Association of lifestyle with valvular heart disease progression and life expectancy among elderly people from different socioeconomic backgrounds.

BACKGROUND: Current cardiovascular prevention strategies are based on studies that seldom include valvular heart disease (VHD). The role of modifiable lifestyle factors on VHD progression and life expectancy among the elderly with different socioeconomic statuses (SES) remains unknown. METHODS: This cohort study included 164,775 UK Biobank participants aged 60 years and older. Lifestyle was determined using a five-factor scoring system covering smoking status, obesity, physical activity, diet, and sleep patterns. Based on this score, participants were then classified into "poor," "moderate," or "ideal" lifestyle groups. SES was classified as high or low based on the Townsend Deprivation Index. The association of lifestyle with major VHD progression was evaluated using a multistate mode. The life table method was employed to determine life expectancy with VHD and without VHD. RESULTS: The UK Biobank documented 5132 incident VHD cases with a mean follow-up of 12.3 years and 1418 deaths following VHD with a mean follow-up of 6.0 years. Compared to those with a poor lifestyle, women and men followed an ideal lifestyle had lower hazard ratios for incident VHD (0.66 with 95% CI, 0.59-0.73 for women and 0.77 with 95% CI, 0.71-0.83 for men) and for post-VHD mortality (0.58 for women, 95% CI 0.46-0.74 and 0.62 for men, 95% CI 0.54-0.73). When lifestyle and SES were combined, the lower risk of incident VHD and mortality were observed among participants with an ideal lifestyle and high SES compared to participants with an unhealthy lifestyle and low SES. There was no significant interaction between lifestyle and SES in their correlation with the incidence and subsequent mortality of VHD. Among low SES populations, 60-year-old women and men with VHD who followed ideal lifestyles lived 4.2 years (95% CI, 3.8-4.7) and 5.1 years (95% CI, 4.5-5.6) longer, respectively, compared to those with poor lifestyles. In contrast, the life expectancy gain for those without VHD was 4.4 years (95% CI, 4.0-4.8) for women and 5.3 years (95% CI, 4.8-5.7) for men when adhering to an ideal lifestyle versus a poor one. CONCLUSIONS: Adopting a healthier lifestyle can significantly slow down the progression from free of VHD to incident VHD and further to death and increase life expectancy for both individuals with and without VHD within diverse socioeconomic elderly populations.

Efficacy of 10%,25% and 50% dextrose in the treatment of hypoglycemia in the emergency department - A randomized controlled study.

INTRODUCTION: Documented symptomatic hypoglycemia is defined as "event during which typical symptoms of hypoglycemia are accompanied by measured blood glucose of ≤70 mg/dL. Most of the studies and recommendations for the unconscious hypoglycemic adult advocate the use of 25 g of glucose as 50 mL of 50% dextrose solution intravenous or 1 mg of intramuscular glucagon. OBJECTIVE: To compare the efficacy and safety of 5 g boluses of 10%, 25% and 50% dextrose in the treatment of hypoglycemic patients presenting to our emergency department. METHODS: This was a randomized controlled single blinded study. Hypoglycemic patients in altered mental status were randomized into three treatment arms to be administered 10%, 25% or 50% dextrose. 5 g aliquots of intravenous 10%,25% or 50% dextrose were administered over 1 min. Time taken to achieve a Glasgow Coma Scale (GCS) of 15 and median total doses (g) were the primary outcomes. RESULTS: Data of 204 patients were analysed in the study. There was no difference in the median time to achieve a GCS of 15 in all three treatment arms (6 min). Total median dose administered in the 10% and 25% groups was lower than 50% (10 g vs 15 g). Proportion of patients who received the maximum dose of 25 g was higher in the 50% group as compared to 10% and 25% groups (12%, 3%, 4%). CONCLUSION: There was no difference in 10% dextrose and 25% dextrose as compared to 50% dextrose in achieving the baseline mental status (or GCS 15) in the treatment of hypoglycemia in the ED.

Therapeutic drug monitoring of Amikacin in hospitalized patients: A pilot study.

