RESUMEN
BACKGROUND: Elite controllers are able to control viral replication without antiretroviral therapy. Exceptional elite controllers do not show disease progression for more than 25 years. Different mechanisms have been proposed and several elements of both innate and adaptive immunity are implicated. Vaccines are immune stimulating agents that can promote HIV-RNA transcription; transient plasma HIV-RNA detectability has been described within 7-14 days after different vaccinations. The most reliable mechanism involved in virosuppressed people living with HIV is a generalized inflammatory response that activates bystander cells harboring latent HIV. So far no data about viral load increase in elite controllers after SARS-CoV-2 vaccination are reported in literature. CASE PRESENTATION: We report the case of a 65-year-old woman of European ancestry, diagnosed with HIV-1/HCV co-infection more than 25 years ago. Since then, HIV-RNA remained undetectable and she never received ARV therapy. In 2021 she was vaccinated with mRNA-BNT162b2 vaccine (Pfizer-BioNTech®). She was administered with three doses in June, July and October 2021, respectively. The last available viral load was undetectable in March 2021. We observed an increase of VL at 32 cp/ml and 124 cp/mL, two and seven months after the second vaccine dose, respectively. During monthly follow-up, HIV-RNA gradually and spontaneously dropped becoming undetectable without ARV intervention. COVID-19 serology was positive with IgG 535 BAU/mL, showing response to vaccination. We measured total HIV-DNA at different time-points and we found it detectable both at the time of the higher plasma HIV-RNA (30 cp/10^6 PBMCs) and when it was undetectable (13 cp/10^6 PBMCs), in reduction. CONCLUSIONS: This case is the first report, to our knowledge, describing a rebound of plasma HIV-RNA in an elite controller after three doses of mRNA-BNT162b2 vaccine for SARS-CoV-2. Concomitantly with a spontaneous reduction of plasma HIV-RNA ten months after the third dose of mRNA-BNT162b2 vaccine (Pfizer-BioNTech®) without antiretroviral therapy intervention, we observed a reduction of total HIV-DNA in peripheral mononuclear cells. The potential role of vaccinations in altering HIV reservoir, even in elite controllers when plasma HIV-RNA is undetectable, could be a valuable aspect to take into account for the future HIV eradication interventions.
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COVID-19 , Infecciones por VIH , Seropositividad para VIH , VIH-1 , Femenino , Humanos , Anciano , Infecciones por VIH/tratamiento farmacológico , Vacunas contra la COVID-19 , Vacuna BNT162 , SARS-CoV-2 , COVID-19/prevención & control , Latencia del Virus , Vacunación , Controladores de Élite , ARN MensajeroRESUMEN
PURPOSE: Data on the frequency of HCV naturally occurring drug-resistant variants (RAVs) at baseline in HIV/HCV coinfected patients are scarce. METHODS: NS3-HCV RAVs were studied by full-population direct sequencing from plasma specimens of 345 DAA-naïve patients with HCV chronic hepatitis (159 of them with HIV/HCV-coinfection). RESULTS: NS3 RAVs were identified in 31.5 % of patients, with a significant proportion of HIV/HCV coinfected DAA-naïve patients compared to those with HCV monoinfection (38 vs. 25 % p = 0.0104, OR 1.84; 95 % CI 1.162-2.916). CONCLUSIONS: HCV resistance genotyping test before treatment may be worth in special populations such as HIV/HCV coinfection to optimize patient treatment.
Asunto(s)
Infecciones por VIH/complicaciones , Hepacivirus/genética , Hepatitis C/complicaciones , Hepatitis C/virología , Proteínas no Estructurales Virales/genética , Antivirales , Estudios de Cohortes , Coinfección , Femenino , Genotipo , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Dengue fever is growing at a global level both as number of cases and as geographic area of endemicity. Italy is not in endemic area, but the competent vector Aedes albopictus is widespread in this country, so that the possibility of introduction of the infection cannot be ruled out. We retrospectively collected demographic, clinical, and laboratory data about consecutive cases diagnosed in Torino and Negrar-Verona in the period 2010-2015. One hundred thirteen cases of dengue were observed, with an increasing trend during years. The infection was imported mostly from south-east Asia, but the risk appears to be higher in Latin America. More than half of the patients were admitted to the hospital but only one case of severe dengue was observed. Many patients presented after the resolution of symptoms. Rapid diagnostic tests were done in the majority of patients and allowed a diagnosis both in the acute (NS1 antigen) and convalescent (IgMantibodies) phases of the disease. An early diagnosis is paramount to avoid the spreading of the infection.
