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1.
Transpl Infect Dis ; 14(4): 434-9, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22188555

RESUMEN

Penicillium marneffei is a thermally dimorphic fungus that causes severe human immunodeficiency virus-related opportunistic infection in endemic areas of Southeast Asia and has rarely been reported in solid organ transplant (SOT) recipients. We report here the case of an Australian renal transplant patient who presented with disseminated P. marneffei infection shortly after a 10-day holiday to Vietnam, and review all previously published cases of penicilliosis associated with renal transplantation. This is the first reported case, to our knowledge, of P. marneffei infection in an SOT recipient acquired during travel to an endemic country, and highlights the importance of an accurate travel history when opportunistic infection is suspected, as well as giving appropriate health advice to transplant patients who travel.


Asunto(s)
Trasplante de Riñón/efectos adversos , Micosis/diagnóstico , Penicillium/aislamiento & purificación , Viaje , Anciano , Anfotericina B/uso terapéutico , Antifúngicos/uso terapéutico , Australia , Humanos , Huésped Inmunocomprometido , Itraconazol/uso terapéutico , Masculino , Micosis/tratamiento farmacológico , Micosis/microbiología , Penicillium/clasificación , Resultado del Tratamiento , Vietnam
2.
AIDS ; 11(10): 1249-54, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9256943

RESUMEN

OBJECTIVE: The potential role of antiretroviral treatment on the infectiousness of HIV-1-infected men was examined by studying the effect of antiviral treatment on the shedding of HIV-1 in semen. METHODS: Forty-four patients enrolled in various treatment protocols were asked to donate a semen sample before they began a new antiviral treatment and at a follow-up visit after 6 to 15 weeks of treatment. Since most patients were on blinded protocols, patients were stratified by response of blood viral load. The effect of each patient's treatment was classified as good (n = 24), fair (n = 8) and marginal (n = 13) by measurement of the HIV RNA reduction in blood plasma (> 1.0 log10; 0.5-1.0 log10 and < 0.5 log10 HIV RNA copies/ml reduction, respectively). The effect of treatment on shedding of HIV-1 in semen was documented by the reduction of HIV RNA concentration in seminal plasma and by quantitative HIV-1 seminal cell culture. RESULTS: Overall, antiviral treatment resulted in a significant fall in the viral load in semen (RNA and culture) that paralleled the reduction of viral load in blood. More pronounced reductions of HIV RNA in semen were observed as the effectiveness of treatment on blood HIV RNA levels increased (median drop from baseline 0, 0.3 log10 and 0.8 log10 RNA copies/ml in patients with marginal, fair and good treatment effect, respectively). Thirteen patients lost detectable HIV RNA in blood on treatment and all of these had undetectable levels of HIV-1 in semen by culture and RNA analysis at follow-up. In 19 of the 31 patients (62%) who still had HIV RNA in their blood during treatment, semen HIV levels were below detection in semen at follow-up. CONCLUSIONS: Treatment-induced changes of HIV RNA concentration in blood are generally associated with a corresponding change in seminal HIV RNA: If confirmed in larger studies, potent antiretroviral therapy might reduce the spread of HIV-1.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , VIH-1/aislamiento & purificación , Semen/virología , Infecciones por VIH/sangre , Infecciones por VIH/transmisión , Humanos , Masculino , ARN Viral/sangre , Estadísticas no Paramétricas , Cultivo de Virus
3.
AIDS ; 13(4): 487-94, 1999 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-10197377