Background: Amikacin, an aminoglycoside, is a widely used parenteral antibiotic. Therapeutic drug monitoring (TDM) is recommended for aminoglycosides to avoid toxicity. However, the lack of infrastructure at most places precludes it. This pilot and novel study attempt to estimate the real-world serum levels of Amikacin in hospitalised patients. Methods: Thirty admitted patients, given Amikacin injections, were included in the study. In addition, 15 clinical specimens isolated with gram-negative bacteria were tested for minimum inhibitory concentration (MIC) value of Amikacin. Trough and peak serum levels of Amikacin were estimated by high-pressure liquid chromatography (HPLC). Results: The average MIC value of Amikacin estimated in our laboratory was 3.92 mcg/mL. Peak and trough serum levels of Amikacin ranged from 12.1 to 66.4 mcg/ml and 1.1 to 20.7 mcg/ml, respectively. More than 83% of our patients achieved peak Amikacin levels of 15 mcg/mL, and 37% had trough levels above 5 mcg/mL. These levels are desirable watersheds as per available literature. Conclusion: Trough levels of Amikacin in all cases and a review of dosing according to MIC values are recommended to achieve drug safety and therapeutic efficacy.

Rapid Thrombolysis Protocol: Results from a Before-and-after Study.

Objective: Intravenous thrombolysis within 4.5 hours from time of onset has proven benefit in stroke. Universal standard for the door-to-needle (DTN) time is within 60 minutes from the time of arrival of patients to the emergency department. Our rapid thrombolysis protocol (RTPr) was developed with an aim to reduce the DTN time to a minimum by modifying our stroke post-intervention processes. Materials and methods: This before-and-after study was conducted at a single center on patients who received intravenous thrombolysis in the emergency department. Consecutive patients who were thrombolysed using our RTPr (post-intervention group) were compared to the pre-intervention group who were thrombolysed before the implementation of the protocol. The primary outcomes were DTN time, time to recovery, and modified ranking score (mRS) on discharge. Secondary outcomes were mortality, symptomatic intracerebral hemorrhage, and hospital and intensive care unit length of stay. Results: Seventy-four patients were enrolled in each group. Mean DTN time in pre- and post-intervention group was 56.15 minutes (95% CI 49.98-62.31) and 34.91 minutes (95% CI 29.64-40.17) (p <0.001), respectively. In pre-intervention and post-intervention groups, 43.24% (95% CI 32.57-54.59) and 41.89% (95% CI 31.32-53.26) patients, respectively, showed neurological recovery in 24 hours. About 36.49% (95% CI 26.44-47.87) in pre-intervention group and 54.05% (95% CI 42.78-64.93) in post-intervention group had discharge mRS 0-2. Conclusion: The RTPr can be adapted by clinicians and hospitals to bring down the DTN times and improve outcomes for stroke patients. How to cite this article: Verma A, Sarda S, Jaiswal S, Batra A, Haldar M, Sheikh WR, et al. Rapid Thrombolysis Protocol: Results from a Before-and-after Study. Indian J Crit Care Med 2022;26(5):549-554.

Studies of Phylogeny, Symbiotic Functioning and Ecological Traits of Indigenous Microsymbionts Nodulating Bambara Groundnut (Vigna subterranea L. Verdc) in Eswatini.

Rhizobial microsymbionts of grain legumes are ubiquitous in soils and exhibit a wide range of diversity with respect to colony morphology, genetic variability, biochemical characteristics, and phylogenetic relationships. This study assessed the phylogenetic positions of rhizobial microsymbionts of Bambara groundnut from Eswatini exhibiting variations in morpho-physiology, adaptive characteristics, and N2-fixing efficiency. The isolates' ERIC-PCR profiles revealed the presence of high genetic variation among them. These test isolates also exhibited differences in pH tolerance and IAA production. Multilocus sequence analysis based on the 16S rRNA, atpD, glnII, gyrB, and recA gene sequences of representative test isolates closely aligned them to the type strains of Bradyrhizobium arachidis, B. manausense, B. guangdongense, B. elkanii, and B. pachyrhizi. However, some isolates showed a high divergence from the known reference type strains, indicating that they may represent species yet to be properly characterized and described. Functional characterization in the glasshouse revealed that most of the isolates from the contrasting Agro-ecologies of Eswatini were efficient in N2 fixation, and therefore elicited greater stomatal conductance and photosynthetic rates in the homologous Bambara groundnut. Of the 75 isolates tested, 51% were more effective than the commercial Bradyrhizobium sp. strain CB756, with relative symbiotic effectiveness ranging from 138 to 308%. The findings of this study indicated that the analysis of housekeeping genes and functional traits of Bambara-nodulating microsymbionts can provide a clear view for understanding and predicting rhizobial community structure across environmental gradients.

