RESUMEN
BACKGROUND: The most effective highly active antiretroviral therapy (HAART) to prevent mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1) in pregnancy and its efficacy during breast-feeding are unknown. METHODS: We randomly assigned 560 HIV-1-infected pregnant women (CD4+ count, > or = 200 cells per cubic millimeter) to receive coformulated abacavir, zidovudine, and lamivudine (the nucleoside reverse-transcriptase inhibitor [NRTI] group) or lopinavir-ritonavir plus zidovudine-lamivudine (the protease-inhibitor group) from 26 to 34 weeks' gestation through planned weaning by 6 months post partum. A total of 170 women with CD4+ counts of less than 200 cells per cubic millimeter received nevirapine plus zidovudine-lamivudine (the observational group). Infants received single-dose nevirapine and 4 weeks of zidovudine. RESULTS: The rate of virologic suppression to less than 400 copies per milliliter was high and did not differ significantly among the three groups at delivery (96% in the NRTI group, 93% in the protease-inhibitor group, and 94% in the observational group) or throughout the breast-feeding period (92% in the NRTI group, 93% in the protease-inhibitor group, and 95% in the observational group). By 6 months of age, 8 of 709 live-born infants (1.1%) were infected (95% confidence interval [CI], 0.5 to 2.2): 6 were infected in utero (4 in the NRTI group, 1 in the protease-inhibitor group, and 1 in the observational group), and 2 were infected during the breast-feeding period (in the NRTI group). Treatment-limiting adverse events occurred in 2% of women in the NRTI group, 2% of women in the protease-inhibitor group, and 11% of women in the observational group. CONCLUSIONS: All regimens of HAART from pregnancy through 6 months post partum resulted in high rates of virologic suppression, with an overall rate of mother-to-child transmission of 1.1%. (ClinicalTrials.gov number, NCT00270296.)
Asunto(s)
Terapia Antirretroviral Altamente Activa , Lactancia Materna , Infecciones por VIH/transmisión , VIH-1 , Transmisión Vertical de Enfermedad Infecciosa/prevención & control , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Adulto , Terapia Antirretroviral Altamente Activa/efectos adversos , Recuento de Linfocito CD4 , Femenino , Estudios de Seguimiento , Infecciones por VIH/tratamiento farmacológico , Inhibidores de la Proteasa del VIH/uso terapéutico , VIH-1/genética , VIH-1/aislamiento & purificación , Humanos , Lactante , Recién Nacido , Masculino , Neutropenia/inducido químicamente , Nevirapina/uso terapéutico , Cooperación del Paciente , Embarazo , ARN Viral/sangre , Factores de Riesgo , Carga Viral/efectos de los fármacos , Adulto Joven , Zidovudina/uso terapéuticoRESUMEN
BACKGROUND: With the technical advances of recent years, the number of operative manipulations in the abdominal cavity by laparoscopic surgery is now considered to be the same as that using classical open surgery. The question has been raised whether laparoscopic colorectal surgery with lymphadenectomy improves the recovery compared to open surgery. METHODS: We compared patients' physical activity for 7 days postoperatively as measured with an accelerometer between laparoscopic-assisted colorectal resection (LAC, n = 32) and classical open colorectal surgery (OC, n = 30). RESULTS: Physical activity expressed as cumulative acceleration was significantly higher in the LAC than in the OC group on each postoperative day. The recovery time, defined as the day on which the cumulative acceleration recovered to 90% of the preoperative level, was significantly shorter (p < 0.05) in the LAC (3.4 +/- 1.2 days) than in the OC group (6.8 +/- 1.7 days). CONCLUSION: Our results showed that the duration of convalescence with LAC was significantly shorter than that with the OC procedure. Laparoscopic colorectal surgery appears to allow an earlier recovery after the operation than the classical open procedure, and it is less invasive as assessed by convalescence.