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Dengue/diagnóstico , Pruebas Diagnósticas de Rutina/métodos , Dengue/epidemiología , Diagnóstico Precoz , Humanos , Italia/epidemiología , Estudios Retrospectivos , Centros de Atención Terciaria , Factores de Tiempo , ViajeRESUMEN
AIM: Quantitative polymerase chain reaction (PCR) analysis to evaluate virus load in comparison with the patient's base-line virus levels would be an optimal diagnostic approach to monitoring human polyomavirus infections and to investigate their possible involvement in the onset of nephropathy in this patient group. Studies on the correlation between viral burden and renal disease have pointed to the incidence of JC virus (JCV) related progressive multifocal leukoencephalopathy (PML) occurring in renal and haematopoietic stem cell transplant recipients. METHODS: We developed a reliable internally-controlled quantitative PCR assay to measure JCV-DNA in fluid samples of urine, serum and cerebrospinal fluid (CSF) by densitometric analysis of the amplification products. The assay was also used to evaluate the JCV load in CFS samples from patients with suspected demyelinating syndrome and in urine and serum samples from healthy subjects and renal transplant recipients. RESULTS: All CSF samples from the 51 patients with suspected demyelinating syndrome tested JCV-DNA negative: none of them had a diagnosed PML. Analysis of the prevalence of JCV-viruria and JCV-viraemia confirmed our previous data. JCV-viruria was detected in 17% of renal transplant recipients and 26.6% of healthy controls; JCV-viraemia was found in 3.4% of transplant patients and 0% in controls. Noteworthy was a lower prevalence of JCV-viraemia in the 116 (3.4%) renal transplant patients than the prevalence previously reported for the 51 (11.8%) patients with suspected demyelinating syndrome. The mean viral load of viruria was much higher in the healthy controls than in the transplant recipients [104020 DNA copies/mL (DS+/-62284) vs 4136 DNA copies/mL (DS+/-77371)]. CONCLUSIONS: The quantitative PCR assay developed in our lab offers in 2 h time a reliable true quantification of viral DNA by densitometric analysis of the amplification product. To check for the possible presence of potential Taq polymerase inhibitors an internal control (the homemade pJCV-C plasmid) is used. The relation between polyomavirus infections and their possible involvement in post-transplant pathologies need further investigation. It would be useful to monitor the JCV-DNA load in urine and serum from more renal transplant recipients, including patients with nephropathy or active graft rejection over a longer period of time.
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ADN Viral/genética , Virus JC/genética , Reacción en Cadena de la Polimerasa/métodos , Secuencia de Bases , Estudios de Casos y Controles , ADN Viral/análisis , ADN Viral/líquido cefalorraquídeo , Humanos , Virus JC/aislamiento & purificación , Trasplante de Riñón , Leucoencefalopatía Multifocal Progresiva/virología , Reacción en Cadena de la Polimerasa/normasRESUMEN
A single oral dose (430 mg/kg) of atrazine, a widely employed s-triazine herbicide, was administered to young male rats. There was a significant increase of the in vivo elimination of hexobarbital and a significant induction of the activity of 7-pentoxyresorufin-O-dealkylase, while cytochrome P-450 content and other mixed function oxidase activities remained unaltered. The administration of carbon tetrachloride (CCl4) to atrazine pretreated rats did not substantially augment the impairment of drug metabolizing enzymes brought about by CCl4 alone. Results suggest that atrazine behaves like a relatively weak inducer of phenobarbital-inducible families of cytochrome P-450.