Increased Length of Stay of Critically Ill Patients in the Emergency Department Associated with Higher In-hospital Mortality.

OBJECTIVES: Emergency department (ED) length of stay (LOS) is defined as the time a patient is registered to the time the patient is shifted to a hospital bed or discharged. Increasing demand for quality emergency care has resulted in increased wait times due to demand and supply mismatch. It is perceived that longer LOS in the ED of critical patients leads to poor outcomes. Our goal was to study the impact of LOS in the ED on the patients who required critical care admissions. METHODS: This was a retrospective study conducted in the ED of a tertiary center. Data were collected using electronic health records (EHR) for patients admitted to the intensive care units (ICUs). Patient's LOS in ED was divided into 0-4, 4-8, 8-12, 12-24, and >24 hours. ED LOS was calculated from the registration time to the time patient was handed over in the ICU. Patients were divided into four categories (1-4) based on their criticality. LOS in ED, mortality, and total hospital LOS were analyzed in the study. RESULTS: Three thousand four hundred and twenty-nine patients were enrolled in the study. Mean age was 62.69 years (95% CI 62.11-63.26). A total of 42.09% (95% CI 40.5-43.8) were Category 1 patients. Overall mortality rate was 52.46% (95% CI 50.79-54.13). LOS of 48.15% (95% CI 46.54-49.88) patients in the ED was between 0 and 4 hours, 19.90% (95% CI 18.62-21.29) between 4 and 8 hours, 8.21% (95% CI 7.35-9.19) between 8 and 12 hours, 15.50% (95% CI 14.34-16.77) between 12 and 24 hours, and 8.13% (95% CI 7.27-9.10) >24 hours. Mortality for LOS of 0-4 hours was 51.30% (95% CI 48.89-53.70), 54.03% (95% CI 50.28-57.73) for 4-8 hours, 48.94% (95% CI 43.16-54.75) for 8-12 hours, 51.50% (95% CI 47.26-55.72) for 12-24 hours, and 60.57% (95% CI 54.73-66.13) for >24 hours. CONCLUSION: We concluded that the longer the critically ill patients are boarded in the ED, the higher is the chance for mortality. Processes should be implemented to ease the throughput from the ED. HOW TO CITE THIS ARTICLE: Verma A, Shishodia S, Jaiswal S, Sheikh WR, Haldar M, Vishen A, et al. Increased Length of Stay of Critically Ill Patients in the Emergency Department Associated with Higher In-hospital Mortality. Indian J Crit Care Med 2021;25(11):1221-1225.

Insights into nitrogen fixing traits and population structure analyses in cowpea (Vigna unguiculata L. Walp) accessions grown in Ghana.

With legumes, symbiotic N2 fixation can meet the species N demand and reduce the over-reliance on chemical fertilizers in tropical regions where N deficiency is a major factor limiting crop yields and increased agricultural sustainability. Therefore, to optimize the use of cowpea (Vigna unguiculata L. Walp) germplasm in effective breeding, evaluation of genetic diversity and quantification of N2 fixation are essential prerequisites. The aim of this study was to explore the level of diversity using SSR markers and N2-fixing traits in a set of cowpea germplasm grown in Ghana. We analysed 49 cowpea accessions collected from Northern Ghana using qualitative vegetative and N2 fixation traits, and simple sequence repeat (SSR) markers. Experimental field results revealed considerable morpho-physiological variation for plant growth habits, grain yield and symbiotic performance between and among the cowpea accessions. Results from both the 15N natural abundance and ureides in the xylem sap were able to descriminate between high and low levels of N2 fixation in cowpea accessions. Five subpopulations were identified within accessions inferred from STRUCTURE 2.3.4. A general linear model was used to assess the association of SSR markers with N2-fixing traits. There were significant (p ≤ 0.05) links between SSR markers and symbiosis-related traits such as nodule number, nodule dry weight, shoot dry weight, N-fixed, N derived from air (Ndfa), and relative uried-N (RU-N).

