Physiological and metabolic responses in newborn piglets associated with the birth order.

The objective of this study was to evaluate the effect of birth order on the physiological and metabolic responses of the newborn piglet the first hours after birth. A total of 281 randomly selected newborn piglets were included, classified according to birth order in 12 groups (L1-L12). The expulsion interval, neonatal vitality, latency in connecting to the maternal teat and physiological profile were recorded for each piglet. The number of piglets born alive and dead was also recorded. The blood gases, electrolytes and glucose levels of the neonates were obtained by means of an automatic blood gas and electrolyte analyzer. Groups L1, L2, L11, and L12 had the least score on the vitality scale, the longest expulsion intervals, and longest latency to connect with the maternal teat, as well as greater physiological alterations (hyperglycemia, hyperlactatemia and hypercapnia) compared to groups L4 to L9. Likewise, type-II stillbirths only occurred in the first and last quarter of the birth order of the litter. In conclusion, piglets born in the first and last quarter of the birth order of the litter had a greater risk of having physiological and behavioral alterations during farrowing.

Evaluation of the protective effect of thiamine pyrophosphate based on the biochemical analysis of rabbit foetuses at 30 days of gestation.

This study evaluated the effects of thiamine pyrophosphate (PPT) on the biochemical profiles of full-term rabbit foetuses that were subjected to experimental ischemia followed by 24h reperfusion. A total of 16 gestating rabbit dams were divided into two groups, one of which was treated by administering PPT and subjected to a process ischemia. During this interval, fetal blood samples were drawn from each dam (in the ischemia group) at 0, 15 and 45min. Ischemia for 15 and 45min was not associated with changes in lactate levels of the Ischemia group foetuses. However, in the foetuses in the reperfusion groups without PPT lactate levels were significantly higher after 15 and 45min of arterial occlusion compared to time zero. These results demonstrate that PTT alters some acute and some longer-term biochemical outcomes of uterine ischemia perhaps important in preserving energy metabolism under hypoxic conditions.

Seroprevalence and risk factors associated with bovine herpesvirus 1 and bovine viral diarrhea virus in North-Eastern Mexico.

Bovine herpesvirus 1 (BoHV-1) and bovine viral diarrhea virus (BVDV) are well known etiological agents of cattle that produce important economic losses due to reproductive failures and calf mortality, as well as enteric and respiratory disease. Tamaulipas is located northeast of Mexico, an important cattle production and the principal exporter of calf and heifer to the United States. The objectives of this study were to estimate the seroprevalence of BoHV-1 and of BVDV, and to determine the effects of risk factors on these infections. Blood samples of cattle from 57 farms from rural districts of Tamaulipas were collected. The samples were tested for antibodies against BoHV-1 and BVDV using commercial ELISA kits. Data on potential risk factors were obtained using a questionnaire administered to the farmer at the time the blood samples were taken. The seroprevalences for BoHV-1 and BVDV were 64.4% and 47.8%, respectively. In the logistic regression analysis, the significant risk factors were rural district, herd size and cattle introduced to the farm. This study confirms the high seroprevalence of BoHV-1 and BVDV in unvaccinated cattle in Tamaulipas, Mexico. The results of this study could be used for the development of BoHV-1 and BVDV prevention and control program in North-Eastern, Mexico.

Prevalencia y factores asociados a la urticaria crónica. Análisis de la rinitis alérgica y los síntomas relacionados con el asma como factores asociados a la urticaria crónica en un área urbana del noreste de México / Prevalence and factors associates to chronic urticaria. Analysis of the allergic rhinitis and symptoms related to asthma as a f actors associated to chronic urticaria in a urban area of northeastem of Mexico