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Aceleración , Neoplasias Colorrectales/cirugía , Laparoscopía/efectos adversos , Laparotomía/efectos adversos , Monitoreo Fisiológico/instrumentación , Actividad Motora , Recuperación de la Función , Anciano , Convalecencia , Defecación , Femenino , Humanos , Tiempo de Internación , Escisión del Ganglio Linfático/efectos adversos , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Dolor Postoperatorio/epidemiología , Periodo Posoperatorio , Resultado del Tratamiento , CaminataRESUMEN
BACKGROUND AND PURPOSE: Since the establishment of laparoscopic cholecystectomy (LC) for benign gallbladder lesions, the four-trocar method has been the standard procedure. However, the fourth trocar generally is used just for fundic retraction of the gallbladder. We have developed a three-trocar method for LC and performed it in 132 patients. PATIENTS AND METHODS: After the creation of the pneumoperitoneum, the first 10-mm trocar sheath was inserted in the subumbilicus for the endoscope, the second 5-mm trocar in the epigastric paramedian point for the working port, and the third 5-mm trocar in the subcostal area for grasping forceps. Monofilament nylon with a straight needle was inserted through the right 7th intercostal space in the anterior axillary line, and the seromuscular layer of the gallbladder fundus was punctured and retracted toward the anterior abdominal wall. After that, usual cholecystectomy was performed. RESULTS: Among the 132 patients who underwent the three-trocar method, 10 cases (8%) needed a fourth trocar. No patient was converted to open cholecystectomy. There were no significant differences in the operating time, the length of hospital stay after the operation, or the use of analgesics between the three-trocar and the four-trocar methods. No major complication was recognized. CONCLUSION: This method also has cosmetic advantages. Therefore, we believe this method might be recommended for LC.
Asunto(s)
Colecistectomía Laparoscópica/métodos , Enfermedades de la Vesícula Biliar/cirugía , Colecistectomía Laparoscópica/instrumentación , Estética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neumoperitoneo Artificial , Estadísticas no Paramétricas , Técnicas de Sutura , Resultado del TratamientoRESUMEN
The simplicity and good postoperative results of mesh plug repair for groin hernias have been reported in numerous articles. We have been performing this procedure in our department for more than 5 years, and the present study was conducted to reexamine its clinical outcome from our viewpoint. A total of 224 patients with a collective 244 groin hernias underwent mesh plug repair between March 1993 and August 1998. There were 155 (63.5%) indirect hernias, 79 (32.4%) direct hernias, 2 (0.8%) femoral hernias, and 8 (3.3%) compound hernias; 27 (11.1%) were recurrent hernias. Two plugs were inserted in all the compound hernias and in two of the direct hernias with a diffuse weak inguinal floor. The mean operating time was 32.2min. The complications that developed during this study were continuous pain in four patients, seroma in two, and hematoma in one. The rates of recurrence were 0% for indirect hernias and 12.7% for direct hernias. The patients in whom recurrence developed underwent mesh plug repair again and have had no further recurrence. Our experience showed mesh plug repair to be an excellent technique for indirect hernias or recurrent hernias after mesh repair, but it might be unsuitable for direct hernias with a diffuse bulging weakness in the floor of the inguinal canal.