Interrater Reliability of Four Neurological Scales for Patients Presenting to the Emergency Department.

BACKGROUND: Altered mental status (AMS) comprises a group of clinical symptoms rather than a specific diagnosis. A variety of neurological scales have been used to monitor these patients, including the Glasgow coma scale (GCS), AVPU (alert, responds to verbal stimuli, responds to painful stimuli, unresponsive) scale, and ACDU (alert, confused, drowsy, unresponsive) scale. The simplified motor scale (SMS) has been found to be a potential replacement for the GCS. In this study, we compare the interrater reliability of the GCS (individual components), AVPU, ACDU, and SMS to patients presenting to the ED with AMS. MATERIALS AND METHODS: This was a prospective observational study conducted in the emergency department of an urban tertiary-care hospital in New Delhi, India. Patients with AMS (traumatic and nontraumatic) presenting to the ED were assessed by two emergency physicians within 10 minutes of each other using the four neurological scales. Percentage agreement and kappa coefficient score were used to determine interrater reliability for SMS, individual components of GCS, AVPU, and ACDU. RESULTS: The SMS had the best inter-rater percent agreement with 83.91% (95% CI 77.7-88.6%), followed by ACDU which was 76.44% (95% CI 69.0-81.6%), AVPU 75.29% (95% CI 67.8-80.6%), GCS Eye 74.14% (95% CI 66.6-79.6%), GCS Verbal 67.82% (95% CI 60.6-74.3%), and GCS Motor was 64.94% (95% CI 57.6-71.6%).The kappa coefficient for SMS was 0.75 (95% CI 0.67-0.83), followed by GCS Eye which was 0.63 (95% CI 0.54-0.72), AVPU 0.62 (95% CI 0.52-0.72), ACDU 0.60 (95% CI 0.49-0.71), and GCS Verbal 0.58 (0.49-0.66) and GCS Motor was 0.53 (95% CI 0.44-0.63). CONCLUSION: It can be said that SMS has the best interrater reliability in the ED and can be recommended for clinical use in the emergency departments for patients presenting with AMS. HOW TO CITE THIS ARTICLE: Haldar M, Verma A, Jaiswal S, Sheikh WR. Interrater Reliability of Four Neurological Scales for Patients Presenting to the Emergency Department. Indian J Crit Care Med 2020;24(12):1198-1200.

Reply to in Response to Guidewire Entrapped in the Right Ventricle.

How to cite this article: Verma A, Jaiswal S, Vishen A, Sheikh WR, Haldar M, Ahuja R, et al. Reply to in Response to Guidewire Entrapped in the Right Ventricle. Indian J Crit Care Med 2020;24(7):608.

Guidewire Entrapped in the Right Ventricle: A Rare Complication of Hemodialysis Catheter Insertion.

How to cite this article: Verma A, Chitransh V, Jaiswal S, Vishen A, Sheikh WR, Haldar M, et al. Guidewire Entrapped in the Right Ventricle: A Rare Complication of Hemodialysis Catheter Insertion. Indian J Crit Care Med 2020;24(1):80-81.

Insights into the Phylogeny, Nodule Function, and Biogeographic Distribution of Microsymbionts Nodulating the Orphan Kersting's Groundnut [Macrotyloma geocarpum (Harms) Marechal & Baudet] in African Soils.

