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1.
Med J Malaysia ; 79(1): 74-79, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38287761

RESUMO

INTRODUCTION: Salmonella typhi could infect the intestinal tract and the bloodstream or invade body organs and secrete endotoxins. It is endemic in developing countries. It is increasingly evolving antimicrobial resistance to several commonly used antimicrobial agents. MATERIALS AND METHODS: A cross-sectional study was done at Iraqi Communicable Disease Control Center, where all confirmed cases of Salmonella typhi are reported, for a period 2019-2021. All demographic, epidemiological and clinical characteristics of patients, comorbidities, type of samples, distribution of S. typhi by age and gender, time distribution in each year and profile of bacterial resistance and sensitivity to antibiotics were gathered and analysed. RESULTS: Most samples were taken from blood. The mean age of cases during 2019, 2020 and 2021 was 18.7 ± 6.5, 17.7 ± 14.1 and 17.3 ± 12.8. Males constituted 56.7%, 58.5% and 39.8%, respectively. Some cases had comorbidities. Most cases had headache and fever. Some of them had nausea, diarrhoea, vomiting and epigastric pain. The age and sex were significantly associated with years of reporting. The most months of case reporting were June-July (2019 and 2021), Jan. -Feb. (2020). There was an obvious increase in S. typhi resistance to ceftriaxone (92.2%, 86.1%, 88.8%) and ampicillin (77.1%, 76.9%, 81.27%). There was a gradual increase in sensitivity to tetracycline (83.1%, 88.1%, 94%), cotrimoxazole (86.7%, 86.1%, 92.2%), ciprofloxacin (78.3%, 90.1%, 87.8%) and cefixime (77.7%, 72.3%, 72.7%). CONCLUSIONS: There was a sharp rise in resistance rates of the S. typhi in Iraq (during 2019-2021) to ceftriaxone and ampicillin, while there were highest sensitivity rates to imipenem, aztreonam and chloramphenicol. The following recommendations were made: (1) Improvement of general hygiene and food safety measures. (2) Emphasis on vaccination and surveillance of Salmonella infection. (3) Rational use of appropriate antibiotics through implementation of treatment guidelines. (5) Educate communities and travelers about the risks of S. typhi and its preventive measures.


Assuntos
Febre Tifoide , Masculino , Humanos , Febre Tifoide/tratamento farmacológico , Febre Tifoide/epidemiologia , Febre Tifoide/microbiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Ceftriaxona/uso terapêutico , Iraque/epidemiologia , Estudos Transversais , Prevalência , Farmacorresistência Bacteriana , Testes de Sensibilidade Microbiana , Salmonella typhi , Ampicilina/uso terapêutico
2.
Med J Malaysia ; 78(6): 717-720, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38031212

RESUMO

INTRODUCTION: Coronavirus disease 2019 (COVID-19) has high morbidity and mortality especially in preexisting risk groups. In atopic diseases the IgE and eosinophils are commonly elevated. This study aims to determine the potential association between COVID-19 and atopic diseases in Iraqi patients. MATERIALS AND METHODS: A cross-sectional study done in Baghdad on 112 patients who attended Al-Zahraa Allergic Center. Their demographic characteristics, total IgE, eosinophil counts and PCR result for COVID-19 were determined. RESULTS: The means for IgE and eosinophils were 245.7±260.1IU/ml and 444.5±117.1cells/microliter sequentially. Around 32.1% had high IgE level (i.e., atopic) and 11.6% had COVID-19. Among the atopic patients, 33.3%, 30.5% and 36.2% had atopic dermatitis, allergic rhinitis and asthma respectively. More than half (58.3%) of them were male, 55.5% aged <45 years, 36.2% were retired or had no job, 69.5% were graduated from secondary school or more and 88.8% lived in urban areas. There is no significant association in IgE level between those with and without COVID-19, which means that exposure to SARS Cov2 virus could not be a trigger or exacerbation for atopic diseases. Also, there was no association between atopic patients with COVID-19 and those without it regarding type of atopy, age, sex, occupation, education, type of living area. CONCLUSIONS: Atopy is not a risk factor for COVID-19.


