Molecular architecture of the thylakoid membrane: lipid diffusion space for plastoquinone

We have determined the stoichiometric composition of membrane components (lipids and proteins) in spinach thylakoids and have derived the molecular area occupied by these components. From this analysis, the lipid phase diffusion space, the fraction of lipids located in the first protein solvation shell (boundary lipids), and the plastoquinone (PQ) concentration are derived. On the basis of these stoichiometric data, we have analyzed the motion of PQ between photosystem (PS) II and cytochrome (cyt.) bf complexes in this highly protein obstructed membrane (protein area about 70%) using percolation theory. This analysis reveals an inefficient diffusion process. We propose that distinct structural features of the thylakoid membrane (grana formation, microdomains) could help to minimize these inefficiencies and ensure a non-rate limiting PQ diffusion process. A large amount of published evidence supports the idea that higher protein associations exist, especially in grana thylakoids. From the quantification of the boundary lipid fraction (about 60%), we conclude that protein complexes involved in these associations should be spaced by lipids. Lipid-spaced protein aggregations in thylakoids are qualitatively different to previously characterized associations (multisubunit complexes, supercomplexes). We derive a hierarchy of protein and lipid interactions in the thylakoid membrane.

Effect of low-dose acute X-irradiation on the frequencies of chromosomal aberrations in human peripheral lymphocytes in vitro

In a coordinated research programme sponsored by the International Atomic Energy Agency, the frequencies of chromosomal aberrations induced in peripheral blood lymphocytes (in vitro) by 250 kV X-rays at low doses (0.4, 1, 2, 3, 5, 10 and 30 rad) were determined. Blood from 2 donors was used to conduct one master experiment at these dose levels. The culture time used was 48 h and all samples including the controls were processed according to a standard protocol. The coded slides were scored by investigators from 10 participating laboratories. The main results are the following: (1) the frequencies of all types of chromosome aberrations at 0.4 rad are significantly lower than the control values; (2) there is no increase in the frequencies of dicentrics up to 2 rad and in those of terminal deletions up to 5 rad; (3) the mean frequencies of all aberrations considered together are not significantly different from one another at 1, 2 and 3 rad (P = 0.05); and (4) over the entire dose range the dose-effect relationship is clearly non-linear. A fit of these data to a linear quadratic model (E(D) = c + alpha D + beta D2) showed that the observed total aberration frequencies at doses 1, 2, 3 and 5 rad are below the curve defined by the model. The deviations can be explained by an altered kinetics of aberration production at very low doses probably due to DNA repair mechanisms operating these cells.

Induction of sister-chromatid exchanges by restriction endonucleases

Restriction endonucleases Cfo 1, Pvu II, Sma I, Hpa II, Taq I and Hae III were tested for their ability to induce SCEs in CHO cells. The results indicate that the DNA double-strand breaks induced during S-phase by these enzymes lead to an increase in the frequencies of SCEs.

Elevated serum cancer antigen 125 levels in advanced abdominal tuberculosis

A 48-yr-old female presented with a 1-yr history of pain in the hypochondrium and epigastrium. All routine investigations and computed tomography (CT) of the abdomen were done. CT findings revealed a well-defined cystic mass in the right ovary, and ascitis with features suggestive of secondaries over the omentum and peritoneal surface. The serum CA125 was 1255 U/mL (normal range 0-35 U/mL), which was indicative of ovarian malignancy. An exploratory laparotomy was performed. Histopathological examination of organs revealed the presence of granuloma. The patient was advised to undergo antitubercular treatment (ATT) and follow-up every month. After 1 mo of ATT, the CA125 level came down to 42 U/mL, which was near normal. As tuberculosis requires only a conservative management, we suggest that in cases of abdominopelvic mass with or without ascitis, high serum CA125 should always raise a suspicion of tuberculosis and a laparoscopy combined with peritoneal biopsy should be performed to confirm the diagnosis. This will prevent unnecessary laparotomies. Moreover, serum CA125 can be used to monitor the response of disease to antitubercular treatment.