Asunto(s)
Atrazina/toxicidad , Tetracloruro de Carbono/toxicidad , Sistema Enzimático del Citocromo P-450/biosíntesis , Hígado/efectos de los fármacos , Animales , Atrazina/metabolismo , Citocromo P-450 CYP1A1 , Citocromo P-450 CYP2B1 , Inducción Enzimática/efectos de los fármacos , Glutatión/metabolismo , Hígado/metabolismo , Masculino , Oxidorreductasas/biosíntesis , Fenobarbital/farmacología , Ratas , Ratas WistarRESUMEN
The toxicity of Atrazine and that of its Desethylatrazine metabolite has been defined employing two organisms already tested in our labs the Dugesia gonocephala, belonging to a scissiparous strain coming from the island of Tavolara (Sardinia) and the Thamnocephalus platyurus, crustacean anostracan produced under form of quiescent cysts from Creasel Ltd. (Deinze, Belgium). It has been defined the lethal concentrations at 50% of Atrazine and of Desethylatrazine, of which it has been studied also the report dose-effect in the comparisons of the rectilinear motility. The results highlight that in the comparisons of the T. platyurus Atrazine expounds a toxicity of around three times that of its metabolite; this is not seen with the Planarians that are equally sensitive to both the compounds. The use of these two experimental models for the evaluation of the contamination of bodies of water is shown to be particularly useful given their great sensitivity to pollutants.
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Atrazina/análogos & derivados , Atrazina/toxicidad , Decápodos/efectos de los fármacos , Herbicidas/toxicidad , Residuos de Plaguicidas/toxicidad , Planarias/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Animales , Relación Dosis-Respuesta a Droga , Italia , Dosificación Letal Mediana , Locomoción/efectos de los fármacos , Especificidad de la Especie , Contaminación del AguaRESUMEN
In spring and autumn 1994 and 1995 affluent water and bed sediment were sampled from 24 tributaries of the Po river, always at the same site and at the nearest place to the confluence. In the laboratory the pore water was separated from the particle fraction of the sediment. The organic compounds bound to the latter component were extracted with solvents and brought to water solution by means of dimethyl sulfoxide. The observed animal species, along with the seeds of Lepidium, were exposed to effluent water, to pore water and to water solutions of the organic compounds extracted from bed sediment. Toxicity was evaluated on the basis of 1) direct lethality, 2) the delay of embryo development, 3) the impairment of regeneration, in the animal species, while the germination index was used for the Lepidium susceptibility. The results of these investigations demonstrate that 1) the challenged species cover a broad range of sensitivities toward environmental toxins, 2) toxicity found in river samples appears almost exclusively bound to the sediment, 3) the noxious effects found in the tributaries of the Po river increase moving downstream, and 4) likewise the sediment-bound toxicity varies among the different samplings, both as a consequence of changes in rain-dependent river flow, and because of the man-made interventions on the river sides and bed.
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Suelo/análisis , Contaminación del Agua , Animales , Artemia/efectos de los fármacos , Bioensayo , Decápodos/efectos de los fármacos , Agua Dulce/análisis , Italia , Planarias/efectos de los fármacos , Erizos de Mar/efectos de los fármacos , Semillas/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Contaminantes del Agua/toxicidadRESUMEN
AIM: The neurofibromatosis type 1 (NF1) is an autosomal dominant neurocutaneous disease. In 40-70% of cases are described signal hyperintensity on MRI, called unidentified bright objects (UBO). Their correlation with clinical disorders is still debated. The present study investigated the correlation between the UBOs and neuropsychiatric outcomes overall, observes the long-term through the comparison of MRI brain and considers the utility of including MRI early in the investigation of NF1. METHODS: We included 100 patients (age 2-18 years) with NF1. The parents were given a medical questionnaire to fill, a clinical neurologic examination (Touwen) was performed and brain MRI were analyzed during the years. RESULTS: In 72% of cases were detected UBO's last MRI. It was observed that the UBO's tend to shrink over time and in some cases to disappear in pre-adolescent. There were significant correlations between UBOs and minor disturbances in motor function (P=0.004) and between UBO's and cognitive deficits (P=0.016). The 79.62% of the patients is followed by a specialist in neuropsychiatry, as correlated significantly (P=0.027) with changes on MRI. CONCLUSIONS: Given the correlation between UBO's, neurological disorders, cognitive and behavioral, suggest be included in the diagnostic protocol MRI brain areas as T2H can be considered predictive for a neuropsychiatric disorder.
