RESUMEN
Interstitial lung disease is a well-recognised manifestation and a major cause of morbidity and mortality in patients with connective tissue diseases. Interstitial lung disease may arise in the context of an established connective tissue disease or be the initial manifestation of an otherwise occult autoimmune disorder. Early detection and characterisation are paramount for adequate patient management and require a multidisciplinary approach, in which imaging plays a vital role. Computed tomography is currently the imaging method of choice; however, other imaging techniques have recently been investigated, namely ultrasound, magnetic resonance imaging, and positron-emission tomography, with promising results. The aim of this review is to describe the imaging findings of connective tissue disease-related interstitial lung disease and explain the role of each imaging technique in diagnosis and disease characterisation.
Asunto(s)
Enfermedades del Tejido Conjuntivo/diagnóstico por imagen , Diagnóstico por Imagen/métodos , Enfermedades Pulmonares Intersticiales/diagnóstico por imagen , Imagen Multimodal/métodos , Enfermedades del Tejido Conjuntivo/complicaciones , Humanos , Pulmón/diagnóstico por imagen , Enfermedades Pulmonares Intersticiales/complicaciones , Imagen por Resonancia Magnética , Tomografía de Emisión de Positrones , Ultrasonografía/métodosRESUMEN
INTRODUCTION: Hydrocephaly is a disease that affects not only the dynamics of the cerebrospinal fluid, but also other structures of the central nervous system. Although shunt is effective in reducing ventriculomegaly, many neurological damages are not reversed with surgery. Several studies demonstrate that oxidative stress is involved in the genesis of hydrocephalus lesions. OBJECTIVE: Evaluate the neuroprotective response of quercetin in hydrocephalus. MATERIALS AND METHODS: Male newborns rats were used, which received the 15% kaolin injection in the cisterna magna for induction of hydrocephalus. They were divided into control group (C), untreated hydrocephalic (HN), shunted hydrocephalic (HD), hydrocephalic treated with distilled water (HA), hydrocephalic treated with distilled water and shunt (HDA), hydrocephalic treated with quercetin peritoneal (HQp), hydrocephalic treated with quercetin peritoneal and shunt (HDQp), hydrocephalic treated with quercetin by gavage (HQg), and hydrocephalus treated with quercetin by gavage and shunt (HDQg). RESULTS: Quercetin significantly improved the immunohistochemical markers, mainly caspase and GFAP. There were no significant changes in clinical/behavioral assessment. The use of isolated quercetin does not alter the volume and ventricular size, and the realization of ventriculo-subcutaneous shunt in newborn rats with hydrocephalus presents a high morbi-mortality. CONCLUSION: The use of quercetin shows laboratory improvement of the effects of glial lesion and corpus callosum fibers and is therefore not justified by the use of the routine substance as neuroprotective.
Asunto(s)
Encéfalo/efectos de los fármacos , Hidrocefalia/patología , Fármacos Neuroprotectores/farmacología , Quercetina/farmacología , Animales , Antioxidantes/farmacología , Encéfalo/patología , Modelos Animales de Enfermedad , Masculino , RatasRESUMEN
Previous in vivo work showed that resveratrol has beneficial effects in the AD pathology, resulting in increased expression of transthyretin (TTR). TTR binds Aß peptide avoiding its aggregation and toxicity, and is reduced in the CSF and plasma, in AD. Further, resveratrol binds TTR, stabilizing the native TTR tetrameric structure. To further explore the mechanism of neuroprotection conferred by TTR in AD, resveratrol was administrated, in the diet, to 5-8 months old AD transgenic female mice carrying just one copy of the mouse TTR gene, for two months. Effects in brain Aß burden were evaluated by immunohistochemistry, and in total brain Aß levels by ELISA, showing a striking decrease in both parameters in treated animals. In addition, total brain LRP1 protein levels were increased in treated animals, although its gene expression was unaltered. To further understand the mechanism(s) underlying such improvement in AD features, we measured TTR plasma levels showing that TTR increased in resveratrol-treated mice, whereas liver TTR gene transcription was not altered. These results strengthen the stability hypothesis, which postulates that TTR is unstable in AD leading to accelerated clearance and lower levels. Therefore, resveratrol which stabilizes the TTR tetramer results in TTR normalized clearance, thus increasing the protein plasma levels. In turn, stabilized TTR binds more strongly to Aß peptide, avoiding its aggregation. Our results represent a step forward to the understanding of the mechanism underlying TTR protection in AD and highlight the possibility of using TTR stabilization as a therapeutic target in AD.