A gene expression signature distinguishes innate response and resistance to proteasome inhibitors in multiple myeloma

Extensive interindividual variation in response to chemotherapy is a major stumbling block in achieving desirable efficacy in the treatment of cancers, including multiple myeloma (MM). In this study, our goal was to develop a gene expression signature that predicts response specific to proteasome inhibitor (PI) treatment in MM. Using a well-characterized panel of human myeloma cell lines (HMCLs) representing the biological and genetic heterogeneity of MM, we created an in vitro chemosensitivity profile in response to treatment with the four PIs bortezomib, carfilzomib, ixazomib and oprozomib as single agents. Gene expression profiling was performed using next-generation high-throughput RNA-sequencing. Applying machine learning-based computational approaches including the supervised ensemble learning methods Random forest and Random survival forest, we identified a 42-gene expression signature that could not only distinguish good and poor PI response in the HMCL panel, but could also be successfully applied to four different clinical data sets on MM patients undergoing PI-based chemotherapy to distinguish between extraordinary (good and poor) outcomes. Our results demonstrate the use of in vitro modeling and machine learning-based approaches to establish predictive biomarkers of response and resistance to drugs that may serve to better direct myeloma patient treatment options.

Electroporation of salmon sperm for gene transfer: efficiency, reliability, and fate of transgene

Uptake of exogenous DNA by electroporated salmon sperm for gene transfer is being investigated. Our studies show that electroporated salmon sperm cells were more efficient and more reliable than untreated sperm in picking up exogenous DNA and subsequently transferring the DNA into salmon embryos. Indirect evidence suggest that some of the exogenous DNA was internalized in the sperm nuclei. The taken up DNA retained its integrity as demonstrated by PCR. The foreign DNA was detected in 15-month-old fish, and had a mosaic pattern of distribution. Integration of the foreign DNA occurred infrequently, and the expression of the foreign genes was poor. The potential of sperm-mediated gene transfer as a routine protocol for mass gene transfer in salmon will be dependent on the improvement of integration and expression of the foreign gene.

Pericardial synovial sarcoma

A 29-year-old young man presented with acute breathlessness. After investigative work-up he was found to have a massive pericardial tumour. Thoracotomy and near total surgical excision of the pericardial tumour was carried out. Histopathology and immunohistochemical markers study revealed it to be a synovial sarcoma arising from the left lateral pericardial surface. Postoperatively, he received external radiation and chemotherapy. Thirteen months after surgery he developed local recurrence which was unresectable.

Evaluation of reopening strategies for educational institutions during COVID-19 through agent based simulation

Many educational institutions have partially or fully closed all operations to cope with the challenges of the ongoing COVID-19 pandemic. In this paper, we explore strategies that such institutions can adopt to conduct safe reopening and resume operations during the pandemic. The research is motivated by the University of Illinois at Urbana-Champaign’s (UIUC’s) SHIELD program, which is a set of policies and strategies, including rapid saliva-based COVID-19 screening, for ensuring safety of students, faculty and staff to conduct in-person operations, at least partially. Specifically, we study how rapid bulk testing, contact tracing and preventative measures such as mask wearing, sanitization, and enforcement of social distancing can allow institutions to manage the epidemic spread. This work combines the power of analytical epidemic modeling, data analysis and agent-based simulations to derive policy insights. We develop an analytical model that takes into account the asymptomatic transmission of COVID-19, the effect of isolation via testing (both in bulk and through contact tracing) and the rate of contacts among people within and outside the institution. Next, we use data from the UIUC SHIELD program and 85 other universities to estimate parameters that describe the analytical model. Using the estimated parameters, we finally conduct agent-based simulations with various model parameters to evaluate testing and reopening strategies. The parameter estimates from UIUC and other universities show similar trends. For example, infection rates at various institutions grow rapidly in certain months and this growth correlates positively with infection rates in counties where the universities are located. Infection rates are also shown to be negatively correlated with testing rates at the institutions. Through agent-based simulations, we demonstrate that the key to designing an effective reopening strategy is a combination of rapid bulk testing and effective preventative measures such as mask wearing and social distancing. Multiple other factors help to reduce infection load, such as efficient contact tracing, reduced delay between testing and result revelation, tests with less false negatives and targeted testing of high-risk class among others. This paper contributes to the nascent literature on combating the COVID-19 pandemic and is especially relevant for educational institutions and similarly large organizations. We contribute by providing an analytical model that can be used to estimate key parameters from data, which in turn can be used to simulate the effect of different strategies for reopening. We quantify the relative effect of different strategies such as bulk testing, contact tracing, reduced infectivity and contact rates in the context of educational institutions. Specifically, we show that for the estimated average base infectivity of 0.025 (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$R_0 = 1.82$$\end{document}R0=1.82), a daily number of tests to population ratio T/N of 0.2, i.e., once a week testing for all individuals, is a good indicative threshold. However, this test to population ratio is sensitive to external infectivities, internal and external mobilities, delay in getting results after testing, and measures related to mask wearing and sanitization, which affect the base infection rate.

