Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Hepatol ; 81(1): 163-183, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38527522

RESUMO

Patients with cirrhosis are prone to developing acute kidney injury (AKI), a complication associated with a markedly increased in-hospital morbidity and mortality, along with a risk of progression to chronic kidney disease. Whereas patients with cirrhosis are at increased risk of developing any phenotype of AKI, hepatorenal syndrome (HRS), a specific form of AKI (HRS-AKI) in patients with advanced cirrhosis and ascites, carries an especially high mortality risk. Early recognition of HRS-AKI is crucial since administration of splanchnic vasoconstrictors may reverse the AKI and serve as a bridge to liver transplantation, the only curative option. In 2023, a joint meeting of the International Club of Ascites (ICA) and the Acute Disease Quality Initiative (ADQI) was convened to develop new diagnostic criteria for HRS-AKI, to provide graded recommendations for the work-up, management and post-discharge follow-up of patients with cirrhosis and AKI, and to highlight priorities for further research.


Assuntos
Injúria Renal Aguda , Síndrome Hepatorrenal , Cirrose Hepática , Humanos , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/terapia , Cirrose Hepática/complicações , Síndrome Hepatorrenal/etiologia , Síndrome Hepatorrenal/terapia , Síndrome Hepatorrenal/diagnóstico , Ascite/etiologia , Ascite/terapia , Ascite/diagnóstico , Consenso
2.
Semin Dial ; 36(1): 12-17, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35840146

RESUMO

BACKGROUND: Patients with multiple myeloma and high serum levels of circulating free light chains (FLC) have increased risk of acute kidney injury (AKI) secondary to cast nephropathy and is associated with poor survival. Despite removal of FLC by medium cutoff (MCO) dialyzer, the role of MCO hemodialysis (HD) in the treatment of cast nephropathy and its clinical benefits remain unknown. METHODS: A systematic review was conducted to establish the effectiveness of MCO dialyzer and clinical outcomes, compared to other forms of dialyzers in the removal of FLC, in myeloma patients with AKI. The primary outcome was effectiveness of MCO-HD in reducing serum FLC. The secondary outcomes were HD independence, estimated glomerular filtrate rate, mortality rates, length of hospitalization, rebound of serum FLC before the next dialysis, removal of other molecules during dialysis, and adverse events. RESULTS: We identified three case series, with a total of 17 patients. There were no randomized controlled trials (RCTs) or cohort studies. These case series showed that MCO dialyzer was effective in the removal of FLC and led to a reduction in FLC concentration post-dialysis. The majority of the case series did not have comparator arm and renal and/or other clinical outcomes. CONCLUSION: MCO dialyzer appeared to be effective in the removal of FLC based on the existing limited data. However, more data, particularly large-scale RCTs, are needed to assess the use of MCO dialyzer in reducing serum FLC and its effect on clinical outcomes in patients with multiple myeloma and AKI.


Assuntos
Injúria Renal Aguda , Mieloma Múltiplo , Humanos , Diálise Renal/efeitos adversos , Mieloma Múltiplo/complicações , Mieloma Múltiplo/terapia , Cadeias Leves de Imunoglobulina
3.
J Clin Apher ; 38(1): 16-23, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36197100

RESUMO

INTRODUCTION: Double-filtration plasmapheresis (DFPP) has been utilized for immunomodulation in kidney transplantation. Anticoagulation is important to maintain circuit patency during DFPP. We aimed to compare the efficacy and safety of regional citrate anticoagulation (RCA) with systemic heparin anticoagulation during DFPP in kidney transplant recipients. METHODS: A retrospective cohort study was conducted to compare the efficacy and safety of RCA (RCA-DFPP) to systemic heparin anticoagulation (Hep-DFPP) for DFPP among kidney transplant recipients in a single tertiary center. RESULTS: A total of 112 sessions of DFPP were performed for 23 subjects, of which 62 sessions were RCA-DFPP and 50 sessions were Hep-DFPP. There were 13 sessions (11.6%) of premature circuit clotting, 10 sessions (16.1%) for RCA-DFPP and 3 sessions (6.0%) for Hep-DFPP (P = .10). All premature circuit clotting episodes occurred in subjects who underwent DFPP through a vascular catheter. Premature circuit clotting was associated with the use of a vascular catheter (odds ratio [OR] 14.2, 95% confidence interval [CI] 2.7-73.7; P < .01) and high postfilter ionized calcium (OR 12.7, 95% CI 1.4-112.5; P < .01). There was no major bleeding event. Hep-DFPP was associated with higher occurrence of hypocalcemia (OR 1.1, 95% CI 1.0-1.2; P < .01) and metabolic acidosis (OR 1.4, 95% CI 1.2-2.0; P = .04), while hypomagnesemia was more common for RCA-DFPP (OR 2.9, 95% CI 1.1-7.4; P = .03). CONCLUSION: Amongst kidney transplant patients who receive DFPP therapy, RCA-DFPP may be comparable to Hep-DFPP for the maintenance of circuit patency. Functioning vascular access is vital in avoiding premature clotting of the circuit. Close monitoring of electrolyte imbalances and coagulopathy related to DFPP is recommended.