RESUMEN
This study was carry out to evaluate mRNA expression of mitochondrial cytochrome c oxidase III in the Pectoralis superficialis muscle of 28-day-old quails fed diets containing 0, 8, and 12% glycerol. Total RNA was extracted (N = 10) and cDNA was amplified using specifics primers for qRT-PCR. Feed efficiency and feed intake were evaluated. COX III mRNA expression in breast muscle was higher in the group fed with 12% glycerol (0.863 AU); no differences were observed in the expression of this gene between the muscle of animals fed diets without glycerol (0.357 AU) and 8% glycerol (0.415 AU). Quails that showed greater COX III mRNA expression also showed the lowest feed efficiency. These results show that there is a difference in COX III mRNA expression in breast muscle of 28-day-old quail fed diets different concentrations of glycerol.
Asunto(s)
Complejo IV de Transporte de Electrones/biosíntesis , Glicerol/administración & dosificación , Músculo Esquelético/efectos de los fármacos , Codorniz/genética , Alimentación Animal , Animales , Dieta , Complejo IV de Transporte de Electrones/genética , Regulación de la Expresión Génica/efectos de los fármacos , Músculo Esquelético/crecimiento & desarrollo , Músculo Esquelético/metabolismo , Codorniz/metabolismo , ARN Mensajero/biosíntesis , ARN Mensajero/genéticaRESUMEN
The northern region of Brazil produces a large number of sheep, with Pará being the largest sheep breeding state in the region. In the Amazon region, livestock production is a challenge due to the high diversity of pathogens affecting humans and animals. Defensins are antimicrobial peptides acting as a first barrier against micro-organisms and present high variation in different organisms. The objective of this study was to detect polymorphisms in exon II in ß-defensin II in Amazon sheep. The gene was amplified by PCR from DNA extracted from 47 sheep blood samples from the Santa Inês breed. Products were sequenced, aligned and analyzed. Three single nucleotide polymorphism (SNP) positions were observed with transition substitutions (AâG) at positions 1643, 1659, and 1750. The 1643 and 1750 SNPs showed a low variability and significant deviations from Hardy-Weinberg equilibrium (HWE) (P < 0.05) meanwhile the SNP 1659 showed moderate absence of genetic variability and deviation from HWE (P > 0.05). Polymorphisms at 1643 and 1659 were predicted to modify amino acids in the peptide chain (isoleucine to valine and arginine to lysine, respectively) with no effects on protein function. Results from this study suggest that SNPs are important markers for ß-defensin II efficiency studies on the immune system of sheep in the Brazilian Amazon.
Asunto(s)
Polimorfismo de Nucleótido Simple/genética , beta-Defensinas/genética , Animales , Brasil , Femenino , Inmunidad Innata/genética , Inmunidad Innata/fisiología , Masculino , OvinosRESUMEN
Beef cattle production requires reproductive efficiency. However, measures of reproductive traits are not usually collected; consequently, correlated traits that could be used as indicators would be useful. We examined associations between measures of reproductive and productive efficiency that could be used as selection indicators. Data from 194 dams of the genetic groups Angus x Nelore, Caracu x Nelore, and Valdostana x Nelore collected over 4 years were used. The reproductive traits analyzed were days to heat (DH), calving interval (CI), days to calving (DC), and pregnancy rate (PR). The productive traits were dam weight (DW), body condition score (BCS), calf weight (CW), and weaning rate (WR). The effects on the model were: year, genetic group, reproductive status (RS), age, reproductive rest, and breed of bull (CW and WR). Multivariate analyses were performed, using the Bayesian approach via Gibbs sampling. We conclude that the reproductive measures are ineffective as selection indicators, whereas using dam weight may be a good alternative.