Evaluation of radiation-induced chromosomal aberrations in human peripheral blood lymphocytes in vitro: result of an IAEA-coordinated programme

The results of an IAEA coordinated programme on radiation induced chromosomal aberrations in human peripheral blood lymphocytes in vitro are presented. In a master experiment, a whole blood sample from one donor was irradiated with 200 R of X-rays. Different fixation times from 46 to 82 h were used. The progression of cells into mitosis was monitored by BrdUrd incorporation. 14 investigators took part in the scoring of chromosomal aberrations. The main conclusions of this study are: (1) The mean frequencies of aberrations changed with fixation time. (2) The number of cells scored as aberrant by different laboratories was very similar, but there was variability in the number of aberrations scored per aberrant cell. (3) The differences in the frequencies of aberrations between laboratories were minimal when the scoring was restricted to the first major peak of mitotic activity and sufficient cells were scored. It is concluded that using controlled experimentals conditions, human peripheral blood lymphocytes can effectively be used as a reliable biological dosimeter for absorbed radiation dose.

Uterine choriocarcinoma in a postmenopausal woman

Uterine choriocarcinoma developing in patients beyond reproductive age is a rare occurrence. We report a case of choriocarcinoma of uterine corpus in a 54-yr-old woman after 7 yr of menopause and 25 yr after last child birth. She presented with pain in the abdomen, and on radiological investigation a left uterine adnexal mass of 3.4 x 2.8 cm size was detected. Her serum CA125 level was 40 mIU/mL (normal up to 35 mIU/mL). Hysterectomy revealed an intramural growth in left uterine cornu measuring 3.5 x 3.0 x 2.5 cm. Histological features of the tumor were consistent with choriocarcinoma, and immunohistochemistry detected strong reactivity for beta-hCG in the tumor cells. Serum beta-hCG level 4 wk after surgery was 1345 mIU/mL. The patient was put on combination chemotherapy (EMACO). She achieved serological remission but showed a rise in serum beta-hCG level 4 wk after completion of chemotherapy. We conclude that a high level of suspicion may help in preoperative diagnosis of uterine choriocarcinoma in the postmenopausal age group. However, the response to chemotherapy in these cases may not be as encouraging as in choriocarcinoma of reproductive age.

DNA damage and prophage induction and toxicity of nitrofurantoin in Escherichia coli and Vibrio cholerae cells

Repair-deficient and repair-proficient strains of E. coli K12 were sensitive to nitrofurantoin treatment to varying degrees with the double mutant strain (uvrA 6, recA 13) being most sensitive. Ultraviolet absorption data and thermal chromatography through a hydroxyapatite column revealed that nitrofurantoin treatment of V. cholerae strain OGAWA 154 produced a maximal amount of 55% reversibly bihelical DNA at a nitrofurantoin dose of 120 micrograms/ml/h, which indicated the formation of inter-strand cross-links in DNA. Nitrofurantoin also produced prophage-lambda induction in E. coli K12 strain GY 5027: envA, uvrB, ampA 1, strA (lambda), in a dose-dependent manner, the maximum induction being highly significant (P less than 0.001). Previously published mutation data coupled with the prophage induction data presented here suggest that the genotoxic properties of nitrofurantoin are mediated through the SOS pathway.