Assuntos
Ácido Cítrico , Heparina , Humanos , Heparina/uso terapêutico , Ácido Cítrico/uso terapêutico , Anticoagulantes/uso terapêutico , Estudos Retrospectivos , Citratos , Plasmaferese
4.
Blood Purif ; 51(4): 376-382, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34198288

RESUMO

INTRODUCTION: Double-filtration plasmapheresis (DFPP) may be used for immunomodulation in kidney transplant (KTx). While DFPP reduces plasma product exposure, risk of circuit clotting merits adequate anticoagulation. Regional citrate anticoagulation (RCA) avoids the risks of systemic anticoagulation, but a protocol for RCA-DFPP is not previously widely described. METHODS: We conducted a single-center retrospective cohort study involving adult (≥21 years old) KTx recipients who underwent RCA-DFPP from 2018 to 2020 to investigate efficacy and safety for an RCA protocol during DFPP in KTx recipients. RESULTS: Fifty-one (85%) of 60 RCA-DFPP sessions in 17 patients completed without circuit clotting. Circuit clotting was associated with high post-filter ionized calcium (28 vs. 3.7%, odds ratio 10.1, 95% CI 1.1-89.4, p = 0.037). Hypo- and hypercalcemia developed in 5 (8.3%) and 8 (13.3%) sessions, respectively, but no adverse effects were noted despite severe hypocalcemia in one. There was no significant change in pre- and post-RCA-DFPP sodium, bicarbonate, albumin, and platelet levels. With regards DFPP procedure, prolongation of prothrombin time (PT) and activated partial thromboplastin time (aPTT) was observed following 38 (64.4%) and 12 (20.3%) sessions, respectively. Severely prolonged (>1.5 × upper limit normal) PT and aPTT were recorded in 2 sessions each. Expectedly, hypofibrinogenemia developed after 31 (51.7%) sessions: including 4 (6.7%) severe hypofibrinogenemia (<0.5 g/L). Two patients developed bleeding requiring blood product transfusion. The median total volume of fluids administered per session was 1.495 (1.373-1.612) L; post-RCA-DFPP significant weight gain of 0.5 (0-1.25) kg was noted. Diuretic was commenced or dose increased following 20 (33.3%) sessions for fluid balance management. DISCUSSION/CONCLUSION: Protocol-based RCA for DFPP is feasible and safe in KTx recipients. However, DFPP-related coagulopathy can develop consequent to treatment; caution should be exercised for patients with bleeding risk. Close monitoring and management of the patients' electrolytes, especially hypocalcemia and hypomagnesemia, and fluid status is recommended.


Assuntos
Ácido Cítrico , Transplante de Rim , Adulto , Anticoagulantes/efeitos adversos , Citratos , Ácido Cítrico/efeitos adversos , Humanos , Plasmaferese/métodos , Estudos Retrospectivos , Adulto Jovem
5.
J Clin Apher ; 36(1): 211-218, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33220117

RESUMO

Therapeutic plasma exchange (TPE) and continuous kidney replacement therapy (CKRT) are extracorporeal therapeutic procedures often implemented in management of patients. Critically ill patients may be afflicted with disease processes that require both TPE and CKRT. Performing TPE discontinuous with CKRT is technically easier, however, it disrupts CKRT and may compromise with CKRT efficiency or hemofilter life. Concurrent TPE with CKRT offers several advantages including simultaneous control of disease process and correction of electrolyte, fluid, and acid-base disturbances that may accompany TPE. Additionally, TPE may be performed by either centrifugation method or membrane plasma separation method. The technical specifications of these methods may influence the methodology of concurrent connections. This report describes and reviews two different approaches to circuit arrangements when establishing concurrent TPE and CKRT.


