Long-Range Surface Plasmon Resonance–Based Sensitivity Study on D-shaped Ag-MgF2-Coated Models with Analyte Variations

In this report, a novel D-shaped long-range surface plasmon resonance (LRSPR) fiber base sensor has been introduced. The demonstration of proposed sensor involves two D-shaped silver-coated models to study the sensitivity responses. The entire study with the constructed models is based on a single-mode fiber. The models are multilayered consisting of metal, dielectric, and analyte as separate layers. Silver (Ag) and magnesium fluoride (MgF2) strips are used as metal and dielectric layers respectively. The constituency of analyte as an interface excellently standardized the models for sensitivity detection. In this report, a large range of analyte refractive indices (RI) which varies from 1.33 to 1.38 is appraised for the proposed models to characterize the sensitivity. The entire context is encompassed by the wavelength region from 450 to 850 nm with an interval of 20 nm. Sensitivities in this report are measured based on the analyte position from the core and metal for both models. For each of the two models, the analyte is placed as the top layer. RIs of the applied metal (Ag) are measured using the Drude-Lorentz formula. The simulated sensitivities for model-1 and model-2 vary from 6.3?×?10³ nm/RIU to 8.7?×?10³ nm/RIU.

     

Effect of Spinal Cord Compression on Local Vascular Blood Flow and Perfusion Capacity

Spinal cord injury (SCI) can induce prolonged spinal cord compression that may result in a reduction of local tissue perfusion, progressive ischemia, and potentially irreversible tissue necrosis. Due to the combination of risk factors and the varied presentation of symptoms, the appropriate method and time course for clinical intervention following SCI are not always evident. In this study, a three-dimensional finite element fluid-structure interaction model of the cervical spinal cord was developed to examine how traditionally sub-clinical compressive mechanical loads impact spinal arterial blood flow. The spinal cord and surrounding dura mater were modeled as linear elastic, isotropic, and incompressible solids, while blood was modeled as a single-phased, incompressible Newtonian fluid. Simulation results indicate that anterior, posterior, and anteroposterior compressions of the cervical spinal cord have significantly different ischemic potentials, with prediction that the posterior component of loading elevates patient risk due to the concomitant reduction of blood flow in the arterial branches. Conversely, anterior loading compromises flow through the anterior spinal artery but minimally impacts branch flow rates. The findings of this study provide novel insight into how sub-clinical spinal cord compression could give rise to certain disease states, and suggest a need to monitor spinal artery perfusion following even mild compressive loading.     

Promotion of Growth in Mungbean (Phaseolus aureus Roxb.) by Selenium is Associated with Stimulation of Carbohydrate Metabolism

The mungbean plants were grown hydroponically in the absence (control) or presence of 0.1, 0.25, 0.50 and 0.75 ppm selenium (as sodium selenate) for 10 days. The growth of shoots and roots increased with application of selenium with greater extent in shoots. With 0.5 and 0.75 ppm Se levels, the shoot growth was stimulated by 24% to 27% over control, respectively, while the roots showed a corresponding increase of 18-19%, respectively. The shoot-to-root ratio was enhanced significantly with Se application and maximum effects occurred at 0.75 ppm Se. A significant increase was observed in chlorophyll and cellular respiration ability with 0.5 and 0.75 ppm selenium. The increase in growth by selenium was accompanied by elevation of starch, sucrose and reducing sugars. The activity of starch hydrolysing enzymes--amylases and sucrose hydrolysing enzyme--invertase was stimulated significantly with selenium. This was associated with elevation of activities of sucrose synthesising enzymes--sucrose synthase and sucrose phosphate synthase. It was concluded that increase in growth of shoots and roots by application of Se was possibly the result of up-regulation of enzymes of carbohydrate metabolism thus providing energy substrates for enhanced growth.     

Biofilm acts as a microenvironment for plankton-associated Vibrio cholerae in the aquatic environment of Bangladesh

The role of biofilm as a microenvironment of plankton-associated Vibrio cholerae was investigated using plexiglass as a bait. A total of 72 biofilm samples were tested using culture, direct fluorescent antibody (DFA) and molecular techniques following standard procedures. Culturable V. cholerae (smooth and rugose variants) were isolated from 33% of the samples. V. cholerae O1 were detected by FA technique throughout the year except April and June. All V. cholerae O1 isolates were positive for tcpA, ctxA and ace genes while V. cholerae non-O1, non-O139 isolates lacked these genes. V. cholerae O1 (both Inaba and Ogawa) strains had identical ribotype pattern (R1), but V. cholerae non-O1, non-O139 had different ribotype patterns. All V. cholerae O1 strains were resistant to vibrio-static compound (O/129). All V. cholerae O1 except one were resistant to trimethoprime-sulphamethoxazole, streptomycin, nalidixic acid and furazolidone but sensitive to ciprofloxacin, and tetracycline. This study indicates that plexiglass can act as a bait to form biofilm, a microenvironment that provides shelter for plankton containing V. cholerae in the aquatic environment of Bangladesh.     

