Patients' acceptability of self-selected digital health services to support diet and exercise among people with complex chronic conditions: Mixed methods study.

Objective: The acceptability of being offered a choice from a suite of digital health service options to support optimal diet and exercise behaviors in adults with complex chronic conditions was evaluated. This study sought to understand many areas of acceptability including satisfaction, ease of use, usefulness and user appropriateness and perceived effectiveness. Methods: This mixed-methods study was embedded within a randomized-controlled feasibility trial providing digital health services managing diet and exercise for adults from specialist kidney and liver disease clinics. Post study surveys and semistructured interviews were used to determine patients' acceptability of the trial interventions. Quantitative (surveys) and qualitative (surveys and interviews) results were merged using integrative analysis and mapped to each construct of the modified version of the Theoretical Framework of Acceptability. Results: Seventeen interviews (intervention group) and 50 surveys (n = 24 intervention, n = 26 comparator) completed from a possible 67 participants were analyzed. In the intervention group, the survey results revealed high areas of acceptability for the digital health services including overall support received, ease of use, timely advice and feeling safe. The interviews also revealed high areas of acceptability including convenience, ability to adopt healthier behaviors and having regular interactions with health professionals. However, the interviews also revealed lower areas of acceptability as a result of absence of individualization, low digital literacy, and limitations from life circumstances. Conclusions: Recipients of digital health services that supported diet and exercise interventions found these useful, effective, and safe. Individualized care, technical support and patient confidence remain important to improve the acceptability of digital health service interventions.

Evaluating the Potential of a Novel Metabolic Syndrome Severity Score to Inform Exercise Interventions for People with Complex Chronic Conditions.

Aims: Exercise interventions positively affect numerous cardiometabolic risk factors. To better evaluate the health effects of exercise training, it may be more appropriate to evaluate risk factors together. The Metabolic Syndrome Severity Score (MetSSS) is a composite score representing cardiometabolic risk. Purpose: To evaluate the relationships between physical activity, neuromuscular fitness, exercise capacity, and the MetSSS in a heterogenous sample of people with complex chronic disease. Material and Methods: Fifty-three people with kidney or liver disease and at least one feature of the metabolic syndrome (MetS) were included. Pearson correlations were conducted between physical activity, neuromuscular fitness, exercise capacity, and the MetSSS. Linear regressions were performed for multi-level categorical variables. Independent variables with an association with MetSSS (P ≤ 0.2) were included in a multiple regression analysis. Results: The 6-minute walk test (6MWT) distance was inversely and independently associated with MetSSS [standardized beta coefficient (ß) = -0.31, P = 0.04]. No relationship was found between MetSSS and physical activity or neuromuscular fitness. Mean 6MWT in the highest tertile was 550 m (range: 505-620 m) and 346 m (range: 233-408 m) in the lowest. The analysis showed a medium-large between-group effect for the difference in MetSSS for the lowest and highest tertile of 6MWT [Eta squared (η2) = 0.16, P = 0.01]. Conclusions: Exercise capacity was inversely and independently associated with MetSSS in people with complex chronic disease. Clinical trials with exercise interventions are needed to further investigate if improvements in exercise capacity result in clinically significant changes in the MetSSS.

Bednar's tumor at right shoulder in an adult male: a case report of a rare entity.

Introduction and importance: Bednar tumor, a rare variant of dermatofibrosarcoma protuberans is a tumor with low malignant potential. Owing to limited studies, the pathogenesis and risk factor of this tumor are not clearly understood. The tumor extends from the epidermis to the dermal layers and even affects the surrounding bone. Here, the authors present a case of a 48-year-old male with a Bednar tumor, which was successfully managed by wide local excision and flap repair. Case presentation: Our patient presented to the hospital after the reappearance of mass, 6 years after the excision of the previously misdiagnosed lipoma. Vitals and systematic examination were normal. Local examination revealed an oval-shaped mass with a glistening surface on the right shoulder. The patient underwent wide excision and skin flap surgery for the treatment, and the diagnosis was confirmed through histopathological examination and immunohistochemistry for the CD34 marker. Clinical discussion: Bednar tumor is an infrequent skin tumor linked to genetic anomalies and is one of the rare variants [(<0.1%) of skin tumors]. Diagnosis can be done by histopathological examination and CD34 marker positivity via immunohistochemistry. This tumor is mistaken for lipoma, leading to recurrent growth postexcision. The tumor demands a broader resection due to the high chances of reoccurrence. Although Mohs micrographic surgery is the ideal approach, its limited availability in resource-constrained settings prompts alternative strategies. Conclusion: This case highlights the challenges of diagnosis, the rarity of the condition, and the need for vigilant follow-up due to the tumor's propensity for recurrence.