Utility of free/total prostate specific antigen (f/t PSA) ratio in diagnosis of prostate carcinoma

The discovery that PSA exists in serum in both free and complexed forms led to development of immunoassays specific for different PSA forms. This helped in measuring free PSA in the presence of PSA-ACT (PSA-alpha antichymotrypsin), hence it was possible to calculate the percent free PSA or free to total PSA ratio, measurement of which was helpful in reducing the number of unnecessary biopsies significantly, while maintaining a high clinical sensitivity for detection of cancer. The study was performed on 103 consecutive male patients (mean age 68 +/- 10.8 years SD) comprising of 90 patients with benign disease (87%) and 13 prostate carcinoma patients (13%), who had histologically proven prostate cancer. Patients with total PSA between 2-25 ng/ml were included in the study. 30 normal healthy males with age 58 +/- 10 years, served as control. Serum total PSA and free PSA were analyzed using streptavidin biotin EIA method (M/s Roche Diagnostics, Germany). The mean total PSA in normal healthy control subjects was 1.86 +/- 1.07 ng/ml. It was increased significantly in diseased condition. Its mean concentration in carcinoma patients was 12.6 +/- 5.3 ng/ml and in benign patients it was 6.3 +/- 4.6 ng/ml. The free to total PSA ratio in all the three groups was significantly different (p < 0.004) from each other. In carcinoma patients, mean f/t PSA ratio was 0.12 +/- 0.06 as compared to 0.21 +/- 0.11 and 0.28 +/- 0.17 in benign patients and in control respectively. The sensitivity and specificity of the test was calculated at different f/t PSA ratio cutoff. At 0.1 cutoff value, sensitivity of the test was 54% and specificity was 83%. The positive predictive value (ppv) was 32% and negative predictive value (npv) was 92%. From cutoff value of 0.12 to 0.16, sensitivity was increased from 54% to 85% but specificity was reduced from 78% to 67%. The ppv did not show much change and npv was increased from 92% to 97%. Increasing the cut off value thereafter showed no change in sensitivity but specificity was further reduced to 40%, therefore in this patient series, f/t PSA ratio cutoff of 0.16 was found to be the appropriate cutoff value. Combination of this ratio cutoff with other parameters like serum total PSA, DRE and TRUS helped in increasing the sensitivity of the test and this also helped in reducing the number of unnecessary biopsies. In 103 men who were biopsied, 13 (12.6%) prostatic carcinoma were identified. Among these 13 cancer patients, 9 patients had abnormal findings in DRE.7 individuals out of these 9, also had free to total PSA ratio lower than 0.16 and would have been biopsied and diagnosed anyway. If we use only f/t PSA ratio less than 0.16, to decide whom to biopsy, we would have biopsied and diagnosed 11/13 cases i.e. sensitivity of 85% but If we decide to biopsy those patients who had abnormal DRE and those who had low f/t PSA ratio, we could identify 13/13 carcinoma i.e. 100% sensitivity. Combining the f/t PSA ratio with total PSA, DRE and TRUS findings could help in reducing the number of unnecessary biopsies. 37 patients who were negative for malignancy having total PSA in the range of 5-20 ng/ml, normal DRE and TRUS findings, have been biopsied but with combination of total PSA in the range of 5-20 ng/ml, normal findings in digital rectal examination and TRUS and f/t PSA ratio more than 0.16 (cutoff), we could have avoided 16 biopsies which were unnecessary that means there was 43% reduction in unnecessary biopsies.