Antecedentes: La urticaria crónica es una enfermedad de origen de conocido difícil de tratar. Objetivos: Determinar la prevalencia. factores asociados y grado de participación de la rinitis alérgica y de los síntomas relacionados con el asma en la presentación de la urticaria crónica. Material y métodos: Se distribuyó un cuestionario a 3.000 persona de ambos sexo de 20 a 50 años de edad elegidas al azar. La muestra se dividió en dos grupos. uno con enfermos y otro con anos. Es un estudio de casos y controle. retropectivo. abierto y transversal. Resultados: Se obtuvo información completa de 2.613 cuestionario con una frecuencia de respuetas del 87 .1 o/e. En esta población. 788 persona refirieron padecer o haber padecido urticaria alguna vez en u vida. La prevalencia de urticaria crónica fue del 3.4lk: entre lo afectados predominó el sexo femenino (67 ,8%: OR = 1,44. p = S ). en el 14,4% de los casos los síntoma persitían durante la noche y en el 18.9% lo exacerbaba el ejercicio físico. Lo posible de encadenantes regitracto fueron lo alimentos ( 10% p = S) y lo medicamento (8.9%. p =NS) y el 81,1% de conocían la cau a. El 62.2lk de lo afectados tenían antecedente familiares de alergia (OR = 2.51 ). el 53,3% sufrían rinitis alérgica (OR = 1.81). el 32,2% sibilancia (OR = 2.10) y el 26,7% to seca (OR = 1.62). Conclusiones: Lo resultado demuestran que la prevalencia de urticaria crónica en rnás elevada que la publicada por otros autores. Adernás se obervó que lo antecedente familiares de alergia o personales de rinitis alérgica o de síntomas relacionados con el asma pueden tener relación con la presentación de urticaria crónica en el noreste de México (AU)

Objective: To determine the prevalence, posible asociate factors and participation leve] of the allergic rhinitis and symptoms related to asthma in the presentation of chronic urticaria. Methods: Written questionnaire were distributed to 3000 person elect at random. from the age of 20­50 years. women and man. We made up rwo groups from the total ampled. one with disease and the other with asymptomatic subjects. This is a retrospeciive, observational. open. and tran ver. al case­control study. Results:2613 quetionnaires had complete inforrnation. response rate 87.1 %. Ln this population. 788 reported experiencing or having experienced urticaria at sorne time during their life. urticaria chronic prevalence was 3.­t9'c. fernales sex were more affected (67.8. OR=l.­1­.+, p=NS). in l­1­.­l­9'c symptom. cominue at night and 18.9% worsening with exercise. Potencial cause that we found were foods ( 10% p= S). and drugs (8.99'c. p= ).81.1 o/e unknown cause. Person. that had urticaria chronic. Had relative with allergy (62.2%. 0R=2.5 I ). and additionally suffered from allergic rhinitis (53.3%. OR= 1.81 ). wheezing (32.29'c. 0R=2. I O). and dry cough (26.7%. OR= 1.62). Conclusions: The prevalence of the urticaria chronic documented. i greater than the other autors repon . And the familiar history of allergy. allergic rhinitis and asthma­related symptoms antecedent may have connection on the chronic urticaria in the nort­heastern of México (AU)

Ultrastructural changes in the lungs of neonatal rats intratracheally inoculated with meconium.

Meconium aspiration syndrome has been for many years an important cause of neonatal respiratory distress in newborn babies and sporadically reported in animals. This investigation was designed to study the ultrastructural and morphometric changes in the lungs of neonatal rats following the intratracheal inoculation of meconium. Seven-day-old Fischer-344 rats (n = 24) were randomly allocated in two groups. One group was intratracheally inoculated with saline solution and the second group received homologous meconium. Neonates were euthanatized at 1, 3 and 7 postinoculation days (PID) and lungs were examined by light and electron microscopy. Saline solution did not induce any ultrastructural changes in the lung. In contrast, meconium induced deciliation, recruitment of neutrophils and pulmonary alveolar macrophages to the bronchoalveolar space, intravascular sequestration of neutrophils and aggregation of platelets at PID 1 and 3. Other ultrastructural changes at PID 1 and 3 included interstitial edema and escape of red cells and fibrin into the alveolar space and interstitium. Interstitial edema and sequestration of neutrophils were responsible for the significant increase in thickness of alveolar septa. At PID 7 there was hyperplasia and enlargement of type II pneumocytes as well as interstitial proliferation of mesenchymal cells with intra-alveolar fibrosis. It was concluded that intratracheal inoculation of meconium in neonatal rats induces acute ultrastructural changes followed by a reparative response.