RESUMEN

OBJECTIVES: This study was undertaken to determine the relative effect of malaria infection on HIV concentration in blood plasma, and prospectively to monitor viral concentrations after antimalarial therapy. DESIGN: A prospective, double cohort study was designed to compare the blood HIV-1 RNA concentrations of HIV-positive individuals with and without acute malaria illness. Subjects were followed for 4 weeks after successful malaria therapy, or for 4 weeks from enrollment (controls). METHODS: Malawian adults with symptomatic Plasmodium falciparum parasitemia (malaria group) and asymptomatic, aparasitemic blood donors (control group) were tested for HIV-1 antibodies to identify appropriate study groups. The malaria group received antimalarial chemotherapy only and were followed with sequential blood films. In both groups, blood plasma HIV-1 RNA viral concentrations were determined at enrollment and again at 1, 2 and 4 weeks. RESULTS: Forty-seven malaria patients and 42 blood donors were enrolled. At enrollment blood plasma HIV-1 RNA concentrations were approximately sevenfold higher in patients with malaria than in blood donors (medians 15.1 x 10(4) and 2.24 x 10(4) copies/ml, respectively, P = 0.0001). No significant changes in median HIV-1 concentrations occurred in the 21 blood donors followed to week 4 (P = 0.68). In the 27 subjects successfully treated for malaria who were followed to week 4, a reduction in plasma HIV-1 RNA was observed from a median of 19.1 x 10(4) RNA copies/ml at enrollment, to 12.0 x 10(4) copies/ml at week 4, (P = 0.02). Plasma HIV-1 concentrations remained higher in malaria patients than controls (median 12.0 x 10(4) compared with 4.17 x 10(4) copies/ml, P = 0.086). CONCLUSIONS: HIV-1 blood viral burden is higher in patients with P. falciparum malaria than in controls and this viral burden can, in some patients, be partly reduced with antimalarial therapy.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/virología , VIH-1 , Malaria Falciparum/virología , Carga Viral , Infecciones Oportunistas Relacionadas con el SIDA/tratamiento farmacológico , Adulto , Animales , Femenino , VIH-1/genética , Humanos , Malaria Falciparum/tratamiento farmacológico , Masculino , Estudios Prospectivos , ARN Viral/sangre
4.
J Clin Endocrinol Metab ; 80(9): 2761-7, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7673421

RESUMEN

Disturbances in calcium metabolism in acute renal failure (ARF) remain incompletely understood. Most data are from patients with rhabdomyolysis. As renal impairment commonly accompanies severe malaria in the absence of rhabdomyolysis, falciparum malaria provides an alternative model of mineral homoeostasis in ARF. We studied 25 Vietnamese subjects, aged 18-63 yr, with severe malaria and 10 controls. Fourteen patients had a serum creatinine level of 250 mumol/L or less during treatment (group 1), five developed ARF but were not dialyzed (group 2a), and six required dialysis (group 2b). Group 1 patients presented with mild hypocalcemia (mean +/- SD serum ionized calcium, 1.18 +/- 0.05 vs. 1.23 +/- 0.02 mmol/L in controls; P = 0.01) that persisted until discharge in the presence of normal serum phosphate, PTH, and vitamin D metabolite levels. Group 2 patients were more hypocalcemic on admission (1.10 +/- 0.08 mmol/L; P < 0.0001 vs. controls), especially those in group 2b whose serum ionized calcium fell to 0.88 +/- 0.13 mmol/L when renal dysfunction was maximal. In group 2 patients, the admission serum PTH level was raised (5.4 +/- 3.8 vs. 2.7 +/- 0.9 pmol/L in controls; P < 0.02) and changed reciprocally with calcemia. Significant rises in serum phosphate occurred only in group 2b patients who had depressed serum free 1,25-dihydroxyvitamin D levels throughout. Hypercalcemia did not accompany the diuretic phase of ARF. These data suggest that parathyroid gland dysfunction is a cause of hypocalcemia in severe malaria without ARF, as seen in group 1 patients; in patients with ARF, the effect of the combination of phosphate retention and altered vitamin D metabolism on skeletal PTH sensitivity is of prime significance.


Asunto(s)
Lesión Renal Aguda/etiología , Lesión Renal Aguda/metabolismo , Homeostasis , Malaria Falciparum/complicaciones , Minerales/metabolismo , Lesión Renal Aguda/fisiopatología , Adolescente , Adulto , Calcio/sangre , Creatina Quinasa/sangre , Femenino , Hemoglobinas/análisis , Humanos , Riñón/fisiopatología , Hígado/fisiopatología , Masculino , Persona de Mediana Edad , Mioglobinuria/orina , Hormona Paratiroidea/sangre , Fosfatos/sangre , Vitamina D/metabolismo
5.
J Clin Endocrinol Metab ; 82(9): 3029-33, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9284738