Assuntos
Centrifugação/métodos , Troca Plasmática/métodos , Terapia de Substituição Renal , Adulto , Feminino , Humanos
6.
Postgrad Med J ; 97(1154): 777-781, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32913034

RESUMO

BACKGROUND: WHO has recommended personal hygiene (respiratory hygiene, using face masks, washing hands with warm water and soap, use of alcohol-based hand sanitizers, avoid touching mouth, eyes & nose, cleanliness), social distancing and careful handling of purchased products as an effective preventive measure for COVID-19 disease. The growing pandemic of COVID-19 disease requires social distancing and personal hygiene measures to protect public health. But this message is not clear and well understood among people. The aim of this study is to determine the awareness, knowledge and attitude about COVID-19 and relate the behaviour of Indian society, especially when the country is restarting all its economic activities, after the complete lockdown. METHOD: The present paper is based on an extensive survey among 21 406 adult participants of various sections of Indian society with different age groups between 18 and 80 years to introspect the level of public awareness with respect to cause, spread, prevention and treatment of disease caused by spread of COVID-19 viral outbreak, which will be automatically reflected in the societal behavioural response of rigorous precautionary measures. CONCLUSIONS: There is a need to extend the knowledge base among individuals to enhance their active participation in the prevention mechanisms with respect to the spread of the pandemic. There is a need to elaborate the Indian socio-cultural aspects, so that society starts appreciating and voluntarily following social distancing. This should improve the adaptability of people with livelihood resilience to let them protect themselves not only from the present pandemic but also from all other unforeseen infections, and to provide care to patients.


Assuntos
COVID-19/prevenção & controle , Controle de Doenças Transmissíveis , Comportamentos Relacionados com a Saúde , Conhecimentos, Atitudes e Prática em Saúde , Adolescente , Adulto , Idoso , COVID-19/epidemiologia , COVID-19/transmissão , Estudos Transversais , Feminino , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Fatores Socioeconômicos , Adulto Jovem
7.
Am J Kidney Dis ; 76(3): 392-400, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32505811

RESUMO

With the exponential surge in patients with coronavirus disease 2019 (COVID-19) worldwide, the resources needed to provide continuous kidney replacement therapy (CKRT) for patients with acute kidney injury or kidney failure may be threatened. This article summarizes subsisting strategies that can be implemented immediately. Pre-emptive weekly multicenter projections of CKRT demand based on evolving COVID-19 epidemiology and routine workload should be made. Corresponding consumables should be quantified and acquired, with diversification of sources from multiple vendors. Supply procurement should be stepped up accordingly so that a several-week stock is amassed, with administrative oversight to prevent disproportionate hoarding by institutions. Consumption of CKRT resources can be made more efficient by optimizing circuit anticoagulation to preserve filters, extending use of each vascular access, lowering blood flows to reduce citrate consumption, moderating the CKRT intensity to conserve fluids, or running accelerated KRT at higher clearance to treat more patients per machine. If logistically feasible, earlier transition to intermittent hemodialysis with online-generated dialysate, or urgent peritoneal dialysis in selected patients, may help reduce CKRT dependency. These measures, coupled to multicenter collaboration and a corresponding increase in trained medical and nursing staffing levels, may avoid downstream rationing of care and save lives during the peak of the pandemic.


Assuntos
Betacoronavirus , Terapia de Substituição Renal Contínua/tendências , Infecções por Coronavirus/terapia , Necessidades e Demandas de Serviços de Saúde/tendências , Pandemias , Pneumonia Viral/terapia , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/terapia , Anticoagulantes/administração & dosagem , Anticoagulantes/provisão & distribuição , COVID-19 , Terapia de Substituição Renal Contínua/instrumentação , Infecções por Coronavirus/epidemiologia , Soluções para Diálise/administração & dosagem , Soluções para Diálise/provisão & distribuição , Humanos , Pneumonia Viral/epidemiologia , Insuficiência Renal/epidemiologia , Insuficiência Renal/terapia , SARS-CoV-2
8.
Ann Plast Surg ; 84(4): 375-378, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31977529