A case with unilateral hypoglossal nerve injury in branchial cyst surgery

ABSTRACT: An 11 years old boy came, with complain of mild dysarthria. Examination revealed marked hemiatrophy of left side of the tongue. Five months back he underwent ipsilateral branchial cyst operation. To our knowledge, no case was reported. After branchial cyst operation if there is any residual remnant chance of recurrence is very high.     

Occurrence, seasonality and genetic diversity of Vibrio vulnificus in coastal seaweeds and water along the Kii Channel, Japan

Vibrio vulnificus is a ubiquitous toxigenic bacterium found in a coastal environment but little is known about its occurrence and seasonality among seaweeds, which are widely consumed as seafood in Japan. Therefore, we have observed the bacterium's abundance in seawater and seaweed samples from three areas of the Kii Channel, Japan, during June 2003 to May 2004. A total of 192 samples were collected: 24 from each source in summer, autumn, winter and spring. The samples were selectively cultivated following the most probable number (MPN) technique. Vibrio vulnificus population ranged from 0 to 10(3) MPN 100 mL(-1) seawater or 10 g seaweeds; higher counts were observed during summer. The optimum temperature, salinity and pH for the bacterium were 20-24 degrees C, 24-28 p.p.t. and 7.95-8.15, respectively. However, seaweeds always contained higher V. vulnificus than seawater. Among 280 V. vulnificus strains, detected by species-specific colony hybridization and PCR, 78, 74, 11 and 16 were from seaweeds and 46, 42, 2 and 11 were from seawater during summer, autumn, winter and spring, respectively. Ribotyping of 160 selected strains revealed a higher genotypic diversity (18 patterns) among strains from seaweeds than from seawater (10 patterns). Seaweeds can thus act as a potential habitat for V. vulnificus and are more unsafe for consumption during summer.     

Factors associated with in-hospital mortality of adult tetanus patients–a multicenter study from Bangladesh

BackgroundTetanus, a vaccine-preventable disease, is still occurring in the elderly population of low- and middle-income countries with a high case-fatality rate. The objective of the study was to elucidate the factors associated with in-hospital mortality of tetanus in Bangladesh.MethodsThis prospective observational study, conducted in two specialized infectious disease hospitals, conveniently selected adult tetanus patients (≥18 years) for inclusion. Data were collected through a preformed structured questionnaire. Kaplan Meier survival analysis and univariate and multivariable Cox regression analysis were carried out to assess factors associated with in-hospital mortality among patients. All analysis was done using Stata (version 16) and SPSS (version 26).ResultsA total of 61 tetanus cases were included, and the overall in-hospital mortality rate was 34.4% (n = 21). Patients had an average age of 46.49 ±15.65 years (SD), and the majority were male (96.7%), farmers (57.4%), and came from rural areas (93.4%). Survival analysis revealed that the probability of death was significantly higher among patients having an age of ≥ 40 years, incubation time of ≤12 days, onset time of ≤ 4 days, and having complication(s). However, on multivariable Cox regression analysis, age (adjusted hazard ratio [aHR] 4.03, 95% Confidence Interval [CI] 1.07–15.17, p = 0.039) and onset time (≤4 days) (aHR 3.33; 95% CI 1.05–10.57, p = 0.041) came as significant predictors of in-hospital mortality after adjusting for incubation period and complications.ConclusionOlder age and short onset time are the two most important determinants of in-hospital mortality of tetanus patients. Hence, these patients require enhanced emphasis and care.     

Polyphosphate stores enhance the ability of Vibrio cholerae to overcome environmental stresses in a low-phosphate environment

Vibrio cholerae, the causative agent of Asiatic cholera, has been reported to make large quantities of polyphosphate. Inorganic polyphosphate is a ubiquitous molecule with a variety of functions in prokaryotic and eukaryotic cells. We constructed a V. cholerae mutant with a deletion in the polyphosphate kinase (ppk) gene. The mutant was defective in polyphosphate biosynthesis. Deletion of ppk had no significant effect on production of cholera toxin, hemagglutinin/protease, motility, biofilm formation, and colonization of the suckling mouse intestine. The wild type and mutant had similar growth rates in rich and minimal medium and exhibited similar phosphate uptake and alkaline phosphatase induction. In contrast to ppk mutants from other gram-negative bacteria, the V. cholerae mutant survived prolonged starvation in LB medium and artificial seawater basal salts. The ppk mutant was significantly more sensitive to low pH, high salinity, and oxidative stress when it was cultured in low-phosphate minimal medium. The ppk mutant failed to induce catalase when it was downshifted to phosphorus-limiting conditions. Furthermore, the increased sensitivity of the ppk mutant to environmental stressors in phosphate-limited medium correlated with a diminished capacity to synthesize ATP from intracellular reservoirs. We concluded that polyphosphate protects V. cholerae from environmental stresses under phosphate limitation conditions. It has been proposed that toxigenic V. cholerae can survive in estuaries and brackish waters in which phosphorus and/or nitrogen can be a limiting nutrient. Thus, synthesis of large polyphosphate stores could enhance the ability of V. cholerae to survive in the aquatic environment.     