Fructose 2,6-bisphosphate, carbohydrate partitioning, and crassulacean Acid metabolism

Fructose 2,6-bisphosphate (F 2,6-P(2)) was detected in the CAM species, Ananas comosus and Bryophyllum tubiflorum, and in C(3)- and CAM-Mesembryanthemum crystallinum. In both Mesembryanthemum tissues, F 2,6-P(2) was located outside the chloroplast. The levels of F 2,6-P(2), malate, starch, or soluble sugars were measured during various periods during the day-night cycle in the leaves of Ananas, a species which stores carbohydrate in an extrachloroplastic compartment, and in Bryophyllum, a species which stores carbon as starch in the chloroplast. In both species, the levels of F 2,6-P(2) were correlated with the stages of the day-night CAM cycle. Immediately following the dark-light transition the F 2,6-P(2) levels exhibited a rapid transient increase followed by a decrease. F 2,6-P(2) reached a daily minimum soon after the onset of deacidification and remained low until the malic acid pools approached their daily minima; the levels of F 2,6-P(2) then began a slow increase which accelerated during the period of afternoon CO(2) uptake. Immediately following the light-dark transition F 2,6-P(2) levels fluctuated. The levels were usually low after the fluctuations had ceased. The pools then increased as the rate of malate synthesis increased, remained at relatively constant high levels when the rates of malate synthesis were constant, and decreased as malate synthesis decreased towards the end of the dark period. The absolute levels of F 2,6-P(2) were always higher in Ananas than in Bryophyllum. The ratios of the activity of pyrophosphate fructose-6-phosphate l-phosphotransferase to cytoplasmic fructose 1,6-bisphosphatase and to phosphofructokinase were also far higher in Ananas than in Bryophyllum or in C(3)- or CAM-Mesembryanthemum.

In-vitro interaction between nitrofurantoin and Vibrio cholerae DNA

In-vitro interaction of nitrofurantoin with V. cholerae DNA resulted in a quenching and red spectral shift of the drug absorption pattern. Scatchard analysis revealed that the drug binding involved more than one processes and that the strongest mode of binding was characterised by an association constant (k) of 5.04 x 10(6) M-1 and the number of binding sites per nucleotide (n) of 0.015. Based on viscosity measurements, the mode of drug binding to DNA appeared to be through intercalation, the helix unwinding angle of supercoiled plasmid pBR322 DNA being 10 degrees. Nitrofurantoin binding to DNA resulted in an elevation of the thermal melting temperature (Tm) of DNA by 6 degrees C and inhibition of the action of DNase on DNA.

High-performance work system: a systematic review of literature

Purpose

This paper aims to review the existing body of knowledge on high-performance work systems (HPWS) with a special focus on the recent developments that strengthen its prevalence. Considering the current business ecosystem, the author proposes two more characteristics of HPWS which will add value to the literature. It also aims to propose several gaps in the literature considering the role of HPWS in the organization.

Design/methodology/approach

This paper uses a systematic literature review methodology to strengthen the concept, its connection with people and organization, theoretical underpinnings and intervening mechanisms that have not received much attention. The information collected from various studies was analyzed thematically and synthesized to assess the existing body of literature. For a better understanding of HPWS, the review is organized under the following subthemes: definition and meaning, conceptualization, technology infusion, relationship with people and organization, theories commonly used and positives and negative consequences of HPWS.

Findings

This study identifies and describes key characteristics of HPWS such as system, synergistic effect, performance and proposes two new characteristics – agility and adoption of technology. Further findings of this study indicate that HPWS has both positive and negative influences on employee outcomes. The positive outcome helps in the development of human capital that provides a competitive advantage to the organization. The study also underlines some negative influences of HPWS on employee behavior due to the misalignment of HR practices. Scope for further research is also provided for future researchers.

Originality/value

The paper adds the recent developments in the area of HPWS literature and proposes research directions for future researchers.

Integrating Pharmacogenomics Data-Driven Computational Drug Prediction with Single-Cell RNAseq to Demonstrate the Efficacy of a NAMPT Inhibitor against Aggressive, Taxane-Resistant, and Stem-like Cells in Lethal Prostate Cancer