RESUMO

BACKGROUND: Burned patients with acute kidney injury (AKI) requiring renal replacement therapy (RRT) have exceedingly high mortality rates of 73% to 100%. Since January 2011, we have been adopting an early RRT approach in managing burned patients with AKI. Our hypothesis was that early initiation of RRT leads to improved outcome and survival among burned patients with AKI. METHODOLOGY: We conducted a retrospective analysis of Burns Database in Singapore General Hospital from January 2011 to February 2016. Indications for dialysis included serum creatinine of greater than 1.5 times baseline or urine output of less than 0.5 mL/kg per hour for at least 6 consecutive hours. Patients with similar condition from January 2006 to December 2010 were recruited for comparison. RESULT: A total of 27 patients with burns and AKI were recruited from January 2011 to February 2016. The mean age was 45.4 years and 88.9% were male. The mean total burn surface area (TBSA) was 54.8%. The total volume of fluid resuscitation was 2.7 mL/kg per TBSA. The time from onset of burn to RRT was 6.4 days. Most patients presented with stage 1 AKI (51.9%), whereas 22.2% and 25.9% had stage 2 and stage 3 AKI, respectively. Most patients (74.1%) received CRRT and 18.5% received SLED. The mortality rate was 37.0% with majority of death (70%) due to sepsis/multiorgan failure. Only 1 patient required long-term RRT after discharge, and there was no occurrence of abdominal compartment syndrome. The mean age of 15 patients from 2006 to 2010 was 47.8 years. The mean TBSA was 49.5%. Only 26.7% of patients were started on RRT. The mortality rate was 66.7%, which was higher than that of subjects from 2011 to 2016 (37.0%) (P = 0.039). CONCLUSIONS: Optimal timing of RRT for burned patients with AKI has not been established and data on early RRT approach are scarce. The findings of our study suggested that early RRT was associated with lower mortality rates among burned victims with AKI.


Assuntos
Injúria Renal Aguda , Queimaduras , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/terapia , Queimaduras/complicações , Queimaduras/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Terapia de Substituição Renal , Estudos Retrospectivos , Singapura/epidemiologia
9.
Physiol Plant ; 166(2): 570-584, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30035317

RESUMO

In Anabaena sp. PCC 7120, iron is an essential trace element and its availability determines proper functioning of several kinds of metabolisms. Iron deficiency leads to several unavoidable consequences including membrane damage. In the present study, we dealt with the impact of iron deficiency on NtcA (global nitrogen regulator)-dependent regulation of two important processes, i.e. fatty acid desaturation and heterocyte envelop formation in cyanobacterium Anabaena sp. PCC 7120. In Anabaena sp. PCC 7120, NtcA regulates fatty acid desaturation by regulating enzyme fatty acid desaturases. The NtcA-based regulation of fatty acid desaturation may be direct or indirect. Furthermore, the expression of genes involved in the heterocyte envelope polysaccharide (HEP) layer formation (hepABCK) and heterocyte-specific glycolipids (HGLs) synthesis (devH, hglEA , prpJ and devB) were also under the control of NtcA and reduced under iron deficiency background. The enhanced expression of furA and early downregulation of ntcA under iron deficiency is responsible for reduction in fatty acid desaturation as well as decrease in the expression of genes involved in HEP layer formation and HGL synthesis. Overall results confirmed that iron deficiency influences the NtcA-based regulation of fatty acid desaturation and heterocyte envelop formation in Anabaena sp. PCC 7120.


Assuntos
Anabaena/metabolismo , Ácidos Graxos/metabolismo , Deficiências de Ferro , Ferro/metabolismo , Anabaena/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regiões Promotoras Genéticas/genética
10.
Blood Purif ; 47 Suppl 3: 1-6, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30982048

RESUMO

The use of the oXiris® haemofilter during continuous veno-venous haemodiafiltration (CVVHDF) for acute kidney injury (AKI) and severe sepsis is not completely understood. Although this filter has in vitro adsorptive properties for blood-borne cytokines and other humoural mediators of sepsis, its clinical usefulness is uncertain. Given its inherent adsorptive limitation for septic mediators, we developed a CVVHDF protocol in which the oXiris haemofilter was electively changed every 12 h even though there was no clotting or adverse circuit pressures. Augmented filter membrane adsorption was conducted for 3 consecutive days. We treated a critically ill patient with severe sepsis secondary to a gram-negative bacterial infection and sepsis-associated acute kidney injury (SA- AKI) in this way. The patient required high-dose vasopressor support, required mechanical ventilation, had received 12 h of CVVHDF with conventional M100 haemofilter, was on broad spectrum antibiotics and other conventional intensive care unit (ICU) care, prior to institution of the frequent oXiris haemofilter change protocol. Following the start of elective 12 hourly oXiris filter change, the patient showed reduction in the need for vasopressor and by Day 4 of this SA- AKI frequent filter change protocol, vasopressor requirement ceased, he was extubated. He survived ICU and but not hospital stay. To this end, more clinical studies are needed.