Incidence of Thromboembolic Complications Following Kidney Transplantation with Short and Extended Aspirin Prophylaxis: A Retrospective Single-Center Study.

BACKGROUND Aspirin prophylaxis has been associated with reduced graft-related thrombosis following kidney transplantation. Aspirin cessation, however, can increase risk of venous thromboembolic complications, including pulmonary thromboembolism and deep venous thrombosis. This single-center, retrospective, pre-post interventional study from Brisbane, Australia, aimed to compare the rate of thrombotic complications in 1208 adult kidney transplant recipients receiving postoperative aspirin for 5 days or >6 weeks. MATERIAL AND METHODS We enrolled1208 kidney transplant recipients who received 100 mg aspirin for 5 days (n=571) or >6 weeks (n=637) postoperatively. The primary outcome was venous thromboembolism (VTE) in the first 6 weeks after transplant, examined by multivariable logistic regression analysis. Secondary outcomes were renal vein/artery thrombosis, 1-month serum creatinine, rejection, myocardial infarction, stroke, blood transfusion, dialysis at day 5 and day 28, and mortality. RESULTS Sixteen (1.3%) patients experienced VTE (5-day n=8, 1.4%; >6-week n=8, 1.3%; P=0.8). Extended aspirin duration was not independently associated with a reduction in VTE (OR 0.91, 95% CI 0.32-2.57; P=0.9). Graft thrombosis was rare (n=3, 0.25%). Aspirin duration was not associated with cardiovascular events, blood transfusion, graft thrombosis, graft dysfunction, rejection, or mortality. VTE was independently associated with older age (OR 1.09, 95% CI 1.04-1.16; P=0.002), smoking (OR 3.59, 95% CI 1.20-13.2; P=0.032), younger donor age (OR 0.96, 95% CI 0.93-1.00; P=0.036), and thymoglobulin use (OR 10.5, 95% CI 3.09-32.1; P≥0.001). CONCLUSIONS Extended-duration aspirin use did not significantly reduce the incidence of VTE in the first 6 weeks following kidney transplantation. An association was identified between anti-human thymocyte immunoglobulin and VTE, which requires further assessment.

Pulmonary Tumor Embolism Complicated by Metastatic Liver Carcinoma in Female With Primary Breast Carcinoma.

Pulmonary tumor embolism (PTE) is a rare phenomenon typically presenting as dyspnea in cancer patients. Primary pathophysiology is similar to the thromboembolic disease of the pulmonary vasculature, which involves large vessels to small arterioles. This phenomenon occurs mostly in lung, stomach, liver, and breast adenocarcinoma. The symptoms of hypoxemia and the signs of hemodynamic instability and high-resolution computed tomography (CT) scans, along with a histopathological examination, are essential to make a confirmatory diagnosis of pulmonary tumor embolism. However, treatment options to effectively treat pulmonary tumor embolus are limited and still under investigation. We present a rare case of pulmonary tumor embolism in a patient with metastatic liver carcinoma and its management in a female with primary breast carcinoma.

Central Pontine Myelinolysis With Carbamazepine-Induced Syndrome of Inappropriate Antidiuretic Hormone and Its Management: A Case Report and Literature Review.