RESUMEN

Patients with malaria can have features of adrenal insufficiency. Because of the pathophysiological and clinical implications of an Addisonian state, the hypothalamic-pituitary-adrenocortical axis was assessed in nine Vietnamese adults with complicated malaria. A CRH test was performed on admission (in convalescence in five cases) and in six healthy controls. Basal plasma ACTH concentrations in the patients and controls were similar [median (range): 2.9 (0.2-9.7) vs. 3.5 (1.9-13.4) pmol/L, respectively; P > 0.1]. Serum cortisol levels were greater in the patients [882 (294-1682) vs. 190 (110-676) nmol/L; P < 0.01], but three (33%) had values within the control range. Basal serum corticosteroid-binding globulin concentrations were similar in patients and controls (P = 0.23). The post-CRH rise in plasma ACTH was attenuated in the patients [peak: 6.1 (0.9-23.2) vs. 14.5 (6.2-21.5) pmol/L in controls; P < 0.05]; basal and peak plasma ACTH correlated with plasma interleukin-6 in this group (rs > or = 0.60; P < or = 0.04). Serum cortisol responses to CRH were depressed in acute illness [peak 990 (394-1, 805) nmol/L or 10 (0-50%) above baseline vs. 500 (429-703) nmol/L or 160 (10-380%) in controls; P < 0.05]. The median estimated serum cortisol t1/2 was 4.6 h in the patients and 1.6 h in the controls. These data suggest that, relative to a normal stress response, primary and secondary adrenal insufficiency can occur in severe malaria but may be attenuated by increased circulating interleukin-6 concentrations and impaired cortisol metabolism. The benefits of stress-dose corticosteroid replacement are unknown but could be considered in hypoglycemic patients or those with a serum cortisol within or below the reference range.


Asunto(s)
Citocinas/fisiología , Sistema Hipotálamo-Hipofisario/fisiopatología , Malaria Falciparum/fisiopatología , Sistema Hipófiso-Suprarrenal/fisiopatología , Hormona Adrenocorticotrópica/sangre , Adulto , Hormona Liberadora de Corticotropina , Citocinas/sangre , Femenino , Humanos , Hidrocortisona/sangre , Malaria Falciparum/sangre , Malaria Falciparum/diagnóstico , Masculino , Persona de Mediana Edad , Nitratos/sangre , Hormonas Tiroideas/sangre
6.
Neuroscience ; 116(1): 13-7, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12535932

RESUMEN

Activation of the extracellular signal-related kinase is important for long-term increases in synaptic strength in the Aplysia nervous system. However, there is little known about the mechanism for the activation of the kinase in this system. We examined the activation of Aplysia extracellular signal-related kinase using a phosphopeptide antibody specific to the sites required for activation of the kinase. We found that phorbol esters led to a prolonged activation of extracellular signal-related kinase in sensory cells of the Aplysia nervous system. Surprisingly, inhibitors of protein kinase C did not block this activation. Serotonin, the physiological transmitter involved in long-term synaptic facilitation, also led to prolonged activation of extracellular signal-related kinase, but inhibitors of protein kinase A or protein kinase C did not block this activation. We examined whether the protein synthesis-dependent increase in excitability stimulated by phorbol esters was dependent on phorbol ester activation of extracellular signal-related kinase, but increases in excitability were still seen in the presence of inhibitors of extracellular signal-related kinase activation. Our results suggest that prolonged phosphorylation of extracellular signal-related kinase in the Aplysia system is not mediated by either of the classic second messenger activated kinases in this system, protein kinase A or protein kinase C and that extracellular signal-related kinase is not important for phorbol ester induced long-term effects on excitability.