Assuntos
Injúria Renal Aguda/terapia , Infecções por Bactérias Gram-Negativas/terapia , Hemodiafiltração/instrumentação , Sepse/terapia , Vasoconstritores/administração & dosagem , Hemodiafiltração/métodos , Humanos , Masculino , Pessoa de Meia-Idade
11.
BMC Nephrol ; 20(1): 282, 2019 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-31349813

RESUMO

BACKGROUND: Acute kidney injury (AKI) is a major global health problem. We aim to evaluate the epidemiology, risk factors and outcomes of AKI episodes in our single centre. METHODOLOGY: We prospectively identified 422 AKI and acute on chronic kidney disease episodes in 404 patients meeting KDIGO definitions using electronic medical records and clinical data from 15th July to 22nd October 2016, excluding patients with baseline estimated GFR (eGFR) of < 15 mL/min. Patients were followed up till 6 months after AKI diagnosis. RESULTS: The mean age was 65.8 ± 14.1. Majority of patients were male (58.2%) of Chinese ethnicity (68.8%). One hundred and thirty-two patients (32.6%) were diagnosed in acute care units. Seventy-five percent of patients developed AKI during admission in a non-Renal specialty. Mean baseline eGFR was 50.2 ± 27.7 mL/min. Mean creatinine at AKI diagnosis was 297 ± 161 µmol/L. Renal consultations were initiated at KDIGO Stages 1, 2 and 3 in 58.9, 24.5 and 16.6% of patients, respectively. Three hundred and ten (76.7%) patients had a single etiology of AKI with the 3 most common etiologies of AKI being pre-renal (27.7%), sepsis-associated (25.5%) and ischemic acute tubular necrosis (15.3%). One hundred and nine (27%) patients received acute renal replacement therapy. In-hospital mortality was 20.3%. Six-month mortality post-AKI event was 9.4%. On survival analysis, patients with KDIGO Stage 3 AKI had significantly shorter survival than other stages. CONCLUSION: AKI is associated with significant in-hospital to 6-month mortality. This signifies the pressing need for AKI prevention, early detection and intervention in mitigating reversible risk factors in order to optimize clinical outcomes.


Assuntos
Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/diagnóstico , Idoso , Feminino , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Análise de Sobrevida , Centros de Atenção Terciária
12.
BMC Infect Dis ; 18(1): 118, 2018 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-29514602

RESUMO

BACKGROUND: End stage renal disease (ESRD)/ end stage renal failure (ESRF) is on the rise globally and especially in Singapore. Varicella or chickenpox is not uncommon among adults especially ESRD/ESRF patients. It has been reported to cause complications and even death among immunocompetent adults. METHODS: A retrospective data collection on patients with varicella infection and ESRD in Singapore General Hospital (SGH) from the year 2005 to 2016 was performed. Continuous data and categorical data were summarized as median (range) and count (%) respectively. The association of health care utilization (total length of hospital stay, readmission related to varicella, intensive care unit admission) and mortality with complication due to varicella were tested using chi-square and Mann-Whitney test for categorical and continuous outcomes respectively. RESULTS: Sixty-six patients with ESRD developed varicella during the study period (2005-2016). The case incidence rates for varicella among ESRD ranges from 97 to 267 per 100,000 populations with ESRD yearly. There were 9 deaths (13.6%). Mortality was higher among the ESRD patients with one or more varicella complications compared to patients without complications ((25% vs 7.1%, 95% CI for difference: - 1.1%, 36.9%, p = .063). Likewise, utilisation of intensive or high dependency units were higher among patients with complications compared to those without (20.8% vs 2.4%, 95% CI for difference: 1.6%, 35.3%, p = .012). Length of stay was twice as long in the group with complications compared to patients without (median (IQR) days: 14 (8, 21) vs 7 (5, 14), p = .065), although it did not reach statistical significance. CONCLUSIONS: Varicella is associated with high morbidity and significant mortality rate in ESRD patients. Varicella vaccination is recommended for seronegative ESRD patients.


