Survival of Extremotolerant Bacteria from the Mukundpura Meteorite Impact Crater.

Carbonaceous meteorites provide clues with regard to prebiotic chemistry and the origin of life. Geological Survey of India recorded a carbonaceous chondrite meteorite fall in Mukundpura, India, on June 6, 2017. We conducted a study to investigate the microbial community that survived the meteorite impact. 16S rRNA metagenomic sequencing indicates the presence of Actinobacteria, Proteobacteria, and Acidobacteria in meteorite impact soil. Comparative phylogenetic analysis revealed an intriguing abundance of class Bacilli in the impact soil. Bacillus thermocopriae IR-1, a moderately thermotolerant organism, was isolated from a rock, impacted by the Mukundpura meteorite. We investigated the resilience of B. thermocopriae IR-1 to environmental stresses and impact shock in a Reddy shock tube. Bacillus thermocopriae IR-1 survived (28.82% survival) the effect of shock waves at a peak shock pressure of 300 kPa, temperature 400 K, and Mach number of 1.47. This investigation presents the first report on the effect of impact shock on B. thermocopriae IR-1. The study is also the first report on studying the microbial diversity and isolation of bacteria from impact crater soil immediately after meteorite impact event.

Association of B12 deficiency and anemia synergistically increases the risk of high TNF-α levels among adolescent girls.

We investigated the association between iron status, B12, and inflammatory markers among 101 adolescent girls. We found that B12 showed significant negative association with tumor necrosis factor-alpha (TNF-α) (rs = -0.232, P = 0.020) and positive association with serum ferritin (SF) (rs = 0.209, P = 0.036) among girls. Our results showed that hepcidin discriminates anemic and non-anemic population under normal B12 conditions. The logistic regression analysis revealed that the risk of having higher TNF-α levels was 13.2 times higher in low B12 girls in the presence of anemia compared to the girls having normal hemoglobin and B12 levels.

Effects of oxidation on redox and cytotoxic properties of copper complex of Aß1-16 peptide.

The effect of oxidation on redox and cytotoxic properties of copper complex of amyloid beta (Aß) peptide was studied by gamma radiolysis. The oxidation of Aß1-16 and Aß1-16/Cu(II) complex was carried out using hydroxyl ((•)OH) radicals produced by gamma radiolysis and the products were analyzed using mass spectrometry. The presence of Cu(II) was found to enhance the oxidation of Aß1-16 peptide. The oxidation of residues Asp1, His6, and His13 was enhanced due to their involvement in copper binding. The oxidation of His residues of Aß1-16 peptide, which are chiefly responsible for copper binding, resulted in altered redox properties and subsequently in higher cytotoxicity of the Aß1-16 peptide in SH-SY5Y cells.

Effects of oxidation on copper-binding properties of Aß1-16 peptide: a pulse radiolysis study.

The reaction of hydroxyl radicals ((•)OH) with Aß1-16 peptide was carried out using pulse radiolysis to understand the effect of oxidation of peptide on its copper-binding properties. This reaction produced oxidized, dimeric and trimeric Aß1-16 peptide species. The formation of these products was established with the help of fluorescence spectroscopy and mass spectrometry. The mass spectral data indicate that the major site of oxidation is at His6, while the site for dimerization is at Tyr10. Diethyl pyrocarbonate-treated Aß1-16 peptide did not produce any trimeric species upon oxidation with (•)OH. The quantitative chemical modification studies indicated that one of the three histidine residues is covalently modified during pulse radiolysis. The copper-binding studies of the oxidized peptide revealed that it has similar copper-binding properties as the unoxidized peptide. Further, the cytotoxicity studies point out that both oxidized and unoxidized Aß1-16 peptide are equally efficient in producing free radicals in presence of copper and ascorbate that resulted in comparable cell death.

Antioxidant and Prooxidant Effects of Metal Dafonates on the NADPH-Dependent Lipid Peroxidation in the Murine Hepatic Microsomal System.

Dafone inhibits the lipid peroxidation significantly in a concentration dependent manner. The inhibition was found to be an uncompetitive type with the inhibition constant (Ki) of 62.5muM On the other hand complexation with metal ions results in a significant reversal from antioxidant to pro-oxidant properties for the resulting complexes which are cationic and with associated halometallate anions. The nature of the potentiation in case of the ferric compound was of competitive type with activation constant (Ka) having the value 32.5muM. The neutral copper-dafonate complex, however, inhibits lipid peroxidation with increase in concentration.

Contraceptive efficacy of norethindrone acetate (ENTA) implant: its release rate and fertility potential.