Microscopic changes induced by the intratracheal inoculation of amniotic fluid and meconium in the lung of neonatal rats.

Meconium aspiration syndrome is a major contributor to neonatal respiratory distress in infants and it has been sporadically recognized in neonatal animals. This investigation was designed to study the short and long term effects of meconium and amniotic fluid in the lungs of neonatal rats. Seven-day-old rats (n = 123) divided in three groups were intratracheally inoculated with saline solution, amniotic fluid or meconium. Rats were euthanatized on 1, 3, 7, 14, 28, 56 and 112 postinoculation days (PID) and the lungs were examined by light microscopy. Saline solution did not induce any change while amniotic fluid elicited only a mild foreign body response which disappeared by PID 14. In contrast, meconium induced an exudative alveolitis characterized by recruitment of neutrophilsn in the bronchoalveolar spaces. Meconium also induced atelectasis, hyperinflation and thickening of alveolar septa all of which had disappeared by PID 14. Starting at PID 7, neutrophils were progressively replaced by macrophages, giant cells, and some fibroblasts. There were sporadic foci of mineralization starting at PID 14 and lasting up to PID 112. Some mineralized foci became lined with cuboidal epithelial cells at PID 28. Meconium was slowly degraded but still evident by PID 112. It was concluded that inoculation of meconium in neonatal rats induces acute microscopic changes typical of meconium aspiration syndrome. The long term lesions induced by meconium consisted of persistent multifocal histiocytic alveolitis and bronchiolitis reaction with occasional foci of calcification.

Cytologic and biochemical changes associated with inoculation of amniotic fluid and meconium into lungs of neonatal rats.

OBJECTIVE: To evaluate the effect of homologous amniotic fluid and meconium inoculated intratracheally into the lungs of neonatal rats. ANIMALS: 153 male 7-day-old Fischer-344 rats. PROCEDURE: Amniotic fluid was obtained by cesarean section from the uterus of pregnant rats and meconium was collected at the time of birth from the gastrointestinal tract of neonatal rats. Neonatal rats were randomly allocated into 5 treatment groups. Two groups received 0.05 ml of saline (0.9% NaCl) solution; the third and fourth groups received 0.05 ml of 50% or 100% amniotic fluid, respectively; the fifth group was inoculated with 0.05 ml of a 20% suspension of meconium. Six or 7 rat pups/group were euthanatized by exsanguination under halothane anesthesia at postinoculation days 1, 3, 7, and 14. The magnitude of injury and inflammatory response was determined by biochemical and cytologic analyses of bronchoalveolar lavage fluid. RESULTS: Inoculation with saline solution and amniotic fluid did not induce pulmonary injury or inflammatory response. Inoculation with meconium induced significant (P < 0.01) injury and inflammatory response, characterized by the release of cytosolic enzymes and recruitment of neutrophils in the lung. CONCLUSIONS: Saline solution is an innocuous vehicle that can be safely used in intratracheal inoculations in neonatal rats. Homologous amniotic fluid, despite containing keratin and epidermal cells, does not cause acute injury or inflammation in the lung. In contrast, meconium acts as a toxic substance injuring respiratory cells and causing a vigorous but transient leukocytic inflammatory reaction in the lungs.

Transoral intratracheal inoculation method for use with neonatal rats.