Asunto(s)
Aplysia , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Sistema Nervioso/efectos de los fármacos , Sistema Nervioso/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Proteína Quinasa C/metabolismo , Serotonina/metabolismo , Animales , Western Blotting , AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Activadores de Enzimas/farmacología , Inmunohistoquímica , Ésteres del Forbol/farmacología , Proteína Quinasa C/antagonistas & inhibidores , Transducción de Señal/efectos de los fármacos
7.
DNA Cell Biol ; 16(3): 347-56, 1997 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9115644

RESUMEN

Voltage-gated Na+ channels generate the depolarizing inward current that is critical for the initiation and conduction of action potentials. To study the roles of Na+ channels in neuronal signaling, we have begun the molecular analysis of Na+ channels in Aplysia californica. We have isolated cDNAs that encode a neuronal Na+ channel alpha-subunit, which we have named SCAP1. DNA sequence analysis of the SCAP1 cDNA revealed an open reading frame that predicts a protein of 1,993 amino acids, which is highly similar to other members of the Na+ channel alpha-subunit gene family. RNase protection assays carried out on various Aplysia tissues indicated that SCAP1 is expressed predominantly in the nervous system. All of the nonneuronal tissues tested were negative with the exceptions that low levels of expression were observed in ovotestis and parapodium, probably due to the presence of small numbers of neurons within these tissue preparations. Southern blot hybridization at reduced stringency indicated that the genome of Aplysia contains more than one Na+ channel alpha-subunit gene.


Asunto(s)
Aplysia/genética , ADN Complementario/genética , Canales de Sodio/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Regulación de la Expresión Génica , Datos de Secuencia Molecular , Alineación de Secuencia
8.
J Virol Methods ; 60(2): 161-70, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8844622

RESUMEN

Human immunodeficiency virus type 1 (HIV-1) is transmitted by infected males in semen. However, the inoculum required for infection is unknown. The ability to collect such information will rely on the availability of reliable quantitative assays of HIV-1 in semen. We examined the comparative performance of NASBA and Amplicor Monitor RT-PCR in quantifying HIV-1 RNA in cell free seminal plasma from seropositive men and correlated the results obtained with viral titres measured by a seminal cell quantitative microculture (QMC) assay. Of samples analysed, 68% and 56% by both NASBA and RT-PCR contained measurable HIV-1 RNA, respectively. Amplification inhibition frequently affected RT-PCR but not NASBA. Excluding samples with complete RT-PCR inhibition, there was 90% qualitative concordance and a strong positive correlation (r = 0.86) of RNA levels measured by the two methods. Comparison of the concentration of HIV-1 RNA in seminal plasma samples, as measured by NASBA, with QMC viral titres indicated that RNA levels probably reflect the infectiousness of whole semen. NASBA is a reliable technique for quantitating HIV-1 RNA in seminal plasma and should become a valuable tool in the study of factors that influence the sexual transmission of HIV.


Asunto(s)
Infecciones por VIH/virología , VIH-1/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , ARN Viral/aislamiento & purificación , Semen/virología , Carga Viral/métodos , Estudios de Evaluación como Asunto , VIH-1/genética , Humanos , Masculino , Técnicas de Amplificación de Ácido Nucleico , ARN Viral/genética , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
9.
J Am Diet Assoc ; 86(6): 752-8, 1986 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-3519737

RESUMEN

Nutrition counselors in the Multiple Risk Factor Intervention Trial (MRFIT) were able to help middle-aged men who were at high risk for coronary heart disease change their dietary habits, maintain those changes over time, and decrease their serum cholesterol levels. Most of a 7.5% mean serum cholesterol reduction achieved after 6 years of nutrition intervention occurred during the first year of the trial and was thereafter sustained. Total cholesterol and low-density lipoprotein cholesterol fraction decreases indicated improvement in terms of coronary heart disease risk. The food record rating, a numerical, semi-objective adherence technique that assesses a 3-day food record with respect to lipid-lowering potential, was used throughout the trial to measure adherence to recommended food patterns. Participants with lower food record rating scores, which indicate better adherence, demonstrated greater reductions in serum total cholesterol, plasma total cholesterol, and low-density lipoprotein fraction cholesterol determinations on a group basis. Subjective evaluations of the suitability of home and working environments, evidence of deviation from the MRFIT food patterns, and overall nutrition program motivation also showed that as ratings in each category became more favorable, lower food record rating scores and greater blood lipid reductions were consistently observed. The subgroup of participants who were non-smokers and not hypertensive demonstrated greater lipid responses and better dietary adherence. Continued smoking and antihypertensive medications appeared to adversely influence dietary adherence and/or lipid reductions. The MRFIT experience, however, demonstrated for the first time that dietary changes and blood lipid reductions can be achieved after the initial intervention effect, despite a continued emphasis on high blood pressure management and smoking cessation.


