Hábitos de amamantamiento del ganado bovino Chinampo (Bos taurus) de México / Nursing habits of Chinampo cattle (Bos taurus) from México

Objetivo. Conocer los hábitos de amamantamiento de becerros Chinampos (Bos taurus) en diferentes etapas de su lactancia. Materiales y métodos. Se utilizaron 20 vacas con su cría. A partir de los 30 hasta los 180 días de la lactancia los animales fueron observados durante 24 horas continuas cada mes registrando la frecuencia con la que los becerros mamaron y la duración de cada amamantamiento. Resultados. Los becerros mamaron con mayor frecuencia entre las 06:00 y las 07:00 hr, se observaron otros picos a las 10:00 y a las 19:00 hr. La frecuencia promedio de amamantamiento en 24 horas fue de 4.9±0.21 utilizando un total de 66.9 ± 3.1 minutos. Los becerros de 180 días de edad mamaron menos veces comparados con los de edades inferiores a los 150 días; la duración del amamantamiento disminuyó a los 180 días de edad (p<0.05). Las hembras mamaron con más frecuencia que los machos (p<0.05) pero el tiempo que utilizaron para esta actividad fue similar entre sexos (p>0.05). Conclusiones. La frecuencia de amamantamientos es mayor durante las primeras horas de la mañana y al final de la tarde. Hasta los 5 meses de edad la frecuencia y el tiempo de amamantamiento no variaron pero se redujeron a los 180 días y las hembras mamaron con más periodicidad que los machos.

Tolerancia al calor y humedad atmosférica de diferentes grupos raciales de ganado bovino / Tolerance to heat and atmospheric humidity of different breeds groups of cattle

Objetivo. Comparar algunas respuestas fisiológicas al calor y humedad atmosférica entre bovinos Chinampos (Bos taurus; Ch), ½ Charolais ½ Brahman (CB), Holstein (H) y Jersey (J). Materiales y métodos. Se realizó un estudio en La Paz, México. Se utilizaron 12 vacas H, 10 J, 15 Ch y 8 CB. Durante el verano se midieron cada semana (a las 0600 y 1600 horas) la frecuencia respiratoria (FR) y temperatura rectal (TR). Se registraron las variables climáticas para calcular el índice de temperatura-humedad (ITH). Resultados. Durante todo el verano, la FR en los cuatro grupos estuvo por encima de los valores fisiológicos para el ganado bovino, siendo superior en H y J que en Ch y CB (p<0.01). En todos los grupos, la TR estuvo dentro de los límites fisiológicos de la especie estudiada. El grupo racial más afectado fue H (p<0.05). Cuando las constantes fisiológicas fueron analizadas dentro de cada una de tres categorías de ITH (<72, ≥72<78, y ≥78), las vacas H y J mostraron FR superior a las Ch y CB (p<0.01). La TR aumentó conforme se elevó el ITH siendo más marcado en J y H. El incremento de la FR entre la mañana y la tarde de cada día de medición fue mayor en H y J que en Ch y CB (p<0.05). La TR se incrementó más en H que en Ch (p<0.05). Conclusiones. Los grupos raciales más tolerantes al estrés por calor, determinado con base en FR y TR fueron Ch y CB.

The role of magnesium sulfate in prevention of seizures induced by pentylenetetrazole in rats / O papel do sulfato de magnésio na prevenção de crises induzidas por pentilenotetrazol em ratos

Magnesium sulfate (MgSO4) has been used to prevent seizures in eclampsia. This study examined the central effects of MgSO4 on different types of pentylenetetrazole (PTZ)-induced seizures. Male Wistar rats were submitted to intracerebroventricular (ICV) administration of MgSO4 at different doses followed by intraperitoneal administration of PTZ. The latency to the onset of the first seizure induced by PTZ was significantly increased by ICV administration of MgSO4 at a dose of 100 µg compared to the control treatment. In addition, the total period during which animals presented with seizures was significantly reduced at this dose of MgSO4. Furthermore, the latency to the onset of the first partial complex seizure was significantly increased by the lowest dose of MgSO4. However, a high dose of MgSO4 had no effect or even potentiated the effect of PTZ. These results suggest that, depending on the dose, MgSO4 may be important in prevention of epileptic seizures.