Asunto(s)
Hernia Inguinal/cirugía , Mallas Quirúrgicas , Adulto , Anciano , Femenino , Estudios de Seguimiento , Hernia Inguinal/patología , Humanos , Masculino , Persona de Mediana Edad , Dolor , Complicaciones Posoperatorias , Recurrencia , Resultado del TratamientoRESUMEN
The present study is designed to clarify the mechanism by which the circadian pacemaker controls the locomotor activity of the hagfish and also to estimate the role of brain and spinal cord in the swimming behavior of the animal. We examined the effect of cutting the spinal cord at the 6 different positions on the circadian rhythm and the locomotor behavior of the animal. The most frontal cut was located between the brain and spinal cord, and the other 5 cuts were given to every 1/6 the length of the spinal cord. The relation between the locomotor activity and the cut position of spinal cord was summarized as follows. (1) When the ratio of frontal part before the cut was 0/6-1/6, the animal locomoted under initiative of caudal part, in random direction at the bottom and showed neither nocturnal rhythm in LD nor circadian rhythm in DD. (2) When the ratio of the frontal part before the cut was 4/6-5/6, the animal swam up to the surface under initiative of frontal part, and showed both nocturnal rhythm in LD and circadian rhythm in DD. (3) When the frontal ratio of spinal cord was 2/6 or 3/6, the animal showed both kinds of swimming behavior of (1) and (2). These results suggest that the descending system from the brain enable the hagfish to swim up to the surface and to express the rhythmicity of locomotor activity under control of the circadian pacemaker when at least frontal 2/6 of the spinal cord is connected to the brain by neuronal networks not by humoral factors.
RESUMEN
Laparoscopic cholecystectomy (LC) for gallstones has become a popular treatment modality, but LC for gallbladder cancer is not yet established and its prognosis is still unknown. We clinicopathologically studied unsuspected gallbladder cancer presenting at pathologic evaluation after LC. The entire cross section of gallbladders after 456 LCs was histologically examined. The presence of malignant lesions was confirmed in 13 (2.85%) of 456 cases. The preoperative diagnoses were gallstones in 5 patients, gallbladder polyps in 5, gallstones with gallbladder polyps in 2, and gallstones with adenomyomatosis in 1. The carcinoma had invaded the mucosa in 7, the proper muscle in 2, and the subserosa in 3; the serosa was exposed in 1. The tumor size ranged from 2 mm to the entire gallbladder. An additional resection was performed in 2 patients. During the mean follow-up period of 25.9 months, 1 patient died of recurrence at 8 months while 1 demonstrated recurrence at the port site 1 year after surgery. No other patients have had any recurrence to date. Since early gallbladder cancer removed laparoscopically can be expected to have a satisfactory outcome, diagnostic and therapeutic LC is recommended in cases where total biopsy is indicated. However, in every case, extreme caution needs to be exercised to prevent the dissemination and implantation of cancer cells at the port site.
Asunto(s)
Colecistectomía Laparoscópica , Colelitiasis/cirugía , Neoplasias de la Vesícula Biliar/diagnóstico , Anciano , Antígeno CA-19-9/sangre , Antígeno Carcinoembrionario/sangre , Colelitiasis/complicaciones , Femenino , Neoplasias de la Vesícula Biliar/sangre , Neoplasias de la Vesícula Biliar/complicaciones , Neoplasias de la Vesícula Biliar/patología , Humanos , Masculino , Persona de Mediana Edad , Invasividad NeoplásicaRESUMEN
Duplication of the cystic duct is a rare variation of the biliary system. It is important to pay attention to this variation to avoid intraoperative biliary system injury, especially during laparoscopic cholecystectomy. In a 66-year-old woman with gallstones, endoscopic retrograde cholangiopancreatography (ERCP) revealed no anomaly of the biliary system. At laparoscopic cholecystectomy, although intraoperative cholangiography demonstrated the second cystic duct, we misdiagnosed the duplication of cystic duct because preoperative ERCP had demonstrated normal anatomy. It was thought that the second cystic duct was dissected during the operation and the patient suffered from postoperative bile leakage. After reoperation, the patient recovered well. The diagnostic and therapeutic problems of such an anomaly are discussed below with the review of the literature.
