Rhizobial bacteria are commonly found in soil but also establish symbiotic relationships with legumes, inhabiting the root nodules, where they fix nitrogen. Endophytic rhizobia have also been reported in the roots and stems of legumes and other plants. We isolated several rhizobial strains from the nodules of noninoculated bean plants and looked for their provenance in the interiors of the seeds. Nine isolates were obtained, covering most known bean symbiont species, which belong to the Rhizobium and Sinorhizobium groups. The strains showed several large plasmids, except for a Sinorhizobium americanum isolate. Two strains, one Rhizobium phaseoli and one S. americanum strain, were thoroughly characterized. Optimal symbiotic performance was observed for both of these strains. The S. americanum strain showed biotin prototrophy when subcultured, as well as high pyruvate dehydrogenase (PDH) activity, both of which are key factors in maintaining optimal growth. The R. phaseoli strain was a biotin auxotroph, did not grow when subcultured, accumulated a large amount of poly--hydroxybutyrate, and exhibited low PDH activity. The physiology and genomes of these strains showed features that may have resulted from their lifestyle inside the seeds: stress sensitivity, a ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) complex, a homocitrate synthase (usually present only in free-living diazotrophs), a hydrogenase uptake cluster, and the presence of prophages. We propose that colonization by rhizobia and their presence in Phaseolus seeds may be part of a persistence mechanism that helps to retain and disperse rhizobial strains. Bacteria can populate diverse environments, from soil to water, even in the most extreme sites on the earth. These organisms can also be found on and inside other organisms, such as fungi, animals, and plants. The microbiome is a recently developed concept used to define the prokaryotic populations in close relationship with more-complex organisms (1, 2). Bacteria can flourish as endophytes inside plant roots, stems, leaves, and seeds (3) in crops (e.g., wheat, rice, maize, sorghum, and sugarcane), legumes (e.g., clover, common bean, and alfalfa), trees (e.g., Populus), grasses (e.g., switchgrass), and model plants (e.g., Arabidopsis) (4). Most common endophytic bacterial species have been described as members of the phyla Firmicutes and Proteobacteria (5).Legumes are economically valuable plants in agriculture and establish symbiotic relationships with rhizobial bacteria (6). These bacteria contribute to the formation of plant root nodules, colonizing them and fixing atmospheric nitrogen. This phenomenon has been studied intensively (7). Endophytic rhizobia, in tissues other than nodules, have also been isolated from clover and pea (e.g., Rhizobium phaseoli and Rhizobium leguminosarum bv. trifolii) (8). Several nonrhizobial bacterial species have been isolated from Phaseolus tissues (roots, stems, and seeds); these include Acinetobacter, Bacillus, Enterococcus, Nocardioides, Paracoccus, Phyll...
ABSTRACT.Objective: To compare the clinical efficacy and tolerance of 0.1% olopatadine hydrochloride (OHC) versus 0.05% ketotifen fumarate (KF) in the management of allergic conjunctivitis. Materials and Methods: Eighty adult patients with a history of allergy (allergic conjunctivitis, hay fever, asthmatic bronchitis and dermatitis) that were showing allergic conjunctivitis signs and symptoms (itching, hyperemia, mucous discharge and tearing) at the time of inclusion in this study were evaluated. Patients were divided in two groups, A and B. Group A patients were treated with OHC and group B patients were treated with KF. Both groups received one drop in the affected eye every 12 hrs. The start time of this study was the first patient visit, in which the medication was instilled for the first time. Both groups of patients were evaluated 30 min, 48 hr., 7 days and 14 days later. Local tolerance of each medication was evaluated. Results: Clinical improvement of the signs and symptoms of allergic conjunctivitis occurred in 42.5% to 62.5% of the patients in Group A when assessed 30 min following the first topical ocular dose of olopatadine. However, mucous discharge was not affected. Forty-eight (48) hrs. after the first instillation, improvements in 57.5% to 75% of the patients were shown in every evaluated parameter. After 7 days of treatment, positive clinical results were observed in 80% to 87.5% of the treated patients. Except for the patients that were dismissed from the study before the seventh day of treatment due to the absence of therapeutic response (4/40), all patients satisfactorily completed the therapeutic plan by the seventh day. No intolerance reactions were observed in patients of this group. In Group B patients (KF), clinical improvement of the signs and symptoms measured in the study was shown in 20.0% to 47.5% 30 min after instillation. As observed with olopatadine, no improvement in the number of patients showing mucous discharge was noted at the 30-min time point. At 48 hr. after the first instillation, 27.5% to 48% of patients showed improvement in every evaluated parameter. After 7 days of treatment, improvement was observed in 60% to 75% of patients. On Day 14, positive responses were observed in 67.5% to 75% of patients. Seventeen and one-half percent of the patients were dismissed from the study before the seventh day of treatment due to the absence of a therapeutic response. Approximately 23% of the patients had mild reactions of intolerance (stinging) which was not a cause to discontinue the treatment. Conclusion: Olopatadine hydrochloride controlled allergic conjunctivitis symptoms and signs more rapidly and to a greater extent than ketotifen fumarate. A O S 2000 53Fewer cases of treatment failure were noted with OHC, and no local intolerance reactions were observed, while KF triggered mild reactions (stinging) in 23% of patients.