Sulfato de magnésio (MgSO4) é utilizado para prevenir crises epilépticas na eclampsia. Este estudo examina os efeitos do MgSO4 em diferentes tipos de crise induzidas por pentilenotetrazol (PTZ). Ratos Wistar foram submetidos à administração intracerebroventricular (ICV) de diferentes doses de MgSO4 seguida de administração intraperitoneal de PTZ. A latência para o início da primeira crise induzida por PTZ foi aumentada pela administração ICV de MgSO4 na dose de 100 µg quando comparada ao tratamento controle. Além disso, o período durante o qual os animais apresentaram crises foi reduzido com a mesma dose de MgSO4. A latência para o início da primeira crise parcial complexa também foi aumentada com a dose menor de MgSO4 (32 µg). No entanto, a maior dose (320 µg) de MgSO4 não foi efetiva ou até potencializou os efeitos do PTZ. Esses resultados sugerem que, dependendo da dose, o MgSO4 pode ser útil na prevenção de crises epilépticas.

Correlatos neuroendocrinológicos cognoscitivos de la anorexia nerviosa / Neuroendocrinologics cognitive correlates of anorexia nervous

Los trastornos del comportamiento alimentario son desórdenes cuyos costos económicos, emocionales y físicos son incal-culables tanto para el paciente como para su familia, otros significantes y los miembros del equipo de salud. La persona con anorexia nerviosa se caracteriza por presentar una negación a mantener el peso corporal igual o superior al esperado para la edad y la talla (reducción de un 15% o más del peso inicial), fuerte miedo a engordar, incluso estando en infra-peso, distorsión de la imagen corporal o la del peso, dependiendo la autoestima en exceso de su valoración y negando la repercusión del infrapeso en la salud y amenorrea, entre otros. Este artículo es el resultado de una revisión de la literatura reciente, se detiene fundamentalmente en la presentación de los correlatos que a nivel neuroendocrinológico y cognoscitivo se han identificado, llamando la atención en el papel de sustancias como la grhelina y la leptina, hasta las disfunciones cognoscitivas que acompañan el cuadro de anorexia nerviosa.

Alcohol dependence induced in rats by semivoluntary intermittent intake

The objetive of the present experiment was to assess ethyl alcohol (ETOH) dependence brought about by a semivoluntary intermittent intake regimen in rats. Male Wistar rats weighing 150-250 g at the onset of the experiment were assigned to the following groups: 0 percent ETOH (N = 11), 5 percent ETOH (N = 20), 20 percent ETOH (N = 20) and 40 percent ETOH (N = 18). ETOH solutions were offered at the end of the day and overnight from Monday to Friday, and throughout weekends, for 90 days. The concentration of the ETOH solutions was increased in a stepwise fashion allowing the rats to get used to the taste of alcohol. Reposition of pure water was permitted during 1-h water drinking periods in the morning. Daily volume intake (+ SEM) averaged 25.4 + 0.4 ml (0 percent ETOH), 23.8 + 0.6 ml (5 percent ETOH), 17.6 + 0.7 ml (20 percent ETOH) and 17.5 + 0.6 ml (40 percent ETOH). ETOH consumption differed significantly (P<0.05) among groups, averaging 4.4 + 0.2 g Kg(-1) day(-1) (5 percent ETOH), 10.3 + 0.3 g Kg(-1) day(-1) (20 percent ETOH) and 26 + 1.2 g kg(-1) day(-1) (40 percent ETOH). Furthermore, ETOH detection in plasma 10-12h after offering the solution indicated that its consumption in the 40 percent ETOH group was sufficient to override its metabolism. Overt signs of ETOH dependence, such as increased thirst, hyperactivity, puffing, hair ruffling and startle responsiveness as well as reduced drowsiness, were significantly increased in the 20 percent and 40 percent ETOH groups compared to the 0 percent and 5 percent groups. Accordingly, the model described here proved to be a useful tool for the evaluation of subtle or moderate behavioral and physical consequences of long-term ETOH intake.

Efeitos da administração crônica do álcool sobre os mecanismos neurais de regulação da pressão arterial / Effect of Chronic Administration of Alcohol and its Withdrawal on the Neural Mechanisms of Arterial Blood Pressure Regulation