BACKGROUND AND PURPOSE: Studying the effects of toxic and infective compounds on the respiratory system requires a reliable method for delivering inoculum into the distal region of the lung. Although transoral intratracheal inoculation methods have been well documented for adult rats, to the authors' knowledge, a reliable method has not been validated for neonatal rats. The purpose of the study reported here was to develop a simple method for transoral inoculation in rat neonates. METHODS: Seven-day-old Fischer 344 rats were anesthetized with halothane, and a spinal needle was inserted in the tracheal lumen, by use of illumination and a modified otoscope. Meconium was injected into the lungs as a marker, and the neonates were kept under close observation. After euthanasia at 24 h, lungs were removed and fixed in formalin, and the microscopic distribution of the inoculum was assessed in the left, right cranial, middle, median, and caudal lung lobes. RESULTS: Microscopic examination of lungs indicated that intratracheal inoculation was achieved in 100% of neonatal lungs and the inoculum was consistently distributed in the alveoli of all pulmonary lobes. Important complications or mortality were not observed in the neonates. CONCLUSIONS: Intratracheal inoculation of neonatal rats is possible by use of a modified otoscope for transoral illumination. This technique is simple and reproducible and ensures, without complications, widespread distribution of inoculum in the lungs of neonatal rats.

Effect of emu oil on auricular inflammation induced with croton oil in mice.

OBJECTIVE: To determine the acute anti-inflammatory effects of topically applied emu oil. ANIMALS: 96 male CD-1 mice assigned randomly to 4 groups, each comprising 24 mice. PROCEDURE: To induce auricular inflammation, 50 microl of a solution comprising 10 microl of croton oil dissolved in 1 ml of acetone was applied to the inner surface of the left auricle (pinna). One hour later, 3 or 5 microl of emu oil (low- and high-dose groups, respectively) or 5 microl of porcine oil (oil-control) was applied to the left pinna. Control mice remained untreated. Six mice per group were euthanatized 3, 6, 12, and 24 hours after induction of inflammation. Specimens of auricular tissue (ear plugs) were obtained, using a 6-mm biopsy punch. Magnitude of swelling was calculated as the weight difference between left (inflamed) and right (noninflamed) ear plugs; degree of edema was determined as the difference between wet and dry weights of the left ear plug. RESULTS: Magnitude of swelling was significantly reduced at 6 and 12 hours in mice treated with emu or porcine oil, compared with controls. The greatest reduction in swelling was detected in the high-dose emu group at 6 hours. Compared with controls, degree of edema was significantly reduced at 6 hours only in the high-dose group, whereas by 12 hours, all groups treated with oils had significantly less edema than controls. At 24 hours, magnitude of swelling and degree of edema did not differ among groups. CONCLUSION: Topically applied emu oil significantly reduced severity of acute auricular inflammation induced by croton oil in mice.

An outbreak of vampire bat-transmitted rabies in cattle in northeastern Mexico.

An outbreak of bovine rabies occurred on a ranch when cattle were bitten by vampire bats. Microscopic lesions showed a nonsuppurative encephalitis with intracytoplasmic inclusion bodies. Immunohistochemistry demonstrated viral antigen in the brain, and monoclonal antibodies identified a serotype 1 (vampire strain) of the rabies virus.

Taxonomical, clinical and pathological findings in moradilla (Lobelia-like) poisoning in sheep.

Each year during late winter and spring, grazing sheep and cattle in the State of Tamaulipas in northeastern Mexico develop toxicoses which have been empirically associated to consumption of a toxic plant locally known as moradilla. This investigation was undertaken to determine whether moradilla was a toxic plant not yet reported in Tamaulipas or was an unrecognized species of the Lobelaceae or Campanulaceae family. Taxonomic determination of moradilla plants collected from February to April showed that it was a species of Lobelia. Five alkaloids were identified by thin-layer chromatography in the mature stages of moradilla, while only 1 and 3 alkaloids were found in the growing and flowering stages of this plant, respectively. The alkaloids were not affected by making silage, drying in hay or freezing. Experimental intoxication of sheep with moradilla caused clinical signs and pathologic changes identical to those previously described for lobelia toxicosis. It was concluded that Lobelia berlandieri was the cause of moradilla toxicosis in grazing cattle and sheep of northeastern Mexico.