Asunto(s)
Imagen por Resonancia Magnética , Trastornos Mentales/diagnóstico , Neurofibromatosis 1/diagnóstico , Neuroimagen , Adolescente , Niño , Preescolar , Femenino , Humanos , MasculinoAsunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Cloroformo/uso terapéutico , Hidrocarburos Halogenados/uso terapéutico , Alanina Transaminasa/sangre , Animales , Aspartato Aminotransferasas/sangre , Bromo/uso terapéutico , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Interacciones Farmacológicas , Hígado Graso/inducido químicamente , Hidrocarburos Halogenados/antagonistas & inhibidores , Hidrocarburos Halogenados/toxicidad , Metabolismo de los Lípidos , Masculino , Microsomas Hepáticos/metabolismo , Necrosis , Peróxidos/biosíntesis , Fenobarbital/uso terapéutico , Fenilendiaminas/uso terapéutico , Proadifeno/uso terapéutico , Ratas , Espectrofotometría Ultravioleta , Factores de Tiempo , Triglicéridos/metabolismoAsunto(s)
Intoxicación por Tetracloruro de Carbono/metabolismo , Ácidos Grasos/metabolismo , Microsomas Hepáticos/metabolismo , Fosfolípidos/metabolismo , Animales , Ácidos Araquidónicos/metabolismo , Cromatografía de Gases , Cromatografía en Capa Delgada , Ayuno , Ácidos Grasos Esenciales/metabolismo , Femenino , Cinética , Metabolismo de los Lípidos , Hígado/metabolismo , Ratas , Triglicéridos/metabolismoRESUMEN
Experimental work in our laboratory has confirmed the protective activity of vanadium compounds on hyperglycemia and glycosuria in streptozotocin (STZ) diabetes. Furthermore, diabetic cataract has also been partially prevented. Nevertheless, the combination of a natural antioxidant, vitamin E, with Na3 VO4 has not further enhanced this ameliorating effect. Our experimental approach has been an attempt to block the prooxidant activity of both STZ and vanadate, with the purpose of eliciting the best possible antidiabetic protection. More recently, a lipid soluble synthetic antioxidant U-78517F, a 2-methylaminochroman, has been reported to have a significant protective effect against brain injury and ischemia. This compound inhibits the iron-dependent lipid peroxidation 100 times more effectively than vitamin E. This investigation has introduced a combination of the vanadium compound plus the aforesaid lazaroid, as its (-) enantiomer, U-83836E, in order to improve the insufficient protection when vitamin E was used. For twelve weeks, male Wistar rats, rendered diabetic with STZ, were administered Na3VO4 in drinking water along with the lazaroid carried by the food. Four, eight and twelve weeks after the beginning of the protective treatment, fluid and food intake, diuresis and excreted feces, glycosuria and proteinuria were determined on biological samples obtained in metabolic cages; body weight and glycemia were also recorded. At weeks 6 and 12 of the treatment, the opaqueness of the eye lenses was controlled and registered. At the end of the experiment, circulating glycosylated hemoglobin (HbA1c), fructosamine, N-acetyl-beta-D-glucosaminidase (NAG), and fluorescent peroxides were evaluated. Within the first month of treatment, protection by the combination paralleled that elicited by vanadate alone. At subsequent steps, U-83836E significantly improved the protective effect of vanadate alone on polydipsia and polyuria, but especially on hyperglycemia and glycosuria. The further ameliorating effect of the lazaroid was also observed on HbA1c and NAG, and, most important, on the cataract. In conclusion, these findings demonstrate that the lazaroid U-83836E succeeds in further protecting the most important symptoms of diabetes treated with vanadate, and that this antioxidant acts effectively even when it is administered orally in food, in a non invasive manner.