PURPOSE: This study evaluated the effect of alcohol and its withdrawal on arterial baroreflex (BR) and cardiopulmonary reflex (CPR). METHODS: Male Wistar rats (150-250g) distributed in three groups (10-19 animals in each): ETOH 0, ETOH 5and ETOH 20, received alcohol solution at the end of the day and at night over the week, and all day and night at the weekends for a 90 day period. The BR function was assessed analyzing the bradycardic response to phenylephrine-induced vasoconstriction and tachycardic response to sodium nitroprusside-induced vasodilatation. The CPR was evaluated through the simultaneous bradycardic and hypotensive responses to 5-hydroxytryptamine (5-HT). The tests were performed in conscious animals in conditions of alcohol intake or 48h alcohol withdrawal. RESULTS: The nonwithdrawn animals of ETOH 5group showed significative decrease of mean arterial pressure compared to ETOH 0and an increase of heart rate compared to ETOH 0and 20groups. The sensitivity (gain) of baroreceptor reflex was significantly attenuated in ETOH 5withdrawn animals and in ETOH 5and 20animals nonwithdrawn. This was mainly due to the reduction of range of the baroreflex and changes in the bradycardia and tachycardia plateau. The nonwithdrawn ETOH 5group showed a higher effect of 5-HT (around 50) on the fall of diastolic arterial pressure. CONCLUSION: These results suggest that alcohol intake produced significant alterations in the neural mechanisms of cardiovascular regulation that could result in a dysfunction of blood pressure regulation.

Effects of haloperidol on behavioral responses induced by electrical stimulation of medial prefrontal cortex

The effects of haloperidol on circling and spying behaviors induced by electrical simulation of the medial prefrontal cortex (PFC) were evaluated. Male Wistar rats with an electrode implanted into the left medial PFC (B:2.5 mmA, 0.6 mm L and 2.7 mm V) were electrically stimulated in a sequence of ten 30-sec trains separeted by 30-sec intervals (60 Hz) in each session, and simultaneously observed in the open field. The animals with circling (CI) and spying (SP) behaviors were treated with intraperitoneal haloperidol (HAL ip, 5 mg/Kg, N=6) and saline (SAL ip, N=7) or intracortical HAL (ic, 5 mug, N=6) and SAL (ic, N=9), 20 min before the session of eletrical stimulation. HAL ic significantly decreased (p<0.05) CI (mean frequency+ SEM: 0.5 + 0.16) and monsignificantly decreased SP behavior (0.6 + 0.17) compared to SAL ic (CI:0.9 + 0.02, SP: 1+ 0). HAL ip fully abolished these behaviors P<0.05) (CI:0.02 + 0,SP: 0.01 + 0) compared to SAL ip (CI: 0.86 + 0.06, SP: 0.93 + 0.06. These results show that haloperidol, a dopaminergic antagonist and antipsychotic agent, interfered significantly with the expression of behaviors induced by electrical stimulation of the left medial PFC, suggesting that the induction of these behaviors may involve the dopaminergic neurotransmission.

Effect of age and magnesium administration on the performance of SHR in the elevated plus-maze

It is currently accepted that young spontaneously hypertensive rats (SHR) have lower pressure levels than adult SHR in which the hypertension is well established, reaching the highest plateau at about 24 weeks, and that treatment with magnesium initiated during intrauterine life postpones the onset of cardiovascular alterations in SHR to about 90 days. These animals also show many behavioral alterations. The anxiety of SHR was measured in the elevated plus-maze, considering the age of the animals and previous ingestion of food supplemented with 1 percent magnesium oxide. Both young (1.5-2 months) and adult (5-6 months) SHR showed higher mean) (+ or - SEM) percent of entries (48 + or - 3 and 51 + or - 3, respectvely) and a longer mean (+ or - SEM) percent of time spent (43 + or - 5 and 55 + or - 5, respectively) in the open arms when compared to the mean (+ or - SEM) percent of entries and time spent in the open arms of young (35 + or - 3 and 20 + or - 4, respectively) and adult (36 + or - 7 and 17 + or - 5, respectively) normotensive Wistar rats. Treatment with magnesium oxide did not alter the performance of SHR in the elevated plus-maze. SHR showed an anxiolytic-like behavior which was neither influenced by age nor by antihypertensive treatment

Effects of the antihypertensive drugs Ó-methyldopa and hydralazine on the performance of spontaneously hypertensive rats in the elevated plus-maze