Metastatic prostate cancer/PCa is the second leading cause of cancer deaths in US men. Most early-stage PCa are dependent on overexpression of the androgen receptor (AR) and, therefore, androgen deprivation therapies/ADT-sensitive. However, eventual resistance to standard medical castration (AR-inhibitors) and secondary chemotherapies (taxanes) is nearly universal. Further, the presence of cancer stem-like cells (EMT/epithelial-to-mesenchymal transdifferentiation) and neuroendocrine PCa (NEPC) subtypes significantly contribute to aggressive/lethal/advanced variants of PCa (AVPC). In this study, we introduced a pharmacogenomics data-driven optimization-regularization-based computational prediction algorithm ("secDrugs") to predict novel drugs against lethal PCa. Integrating secDrug with single-cell RNA-sequencing/scRNAseq as a 'Double-Hit' drug screening tool, we demonstrated that single-cells representing drug-resistant and stem-cell-like cells showed high expression of the NAMPT pathway genes, indicating potential efficacy of the secDrug FK866 which targets NAMPT. Next, using several cell-based assays, we showed substantial impact of FK866 on clinically advanced PCa as a single agent and in combination with taxanes or AR-inhibitors. Bulk-RNAseq and scRNAseq revealed that, in addition to NAMPT inhibition, FK866 regulates tumor metastasis, cell migration, invasion, DNA repair machinery, redox homeostasis, autophagy, as well as cancer stemness-related genes, HES1 and CD44. Further, we combined a microfluidic chip-based cell migration assay with a traditional cell migration/'scratch' assay and demonstrated that FK866 reduces cancer cell invasion and motility, indicating abrogation of metastasis. Finally, using PCa patient datasets, we showed that FK866 is potentially capable of reversing the expression of several genes associated with biochemical recurrence, including IFITM3 and LTB4R. Thus, using FK866 as a proof-of-concept candidate for drug repurposing, we introduced a novel, universally applicable preclinical drug development pipeline to circumvent subclonal aggressiveness, drug resistance, and stemness in lethal PCa.

Elevated serum cancer antigen 125 levels in advanced abdominal tuberculosis

A 48-yr-old female presented with a 1-yr history of pain in the hypochondrium and epigastrium. All routine investigations and computed tomography (CT) of the abdomen were done. CT findings revealed a well-defined cystic mass in the right ovary, and ascitis with features suggestive of secondaries over the omentum and peritoneal surface. The serum CA125 was 1255 U/mL (normal range 0-35 U/mL), which was indicative of ovarian malignancy. An exploratory laparotomy was performed. Histopathological examination of organs revealed the presence of granuloma. The patient was advised to undergo antitubercular treatment (ATT) and follow-up every month. After 1 mo of ATT, the CA125 level came down to 42 U/mL, which was near normal. As tuberculosis requires only a conservative management, we suggest that in cases of abdominopelvic mass with or without ascitis, high serum CA125 should always raise a suspicion of tuberculosis and a laparoscopy combined with peritoneal biopsy should be performed to confirm the diagnosis. This will prevent unnecessary laparotomies. Moreover, serum CA125 can be used to monitor the response of disease to antitubercular treatment.

Harnessing the power of native biocontrol agents against wilt disease of Pigeonpea incited by Fusarium udum

Fusarium wilt, caused by (Fusarium udum Butler), is a significant threat to pigeonpea crops worldwide, leading to substantial yield losses. Traditional approaches like fungicides and resistant cultivars are not practical due to the persistent and evolving nature of the pathogen. Therefore, native biocontrol agents are considered to be more sustainable solution, as they adapt well to local soil and climatic conditions. In this study, five isolates of F. udum infecting pigeonpea were isolated from various cultivars and characterized morphologically and molecularly. The isolate from the ICP 8858 cultivar displayed the highest virulence of 90%. Besides, 100 endophytic bacteria, 100 rhizosphere bacteria and three Trichoderma spp. were isolated and tested against F. udum isolated from ICP 8858 under in vitro conditions. Out of the 200 bacteria tested, nine showed highest inhibition, including Rb-4 (Bacillus sp.), Rb-11 (B. subtilis), Rb-14 (B. megaterium), Rb-18 (B. subtilis), Rb-19 (B. velezensis), Eb-8 (Bacillus sp.), Eb-11 (B. subtilis), Eb-13 (P. aeruginosa), and Eb-21 (P. aeruginosa). Similarly, Trichoderma spp. were identified as T. harzianum, T. asperellum and Trichoderma sp. Notably, Rb-18 (B. subtilis) and Eb-21 (P. aeruginosa) exhibited promising characteristics such as the production of hydrogen cyanide (HCN), cellulase, siderophores, ammonia and nutrient solubilization. Furthermore, treating pigeonpea seedlings with these beneficial microorganisms led to increased levels of key enzymes (POD, PPO, and PAL) associated with resistance to Fusarium wilt, compared to untreated controls. In field trials conducted for four seasons, the application of these potential biocontrol agents as seed treatments on the susceptible ICP2376 cultivar led to the lowest disease incidence. Specifically, treatments T2 (33.33) (P. aeruginosa) and T3 (35.41) (T. harzianium) exhibited the lowest disease incidence, followed by T6 (36.5) (Carbendizim), T1 (36.66) (B. subtilis), T4 (52.91) (T. asperellum) and T5 (53.33) (Trichoderma sp.). Results of this study revealed that, P. aeruginosa (Eb-21), B. subtilis (Rb-18) and T. harzianum can be used for plant growth promotion and management of Fusarium wilt of pigeonpea.