Assuntos
COVID-19 , Rinite Alérgica , Humanos , Masculino , Feminino , Iraque/epidemiologia , Imunoglobulina E , Estudos Transversais , COVID-19/epidemiologia , Eosinófilos
3.
Front Plant Sci ; 14: 1143853, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37538056

RESUMO

The development of nutrient-use efficient rice lines is a priority amidst the changing climate and depleting resources viz., water, land, and labor for achieving sustainability in rice cultivation. Along with the traditional transplanted irrigated system of cultivation, the dry direct-seeded aerobic system is gaining ground nationwide. The root-related traits play a crucial role in nutrient acquisition, adaptation and need to be concentrated along with the yield-attributing traits. We phenotyped an association panel of 118 rice lines for seedling vigour index (SVI) traits at 14 and 21 days after sowing (DAS), root-related traits at panicle initiation (PI) stage in polythene bags under controlled aerobic condition, yield and yield-related traits under the irrigated condition at ICAR-IIRR, Hyderabad, Telangana; irrigated and aerobic conditions at ARS, Dhadesugur, Raichur, Karnataka. The panel was genotyped using simple sequence repeats (SSR) markers and genome-wide association studies were conducted for identifying marker-trait associations (MTAs). Significant correlations were recorded for root length, root dry weight with SVI, root volume at the PI stage, number of productive tillers per plant, spikelet fertility, the total number of grains per panicle with grain yield per plant under irrigated conditions, and the total number of grains per panicle with grain yield per plant under aerobic condition. The panel was divided into three sub-groups (K = 3) and correlated with the principal component analysis. The maximum number of MTAs were found on chromosomes 2, 3, and 12 with considerable phenotypic variability. Consistent MTAs were recorded for SVI traits at 14 and 21 DAS (RM25310, RM80, RM22961, RM1385), yield traits under irrigated conditions (RM2584, RM5179, RM410, RM20698, RM14753) across years at ICAR-IIRR, grain yield per plant (RM22961, RM1146) under the aerobic condition, grain yield per plant at irrigated ICAR-IIRR and SVI (RM5501), root traits at PI stage (RM2584, RM80, RM410, RM1146, RM18472). Functionally relevant genes near the MTAs through in-silico expression analysis in root and panicle tissues viz., HBF2 bZIP transcription factor, WD40 repeat-like domain, OsPILS6a auxin efflux carrier, WRKY108, OsSCP42, OsMADS80, nodulin-like domain-containing protein, amino acid transporter using various rice expression databases were identified. The identified MTAs and rice lines having high SVI traits (Langphou, TI-128, Mouli, TI-124, JBB-631-1), high yield under aerobic (Phouren, NPK-43, JBB-684, Ratnamudi, TI-112), irrigated conditions (KR-209, KR-262, Phouren, Keibi-Phou, TI-17), robust root traits like root length (MoirangPhou-Angouba, Wangoo-Phou, JBB-661, Dissi, NPK-45), root volume (Ratnachudi, KJ-221, Mow, Heimang-Phou, PUP-229) can be further employed in breeding programs for the targeted environments aimed at improving seedling vigour, yield-related traits under irrigated condition, aerobic condition as adaptability to water-saving technology.

4.
Front Physiol ; 11: 594845, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33329043

RESUMO

The shoot and fruit borer, Leucinodes orbonalis (Lepidoptera: Crambidae) is the major cause of low productivity in eggplant and insecticides being the mainstay of management of L. orbonalis. However, field control failures are widespread due to the evolution of insecticide resistance. Taking advantage of the whole genome sequence information, the present study investigated the level of insecticide resistance and the expression pattern of individual carboxylesterase (CE) and glutathione S-transferases (GSTs) genes in various field collected populations of L. orbonalis. Dose-mortality bioassays revealed a very high level of resistance development against fenvalerate (48.2-160-fold), phosalone (94-534.6-fold), emamectin benzoate (7.2-55-fold), thiodicarb (9.64-22.7-fold), flubendiamide (187.4-303.0-fold), and chlorantraniliprole (1.6-8.6-fold) in field populations as compared to laboratory-reared susceptible iso-female colony (Lo-S). Over-production of detoxification enzymes viz., CE and GST were evident upon enzyme assays. Mining of the draft genome of L. orbonalis yielded large number of genes potentially belonging to the CE and GST gene families with known history of insecticide resistance in other insects. Subsequent RT-qPCR studies on relative contribution of individual genes revealed over-expression of numerous GSTs and few CEs in field populations, indicating their possible involvement of metabolic enzymes in insecticide resistance. The genomic information will facilitate the development of novel resistance management strategies against this pest.