Asunto(s)
Enfermedad Coronaria/prevención & control , Dieta , Conducta Alimentaria , Lípidos/sangre , Cooperación del Paciente , Colesterol/sangre , HDL-Colesterol/sangre , LDL-Colesterol/sangre , VLDL-Colesterol , Ensayos Clínicos como Asunto , Ingestión de Energía , Métodos Epidemiológicos , Humanos , Hipertensión/complicaciones , Lipoproteínas VLDL/sangre , Masculino , Persona de Mediana Edad , Distribución Aleatoria , Riesgo , Fumar
10.
J Infect ; 30(2): 147-51, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7636281

RESUMEN

Cytomegalovirus (CMV) is an increasingly important opportunistic pathogen in patients with HIV infection and advanced immune deficiency. Neurological complications due to CMV cause significant morbidity but may be treatable with specific anti-viral therapy: cerebral mass lesions are not a generally recognised manifestation. We report two patients with CMV encephalitis presenting as a cerebral mass lesion, with simultaneous occurrence of a pleuro-pulmonary mass also caused by CMV in one case, and with concurrent polyradiculomyelopathy in the other. The spectrum of previously reported clinical and radiological features of CNS involvement in AIDS is discussed. CMV should be considered in the differential diagnosis of cerebral mass lesions in patients with HIV infection and severe immune deficiency so that anti-viral therapy can be rapidly deployed.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/virología , Encefalopatías/virología , Infecciones por Citomegalovirus/virología , Infecciones Oportunistas Relacionadas con el SIDA/diagnóstico por imagen , Adulto , Encefalopatías/diagnóstico por imagen , Infecciones por Citomegalovirus/diagnóstico por imagen , Diagnóstico Diferencial , Seropositividad para VIH/complicaciones , Homosexualidad Masculina , Humanos , Masculino , Tomografía Computarizada por Rayos X
11.
J Infect ; 31(3): 181-8, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8586836

RESUMEN

In order to examine the effects of platelet-activating factor (PAF) in complicated Plasmodium falciparum infections, plasma concentrations of lyso-PAF, stable metabolite and principal precursor of PAF, were measured in 25 Vietnamese adults with severe malaria. The concentration of PAF in the cerebrospinal fluid (CSF) was determined in a sub-group of 23 comatose patients and, together with that of lyso-PAF, in the plasma of 20 patients on recovery of consciousness. The concentration of lyso-PAF in the plasma was depressed on admission to hospital (median [range]; 21 [8-143] vs. 293 [215-410] ng/ml in 10 controls; P < 0.001). There was, however, no change in plasma activity of acetylhydrolase which converts PAF to lyso-PAF (P > 0.01 vs. controls) while simultaneous reduction in the concentration of lipoproteins associated with lyso-PAF were less than those of lyso-PAF per se in the plasma. The plasma concentration of lyso-PAF on admission was associated with parasitaemia and the concentration of serum triglycerides (rs = -0.42, P = 0.04 in each case), the latter being consistent with hepatic effects of PAF reported in previous studies. CSF concentrations of PAF on admission were low (2.3 [0.5-7.7] vs. 0.9 [0-2.5] ng/ml after recovery, P < 0.01) compared with values reported previously in bacterial meningitis. Plasma concentrations of lyso-PAF after recovery lay between admission and control values. While increased availability of PAF may reflect parasite burden and may modulate liver-mediated metabolic disturbances such as hypoglycaemia and lactic acidosis, the role of PAF in cerebral malaria is uncertain.


Asunto(s)
Malaria Cerebral/metabolismo , Malaria Falciparum/metabolismo , Factor de Activación Plaquetaria/análogos & derivados , Factor de Activación Plaquetaria/metabolismo , Adulto , Antimaláricos/uso terapéutico , Colesterol/sangre , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Coma/metabolismo , Femenino , Humanos , Unidades de Cuidados Intensivos , Metabolismo de los Lípidos , Malaria Cerebral/tratamiento farmacológico , Malaria Falciparum/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Factor de Activación Plaquetaria/líquido cefalorraquídeo , Vietnam/etnología , Australia Occidental
17.
Infect Control Hosp Epidemiol ; 29(9): 859-65, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18684094