Effects of nitrofurantoin on viability, DNA synthesis and morphology of Vibrio cholerae cells

Nitrofurantoin caused a dose dependent inhibition of growth and decrease in viability of V. cholerae cells, the 10% (D10) and 37% (D37) survival doses being 50 and 19 micrograms/ml respectively. The drug at a concentration of 60 micrograms/ml caused 86% inhibition of DNA synthesis. Both light and electron microscopic observations revealed that treatment with nitrofurantoin (60 micrograms/ml for 1 hr at 37 degrees C) led to a significant filamentation of the V. cholerae cells, ultrastructure of the cell cytoplasm, plasma membrane and cell wall however remaining unaltered from those of untreated cells. The results are discussed in relation to DNA lesions produced by and the carcinogenic potential of the drug.

Major risk factors associated with severe COVID-19 outcomes in patients with multiple myeloma: Report from the National COVID-19 Cohort Collaborative (N3C)

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Background: Patients with multiple myeloma (MM), an age-dependent neoplasm of antibody-producing plasma cells, have compromised immune systems due to multiple factors that may increase the risk of severe COVID-19. The NCATS’ National COVID Cohort Collaborative (N3C) is a centralized data resource representing the largest multi-center cohort of ̃12M COVID-19 cases and controls nationwide. In this study, we aim to analyze risk factors associated with COVID-19 severity and death in MM patients using the N3C database. Methods: Our cohort included MM patients within the N3C registry diagnosed with COVID-19 based on positive PCR or antigen tests or ICD-10–CM. The outcomes of interest include all-cause mortality (including discharge to hospice) during the index encounter, and clinical indicators of severity (hospitalization/ED visit, use of mechanical ventilation, or extracorporeal membrane oxygenation/ECMO). Results: As of 09/10/2021, the N3C registry included 690371 cancer patients, out of which 17791 were MM patients (4707 were COVID-19+). The mean age at diagnosis was 65.9yrs, 57.6% were >65yo, 46.4% were females, and 21.8% were Blacks. 25.6% had a Charlson Comorbidity Index (CCI) score of ≥2. 55.6% required an inpatient or ED visit, and 3.65% required invasive ventilation. 11.4% developed acute kidney injury during hospitalization. Multivariate logistic regression analysis showed histories of pulmonary disease (OR 2.2; 95%CI: 1.7-2.8), renal disease (OR 1.8; 95%CI: 1.4-2.4), and black race (p<0.001) were associated with higher risk of severity. Interestingly, smoking status was significantly associated with a lower risk of severity (OR 0.7; 95%CI: 0.5-0.9). Further, protective association was also observed between COVID-19 severity and blood or marrow transplant (BMT) (OR 0.52; 95%CI: 0.4-0.7), daratumumab therapy (OR 0.64; 95%CI: 0.42-0.99) and COVID-19 vaccination (OR 0.28; 95%CI: 0.18-0.44). IMiDs were associated increase in the risk of COVID-19 severity (OR 2.1; 95%CI: 1.6-2.7). 2.3% of N3C-myeloma COVID-19+ patients died within the first 10 days, while 4.95% died within 30 days of COVID-19 hospitalization. Overall, the survival probability was 90.5% across the course of the study. Multivariate cox proportional hazard model showed that CCI score ≥2 (HR 4.4; 95%CI: 2.2-8.8), hypertension (HR 1.6; 95%CI: 1.02-2.4), IMiD (HR 2.6; 95%CI: 1.8-3.8) and proteasome inhibitor (HR 1.6; 95%CI: 1.1-2.5) therapy were associated with worse survival. COVID-19 vaccination (HR 0.195; 95%CI: 0.09-0.45) and BMT (HR 0.65; 95%CI: 0.4-0.995) were associated with lower risk of death. Conclusions: We have identified previously unpublished potential risk factors for COVID-19 severity and death in MM as well as validated some published ones. To the best of our knowledge, this is the largest nationwide study on multiple myeloma patients with COVID-19.

