PubMed Health⌕ Search

Biomedical subjects

C G Rousseaux

Publications and source records attributed to C G Rousseaux.

At least 37 records · Page 2Linked to original sources

The effects of feeding milk to diarrheic calves supplemented with oral electrolytes.

The effects of feeding different levels of milk to diarrheic calves (n = 19) supplemented with oral electrolytes were investigated. In the early stages of the disease the calves were fed either enough milk to maintain normal growth in a healthy calf, one half that volume or no milk. The three groups were further subdivided according to whether or not the electrolyte solution contained bicarbonate. A full milk ration allowed uninterrupted weight gains of 1% body weight/day (p = 0.003), but caused greater inappetence (p = 0.003 to 0.037) at the beginning of the trial than lower levels of milk intake. Electrolyte solutions with bicarbonate reduced growth rates in milk fed calves (p = 0.014). The density of fat stores increased with the level of milk feeding (p = 0.04 to 0.053). The mitotic index of the duodenal mucosa increased with milk feeding (p = 0.08), indicating a superior mucosal regeneration potential. Thymic atrophy was pronounced in those calves fed no milk (p = 0.001). It was concluded that the continued feeding of milk to diarrheic calves was beneficial. Electrolyte solutions containing bicarbonate should be avoided when milk is fed to diarrheic calves.

Animals↗

Whole blood platelet aggregation in dogs with liver disease.

Whole blood platelet aggregation was determined in response to collagen, arachidonic acid, and adenosine diphosphate in 20 dogs with liver disease and in 20 control dogs. Platelet aggregation in response to collagen and arachidonic acid was reduced in dogs with liver disease, compared with control dogs (P less than 0.05), whereas there was no significant difference in platelet response to adenosine diphosphate between the 2 groups of dogs. Adenosine diphosphate was found not to be a reliable aggregation agent for determination of whole blood platelet aggregation in dogs. Dogs whose platelets did not aggregate in response to collagen and/or arachidonic acid manifested bleeding tendencies that could be attributed to platelet dysfunction.

Adenosine Diphosphate↗

A survey of malformed aborted bovine fetuses, stillbirths and nonviable neonates for abnormal karyotypes.

Postmortem examinations were performed on 30 morphologically abnormal aborted bovine fetuses, stillbirths and nonviable neonates. Fibroblasts from the pericardium were cultured for chromosome analysis. Karyotypes were successfully completed on 18 animals, of which three were trisomic, one was mosaic monosomic and one was chimeric. All aneuploid calves had multisystemic anomalies. Using chromosomal banding techniques, the abnormal karyotypes were determined to be: 61,XY,+27; 61,XX,+21; 61,XY,+?; 59,XY,-?/60,XY; and 60,XX/60,XY. Bacterial contamination or nonviability of tissues prevented the growth of fibroblasts in culture and cytogenetic analysis of the other 12 animals. It was estimated that 2.0% of all late gestation abortuses and stillbirths may have chromosomal abnormalities characterized by aneuploidy. The findings of this study suggest chromosomal abnormalities characterized by aneuploidy are a significant cause of multisystemic anomalies in aborted bovine fetuses and nonviable neonates.

Abortion, Veterinary↗

Maternal toxicity, embryolethality and abnormal fetal development in CD-1 mice following one oral dose of T-2 toxin.

An experiment was undertaken to determine the teratogenic effect of oral administration of T-2 toxin, a trichothecene mycotoxin. Firstly, a dose response study using 0, 0.5, 1.0, 2.0, 3.0, 3.5 and 4.0 mg/kg T-2 toxin in propylene glycol, on day 9 of pregnancy, was undertaken. Maternal deaths and toxicity was noted in the 4.0 and 3.5 mg/kg groups post-toxin administration. These groups gained less weight throughout gestation than the rest of the groups, because no fetuses were found in the 4.0 mg/kg group and the 3.5 mg/kg group had significantly fewer fetuses than the remaining groups. The total fetal weight was similar among all groups with fetuses, and normal sex ratio of offspring was seen. More major and minor defects were seen in the 3.0 mg/kg T-2 toxin treated group than any other group. Secondly, a day response trial using a single dose of 3.0 mg/kg T-2 toxin given on either days 6, 7, 8, 10, 11 or 12 of gestation was undertaken. Maternal mortality, with placental hemorrhage, was observed. Fetal loss was greater in the T-2 toxin treated groups than in the starved controls. The greatest number of dead term fetuses was seen in mice treated on day 9 of gestation. Normal sex ratios were present in the offspring. Major skeletal defects were more numerous in mice treated on day 7 of gestation, whereas minor defects, retardations and variants were more common in mice treated on day 8. It was concluded that a single oral dose of T-2 toxin in propylene glycol is primarily maternotoxic and embryolethal, and that defective development was possibly secondary to maternal toxicity.