Asunto(s)
Colecistectomía Laparoscópica/efectos adversos , Conducto Cístico/anomalías , Conducto Cístico/lesiones , Anciano , Colangiopancreatografia Retrógrada Endoscópica , Colelitiasis/cirugía , Femenino , Humanos , ReoperaciónAsunto(s)
Fístula Biliar , Fístula , Fístula Intestinal , Gastropatías , Fístula Biliar/diagnóstico , Fístula Biliar/etiología , Diagnóstico Diferencial , Fístula/diagnóstico , Fístula/etiología , Humanos , Fístula Intestinal/diagnóstico , Fístula Intestinal/etiología , Pronóstico , Gastropatías/diagnóstico , Gastropatías/etiologíaRESUMEN
Polypoid lesions of the gallbladder taken from 103 patients were examined to correlate clinical indicators with pathological characteristics. By ultrasonographic examination, no carcinoma was found in polypoid lesions with a diameter less than 1 cm. However, the incidence of carcinoma in those with diameters greater than 1 cm was 23%, a lower rate than expected from previous pathological studies. Comparison of ultrasonographic and actual measurements suggested that the size of cholesterol polyps tended to be overestimated by ultrasonography, suggesting that the apparent risk of cancer was decreased by cholesterol polyps. Laparoscopic cholecystectomy was performed in 30 patients with polyps. No complications were encountered, and operative time was significantly shorter (p < 0.01) than in the 116 laparoscopic cholecystectomies for cholelithiasis. This study demonstrated the difficulty in distinguishing large benign polyps from carcinoma by ultrasonography. To complete the diagnosis with less invasive intervention, we propose the use of laparoscopic cholecystectomy for patients with polypoid lesions larger than 1 cm by ultrasonographic estimation.
Asunto(s)
Adenocarcinoma/patología , Pólipos Adenomatosos/patología , Adenomioma/patología , Colecistectomía Laparoscópica , Neoplasias de la Vesícula Biliar/patología , Vesícula Biliar/patología , Pólipos/patología , Adenocarcinoma/diagnóstico por imagen , Adenocarcinoma/epidemiología , Adenocarcinoma/cirugía , Pólipos Adenomatosos/diagnóstico por imagen , Pólipos Adenomatosos/epidemiología , Pólipos Adenomatosos/cirugía , Adenomioma/diagnóstico por imagen , Adenomioma/epidemiología , Adenomioma/cirugía , Adulto , Biopsia/métodos , Femenino , Neoplasias de la Vesícula Biliar/diagnóstico por imagen , Neoplasias de la Vesícula Biliar/epidemiología , Neoplasias de la Vesícula Biliar/cirugía , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Pólipos/diagnóstico por imagen , Pólipos/epidemiología , Pólipos/cirugía , UltrasonografíaRESUMEN
By recording the locomotor activity rhythm of hagfish, Eptatretus burgeri, in which surgical lesions of the pretectal areas were made, we searched for the route of light information from the eyes to the circadian pacemaker, which is considered to be located in the preoptic nucleus. The entrainment of circadian activity rhythm to the light dark cycle, under 12 h light/12 h dark (12L:12D) was lost in animals whose pretectum was ablated with a pair of scissors and the animals then showed a free-running rhythm. Destruction of the pretectal areas with a high-frequency lesion generator also caused a free-running rhythm under 12L:12D. These findings indicate that retinal information may entrain the circadian rhythm via the pretectal areas, which have retinofugal connections.
Asunto(s)
Ritmo Circadiano/fisiología , Anguila Babosa/fisiología , Retina/fisiología , Animales , Encéfalo/fisiología , Encéfalo/cirugía , Lóbulo Óptico de Animales no Mamíferos/fisiología , Vías Visuales/fisiologíaRESUMEN
We investigated the inhibitory effects of a newly synthesized compound, sodium 1-[6-chloro-4-(3,4-methylenedioxybenzyl)-aminoquinazolin-2-y l]piperidine-4- carboxylate sesquihydrate (E4021), on five phosphodiesterase (PDE) isozymes isolated from porcine aortic smooth muscle. E4021 specifically inhibited type V phosphodiesterase (cyclic guanosine monophosphate [cGMP]-specific PDE) in a competitive manner. A comparison of the inhibitory profiles of zaprinast and E4021 indicated that E4021 is 100 times more potent and selective as a type V PDE inhibitor. E4021 caused a significant and sustained increase in the cGMP level in endothelium-denuded porcine coronary artery, but it had no effect on the cAMP level. This compound had a relaxant effect in porcine coronary artery precontracted by prostaglandin F2 alpha in the absence of endothelial cells and relaxed it more markedly in the presence of endothelial cells. E4021 had a synergistic effect with nitroglycerin in both the increase in cGMP level and the relaxant effect in isolated porcine coronary artery. E4021 caused a dose-dependent dilation of the large epicardial coronary artery, with a reduction in mean pulmonary arterial pressure, in conscious pigs instrumented chronically with a pair of piezoelectric crystals. These results suggest that the highly selective and potent inhibitor of type V phosphodiesterase E4021 causes relaxation of the large coronary artery via an increase in the cGMP level.