PIP: The contraceptive efficacy of norethindrone acetate (ENTA) implant was evaluated in a study of 79 healthy volunteers aged 19-30 years. The purpose of the study was to 1) relate the menstrual pattern to the average daily release rate of the hormone, 2) assess the concentration of NET in peripheral blood in cases of unintentional pregnancies and ascertain the risk to offspring in such cases, and 3) evaluate the fertility potential and menstrual pattern in the 1-year period after implant removal. In most subjects (59), the implant was removed between the 5th and 8th month. The average release rate was found to be 163.5 mcg/day in subjects with regular menstrual cycles (cycle interval of 25-32 days) compared with 190.9 mcg/day in those with an abnormal menstrual pattern (p0.05). The rate was 143.3 mcg/day in the 19 women who became pregnant during the trial, but this difference is not significant. 15 of the 19 pregnancies occurred between 4 and 8 months, suggesting that the contraceptive efficacy of this implant does not exceed 4-5 months. Mean NET concentration in the sera of the women who became pregnant was 122.5 pg/ml at the time of pregnancy diagnosis. Only 10 subjects complied with the recommendation that their pregnancy be terminated for medical indications. The remaining 9 subjects delivered 6 female and 3 male infants who appeared to clinically normal, despite the fact that 4 had been exposed to the steroid for over 6 weeks. 1 year follow-up was possible in 52 subjects. The menstrual pattern appeared to be regular during this period. 25 of the 44 women in this follow-up group who did not use contraceptive measures became pregnant during the 1st year after implant removal. Additionally, the 9 infants delivered to women during the study period were evaluated for 2-3 years. No adverse changes in growth and development have been observed. This finding suggests that reports associating teratogenicity and progestins in early pregnancy are exagerrated.^ieng

Clinical and immunological responses with Pr- beta-hCG-TT vaccine.

Six different batches of Pr-beta-hCG-TT vaccine have been evaluated in 23 women for the antibody response. The anti-sera formed against these conjugates were capable of reacting immunologically with the whole hCG in radioimmunoassays and also neutralized the biological activity of hCG in radioreceptor assays. The antibody titres attained peak levels 4-6 months after the first injection. The peak titres could not be sustained and most of the subjects showed a spiky pattern. One subject was considered as non-respective, two others had fairly low titres. Amongst the conjugates tested, batch 108 with SPLPS (sodium pthalate denatured with lipo-polysaccharides from S. entritides) seemed more promising, but the addition of the adjuvant was found to be pyrogenic and unlikely to be accepted clinically.

Use of plasma receptor test for HCG in fertility regulation.

PIP: A highly sensitive and specific pregnancy test, based on a radio-ligand assay system, is described; it was developed out of a need for more precision in pregnancy testing in a country which advocates menstrual regulation for pregnancy termination. The assay is based on identification of human chorionic gonadotropin by a plasma receptor and labeled antigen, and can be performed in about 60 minutes. Results of 428 serum samples collected from various clinical conditions were presented; these showed that the test had an accuracy of 99.7% in positive samples. Confirmation of these results was made by clinical follow-up, bioassays, histopathology, and radioimmunoassays. The only disadvantage to this test is the necessity for a radio-labeled isotope, and hence it can only be performed in areas and laboratories so equipped. The test's usefulness in cases of ectopic pregnancy, menstrual regulation, and threatened abortions is emphasized.^ieng

Metabolic and endocrine studies in women using norethindrone acetate implant.

Subcutaneously administered implant-D containing 40 mg of Norethindrone acetate in a single silastic implant was offered to 79 subjects who desired spacing of their family. The effect of constant release of steroid from this device on metabolic and endocrine functions was studied. Each subject in the pretreatment state served as her own control. The device was removed at 8 months initially and subsequently at 5-6 months. The clinical acceptability of this method was fairly high. The results reported in this study show that Norethindrone acetate administered in this way did not cause any adverse reactions on endocrine and metabolic functions as gauged by the parameters analysed.

Use of a radioreceptor test for HCG in women practicing contraception.

The importance of a simple, rapid and highly sensitive test for the diagnosis of early pregnancy cannot be overemphasized. In the present times when newer delivery systems of contraceptive agents and menstrual regulation procedures are increasingly used for fertility regulation, it is inevitable that confirmation of early pregnancy poses a severe problem. This radioreceptor test has been found to be very reliable even in early cases. A positive test was 100% accurate for pregnancy whereas the accuracy of a negative test was found to be 94.4%. Confirmation of these results was done by various other parameters like clinical, histological, radioimmunoassay for HCG and biological test for pregnancy.

PIP: An evaluation of a radioreceptor assay (RRA) for detection of early pregnancy is reported. Following delayed or irregular periods, 250 women were tested using the RRA. The test requires only .1 ml of plasma and the results are obtained within 2 hours. There were 179 positive tests, all of which were confirmed by other methods to be 100% accurate. The test was given to all but 7 of the patients within 2 weeks of the missed period. It is concluded that the RRA is more sensitive than most other immunological tests and less time-consuming than the radioimmunoassay.