Kersting's groundnut [Macrotyloma geocarpum (Harms) Marechal & Baudet] is a neglected indigenous African legume adapted to growth in N-deficient soils due to its ability to fix atmospheric N2 via symbiosis with rhizobia. Despite its nutritional and medicinal uses, to date there is little information on the phylogeny and functional traits of its microsymbionts, aspects that are much needed for its conservation and improvement. This study explored the morphogenetic diversity, phylogenetic relationships, and N2-fixing efficiency of Kersting's groundnut rhizobial isolates from contrasting environments in Ghana, South Africa, and Mozambique. BOX-PCR fingerprinting revealed high diversity among the rhizobial populations, which was influenced by geographic origin. Of the 164 isolates evaluated, 130 BOX-PCR types were identified at a 70% similarity coefficient, indicating that they were not clones. Soil pH and mineral concentrations were found to influence the distribution of bradyrhizobial populations in African soils. Phylogenetic analysis of 16S rRNA genes and multilocus sequence analysis of protein-coding genes (atpD, glnII, gyrB, and rpoB) and symbiotic genes (nifH and nodC) showed that Kersting's groundnut is primarily nodulated by members of the genus Bradyrhizobium, which are closely related to Bradyrhizobium vignae 7-2T, Bradyrhizobium kavangense 14-3T, Bradyrhizobium subterraneum 58-2-1T, Bradyrhizobium pachyrhizi PAC48T, the type strain of Bradyrhizobium elkanii, and novel groups of Bradyrhizobium species. The bradyrhizobial populations identified exhibited high N2 fixation and induced greater nodulation, leaf chlorophyll concentration, and photosynthetic rates in their homologous host than did the 5 mM KNO3-fed plants and/or the commercial Bradyrhizobium sp. strain CB756, suggesting that they could be good candidates for inoculant formulations upon field testing.IMPORTANCE Rhizobia play important roles in agroecosystems, where they contribute to improving overall soil health through their symbiotic relationship with legumes. This study explored the microsymbionts nodulating Kersting's groundnut, a neglected orphan legume. The results revealed the presence of different bradyrhizobial populations with high N2-fixing efficiencies as the dominant symbionts of this legume across diverse agroecologies in Africa. Our findings represent a useful contribution to the literature in terms of the community of microsymbionts nodulating a neglected cultivated legume and its potential for elevation as a major food crop. The presence of potentially novel bradyrhizobial symbionts of Kersting's groundnut found in this study offers an opportunity for future studies to properly describe, characterize, and delineate these isolates functionally and phylogenetically for use in inoculant production to enhance food/nutritional security.

Microbial community structure in the rhizosphere of the orphan legume Kersting's groundnut [Macrotyloma geocarpum (Harms) Marechal & Baudet].

The presence of microbial communities in the rhizosphere of plants is an important determinant of plant health and soil organic matter composition. Plant species play significant roles in selecting the specific microbial communities that inhabit the root zone. However, till now, there is no solid information regarding the presence of specific plant-microbiome in the rhizosphere of many plants, especially under-exploited and under-researched species such as Kersting's groundnut. This study assessed the effect of five Kersting's groundnut landraces on the structure of microbial communities in rhizosphere of field-grown plants. The five tested Kersting's groundnut landraces (Belane Mottled, Boli, Funsi, Puffeun and Heng Red Mottled) were found to exert a marked selective influence on bacteria associated with their rhizospheres, measured using 16S rDNA MiSeq illumina sequencing. Community differences in microbial composition and relative abundance were both significant. Numerous phyla in the rhizosphere were affected by the test landraces. Except for Belane mottled whose rhizospheres were dominated by Proteobacteria, the rhizosphere soils of the other landraces were dominated by Bacteroidetes. With the exception of landrace Puffeun which showed only Mesorhizobium in its rhizosphere, all the other test landraces revealed the presence of Bradyrhizobium and Rhizobium species of alpha Proteobacteria. Furthermore, the rhizosphere of all landraces were abundant in species of the indole-3-acetic-acid producing Sphingomonas and cellulose-degrading Fibrobacteres. The results of this study suggest that Kersting's groundnut landraces can shape bacterial community composition in the rhizosphere via plant-related changes in the rhizosphere soil.

HF-SENSE: an improved partially parallel imaging using a high-pass filter.