Liver transplant for viral hepatitis and fulminant hepatic failure

Since the introduction of hepatitis B immunoglobulin and nucleoside/nucleotide antivirals in the 1990's, outcomes of LT for hepatitis B virus (HBV)-related liver disease, regardless of whether for decompensated cirrhosis, hepatocellular carcinoma satisfying Milan criteria or fulminant hepatic failure (FHF), have been favorable with results comparable if not better to other liver transplant recipients. Unfortunately the same optimism does not hold true for hepatitis C which differs from post- transplant hepatitis B in many ways, most striking of which are the limited options for treatment of recurrent hepatitis C (HCV). As time has passed, the initial enthusiasm for liver transplantation for HCV has waned as the original excellent five year survival rates have now translated into disappointing medium- and long-term survival data. Cirrhosis can also develop in between 10-25% of patients by five years post-transplant which in turn has led to recurrent HCV-related cirrhosis emerging as an important yet controversial indication for retransplantation. A variety of diseases can cause FHF with drug-related hepatotoxicity, particularly from acetaminophen accounting for 50-60% of cases in United Kingdom and the United States while viral hepatitis appears to be declining as a cause. Although FHF is a relatively rare disease affecting approximately 2000 patients per year in the United States, it is associated with high morbidity and mortality without transplantation yet only 25% of patients in the United States undergo liver transplantation. This review article will discuss liver transplantation for HBV and HCV and will conclude with reviewing the etiology, epidemiology and management of FHF.

Oxidative damage of DNA and benzoate by chelated and non-chelated copper in presence of hydrogen peroxide

Benzoate hydroxylation test revealed that Cu(II) reacting with H2O2 produced OH degree radicals, which nicked or damaged DNA or hydroxylated benzoate, the extent of damage or hydroxylation depending on the period of incubation. The production of OH degree free radicals was also supported by the scavenger studies. Neither Cu(II) nor H2O2 alone could damage DNA or hydroxylate benzoate. EDTA-chelated Cu(II) plus H2O2 could damage DNA or hydroxylate benzoate only in presence of the biological reductant, L-cysteine, the damage increased with the increasing molar ratio of L-cysteine to Cu-EDTA. The biological relevance of the EDTA chelated Cu(II) and H2O2 system is discussed.

DNA damage and cell killing by nitrofurantoin in relation to its carcinogenic potential

Nitrofurantoin inhibited growth and produced loss of viability of Vibrio cholerae cells in a dose-dependent manner, the 10% (D10) and 37% (D37) survival doses being 18.0 and 5.5 micrograms/ml x hr. respectively. The drug also caused filamentation of the cells in a very significant manner. Ultraviolet absorption data and thermal chromatography through hydroxyapatite column revealed that nitrofurantoin treatment of Vibrio cholerae cells produced a maximum amount of 55% of DNA reversibly bihelical due to the formation of inter-strand cross-links. Helix-coil transition studies carried out by viscometric and also, spectrophotometric methods revealed that the nitrofurantoin-induced cross-links in Vibrio cholerae DNA, imparted to this DNA greater thermal stability than that of native DNA. The quantitative aspect and also the mode of nitrofurantoin action on DNA of Vibrio cholerae and Escherichia coli cells vis-à-vis the carcinogenic potential of the drug were discussed.