5.
Acta Psychiatr Scand ; 126(3): 219-28, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22443168

RESUMO

OBJECTIVE: Intermittent explosive disorder is common, begins early in life, and is associated with considerable impairment in the United States. The epidemiology of IED outside the United States is unknown. We examined the prevalence and correlates of IED in Iraq, where exposure to violence has been widespread during the last three decades. METHOD: Data were drawn from a national survey of the Iraq population, the Iraq Mental Health Survey (IMHS), conducted in 2006-2007. The WHO Composite International Diagnostic interview was used to assess DSM-IV disorders, including IED. The response rate was 95.2%. RESULTS: Lifetime and 12-month prevalence estimates of IED were 1.7% and 1.5%. Mean age of onset was 18.5. The mean number of lifetime attacks was 141.6 attacks, and IED-related injuries occurred 61 times per 100 lifetime cases. IED was significantly comorbid with mood and anxiety, but not substance, disorders. CONCLUSION: Although the prevalence of IED is lower in Iraq than in the United States, the disorder has an early age of onset, is highly persistent, and is associated with substantial comorbidity and functional impairment. Iraq lacks national policies or systematic programmes to reduce aggression, highlighting the importance of implementing violence prevention programmes to reduce the societal burden of violence in Iraq.


Assuntos
Ansiedade/epidemiologia , Transtornos Disruptivos, de Controle do Impulso e da Conduta/epidemiologia , Transtornos do Humor/epidemiologia , Índice de Gravidade de Doença , Violência/estatística & dados numéricos , Adolescente , Fatores Etários , Idade de Início , Agressão/psicologia , Ansiedade/psicologia , Comorbidade , Transtornos Disruptivos, de Controle do Impulso e da Conduta/psicologia , Feminino , Humanos , Iraque/epidemiologia , Masculino , Transtornos do Humor/psicologia , Prevalência , Fatores de Risco , Fatores Sexuais , Classe Social , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Violência/psicologia , Adulto Jovem
6.
East Mediterr Health J ; 16(2): 209-13, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20799576

RESUMO

To determine the prevalence of skin diseases among primary-school children in Baghdad, Iraq, a total of 2160 schoolchildren were randomly selected from 30 primary schools. Sociodemographic data were collected from each pupil and exposed parts of the body of each child were clinically examined. The overall prevalence of skin diseases was 40.9%. A significant association between the prevalence of skin diseases with education level of parents was demonstrated. The prevalence rates of transmissible and nontransmissible skin diseases were 8.8% and 33.7% respectively. The high prevalence rate may reflect prevailing low socioeconomic conditions.


Assuntos
Proteção da Criança/estatística & dados numéricos , Dermatopatias/epidemiologia , Saúde da População Urbana/estatística & dados numéricos , Adolescente , Distribuição por Idade , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Escolaridade , Feminino , Necessidades e Demandas de Serviços de Saúde , Humanos , Iraque/epidemiologia , Masculino , Pais/educação , Vigilância da População , Prevalência , Características de Residência/estatística & dados numéricos , Fatores de Risco , Distribuição por Sexo , Dermatopatias/etiologia , Dermatopatias/prevenção & controle , Fatores Socioeconômicos , Estudantes/estatística & dados numéricos
7.
East Mediterr Health J ; 16(11): 1128-32, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21218735

RESUMO

Hepatitis E virus (HEV) is a major cause of acute hepatitis in many developing countries. This study describes an outbreak of HEV infection in Al-Sadr city, Baghdad. Blood samples obtained from patients with jaundice attending 19 primary health care centres in AI-Sadr city during a 6-month period in 2005 were tested for HEV. HEV (IgM) antibodies were detected in 38.1% of 268 patients. The association of HEV infection with unacceptable residual chlorine concentrations and/or bacteriologically unsafe water samples was significant. High rates of HEV infection, low chlorine concentrations and unsafe water were reported in June. Gross isruption of sanitation and water supplies was the most likely contributing factor.