BACKGROUND: One of the major limitations of MRI is its slow acquisition speed. To accelerate data acquisition, partially parallel imaging (PPI) methods have been widely used in clinical applications such as sensitivity encoding (SENSE) and generalized autocalibrating partially parallel acquisitions (GRAPPA). SENSE is a popular image-domain partially parallel imaging method, which suffers from residual aliasing artifacts when the reduction factor goes higher. Undersampling the k-space data and then reconstruct images with artificial sparsity is an efficient way to accelerate data acquisition. By exploiting artificial sparsity with a high-pass filter, an improved SENSE method is proposed in this work, termed high-pass filtered SENSE (HF-SENSE). METHODS: First, a high-pass filter was applied to the raw k-space data, the result of which was used as the inputs of sensitivity estimation and undersampling process. Second, the adaptive array coil combination method was adopted to calculate sensitivity maps on a block-by-block basis. Third, Tikhonov regularized SENSE was then used to reconstruct magnetic resonance images. Fourth, the reconstructed images were transformed into k-space data, which was filtered with the corresponding inverse filter. RESULTS: Both simulation and in vivo experiments demonstrate that HF-SENSE method significantly reduces noise level of the reconstructed images compared with SENSE. Furthermore, it is found that HF-SENSE can achieve lower normalized root-mean-square error value than SENSE. CONCLUSIONS: The proposed method explores artificial sparsity with a high-pass filter. Experiments demonstrate that the proposed HF-SENSE method can improve the image quality of SENSE reconstruction. The high-pass filter parameters can be predefined. With this image reconstruction method, high acceleration factors can be achieved, which will improve the clinical applicability of SENSE. This retrospective study (HF-SENSE: an improved partially parallel imaging using a high-pass filter) was approved by Institute Review Board of 2nd Affiliated Hospital of Zhejiang University (ethical approval number 2018-314). Participant for all images have informed consent that he knew the risks and agreed to participate in the research.

Ketamine Use allows Noninvasive Ventilation in Distressed Patients with Acute Decompensated Heart Failure.

Acute decompensated heart failure (ADHF) is responsible for a heavy clinical load on busy emergency departments (EDs) across the globe and especially in India. ADHF patients may present with severe respiratory distress, dyspnea, hypoxia, and high and low blood pressures. Managing the airway of such patients can at times be challenging. Nasal cannulae, face mask, and noninvasive positive pressure ventilation (NIPPV) are the cornerstones of providing oxygenation and ventilation to such patients while some extreme cases may require endotracheal intubation and mechanical ventilation. An elderly female in severe respiratory distress and altered sensorium presented to our ED and had to be administered ketamine to facilitate proper NIPPV and avoid mechanical ventilation. She was weaned off the NIPPV in the ED itself over the next four hours. There are some case reports of using ketamine for NIPPV in asthma exacerbations, but none for the use in ADHF. Avoiding invasive mechanical ventilation via endotracheal intubation should be a constant goal and the last resort. How to cite this article: Verma A, Snehy A, et al. Ketamine Use Allows Noninvasive Ventilation in Distressed Patients with Acute Decompensated Heart Failure. Indian J Crit Care Med 2019;23(4): 191-192.

Distribution and Phylogeny of Microsymbionts Associated with Cowpea (Vigna unguiculata) Nodulation in Three Agroecological Regions of Mozambique.

Cowpea derives most of its N nutrition from biological nitrogen fixation (BNF) via symbiotic bacteroids in root nodules. In Sub-Saharan Africa, the diversity and biogeographic distribution of bacterial microsymbionts nodulating cowpea and other indigenous legumes are not well understood, though needed for increased legume production. The aim of this study was to describe the distribution and phylogenies of rhizobia at different agroecological regions of Mozambique using PCR of the BOX element (BOX-PCR), restriction fragment length polymorphism of the internal transcribed spacer (ITS-RFLP), and sequence analysis of ribosomal, symbiotic, and housekeeping genes. A total of 122 microsymbionts isolated from two cowpea varieties (IT-1263 and IT-18) grouped into 17 clades within the BOX-PCR dendrogram. The PCR-ITS analysis yielded 17 ITS types for the bacterial isolates, while ITS-RFLP analysis placed all test isolates in six distinct clusters (I to VI). BLASTn sequence analysis of 16S rRNA and four housekeeping genes (glnII, gyrB, recA, and rpoB) showed their alignment with Rhizobium and Bradyrhizobium species. The results revealed a group of highly diverse and adapted cowpea-nodulating microsymbionts which included Bradyrhizobium pachyrhizi, Bradyrhizobium arachidis, Bradyrhizobium yuanmingense, and a novel Bradyrhizobium sp., as well as Rhizobium tropici, Rhizobium pusense, and Neorhizobium galegae in Mozambican soils. Discordances observed in single-gene phylogenies could be attributed to horizontal gene transfer and/or subsequent recombinations of the genes. Natural deletion of 60 bp of the gyrB region was observed in isolate TUTVU7; however, this deletion effect on DNA gyrase function still needs to be confirmed. The inconsistency of nifH with core gene phylogenies suggested differences in the evolutionary history of both chromosomal and symbiotic genes.IMPORTANCE A diverse group of both Bradyrhizobium and Rhizobium species responsible for cowpea nodulation in Mozambique was found in this study. Future studies could prove useful in evaluating these bacterial isolates for symbiotic efficiency and strain competitiveness in Mozambican soils.