Aggressive treatment of hyper or hypoosmolar conditions can trigger osmotic demyelination syndrome. We describe the case of a 53-year-old male who began using carbamazepine to treat bipolar affective disorder and was later diagnosed with carbamazepine-induced syndrome of inappropriate antidiuretic hormone secretion. The patient's mental state gradually improved once the hyponatremia was corrected using 3% normal saline and supportive therapy. The patient presented to the outpatient clinic with confusion and altered sensorium. Brain computed tomography showed diffuse cerebral atrophy and periventricular ischemia demyelination alterations, and magnetic resonance imaging showed an enhanced section in the brainstem that included the pons, suggesting osmotic demyelination alterations. Ventilatory support and supportive therapy were initiated, and hyponatremia was rectified. Although the patient did well with the treatment, his prognosis was still dismal, so he was sent home with instructions to follow up.

Are Digital Health Technologies and Models of Nutrition Care the Future of Chronic Kidney Disease Management?

People living with chronic kidney disease (CKD) require long-term support at varying levels of individualization, intensity, and frequency. Mobile and digital models of nutrition care can facilitate long-term behavior change, address nutrition issues proactively, reduce travel burden, and reach people without access to health care more easily. However, while traditional health delivery continues to be digitally disrupted, there are many barriers to address before mobile and digitally supported models of nutrition care can become business as usual in nephrology and nutrition care practice. This paper overviews the current evidence base concerning the past and present mobile and digital health programs to improve nutrition in CKD and highlights the novel future trends in this field. The way nutrition and dietetic care can be feasible, safe, and potentially effective when delivered using various digital and virtual technologies, including consultations, assessments, establishment of diagnoses, formulation of plans, and monitoring/reviewing clinical progress is discussed. Of the available evidence to date, these modalities appear to improve dietary sodium intake and diet quality, self-efficacy, interdialytic weight gain, and body weight. Many barriers exist to sustaining the continued and widespread adoption of digital and mobile health-supported nutrition care in CKD. These include patient-, clinician-, and health system-specific and are discussed in detail. Mobile and digital-supported models of nutrition care present an exciting opportunity to assist kidney dietitians deliver patient-centred nutrition care in CKD.

Factors associated with contact tracing compliance among communities of color in the first year of the COVID-19 pandemic.

RATIONALE: The disproportionate impact of COVID-19 on communities of color has raised questions about the unique experiences within these communities not only in terms of becoming infected with COVID-19 but also mitigating its spread. The utility of contact tracing for managing community spread and supporting economic reopening is contingent upon, in part, compliance with contact tracer requests. OBJECTIVE: We investigated how trust in and knowledge of contact tracers influence intentions to comply with tracing requests and whether or not these relationships and associated antecedent factors differ between communities of color. METHOD: Data were collected from a U.S. sample of 533 survey respondents from Fall (2020) to Spring 2021. Multi-group SEM tested quantitative study hypotheses separately for Black, AAPI, Latinx, and White sub-samples. Qualitative data were collected via open-ended questions to inform the roles of trust and knowledge in contact tracing compliance. RESULTS: Trust in contact tracers was associated with increased intentions to comply with tracing requests and significantly mediated the positive relationship between trust in healthcare professionals and government health officials with compliance intentions. Yet, the indirect effects of trust in government health officials on compliance intentions were significantly weaker for the Black, Latinx, and AAPI samples compared to Whites, suggesting this strategy for increasing compliance may not be as effective among communities of color. Health literacy and contact tracing knowledge played a more limited role in predicting compliance intentions directly or indirectly, and one that was inconsistent across racial groups. Qualitative results reinforce the importance of trust relative to knowledge for increasing tracing compliance intentions. CONCLUSIONS: Building trust in contact tracers, more so than increasing knowledge, may be key to encouraging contact tracing compliance. Differences among communities of color and between these communities and Whites inform the policy recommendations provided for improving contact tracing success.

Temporal dysregulation of genes in lamb testis cell during sheeppox virus infection.

The present study was aimed to elucidate the host-virus interactions using RNA-Seq analysis at 1 h and 8 h of post-infection of sheeppox virus (SPPV) in lamb testis cell. The differentially expressed genes (DEGs) and the underlying mechanisms linked to the host immune responses were obtained. The protein-protein interaction (PPI) network analysis and ingenuity pathway analysis (IPA) illustrated the interaction between the DEGs and their involvement in cell signalling responses. Highly connected hubs viz. AURKA, CHEK1, CCNB2, CDC6 and MAPK14 were identified through PPI network analysis. IPA analysis showed that IL-6- and ERK5-mediated signalling pathways were highly enriched at both time points. The TP53 gene was identified to be the leading upstream regulator that directly responded to SPPV infection, resulting in downregulation at both time points. The study provides an overview of how the lamb testis genes and their underlying mechanisms link to growth and immune response during SPPV infection.

