was performed on 15 fresh spontaneously or therapeutically aborted normal fetuses and five term infants at different gestational ages. Regional cortical fractional anisotropy (FA) values were observed to increase with gestational age (GA) from 15 to 28 weeks, followed by a decrease through 36 weeks. The early increase in the cortical FA value, which has never been reported before, is consistent with neuronal migration from the germinal matrix. A statistically significant inverse correlation between GA and the FA values in the germinal matrix was observed (r = –0.81, P = 0.004). In addition, there was a significant difference in the FA values in the right and left frontal cortices (P = 0.007, sign test), suggesting cortical lateralization during the early stage of development. Our studies suggest that the DTI‐estimated anisotropy could be useful in following neuronal migration, cortical maturation, and associated changes in the germinal matrix during early brain development.

Vitamin D deficiency in rural girls and pregnant women despite abundant sunshine in northern India

Context  Vitamin D deficiency is common in urban Indians despite living in the tropics and its public health consequences are enormous. However, 70% of India is rural, and data from rural subjects, who are expected to have good sun exposure, are scant.

Population Health Metrics Research Consortium gold standard verbal autopsy validation study: design, implementation, and development of analysis datasets

BackgroundVerbal autopsy methods are critically important for evaluating the leading causes of death in populations without adequate vital registration systems. With a myriad of analytical and data collection approaches, it is essential to create a high quality validation dataset from different populations to evaluate comparative method performance and make recommendations for future verbal autopsy implementation. This study was undertaken to compile a set of strictly defined gold standard deaths for which verbal autopsies were collected to validate the accuracy of different methods of verbal autopsy cause of death assignment.MethodsData collection was implemented in six sites in four countries: Andhra Pradesh, India; Bohol, Philippines; Dar es Salaam, Tanzania; Mexico City, Mexico; Pemba Island, Tanzania; and Uttar Pradesh, India. The Population Health Metrics Research Consortium (PHMRC) developed stringent diagnostic criteria including laboratory, pathology, and medical imaging findings to identify gold standard deaths in health facilities as well as an enhanced verbal autopsy instrument based on World Health Organization (WHO) standards. A cause list was constructed based on the WHO Global Burden of Disease estimates of the leading causes of death, potential to identify unique signs and symptoms, and the likely existence of sufficient medical technology to ascertain gold standard cases. Blinded verbal autopsies were collected on all gold standard deaths.ResultsOver 12,000 verbal autopsies on deaths with gold standard diagnoses were collected (7,836 adults, 2,075 children, 1,629 neonates, and 1,002 stillbirths). Difficulties in finding sufficient cases to meet gold standard criteria as well as problems with misclassification for certain causes meant that the target list of causes for analysis was reduced to 34 for adults, 21 for children, and 10 for neonates, excluding stillbirths. To ensure strict independence for the validation of methods and assessment of comparative performance, 500 test-train datasets were created from the universe of cases, covering a range of cause-specific compositions.ConclusionsThis unique, robust validation dataset will allow scholars to evaluate the performance of different verbal autopsy analytic methods as well as instrument design. This dataset can be used to inform the implementation of verbal autopsies to more reliably ascertain cause of death in national health information systems.

Using verbal autopsy to measure causes of death: the comparative performance of existing methods

BackgroundMonitoring progress with disease and injury reduction in many populations will require widespread use of verbal autopsy (VA). Multiple methods have been developed for assigning cause of death from a VA but their application is restricted by uncertainty about their reliability.MethodsWe investigated the validity of five automated VA methods for assigning cause of death: InterVA-4, Random Forest (RF), Simplified Symptom Pattern (SSP), Tariff method (Tariff), and King-Lu (KL), in addition to physician review of VA forms (PCVA), based on 12,535 cases from diverse populations for which the true cause of death had been reliably established. For adults, children, neonates and stillbirths, performance was assessed separately for individuals using sensitivity, specificity, Kappa, and chance-corrected concordance (CCC) and for populations using cause specific mortality fraction (CSMF) accuracy, with and without additional diagnostic information from prior contact with health services. A total of 500 train-test splits were used to ensure that results are robust to variation in the underlying cause of death distribution.ResultsThree automated diagnostic methods, Tariff, SSP, and RF, but not InterVA-4, performed better than physician review in all age groups, study sites, and for the majority of causes of death studied. For adults, CSMF accuracy ranged from 0.764 to 0.770, compared with 0.680 for PCVA and 0.625 for InterVA; CCC varied from 49.2% to 54.1%, compared with 42.2% for PCVA, and 23.8% for InterVA. For children, CSMF accuracy was 0.783 for Tariff, 0.678 for PCVA, and 0.520 for InterVA; CCC was 52.5% for Tariff, 44.5% for PCVA, and 30.3% for InterVA. For neonates, CSMF accuracy was 0.817 for Tariff, 0.719 for PCVA, and 0.629 for InterVA; CCC varied from 47.3% to 50.3% for the three automated methods, 29.3% for PCVA, and 19.4% for InterVA. The method with the highest sensitivity for a specific cause varied by cause.ConclusionsPhysician review of verbal autopsy questionnaires is less accurate than automated methods in determining both individual and population causes of death. Overall, Tariff performs as well or better than other methods and should be widely applied in routine mortality surveillance systems with poor cause of death certification practices.