Asunto(s)
Catarata/prevención & control , Cromanos/farmacología , Diabetes Mellitus Experimental/prevención & control , Piperazinas/farmacología , Vanadatos/farmacología , Acetilglucosaminidasa/sangre , Animales , Catarata/sangre , Catarata/inducido químicamente , Cromanos/administración & dosificación , Cromanos/uso terapéutico , Diabetes Mellitus Experimental/sangre , Quimioterapia Combinada , Depuradores de Radicales Libres , Fructosamina , Hemoglobina Glucada/análisis , Hexosaminas/sangre , Cristalino/efectos de los fármacos , Masculino , Peróxidos/sangre , Piperazinas/administración & dosificación , Piperazinas/uso terapéutico , Ratas , Ratas Wistar , Estreptozocina , Vanadatos/administración & dosificación , Vanadatos/uso terapéuticoRESUMEN
Experimental work from our laboratory has confirmed the protective power of vanadium compounds on hyperglycemia and glycosuria in streptozotocin (STZ) diabetes. Furthermore, the diabetic cataract too has been partially prevented. The protection slightly increased, when vanadium was administered in combination with vitamin E. This investigation has introduced a combination of Na3VO4 plus the lazaroid U-83836E, a liposoluble antioxidant much more efficacious than tocopherol, in order to improve the insufficient protection when vitamin E was used. Male Wistar rats, rendered diabetic with STZ, were treated for 12 weeks with Na3VO4 in drinking water, U-83836E carried by the food, or both. The most significant metabolic parameters (food and fluid intake, diuresis and excreted feces) were studied monthly by means of metabolic cages. Body weight, glycemia, glycosuria and proteinuria were also recorded. At week 6 and 12 of the treatment, the opaqueness of the eye lenses was controlled. Circulation glycosylated hemoglobin (HbA1c), fructosamine, N-acetyl-beta-D-glucosaminidase (NAG) and fluorescent peroxides were evaluated at the end of the experiment. After the first month of treatment U-83836E improved significantly the protective effect of vanadate alone on polydipsia and polyuria, but more efficiently on hyperglycemia and glycosuria. The further ameliorating effect of the lazaroid was observed also on HbA1c, NAG and, most important, on the cataract. In conclusion, these findings demonstrate that the lazaroid U-83836E succeeds in further protecting the most important symptoms of diabetes treated with vanadate, and that this antioxidant acts effectively even when it is administered per os, in a non invasive manner.
Asunto(s)
Antioxidantes/uso terapéutico , Catarata/prevención & control , Cromanos/uso terapéutico , Diabetes Mellitus Experimental/tratamiento farmacológico , Nefropatías Diabéticas/prevención & control , Piperazinas/uso terapéutico , Compuestos de Vanadio/uso terapéutico , Animales , Diabetes Mellitus Experimental/sangre , Nefropatías Diabéticas/sangre , Evaluación Preclínica de Medicamentos , Quimioterapia Combinada , Masculino , Ratas , Ratas WistarRESUMEN
Previous findings from our laboratory suggested a possible interaction of atrazine, bentazon and molinate with other environmental and/or occupational poisons. The aim of this research was to obtain further toxicological information by using phenobarbital-induced rats and to characterize the effects of these herbicides on the hepatic microsomal metabolism of xenobiotics. Acute experiments have shown that the LD50 is augmented by the barbiturate pretreatment when atrazine is used, remains unchanged in the case of bentazon, but is lowered when molinate is given. Recrystallized atrazine, in the absence of the wetting compounds, elicits the same acute toxicity found when animals are challenged with a commercial preparation. No significant sex-related differences have been observed. In long-term treatment with these toxicants, atrazine shortened the hexobarbital narcosis, but no effect was observed after administration of either bentazon or molinate. Further studies on hexobarbital sleeping time demonstrated that females are more susceptible than males to the narcotic effect of this compound. The induction-like effect of atrazine exposure has been confirmed, mainly in young animals. At the end of the sleeping time, the actual serum concentration of hexobarbital is practically the same, and is not related to the length of the sleeping time. The absence of behavioral alterations in the open field tests exclude possible neurological effects of the triazine herbicide. In conclusion, these data demonstrate that atrazine by itself induces the hepatic pharmacometabolic system, while its metabolites result less toxic than the parent compound. On the contrary, metabolic transformations render the toxic effects of bentazon more severe.