Asunto(s)
Vasos Coronarios/efectos de los fármacos , Inhibidores de Fosfodiesterasa/farmacología , Piperidinas/farmacología , Quinazolinas/farmacología , Vasodilatación/efectos de los fármacos , Animales , Vasos Coronarios/fisiología , GMP Cíclico/metabolismo , Relación Dosis-Respuesta a Droga , Técnicas In Vitro , Isoenzimas/antagonistas & inhibidores , Dinitrato de Isosorbide/farmacología , Masculino , Conejos , PorcinosAsunto(s)
Conducto Colédoco/patología , Enfermedades Pancreáticas/patología , Vena Porta/patología , Sarcoidosis/patología , Anciano , Constricción Patológica/etiología , Diagnóstico Diferencial , Humanos , Masculino , Enfermedades Pancreáticas/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Sarcoidosis/diagnósticoRESUMEN
A 52 year old man presented with primary thyroid plasmacytoma. The patient was initially followed up for thyroid dysfunction. The histological examination of the removed thyroid revealed a proliferation of mature and immature plasma cells indicative of plasmacytoma with Hashimoto's disease. After radiotherapy (40 Gy) to the neck following right hemi-thyroidectomy, the patient is currently alive and well 3 years after diagnosis without any evidence of tumor. The immunohistological examination of the removed thyroid showed monoclonality for immunoglobulin G-Kappa light chains. Sixty-six literature cases of primary thyroid plasmacytoma were reviewed and comparison of the clinical and histological characteristics between Japanese and Western cases noted. The incidence of the patients with antithyroid antibody was significantly lower (P < 0.01) in Western patients (42.9%) than in Japanese patients (87.5%). The higher incidence of thyroid dysfunction and Hashimoto's disease in Japan in comparison with Western nations was well reflected in the incidence of antithyroid antibody.
Asunto(s)
Plasmacitoma/patología , Neoplasias de la Tiroides/patología , Autoanticuerpos/sangre , Europa (Continente) , Femenino , Humanos , Inmunoglobulina G/sangre , Cadenas kappa de Inmunoglobulina/sangre , Inmunohistoquímica , Japón , Masculino , Persona de Mediana Edad , Plasmacitoma/inmunología , Plasmacitoma/fisiopatología , Plasmacitoma/terapia , Pruebas de Función de la Tiroides , Glándula Tiroides/inmunología , Neoplasias de la Tiroides/inmunología , Neoplasias de la Tiroides/fisiopatología , Neoplasias de la Tiroides/terapia , Tiroiditis Autoinmune/complicaciones , Estados UnidosRESUMEN
We synthesized various 4-[[3,4-(methylenedioxy)benzyl]amino]quinazolines substituted at the 5- to 8-positions and evaluated their inhibitory activities toward cyclic GMP phosphodiesterase (cGMP-PDE) from porcine aorta. Monosubstitution at the 6-position was essential for the inhibitory activity, and the preferred substituents were compact and hydrophobic: methoxy (3b, IC50 = 0.23 microM), methyl (3c, 0.10 microM), chloro (3d, 0.019 microM), thiomethyl (3f, 0.031 microM), and cyano (3p, 0.090 microM) groups. Compounds 3b-d,f,p lacked inhibitory activity toward other PDE isozymes (all IC50 values > 100 microM), and their relaxing activities in porcine coronary arteries were well correlated with the inhibitory activities toward cGMP-PDE (r = 0.88, p < 0.05). One of these compounds, 3b, elevated the intracellular cGMP level in isolated porcine coronary arteries without causing any change in the cAMP level. We consider that this series of compounds dilates coronary arteries via potent and specific inhibition of cGMP-PDE.