RESUMEN

OBJECTIVE: To describe an outbreak of invasive methicillin-resistant Staphylococcus aureus (MRSA) infection after percutaneous needle procedures (acupuncture and joint injection) performed by a single medical practitioner. SETTING: A medical practitioner's office and 4 hospitals in Perth, Western Australia. PATIENTS: Eight individuals who developed invasive MRSA infection after acupuncture or joint injection performed by the medical practitioner. METHODS: We performed a prospective and retrospective outbreak investigation, including MRSA colonization surveillance, environmental sampling for MRSA, and detailed molecular typing of MRSA isolates. We performed an infection control audit of the medical practitioner's premises and practices and administered MRSA decolonization therapy to the medical practitioner. RESULTS: Eight cases of invasive MRSA infection were identified. Seven cases occurred as a cluster in May 2004; another case (identified retrospectively) occurred approximately 15 months earlier in February 2003. The primary sites of infection were the neck, shoulder, lower back, and hip: 5 patients had septic arthritis and bursitis, and 3 had pyomyositis; 3 patients had bacteremia, including 1 patient with possible endocarditis. The medical practitioner was found to be colonized with the same MRSA clone [ST22-MRSA-IV (EMRSA-15)] at 2 time points: shortly after the first case of infection in March 2003 and again in May 2004. After the medical practitioner's premises and practices were audited and he himself received MRSA decolonization therapy, no further cases were identified. CONCLUSIONS: This outbreak most likely resulted from a breakdown in sterile technique during percutaneous needle procedures, resulting in the transmission of MRSA from the medical practitioner to the patients. This report demonstrates the importance of surveillance and molecular typing in the identification and control of outbreaks of MRSA infection.


Asunto(s)
Terapia por Acupuntura/efectos adversos , Brotes de Enfermedades , Transmisión de Enfermedad Infecciosa de Profesional a Paciente , Inyecciones/efectos adversos , Resistencia a la Meticilina , Infecciones Estafilocócicas , Staphylococcus aureus/efectos de los fármacos , Adulto , Anciano , Antibacterianos/administración & dosificación , Antibacterianos/uso terapéutico , Artritis Infecciosa/terapia , Femenino , Personal de Salud , Humanos , Control de Infecciones/métodos , Masculino , Persona de Mediana Edad , Piomiositis/terapia , Articulación del Hombro/efectos de los fármacos , Articulación del Hombro/microbiología , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/epidemiología , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/transmisión , Staphylococcus aureus/clasificación , Staphylococcus aureus/genética , Staphylococcus aureus/aislamiento & purificación , Australia Occidental/epidemiología
18.
J Neurochem ; 75(2): 872-81, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10899966

RESUMEN

We have used an antibody that specifically recognizes eukaryotic initiation factor 4E (eIF4E) when it is phosphorylated at Ser(207) to characterize eIF4E phosphorylation in the nervous system of APLYSIA: The level of phosphorylated eIF4E, but not the level of total eIF4E, was significantly correlated with the basal rate of translation measured from different animals. Serotonin (5-HT), a transmitter that regulates the rate of translation in APLYSIA: neurons, had mixed effects on eIF4E phosphorylation. 5-HT decreased eIF4E phosphorylation in sensory cell clusters through activation of protein kinase C. 5-HT increased eIF4E phosphorylation in the whole pleural ganglia. In the APLYSIA: nervous system, eIF4E phosphorylation correlated with phosphorylation of the p38 MAP kinase, but not the p42 MAP kinase (ERK). Furthermore, an inhibitor of the p38 MAP kinase significantly decreased basal eIF4E phosphorylation, but an inhibitor of the MAP or ERK kinase (MEK) did not. Despite the correlation of eIF4E phosphorylation with the basal rate of translation, inhibition of eIF4E phosphorylation by an inhibitor of the p38 MAP kinase did not significantly decrease the rate of translation.