Assuntos
Varicela/diagnóstico , Falência Renal Crônica/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/sangue , Varicela/complicações , Varicela/epidemiologia , Varicela/mortalidade , Feminino , Herpesvirus Humano 3/imunologia , Hospitais Gerais , Humanos , Unidades de Terapia Intensiva , Falência Renal Crônica/complicações , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Singapura/epidemiologia , Taxa de Sobrevida , Adulto Jovem
13.
J Basic Microbiol ; 58(8): 679-685, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29921020

RESUMO

Spore (akinete) formation in the heterocystous and branched filamentous cyanobacterium Fischerella muscicola involves a significant increase in cell size and formation of several endospores in each of the cells. In present study, the physico-chemical factors (pH, light sources, nutrient deficiency, nitrogen sources, carbon sources, and growth hormones) affecting the germination of spores of F. muscicola were examined. Increase in spore germination frequency was detected above pH 8 with maximum germination (46.04%) recorded at pH 9, whereas a significant decrease in germination was observed at pH 6 when compared to control (pH 7.6). Spore germination was not observed at pH 5. Among light sources germination frequency followed the following order, that is, red light (39.9%) > white light (33.8%) > yellow light (3.4%) > green light (1.3%) whereas germination did not take place in dark and blue light. Ammonium chloride (NH4 Cl) supported maximum (99.5%) germination frequency followed by calcium nitrate (Ca(NO3 )2 ), potassium nitrate (KNO3 ), and minimum germination was observed in urea. Nutrient (phosphorus, calcium, and magnesium) deficiency significantly enhanced the germination frequency with maximum increase in magnesium (Mg) deficient condition. Further, supplementation of carbon sources (glucose, fructose, and sodium acetate) and growth hormones (IAA and GA) also enhanced the germination frequency in this cyanobacterium. Therefore, it may be concluded that, those factors supporting higher germination frequency could be considered for successful production and use of this cyanobacterium in biofertilizer and other algal production technologies.


Assuntos
Cianobactérias/fisiologia , Esporos Bacterianos/fisiologia , Carbono/metabolismo , Meios de Cultura , Cianobactérias/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Luz , Nitrogênio/metabolismo , Reguladores de Crescimento de Plantas
14.
J Basic Microbiol ; 58(2): 162-171, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29149514

RESUMO

Cyanobacteria are known to exhibit their efficiency in producing high concentrations of compounds of commercial value. Arthrospira is one such cyanobacterium which is considered as important source of protein (65%) and other nutrients. In present study, chemical mutagenesis using N-methyl-N-Nitro-nitrosoguanidine (NTG), a proven potent mutagen for cyanobacteria was used to bring stable and desirable alteration in Arthrospira platensis ARM 730. Three morphological mutants (G-1, G-2, and SF) were selected and characterized. The G-1 and G-2 were helical, more bluish in pigmentation than the wild type strain where G-1 also showed enlarged cell size. The SF mutant was an altered straight-filament having maximum biomass. Among three mutants, higher protein and phycocyanin contents were observed in G-1 and G-2 mutants whereas chlorophyll was less in these mutants as compared to wild type strain indicating change in the pigment ratio. Carotenoid content was higher in SF mutant as compared to wild type and other mutants. Variation in total sugar content was not observed in comparison to wild type strain. The analysis of amino acid spectrum of all the mutants and wild type showed significant increase in proline content. Overall, it is revealed from the results that G-1 and G-2 mutants showed higher biomass, phycocyanin, and protein contents in comparison to wild type which indicated their great potential to be used in food and pharmaceutical industries.


Assuntos
Proteínas de Bactérias/metabolismo , Mutação , Ficocianina/metabolismo , Spirulina/isolamento & purificação , Spirulina/metabolismo , Metilnitronitrosoguanidina/metabolismo , Mutagênese , Mutagênicos/metabolismo , Spirulina/citologia , Spirulina/crescimento & desenvolvimento
15.
World J Microbiol Biotechnol ; 33(8): 158, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28730560

RESUMO

Iron deficiency ends up into several unavoidable consequences including damaging oxidative stress in cyanobacteria. NtcA is a global nitrogen regulator controls wide range of metabolisms in addition to regulation of nitrogen metabolism. In present communication, NtcA based regulation of iron homeostasis, ROS production and cellular phenotype under iron deficiency in Anabaena 7120 has been investigated. NtcA regulates the concentration dependent iron uptake by controlling the expression of furA gene. NtcA also regulated pigment synthesis and phenotypic alterations in Anabaena 7120. A significant increase in ROS production and corresponding reduction in the activities of antioxidative enzymes (SOD, CAT, APX and GR) in CSE2 mutant strain in contrast to wild type Anabaena 7120 also suggested the possible involvement of NtcA in protection against oxidative stress in iron deficiency. NtcA has no impact on the expression of furB and furC in spite of presence of consensus NtcA binding site (NBS) and -10 boxes in their promoter. NtcA also regulates the thylakoid arrangement as well as related photosynthetic and respiration rates under iron deficiency in Anabaena 7120. Overall results suggested that NtcA regulates iron acquisition and in turn protect Anabaena cells from the damaging effects of oxidative stress induced under iron deficiency.