Intermittent nutritional stimulus by short-term treatment of high-energy diet promotes ovarian performance together with increases in blood levels of glucose and insulin in cycling goats

The aim of this study was to determine if short-term intermittent treatments of high-energy diet have any stimulatory effects on ovarian function and metabolic status in goat. Cycling Shiba goats were divided into treatment (TG; n=6) and control (CG; n=6) groups. After the detection of ovulation (1st ovulation, Day 0) by ultrasonography, a high-energy diet (250% of maintenance) was fed to the TG from Day 12 to Day 15 (4 days) and from Day 18 to Day 21 (4 days). The high-energy diet comprised 1000 g hay-cubes and 300 g of concentrated feed/head/day (approximately 15 MJ of digestible energy/day). The CG was offered maintenance diet throughout the experiment. Transrectal ultrasound examinations were conducted every other day during the luteal phase and were conducted daily during the follicular phase. Blood samples were collected daily from Day -2 to 7 days after ovulation (2nd ovulation) following the nutritional treatment for analysis of follicle stimulating hormone (FSH), progesterone, oestradiol, glucose and insulin in plasma. Two wave-like rises in the concentrations of glucose and insulin appeared in response to the intermittent nutritional stimulus. Mean plasma concentrations of glucose and insulin were significantly (P<0.05) higher in the TG than in the CG on almost all days during each treatment period. For ovarian performance, the total number of follicles that developed on the day prior to the 2nd ovulation in the TG (7.5 ± 2.7) was significantly higher than that of the CG (4.5 ± 2.6). Ovulation rate of the 2nd ovulation (4.5 ± 1.0) in the TG was significantly higher than that of the 1st ovulation (3.0 ± 0.6) of the TG and than both 1st (2.5 ± 0.5) and 2nd (2.7 ± 0.5) ovulations of the CG. No significant difference was detected in the concentrations of FSH, progesterone and oestradiol throughout the experiment between TG and CG. The present experiment demonstrated that short-term intermittent nutritional stimulus from the luteal phase increased the total number of ovulatory follicles and the ovulation rate in association with increasing plasma concentrations of glucose and insulin in goats.     

Mutation in the glycosylated gag protein of murine leukemia virus results in reduced in vivo infectivity and a novel defect in viral budding or release

All gammaretroviruses, including murine leukemia viruses (MuLVs), feline leukemia viruses, and gibbon-ape leukemia virus, encode an alternate, glycosylated form of Gag polyprotein (glyco-Gag or gPr80gag) in addition to the polyprotein precursor of the viral capsid proteins (Pr65gag). gPr80gag is translated from an upstream in-frame CUG initiation codon, in contrast to the AUG codon used for Pr65gag. The role of glyco-Gag in MuLV replication has been unclear, since gPr80gag-negative Moloney MuLV (M-MuLV) mutants are replication competent in vitro and pathogenic in vivo. However, reversion to the wild type is frequently observed in vivo. In these experiments, in vivo inoculation of a gPr80gag mutant, Ab-X-M-MuLV, showed substantially lower (2 log) initial infectivity in newborn NIH Swiss mice than that of wild-type virus, and revertants to the wild type could be detected by PCR cloning and DNA sequencing as early as 15 days postinfection. Atomic force microscopy of Ab-X-M-MuLV-infected producer cells or of the PA317 amphotropic MuLV-based vector packaging line (also gPr80gag negative) revealed the presence of tube-like viral structures on the cell surface. In contrast, wild-type virus-infected cells showed the typical spherical, 145-nm particles observed previously. Expression of gPr80gag in PA317 cells converted the tube-like structures to typical spherical particles. PA317 cells expressing gPr80gag produced 5- to 10-fold more infectious vector or viral particles as well. Metabolic labeling studies indicated that this reflected enhanced virus particle release rather than increased viral protein synthesis. These results indicate that gPr80gag is important for M-MuLV replication in vivo and in vitro and that the protein may be involved in a late step in viral budding or release.