Transcatheter Aortic Valve Replacement for Pure Native Aortic Valve Regurgitation: A Systematic Review.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is a recent and an effective treatment option for high- or extreme-surgical-risk patients with symptomatic severe aortic stenosis. However, pure severe native aortic valve regurgitation (NAVR) without aortic stenosis remains a contraindication to TAVR. The aim of our systemic review analysis was to evaluate TAVR in patients with pure NAVR. METHODS: We searched the published articles in the PubMed and Web of Science databases (2002-2017) using the Boolean operators for studies of NAVR patients undergoing TAVR. Reference lists of all returned articles were searched recursively for other relevant citations. Pooled estimates were calculated using a random-effects meta-analysis. RESULTS: Finally, a total of 10 studies were included in this analysis. The CoreValve was more frequently used with a lower rate of device success and a higher rate of residual aortic regurgitation. The new-generation transcatheter heart valves (THVs) performed a significantly higher rate with less residual aortic regurgitation and a success rate close to 100%. The 30-day all-cause mortality rates ranged from 0 to 30% with an estimate summary rate of 9% (95% CI: 5-15%; I2 = 33%). Cerebrovascular events, major or life-threatening bleeding, major vascular complications, acute kidney disease, and new permanent pacemaker implantation occurred similarly in both the new- and old-generation THV devices. CONCLUSIONS: Aortic regurgitation remains a challenging pathology for TAVR. TAVR is a feasible and reasonable option for carefully selected patients with pure aortic regurgitation.

Assessing host range, symbiotic effectiveness, and photosynthetic rates induced by native soybean rhizobia isolated from Mozambican and South African soils.

Host range and cross-infectivity studies are important for identifying rhizobial strains with potential for use as inoculants. In this study, 10 native soybean rhizobia isolated from Mozambican and South African soils were evaluated for host range, symbiotic effectiveness and ability to induce high rates of photosynthesis leading to enhanced plant growth in cowpea (Vigna unguiculata L. Walp.), Bambara groundnut (Vigna subterranean L. Verdc.), Kersting's groundnut (Macrotyloma geocarpum Harm) and soybean (Glycine max L. Merr). The test isolates had different growth rates and colony sizes. Molecular analysis based on enterobacterial repetitive intergenic consensus (ERIC)-PCR revealed high genetic diversity among the test isolates. The results further showed that isolate TUTLBC2B failed to elicit nodulation in all test plants, just as TUTNSN2A and TUTDAIAP3B were also unable to nodulate cowpea, Kersting's bean and Bambara groundnut. Although the remaining strains formed ineffective nodules on cowpea and Kersting's bean, they induced effective nodules on Bambara groundnut and the two soybean genotypes. Bacterial stimulation of nodule numbers, nodule dry weights and photosynthetic rates was generally greater with isolates TUTRSRH3A, TUTM19373A, TUTMCJ7B, TUTRLR3B and TUTRJN5A. As a result, these isolates elicited significantly increased accumulation of biomass in shoots and whole plants of Bambara groundnut and the two soybean genotypes. Whole-plant symbiotic nitrogen (N) of soybean and Bambara groundnut was highest for the commercial strains CB756 and WB74, as well as for TUTRLR3B, TUTMCJ7B and TUTRSRH3A, suggesting that the three native rhizobial isolates have potential for use as inoculants.

Antibiotics Resistance in Rhizobium: Type, Process, Mechanism and Benefit for Agriculture.