Animals↗

Effects of low-level long-term oral exposure to T-2 toxin in CD-1 mice.

In a 16-month feeding study male and female CD-1 mice received semi-synthetic diets containing 0, 1.5 or 3.0 ppm T-2 toxin. Feed consumption, body-weight gains, clinical findings (including haematological examinations at 16 months) and the development of external lesions were recorded. At 3, 6, 12 and 16 months, animals were killed for assessment of their immune function. Disease-related deaths did not differ among groups. Histological examination of all organs revealed statistically significant differences from controls in the incidence of pulmonary adenomas and hepatic adenomas in the 3.0-ppm group. Other treatment-related findings were an increased prevalence of epithelial hyperplasia in the forestomach of animals treated with T-2 toxin, and increased heart weights in treated male mice. T-lymphocyte-dependent humoral immunity tests did not reveal treatment effects and haematology revealed no particular trends. It is concluded that chronic feeding of T-2 toxin at low levels is not immunosuppressive but has a carcinogenic or tumour-promoting effect in mice.

Animals↗

Multiple defects in an aborted bovine foetus associated with chromosomal trisomy.

An aborted full-term bovine foetus bad multisystemic anomalies that included a heart defect, cleft palate, pulmonary hypoplasia and kyphoscoliosis. Karyotyping using pericardial sac fibroblast cells indicated that the foetal cells were trisomic. Trypsin-banding procedures and Giemsa staining revealed that the extra chromosome was presumptively Chromosome 27. This is the first report of chromosomal trisomy 27 in an abnormal bovine foetus, and highlights the significance of chromosomal aberrations as a cause of multi-systemic foetal anomalies.

Journal Article↗

Protection of newborn calves against fatal multisystemic infectious bovine rhinotracheitis by feeding colostrum from vaccinated cows.

To determine whether consumption of colostrum with high levels of serum neutralizing antibody to bovine herpesvirus 1 would protect neonatal calves from the frequently fatal multisystemic form of infectious bovine rhinotracheitis, Holstein calves were fed for 48 h after birth with either pooled colostrum from seropositive vaccinated cows or colostrum from seronegative unvaccinated cows. The serum neutralizing antibody achieved in the former calves was between 64 and 256 and the titer in the latter calves was below 8. At 48 h of age the calves were challenged by aerosolization with bovine herpesvirus 1. All five seronegative calves died or were euthanized in a moribund state between days 5 and 7 of the trial, whereas all five seropositive animals remained healthy throughout the study. Twice daily clinical examination revealed significantly lower scores in the seronegative group from 60 h postinfection. Relative lung weights were greater in the seronegative group, associated with a severe acute necrotizing bronchiolitis with fibrin exudation. The seronegative group of calves also demonstrated an acute necrotizing rumenitis, pharyngitis, glossitis, esophagitis, laryngitis and tracheitis. The seropositive animals had only small areas of subacute necrotizing fibrinopurulent rhinitis. Bovine herpesvirus 1 virus was isolated from all nasal passages of all calves but isolation of virus in the seronegative calves was made from the trachea (5/5), lung (4/5), bronchial lymph nodes (4/5), spleen (4/5), thymus (3/5), liver (2/5), rumen (2/5) and brain (1/5).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗

Embryotoxic effects of prenatal T-2 toxin exposure in mice.

Pregnant CD-1 mice were administered T-2 toxin by gastric intubation on day 11 of gestation at dosages of 0, 0.75 and 1.5 mg/kg. The T-lymphocyte dependent antibody response against sheep red blood cells which was evaluated in the offspring at six weeks of age was not affected by T-2 toxin exposure. Individual birth and weaning weights were not influenced by T-2 toxin, but the litter size was reduced in the high dose group, without affecting the number of implantation sites per dam. The number of female offspring produced by dams exposed to 1.5 mg/kg T-2 toxin was less compared to other treatment groups, suggesting that the female fetus was more susceptible to embryolethal effects of prenatal T-2 toxin exposure. These results suggest that prenatal T-2 toxin exposure is unlikely to be a significant health problem with respect to primary humoral immunity. At the dosages given, T-2 toxin produced substantial embryotoxicity without alteration in antibody production. The embryolethal effects are a primary limiting factor which may preclude the expression of any immunoteratological manifestations associated with humoral immunity under natural field conditions.