PurposeTo evaluate the ability of Systane® Balance (SYSB) administered four times per day for 4 weeks to increase noninvasive tear film break-up time (NITFBUT) over baseline compared with a saline (SAL) control in patients with lipid-deficient dry eye (DE).Patients and methodsPatients aged ≥18 years with DE and evidence of meibomian gland dysfunction (ie, abnormal gland expression and missing meibomian glands) were included in this randomized, parallel-group, controlled, investigator-masked comparison study. Patients were randomized to SYSB or SAL four times daily for 4 weeks. The primary efficacy variable was mean change in NITFBUT from baseline at week 4. Ocular surface staining, goblet cell density, and meibomian gland expression were also assessed. Safety assessments included adverse events (AEs), best-corrected visual acuity, and ocular signs.ResultsA total of 49 patients received study treatments (SYSB, n=25; SAL, n=24). Most patients were women (67.4%) and Caucasian (63.3%); mean ± standard deviation (SD) age was 44±19 years. DE characteristics at baseline were similar between groups. After 4 weeks of treatment, the mean ± SD NITFBUT increase from baseline was significantly greater with SYSB (2.83±0.74 seconds) compared with SAL (0.66±0.55 seconds; P<0.001, t-test). Improvements in conjunctival and corneal staining, percentage of patients with increased goblet cell density, and meibomian gland expression were also observed with 4 weeks of SYSB over SAL. No AEs were reported for either treatment group; best-corrected visual acuity and ocular signs remained stable or improved compared with baseline.ConclusionSYSB restored tear film stability, improved ocular surface healing, and improved meibomian gland functionality after 4 weeks of use in patients with lipid-deficient DE. No AEs were reported with either SYSB or SAL.
BackgroundComparative genomics has provided valuable insights into the nature of gene sequence variation and chromosomal organization of closely related bacterial species. However, questions about the biological significance of gene order conservation, or synteny, remain open. Moreover, few comprehensive studies have been reported for rhizobial genomes.ResultsWe analyzed the genomic sequences of four fast growing Rhizobiales (Sinorhizobium meliloti, Agrobacterium tumefaciens, Mesorhizobium loti and Brucella melitensis). We made a comprehensive gene classification to define chromosomal orthologs, genes with homologs in other replicons such as plasmids, and those which were species-specific. About two thousand genes were predicted to be orthologs in each chromosome and about 80% of these were syntenic. A striking gene colinearity was found in pairs of organisms and a large fraction of the microsyntenic regions and operons were similar. Syntenic products showed higher identity levels than non-syntenic ones, suggesting a resistance to sequence variation due to functional constraints; also, an unusually high fraction of syntenic products contained membranal segments. Syntenic genes encode a high proportion of essential cell functions, presented a high level of functional relationships and a very low horizontal gene transfer rate. The sequence variability of the proteins can be considered the species signature in response to specific niche adaptation. Comparatively, an analysis with genomes of Enterobacteriales showed a different gene organization but gave similar results in the synteny conservation, essential role of syntenic genes and higher functional linkage among the genes of the microsyntenic regions.ConclusionSyntenic bacterial genes represent a commonly evolved group. They not only reveal the core chromosomal segments present in the last common ancestor and determine the metabolic characteristics shared by these microorganisms, but also show resistance to sequence variation and rearrangement, possibly due to their essential character. In Rhizobiales and Enterobacteriales, syntenic genes encode a high proportion of essential cell functions and presented a high level of functional relationships.
Pharmacological studies have shown that sumatriptan, a selective ligand of the serotonin 5-HT-1Dbeta autoreceptor, modifies obsessive-compulsive disorder (OCD) symptoms. The current study analysed the G861C polymorphism of the 5-HT-1Dbeta gene in a sample of 72 trios. Genotyping data were analysed using the Family-Based Association Test (FBAT). We did not replicate the previously reported linkage disequilibrium between the G861 variant and OCD. However, a quantitative trait analysis, assessing severity of OCD symptoms and defined as YBOCS score, confirmed the finding that subjects with a preferential transmission of the G861 variant showed higher YBOCS Obsession scores compared to patients carrying the C861 allele. These preliminary findings may indicate that the 5-HT-1Dbeta receptor gene could be involved in the severity of obsession symptoms in OCD. However, it is important to perform the replication of these findings in larger sample sizes of informative families.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.