Erythropoietin and ferritin response in native highlanders aged 4-19 years from the Leh-Ladakh region of India.

The pivotal role of erythropoietin (EPO) in hypoxic adaptation has led to various studies assessing the EPO and ferritin response in native highlanders from Andes and Tibet. We assessed the relationship between EPO, haemoglobin and ferritin in 335 native highlanders (172 boys and 163 girls, aged 4 to 19 years) from Leh-Ladakh, India, who had no history of travel to lowland areas. Complete blood counts, serum EPO and ferritin levels were measured. We stratified study subjects based on age, gender, pubertal status and analysed the EPO and ferritin levels between the stratified groups respectively. The mean EPO level in boys was lower than girls. The mean ferritin level in boys was significantly higher (P = 0·013) than in girls. There was no significant variation in the EPO and ferritin levels amongst the various age groups in our study. Near normal EPO levels since childhood with a negative correlation with haemoglobin is suggestive of a robust adaptive mechanism to high altitude from the early years of life. Low ferritin levels are indicative of decreased iron stores in these native highlanders.

Comparison of Optic Nerve Sheath Diameter between both eyes: A Bedside Ultrasonography Approach.

CONTEXT: Optic nerve sheath diameter (ONSD) has long been accepted as a reliable proxy of intracranial pressure especially in critical care and bedside settings. The present consensus is to measure ONSD in both eyes and take average value, which is cumbersome and a potential cause of discomfort to the patient. AIM: We aim to compare the values of ONSD of the right and left eye in a random sample as measured by bedside ocular ultrasonography (USG) in Indian adults. SETTINGS AND DESIGN: This was a prospective study conducted from September 2012 to March 2013 in the Department of Internal Medicine of a tertiary care hospital situated at moderate high altitude (11,500 ft) in India. MATERIALS AND METHODS: Patients admitted with high altitude pulmonary edema (HAPE) were recruited by convenience sampling. The ONSD of both eyes were measured 3 mm behind the globe using a 7.5 MHz linear probe on the closed eyelids of supine subjects. STATISTICAL ANALYSIS: Analysis was done using SPSS 17.0. RESULTS: A total of 47 patients of HAPE were recruited to the study with daily ONSD recording of both eyes during the admission period. The mean ONSD of the left eye was 4.60 (standard deviation [SD] = 0.71) whereas the mean ONSD of right eye 4.59 (SD = 0.72). The ONSD of the right eye and left eye was strongly correlated (correlation coefficient = 0.98 with P < 0.0001). The mean difference in the ONSD of both eyes (right-left) was -0.0044 (SD = 0.11) which was not statistically significant (P = 0.533). CONCLUSION: Our results suggest that the difference in ONSD of both eyes is not statistically significant in disease or health. This study also suggests that the ONSD of either eye can be predicted by the other eye recordings. Based on these findings, it can be suggested that during ocular USG for routine bedside/research purposes it is sufficient to measure ONSD of any of the one eye to save time and avoid discomfort to the patient.

Hematological Parameters in Native Highlanders of Ladakh Aged 4-19 Years.

Hematological adaptations to high altitude (HA) are long studied but are focused either on lowlanders visiting HA or native highlanders from Andes and Tibet. The literature on native highlanders from the Indian subcontinent or paediatric highlanders is scarce. We aimed at assessing hematological parameters in native highlanders of Ladakh, India, aged 4-19 years and derive nomograms in an age stratified manner specific to these native highlanders. A total of 335 self-reported healthy native highlanders of Ladakh, without any known comorbidities and not on hematinic nor any drugs in the age group of 4-19 years were included in the study. Complete hemogram including red cell indices was measured. R ver 3.4.0 was used to compare the hematological parameters based on gender/age stratification, pubertal and nutritional status. The hematological reference ranges were created for various parameters in the paediatric population. The mean (SD) haemoglobin (Hb) concentration was 14.74 (2.07) gm/dL. The mean hematocrit (Hct) was 40.43 (5.57%) %, mean corpuscular volume (MCV) was 81.87 (7.22) fL, white blood cell (WBC) count was 7596 (2172) cells/µL and platelets was 378.4 (152.8) × 103/µL. Hct and MCV increased with age. Hb concentration, Hct, and MCV in girls was significantly lower than boys. Severely underweight subjects (body mass index < 16) showed significantly higher platelet counts compared to their nourished counterparts. The hematological nomograms for the native paediatric highlanders from Ladakh, India have been reported in this study.

A new route to enhance the ferromagnetic transition temperature in diluted magnetic semiconductors.

We investigate the magnetic and the transport properties of diluted magnetic semiconductors using a spin-fermion Monte-Carlo method on a simple cubic lattice in the intermediate coupling regime. The ferromagnetic transition temperature T c shows an optimization behavior with respect to the absolute carrier density p abs and the magnetic impurity concentration x as seen in the experiments. Our calculations also show an insulator-metal-insulator transition across the optimum p abs where the T c is maximum. Remarkably, the optimum p abs values lie in a narrow range around 0.11 (holes/site) for all x values and the ferromagnetic T c increases with x. We explain our results using the polaron percolation mechanism and outline a new route to enhance the ferromagnetic transition temperature in experiments.