Utilizing Technology for Diet and Exercise Change in Complex Chronic Conditions Across Diverse Environments (U-DECIDE): Protocol for a Randomized Controlled Trial.

BACKGROUND: The metabolic syndrome is common across many complex chronic disease groups. Advances in health technology have provided opportunities to support lifestyle interventions. OBJECTIVE: The purpose of this study is to test the feasibility of a health technology-assisted lifestyle intervention in a patient-led model of care. METHODS: The study is a single-center, 26-week, randomized controlled trial. The setting is specialist kidney and liver disease clinics at a large Australian tertiary hospital. The participants will be adults with a complex chronic condition who are referred for dietetic assessment and display at least one feature of the metabolic syndrome. All participants will receive an individualized assessment and advice on diet quality from a dietitian, a wearable activity monitor, and standard care. Participants randomized to the intervention group will receive access to a suite of health technologies from which to choose, including common base components (text messages) and optional components (online and mobile app-based nutrition information, an online home exercise program, and group-based videoconferencing). Exposure to the optional aspects of the intervention will be patient-led, with participants choosing their preferred level of engagement. The primary outcome will be the feasibility of delivering the program, determined by safety, recruitment rate, retention, exposure uptake, and telehealth adherence. Secondary outcomes will be clinical effectiveness, patient-led goal attainment, treatment fidelity, exposure demand, and participant perceptions. Primary outcome data will be assessed descriptively and secondary outcomes will be assessed using an analysis of covariance. This study will provide evidence on the feasibility of the intervention in a tertiary setting for patients with complex chronic disease exhibiting features of the metabolic syndrome. RESULTS: The study was funded in 2019. Enrollment has commenced and is expected to be completed by June 2022. Data collection and follow up are expected to be completed by December 2022. Results from the analyses based on primary outcomes are expected to be submitted for publication by June 2023. CONCLUSIONS: The study will test the implementation of a health technology-assisted lifestyle intervention in a tertiary outpatient setting for a diverse group of patients with complex chronic conditions. It is novel in that it embeds patient choice into intervention exposure and will inform health service decision-makers in regards to the feasibility of scale and spread of technology-assisted access to care for a broader reach of specialist services. TRIAL REGISTRATION: Australian New Zealand Clinical Trial Registry ACTRN12620001282976; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=378337. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/37556.

Establishment and characterization of a continuous cell line from caudal fin of Labeo calbasu (Hamilton, 1822).

Labeo calbasu is an important food fish and candidate species for diversification of carp aquaculture. In the present study, we have established a continuous cell line, designated as L. calbasu fin (LCF), from caudal fin of L. calbasu using explant method. The cell line has been subcultured for over 73 passages and the LCF cells show optimal growth in Leibovitz's L-15 medium supplemented with 20% fetal bovine serum at a temperature of 28°C. In karyotype analysis, the modal chromosome number of LCF cells at 35th passage was found to be 50. The amplification and sequencing of partial fragments of mitochondrial genes, namely 16S rRNA and COI from LCF cells confirmed the origin of cell line from L. calbasu. The LCF cells could be successfully transfected with GFP reporter gene, indicating suitability of these cells for expression of foreign genes. Further, following inoculation with supernatant from Tilapia lake virus (TiLV) infected cell line, no cytopathic effects were observed in the LCF cells and cell pellet was negative for TiLV in RT-PCR, indicating that LCF cells were not susceptible to TiLV. The developed cell line has been submitted to National Repository of Fish Cell Lines being maintained at ICAR-National Bureau of Fish Genetic Resources, Lucknow (accession no. NRFC063). The newly developed LCF cell line would be helpful in investigating diseases affecting this candidate species particularly the ones suspected to be of viral etiology, and for cytotoxicity and transgenic studies.