Assuntos
Anabaena/genética , Anabaena/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Homeostase , Ferro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Anabaena/enzimologia , Ascorbato Peroxidases/análise , Sítios de Ligação , Catalase/análise , Eletrólitos , Genes Bacterianos/genética , Glutationa Redutase/análise , Peroxidação de Lipídeos , Mutação , Estresse Oxidativo , Fotossíntese/fisiologia , Pigmentos Biológicos/análise , Regiões Promotoras Genéticas , Superóxido Dismutase/análise
16.
J Basic Microbiol ; 56(8): 907-21, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27037833

RESUMO

To investigate the physiology and taxonomic composition of the key players of nitrification and denitrification processes in paddy fields, culture dependent and independent studies have been carried out. A total of 28 bacterial strains have been screened in which six were capable of reducing nitrate and nitrite as well as having significant ammonium removal potential. 16S rRNA-PCR-DGGE-based molecular typing of enriched batch culture was done with time duration to explore and identify dominant and stable soil denitrifiers. Notably, three isolates namely PDN3, PDN19, PDN14 were found to be efficiently involved in the removal of 70.32, 71.46, and 81.50% of NH4 (+) and showed closest similarity (>98%) with Bacillus cereus, Bacillus subtilis, and Pseudomonas aeruginosa strains, respectively. The bacterial strain PDN14 showed maximum growth with highest ammonium removal rate (2.78 gN/(m(3) ·h) has also been characterized based on nosZ gene which showed similarity to uncultured γ- Proteobacteria, P. aeruginosa sp. B3. Median joining (MJ) network and rRNA secondary structure have been analyzed for their detailed taxonomic diversity and derived haplotype-based co-occurrence. Results demonstrated that such strains can serve as good candidate for in situ nitrogen transformation in paddy soils and improvingly characterized by physiological and detailed phylogenetic approaches.


Assuntos
Compostos de Amônio/metabolismo , Bactérias/metabolismo , Desnitrificação/fisiologia , Nitratos/metabolismo , Nitrificação/fisiologia , Nitritos/metabolismo , Bactérias/isolamento & purificação , Fenômenos Fisiológicos Bacterianos , Biodegradação Ambiental , Processos Heterotróficos , Oryza , Filogenia , RNA Ribossômico 16S/genética , Microbiologia do Solo , Águas Residuárias/química
17.
Nephrology (Carlton) ; 20(3): 148-54, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25395245

RESUMO

AIM: Optimal timing for acute renal replacement therapy (ARRT) initiation in critically ill patients with acute kidney injury (AKI) is unclear. We aimed to evaluate outcomes in patients who initiated ARRT for traditional indications versus those who met Acute Kidney Injury Network (AKIN) criteria without traditional indications. METHODS: This was a single-centre prospective cohort study of medical and surgical intensive care patients with AKI. Traditional indications for ARRT initiation included: serum potassium ≥6.0 mmol/L, serum urea ≥30 mmol/L, arterial pH < 7.25, serum bicarbonate <10 mmol/L, acute pulmonary oedema, acute uraemic encephalopathy or pericarditis. In absence of these indications, ARRT was commenced if patients had (i) AKIN Stage 3 or (ii) AKIN Stage 1 or 2 with 'compelling' conditions. Primary outcomes were intensive care unit (ICU) and in-hospital mortality. RESULTS: ARRT was initiated in 140 patients: traditional indications in 56 (40%); AKIN Stage 3 without traditional indications in 38 (27%); and AKIN Stage 1 or 2 with 'compelling' conditions in 46 (33%) patients. Traditional indications at ARRT initiation was associated with increased in-hospital mortality (adjusted odds ratio (95% confidence interval), 6.48 (1.54, 27.29)). In absence of traditional indications, earlier ARRT initiation, as defined by those with AKIN Stage 1 or 2, did not decrease ICU deaths (30.0% vs 18.8%, P = 0.30) or in-hospital mortality (50.0% vs 34.2%, P = 0.15) compared with those who were started on ARRT for AKIN Stage 3. CONCLUSIONS: Presence of traditional indications at ARRT initiation was associated with greater mortality. Initiating dialysis at earlier AKIN stage did not improve survival in patients without traditional indications.