Asunto(s)
Atrazina/toxicidad , Azepinas/toxicidad , Benzotiadiazinas/toxicidad , Herbicidas/toxicidad , Hexobarbital/farmacología , Actividad Motora/efectos de los fármacos , Sueño/efectos de los fármacos , Tiocarbamatos , Factores de Edad , Animales , Atrazina/metabolismo , Femenino , Hexobarbital/metabolismo , Dosificación Letal Mediana , Masculino , Ratas , Factores SexualesRESUMEN
An experimental model for monitoring rat liver function during protracted exposure to hepatotoxic agents is proposed. Owing to their invasiveness, the models usually employed are appropriate for studying the mechanism of action of toxic substances, but do not allow the liver situation to be followed over the course of time. The need to sacrifice animals to determine liver triglycerides-one of the key parameters in the progress of toxic damage- reduces the possibility of following such progress in the same animals. This study describes the testing of a model for monitoring three basic parameters of liver injury: cytolysis, steatosis and metabolic deficiency of the liver. CCl4 has been chosen as model-hepatotoxin. Steatosis is determined by evaluating the triglyceride content of small specimens of liver, obtained through open-field biopsies, which appear to be representative of the whole liver. Fatty liver is paralleled by the block in Triton-induced hypertriglyceridaemia. Determination of serum triglycerides derives from a very poorly invasive technique which can be repeated several times. The combination of these tests with the assessment of both the cytolysis (ALT and SDH release into the circulation) and the impairment of the efficiency of liver microsomal enzymes (TMO clearance), seems to offer a reliable experimental procedure in predicting the hepatotoxic effect of xenobiotics.
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Hepatopatías/diagnóstico , Animales , Biopsia , Intoxicación por Tetracloruro de Carbono/diagnóstico , Enfermedad Hepática Inducida por Sustancias y Drogas , Hígado Graso/diagnóstico , Masculino , Tasa de Depuración Metabólica , Microsomas Hepáticos/metabolismo , Polietilenglicoles/farmacología , Ratas , Succinato Deshidrogenasa/sangre , Triglicéridos/sangre , Triglicéridos/metabolismo , Trimetadiona/metabolismoRESUMEN
Testis structure and functions were monitored in male Wistar rats chronically exposed to various levels of sodium selenite (Na2SeO3) in drinking water (4, 8 or 16 ppm). The most remarkable testicular changes were observed in the 16 ppm group: intertubular oedema, oligospermia, scattered foci of degenerated spermatids were found. In addition, marked changes in several specific enzymes of testicular cells occurred along with a significant reduction of mean-tubular-diameters, mean-tubular-areas and mean-tubular-perimeters. These results clearly demonstrate a testicular involvement during chronic exposure of the rat to selenium.