Asunto(s)
Estudios de Asociación Genética , Carne Roja , Reproducción/genética , Animales , Teorema de Bayes , Peso al Nacer/genética , Peso Corporal , Cruzamiento , Bovinos , Cruzamientos Genéticos , Femenino , Genotipo , Masculino , EmbarazoRESUMEN
We evaluated messenger RNA (mRNA) expression of the growth-hormone (GHR) and insulin-like growth factor (IGF-1) genes in 28-day-old Japanese meat quails fed diets containing 0, 8, or 12% dietary glycerol in substitution of corn. Total RNA was extracted from the breast muscle and the DNA was amplified with specific primers using real-time PCR. Feed conversion ratio and feed intake were evaluated. The birds fed 8 and 12% glycerol presented higher IGF-1 mRNA expression [0.059 and 0.049 arbitrary units (AU), respectively] relative to those not fed with glycerol (0.029 AU), while 12% glycerol reduced GHR mRNA expression (0.022 AU). Dietary inclusion of 8% glycerol promoted similar performance results (feed conversion) as the diet with no glycerol. We conclude that inclusion of glycerol in the diet affects GHR and IGF-1 gene expression in Japanese meat quails. However, considering the performance results and the expression of the GHR and IGF-1 genes, 8% glycerol may be safely included in the diet of meat quails.
Asunto(s)
Expresión Génica , Glicerol/farmacología , Hormona del Crecimiento/metabolismo , Factor I del Crecimiento Similar a la Insulina/metabolismo , Carne/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Coturnix , Dieta/veterinaria , Relación Dosis-Respuesta a Droga , Factor I del Crecimiento Similar a la Insulina/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
Nanoparticles were prepared from a NdFeB-based alloy using the hydrogen decrepitation process together with high-energy ball milling and tested as heating agent for magnetic hyperthermia. In the milling time range evaluated (up to 10 h), the magnetic moment per mass at H = 1.59 MA m(-1) is superior than 70 A m(2) kg(-1); however, the intrinsic coercivity might be inferior than 20 kA m(-1). The material presents both ferromagnetic and superparamagnetic particles constituted by a mixture of phases due to the incomplete disproportionation reaction of Nd(2)Fe(14)BH(x) during milling. Solutions prepared with deionized water and magnetic particles exposed to an AC magnetic field (H(max) ~ 3.7 kA m(-1) and f = 228 kHz) exhibited 26 K ≤ ΔT(max) ≤ 44 K with a maximum estimated specific absorption rate (SAR) of 225 W kg(-1). For the pure magnetic material milled for the longest period of time (10 h), the SAR was estimated as ~2500 W kg(-1). In vitro tests indicated that the powders have acceptable cytotoxicity over a wide range of concentration (0.1-100 µg ml(-1)) due to the coating applied during milling.
Asunto(s)
Imanes/química , Nanopartículas/química , Nanotecnología/métodos , Neodimio/química , Animales , Compuestos de Boro/química , Línea Celular , Supervivencia Celular/efectos de los fármacos , Hipertermia Inducida/instrumentación , Compuestos de Hierro/química , Campos Magnéticos , Imanes/toxicidad , Ratones , Nanopartículas/toxicidad , Neodimio/toxicidad , Agua/químicaRESUMEN
Efficient conversion of food into body mass has been associated with altered gene expression of some proteins of the electron transport chain. We evaluated the effect of age on mRNA expression of uncoupling protein, adenine nucleotide translocase and cytochrome c oxidase complex III in quails. One-day-old broiler quails were sacrificed after 7, 14, 21, or 28 days. Six quails of each age were slaughtered by cervical dislocation. Total RNA was extracted from the breast muscle and reverse transcribed into cDNA. Real-time PCR analysis was performed using specific primers for the genes. As the quails aged, there was reduced expression of all three genes. The greatest reduction when comparing 7- and 28-day-old birds was observed in the uncoupling protein mRNA levels (67%), followed by adenine nucleotide translocase (56%) and cytochrome c oxidase complex III (30%). We conclude that expression of some mitochondrial genes of the electron transport chain changes with age in quails.