Assuntos
Surtos de Doenças/estatística & dados numéricos , Hepatite E/epidemiologia , Hepatite E/transmissão , Saúde da População Urbana/estatística & dados numéricos , Microbiologia da Água , Purificação da Água , Adolescente , Adulto , Distribuição por Idade , Área Programática de Saúde/estatística & dados numéricos , Distribuição de Qui-Quadrado , Criança , Países em Desenvolvimento , Surtos de Doenças/prevenção & controle , Estudos Epidemiológicos , Feminino , Hepatite E/prevenção & controle , Hepatite E/virologia , Humanos , Iraque/epidemiologia , Icterícia/virologia , Masculino , Prevalência , Fatores de Risco , Estações do Ano , Distribuição por Sexo , Purificação da Água/estatística & dados numéricos
8.
FEBS Lett ; 425(2): 259-62, 1998 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-9559661

RESUMO

Patch-clamp techniques were used to characterize the channel activity of mitochondrial inner membranes of two human osteosarcoma cell lines: a mitochondrial genome-deficient (rho0) line and its corresponding parental (rho+) line. Previously, two high conductance channels, mitochondrial Centum picoSiemen (mCS) and multiple conductance channels (MCC), were detected in murine mitochondria. While MCC was assigned to the protein import in yeast mitochondria, the role of mCS is unknown. This study demonstrates that mCs and MCC activities from mouse mitochondria are indistinguishable from those of human mitochondria. The channel activities and their functional expression levels are not altered in cells lacking mtDNA. Hence, rho0 cells may provide a model system for elucidating the role of mitochondrial channels in disease processes and apoptosis.


Assuntos
Canais Iônicos/fisiologia , Proteínas de Membrana/fisiologia , Mitocôndrias/fisiologia , Porinas , Animais , Linhagem Celular , Células HeLa , Humanos , Membranas Intracelulares/fisiologia , Camundongos , Células Tumorais Cultivadas , Canais de Ânion Dependentes de Voltagem
9.
Neurol India ; 46(3): 212-215, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-29508779

RESUMO

Twenty five cases of post operative cranial vault defects were repaired using tailor made silastic implants in the last three years. Twenty four patients are tolerating the implant without any problems. All of them had symptomatic, relief and achieved an excellent cosmetic skull contour. Ten patients had subgaleal serous collection postoperatively, probably due to reaction to the implanted material, which usually subsided within three weeks. Only in one patient, the implant had to be removed due to infection. In conclusion, silastic is a good implant material for cranioplasty.

10.
Biochemistry ; 31(8): 2223-9, 1992 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-1371695

RESUMO

Patch clamp analysis of membranes reconstituted with a fraction isolated from detergent-solubilized mitochondrial membranes by affinity chromatography on immobilized quinine earlier indicated the presence of two classes of ion channels, of about 40- and 140-pS conductance in medium including 150 mM KCl. Now a 57-kDa constituent of the quinine-affinity column eluate has been identified as the 40-pS channel. Protein fractions derived from the quinine-affinity column eluate by preparative isoelectric focusing with a Rotofor cell have been reconstituted into phospholipid vesicle membranes by detergent dialysis, and vesicles have been enlarged for patch clamping by dehydration and rehydration. Voltage clamp analysis has been carried out on excised patches bathed symmetrically in buffered medium containing 150 mM KCl and 100 microM CaCl2. Patches of membrane incorporating the 57-kDa protein exhibit 40-pS conductance transitions. The magnitude of conductance transitions is similar when Na+ replaces K+ in the bathing medium, indicating little selectivity of the 40-pS channel for K+ relative to Na+. Another fraction derived from the quinine-affinity column eluate is found to contain the larger channel, now estimated to have an average conductance of about 130 pS. Patches of control membrane prepared in the same way but without protein exhibit no channel activity.