[Comparative techniques for the diagnosis of rabies and its incidence in Tamaulipas in 1987]. / Técnicas comparativas para el diagnóstico de rabia y su incidencia en Tamaulipas en 1987.

Rabies in suspect cases was diagnosed by immunofluorescence, histopathology and biological tests in samples from government health centers in Tamaulipas, Mexico during 1987. Comparative analysis between the diagnostic results and the epidemiological survey was performed. Brain samples of 278 suspect animals were studied; 45 cases were positive to rabies (16.1%). The centers providing high number of samples and positive cases correlate with counties of high human and canine population density, however, the percentage of positive cases versus samples sent does not correlate with the same counties, therefore making it possible to establish high risk areas. During spring, an increase of positive samples were received possibly associated with the canine breeding season. Urban rabies is a real problem in Tamaulipas, expressed by 97.7% of positive canine samples, 63.6% males and 36.3% females of an average age of fifteen months and were primarily of native breeds. Only 22% of positive cases had been previously vaccinated against rabies. A 56.3% incidence reduction versus the last four years was observed. It was concluded that a reduction of false positive results is possible when using the 3 diagnostic procedures described.

Tracheal versus pulmonary deposition and clearance of inhaled Pasteurella haemolytica or Staphylococcus aureus in mice.

The aim of this investigation was to do a comparative study on the deposition and clearance of inhaled bacteria between the lungs and tracheae of mice exposed to aerosols of bacteria. Two hundred and eighty-eight mice were divided into four groups (n = 72) and exposed to aerosols of Pasteurella haemolytica or Staphylococcus aureus in four replicates. The numbers of bacteria were determined in the trachea and lungs of mice sacrificed 0, 2, 4, 8, 12, 24, 48 and 72 hours postexposure. Results indicated that bacterial deposition was greater in lungs than in tracheae. No significant (p greater than 0.05) difference was observed between P. haemolytica and S. aureus clearance rates. Although bacteria were rapidly eliminated from the whole respiratory tract, bacterial clearance was significantly (p less than 0.002) faster in tracheae than lungs. A significant (p less than 0.05) replicate effect was also observed.

Pulmonary recruitment of neutrophils and bacterial clearance in mice inoculated with aerosols of Pasteurella haemolytica or Staphylococcus aureus.

Pulmonary alveolar macrophages are considered to be the main phagocytic cell of the pulmonary defense mechanism. However recent studies indicate that neutrophils may also participate in the defense against inhaled bacteria. The aim of this investigation was to study in mice the correlation between numbers of phagocytic cells in the bronchoalveolar space and the pulmonary clearance of bacteria. White mice were exposed to aerosols of Pasteurella haemolytica (n = 129) or Staphylococcus aureus (n = 129) in three different experimental replicates. Another group of mice (n = 22) was sham exposed to an aerosol of sterile phosphate buffered solution in a single replicate. Animals were sacrificed at various times postaerosolization. The numbers of neutrophils and alveolar macrophages in lung lavages and the pulmonary bacterial clearance rates were determined and statistically analysed. No significant differences (p greater than 0.05) were observed in the rates of pulmonary clearance between the two genera of bacteria, but P. haemolytica had a significant (p less than 0.05) replicate effect. The number of alveolar macrophages was not significantly affected by either bacteria or phosphate buffered solution. Exposure to P. haemolytica resulted in dramatic, significant (p less than 0.01) but transient increases in neutrophils in the bronchoalveolar space as well as a significant (p less than 0.01) increase in the weights of lung. The correlation between neutrophils and clearance was positive for P. haemolytica but negative for S. aureus. These results indicate that both species of bacteria are rapidly eliminated from the lung despite a rather different cellular response.