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Selenio/toxicidad , Testículo/efectos de los fármacos , Animales , Peso Corporal/efectos de los fármacos , Relación Dosis-Respuesta a Droga , L-Lactato Deshidrogenasa/metabolismo , Masculino , Tamaño de los Órganos/efectos de los fármacos , Ratas , Ratas Endogámicas , Ácido Selenioso , Testículo/enzimología , Testículo/patología , Factores de TiempoRESUMEN
Hepatic bovine microsomes were incubated with Zineb concentrations ranging from 2.5 mM to 2.5 microM. Only the higher concentrations of the fungicide (2.5 and 0.25 mM) elicited a sharp decline in cytochrome P450, cytochrome b5 and total sulphydryl groups content as well as in the activities of NADPH cytochrome c reductase, aminopyrine N-demethylase and aniline 4-hydroxylase. The loss of cytochrome P450 was matched by a concomitant increase in the amount of cytochrome P420, which represents a catalytically inactive form of cytochrome P450. The same concentrations of the fungicide, either alone or in the presence of NADPH 1 mM, failed to increase the amount of thiobarbituric reactive substances with respect to control incubations, thereby excluding the possibility of lipid peroxidation as a contributing factor in the loss of cytochrome P450 and in the inhibition of cytochrome P450-mediated metabolism. It is concluded that Zineb can depress monooxygenase activity in bovine hepatic microsomes mainly through the denaturation of cytochrome P450 and the impaired transfer of reducing equivalents to the complex cytochrome P450-substrate. These mechanisms might also account for the inhibition in lipid peroxidation brought about by the fungicide.
Asunto(s)
Fungicidas Industriales/toxicidad , Peroxidación de Lípido/efectos de los fármacos , Microsomas Hepáticos/efectos de los fármacos , Zineb/toxicidad , Aminopirina N-Demetilasa/antagonistas & inhibidores , Anilina Hidroxilasa/antagonistas & inhibidores , Animales , Bovinos , Inhibidores Enzimáticos del Citocromo P-450 , Citocromos/metabolismo , Citocromos b5/antagonistas & inhibidores , Microsomas Hepáticos/enzimología , NADPH-Ferrihemoproteína Reductasa/antagonistas & inhibidores , Compuestos de Sulfhidrilo/análisisRESUMEN
The effects of subchronic administration (90 d) of zineb were studied in male New Zealand White rabbits. Rabbits were allotted to 3 groups of 8 animals each and offered diets containing 0, 0.3 or 0.6% zineb. A marked decline in weight gain, hemoglobin concentration, hematocrit, and erythrocyte and leucocyte counts occurred at the highest zineb dosage. There was a dose-related depression in circulating thyroid hormones, whereas serum lipid concentration, particularly that of cholesterol and triglycerides, increased. Hepatic lipid concentration was considerably reduced in rabbits exposed to 0.6% zineb. Neither serum testosterone nor the activities of selected testicular enzymes showed changes suggestive of testicular involvement. Pathological changes were in agreement with biochemical findings; there was a marked dose-related enlargement of the thyroid showing histological colloid struma. An increase in relative weight and moderate glycogenosis were detected in liver, whereas no lesions occurred in testes. It was concluded that thyroid and liver are the main targets for zineb toxicity in the rabbit. Unlike the results from previous studies conducted on other food-producing species, repeated exposure of rabbits to zineb failed to cause testicular damage. This might be related to the inability of zineb to significantly accumulate in the testes.
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Zineb/toxicidad , Análisis de Varianza , Animales , Peso Corporal/efectos de los fármacos , Hígado/química , Hígado/efectos de los fármacos , Masculino , Conejos , Testículo/enzimología , Testosterona/sangre , Hormonas Tiroideas/sangre , Factores de Tiempo , Zineb/administración & dosificación , Zineb/análisisRESUMEN
A PUFA-deficient diet causes deficiency symptoms and alters the fatty acid pattern in liver microsomal lipids. However, CCl4 lethality and sleeping time remain unchanged while the hepatic level of cytochrome P450 is only slightly lowered by the dietary regimen. In accordance, the amplitude of double bond shifting in microsomal lipids is far from being depressed in animals deprived of the peroxidative substrate. In fact, the experimental treatment does not impair intestinal absorption, liver uptake and metabolism of CCl4 given orally. Finally, both in vitro and in vivo peroxidative challenge of arachidonic acid content in hepatic microsomes causes comparable alterations of this parameter, whatever the initial fatty acid pattern following the dietary regimen. These findings provide evidence excluding an influence of the fatty acid composition of the diet on the severity of damages due to halogen-alkane exposure.