Effect of vitamin D supplementation during pregnancy on neonatal mineral homeostasis and anthropometry of the newborn and infant

Hypovitaminosis D is common in India. In the present prospective partially randomised study of vitamin D (D₃) supplementation during pregnancy, subjects were randomised in the second trimester to receive either one oral dose of 1500 μg vitamin D₃ (group 1, n 48) or two doses of 3000 μg vitamin D₃ each in the second and third trimesters (group 2, n 49). Maternal 25-hydroxyvitamin D (25(OH)D) at term, cord blood (CB) alkaline phosphatase (ALP), neonatal serum Ca and anthropometry were measured in these subjects and in forty-three non-supplemented mother-infant pairs (usual care). Median maternal 25(OH)D at term was higher in group 2 (58·7, interquartile range (IQR) 38·4-89·4 nmol/l) v. group 1 (26·2, IQR 17·7-57·7 nmol/l) and usual-care group (39·2, IQR 21·2-73·4 nmol/l) (P = 0·000). CB ALP was increased (>8.02 μkat/l or >480 IU/l) in 66·7 % of the usual-care group v. 41·9 % of group 1 and 38·9 % of group 2 (P = 0·03). Neonatal Ca and CB 25(OH)D did not differ significantly in the three groups. Birth weight, length and head circumference were greater and the anterior fontanelle was smaller in groups 1 and 2 (3·08 and 3·03 kg, 50·3 and 50·1 cm, 34·5 and 34·4 cm, 2·6 and 2·5 cm, respectively) v. usual care (2·77 kg, 49·4, 33·6, 3·3 cm; P = 0·000 for length, head circumference and fontanelle and P = 0·003 for weight). These differences were still evident at 9 months. We conclude that both 1500 μg and two doses of 3000 μg vitamin D₃ had a beneficial effect on infant anthropometry, the larger dose also improving CB ALP and maternal 25(OH)D.

Impact of maternal body mass index on obstetric outcome

Aim:  The purpose of the present study was to correlate effect of maternal body mass index (BMI) on obstetric outcome. The studies conducted so far are from Western developed countries and there is a paucity of data from developing countries.

Diffusion tensor imaging in the developing human cerebellum with histologic correlation

Diffusion tensor imaging was performed on 24 freshly aborted human fetuses with gestational age ranging from 20 to 37 weeks to observe age‐related fractional anisotropy changes in cerebellar cortex and cerebellar white matter. Quantitative immunohistochemical analysis was performed for glial fibrillary acidic protein in each fetus molecular layer of cerebellar cortex and myelin basic protein expression was quantified in myelinated areas of the middle cerebellar peduncles. The cerebellar cortical fractional anisotropy reached its peak value at 28 weeks, and then decreased gradually until 37 weeks. The time course of glial fibrillary acidic protein expression paralleled that of fractional anisotropy in the cerebellar cortex from 20 weeks of gestation upto the gestational age at which the fractional anisotropy reached its peak value (28 weeks). In the middle cerebellar peduncles, the fractional anisotropy increased continuously upto 37 weeks of gestational age and showed a significant positive correlation with myelin basic protein immunostained fibers. The fractional anisotropy quantification can be used to assess the migrational and maturation changes during the development of the human fetal cerebellum supported by the immunohistochemical analysis.

HLA Sharing, Anti‐Paternal Cytotoxic Antibodies and MLR Blocking Factors in Women with Recurrent Spontaneous Abortion

Objective: To study the prevalence of HLA sharing between spouses and its correlation with presence of antipaternal cytotoxic antibody (APCA) and mixed lymphocyte reaction (MLR) blocking factors in recurrent spontaneous aborters (RSA).

Community-driven impact of a newborn-focused behavioral intervention on maternal health in Shivgarh, India.

To assess the effect on maternal health outcomes of a community‐based behavior change management intervention for essential newborn care leading to a reduction in neonatal mortality.

MTHFR 677C→T and 1298A→C Polymorphisms: Evaluation of Maternal Genotypic Risk and Association with Level of Neural Tube Defect

Background: Neural tube defects (NTDs) are common birth defects (1 in 1,000) leading to significant morbidity and mortality. Periconceptional folic acid supplementation helps in prevention of 70% of NTDs. Recently, polymorphisms in genes encoding enzymes of the folate pathway have been implicated in causation of NTDs. Since the closure of neural tube occurs at multiple sites, the etiology of defect at different sites may be different – which explains the failure of folic acid supplementation to prevent all NTDs. Methods: Molecular analysis of methylenetetrahydrofolate reductase polymorphisms was carried out using polymerase chain reaction and restriction enzyme digestion. We studied the association of these polymorphisms in mothers with a previous child with NTD and further refined the risk by stratification based on level of defect. Results: The frequency of 677C→T homozygotes was higher in mothers with a previous child with NTD than the controls (OR = 1.6 (0.38–6.7), 95% CI, p = 0.72) but the difference was statistically insignificant. There was a significant difference in frequency of T alleles among mothers with a previous child with a ‘lower’ type of defect compared to controls (OR = 2.15 (1.13–4.1), 95% CI, p = 0.02). We did not find any significant association of 1298A→C polymorphism with the level of NTDs. Conclusions: We conclude that in the North Indian population, the 677C→T allele of the MTHFR gene may be associated with the occurrence of a lower type of NTD. This points towards the differential role of thermolabile MTHFR at different sites of neural tube closure.