Physical activity and exercise recommendations for people receiving dialysis: A scoping review.

INTRODUCTION: Remaining physically active is important to patients undertaking dialysis, however, clinical recommendations regarding exercise type, timing, intensity, and safety precautions vary. The purpose of this scoping review was to analyse and summarise recommendations for physical activity and exercise for people undertaking dialysis and identify areas that require further research or clarification. MATERIALS AND METHODS: A scoping review of literature from five bibliographic databases (Medline, Scopus, Web of Science, CINAHL, and SPORTDiscus) was conducted. Eligible articles included consensus guidelines, position statements, reviews, or clinical practice guidelines that included specific physical activity and exercise recommendations for people undertaking dialysis. Key search terms included "kidney disease" OR "kidney failure" OR "chronic kidney disease" OR "end stage kidney disease" AND guideline* OR consensus OR "position statement" OR prescription OR statement AND exercise OR "physical activity". Hand searching for relevant articles in all first twenty quartile 1 journals listed on SCImago under 'medicine-nephrology' and 'physical therapy, sports therapy and rehabilitation' using the terms 'exercise and dialysis' was undertaken. Finally, home pages of key societies and professional organisations in the field of sports medicine and nephrology were searched. RESULTS: The systematic search strategy identified 19 articles met the inclusion criteria. Two were specific to pediatric dialysis and three to peritoneal dialysis. Whilst many publications provided recommendations on aerobic exercise, progressive resistance training and flexibility, few provided explicit guidance. Recommendations for the intensity, duration and frequency of aerobic and resistance training varied. Discrepancies or gaps in guidance about precautions, contraindications, termination criteria, progression, and access site precautions were also apparent. CONCLUSION: Future guidelines should include specific guidance regarding physical activity, safety precautions, and timing and intensity of exercise for individuals who undertake dialysis. Collaborative multidisciplinary guideline development and appropriate exercise counselling may lead to increased participation in physical activity and exercise and facilitate better patient outcomes.

Characterization of a Bacterial Kinase That Phosphorylates Dihydrosphingosine to Form dhS1P.

Like other members of the phylum Bacteroidetes, the oral anaerobe Porphyromonas gingivalis synthesizes a variety of sphingolipids, similar to its human host. Studies have shown that synthesis of these lipids (dihydroceramides [DHCs]) is involved in oxidative stress resistance, the survival of P. gingivalis during stationary phase, and immune modulation. Here, we constructed a deletion mutant of P. gingivalis strain W83 with a deletion of the gene encoding DhSphK1, a protein that shows high similarity to a eukaryotic sphingosine kinase, an enzyme that phosphorylates sphingosine to form sphingosine-1-phosphate. Our data show that deletion of the dhSphK1 gene results in a shift in the sphingolipid composition of P. gingivalis cells; specifically, the mutant synthesizes higher levels of phosphoglycerol DHCs (PG-DHCs) than the parent strain W83. Although PG1348 shows high similarity to the eukaryotic sphingosine kinase, we discovered that the PG1348 enzyme is unique, since it preferentially phosphorylates dihydrosphingosine, not sphingosine. Besides changes in lipid composition, the W83 ΔPG1348 mutant displayed a defect in cell division, the biogenesis of outer membrane vesicles (OMVs), and the amount of K antigen capsule. Taken together, we have identified the first bacterial dihydrosphingosine kinase whose activity regulates the lipid profile of P. gingivalis and underlies a regulatory mechanism of immune modulation. IMPORTANCE Sphingoid base phosphates, such as sphingosine-1-phosphate (S1P) and dihydrosphingosine-1-phosphate (dhS1P), act as ligands for S1P receptors, and this interaction is known to play a central role in mediating angiogenesis, vascular stability and permeability, and immune cell migration to sites of inflammation. Studies suggest that a shift in ratio to higher levels of dhS1P in relation to S1P alters downstream signaling cascades due to differential binding and activation of the various S1P receptor isoforms. Specifically, higher levels of dhS1P are thought to be anti-inflammatory. Here, we report on the characterization of a novel kinase in Porphyromonas gingivalis that phosphorylates dihydrosphingosine to form dhS1P.