Assuntos
Ativação do Canal Iônico , Canais Iônicos/química , Mitocôndrias Hepáticas/química , Animais , Fracionamento Celular , Condutividade Elétrica/fisiologia , Membranas Intracelulares/química , Potenciais da Membrana/fisiologia , Proteínas de Membrana/isolamento & purificação , Proteínas de Membrana/fisiologia , Mitocôndrias Hepáticas/fisiologia , Ratos
11.
Ann Saudi Med ; 11(6): 616-9, 1991 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17590810

RESUMO

To evaluate the significance of IgE antibodies in postoperative follow-up studies of patients with primary hydatidosis, 24 patients with detectable levels of Enchinococcus granulosus-specific IgE as determined by radioallergosorbent test (RAST) were re-examined one month and four months after surgical resection of the cyst. Serum levels of polyclonl IgE as determined by paper radiommunosorbent test (PRIST) were also determined before and after surgery. Anti-Enchinococcus IgE was undetected in 75% and 89% of patients with hepatic or pulmonary hydatidosis, respectively, four months after surgery. In addition, significant decline was observed in the serum polyclonal IgE four months after surgical removal of the cyst in both hepatic and pulmonary hydatidosis. However, surgical removal of pulmoary cyst alone showed no such effect on either polyclonal or Enchinococcus-specific IgE in hepatopulmonary hydatidosis. The results suggest that determination of specific an polyclonal IgE antibodies provide useful serological tests for prognosis and early detection of persistence and recurrence of hydatid disease postoperatively.

12.
Biochem Biophys Res Commun ; 175(1): 305-10, 1991 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-1705422

RESUMO

A protein fraction isolated from detergent-solubilized mitochondrial membranes by affinity chromatography on immobilized quinine was reconstituted into phospholipid vesicles by detergent dialysis. Vesicles were fused to a diameter of 10 microns or larger by dehydration and rehydration. Patch clamp recordings carried out in detached mode with a symmetrical solution of 150 mM KCl, 5 mM HEPES, and 0.1 mM CaCl2 revealed conductance increments of 140 pS. Transitions of 40 pS were less frequently observed. Control vesicles which lacked protein showed no channel activity. The probability for the 140 pS channel to be open increased with increasing voltage in the range from 20 to 80 mV (positive potentials relative to what was the vesicle interior prior to excision), while the single channel conductance remained essentially constant. The 140 pS channel did not open at negative voltages. The voltage dependence suggests asymmetric incorporation of the 140 pS channel into vesicle membranes during reconstitution.


Assuntos
Canais Iônicos/fisiologia , Mitocôndrias Hepáticas/fisiologia , Animais , Fracionamento Celular , Condutividade Elétrica , Potenciais da Membrana , Proteínas de Membrana/isolamento & purificação , Proteínas de Membrana/fisiologia , Mitocôndrias Hepáticas/ultraestrutura , Ratos
13.
Biochem Int ; 22(5): 843-8, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2099149

RESUMO

The pathway of unidirectional K+ flux into respiring mitochondria is sensitive to the protein reactive compounds mersalyl and dicyclohexylcarbodiimide (DCCD). When treated with either of these reagents, mitochondria retain sensitivity to other reagents which affect K+ flux into untreated mitochondria. The present studies show that the K+ influx mechanism modified by pretreatment with DCCD remains sensitive to inhibition by quinine. K+ influx stimulated by mersalyl, in the absence of exogenous Ca++, retains sensitivity to inhibition by quinine and to some extent by Mg++. The results support the conclusion that K+ uptake by mitochondria modified by mersalyl or DCCD occurs via the same proteinaceous pathway as that which mediates K+ uptake by untreated mitochondria.


Assuntos
Mitocôndrias Hepáticas/metabolismo , Potássio/metabolismo , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Dicicloexilcarbodi-Imida/farmacologia , Técnicas In Vitro , Mersalil/farmacologia , Mitocôndrias Hepáticas/efeitos dos fármacos , Consumo de Oxigênio , Quinina/farmacologia , Ratos
14.
FEBS Lett ; 273(1-2): 215-8, 1990 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-1699808

RESUMO

A protein fraction has been obtained from detergent-solubilized mitochondrial membranes by its affinity for quinine, an inhibitor of K+ transport. A peptide derived from the predominant 53 kDa protein in this fraction is found to be identical in sequence to a portion of aldehyde dehydrogenase. Antigenically unrelated bands at 97, 77, 57, and 31 kDa are also seen on polyacrylamide gels. Observations utilizing a fluorescent probe entrapped in the lumen of membrane vesicles indicate that the reconstituted protein fraction imparts permeability to the K+ analog Tl+. These and other findings suggest that the affinity purified fraction includes a cation transport catalyst.