The effects of antihypertensive drugs on the performance of spontaneously hypertensive rats (SHR) in the elevated plus-maze were determined. Male SHR (3 months old) were submitted to long-term treatment (15 days) with Ó-methyldopa (ÓMD, 5g/l, N = 10) and hydralazine (HYD, 100 mg/l, N = 10) given orally, diluted in water. After the drug treatment, the performance of the rats in the plus-maze was observed for 5 min in a single test and mean arterial pressure (MAP) and heart rate (HR) were then measured. The antihypertensive drugs reduced MAP significantly (mean ñ SEM:CON = 176.2 ñ 5.2, ÓMD = 157.8 ñ 4.6 and HYD = 150 ñ 4.4 mmHg) and only ÓMD increased HR significantly (mean ñ SEM:CON = 391.7 ñ 13.8, ÓMD = 453.3 ñ 14 and HYD = 368.8 ñ 18.9 bpm). The ÓMD group presented a lower total number of entries (mean ñ SEM:CON = 12.7 ñ 0.7, ÓMD = 8.7 ñ 0.9 and HYD = 12 ñ 0.9) and spent less time in the open arms than the CON (N = 10) and HYD groups (mean ñ SEM:CON = 0.69 ñ 0.04, ÓMD = 0.48 ñ 0.07 and HYD = 0.65 ñ 0.06 s). ÓMethyldopa acts centrally and hydralazine acts peripherally. The behavioral change of SHR treated with Ó-methyldopa suggests that hypertension seems to be related to central nervous dysfunctions that are affected by an antihypertensive drug with central noradrenergic action

Tratamiento de la tuberculosis pulmonar resistente mediante quimioterapia e inmunomoduladores. / Treatment of drug resistant pulmonary tuberculosis by chemotherapy and immunomodulators

Se trataron 16 casos de tuberculosis pulmonar avanzada y resistente a diversos regimenes terapeuticos mediante quimioterapia y drogas que modifican la respuesta inmune. En todos los enfermos se encontro inmunodepresion en la valoracion inicial.Los inmunomoduladores empleados fueron Corynebacterium parvum de la cepa N C T C 1038 y levamisole, los cuales se administraron de acuerdo a lo establecido por oros autores en la inmunomodulacion de neoplasias. Se obtuvo mejoria clinica e inmunologica desde los tres primeros meses de tratamiento, el descenso y la desaparicion de los bacilos entre los seis y nueve meses y se dieron por resueltos los casos entre ano y ano y medio de tratamiento.Practicamente no hubo modificacion del aspecto radiologico, ya que existia fibrosis intensa mucho tiempo antes de la iniciacion del empleo de esta modalidad

Sindrome de Guillain-Barre. Estudio clinico de 339 pacientes. / GuillainBarre's syndrome. Clinical study of 339 patients

Estudiamos las historias clinicas de 339 pacientes con diagnostico de sindrome de Guillain-Barre; hacemos especial enfasis en aquellos seguidos desde enero de 1970 a diciembre de 1978. Comentamos los aspectos epidemiologicos, la evolucion clinica, el prognostico, las secuelas y los tratamientos del sindrome.Algunas manifestaciones como la rapidez en la instauracion de los sintomas, el compromiso respiratorio y la alteracion del X par, son indices de mal prognostico. Un 24% de los pacientes quedan con secuelas, la mayoria de las veces no limitantes. La mortalidad en esta serie es del 11% y puede considerarse relativamente baja. Hasta el momento no se conoce medicacion capaz de modificar la evolucion de la enfermedad

Agenesia da valva pulmonar associada a comunicacao interventricular. / Pulmonary valve agenesia associated with interventricular communication

Os autores relatam um caso de agenesia da valva pulmonar, associada a comunicacao interventricular, em paciente de 57 anos de idade operado com sucesso. Discutem a precocidade do aparecimento dos sintomas, o alto indice de morbidade e mortalidade na primeira infancia, bem como as manobras semiologicas empregadas para o correto diagnostico da doenca. Abordam tambem a histopatologia e a embriogenese da malformacao, o quadro clinico, os metodos complementares de investigacao e o tratamento

Aire libre subdiafragmatico? Interposicion colonica hepatodiafragmatica?. / Subdiaphragmatic free air? Hepatodiaphragmatic interposition of colon

Se presenta el caso de un paciente masculino de 62 anos de edad, que ingreso al servicio de urgencias por presentar cuadro abdominal agudo de dos horas de evolucion. Al efectuarse una placa posteroanterior de torax se encontro una imagen sugestiva de aire libre subdiafragmatico. Dada la gran cantidad de aire y la separacion entre el higado y el diafragma, se repitieron los estudios radiograficos, demostrando que la imagen aerea obedecia a la interposicion de un segmento colonico entre el higado y el diafragma (Sindrome de Chilaiditi). En base al cuadro clinico y no al radiologico, se efectuo laparatomia exploradora de urgencia encontrando peritonitis biliar consecutiva a la perforacion de la vesicula biliar. Se efectua revision de las placas de torax cuando existe aire libre subdiafragmatico. En caso de duda las proyecciones laterales son de gran utilidad