Cannabis's Link to Schizotypy: Phenomenon, Measurement Bias, or Delusion?

Links between cannabis use and psychosis generate research and media attention. Cannabis users have outscored non-users on the Schizotypal Personality Questionnaire-Brief (SPQ-B) in multiple studies, but previous work suggests that groups do not differ if biased items are removed. The present study examined links between schizotypal personality and cannabis use in a large sample recruited from Amazon's MTurk platform (N = 705). Over 500 participants reported lifetime cannabis exposure. Of those, 259 participants reported current cannabis use, and on average, used 4.53 days per week. Users and non-users failed to differ significantly on total SPQ-B scores or any of the three established subscales. The null results inspired a re-examination of the SPQ-B's factor structure, which identified a novel 3-factor solution (difficulty opening up to others, hyperawareness, and odd or unusual behavior). Only the "odd or unusual behavior" factor showed cannabis-related differences, but a differential item functioning test revealed that one subscale item showed potential bias against users. Removing this item diminished group differences. These results suggest that links between schizotypy and cannabis use require cautious interpretation with careful attention to potential measurement bias. In addition, the SPQ-B might have an alternative factor structure that could help answer important questions in psychopathology.

A Systematic Review of Scope and Consistency of Outcome Measures for Physical Fitness in Chronic Kidney Disease Trials.

INTRODUCTION: Impaired physical fitness is prevalent in people with chronic kidney disease (CKD), associating with an increased risk of mortality, falls, and hospitalization. A plethora of physical fitness outcomes have been reported in randomized trials. This study aimed to assess the scope and consistency of physical fitness outcomes and outcome measures reported in trials in CKD. METHODS: A systematic review of randomized trials reporting physical fitness outcomes in adults with CKD (not requiring kidney replacement therapy) receiving hemodialysis (HD) or peritoneal dialysis and kidney transplant recipients was conducted. Studies were identified from MEDLINE, Embase, and the Cochrane Library from 2000 to 2019. The scope, frequency, and characteristics of outcome measures were categorized and analyzed. RESULTS: From 111 trials, 87 tests/measurements were used to evaluate 30 outcomes measures that reported on 23 outcomes, categorized into five domains of physical fitness: neuromuscular fitness (reported in 76% of trials), exercise capacity (64%), physiological-metabolic (49%), body composition (36%), and cardiorespiratory fitness (30%). Neuromuscular fitness was examined by 37 tests/measurements including the physical function component of questionnaires (27%), one-repetition maximum (9%), and hand-grip strength (9%). Outcome measures were assessed by lab-based (58% of all trials), field-based (31%), and patient-reported measures (11%), and commonly evaluated at 12 (30%), 26 (23%) and 52 weeks (10%), respectively. CONCLUSION: There is large heterogeneity in the reporting of physical fitness outcomes, with inconsistencies particularly in the definitions of outcome measures. Standardization in the assessment of physical fitness will likely improve the comparability of trial outcomes and enhance clinical recommendations.

A Novel Regulation of K-antigen Capsule Synthesis in Porphyromonas gingivalis Is Driven by the Response Regulator PG0720-Directed Antisense RNA.