Assuntos
Aldeído Desidrogenase/metabolismo , Proteínas de Membrana/metabolismo , Mitocôndrias Hepáticas/metabolismo , Potássio/metabolismo , Partículas Submitocôndricas/metabolismo , Tálio/metabolismo , Aldeído Desidrogenase/química , Animais , Transporte Biológico Ativo , Epitopos/análise , Corantes Fluorescentes , Cinética , Proteínas de Membrana/genética , Peso Molecular , Ratos , Valinomicina/farmacologia
15.
Biochem Biophys Res Commun ; 153(1): 224-30, 1988 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-3377787

RESUMO

A 53 kDa protein has been purified from a Triton X-100 extract of liver mitochondrial membranes, by affinity chromatography on immobilized quinine, a K+ transport inhibitor. KCl-containing lipid vesicles reconstituted with this protein lose K+ to a medium low in K+ faster than vesicles lacking protein. With bacteriorhodopsin reconstituted in vesicles containing K+, light induces faster development of a pH gradient if the 53 kDa protein is included during vesicle preparation. This effect is like that of valinomycin, which catalyzes K+ efflux, dissipating the membrane potential arising from H+ entry. Evidence that vesicles containing the 53 kDa protein are permeable to K+, but exhibit low permeability to H+, indicates that this protein acts as a K+ uniporter.


Assuntos
Mitocôndrias Hepáticas/análise , Potássio/metabolismo , Proteínas/farmacologia , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Eletroforese em Gel de Poliacrilamida , Masculino , Peso Molecular , Proteínas/isolamento & purificação , Ratos
16.
J Bioenerg Biomembr ; 20(2): 261-71, 1988 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3372496

RESUMO

Effects on Mg++ transport in rat liver mitochondria of three reagents earlier shown to affect mitochondrial K+ transport have been examined. The sulfhydryl reactive reagent phenylarsine oxide, which activates K+ flux into respiring mitochondria, also stimulates Mg++ influx. The K+ analog Ba++, when taken up into the mitochondrial matrix, inhibits influx of both K+ and Mg++. The effect on Mg++ influx is seen only if Mg++, which blocks Ba++ accumulation, is added after a preincubation with Ba++. Thus the inhibition of Mg++ influx appears to require interaction of Ba++ at the matrix side of the inner mitochondrial membrane. Added Ba++ also diminishes observed rates of Mg++ efflux but not K+ efflux. This difference may relate to a higher concentration of Ba++ remaining in the medium in the presence of Mg++ under the conditions of our experiments. Pretreatment of mitochondria with dicyclohexyl-carbodiimide (DCCD), under conditions which result in an increase in the apparent Km for K+ of the K+ influx mechanism, results in inhibition of Mg++ influx from media containing approximately 0.2 mM Mg++. The inhibitory effect of DCCD on Mg++ influx is not seen at higher external Mg++ (0.8 mM). This dependence on cation concentration is similar to the dependence on K+ concentration of the inhibitory effect of DCCD on K+ influx. Although mitochondrial Mg++ and K+ transport mechanisms exhibit similar reagent sensitivities, whether Mg++ and K+ share common transport catalysis remains to be established.