Asunto(s)
Envejecimiento/genética , Coturnix/genética , Regulación del Desarrollo de la Expresión Génica , Glándulas Mamarias Animales/metabolismo , Mitocondrias/genética , Proteínas Mitocondriales/genética , Músculo Esquelético/metabolismo , Alimentación Animal , Animales , Coturnix/crecimiento & desarrollo , Complejo IV de Transporte de Electrones/genética , Complejo IV de Transporte de Electrones/metabolismo , Femenino , Canales Iónicos/genética , Canales Iónicos/metabolismo , Glándulas Mamarias Animales/crecimiento & desarrollo , Translocasas Mitocondriales de ADP y ATP/genética , Translocasas Mitocondriales de ADP y ATP/metabolismo , Proteínas Mitocondriales/metabolismo , Músculo Esquelético/crecimiento & desarrollo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Proteína Desacopladora 1 , Aumento de Peso/genéticaRESUMEN
This work describes the new facility for applied nuclear physics at the University of Sao Paulo, mainly for irradiation of electronic devices. It is a setup composed of a quadrupole doublet for beam focusing/defocusing plus multiple scattering through gold foils to produce low intensity, large-area, and high-uniformity heavy-ion beams from 1H to 107Ag. Beam intensities can be easily adjusted from 102 particles cm2/s to hundreds of nA for an area as large as 2.0 cm2 and uniformity better than 90%. Its irradiation chamber has a high-precision motorized stage, and the system is controlled by a LabViewTM environment, allowing measurement automation. Design considerations and examples of use are presented.
RESUMEN
AIMS: To examine the virulence factors and the genetic relationship isolates of the serogroup O3 of Vibrio parahaemolyticus in outbreaks of diarrhoea in the northeast region of Brazil. METHODS AND RESULTS: Eighteen samples of the O3:K6 and O3:KUT serotypes of V. parahaemolyticus were analysed by multiplex polymerase chain reaction (m-PCR) for detection of the tl, tdh and trh genes, by random-amplified polymorphic DNA (RAPD) using two primers, and by amplification of the rDNA 16S-23S region. The gene tl was amplified in all the samples, tdh in 16 while trh in none; amplification of rDNA 16S-23S generated only one profile; each RAPD primer produced two amplification patterns allowing grouping two tdh(-) Kanagawa-negative isolates. CONCLUSIONS: V. parahaemolyticus with characteristics of the pandemic clone appears to be widely disseminated in the studied region. Because of the genetic uniformity of the isolates, elucidation of outbreaks or tracking the source of contamination by the present molecular techniques seems useless. SIGNIFICANCE AND IMPACT OF THE STUDY: Detection of V. parahaemolyticus with virulence potential of pandemic clone from two outbreaks and from several isolated gastroenteritis cases points out the need for inclusion of this micro-organism in the Brazilian routine monitoring of the diarrhoeas for elucidation of their aetiology.
Asunto(s)
Diarrea/microbiología , Gastroenteritis/microbiología , Vibriosis/microbiología , Vibrio parahaemolyticus/patogenicidad , Brasil , ADN Bacteriano/análisis , Brotes de Enfermedades , Humanos , Técnica del ADN Polimorfo Amplificado Aleatorio , Ribotipificación , Serotipificación , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/aislamiento & purificación , Virulencia/genéticaRESUMEN
We evaluated the effects of heat stress (HS) and methionine supplementation on biological markers of stress and expression of the genes for superoxide dismutase (SOD), thioredoxin (TRx), thioredoxin reductase 1 (TRxR1) and methionine sulfoxide reductase A (MsrA) in broilers aged 1 to 21 or 22 to 42 days. The broilers were divided into two treatments, one with the recommended level of methionine supplementation (MS, supplementation of dl-2-hydroxy-4-methylthiobutanoic acid (dl-HMTBA)) and one without methionine supplementation (MD). The animals were maintained at a temperature of thermal comfort or one of HS (38°C for 24 h). Mortality was only observed in 42-day-old broilers exposed to HS and fed the MD diet, and the rate was 5%. Starter period: we observed an interaction effect between diet and temperature on the gene expression of TRxR1 and MsrA, and expression of these genes was higher in the HS animals that received the MS diet than that in birds with the MD diet. Grower period: the expression of SOD, TRxR1 and MsrA genes, activities of aspartate aminotransferase (AST) and creatine kinase (CK) and content of creatinine were influenced by both study variables. In the HS animals, the expression of these genes, AST activity and creatinine content increased and CK activity decreased. In the animals on the MD diet, the expression of these genes and AST and creatinine values were higher and the CK activity was lower than those for the birds on the MS diet. Our results indicated that under HS conditions, the supplementation with dl-HMTBA could mitigate major damage caused by stress through the action on some genes related to TRx complex activity.
Asunto(s)
Antioxidantes/metabolismo , Pollos/fisiología , Suplementos Dietéticos , Respuesta al Choque Térmico , Metionina/metabolismo , Animales , Dieta/veterinaria , Calor , Masculino , Metionina/análogos & derivados , Tiorredoxinas/metabolismoRESUMEN
BACKGROUND: Aerophagia is a common childhood functional gastrointestinal disorder. We studied the association between adverse life events (ALEs), psychological maladjustment, somatization, and aerophagia (AP) in adolescents. We also assessed the impact of AP on their health-related quality of life (HRQoL). METHODS: A cross-sectional survey was conducted on 2500 subjects of 13-18 years in 8 randomly selected schools in Sri Lanka. Translated, validated, and self-administered questionnaires were used to collect data. Aerophagia was diagnosed using Rome III criteria. KEY RESULTS: A total of 2453 questionnaires were analyzed (males 1200 [48.9%], mean age 14.8 years, SD 1.6 years). Of them, 371 adolescents had AP (15.1%). Aerophagia was associated with exposure to physical abuse (20.4% vs. 12.7% in controls, P < .0001), emotional abuse (20.3% vs. 8.2% in controls, P < .0001), and other ALEs (22% vs. 10.2% in controls, P < .001). One hundred and ninety (51.2%) adolescents with AP and 775 (37.2%) controls had a personality score above the international cutoff value of 105, indicating psychological maladjustment (odds ratio 1.77, 95% confidence interval 1.42-2.21, P < .0001). Those with AP had higher somatization (16.4 vs. 8.9) and lower overall HRQoL scores (77.0 vs. 85.1, P < .0001). HRQoL scores of adolescents with AP were lower in all domains, namely, physical (80.6 vs. 86.9), emotional (69.1 vs. 80.3), social (83.8 vs. 90.5), and school (72.6 vs. 82.5) functioning (P < .0001). CONCLUSIONS AND INFERENCES: Aerophagia was associated with exposure to ALEs and psychological maladjustment. Affected teenagers suffer from more somatic symptoms and has a poor HRQoL.
Asunto(s)
Experiencias Adversas de la Infancia/estadística & datos numéricos , Aerofagia/psicología , Adolescente , Aerofagia/complicaciones , Aerofagia/epidemiología , Estudios Transversales , Femenino , Humanos , Masculino , Personalidad , Inventario de Personalidad , Calidad de Vida , Trastornos Somatomorfos/complicaciones , Trastornos Somatomorfos/epidemiologíaRESUMEN
In patients with severe autonomic dysfunction, water ingestion elicits an acute pressor response. Hypertension may be associated with changes in cardiovascular autonomic modulation, but there is no information on the acute effects of water ingestion in patients with hypertension. In this study, we compared the effect of acute water ingestion on haemodynamic and autonomic responses of hypertensive and normotensive individuals. Eight patients with mild hypertension were compared to 10 normotensive individuals. After 30 min resting in the supine position all subjects ingested 500 ml of water. At baseline and after water ingestion, venous blood samples for plasma volume determination were collected, and electrocardiographic tracings, finger blood pressure, forearm blood flow and muscle sympathetic nerve activity (MSNA) were obtained. Water ingestion resulted in similar and minor reduction in plasma volume. Systolic and diastolic blood pressure increased in both hypertensive (mean+/-s.d.: 19/14+/-6/3 mm Hg) and normotensive subjects (17/14+/-6/3 mm Hg). There was an increase in forearm vascular resistance and in MSNA. Heart rate was reduced (hypertensive: 5+/-1 beats/min, normotensive: 5+/-6 beats/min) and the high-frequency component of heart rate and systolic blood pressure variability was increased. In hypertensive and normotensive individuals, acute water ingestion elicits a pressor response, an effect that is most likely determined by an increased vasoconstrictor sympathetic activity, and is counterbalanced by an increase in blood pressure and heart rate vagal modulation.
Asunto(s)
Presión Sanguínea/fisiología , Ingestión de Líquidos/fisiología , Hipertensión/fisiopatología , Adulto , Velocidad del Flujo Sanguíneo/fisiología , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Sistema Nervioso Simpático/fisiología , Resistencia Vascular/fisiologíaRESUMEN
The objective of this study was to evaluate the frequency of C242T polymorphism on the aromatase gene and the allelic and genotypic frequency of these variants in sheep belonging to four breed groups. Blood samples were collected from 187 animals of four breed groups: Dorper, Santa Inês, Texel and White Dorper, originated from herds in the region of Maringá/PR, Brazil. The genomic DNA was extracted using alkaline extraction, with subsequent amplification of the fragments via PCR with specific primer. The samples resulting from amplification were subjected to digestion process using the Dpn II restriction enzyme and to polyacrylamide gel electrophoresis 10.0% and stained with silver nitrate. Three distinct genotypes were observed: homozygous (CC), heterozygous (CT) and homozygous for no cut (TT). The resulting data were analyzed using the POPGENE software with 5% significance. Genotypic frequencies among the breed groups were: Texel (CC - 0.426; CT - 0.511; TT - 0.064), Dorper (CC - 0.073; CT - 0.732; TT - 0.439), White Dorper (CC - 0.021; CT - 0.255; TT - 0.723) and Santa Inês (CC - 0.115; CT - 0.462; TT - 0.423).
Asunto(s)
Aromatasa/genética , Frecuencia de los Genes , Polimorfismo Genético , Ovinos/genética , Animales , Aromatasa/metabolismo , Genotipo , Ovinos/metabolismoAsunto(s)
Adenocarcinoma/secundario , Histiocitosis de Células de Langerhans/cirugía , Neoplasias Pulmonares/patología , Trasplante de Pulmón/efectos adversos , Complicaciones Posoperatorias/patología , Adenocarcinoma/radioterapia , Adulto , Progresión de la Enfermedad , Resultado Fatal , Femenino , Fluorodesoxiglucosa F18/metabolismo , Humanos , Trasplante de Pulmón/métodos , Estadificación de Neoplasias , Cuidados Paliativos/métodos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Articulación Sacroiliaca/diagnóstico por imagen , Articulación Sacroiliaca/patologíaRESUMEN
4'-Hydroxy-7,8-[2-(2-hydroxyisopropyl)dihydrofuran]flavan and 4',7-dihydroxy-8-(3,3-dimethylallyl)flavan, together with 10 known plant constituents, were obtained from the trunk bark of Brosimum acutifolium. Their structures were elucidated by spectroscopic methods, including 2D NMR spectroscopic techniques.
Asunto(s)
Flavonoides/aislamiento & purificación , Plantas Medicinales/química , Árboles/química , Cromatografía en Capa Delgada , Flavonoides/química , Espectroscopía de Resonancia Magnética , Espectrofotometría InfrarrojaRESUMEN
Optical absorption and fluorescence spectroscopies were employed in the study of the interaction between synthetic L-dopa (dihydroxyphenylalanine) melanin and the cationic porphyrins tetrakis(4-N-methylpyridyl) porphyrin (TMPyP), tetrakis(4-N-benzylpyridyl)porphyrin (TBzPyP), zinc tetrakis(4-N-methylpyridyl)porphyrin (ZnTMPyP) and zinc tetrakis (4-N-benzylpyridyl)porphyrin (ZnTBzPyP). Optical absorption and fluorescence properties of the porphyrins were dependent on the symmetry of the central ring. No evidence was found for dimerization of the porphyrins in phosphate buffer, pH 7, in the concentration range between 4 x 10(-8) to 5 x 10(-5) M. Addition of L-dopa melanin red shifted the optical absorption spectra of porphyrins, concomitant to broadening and reduction in intensity of the bands. L-Dopa melanin also strongly quenched the fluorescence of the porphyrins. Time resolution of the fluorescence decay of porphyrins showed at least two lifetimes that were only slightly modified in the presence of melanin. The interaction between melanin and porphyrin resulted in the formation of non-fluorescent ground state complexes. It was found that there are two different classes of binding sites in melanin for complexation with cationic porphyrins and the values of dissociation constants are of the order of 10(-8) M. These values and the number of binding sites are dependent on the nature of the porphyrins. It was shown that the binding has electrostatic origin, but it is also affected by metal coordination and hydrophobic interaction.
Asunto(s)
Melaninas/química , Porfirinas/química , Cinética , Espectrometría de Fluorescencia/métodos , Espectrofotometría/métodos , Relación Estructura-ActividadRESUMEN
To attempt the rapid detection of Salmonella enterica, we have coupled a culture procedure with PCR amplification of the genus-specific invE/invA genes. The method was applied to different kinds of samples from the poultry industry and evaluated by using hydrolyzed feather meal, meat meal, litter and viscera, all experimentally inoculated with a known number of Salmonella followed by cultivation in selenite--cystine broth prior to the PCR reaction. The expected 457bp specific DNA fragment could be amplified from dilutions containing as few as 5.7CFU, indicating that the PCR technique can be successfully coupled with culture in an enrichment broth to distinguish Salmonella species from other enteric bacteria present in samples from the poultry industry. Tetrathionate broth proved to be a much better enrichment media compared to selenite-cystine when the presence of Salmonella was evaluated by PCR in 1-day-old chicks experimentally infected with known numbers of Salmonella. Samples included cecal tonsils and viscera, collected at 48h and 7 days postinfection. The PCR technique was more sensitive in detecting infected animals than the standard microbiological procedure, which detected only 47% of all PCR positive samples.
Asunto(s)
Microbiología de Alimentos , Reacción en Cadena de la Polimerasa/métodos , Productos Avícolas/microbiología , Salmonella enterica/aislamiento & purificación , Animales , Pollos , Medios de Cultivo , ADN Bacteriano/químicaRESUMEN
This is the first report in literature showing the length of the seminiferous epithelium cycle in goats. In the present study, the duration of spermatogenesis was estimated using intratesticular injections of tritiated thymidine. Animals were castrated at 4 h, 7 days, and 11 days after injections. The duration of each spermatogenic cycle in goats is 10.6 +/- 0.5 days (SEM). Considering that the total duration of spermatogenesis takes about 4.5 cycles of seminiferous epithelium, spermatogenesis was estimated to last 47.7 days. The approximate primary spermatocytes life span is 14.1 days, while spermiogenesis in goats lasts 14.9 days. Staging in goats was based on the tubular morphology, where 8 stages of the cycle are yielded for all species. The relative stage frequencies in goats, based on 400 seminiferous tubule cross sections for each animal were as follows: stage 1: 15.8 +/- 1.0%; stage 2: 12.8 +/- 0.5%; stage 3: 20.5 +/- 0.9%; stage 4: 10.7 +/- 0.7%; stage 5: 11.6 +/- 0.6%; stage 6: 9.3 +/- 1.1%; stage 7: 7.6 +/- 0.4%; stage 8: 11.7 +/- 0.6%. The pre-meiotic, meiotic and post-meiotic phases' relative frequencies were 49.1%, 10.7% and 40.2%, respectively. The duration of spermatogenesis in goats is very similar to that found in rams.