OsBTBZ1 Confers Salt Stress Tolerance in Arabidopsis thaliana.

Rice (Oryza sativa L.), one of the most important commodities and a primary food source worldwide, can be affected by adverse environmental factors. The chromosome segment substitution line 16 (CSSL16) of rice is considered salt-tolerant. A comparison of the transcriptomic data of the CSSL16 line under normal and salt stress conditions revealed 511 differentially expressed sequence (DEseq) genes at the seedling stage, 520 DEseq genes in the secondary leaves, and 584 DEseq genes in the flag leaves at the booting stage. Four BTB genes, OsBTBZ1, OsBTBZ2, OsBTBN3, and OsBTBN7, were differentially expressed under salt stress. Interestingly, only OsBTBZ1 was differentially expressed at the seedling stage, whereas the other genes were differentially expressed at the booting stage. Based on the STRING database, OsBTBZ1 was more closely associated with other abiotic stress-related proteins than other BTB genes. The highest expression of OsBTBZ1 was observed in the sheaths of young leaves. The OsBTBZ1-GFP fusion protein was localized to the nucleus, supporting the hypothesis of a transcriptionally regulatory role for this protein. The bt3 Arabidopsis mutant line exhibited susceptibility to NaCl and abscisic acid (ABA) but not to mannitol. NaCl and ABA decreased the germination rate and growth of the mutant lines. Moreover, the ectopic expression of OsBTBZ1 rescued the phenotypes of the bt3 mutant line and enhanced the growth of wild-type Arabidopsis under stress conditions. These results suggest that OsBTBZ1 is a salt-tolerant gene functioning in ABA-dependent pathways.

Prognostic Significance of Pre-Discharge Plasma BNP among Heart Failure Patients in Ilorin, Nigeria.

INTRODUCTION: Although the usefulness of plasma brain natriuretic peptide (BNP) in early diagnosis of heart failure has been extensively studied, its value in predicting outcome of these patients has not been fully determined, particularly among African patients. OBJECTIVE: This study was aimed to evaluating the prognostic implications of pre-discharge BNP among hospitalized heart failure patients in Nigeria. METHODS: One hundred consecutive acutely decompensated heart failure patients managed in our center were recruited into the study. All subjects had clinical and echocardiographic evaluation. All had BNP assayed and were followed-up for six months. RESULTS: Fifteen patients (out of 91 who completed the study) died at the end of the study, giving a 6-month mortality rate of 16.5%. The mean BNP among non-survivors (655.0 ± 142.3pg/ml) was higher than survivors (409.7±178.2pg/ml) P <0.001. A plasma BNP level >525pg/ml was 87% sensitive and 75% specific for predicting death within 6-months (AUC0.854,95% CI 0.756-0.951, p<0.001). Kaplan-Meier survival curve also showed six-month survival to be significantly reduced in patients discharged with BNP levels >525pg/ml (57.6%) than in those with levels <525pg/ml (98.3%), p<0.001. CONCLUSION: Pre-discharge plasma BNP>525pg/ml in heart failure patients is predictive of early death within six months.

INTRODUCTION: Bien que l'utilité du peptide natriurétique plasma-cerveau (BNP) dans le diagnostic précoce de l'insuffisance cardiaque ait été largement étudiée, sa valeur pour prédire l'issue de ces patients n'a pas été entièrement déterminée, en particulier chez les patients africains. OBJECTIF: Cette étude visait à évaluer les implications pronostiques du BNP avant la sortie chez les patients hospitalisés pour insuffisance cardiaque au Nigeria. MÉTHODES: Cent patients consécutifs atteints d'insuffisance cardiaque en décompensation aiguë, pris en charge dans notre centre, ont été recrutés dans l'étude. Tous les sujets ont eu une évaluation clinique et échocardiographique. Tous avaient un dosage du BNP et ont été suivis pendant six mois. RÉSULTATS: Quinze patients (sur 91 ayant terminé l'étude) sont décédés à la fin de l'étude, ce qui donne un taux de mortalité à 6 mois de 16,5 %. Le BNP moyen parmi les non-survivants (655,0 ± 142,3 pg/ml) était supérieur à celui des survivants (409,7± 178,2 pg/ml) P < 0,001. Un taux plasmatique de BNP > 525 pg/ml était sensible à 87 % et spécifique à 75 % pour prédire le décès dans les 6 mois (ASC 0,854, IC à 95 % 0,756-0,951, p <0,001). La courbe de survie de Kaplan-Meier a également montré que la survie à six mois était significativement réduite chez les patients sortis avec des taux de BNP > 525 pg/ml (57,6 %) que chez ceux avec des taux < 525 pg/ml (98,3 %), p < 0,001. CONCLUSION: Le BNP plasmatique avant la sortie > 525 pg/ml chez les patients insuffisants cardiaques est prédictif d'un décès précoce dans les six mois. Mots clés: Insuffisance cardiaque décompensée aiguë, pronostic, peptide natriurétique cérébral, mortalité, Nigérians.

KNOWLEDGE, RISK PERCEPTION AND PREVENTIVE PRACTICES OF COVID-19 AMONG STAFF OF PRIMARY AND SECONDARY SCHOOLS IN KADUNA STATE, NIGERIA.

INTRODUCTION: Kaduna State is among the three States with the highest number of confirmed COVID-19 cases. The objective of this study was to assess the knowledge, risk perception and practices of staff towards prevention and control of COVID-19 infection in schools to provide policy makers, education and health managers required information to manage the epidemic as the schools prepare to re-open. METHODS: This was a school-based survey conducted using purposive sampling of 55 schools located in nine LGAs with the highest number of reported COVID-19 cases as at October 2020. Five schools with the highest students'/pupils' enrollment in each of the LGA were selected and all staff were interviewed. Information on knowledge, risk perception and practices of prevention was collected. Descriptive statistics were generated using Stata v14 software. RESULTS: A total of 1065 staff in 55 schools completed the interview. Major sources of information are television (73%), radio (61%), and social media (57%); and 76% indicated that a virus is the causative agent of COVID-19. Overall, 70%, 19%, 7%, 9.3% and 0% respectively had adequate knowledge of cause, preventive measures, respiratory hygiene, modes of transmission and symptoms of COVID-19; however only 14% ever attended a workshop on COVID-19. Eighty-two percent and 89% respectively believed in the efficacy of face masks and handwashing as means of prevention; 39% thought that they are likely to contract COVID-19. Ninety-nine percent and 90% have ever used face mask and hand sanitizer to prevent COVID-19; 96% and 85% respectively have use these methods in previous 24hours. Between 42% and 73% of schools needed additional commodities/requirements/supplies to comply fully with COVID-19 prevention protocols. CONCLUSION: While knowledge of COVID-19 is suboptimal, perception is positive and practice is high. Thus, teachers need to be well informed and encouraged to sustain current levels of preventive measures. Government needs to provide schools with adequate preventive commodities to ensure compliance.

Magnesium Supplementation did not affect the Antiseizure Property of Ketogenic Diet but Reduced Lipid Dysmetabolism.

BACKGROUND: Ketogenic diets (KD) have been used globally in epilepsy management. Similarly, supplementation of diets with magnesium has been associated with disease prevention and improvement. However, the effect of magnesium (Mg) supplementation in conjunction with KD on epilepsy has not yet been investigated. We hypothesized that magnesium supplementation in KD would improve the effectiveness of the diet. METHODS: Forty-eight male Wistar rats were used for the study. The animals were fed on 4 diet types: I-normal rat chow (ND), II-ND with Mg supplement (ND+Mg), III-medium chain ketogenic diet (KD) and IV-KD with Mg supplement (KD+Mg). Animals in each group were divided into 3: experimental, control and observatory. The experimental drug was intraperitoneal Pentylenetetrazole (PTZ) administered at 25 mg/kg. The rats were observed for 2 hours after the drug administration and induced seizures noted. The levels of serum electrolytes and plasma lipid levels were determined using standard methods. RESULTS: The seizure latency was significantly prolonged 60.8±0.5mins in group III compared with 8.7±2.1mins in group I (p<0.05). The seizure duration was 42.5±2.5mins in group III and 142.3±4.7 in group I (p<0.05). With Mg supplementation, seizure latency was 62.6±1.5mins in group IV and 7.9±0.7mins in group I (p<0.05). The seizure duration was 45.5±4.5min in group IV and 139.3±3.9mins in group II (p< 0.05). The KD-fed rats showed a tendency to develop dyslipidemia as evidenced by elevated Total Cholesterol /HDL and LDL/HDL (2.32±0.32 and 1.19±0.08) in group III, which was reversed in the KD+Mg fed group IV (1.96±0.32 and 1.08±0.09) with p<0.05. CONCLUSION: Mg supplementation of KD did not affect its antiseizure property and does not confer antiseizure effect on ND. Mg supplement showed a tendency to reduce derangement in lipid metabolism associated with KD.

Preparation of magnetic, macro-reticulated cross-linked chitosan for tetracycline removal from aquatic systems.

A novel adsorbent, magnetic, macro-reticulated cross-linked chitosan (MRC) was synthesised for the removal of tetracycline (TC) from water using a source of biogenic waste (gastropod shells) as a pore-forming agent. The insertion of crosslinks into the chitosan frame was confirmed by FTIR analysis, while the stability of the MRC was demonstrated via a stability test performed in an acidic solution. The enhanced porosity of the MRC was confirmed by the evaluation of its porosity, a swelling test and the determination of its specific surface area. The time-concentration profile of the sorption of TC onto the MRC demonstrated that equilibrium was attained relatively quickly (120 min), and the data obtained fitted a pseudo second order (r(2)>0.99) kinetic equation better than a pseudo first order or reversible first order kinetic equation. The optimisation of process variables indicated that the sorption of TC onto the MRC was favoured at a low solution pH and that the presence of organics (simulated by the addition of humic acid) negatively impacted the magnitude of TC removal. The area of coverage of TC on the MRC (2.51 m(2)/g) was low compared to the specific surface area of the MRC (47.95 m(2)/g). The value of the calculated energy of adsorption of TC onto the MRC was 100 kJ/mol, which is far above the range of 1-16 kJ/mol stipulated for physical adsorption.

Relation between some haematological abnormalities, degree of immunosuppression and viral load in treatment-naïve HIV-infected patients.

This cross-sectional study at a teaching hospital in north-eastern Nigeria estimated the prevalence of anaemia, leukopenia and thrombocytopenia in treatment-naïve HIV-infected patients (177 males and 316 females), and the associations with virological and immunological markers. The overall prevalences of anaemia, leukopenia and thrombocytopenia were 49.5%, 5.5% and 4.5% respectively. The prevalence of anaemia was significantly higher in males than females (61.6% versus 42.7%), while the rates of leukopenia (5.1% versus 5.7%) and thrombocytopenia (5.7% versus 3.8%) were similar. Almost two-thirds of the HIV treatment-naïve studied patients, 293/493 (59.4%), had cytopenia and would require antiretroviral drugs. AIDS was diagnosed by clinical or immunological criteria in 70% of patients. The degree of cytopenia was directly related to the degree of immunosuppression and clinical AIDS status. No relationship was observed between cytopenia and viral load.

Tn7::In2-8 dispersion in multidrug resistant isolates of Acinetobacter baumannii from Chile.

Acinetobacter baumannii is considered an important pathogen in our hospital environment having a well-known capacity to acquire different mechanisms of antibiotic resistance. Previous studies in our laboratory had exposed the high dispersion of class 2 integrons in this species. In the present study, we analyzed 7 multiresistant intI2 positive A. baumannii isolates, 6 of which were found to harbour the Tn7::In2-8 element. Our results demonstrate the unusually high distribution of Tn7::In2-8 among different A. baumannii clones from Chile, suggesting a particular behavior of these elements at geographical level.

Detection of the floR gene in a diversity of florfenicol resistant Gram-negative bacilli from freshwater salmon farms in Chile.

Florfenicol is an important antibiotic in veterinary medicine that is used extensively in aquaculture, including salmon farming in Chile. We analysed a set of 119 florfenicol-resistant Gram-negative bacilli from seven freshwater Chilean salmon farms for the molecular determinants involved in the florfenicol resistance. Ninety-seven of these strains were glucose non-fermenting bacilli, mainly belonging to the Pseudomonas genus, whereas 22 strains were glucose-fermenters. The floR gene was detected in 26 strains (21.8%) that had been isolated from three of the seven salmon farms. Most of the floR-carrying strains were glucose fermenters (21 strains), and most of the floR-carrying strains were also resistant to streptomycin, chloramphenicol and oxytetracycline. The minimum inhibitory concentrations against florfenicol were assessed in the presence and absence of the efflux pump inhibitor Phe-Arg-beta-naphthylamide (MC-207,110). There was evidence that in the majority of non-fermenting bacteria (82 strains), florfenicol resistance was at least partially mediated by non-specific efflux pump systems. Given the diversity of antibiotic resistance patterns observed in this study in the floR-positive isolates, a single antibiotic has the potential to co-select for a diversity of resistances. For this reason, human health as well as animal health can potentially be impacted by the use of antibiotics in aquaculture. To assess this potential risk, future studies should focus on the ability of different antibiotics used in aquatic environments to co-select for multiple resistances, the molecular basis of this diversity of resistance, and whether the genes conferring resistance can be transferred to other bacteria, including those of human health concern.

Induction of chimerism in rhesus macaques through stem cell transplant and costimulation blockade-based immunosuppression.

A strategy for producing high-level hematopoietic chimerism after non-myeloablative conditioning has been established in the rhesus macaque. This strategy relies on hematopoietic stem cell transplantation after induction with a non-myeloablative dose of busulfan and blockade of the IL2-receptor in the setting of mTOR inhibition with sirolimus and combined CD28/CD154 costimulation blockade. Hematopoietic stem cells derived from bone marrow and leukopheresis products both were found to be successful in inducing high-level chimerism. Mean peripheral blood peak donor chimerism was 81% with a median chimerism duration of 145 days. Additional immune modulation strategies, such as pre-transplant CD8 depletion, donor-specific transfusion, recipient thymectomy or peritransplant deoxyspergualin treatment did not improve the level or durability of chimerism. Recipient immunologic assessment suggested that chimerism occurred amidst donor-specific down-regulation of alloreactive T cells, and the reappearance of vigorous T-mediated alloreactivity accompanied rejection of the transplants. Furthermore, viral reactivation constituted a significant transplant-related toxicity and may have negatively impacted the ability to achieve indefinite survival of transplanted stem cells. Nevertheless, this chimerism-induction regimen induced amongst the longest-lived stem cell chimerism reported to date for non-human primates and thus represents a platform upon which to evaluate emerging tolerance-induction strategies.

Communities' awareness, perception and participation in the Community-Based Medical Education of the University of Maiduguri.

BACKGROUND: Community-based medical education (CBME) is no longer a new innovation in medical education since the establishment of The Network: Towards Unity for Health (The Network: TUFH) 25 years ago. The CBME of the University of Maiduguri medical college is 14 years old and has never been assessed in terms of the population it serves. The study was conducted to determine the level of awareness, perception, and participation of the communities in CBME. METHODS: A cross-sectional survey was carried out in 11 village units of three Local Government Areas (LGAs) using a 14-item structured questionnaire administered to adults in randomly selected households. The questionnaire was based on guide questions used for focus group discussions held earlier with community leaders. RESULTS: Awareness of students' visits among respondents was 73.7%. Knowledge of the frequency of presence of the students in the communities was 72.2%. "To examine and treat" (33.6%) and "to ask questions" (16.6%) were the most prominent reasons given for the visits. The majority of respondents perceived the visits as beneficial (72.2%). More frequent visits were requested by 54.4% of the respondents. The communities were willing to be more accessible and felt that the LGAs should provide more logistic support to the program. DISCUSSION: This study revealed that communities were aware of students' visits and knew reasons for the visits, thought visits were beneficial, and were willing to provide more support for these visits.

Integrones y cassettes genéticos de resistencia a antimicrobianos en cepas de Shigella flexneri / Integrons and antimicrobial resistance gene cassettes in Shigella flexneri strains

BACKGROUND: The resistance of Shigella flexneri to antimicrobial agents can be associated to the presence of integrons that may contain and express antimicrobial resistance gene cassettes. AIM: To study antimicrobial resistance and the presence of integrons and antimicrobial gene cassettes in Shigella flexneri strains. MATERIAL AND METHODS: In vitro susceptibility to 27 antimicrobials was studied in twenty four Shigella flexneri strains isolated from stools. The presence of integrons class 1, 2 and 3 and antimicrobial resistance gene cassettes was investigated by polymerase chain reaction (PCR) using specific primers for each gene. RESULTS: Most strains were resistant to one of the following antimicrobials: ampicillin, sulphonamide, trimethoprim, tetracycline, streptomycin, sulfamethoxazole-trimethoprim or chloramphenicol. Twenty nine percent were simultaneously resistant to all these antimicrobials. Integrons class 1 and 2 were found in 19 strains (79 per cent). Class 3 integrons were not found. Gene cassettes dfrA1 and ant(3")I were associated to integrons class 2 in most strains (15/20, 75 per cent). Genes cat, tetB and blarTEM were detected in 18/24 (75 per cent), 7/24 (29 per cent) and 4/24 (17 per cent) of the strains, respectively and were not associated to any of the studied integrons. Genes that codify enzymes AAC(6')Ib and APH(3')VI were not detected in any strain. CONCLUSIONS: The high frequency of integrons found in the studied strains, could partly explain the increasing antimicrobial resistance of Shigella flexneri strains, isolated in Chile.

Activity of cefepime, cefotaxime, ceftazidime, and aztreonam against extended-spectrum-producing isolates of Klebsiella pneumoniae and Escherichia coli from Chilean hospitals.

Resistance of Gram-negative bacilli to third-generation cephalosporins has been increasing due to the production of extended-spectrum beta-lactamases. In this work, the activities of cefepime, cefotaxime, ceftazidime, and aztreonam, alone and in association with clavulanic acid, against isolates of Klebsiella pneumoniae and Escherichia coli are compared. These isolates produce extended-spectrum beta-lactamases as shown by the synergy tests and by the decrease in the MICs of cephalosporins in the presence of clavulanic acid. Cefepime was the most active compound against these microorganisms. In addition, the microorganisms exhibited lower frequencies of resistance to this cephalosporin.

[Presence of integrons and their relationships with the resistance to third generation cephalosporins among nosocomial isolates of Acinetobacter baumannii]. / Presencia de integrones y su relación con la resistencia a cefalosporinas de tercera generación en cepas de Acinetobacter baumannii de origen nosocomial.

BACKGROUND: Acinetobacter baumannii is an important etiological agent causing nosocomial infections. High level of resistance for different kind of antimicrobials has been observed, including beta-lactam antibiotics. This feature, chromosomal or plasmid encoded, has been associated to integrons harbouring antibiotic resistance gene cassettes. AIMS: To investigate the presence of integrons among clinical isolates resistant to third generation cephalosporins (3GC). MATERIAL AND METHODS: One hundred A. baumannii strains isolated from several Chilean hospitals were included in this study. Minimal inhibitory concentrations (MIC) of 3GC by an agar dilution method were carried out. Integrons class 1, 2 and 3 were investigated by colony blot hybridisation and confirmed by PCR. RESULTS: High level of resistance to all assayed 3GC was observed. On the other hand, integrón class 2 was the most prevalent (77% of isolates) followed by integron class 1 (52%). Forty six percent of isolates hybridised with probes for both of them. However, no positive hybridisation was detected for integron class 3. CONCLUSIONS: Nevertheless, most isolates harboured one or both class of integron; there was no direct relationship between the presence of these genetic structures and the resistance to this kind of beta-lactam antibiotics.

[Activity of imipenem and meropenem against strains of Acinetobacter baumannii isolated from various Chilean hospitals]. / Actividad de imipenem y meropenem sobre cepas de Acinetobacter baumannii aisladas en hospitales chilenos(1990-1998).

The activity of two carbapenem compounds, imipenem and meropenem, against 447 strains of Acinetobacter baumannii isolated between 1990 and 1998 in different Chilean hospitals was determined. MIC ranges, MIC(50) and MIC(90), were determined by an agar dilution method. Similar antibacterial activities were observed for both antibacterials; however, a slight increase in the MIC(50) of imipenem and meropenem, and in the MIC(90) of meropenem was found among strains isolated from 1997-1998. Although A. baumannii remains susceptible to these antibiotics, the MIC(50) and MIC(90) have increased in recent years.

Composition and antimicrobial activity of the essential oil of Peumus boldus leaves.

The composition and the antimicrobial activity of the essential oil from the leaves of Peumus boldus is investigated. Analyses of the oil obtained by hydrodistillation were carried out by GC and GC-MS using columns of two different stationary phases. Fractionation of the essential oil by column chromatography on silica gel was performed to improve identification of some constituents. More than 90% of the total oil (46 components) was identified, major constituents being monoterpenes (90.5%), among which limonene (17.0%), p-cymene (13.6%), 1.8-cineole (11.8%), and beta-phellandrene (8.4%) reached the highest percentages. Determination of the minimal bactericidal or fungicidal concentration against several microorganisms showed interesting activities towards Streptococcus pyogenes, Micrococcus sp., and Candida sp.

Presence of integrons in isolates of different biotypes of Acinetobacter baumannii from Chilean hospitals.

Class 1 and class 2 integrons were investigated by hybridisation in 100 isolates of multiresistant biotypes of Acinetobacter baumannii from Chilean hospitals. Most isolates of A. baumannii biotype 9, the prevalent biotype, harboured integrons of class 2 (Tn7-like) whereas no integrons were detected in infrequent biotypes. Integron-carrying isolates exhibited broader antibiotic resistance patterns as well as higher resistance levels to various antimicrobials.

[Adherence of Acinetobacter baumannii to rat tracheal tissue]. / Adherencia de Acinetobacter baumannii al tejido de tráquea de la rata.

BACKGROUND: Acinetobacter baumannii is an important nosocomial pathogen whose virulence factors have not been fully elucidated. AIM: To study the adherence and hemagglutinating capacity of several biotypes of Acinetobacter baumannii. MATERIAL AND METHODS: Thirty nine strains of Acinetobacter baumannii isolated from hospitalized patients were studied. The adherence of these strains to small pieces of rat tracheal tissue was studied. Additionally, their ability to hemagglutinate human erythrocytes and the effect of D-mannose and D-galactose on the adherence and hemagglutinating capacity was assessed. Transmission electron microscopy of strains was performed looking for the presence of fimbriae. RESULTS: All strains exhibited adherence to tissues. All strains had also D-mannose and D-galactose resistant hemagglutinating ability. Fimbriae were found in Acinetobacter baumannii and E coil cells. CONCLUSIONS: Adherence of Acinetobacter baumannii to rat tracheal tissue, apparently not related to the presence of fimbriae, may be a virulence mechanism of this bacterium.