The periodontal pathogen Porphyromonas gingivalis strain W83 displays at least three different surface glycans, specifically two types of lipopolysaccharides (O-LPS and A-LPS) and K-antigen capsule. Despite the importance of K-antigen capsule to the virulence of P. gingivalis, little is known as to how expression of genes involved in the synthesis of this surface glycan is regulated. The genes required for K-antigen capsule synthesis are located in a locus that encodes a number of transcripts, including an operon (PG0104 to PG0121, generating ~19.4-kb transcript) which contains a non-coding 77-bp inverted repeat (77 bpIR) region near the 5'-end. Previously, we identified a 550-nucleotide antisense RNA molecule (designated asSuGR for antisense Surface Glycan Regulator) encoded within the 77-bpIR element that influences the synthesis of surface glycans. In this study, we demonstrate that the DNA-binding response regulator PG0720 can bind the promoter region of asSuGR and activate expression of asSuGR, indicating that PG0720 may indirectly influence transcript levels of the K-antigen capsule operon expressed from the sense strand. The data show that deletion of the PG0720 gene confers a defect in the presentation of surface polysaccharides compared with the parent strain and quantitative RT-PCR (qPCR) analysis determined that the overall expression of genes involved in K-antigen capsule synthesis were down-regulated in the PG0720 mutant. Furthermore, the defects of the PG0720 deletion mutant were restored by complementation. Importantly, the PG0720 deletion mutant showed reduced virulence. Altogether, our data show that the response regulator PG0720 regulates expression of asSuGR, a trans-acting antisense RNA molecule involved in modulating the production of surface polysaccharides in P. gingivalis strain W83. The data provide further evidence that surface glycans are key virulence determinants and significantly advances our understanding of the molecular mechanisms controlling the synthesis of P. gingivalis K-antigen capsule, a key virulence determinant.

Chlamydial MreB Directs Cell Division and Peptidoglycan Synthesis in Escherichia coli in the Absence of FtsZ Activity.

Cell division is the ultimate process for the propagation of bacteria, and FtsZ is an essential protein used by nearly all bacteria for this function. Chlamydiae belong to a small group of bacteria that lack the universal cell division protein FtsZ but still divide by binary fission. Chlamydial MreB is a member of the shape-determining MreB/Mbl family of proteins responsible for rod shape morphology in Escherichia coliChlamydia also encodes a homolog of RodZ, an MreB assembly cytoskeletal protein that links MreB to cell wall synthesis proteins. We hypothesized that MreB directs cell division in Chlamydia and that chlamydial MreB could replace FtsZ function for cell division in E. coli Overexpression of chlamydial mreB-rodZ in E. coli induced prominent morphological changes with production of large swollen or oval bacteria, eventually resulting in bacterial lysis. Low-level expression of chlamydial mreB-rodZ restored viability of a lethal ΔmreB mutation in E. coli, although the bacteria lost their typical rod shape and grew as rounded cells. When FtsZ activity was inhibited by overexpression of SulA in the ΔmreB mutant of E. coli complemented with chlamydial mreB-rodZ, spherical E. coli grew and divided. Localization studies using a fluorescent fusion chlamydial MreB protein indicated that chlamydial RodZ directs chlamydial MreB to the E. coli division septum. These results demonstrate that chlamydial MreB, in partnership with chlamydial RodZ, acts as a cell division protein. Our findings suggest that an mreB-rodZ-based mechanism allows Chlamydia to divide without the universal division protein FtsZ.IMPORTANCE The study of Chlamydia growth and cell division is complicated by its obligate intracellular nature and biphasic lifestyle. Chlamydia also lacks the universal division protein FtsZ. We employed the cell division system of Escherichia coli as a surrogate to identify chlamydial cell division proteins. We demonstrate that chlamydial MreB, together with chlamydial RodZ, forms a cell division and growth complex that can replace FtsZ activity and support cell division in E. coli Chlamydial RodZ plays a major role in directing chlamydial MreB localization to the cell division site. It is likely that the evolution of chlamydial MreB and RodZ to form a functional cell division complex allowed Chlamydia to dispense with its FtsZ-based cell division machinery during genome reduction. Thus, MreB-RodZ represents a possible mechanism for cell division in other bacteria lacking FtsZ.

Ontogeny and tissue-specific expression of immune-relevant genes in Catla catla (Hamilton).