Asunto(s)
Ganglios de Invertebrados/fisiología , Neuronas/fisiología , Factores de Iniciación de Péptidos/metabolismo , Biosíntesis de Proteínas , Alcaloides , Animales , Aplysia , Benzofenantridinas , Colforsina/farmacología , AMP Cíclico/análogos & derivados , AMP Cíclico/farmacología , Inhibidores Enzimáticos/farmacología , Factor 4E Eucariótico de Iniciación , Técnicas In Vitro , Cinética , Metionina/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Neuronas/efectos de los fármacos , Fenantridinas/farmacología , Forbol 12,13-Dibutirato/farmacología , Fosforilación , Serotonina/farmacología , Tionucleótidos/farmacología , Proteínas Quinasas p38 Activadas por Mitógenos
19.
J Nutr ; 121(10): 1548-53, 1991 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1765818

RESUMEN

This experiment examined the time course over which the amount of dietary essential fatty acids (EFA) affects brain mitochondrial fatty acids. Weanling rats were fed 20% (wt/wt) fat diets that contained either 4 or 15% (wt/wt of diet) EFA for 1, 2, 3 or 6 wk or a 10% EFA diet for 3 or 6 wk. The EFA ratio [18:2(n-6)/18:3(n-3)] of all diets was approximately 30. Fatty acid analysis of brain mitochondrial phosphatidylethanolamine, phosphatidylcholine and cardiolipin revealed that the largest dietary effect was on 18:2(n-6), which was 30% higher in rats fed the 15 vs. 4% EFA diets after 1 wk. This difference increased to twofold by 3 wk and was still twofold after 6 wk. These results demonstrate several facts: 1) the response of 18:2(n-6) in cardiolipin to dietary EFA is very fast and large, relative to changes in other quantitatively major fatty acids observed in weanling rats; 2) the 18:2(n-6) level in neural cardiolipin stabilizes after 3 wk of feeding at a level dependent upon the amount of dietary EFA; and 3) at least one neural fatty acid, 18:2(n-6), is very sensitive to amounts of dietary EFA that are well above the animal's EFA requirement.


Asunto(s)
Encéfalo/metabolismo , Ácidos Grasos Esenciales/administración & dosificación , Mitocondrias/metabolismo , Animales , Peso Corporal/efectos de los fármacos , Encéfalo/efectos de los fármacos , Cardiolipinas/metabolismo , Dieta , Ingestión de Energía , Ácidos Grasos Esenciales/farmacología , Masculino , Mitocondrias/efectos de los fármacos , Tamaño de los Órganos/efectos de los fármacos , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas/metabolismo , Ratas , Ratas Endogámicas
20.
Neurochem Res ; 13(6): 517-23, 1988 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2970016

RESUMEN

The methionine (MET) derivative, S-adenosylmethionine (SAM), provides methyl-groups for methylation reactions in many neural processes. In rats made diabetic with streptozotocin (SZ), brain SAM levels were generally lower (10-20%) than in controls, with a constant decrease being observed five weeks after onset of diabetes. This decrease in SAM levels may be due to reduced precursor (MET) availability because greatly elevating plasma MET concentrations in SZ diabetic rats by dietary manipulation increased their neural SAM concentrations to be approximately or even greater than (5-20%) those of controls. In contrast, neural levels of SAM's demethylated product, S-adenosylhomocysteine (SAH), were reduced to a greater extent (17-44%) than SAM levels in all groups of SZ diabetic rats independent of their plasma MET concentrations or brain SAM levels. This indicates that the decrease in SAH levels is not simply due to substrate (SAM) restriction. These changes in MET metabolites appear to be a general effect of diabetes rather than a non-pancreatic side-effect of SZ, because genetically diabetic BB Wistar rats also exhibited reduced brain SAM (25%) and brain SAH (46%) levels. These results indicate that methyl-groups from MET are handled differently in the brain of the diabetic rat, which considering the variety and importance of neural methylation reactions, could have important consequences for the diabetic.


Asunto(s)
Encéfalo/metabolismo , Diabetes Mellitus Experimental/metabolismo , Homocisteína/análogos & derivados , Metionina/sangre , S-Adenosilhomocisteína/metabolismo , S-Adenosilmetionina/metabolismo , Administración Oral , Animales , Caseínas/administración & dosificación , Dieta , Femenino , Masculino , Ratas , Ratas Endogámicas , Estreptozocina , Factores de Tiempo
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