Assuntos
Magnésio/metabolismo , Mitocôndrias Hepáticas/metabolismo , Potássio/metabolismo , Animais , Arsenicais/farmacologia , Bário/metabolismo , Transporte Biológico Ativo/efeitos dos fármacos , Dicicloexilcarbodi-Imida/farmacologia , Técnicas In Vitro , Mitocôndrias Hepáticas/efeitos dos fármacos , Ratos
17.
Biochem Pharmacol ; 37(5): 957-61, 1988 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-3345205

RESUMO

Isolated rat liver mitochondria rapidly bound the 14C-labeled organic cations spermidine, a physiologically important polyamine, and methylglyoxal-bis(guanylhydrazone) (MGBG), an anticancer drug. This rapid, Mg2+-sensitive, respiration-independent binding is assumed to involve adsorption to anionic surface groups. A slower progressive uptake of the organic cations exhibited respiration dependence, indicating that it involves transport across the inner mitochondrial membrane into the matrix compartment. Addition of digitonin, to lyse the outer mitochondrial membrane, caused an increase in the mitochondrial content of the organic cations and enhanced the rate of progressive, respiration-dependent cation uptake. The data are consistent with the interpretation that the outer mitochondrial membrane limits access of the organic cations, spermidine and MGBG, to the inner mitochondrial membrane. This conclusion is supported also by published data indicating that outer membrane lysis enhances inhibitory effects of the organic cations on mitochondrial respiration. The uptake of spermidine by mitochondria was inhibited by MGBG.


Assuntos
Antimicina A/farmacologia , Digitonina/farmacologia , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitoguazona/farmacocinética , Espermidina/farmacocinética , Animais , Membranas Intracelulares/metabolismo , Magnésio/farmacologia , Mitocôndrias Hepáticas/metabolismo , Mitocôndrias Hepáticas/ultraestrutura , Permeabilidade , Potássio/farmacologia , Ratos
19.
J Bioenerg Biomembr ; 18(2): 123-34, 1986 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3722142

RESUMO

The dithiol-reactive reagent phenylarsine oxide causes a pH-dependent stimulation of unidirectional K+ flux into respiring rat liver mitochondria. This stimulation is diminished by subsequent addition of either the dithiol 2,3-dimercaptopropanol or the monothiol 2-mercaptoethanol. In contrast, uncoupling by phenylarsine oxide is reversed by 2,3-dimercaptopropanol but not by 2-mercaptoethanol. The data suggest separate sites of interaction of phenylarsine oxide with mechanisms of K+ entry and ATP synthesis. Stimulatory effects of mersalyl and phenylarsine oxide on K+ influx are not additive. Thus PheASO and mersalyl may affect K+ influx at a common site. Pretreatment of the mitochondria with DCCD, which inhibits K+ influx, fails to alter sensitivity to PheAsO or mersalyl. Thus the DCCD binding site associated with the K+ influx mechanism appears to be separate from and independent of the sulfhydryl group(s) which mediate stimulation of K+ influx by PheAsO and mersalyl. PheAsO, like mersalyl, also increases the rate of unidirectional K+ efflux from respiring mitochondria. The combined presence of PheAsO plus mersalyl causes a greater stimulation of K+ efflux than is observed with either reagent alone.


Assuntos
Arsenicais/farmacologia , Mitocôndrias Hepáticas/metabolismo , Potássio/metabolismo , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Dicicloexilcarbodi-Imida/farmacologia , Cinética , Mercaptoetanol/farmacologia , Mersalil/farmacologia , Mitocôndrias Hepáticas/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Ratos
20.
Biochem Biophys Res Commun ; 135(3): 830-6, 1986 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-3964277

RESUMO

Quinine decreases rates of unidirectional K+ flux into and out of respiring rat liver mitochondria. K+ efflux is more sensitive to quinine than K+ influx. The data are consistent with the proposal that two separate mechanisms may mediate K+ influx, only one of which is sensitive to quinine. Effects on K+ flux of the stereoisomer quinidine are similar to effects of quinine. The smaller quinuclidine causes at most a slight inhibition of K+ efflux under the same conditions. Mg++ flux exhibits a pattern of inhibition by quinine similar to that of K+ flux. Mg++ efflux is more sensitive to quinine than is Mg++ influx. These and earlier findings indicate marked similarities between liver mitochondrial transport mechanisms for K+ and Mg++.


Assuntos
Magnésio/metabolismo , Mitocôndrias Hepáticas/efeitos dos fármacos , Potássio/metabolismo , Quinina/farmacologia , Animais , Transporte Biológico/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Permeabilidade , Quinidina/farmacologia , Quinuclidinas/farmacologia , Ratos , Desacopladores
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