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A baseline data has been presented here to prove that among the abiotic factors, temperature is the most critical factor that regulates and governs the bacterial diversity in a natural ecosystem. Present study in Yumesamdong hot springs riverine vicinity (Sikkim), parades a gamut of bacterial communities in it and hosts them from semi-frigid region (- 4-10 °C) to fervid region (50-60 °C) via an intermediate region (25-37 °C) within the same ecosystem. This is an extremely rare intriguing natural ecosystem that has no anthropogenic disturbances nor any artificial regulation of temperature. We scanned the bacterial flora through both the culture-dependent and culture-independent techniques in this naturally complex thermally graded habitat. High-throughput sequencing gave bacterial and archaeal phyla representatives of over 2000 species showcasing their biodiversity. Proteobacteria, Firmicutes, Bacteroidetes and Chloroflexi were the predominant phyla. A concave down-curve significance was found in temperature-abundance correlation as the number of microbial taxa decreased when the temperature increased from warm (35 °C) to hot (60 °C). Firmicutes showed significant linear increase from cold to hot environment whereas Proteobacteria followed the opposite trend. No significant correlation was observed for physicochemical parameters against the bacterial diversity. However, only temperature has shown significant positive correlation to the predominant phyla at their respective thermal gradients. The antibiotic resistance patterns correlated with temperature gradient where the prevalence of antibiotic resistance was higher in case of mesophiles than that of psychrophiles and there was no resistance in thermophiles. The antibiotic resistant genes obtained were solely from mesophiles as it conferred high resistance at mesophilic conditions enabling them to adapt and metabolically compete for survival. Our study concludes that the temperature is a major factor that plays a significant contribution in shaping the bacterial community structure in any thermal gradient edifice., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Here we present the construction and characterization of metagenome assembled genomes (MAGs) from two hot springs residing in the vicinity of Indian Himalayan Geothermal Belt (IHGB). A total of 78 and 7 taxonomic bins were obtained for Old Yume Samdong (OYS) and New Yume Samdong (NYS) hot springs respectively. After passing all the criteria only 21 and 4 MAGs were further studied based on the successful prediction of their 16 S rRNA. Various databases were used such as GTDB, Kaiju, EzTaxon, BLAST XY Plot and NCBI BLAST to get the taxonomic classification of various 16 S rRNA predicted MAGs. The bacterial genomes found were from both thermophilic and mesophilic bacteria among which Proteobacteria, Chloroflexi, Bacteroidetes and Firmicutes were the abundant phyla. However, in case of OYS, two genomes belonged to archaeal Methanobacterium and Methanocaldococcus. Functional characterization revealed the richness of CAZymes such as Glycosyl Transferase (GT) (56.7%), Glycoside Hydrolase (GH) (37.4%), Carbohydrate Esterase family (CE) (8.2%), and Polysaccharide Lyase (PL) (1.9%). There were negligible antibiotic resistance genes in the MAGs however, a significant heavy metal tolerance gene was found in the MAGs. Thus, it may be assumed that there is no coexistence of antibiotic and heavy metal resistance genes in these hot spring microbiomes. Since the selected hot springs possess good sulfur content thus, we also checked the presence of genes for sulfur and nitrogen metabolism. It was found that MAGs from both the hot springs possess significant number of genes related to sulfur and nitrogen metabolism., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

The solfataric soil sediments of the hot springs of Sikkim located at Yume Samdung and Lachen valley were studied for deciphering the bacterial diversity. The main aim here is to present a comparative study and generate a baseline data on the post-monsoon seasonal variation for the months of October and December, analyzed through 16S rRNA V3-V4 amplicon sequencing. The results have shown that there is not much variation at phylum level in the month of October in all the three hot springs such as New Yume Samdung (NYS), Old Yume Samdung (OYS), and Tarum (TAR) hot spring. The abundant phyla mainly present were Firmicutes, followed by Proteobacteria, Actinobacteria, and Bacteroidetes. Similarly, in the month of December, Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were prevalent; however, the percent relative abundance of these phyla in the month of December is relatively less. Besides this decrease in percent abundance, it was interestingly seen that relatively more phyla were found contributing towards the bacterial diversity in the month of December. Similar to phylum level, at genus level, there was not much variation seen among various prevalent genera of the three studied hot springs in both months. The major genera prevalent in both months among all the three hot springs were followed by Bacillus, Desulfotomaculum, Lactobacillus, and Paenibacillus. A similar trend was also seen at gene level that relative abundance of various genera was higher in the month of October but more genera were found to be contributing towards bacterial diversity in the month of December. Few distinct genera were found to be more abundant in the month of December such as Rhodopirellula and Blastopirellula. The results may conclude that there is not much variation in the abundance and type of bacterial communities during the post-monsoon season in the month of October and December. However, this may be assumed that there is the accumulation or increase in the bacterial communities during the winter (relatively higher temperature among hot springs) and may favor few mesophilic and more thermophilic communities as well., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Elongation of very-long-chain fatty acids protein 6 (ELOVL6), an enzyme regulating elongation of saturated and monounsaturated fatty acids with C12 to C16 to those with C18, has been recently indicated to affect various immune and inflammatory responses; however, the precise process by which ELOVL6-related lipid dysregulation affects allergic airway inflammation is unclear., Objectives: This study sought to evaluate the biological roles of ELOVL6 in allergic airway responses and investigate whether regulating lipid composition in the airways could be an alternative treatment for asthma., Methods: Expressions of ELOVL6 and other isoforms were examined in the airways of patients who are severely asthmatic and in mouse models of asthma. Wild-type and ELOVL6-deficient (Elovl6 -/- ) mice were analyzed for ovalbumin-induced, and also for house dust mite-induced, allergic airway inflammation by cell biological and biochemical approaches., Results: ELOVL6 expression was downregulated in the bronchial epithelium of patients who are severely asthmatic compared with controls. In asthmatic mice, ELOVL6 deficiency led to enhanced airway inflammation in which lymphocyte egress from lymph nodes was increased, and both type 2 and non-type 2 immune responses were upregulated. Lipidomic profiling revealed that the levels of palmitic acid, ceramides, and sphingosine-1-phosphate were higher in the lungs of ovalbumin-immunized Elovl6 -/- mice compared with those of wild-type mice, while the aggravated airway inflammation was ameliorated by treatment with fumonisin B1 or DL-threo-dihydrosphingosine, inhibitors of ceramide synthase and sphingosine kinase, respectively., Conclusions: This study illustrates a crucial role for ELOVL6 in controlling allergic airway inflammation via regulation of fatty acid composition and ceramide-sphingosine-1-phosphate biosynthesis and indicates that ELOVL6 may be a novel therapeutic target for asthma., (Copyright © 2023 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Ventilatory acclimatization (VA) is important to maintain adequate oxygenation with ascent to high altitude (HA). Transient hypoxic ventilatory response tests lack feasibility and fail to capture the integrated steady-state responses to chronic hypoxic exposure in HA fieldwork. We recently characterized a novel index of steady-state respiratory chemoreflex drive (SSCD), accounting for integrated contributions from central and peripheral respiratory chemoreceptors during steady-state breathing at prevailing chemostimuli. Acetazolamide is often utilized during ascent for prevention or treatment of altitude-related illnesses, eliciting metabolic acidosis and stimulating respiratory chemoreceptors. To determine if SSCD reflects VA during ascent to HA, we characterized SSCD in 25 lowlanders during incremental ascent to 4240 m over 7 days. We subsequently compared two separate subgroups: no acetazolamide (NAz; n = 14) and those taking an oral prophylactic dose of acetazolamide (Az; 125 mg BID; n = 11). At 1130/1400 m (day zero) and 4240 m (day seven), steady-state measurements of resting ventilation (V̇ I ; L/min), pressure of end-tidal (P ET )CO 2 (Torr), and peripheral oxygen saturation (SpO 2 ; %) were measured. A stimulus index (SI; P ET CO 2 /SpO 2 ) was calculated, and SSCD was calculated by indexing V̇ I against SI. We found that (a) both V̇ I and SSCD increased with ascent to 4240 m (day seven; V̇ I : +39%, p < 0.0001, Hedges' g = 1.52; SSCD: +56.%, p < 0.0001, Hedges' g = 1.65), (b) and these responses were larger in the Az versus NAz subgroup (V̇ I : p = 0.02, Hedges' g = 1.04; SSCD: p = 0.02, Hedges' g = 1.05). The SSCD metric may have utility in assessing VA during prolonged stays at altitude, providing a feasible alternative to transient chemoreflex tests., (© 2022 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Hot springs are thought to be potential repositories for opportunistic infections, such as antibiotic-resistant strains. However, there is a scarcity of information on the mechanisms of antibiotic resistance gene (ARG) uptake, occurrence, and expression in thermophilic bacteria. Furthermore, because the genesis and proliferation of ARGs in environmental microorganisms are unknown, the research on antibiotic resistance profiles and probable mechanisms in thermophilic bacteria will become increasingly important. The goals of this study are to explore bacterial diversity, antibiotic and heavy metal resistance, and the prevalence and presence of ARG and metal resistance gene (MRG) in Geobacillus species. The 16S rRNA sequencing was used to determine the culturable bacterium diversity of 124 isolates. Standard Kirby Bauer Disc Diffusion and tube dilution procedures were used to determine antibiotic sensitivity and minimum inhibitory concentration (MIC). The tube dilution method was also used to check metal tolerance. To detect ARG and heavy MRG (HMRG), whole genome sequencing studies of the type species of the genus Geobacillus and five randomly selected Geobacillus species were performed. Graph Pad Prism and XLSTAT were used to perform statistical analyses such as ANOVA, EC50 analysis, and principal component analysis (PCA). The phylum Firmicutes and the genus Geobacillus dominated the culture-dependent bacterial diversity. Surprisingly, all thermophilic isolates, i.e., Geobacillus species, were sensitive to at least 10 different antibiotics, as evidenced by the lack of ARGs in whole genome sequencing analysis of numerous Geobacillus species. However, some of these isolates were resistant to at least five different heavy metals, and whole genome sequencing revealed the presence of MRGs in these thermophilic bacteria. The thermophilic genus Geobacillus is generally antibiotic sensitive, according to this study. In contrast, heavy metal is tolerated by them. As a result, it is possible that ARGs and MRGs do not coexist in these bacteria living in hot springs., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Najar, Das, Kumar, Sharma, Mondal, Sherpa and Thakur.)

Extreme ecosystems with enormous arrays of physicochemical or biological physiognomies serve as an important indicator of various processes occurred and/or occurring in and on the Earth. Among extreme habitats, hot springs represent geothermal features which are complex systems with a well-defined plumbing system. Besides geological tectonic based hypsography and orology annotations, the hot springs have served as hot spots for ages where there is an amalgamation of nature, religion, faith, health, and science. Thus, there remains an escalating scope to study these hot springs all over the world. The Himalayan Geothermal Belt (HGB) banquets three densely demographic countries i.e. Pakistan, India and China, that hosts numerous hot springs. Studies on the hot springs distributed over these countries reveal Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria as the predominant bacterial phyla. The bacterial diversity shows a significant positive correlation with physicochemical parameters like temperature, pH, Na + , HCO 3 - , etc. Physicochemical analyses of these hot springs indicate the water mainly as Na-Cl, Na-HCO 3 , SO 4 -Cl, and mixed type, with temperature ranging approximately between 100-250°C as predicted by various geothermometers. Numerous studies although done, not much of a comprehensive database of the analysis are provided on the hot springs harboured by the HGB. This review aims to give a cumulative illustration on comparative facets of various characteristic features of hot springs distributed over the HGB. These are found to be of great importance with respect to the exploitation of geothermal energy and microflora in various sectors of industries and biotechnology. They are also important sources in terms of socio-economic perspective, and routes to eco-medical tourism., Competing Interests: The authors declare that they have no competing interests., (© 2022 The Author(s).)

HAS2 is a member of the gene family encoding the hyaluronan synthase 2, which can generate high-molecular-weight hyaluronan (HMW-HA). Our previous study identified HAS2 as a candidate gene for increased susceptibility to adult asthma. However, whether HAS2 dysfunction affects airway remodeling and steroid insensitivity is still limited. Therefore, this study aimed to clarify the Has2 dysfunction, triggering severe airway remodeling and steroid insensitivity in a murine model of asthma. Has2 heterozygous-deficient ( Has2 +/- ) mice and their wild-type littermates have been evaluated in a model of chronic ovalbumin (OVA) sensitization and challenge. Mice present a higher sensitivity to OVA and higher IL-17 release as well as eosinophilic infiltration. RNA sequencing demonstrated the downregulation of EIF2 signaling pathways, TGF-β signaling pathways, and heat shock proteins with Th17 bias in Has2 +/- -OVA mice. The combined treatment with anti-IL-17A antibody and dexamethasone reduces steroid insensitivity in Has2 +/- -OVA mice. Has2 attenuation worsens eosinophilic airway inflammation, airway remodeling, and steroid insensitivity. These data highlight that HAS2 and HMW-HA are important for controlling intractable eosinophilic airway inflammation and remodeling and could potentially be exploited for their therapeutic benefits in patients with asthma., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Sherpa, Kiwamoto, Matsuyama, Tsunoda, Yazaki, Yoshida, Nakajima, Matsuno, Morishima, Ishii and Hizawa.)

Central sleep apnea (CSA) is characterized by periodic breathing (PB) during sleep, defined as intermittent periods of apnea/hypopnea and hyperventilation, with associated acute fluctuations in oxyhemoglobin saturation (SO 2 ). CSA has an incidence of ∼50% in heart failure patients but is universal at high altitude (HA; ≥2,500 m), increasing in severity with further ascent and/or time at altitude. However, whether PB is adaptive, maladaptive, or neutral with respect to sleeping SO 2 at altitude is unclear. We hypothesized that PB severity would improve mean sleeping SO 2 during acclimatization to HA due to relative, intermittent hyperventilation subsequent to each apnea. We utilized portable sleep monitors to assess the incidence and severity of CSA via apnea-hypopnea index (AHI) and oxygen desaturation index (ODI), and peripheral oxygen saturation ([Formula: see text]) during sleep during two ascent profiles to HA in native lowlanders: 1 ) rapid ascent to and residence at 3,800 m for 9 days/nights ( n = 21) and 2 ) incremental ascent to 5,160 m over 10 days/nights ( n = 21). In both ascent models, severity of AHI and ODI increased and mean sleeping [Formula: see text] decreased, as expected. However, during sleep on the last night/highest altitude of both ascent profiles, neither AHI nor ODI were correlated with mean sleeping [Formula: see text] . In addition, mean sleeping [Formula: see text] was not significantly different between high and low CSA. These data suggest that CSA is neither adaptive nor maladaptive with regard to mean oxygen saturation during sleep, owing to the relative hyperventilation between apneas, likely correcting transient apnea-mediated oxygen desaturation and maintaining mean oxygenation. NEW & NOTEWORTHY Central sleep apnea (CSA) is universal during ascent to high altitude, with intermittent and transient fluctuations in oxygen saturation, but the consequences on mean sleeping blood oxygenation are unclear. We assessed indices of CSA and mean sleeping peripheral oxygen saturation ([Formula: see text]) during ascent to high altitude using two ascent profiles: rapid ascent and residence at 3,800 m and incremental ascent to 5,160 m. The severity of CSA was not correlated with mean sleeping [Formula: see text] with ascent.

Organic farming is an eco-friendly and sustainable farming practice that enhances soil fertility and helps in improving soil quality. But with the commencement of more sophisticated advances in agricultural techniques, organic farming has gradually become limited in the world. Culture-dependent plant growth-promoting bacterial isolates were isolated from the bulk and rhizospheric soil, of the native high yielding pole type organic pea ( Pisum sativum L.) cultivar Dentami of Dentam, West Sikkim, India. Based on the 16S rRNA gene sequencing identification of these isolates, it was found that from the bulk soil, Actinobacteria (58%) was the dominant phyla followed by Firmicutes (28%), and Proteobacteria (14%). In the rhizospheric soil it was dominated by Proteobacteria (56%), followed by Firmicutes (33%), and Bacteriodetes (11%). A total of 40 bacterial isolates were initially screened for the plant growth-promoting (PGP) activity and out of them only four bacterial isolates i.e., Bacillus cereus P8, Arthrobacter woluwensi s DP2, Paenarthrobacter nitroguajacolicus PP3, and Bacillus mycoides PP10 with accession numbers MN589697, MN559516, MN519462 and MN589696 respectively were found to possess higher PGP activity (i.e. phosphorous, potassium solubilization and nitrogen-fixing activity) as compared to the other bacteria present in the soil. Based on the indole-3-acetic acid (IAA) quantitative assay and siderophore production assay, it was found that Bacillus cereus (MN589697) produced the highest IAA (65.5 µg mL -1 ) and siderophore (71%) when compared with the other isolates. The statistical correlation suggests that pH and available phosphorus were the strongest influencing factors for the distribution of Proteobacteria in the rhizospheric soil. The results indicate that these isolates can be potential plant growth promoter under the agro-climatic conditions of Sikkim, India. To the best of our knowledge the present study is the first report of its kind and showcases significant findings pertaining to the assessment of diversity, isolation and identification of plant growth-promoting rhizobacteria of organic pea grown in Sikkim., Competing Interests: The authors declare no conflict of interest., (© 2021 The Author(s). Published by Elsevier B.V.)

The programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) pathway could affect antimicrobial immune responses by suppressing T cell activity. Several recent studies demonstrated that blocking of the PD-1/PD-L1 pathway exacerbated Mycobacterium tuberculosis infection. However, the effect of blocking this pathway in pulmonary Mycobacterium avium-intracellulare complex (MAC) infection is not fully understood. Wild-type, PD-1-deficient mice, and PD-L1-deficient mice were intranasally infected with Mycobacterium avium bacteria. Depletion of PD-1 or PD-L1 did not affect mortality and bacterial burden in MAC-infected mice. However, marked infiltration of CD8-positive T lymphocytes was observed in the lungs of PD-1 and PD-L1-deficient mice compared to wild-type mice. Comprehensive transcriptome analysis showed that levels of gene expressions related to Th1 immunity did not differ according to the genotypes. However, genes related to the activity of CD8-positive T cells and related chemokine activity were upregulated in the infected lungs of PD-1 and PD-L1-deficient mice. Thus, the lack of change in susceptibility to MAC infection in PD-1 and PD-L1-deficient mice might be explained by the absence of obvious changes in the Th1 immune response. Furthermore, activated CD8-positive cells in response to MAC infection in these mice seemed to not be relevant in the control of MAC infection., (© 2021. The Author(s).)

Eight rhizospheric bacteria were isolated from the organic paddy fields of Sikkim, India, and identified as Pseudomonas kribbensis KSB, Burkholderia cenocepacia SRD, Kosakonia oryzendophytica YMA7, Pseudomonas rhodesiae SRB, Bacillus sp. ARA, Paenibacillus polymyxa COW3, Bacillus aryabhattai PSB2, and Bacillus megaterium PSB1. They showed plant growth-promoting attributes in rice and have bio-control potential against phytopathogen Colletotrichum gloeosporioides of large cardamom ( Amomum subulatum ). Burkholderia cenocepacia SRD showed production of indole acetic acid and ammonia and solubilization of phosphate and potassium and also possessed nitrogen fixation potential. It showed antagonistic activity against two other plant pathogens of large cardamom, viz., Curvularia eragrostidis and Pestalotiopsis sp., under in vitro conditions. The liquid bacterial consortium was prepared using the bacterial strains SRB, PSB1, and COW3 (Consortia-1); PSB2, SRD, and COW3 (Consortia-2); and COW3, KSB, and YMA7 (Consortia-3) to increase the growth and yield of rice plants under organic farming conditions. Greenhouse and field studies showed that the Consortia-3 had the highest plant growth-promoting activity. Consortia-3 demonstrated better agronomic performance in terms of root length (9.5 cm),number of leaflets per plant (5.3), grains per panicle (110.6), test grain weight (27.4 g), dry root weight per plant (0.73 g), and total dry biomass per plant (8.26 g)., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Sherpa, Sharma, Bag and Das.)

Fungi are considered to be the most resilient and economically important microbial community that can easily survive and optimally grow under a wide range of growth conditions. Thermophilic fungi from the geothermal sources have been less pondered upon and lie unexplored. Here, a microbiome approach was conducted to understand the concealed world of the environmental mycobiota from the two hot springs of North Sikkim district located in North-east India. The solfataric muds from the hot springs were analyzed. In both the samples, on the basis of genus level classification, genus Fusarium had the highest abundance followed by Colletotrichum, Pochonia, Pyricularia, Neurospora, etc. Analyzing the predicted genes, the functional proteins of New Yume Samdung mycobiome were found to be dominated by the genera Fusarium (22%), Trichoderma (12%), and Aspergillus (11%), whereas in the case of Old Yume Samdung, it was dominated by the genera Aspergillus (11%), Saccharomyces (6%), and Fusarium (5%). Interestingly, in the studied mycobiome, environmental yeasts were also detected. From the functional metagenomics, sulfate adenylatetransferase (SAT) proteins for sulfur assimilation were found in some of the fungal reads. Toxin protein reads such as AM-toxin biosynthesis proteins, AF-toxin biosynthesis proteins, Gliotoxin biosynthesis proteins, and aflatoxin biosynthesis proteins were detected in the mycobiomes.

New Findings: What is the central question of this study? What is the relative contribution of a putative tonic splenic contraction to the haematological acclimatization process during high altitude ascent in native lowlanders? What is the main finding and its importance? Spleen volume decreased by -14.3% (-15.2 ml) per 1000 m ascent, with an attenuated apnoea-induced [Hb] increase, attesting to a tonic splenic contraction during high altitude ascent. The [Hb]-enhancing function of splenic contraction may contribute to restoring oxygen content early in the acclimatization process at high altitude., Abstract: Voluntary apnoea causes splenic contraction and reductions in heart rate (HR; bradycardia), and subsequent transient increases in haemoglobin concentration ([Hb]). Ascent to high altitude (HA) induces systemic hypoxia and reductions in oxygen saturation ( S p O 2 ), which may cause tonic splenic contraction, which may contribute to haematological acclimatization associated with HA ascent. We measured resting cardiorespiratory variables (HR, S p O 2 , [Hb]) and resting splenic volume (via ultrasound) during incremental ascent from 1400 m (day 0) to 3440 m (day 3), 4240 m (day 7) and 5160 m (day 10) in non-acclimatized native lowlanders during assent to HA in the Nepal Himalaya. In addition, apnoea-induced responses in HR, S p O 2 and splenic volume were measured before and after two separate voluntary maximal apnoeas (A1-A2) at 1400, 3440 and 4240 m. Resting spleen volume decreased -14.3% (-15.2 ml) per 1000 m with ascent, from 140 ± 41 ml (1400 m) to 108 ± 28 ml (3440 m; P > 0.99), 94 ± 22 ml (4240 m; P = 0.009) and 84 ± 28 ml (5160 m; P = 0.029), with concomitant increases in [Hb] from 125 ± 18.3 g l -1 (1400 m) to 128 ± 10.4 g l -1 (3440 m), 138.8 ± 12.7 g l -1 (4240 m) and 157.5 ± 8 g l -1 (5160 m; P = 0.021). Apnoea-induced splenic contraction was 50 ± 15 ml (1400 m), 44 ± 17 ml (3440 m; P > 0.99) and 26 ± 8 ml (4240 m; P = 0.002), but was not consistently associated with increases in [Hb]. The apnoea-induced bradycardia was more pronounced at 3440 m (A1: P = 0.04; A2: P = 0.094) and at 4240 m (A1: P = 0.037 A2: P = 0.006) compared to values at 1400 m. We conclude that hypoxia-induced splenic contraction at rest (a) may contribute to restoring arterial oxygen content through its [Hb]-enhancing contractile function and (b) eliminates further apnoea-induced [Hb] increases in hypoxia. We suggest that tonic splenic contraction may contribute to haematological acclimatization early in HA ascent in humans., (© 2020 The Authors. Experimental Physiology © 2020 The Physiological Society.)

New Findings: What is the central question of this study? We assessed the utility of a new metric for quantifying ventilatory acclimatization to high altitude, derived from differential ascent and descent steady-state cardiorespiratory variables (i.e. hysteresis). Furthermore, we aimed to investigate whether the magnitude of cardiorespiratory hysteresis was associated with the development of acute mountain sickness. What is the main finding and its importance? Hysteresis in steady-state cardiorespiratory variables quantifies ventilatory acclimatization to high altitude. The magnitude of cardiorespiratory hysteresis during ascent to and descent from high altitude was significantly related to the development of symptoms of acute mountain sickness. Hysteresis in steady-state chemoreflex drive can provide a simple, non-invasive method of tracking ventilatory acclimatization to high altitude., Abstract: Maintenance of arterial blood gases is achieved through sophisticated regulation of ventilation, mediated by central and peripheral chemoreflexes. Respiratory chemoreflexes are important during exposure to high altitude owing to the competing influence of hypoxia and hypoxic hyperventilation-mediated hypocapnia on steady-state ventilatory drive. Inter-individual variability exists in ventilatory acclimatization to high altitude, potentially affecting the development of acute mountain sickness (AMS). We aimed to quantify ventilatory acclimatization to high altitude by comparing differential ascent and descent values (i.e. hysteresis) in steady-state cardiorespiratory variables. We hypothesized that: (i) the hysteresis area formed by cardiorespiratory variables during ascent and descent would quantify the magnitude of ventilatory acclimatization; and (ii) larger hysteresis areas would be associated with lower AMS symptom scores during ascent. In 25 healthy, acetazolamide-free trekkers ascending to and descending from 5160 m, cardiorespiratory hysteresis was measured in the partial pressure of end-tidal CO 2 , peripheral oxygen saturation, minute ventilation, chemoreceptor stimulus index (end-tidal CO 2 /peripheral oxygen saturation) and the calculated steady-state chemoreflex drive (SS-CD; minute ventilation/chemoreceptor stimulus index) using portable devices (capnograph, peripheral pulse oximeter and respirometer, respectively). Symptoms of AMS were assessed daily using the Lake Louise questionnaire. We found that: (i) ascent-descent hysteresis was present in all cardiorespiratory variables; (ii) SS-CD is a valid metric for tracking ventilatory acclimatization to high altitude; and (iii) the highest AMS scores during ascent exhibited a significant, moderate and inverse correlation with the magnitude of SS-CD hysteresis (r s  = -0.408, P = 0.043). We propose that ascent-descent hysteresis is a new and feasible way to quantify ventilatory acclimatization in trekkers during high-altitude exposure., (© 2020 The Authors. Experimental Physiology © 2020 The Physiological Society.)

Changme Khangpu glacier is located in the northern district of Sikkim which comes under UNESCO heritage site Kanchenjunga Biosphere Reserve which is considered as one of the important biological hotspot regions in the Eastern Himalayas. This is the first report on microbial diversity analysis of moraine soil from one of the unexplored glaciers of Sikkim using high throughput sequencing platform and phospholipid fatty acids analysis (PLFA). It was found that the 16S amplicon sequence comprised 362,902 raw sequences with a sequence length of 150 bp and (G + C) content 52%. A total of 156,821 pre-processed reads were clustered into 378 OTUs (operational taxonomic units) comprising 6 bacterial phyla. The top four dominant phyla based on the 16S amplicon sequences were Proteobacteria (56%), Firmicutes (16%), Actinobacteria (12%), and Bacteroidetes (8%), respectively. PLFA analysis confirmed the dominance of Gram positive bacteria (72%) followed by Gram negative bacteria (32%) and the major fatty acids which are present in the moraine soil sample were PUFA (61%), and 18:2ω6,9c (29%). This is the primary study and first of its kind done on moraine soil from glaciers of Sikkim. Based on 16S amplicon sequencing and PLFA analysis of moraine soil samples from glaciers of Sikkim suggest that this glaciers harbours rich microbial diversity and thus can have wide industrial and biotechnological potential. Thus, there is an escalating scope to further study these extreme biomes with respect to their microbial diversity and their functional capabilities.

Sherpa, Mingma Thsering, and Raksha Shrestha. Stroke at high altitude in an experienced Sherpa climber: A case report. High Alt Med Biol . 21:406-408, 2020.-A 44-year-old experienced Sherpa climber had dizziness with nausea and several episodes of vomiting while at Camp 2 of Mount Everest (6400 m). He was airlifted from Everest Base Camp to Kathmandu for further treatment. Neurological assessment revealed cerebellar signs with ataxia. Sensory examination revealed hypoesthesia on the extremities of the left side and right half of the face. Laboratory workup revealed increased hemoglobin and hematocrit levels. Magnetic resonance imaging of brain revealed ischemic infarction of right cerebellar hemisphere in the right posterior inferior cerebellar artery territory extending to medulla. Patient was managed with aspirin, supportive measures, and physiotherapy, and made a complete recovery after 2 months. This is the first documented case of ischemic stroke in a healthy experienced Sherpa climber. Although the exact cause of stroke in our patient remains uncertain, the prothrombotic state due to high altitude compounded by impaired cerebral autoregulation and dehydration may have been contributory factors.

Stenotrophomonas maltophilia strain P13 was isolated from the Kanchengayao glacier's accumulation zone. A comprehensive study was done on this strain as it produced protease enzyme and thus having industrial potential. The whole genome sequence, FAME, morphological and biochemical characteristics of the S. maltophilia strain P13 is being presented. The genome of P13 strain possesses 2,689,565 total reads, with an average G  +  C content of 69.9%. The whole-genome assembly is having 548 contigs (with PEGs). The genome contains 2,985 coding sequences with 55 rRNA predicted genes. More than 88% of the total pre-processed reads from samples were mapped. The identified coding proteins were classified into 27 functional categories based on COG classification. The genome was found to possess genes for ammonium assimilation, galactosylceramide and sulfatide metabolism. The major enzymes present are beta-galactosidase, thiol peroxidase, thiolredoxin reductase, glutamate synthase, and glutamate-ammonia-ligase adenyltransferase. The genome information of Stenotrophomonas maltophilia P13 provides the basis for understanding the functional properties and abilities to act as a potential cold-active enzyme producer and nitrogen-fixing bacteria., Competing Interests: None to be declared., (© 2020 The Author(s).)

Glacier studies as of late have ruffled many eyeballs, exploring this frigid ecology to understand the impact of climate change. Mapquesting the glaciers led to the discovery of concealed world of "psychrophiles" harboring in it. In the present study, the antibiotic resistance genes (ARGs) and heavy metal resistance genes (MRGs) were evaluated through both the culture-dependent and culture-independent methods. Samples were collected from two different glaciers, i.e., debris-covered glacier (Changme Khangpu) and debris-free glacier (Changme Khang). Functional metagenomics of both the glacier samples, provided evidence of presence of resistant genes against various antibiotic groups. Bacitracin resistant gene (bacA) was the predominant ARG in both the glaciers. MRGs in both the glacier samples were diversified as the genes detected were resistant against various heavy metals such as arsenic, tungsten, mercury, zinc, chromium, copper, cobalt, and iron. Unique MRGs identified from Changme Khangpu glacier were resistant to copper (cutA, cutE, cutC, cutF, cueR, copC, and copB) and chromium (yelf, ruvB, nfsA, chrR, and chrA) whereas, from Changme Khang glacier they showed resistance against cobalt (mgtA, dmef, corD, corC, corB, and cnrA), and iron (yefD, yefC, yefB, and yefA) heavy metals. ARGs aligned maximum identity with Gram-negative psychrotolerant bacteria. The cultured bacterial isolates showed tolerance to high concentrations of tested heavy metal solutions. Interestingly, some of the antibiotic resistant bacterial isolates also showed tolerance towards the higher concentrations of heavy metals. Thus, an introspection of the hypothesis of co-occurrence and/co-selection of ARGs and MRGs in such environments has been highlighted here., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Sikkim is one of the bio-diverse states of India, which harbors diverse alkaline and sulfur rich hot springs in its vicinity. However, there is a dearth of data present in terms of microbial and its functional diversity as only a few hot springs have been studied in this area. Thus, in this regard, microbial and functional diversity of two hot springs by NGS, PLFA, and culture-independent approaches were carried out. PLFA and culture-dependent analysis was complementary as the Gram-positive bacteria were abundant in both the hot springs with the dominance of phylum Firmicutes with Geobacillus. Metagenomic analysis revealed the abundance of Proteobacteria, Actinobacteria, and Firmicutes in both hot springs. Functional metagenomics suggested that both Yumthang and Reshi hot spring possess a diverse set of genes analogous to stress such as genes allied to osmotic, heat shock, and acid stresses; defense analogies such as multidrug resistance efflux pump, multidrug transport system, and β-lactamase; and CRISPR analogues such as related to Cas1, Cas2, Cas3, cmr1-5 proteins, CT1972, and CT1133 gene families. The xenobiotic analogues were found against benzoate, nitrotolune, xylene, DDT, and chlorocyclohexane/chlorobenzene degradation. Thus, these defensive mechanisms against environmental and anthropogenic hiccups and hindrances provide the eco-efficiency to such thermal habitats. The higher enzymatic, degradation, defense, stress potential and the lower percentage identity (< 95%) of isolates encourage the further exploration and exploitation of these habitats for industrial and biotechnological purposes.

Objectives: Mechanisms of occurrence and expression of antibiotic resistance genes (ARGs) in thermophilic bacteria are still unknown owing to limited research and data. In this research, comparative profiling of ARGs and metal tolerance genes among thermophilic bacteria has been done by functional metagenomic methods., Methods: Shotgun metagenomic sequence data were generated using Illumina HiSeq 4000. Putative ARGs from the PROKKA predicted genes were identified with the ardbAnno V.1.0 script available from the ARDB (Antibiotic Resistance Genes Database) consortium using the non-redundant resistance genes as a reference. Putative metal resistance genes (MRGs) were identified by using BacMetScan V.1.0. The whole-genome sequencing for bacterial isolates was performed using Illumina HiSeq 4000 sequencing technology with a paired-end sequencing module., Results: Metagenomic analysis showed the dominance of Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes in two hot springs of Sikkim. ARG analysis through shotgun gene sequencing was found to be negative in the case of thermophilic bacteria. However, few genes were detected but they showed maximum similarity with mesophilic bacteria. Concurrently, MRGs were also detected in the metagenome sequence of isolates from hot springs. Detection of MRGs and absence of ARGs investigated by whole-genome sequencing in the reference genome sequence of thermophilic Geobacillus also conveyed the same message., Conclusion: The study of ARGs and MRGs (Heavy metal resistance gene) among culturable and non-culturable bacteria from the hot springs of Sikkim via metagenomics showed a preferential selection of MRGs over ARGs. The absence of ARGs also does not support the co-selection of ARGs and MRGs in these environments. This evolutionary selection of metal resistance over antibiotic genes may have been necessary to survive in the geological craters which have an abundance of different metals from earth sediments rather than antibiotics. Furthermore, the selection could be environment driven depending on the susceptibility of ARGs in a thermophilic environments as it reduces the chances of horizontal gene transfer., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Viruses are the most prodigious repertory of the genetic material on the earth. They are elusive, breakneck, evolutionary life particles that constitute a riveting concealed world. Environmental viruses have been obscurely explored, and hence, such an intriguing world of viruses was studied in the Himalayan Geothermal Belt of Indian peninsula at Sikkim corridor through hot springs. The hot springs located at the North Sikkim district were selected for the current study. The solfataric mud sediment samples were pooled from both the hot springs. The virus community showed significant diversity among the two hot springs of Yume Samdung. Reads for viruses among the mud sediments at Old Yume Samdung hot springs (OYS) was observed to be 11% and in the case of New Yume Samdung hot springs (NYS) it was 6%. Both the hot springs were abundant in dsDNA viromes. The metavirome reads in both the OYS and NYS hot spring mud sediments showed the predominance of Caudovirales; Herpesvirales; Ortervirales among which viral reads from Siphoviridae, Myoviridae, Phycodnaviridae and Podoviridae were abundantly present. Other viral communities belonged to families like Baculoviridae, Mimiviridae, Parvoviridae, Marseilleviridae etc. Interestingly, in the case of NYS, the unassigned group reads belonged to some unclassified giant DNA viruses like genera Pandoravirus and Pithovirus . Other interesting findings were - reads for Badnavirus having ds (RT-DNA) was exclusively found in NYS whereas Rubulavirus having ss(-)RNA was exclusively found in OYS sample. This is the first ever report on viruses from any hot springs of Sikkim till date., Competing Interests: None to be declared., (© 2020 The Author(s).)

High-altitude ascent imposes a unique cerebrovascular challenge due to two opposing blood gas chemostimuli. Specifically, hypoxia causes cerebral vasodilation, whereas respiratory-induced hypocapnia causes vasoconstriction. The conflicting nature of these two superimposed chemostimuli presents a challenge in quantifying cerebrovascular reactivity (CVR) in chronic hypoxia. During incremental ascent to 4240 m over 7 days in the Nepal Himalaya, we aimed to (a) characterize the relationship between arterial blood gas stimuli and anterior, posterior and global (g)CBF, (b) develop a novel index to quantify cerebral blood flow (CBF) in relation to conflicting steady-state chemostimuli, and (c) assess these relationships with cerebral oxygenation (rSO 2 ). On rest days during ascent, participants underwent supine resting measures at 1045 m (baseline), 3440 m (day 3) and 4240 m (day 7). These measures included pressure of arterial (Pa)CO 2 , PaO 2 , arterial O 2 saturation (SaO 2 ; arterial blood draws), unilateral anterior, posterior and gCBF (duplex ultrasound; internal carotid artery [ICA] and vertebral artery [VA], gCBF [{ICA + VA} × 2], respectively) and rSO 2 (near-infrared spectroscopy). We developed a novel stimulus index (SI), taking into account both chemostimuli (PaCO 2 /SaO 2 ). Subsequently, CBF was indexed against the SI to assess steady-state cerebrovascular responsiveness (SS-CVR). When both competing chemostimuli are taken into account, (a) SS-CVR was significantly higher in ICA, VA and gCBF at 4240 m compared to lower altitudes, (b) delta SS-CVR with ascent (1045 m vs. 4240 m) was higher in ICA vs. VA, suggesting regional differences in CBF regulation, and (c) ICA SS-CVR was strongly and positively correlated (r = 0.79) with rSO 2 at 4240 m.

Swallow and breathing are highly coordinated behaviors reliant on shared anatomical space and neural pathways. Incremental ascent to high altitudes results in hypoxia/hypocapnic conditions altering respiratory drive, however it is not known whether these changes also alter swallow. We examined the effect of incremental ascent (1045 m, 3440 m and 4371 m) on swallow motor pattern and swallow-breathing coordination in seven healthy adults. Submental surface electromyograms (sEMG) and spirometry were used to evaluate swallow triggered by saliva and water infusion. Swallow-breathing phase preference was different between swallows initiated by saliva versus water. With ascent, saliva swallows changed to a dominate pattern of occurrence during the transition from inspiration to expiration. Additionally, water swallows demonstrated a significant decrease in submental sEMG duration and a shift in submental activity to earlier in the apnea period, especially at 4371 m. Our results suggest that there are changes in swallow-breathing coordination and swallow production that likely increase airway protection with incremental ascent to high altitude. The adaptive changes in swallow were likely due to the exposure to hypoxia and hypocapnia, along with airway irritation., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Sonographic B-lines can indicate pulmonary interstitial edema. We sought to determine the incidence of subclinical pulmonary edema measured by sonographic B-lines among lowland trekkers ascending to high altitude in the Nepal Himalaya. Twenty healthy trekkers underwent portable sonographic examinations and arterial blood draws during ascent to 5160 m over ten days. B-lines were identified in twelve participants and more frequent at 4240 m and 5160 m compared to lower altitudes (P < 0.03). There was a strong negative correlation between arterial oxygen saturation and the number of B-lines at 5160 m (ρ = -0.75, P = 0.008). Our study contributes to the growing body of literature demonstrating the development of asymptomatic pulmonary edema during ascent to high altitude. Portable lung sonography may have utility in fieldwork contexts such as trekking at altitude, but further research is needed in order to clarify its potential clinical applicability., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Key Points: Ascent to high altitude imposes an acid-base challenge in which renal compensation is integral for maintaining pH homeostasis, facilitating acclimatization and helping prevent mountain sicknesses. The time-course and extent of plasticity of this important renal response during incremental ascent to altitude is unclear. We created a novel index that accurately quantifies renal acid-base compensation, which may have laboratory, fieldwork and clinical applications. Using this index, we found that renal compensation increased and plateaued after 5 days of incremental altitude exposure, suggesting plasticity in renal acid-base compensation mechanisms. The time-course and extent of plasticity in renal responsiveness may predict severity of altitude illness or acclimatization at higher or more prolonged stays at altitude., Abstract: Ascent to high altitude, and the associated hypoxic ventilatory response, imposes an acid-base challenge, namely chronic hypocapnia and respiratory alkalosis. The kidneys impart a relative compensatory metabolic acidosis through the elimination of bicarbonate (HCO 3 - ) in urine. The time-course and extent of plasticity of the renal response during incremental ascent is unclear. We developed an index of renal reactivity (RR), indexing the relative change in arterial bicarbonate concentration ([HCO 3 - ] a ) (i.e. renal response) against the relative change in arterial pressure of CO 2 ( P aC O 2 ) (i.e. renal stimulus) during incremental ascent to altitude ( Δ [ HC O 3 - ] a / Δ P aC O 2 ). We aimed to assess whether: (i) RR magnitude was inversely correlated with relative changes in arterial pH (ΔpH a ) with ascent and (ii) RR increased over time and altitude exposure (i.e. plasticity). During ascent to 5160 m over 10 days in the Nepal Himalaya, arterial blood was drawn from the radial artery for measurement of blood gas/acid-base variables in lowlanders at 1045/1400 m and after 1 night of sleep at 3440 m (day 3), 3820 m (day 5), 4240 m (day 7) and 5160 m (day 10) during ascent. At 3820 m and higher, RR significantly increased and plateaued compared to 3440 m (P < 0.04), suggesting plasticity in renal acid-base compensations. At all altitudes, we observed a strong negative correlation (r ≤ -0.71; P < 0.001) between RR and ΔpH a from baseline. Renal compensation plateaued after 5 days of altitude exposure, despite subsequent exposure to higher altitudes. The time-course, extent of plasticity and plateau in renal responsiveness may predict severity of altitude illness or acclimatization at higher or more prolonged stays at altitude., (© 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.)

The Himalayas are water tower for billions of people; however in recent years due to climate change several glaciers of Himalaya are receding or getting extinct which can lead to water scarcity and political tensions. Thus, it requires immediate attention and necessary evaluation of all the environmental parameters which can lead to conservation of Himalayan glaciers. This study is the first attempt to investigate the bacterial diversity from debris-free Changme Khang (CKG) and debris-cover Changme Khangpu (CK) glacier, North Sikkim, India. The abundance of culturable bacteria in CKG glaciers was 1.5 × 10 4  cells/mL and CK glacier 1.5 × 10 5  cells/mL. A total of 50 isolates were isolated from both the glacier under aerobic growth condition. The majority of the isolates from both the glaciers were psychrotolerant according to their growth temperature. Optimum growth temperatures of the isolates were between 15 and 20 °C, pH 6-8 and NaCl 0-2%. The phylogenetic studies of 16S RNA gene sequence suggest that, these 21 isolates can be assigned within four phyla/class, i.e., Firmicutes, Beta-proteobacteria, Gamma-proteobacteria and Actinobacteria. The dominant phyla were Firmicutes 71.42% followed by Actinobacteria 14.28%, Alpha-proteobacteria 9.52% and Beta-proteobacteria 4.76%. The isolate Bacillus thuringiensis strain CKG2 showed the highest protease activity (2.24 unit/mL/min). Considering the fast rate at which Himalayan glaciers are melting and availability of limited number of research, there is urgent need to study the microbial communities confined in such environments., Competing Interests: Compliance with Ethical StandardsAuthors have no conflict of Interests.

Neurovascular coupling (NVC) is the temporal link between neuronal metabolic activity and regional cerebral blood flow (CBF), supporting adequate delivery of nutrients. Exposure to high altitude (HA) imposes several stressors, including hypoxia and hypocapnia, which modulate cerebrovascular tone in an antagonistic fashion. Whether these contrasting stressors and subsequent adaptations affect NVC during incremental ascent to HA is unclear. The aim of this study was to assess whether incremental ascent to HA influences the NVC response. Given that CBF is sensitive to changes in arterial blood gasses, in particular PaCO 2 , we hypothesized that the vasoconstrictive effect of hypocapnia during ascent would decrease the NVC response. 10 healthy study participants (21.7 ± 1.3 years, 23.57 ± 2.00 kg/m 2 , mean ± SD) were recruited as part of a research expedition to HA in the Nepal Himalaya. Resting posterior cerebral artery velocity (PCAv), arterial blood gasses (PaO 2 , SaO 2 , PaCO 2 , [HCO 3 - ], base excess and arterial blood pH) and NVC response of the PCA were measured at four pre-determined locations: Calgary/Kathmandu (1045/1400 m, control), Namche (3440 m), Deboche (3820 m) and Pheriche (4240 m). PCAv was measured using transcranial Doppler ultrasound. Arterial blood draws were taken from the radial artery and analyzed using a portable blood gas/electrolyte analyzer. NVC was determined in response to visual stimulation (VS; Strobe light; 6 Hz; 30 s on/off × 3 trials). The NVC response was averaged across three VS trials at each location. PaO 2 , SaO 2 , and PaCO 2 were each significantly decreased at 3440, 3820, and 4240 m. No significant differences were found for pH at HA ( P > 0.05) due to significant reductions in [HCO 3 - ] ( P < 0.043). As expected, incremental ascent to HA induced a state of hypoxic hypocapnia, whereas normal arterial pH was maintained due to renal compensation. NVC was quantified as the delta (Δ) PCAv from baseline for mean PCAv, peak PCAv and total area under the curve (ΔPCAv tAUC) during VS. No significant differences were found for Δmean, Δpeak or ΔPCAv tAUC between locations ( P > 0.05). NVC remains remarkably intact during incremental ascent to HA in healthy acclimatized individuals. Despite the array of superimposed stressors associated with ascent to HA, CBF and NVC regulation may be preserved coincident with arterial pH maintenance during acclimatization.

A thermophilic, spore-forming, rod-shaped bacterium isolated from the Yumthang hot spring in North Sikkim, India was subjected to taxonomic studies. The thermophilic bacterial isolate was designated as strain AYN2 T . Cells were Gram-stain-positive, aerobic, motile, rod-shaped, catalase-positive and methyl red-negative. Strain AYN2 T was able to grow in the pH range from 6 to 10 (optimum, pH 7.5-8.0), at 40-70 °C (60 °C) and in NaCl concentrations of 0-4 % (1 %). The major cellular fatty acids were iso-C15 : 0 (12.8 %), iso-C16 : 0 (13.9 %) and iso-C17 : 0 (13.8 %). No matches were found in the rtsba6 Sherlock libraries. The G+C content of the genomic DNA was 42.11 mol%. Based on phylogenetic analysis of the 16S rRNA gene sequences, strain AYN T showed highest sequence similarity to the type strain of Geobacillus toebii (96 %). However, the phenotypic properties of strain AYN2 T were clearly distinct from those of G. toebii and related species. On the basis of polyphasic analysis, strain AYN2 T represents a novel species in the genus Geobacillus, for which the name Geobacillus yumthangensis sp. nov. is proposed. The type strain is AYN2 T (MTCC=12749=KCTC=33950= JCM 32596).

Northeastern regions of India are known for their floral and faunal biodiversity. Especially the state of Sikkim lies in the eastern Himalayan ecological hotspot region. The state harbors many sulfur rich hot springs which have therapeutic and spiritual values. However, these hot springs are yet to be explored for their microbial ecology. The development of neo generation techniques such as metagenomics has provided an opportunity for inclusive study of microbial community of different environment. The present study describes the microbial diversity in two hot springs of Sikkim that is Polok and Borong with the assist of culture dependent and culture independent approaches. The culture independent techniques used in this study were next generation sequencing (NGS) and Phospholipid Fatty Acid Analysis (PLFA). Having relatively distinct geochemistry both the hot springs are thermophilic environments with the temperature range of 50-77 °C and pH range of 5-8. Metagenomic data revealed the dominance of bacteria over archaea. The most abundant phyla were Proteobacteria and Bacteroidetes although other phyla were also present such as Acidobacteria, Nitrospirae, Firmicutes, Proteobacteria, Parcubacteria and Spirochaetes. The PLFA studies have shown the abundance of Gram Positive bacteria followed by Gram negative bacteria. The culture dependent technique was correlative with PLFA studies. Most abundant bacteria as isolated and identified were Gram-positive genus Geobacillus and Anoxybacillus. The genus Geobacillus has been reported for the first time in North-Eastern states of India. The Geobacillus species obtained from the concerned hot springs were Geobacillus toebii, Geobacillus lituanicus, Geobacillus Kaustophillus and the Anoxybacillus species includes Anoxybacillus gonensis and Anoxybacillus Caldiproteolyticus. The distribution of major genera and their statistical correlation analyses with the geochemistry of the springs predicted that the temperature, pH, alkalinity, Ca 2+ , Mg 2+ , Cl 2+ , and sulfur were main environmental variables influencing the microbial community composition and diversity. Also the piper diagram suggested that the water of both the hot springs are Ca-HCO 3- type and can be predicted as shallow fresh ground waters. This study has provided an insight into the ecological interaction of the diverse microbial communities and associated physicochemical parameters, which will help in determining the future studies on different biogeochemical pathways in these hot springs., (Copyright © 2018. Published by Elsevier B.V.)

High-altitude natives employ numerous physiological strategies to survive and reproduce. However, the concomitant influence of altitude and physical activity during pregnancy has not been studied above 3,700 m. We report a case of physical activity, sleep behavior, and physiological measurements on a 28-yr-old third-trimester pregnant native highlander (Sherpa) during ascent from 3,440 m to Everest Base Camp (~5,300 m) over 8 days in the Nepal Himalaya and again ~10 mo postpartum during a similar ascent profile. The participant engaged in 250-300 min of moderate to vigorous physical activity per day during ascent to altitude while pregnant, with similar volumes of moderate to vigorous physical activity while postpartum. There were no apparent maternal, fetal, or neonatal complications related to the superimposition of the large volumes of physical activity at altitude. This report demonstrates a rare description of physical activity and ascent to high altitude during pregnancy and points to novel questions regarding the superimposition of pregnancy, altitude, and physical activity in high-altitude natives.

Measurements of central and peripheral respiratory chemoreflexes are important in the context of high altitude as indices of ventilatory acclimatization. However, respiratory chemoreflex tests have many caveats in the field, including considerations of safety, portability and consistency. This overview will (a) outline commonly utilized tests of the hypoxic ventilatory response (HVR) in humans, (b) outline the caveats associated with a variety of peak response HVR tests in the laboratory and in high altitude fieldwork contexts, and (c) advance a novel index of steady-state chemoreflex drive (SS-CD) that addresses the many limitations of other chemoreflex tests. The SS-CD takes into account the contribution of central and peripheral respiratory chemoreceptors, and eliminates the need for complex equipment and transient respiratory gas perturbation tests. To quantify the SS-CD, steady-state measurements of the pressure of end-tidal (P ET )CO 2 (Torr) and peripheral oxygen saturation (SpO 2 ; %) are used to quantify a stimulus index (SI; P ET CO 2 /SpO 2 ). The SS-CD is then calculated by indexing resting ventilation (L/min) against the SI. SS-CD data are subsequently reported from 13 participants during incremental ascent to high altitude (5160 m) in the Nepal Himalaya. The mean SS-CD magnitude increased approximately 96% over 10 days of incremental exposure to hypobaric hypoxia, suggesting that the SS-CD tracks ventilatory acclimatization. This novel SS-CD may have future utility in fieldwork studies assessing ventilatory acclimatization during incremental or prolonged stays at altitude, and may replace the use of complex and potentially confounded transient peak response tests of the HVR in humans.

Myiasis occurs in humans and vertebrate animals mostly due to dipterous flies of the genera Chrysomyia and Cochliomyia. There have been reported cases of myiasis of skin, breast, intestine, eyes and ear but very few cases of vulvar myiasis have been reported in the medical literature. We report a case of a 20 years old female with vulvar myiasis. A 20-year old unmarried girl presented to our hospital with complains of vaginal discharge and vulvar irritation for 3 days with evidence of some worms around her vulvar region. Her menstrual history revealed the use of folded cloths instead of sanitary pads during her menstruation. Moreover, she washed those clothes with water and hanged them in the clothesline outside to let them dry before reuse. Examination of the external genitalia multiple ulcers measuring 1X1 cm on the inner surface of the labia minora, heavily infested with large number of maggots. The patient was admitted for 4 days during which she was given antibiotics, analgesics and anti-inflammatory medication. Daily local asepsis of the wound with antiseptic solution, betadine was done. We removed more than 30 larvae by the fourth day after which no more larvae were seen and she gradually recovered in the following days. It is our opinion that the cause of vulvar myiasis in our patient was her poor sanitary hygiene. Simple measures such as washing clothes thoroughly, drying and ironing of clothes are also necessary to reduce the risk of this human myiasis.

Unlabelled: Abdominal tuberculosis (TB) constitutes about 12% of the extrapulmonaryTB. Abdominal TB can present with varying signs and symptoms likevague abdominal pain, abdominal mass, ascites and intestinal obstruction. Intestinal perforation is a relatively uncommon but a serious complication of abdominal TB. Antitubercular drugs are considered extremely effective but their role in the presence of a stenotic lesion of the bowel is controversial. Once symptoms of bowel obstruction or peritonitis appear, antitubercular drugs are of little use and surgery is inevitable. We report a case of abdominal TB in a patient under antitubercular treatment who later developed multiple intestinal strictures and a perforation., Keywords: perforation; stricture; tuberculosis.

Tuberculosis (TB) is a major public health problem in developing countries including Nepal. One of the common presentations of TB is pleural effusion. The diagnosis of tubercular pleural effusion can be difficult because of the low rate of detecting tubercule bacilli by direct stain and culture of pleural fluid for acid-fast bacilli (AFB). Pleural biopsy can be useful but is invasive and requires experts. In this context, pleural fluid Adenosine Deaminase (ADA) level has been proposed as easy, cheap and highly sensitive test for diagnosis of TB pleural effusion. The present study was undertaken to define the role ofpleural fluid ADA value in accurate diagnosis of TB pleural effusion. A Prospective analysis of 100 patients admitted in Nepal Medical College and teaching Hospital with pleural effusion was done. Pleural fluid ADA level was evaluated in all patients, and significance of pleural fluid ADA level in TB pleural effusion was studied. It was found that mean ADA level in pleural fluid was 105.8 +/- 67.23 U/L in cases of TB, as compared to 16.83 +/- 8.91 U/L in malignancy, 44.53 +/- 32.84 U/L in parapneumonic effusion and 15.94 +/- 4.88 U/L in patients with miscellaneous diagnosis. For a cut-off value of 42.19 U/L for diagnosis of TB pleural effusion, sensitivity was found to be 90.8% and specificity 82.8%. Almost all patients diagnosed to have TB pleural effusion responded completely to anti-tubercular treatment. So, we concluded that pleural fluid ADA analysis could be easy, cheap and highly sensitive and specific test for diagnosis of TB pleural effusion.

The present study was undertaken to predict the persons prone to suffer from early onset of hypertension. Healthy sedentary volunteers (age 18-25 years) having normal blood pressure were asked about their history of familial hypertension, smoking-habit, alcohol consumption, existing worries/anxieties; these being the predisposing factors of hypertension. The blood pressure of them was recorded (casual baseline blood pressure). Maximum voluntary contraction (MVC) was noted as maximum pressure (in Kg) sustained during 3 sec of handgrip using a handgrip dynamometer. Thereafter, the participant was asked to sustain isometric handgrip at one third of MVC for one minute with the same instrument (isometric handgrip-test). Then, blood pressure was measured and the subject was allowed to rest. Three minutes after the handgrip test, the blood pressure was noted again (recovery blood pressure). Handgrip-test produced a rise in systolic blood pressure in all male volunteers. Amongst them, with predisposing factors of hypertension, diastolic blood pressure remained significantly higher than casual baseline diastolic blood pressure even after 3 minutes of withdrawal of stressor. Whereas, in males with no predisposing factors of hypertension, the diastolic blood pressure approached almost the baseline casual blood pressure. In all female participants, no significant difference was noted between the casual baseline blood pressure and blood pressure after recovery. Results indicated that the young men who presented prolonged elevated diastolic blood pressure, in response to handgrip test would be at high risk of early onset of hypertension, as sympathetic over-activity prevails in them for longer time.

The use of Internet for education, recreation and communication is increasing day by day. Nevertheless, the possibility of exploitation and addiction leading to impairment in academic performance and emotional balance cannot be denied, especially among young population. The study was aimed to measure the degree of Internet addiction among a group of medical students. Internet addiction test questionnaire developed by Young was used to assess mild, moderate and severe addiction. Amongst the study population (n=130, age 19-23 years), 40% had mild addiction. Moderate and severe addiction was found in 41.53% and 3.07% of the participants respectively. The study revealed that 24% often and 19.2% always found themselves using Internet longer than they had planned or thought. Late night Internet surfing leading to sleep deprivation was found in 31.53% of the participants. Almost one fourth of them (25.38%) occasionally tried to cut down the time they spent on the Internet but failed and 31.53% sometimes experienced restlessness when deprived of Internet access. Results reflected that a significant number of participants suffered from mild to moderate addiction. The role of counseling and education should be emphasized for prevention of Internet addiction.

Birth weight (BW) is an important determinant of infant's well being. Several factors such as mothers' genetic characteristics, socio-cultural, demographic, behavioral factors, prepregnancy body mass index (BMI), gestational weight gain (GWG) etc contribute to birth weight. This study assesses the anthropometric measurement of ethnic Nepalese women belonging to Sherpa/Tamang community and Brahmin/Chhetri community and the neonatal outcome in this population. A retrospective study was done in singleton pregnant women of Sherpa/Tamang and Brahmin/Chhetri community who delivered baby in Nepal Medical College and Teaching Hospital from April 2007 to March 2008 to examine the association between the maternal Body Mass Index (BMI) and the gestational weight gain among the two ethnic communities and the birth weight of newborns. Among 206 Sherpa women who met the eligibility criteria, the mean BMI of Sherpa/Tamang community was 23.53 +/- 2.28 which was statistically higher than the Brahmin/Chhetri community (21.6 +/- 2.32). Among Sherpa/Tamang community, the mean gestational weight gain was 12.8 +/- 3.4 kg and the mean birth weight was 3460 +/- 410 grams. Similarly among Brahmin/Chhetri community, mean gestation weight gain was 10.3 +/- 3.1 kg and the mean birth weight was 2960 +/- 340 gm. Maternal BMI, gestational weight gain and birth weight of the newborn was significantly higher in Sherpa/Tamang community and the Increasing BMI and the gestational weight gain was found to have strong association with the birth weight of the newborns among this ethnic community.

Color vision deficiency, most of the time remains an unnoticed problem; although it is not very rare. The faculty of appreciation of color is essential for our smooth daily activities. Unfortunately, even many doctors do not know the severity of their color vision deficiency and tend to assume it as slight, and a few, as in the general population, do not know about their disability. Some common difficulties reported by medical practitioners and medical students were in recognizing- widespread body color changes (pallor, cyanosis, jaundice, rashes, erythema of skin), colorful charts, slides, test-strips for blood and urine, body products: blood or bile in urine, faeces, sputum, vomit, microscopy, mouth and throat conditions, impressions presented in the Ishihara chart, titration end-points, tissue identification (surgery) etc. The present study was undertaken to evaluate the presence of congenital color vision deficiencies among the medical students. The study was carried out among the 1st and 2nd year medical students of Nepal Medical College and Teaching Hospital (n= 120) with the help of Ishihara chart, that was shown to all participants. They were asked to read the impressions in the color chart. The impression perceived by a person with normal color vision was different from the impression perceived by a person with color vision deficiency. It was noted that, among the study population (n=120) 5.83% of the volunteers were color weak. Amongst the color-deficient volunteers, 57.0% were protanopic while 43.0% were deuteranopic. Medical students must be made aware of their congenital color vision deficiency and its effects on their work. Screening will enable the student and later the doctor to become aware of limitations in their powers of observation and devise ways of overcoming them; the patient will be protected from harm and litigation may be avoided when doctors have adapted their practice to their deficiency. Medical students and physicians must be screened for color vision deficiency and advised about it so they can take special care in clinical practice.