India is the second largest fish producing country in the world with production of 12.6 million tonnes (mt) in 2017-18, and Indian major carps (IMCs) contribute bulk of this fish production. Catla, Catla catla is the fastest growing species among IMCs. However, the survival rate of catla during larval rearing is normally lower than the other IMCs i.e rohu Labeo rohita, and mrigal Cirrhinus mrigala. Continuous efforts are devoted for the identification of nutritional and environmental requirements of fish larvae in order to reduce hatchery mortalities. However, very little information is available regarding physiology of the immune system, especially during the late larval and juvenile stages. Hence, understanding the ontogenetic development of immune-relevant genes in the larval stages of catla will serve as the markers for the development of immune competence and thereby, will be beneficial in developing effective immune intervention strategies. In the present study, expression profiles of some of the important innate (IL-1ß, IL-10, iNOS and C3) and adaptive immune (RAG-1, Ikaros, IgM and IgZ) genes during ontogenetic developmental stages and in different tissues of catla were investigated using quantitative real-time PCR. The results revealed that immune genes IL-1ß, C3, IgM and IgZ were detected in the unfertilized eggs indicating their maternal inheritance. Immune genes, IL-1ß, IL-10 and iNOS were expressed significantly during initial larval developmental stages whereas C3, RAG-1, Ikaros, IgM and IgZ showed significant expression during advanced stages of larval development in catla i.e. from 23 days post hatch (dph). Study of tissue distribution pattern of the genes indicated that innate immune genes were ubiquitously expressed in different tissues with varying degree of expression, whereas adaptive immune genes were predominantly expressed in lymphoid organs of catla. The information thus generated will improve knowledge on the maturation of the immune system in catla and will aid in deciding the appropriate age for vaccination in this teleost species.

Expression of immune genes in Indian major carp, Catla catla challenged with Flavobacterium columnare.

Columnaris disease, caused by Flavobacterium columnare, is one of the important bacterial diseases responsible for large-scale mortalities in numerous freshwater fishes globally. This disease can cause up to 100% mortality within 24 h of infection and is considered to be a cause of concern for aquaculture industry. Despite being a serious disease, scarce information is available regarding host-pathogen interaction, particularly the modulation of different immune genes in response to F. columnare infection. Therefore, in the present study, an attempt has been made to study expression of important immune regulatory genes, namely IL-1ß, iNOS, INF-γ, IL-10, TGF-ß, C3, MHC-I and MHC-II in gills and kidney of Catla catla following experimental infection with F. columnare. The expression analysis of immune genes revealed that transcript levels of IL-1ß, iNOS, IL-10, TGF-ß, C3 and MHC-I were significantly up-regulated (p < 0.05) in both the organs of the infected catla. IFN-γ and MHC-II were up-regulated in gills of infected catla whereas, both the genes showed down-regulation in kidney. The results indicate that important immune genes of C. catla are modulated following infection with F. columnare. The knowledge thus generated will strengthen the understanding of molecular pathogenesis of F. columnare in Indian major carp C. catla.

Biodegradation kinetic modeling of oxo-biodegradable polypropylene/polylactide/nanoclay blends and composites under controlled composting conditions.

Polypropylene/polylactide/nanoclay blend/composite films with/without pro-oxidants/compatibilizer were prepared and aerobically degraded to measure the CO2 evolution under controlled composting conditions as per ASTM D 5338. A first-order Komilis model in series with a flat lag phase was postulated involving two stages; hydrolysis of solid carbon followed by its rapid mineralization. The first, rate-limiting stage further comprised of three possible parallel paths: the solid hydrolysis of readily, moderately, and slowly hydrolyzable carbon fractions. The model parameters were computed after correlating with the experimental data using nonlinear regression analysis. The results of the model characteristic parameters, un-degraded/hydrolyzable/mineralisable-intermediate carbon kinetics, and degradation curves exhibit two distinct kinetic regimes. The first regime comprising of slowly and moderately hydrolyzable carbon is shown by the first four films without pro-oxidants. This causes low degradability and degradation rate. The second regime comprising of the readily and moderately hydrolyzable carbon is shown by another four films containing pro-oxidants. They exhibit relatively high degradability and degradation rate, which peaks at around 11-14th day in the range of 0.219-0.268% per day. The values of their moderately hydrolyzable carbon fractions and the corresponding hydrolysis rates are significantly higher than that of the first regime. For the first regime, the degradability and degradation rate decreases with increase in the slowly hydrolyzable carbon impervious to microbial attack. Their degradation rate profiles show an absence of growth phase due to the absence of readily hydrolyzable carbon. The rate decreases monotonously starting from the maximum value ranging from 0.043 to 0.180% per day. The approach presented can also be implemented to model and design equipment for other waste biodegradation systems.