The use of high-quality rhizobial inoculants on agricultural legumes has contributed substantially to the N economy of farming systems through inputs from biological nitrogen fixation (BNF). Large populations of symbiotically effective rhizobia should be available in the rhizosphere for symbiotic BNF with host plants. The rhizobial populations should also be able to compete and infect host plants. However, the rhizosphere comprises large populations of different microorganisms. Some of these microorganisms naturally produce antibiotics which are lethal to susceptible rhizobial populations in the soil. Therefore, intrinsic resistance to antibiotics is a desirable trait for the rhizobial population. It increases the rhizobia's chances of growth, multiplication and persistence in the soil. With a large population of rhizobia in the soil, infectivity of host plants and the subsequent BNF efficiency can be guaranteed. This review, therefore, puts together findings by various researchers on antibiotic resistance in bacteria with the main emphasis on rhizobia. It describes the different modes of action of different antibiotics, the types of antibiotic resistance exhibited by rhizobia, the mechanisms of acquisition of antibiotic resistance in rhizobia and the levels of tolerance of different rhizobial species to different antibiotics.

Identification and characterization of phages parasitic on bradyrhizobia nodulating groundnut (Arachis hypogaea L.) in South Africa.

In this study, three lytic phages (namely, PRSA-1, PRSA-2 and PRSA-26) were isolated and characterized for their morphology, host range, profile and restriction endonuclease banding pattern of genome size. The susceptible rhizobial isolates were identified by nifH and glnII sequence analysis. The results showed that all phages had polyhedral head with non-contractile tail which confirmed their relationship with the Siphoviridae family. All the three phages produced highly distinct plaques on their host bradyrhizobial lawn, and were highly sensitive to chloroform. The phage genome sizes ranged from 34.7 to 53.1 kbp. The phages were tested against groundnut-nodulating bradyrhizobial strains TUTAHSA75, TUTAHSA155 and TUTAHSA126 isolated from South African soils. The results revealed different bacterial susceptibilities to phages. Bradyrhizobial isolate TUTAHSA126 was susceptible to all three phages (i.e. PRSA-1, PRSA-2 and PRSA-26), TUTAHSA155 to two phages (i.e. PRSA-1, PRSA-2), and TUTAHSA75 to only one phage (i.e. PRSA-1). Phylogenetic analysis of nifH and glnII gene sequences of the phage-susceptible bradyrhizobial isolates revealed their close relatedness to a diverse group of Bradyrhizobium species. Phage PRSA-1 could parasitize on all three bradyrhizobial strains, which indicates its potential role in horizontal gene transfer through lysogenic conversion, and/or genetic transduction in soil microbial environments.

Seed-Coat Pigmentation Plays a Crucial Role in Partner Selection and N2 Fixation in Legume-Root-Microbe Associations in African Soils.

Legume-rhizobia symbiosis is the most important plant-microbe interaction in sustainable agriculture due to its ability to provide much needed N in cropping systems. This interaction is mediated by the mutual recognition of signaling molecules from the two partners, namely legumes and rhizobia. In legumes, these molecules are in the form of flavonoids and anthocyanins, which are responsible for the pigmentation of plant organs, such as seeds, flowers, fruits, and even leaves. Seed-coat pigmentation in legumes is a dominant factor influencing gene expression relating to N2 fixation and may be responsible for the different N2-fixing abilities observed among legume genotypes under field conditions in African soils. Common bean, cowpea, Kersting's groundnut, and Bambara groundnut landraces with black seed-coat color are reported to release higher concentrations of nod-gene-inducing flavonoids and anthocyanins compared with the Red and Cream landraces. Black seed-coat pigmentation is considered a biomarker for enhanced nodulation and N2 fixation in legumes. Cowpea, Bambara groundnut, and Kersting's bean with differing seed-coat colors are known to attract different soil rhizobia based on PCR-RFLP analysis of bacterial DNA. Even when seeds of the same legume with diverse seed-coat colors were planted together in one hole, the nodulating bradyrhizobia clustered differently in the PCR-RFLP dendrogram. Kersting's groundnut, Bambara groundnut, and cowpea with differing seed-coat colors were selectively nodulated by different bradyrhizobial species. The 16S rRNA amplicon sequencing also found significant selective influences of seed-coat pigmentation on microbial community structure in the rhizosphere of five Kersting's groundnut landraces. Seed-coat color therefore plays a dominant role in the selection of the bacterial partner in the legume-rhizobia symbiosis.