Asunto(s)
3',5'-GMP Cíclico Fosfodiesterasas/antagonistas & inhibidores , Quinazolinas/farmacología , Animales , Aorta/enzimología , Vasos Coronarios/efectos de los fármacos , Vasos Coronarios/enzimología , Vasos Coronarios/fisiología , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Técnicas In Vitro , Músculo Liso Vascular/citología , Músculo Liso Vascular/enzimología , Quinazolinas/síntesis química , Quinazolinas/química , Espectrometría de Fluorescencia , Relación Estructura-Actividad , Porcinos , Vasodilatación/efectos de los fármacosRESUMEN
By recording the locomotor activity rhythm of hagfish, Eptatretus burgeri, in which surgical lesions of the preoptic nucleus (PON) were made, we searched for the location of the circadian pacemaker in the hypothalamus. The characteristic rhythms were lost in animals lacking the anterior part of the hypothalamus, which includes the PON. Cuts in front of the PON did not affect the rhythm, but cuts behind the PON caused the animals to loose their rhythms. Destruction of the PON with a high-frequency lesion generator also caused loss of rhythms. These findings indicate that the pacemaker may be located in the PON, which has retinofugal connections.
Asunto(s)
Relojes Biológicos/fisiología , Ritmo Circadiano/fisiología , Anguila Babosa/fisiología , Área Preóptica/fisiología , Animales , Hipotálamo Anterior/anatomía & histología , Hipotálamo Anterior/fisiología , Actividad Motora/fisiología , Glándula Pineal/anatomía & histología , Glándula Pineal/fisiología , Área Preóptica/anatomía & histologíaRESUMEN
The effect of maternal exercise on the fetal and maternal heart rate was studied in 10 normal pregnant women in their third trimester. They participated in 15 minute graded treadmill exercise. Fetal heart rate (FHR), uterine contraction, maternal blood pressure, electrocardiogram, and oxygen consumption were monitored, before, during, and after exercise. FHR could be monitored in 7 women. Maternal maximal heart rate ranged from 143 to 168 bpm which approximated 61% to 84% training intensity. FHR showed a significant rise in 4 women during exercise. Of four cases which showed more than 70% training intensity, 3 demonstrated fetal tachycardia over 160 bpm and one demonstrated fetal bradycardia under 120 bpm. The baseline fetal heart rate remained from 120 bpm to 160 bpm in cases under 70% training intensity. There was no pathological deceleration and the variability was preserved in all cases. It is suggested that maternal exercise intensity should be less than 70% of the patient's maximal capacity, which approximates maternal heart rate of about 150 bpm.
Asunto(s)
Ejercicio Físico , Frecuencia Cardíaca Fetal , Embarazo/fisiología , Adulto , Presión Sanguínea , Femenino , Frecuencia Cardíaca , Humanos , Monitoreo Fisiológico , Consumo de Oxígeno , Contracción UterinaRESUMEN
It has traditionally been thought that diurnal rhythmicities cannot be entrained to follow adiurnal environmental cues that deviate greatly from a 24-hour periodicity. In this study, exposure of male rats pre- and postnatally to an adiurnal lighting schedule of 9 hours light: 9 hours dark resulted in the entertainment of certain hormonal rhythms (such as plasma corticosterone and plasma TSH) but not of others (such as pituitary TSH and plasma T3). Even though thyroid rhythms were influenced only partially by the shorter, 18-hour day, absolute levels of pituitary TSH and plasma T3 were significantly higher in experimental rats (9 hours light:9 hours dark) than controls (12 hours light:12 hours dark). Whole-body and kidney weights and tail length were also significantly increased in the 9 hours light:9 hours dark animals, suggesting a possible relationship of shorter day cycles to faster growth and higher thyroid hormone levels.