Assuntos
Injúria Renal Aguda/terapia , Diálise Renal , Tempo para o Tratamento , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/mortalidade , Idoso , Estado Terminal , Feminino , Mortalidade Hospitalar , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Valor Preditivo dos Testes , Estudos Prospectivos , Diálise Renal/efeitos adversos , Diálise Renal/mortalidade , Fatores de Risco , Índice de Gravidade de Doença , Singapura , Fatores de Tempo , Resultado do Tratamento
18.
J Basic Microbiol ; 55(6): 729-40, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25572501

RESUMO

The cyanobacterium Anabaena sp. PCC 7120 was grown in presence and absence of iron to decipher the role of manganese in protection against the oxidative stress under iron starvation and growth, manganese uptake kinetics, antioxidative enzymes, lipid peroxidation, electrolyte leakage, thiol content, total peroxide, proline and NADH content was investigated. Manganese supported the growth of cyanobacterium Anabaena 7120 under iron deprived conditions where maximum uptake rate of manganese was observed with lower K(m) and higher V(max) values. Antioxidative enzymes were also found to be elevated in iron-starved conditions. Estimation of lipid peroxidation and electrolyte leakage depicted the role of manganese in stabilizing the integrity of the membrane which was considered as the prime target of oxygen free radicals in oxidative stress. The levels of total peroxide, thiol, proline and NADH content, which are the representative of oxidative stress response in Anabaena 7120, were also showed increasing trends in iron starvation. Hence, the results discerned, clearly suggested the role of manganese in protection against the oxidative stress in cyanobacterium Anabaena 7120 under iron starvation either due to its antioxidative properties or involvement as cofactor in a number of antioxidative enzymes.


Assuntos
Anabaena/fisiologia , Ferro/metabolismo , Manganês/fisiologia , Estresse Oxidativo , Anabaena/crescimento & desenvolvimento , Eletrólitos/metabolismo , Peroxidação de Lipídeos , Peróxidos/metabolismo , Compostos de Sulfidrila/metabolismo
19.
Physiol Mol Biol Plants ; 20(3): 331-42, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25049460

RESUMO

Highly iterated palindromes (HIP) have been used as high resolution molecular markers for assessing the genetic variability and phylogenetic relatedness of heterocystous cyanobacteria (subsections IV and V) representing 12 genera of heterocystous cyanobacteria, collected from different geographical areas of India. DNA fingerprints generated using four HIP markers viz. HIP-AT, HIP-CA, HIP-GC, and HIP-TG showed 100 % polymorphism in all the heterocystous cyanobacteria studied and each marker produced unique and strain-specific banding pattern. Furthermore, phylogenetic affinities based on the dendrogram constructed using HIP DNA profiles of heterocystous cyanobacteria suggest the monophyletic origin of this entire heterocystous clade along with a clear illustration of the polyphyletic origin of the branched Stigonematalean order (Subsection V). In addition, phylogenetic affinities were validated by principal component analysis of the HIP fingerprints. The overall data obtained by both the phylogeny and principal component assessments proved that the entire heterocystous clade was intermixed, and there are immediate needs for classificatory reforms that satisfy morphological plasticity and environmental concerns.

20.
Artigo em Inglês | MEDLINE | ID: mdl-37680163

RESUMO

Diabetic nephropathy (DN) is the foremost ailment resulting in end-stage renal damage. Chronic hyperglycaemia and hyperlipidaemia are the foremost reason for disease progression. The disease is characterized by the severity of albuminuria and cardiovascular disorders. Approximately 20 to 40% of the global prevalence of DN is mostly reported to occur in individuals with diabetes, and nearly 28% of DN occurs in individuals with other renal disorders. The pathological mechanism is very complex, involving innumerable targets and leading to multiple pharmacological effects. Thus, the scientific community is forced to work in search of safe and potent therapeutics that can tackle the complex pathology of DN effectively. The secondary plant metabolites categorized as terpenoids gained attention as potential therapeutics contrary to others for the management of diabetic nephropathy and other associated syndromes by their strong antioxidant activity and inhibition of advanced glycation and its associated products. This review focused on herbal therapeutics for the management of diabetic nephropathy. Moreover, different types of terpenoids, their biological sources, and proposed mechanisms of action are explored for the development of a novel pharmacophore for diabetic nephropathy.


Assuntos
Diabetes Mellitus , Nefropatias Diabéticas , Humanos , Nefropatias Diabéticas/metabolismo , Terpenos/uso terapêutico , Rim/metabolismo , Prevalência , Progressão da Doença
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA