Nanostructured material-based optical and electrochemical detection of amoxicillin antibiotic

The penicillin derivative amoxicillin (AMX) plays an important role in treating various types of infections caused by bacteria. However, excessive use of AMX may have negative health effects. Therefore, it is of utmost importance to detect and quantify the AMX in pharmaceutical drugs, biological fluids, and environmental samples with high sensitivity. Therefore, this review article provides valuable and up-to-date information on nanostructured material-based optical and electrochemical sensors to detect AMX in various biological and chemical samples. The role of using different nanostructured materials on the performance of important optical sensors such as colorimetric sensors, fluorescence sensors, surface-enhanced Raman scattering sensors, chemiluminescence/electroluminescence sensors, optical immunosensors, optical fibre-based sensors, and several important electrochemical sensors based on different electrode types have been discussed. Moreover, nanocomposites, polymer, and MXenes-based electrochemical sensors have also been discussed, in which such materials are being used to further enhance the sensitivity of these sensors. Furthermore, nanocomposite-based photo-electrochemical sensors and the market availability of biosensors including AMX have also been discussed briefly. Finally, the conclusion, challenges, and future perspectives of the above-mentioned sensing techniques for AMX detection are presented.     

Aluminum Toxicity: A Case Study on Tobacco (<i>Nicotiana tabacum</i> L.)

Aluminum is an abundant metal in the earth’s crust that turns out to be toxic in acidic environments. Many plants are affected by the presence of aluminum at the whole plant level, at the organ level, and at the cellular level. Tobacco as a cash crop (Nicotiana tabacum L.) is a widely cultivated plant worldwide and is also a good model organism for research. Although there are many articles on Al-phytotoxicity in the literature, reviews on a single species that are economically and scientifically important are limited. In this article, we not only provide the biology associated with tobacco Al-toxicity, but also some essential information regarding the effects of this metal on other plant species (even animals). This review provides information on aluminum localization and uptake process by different staining techniques, as well as the effects of its toxicity at different compartment levels and the physiological consequences derived from them. In addition, molecular studies in recent years have reported specific responses to Al toxicity, such as overexpression of various protective proteins. Besides, this review discusses data on various organelle-based responses, cell death, and other mechanisms, data on tobacco plants and other kingdoms relevant to these studies.     

Immunoaffinity chromatographic isolation of a high molecular weight seroreactive protein from Mycobacterium leprae cell sonicate

Abstract The purpose of this study was to isolate Mycobacterium leprae antigen(s) by immunoaffinity chromatography using immunoglobulins from leprosy patients and from rabbit anti- M. leprae hyperimmune serum coupled to CNBr-Sepharose 4B. A high molecular weigh ( M _r) M. leprae protein (MLP) with a subunit M _r of 22000 was isolated. MLP was recognized by monoclonal antibody MMPII1G4 which is known to react with MMPII, a 22 kDa protein of M. leprae . The N-terminal sequence of the 22 kDa subunit (Met-gln-gly-asp-pro-asp-val-leu-arg-leu-leu-asn-glu-gln-leu-thr) was identical to MMPII and to antigen D (bacterioferritin) of M. paratuberculosis . It showed 44% homology with N-terminal end of E. coli bacterioferritin. In ELISA, MLP showed 100% and 60% positivity with leprosy and TB sera respectively as compared to normal healthy sera. The role of bacterioferritin in M. leprae and the importance of MLP as an immunogen has been discussed.     

Altered flower/fruit clusters of the kitul palm used as roosts by the short-nosed fruit bat, Cynopterus sphinx (Chiroptera: Pteropodidae)

The short-nosed fruit bat (Cynopterus sphinx) creates bell-shaped cavities in flower/fruit clusters of the kitul palm (Caryota urens) by chewing and severing flower and fruit strings. These cavities (stem tents) in which the bats roost are usually about one metre deep and 30 cm in diameter. We observed groups of bats roosting in fully-formed stem tents during the daytime, and the construction and subsequent occupancy of newly formed tent cavities. Stem tents are similar in principle to leaf tents except, instead of being formed when bats chew veins and the surrounding tissues of leaves, stem tents are formed in C. urens when bats completely cut several of the central flower/fruit strings. Flower/fruit strings are mostly severed when they are in an immature stage, at times when they are thin and widely spaced. Once these strings thicken and become heavily-laden with mature fruits, bats cannot penetrate the cluster to sever them. Our observations suggest that a single male enters an immature flower or fruit cluster either from below or the sides and severs the central strings along the peduncle. In early phases of stem-tent construction, C. sphinx severs flower/fruit strings at a rate of about one or two per day, and cluster alteration may continue upwards to two months. Only one immature flower/fruit cluster on a C. urens tree is available for alteration by bats at any given time. That this bat does not roost in the fruit/flower cluster during the day, when a tent is under construction, and the accumulation of chewed flower and fruit strings beneath such a cluster in the morning, suggests that tent construction by C. sphinx is a night-time activity.     

Inhibition of aggregation of human platelets by 8,15-dihydroperoxides of 5,9,11,13-eicosatetraenoic and 9,11,13-eicosatrienoic acids

The dihydroperoxy derivative of arachidonic acid, 8,15-dihydroperoxy-5,9,11,13-eicosatetraenoic acid, at , is an effective inhibitor of the aggregation of human blood platelets, induced by ADP, epinephrine and collagen. The nature of the effect is time dependent. If ADP is added 60 sec after the inhibitor, the first phase of aggregation occurs but the second phase is suppressed. When the time is prolonged to 240 sec, the first phase of aggregation is almost completely eliminated. The corresponding dihydroxy derivative is without effect on aggregation. The corresponding dihydroperoxy derivative obtained from 8,11,14-eicosatrienoic acid is also an effective inhibitor.     

Physiological responses of mules on prolonged exposure to high altitude (3 650 m)

Eight healthy male animals were inducted and kept for 2 1/2 years at 3 650 m altitude and subjected to normal work schedules. Physiological measurements viz. heart rate, blood pressure, minute ventilation, oxygen consumption, respiration rate, hemoglobin, packed cell haematocrit volume and eosinophil count were made on these animals at periodic intervals. On acute induction to an altitude of 3 650 m these animals demonstrated a sudden increase in tidal volume, a decrease in Rf and no change in V_E, suggesting a decreased dead space/tidal volume ratio at altitude.However, all these changes stabilised within 3 weeks but on prolongation of stay, the physical state of these animals was adversely affected. The respiratory adjustments occurring on return to sea level appear to be a response to thermal stress. The initial increase in heart rate and blood pressure stabilised by the 2nd week.     

Retinoid metabolism in spontaneously transformed mouse fibroblasts (Balb/c 3T12-3 cells): enzymatic conversion of retinol to anhydroretinol.

Spontaneously transformed mouse fibroblasts (Balb/c 3T12-3 cells) displayed an increased adhesion when cultured in the presence of 10(-6) M all-trans retinol and acquired morphological characteristics of the normal phenotype. Thus it was of interest to investigate the metabolism of [15-(14)C]retinol in this system. Within 24 hours of culture, approximately 4.25% of the [(14)C]retinol was taken up by the cells. The hydrocarbon [(14)C]anhydroretinol was a major metabolic product and was identified by gas-liquid chromatography and by its typical ultraviolet absorption spectrum with maxima at 386, 364, and 346 nm. At 24 and 40 hours anhydroretinol represented 27% and 55%, respectively, of the total nonpolar metabolites or approximately 16% and 30% of the total radioactive products. Formalin-fixed fibroblasts or cultured intestinal mucosal cells did not convert retinol into anhydroretinol. A more polar product with a UV absorption maximum at 310 nm was also found. The time course of the synthesis of this product by 3T12 cells suggested a precursor-product relationship with anhydroretinol. A microsomal preparation from 3T12 cells was also active in synthesizing [(14)C]anhydroretinol and [(14)C]metabolite-310 from [(14)C]retinol. Moreover incubation of metabolite-310 with the 3T12 microsomes yielded anhydroretinol (40% conversion in 30 minutes), suggesting that metabolite-310 is an intermediate in the synthesis of anhydroretinol by these cells. Anhydroretinol appears to be an end product of the metabolism of retinol in 3T12-3 cells, as suggested by the finding that over 90% of [(14)C]anhydroretinol incubated for 30 hours with 3T12-3 cells was recovered unaltered, without the formation of detectable retroretinol, retinol, or retinoic acid.-Bhat, P. V., L. M. De Luca, S. Adamo, I. Akalovsky, C. S. Silverman-Jones, and G. L. Peck. Retinoid metabolism in spontaneously transformed mouse fibroblasts (Balb/c 3T12-3 cells): enzymatic conversion of retinol to anhydroretinol.     

Identification and size variation of terminal fragments of sheep pox virus genome

Terminal fragments of sheep pox virus DNA identified by snap-back analysis showed terminal covalent cross-links. Southern blot hybridization using a terminal fragment probe confirmed the termini and terminal repeats (common sequences) of the sheep pox virus genome. Terminal fragment length variability was observed between virus isolates.