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Ritmo Circadiano , Corticosterona/sangre , Hormonas Tiroideas/sangre , Animales , Peso Corporal , Oscuridad , Luz , Masculino , Tamaño de los Órganos , Ratas , Tirotropina/sangre , Tiroxina/sangre , Triyodotironina/sangreRESUMEN
Levels of TSH, thyroxine (T4) and triiodothyronine (T3) were measured by radioimmunoassay in plasma (TSH, T4, T3) and pituitary (TSH) of 60-day old male Long-Evans rats. Definite diurnal rhythms were demonstrated in pituitary TSH, plasma TSH and T3 in intact rats, evidenced by the statistically significant differences between zenith and nadir for pituitary TSH, plasma TSH and T3. The zenith value of pituitary TSH and the nadir values of plasma TSH, T4 and T3 were observed at the same time (2400 h) as were the nadir value of pituitary TSH and the zenith values of plasma TSH, T4, and T3 (at 1200 h). Our results indicate that the rhythmicity of pituitary TSH content is a mirror image of that of plasma TSH. Adrenalectomy not only reduced plasma corticosterone levels to almost zero, but also decreased plasma T3 and T4 levels. In adrenalectomized rats, the absolute concentration of pituitary and plasma TSH increased at 1200 h and at 2400 h and, in both cases, the difference between values at 1200 h and at 2400 h persisted. The differences in plasma TSH, T3 and T4 between 1200 h and 2400 h were also observed in sham-adrenalectomized rats. These results suggest glucocorticoids do influence the pituitary-thyroid axis, but that the rhythmicity of the pituitary-thyroid axis does not seem to depend on the rhythmicity of glucocorticoid secretion.
Asunto(s)
Ritmo Circadiano , Hipófisis/fisiología , Glándula Tiroides/fisiología , Adrenalectomía , Animales , Masculino , Radioinmunoensayo , Ratas , Tirotropina/sangre , Tiroxina/sangre , Factores de Tiempo , Triyodotironina/sangreRESUMEN
Plasma levels of TSH, T4 and T3 in the rat show characteristic developmental patterns within the first postnatal month, with TSH reaching a peak on day 13, T4 on day 16 and T3 on day 20. In dark-reared rats, a significant reduction in plasma T3 associated with low plasma T4 as well as high plasma TSH suggest that light-deprivation from birth impairs and/or delays maturation of pituitary-thyroid axis.
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Oscuridad , Tirotropina/sangre , Tiroxina/sangre , Triyodotironina/sangre , Factores de Edad , Animales , Masculino , RatasRESUMEN
The os penis in mice and rats is composed of a proximal intramembranous and endochondral osseous element and a distal cartilaginous, ossifying element. Female mice, but not rats, have a small os clitoridis which corresponds to the intramembranous part of the proximal element of the os penis. In mice of either sex a dense mesenchymatous formation ventral to the urethra is the anlage for the bones of the external genitalia. In the early postnatal period the proximal part of the os penis develops as bone at the outer and as cartilage at the basal end of the anlage, while in females a minute focus of ossification differentiates into the small os clitoridis without passing through a cartilaginous phase. The distal element of the os penis is formed later than the proximal rod and grows at a slower rate. Neonatal treatment with an antiandrogen inhibits the increase in size and calcification of the os penis. Neonatal castration is an even more effective inhibitor. Neonatal treatment with testosterone or dihydrotestosterone, but not with oestradiol, stimulates the growth of the bony proximal os clitoridis, but induces only a rudimentary collagenous distal element. The differences between mice and rats in the response of the tissues of the clitoris to androgenic treatment are discussed, particularly as regards the differentiation of proximal and distal elements.