Animals↗

Reproductive and teratological effects of continuous low-level dietary T-2 toxin in female CD-1 mice for two generations.

A two-generation female reproduction and teratology study was undertaking using 0, 1.5 and 3.0 ppm of T-2 toxin in a semisynthetic diet. Conception rate was lowest at the first breeding and lowest in the control group at this time, but in later breedings the conception rates of each group were very similar. No significant differences were noted in litter size, death of fetuses, sex of fetuses and gestational length. Feed consumption was similar in all groups, as were the non-pregnant or pregnant female weight gains. Although the second-generation offspring grew faster than the first-generation offspring, and significantly lower body weights were seen in the 3.0 ppm T-2 toxin group at 2, 5 and 6 weeks of age, all offspring reached the normal weight for CD-1 mice at 6 weeks of age. Gross and histological evaluation of all animals at post-mortem examination did not reveal any significant results, nor were there significant differences in major and minor or retardation defects among the treatment groups. Relative spleen weights of the second-generation offspring were significantly higher in control females compared with the treated groups but treated males had significantly increased relative spleen weights compared with control males of this generation. It was concluded that no long-term reproductive and teratological effects of low-dose dietary T-2 toxin were found in this study.

Abnormalities, Drug-Induced↗

Acute Pinesol toxicity in a domestic cat.

The clinical, pathological and toxicological findings in a cat poisoned with Pinesol, a household cleaning agent, are reported. Clinically severe depression, with unresponsive pupils and extreme ataxia were observed prior to death. Pathologic changes consisted of severe acute centrilobular hepatic necrosis and renal cortical necrosis. Pinesol specific fatty acids and isopropanol were found using gas chromatographic analysis of kidney and fat. It was concluded that the cat died of Pinesol intoxication.

Animals↗

Intestinal strangulation associated with omphaloarteritis in a calf.

In a 1-month-old calf, intestinal strangulation developed when a jejunal segment wrapped around a bandlike adhesion between the greater omentum and an abscess of the left umbilical artery. Signs included abdominal distention, cessation of defecation, and purulent inflammation of the external umbilical stalk. Despite vigorous care, the calf died of shock 4 hours after admission.

Abscess↗

"Shaker" calf syndrome: a newly recognized inherited neurodegenerative disorder of horned Hereford calves.

The clinical and pathological features of a newly recognized, inherited neurodegenerative disorder in horned Hereford calves are described. The disorder is expressed in newborns by tremulous shaking of the head, body and tail, difficulty in rising, a wobbly spastic gait, and aphonia. Transient improvement is followed by deterioration and progressive spastic paraplegia. Generalized tremors can be induced easily by a variety of stimuli, and spinal reflexes may be exaggerated or depressed. The major pathological finding is an excessive accumulation of neurofilaments within neurons of the central, peripheral, and autonomic nervous systems. The involvement of multiple systems of neurons and the similarity with some forms of human motor neuron disease and spinocerebellar degeneration suggest that this unique bovine disease may serve as a suitable animal model for these human neurodegenerative disorders.

Animals↗

Automated differential staining for cartilage and bone in whole mount preparations of vertebrates.

An automated, rapid procedure for differential staining of cartilage and bone of vertebrates is described. The process involves rapid, complete staining of freshly skinned, eviscerated specimens after 30 sec immersion in a 70 C water bath, fixation in formol acetic alcohol and a rinse in 70% alcohol. Using an automatic tissue processor, the specimen is stained in alcian blue for 24 hr and macerated in 3% potassium hydroxide for 8 hr. Staining in alizarin red with maceration in 3% potassium hydroxide is completed manually. The specimens are cleared and preserved in glycerol. Good quality evenly stained specimens can be examined in less than three days and up to 600 fetuses can be processed in less than five days.

Animals↗

Fatal placental hemorrhage in pregnant CD-1 mice following one oral dose of T-2 toxin.

Forty-eight hours after oral administration of a single dose (3.0 mg/kg BW) of T-2 toxin to mice on days 7, 8, 10, 11 and 12 of pregnancy, 17% maternal mortality following vaginal hemorrhage was encountered. Necropsy examination of the dead females revealed that massive hemorrhages originating from the placental regions had occurred into the reproductive tract. This observation supports the studies in which hemorrhagic disease has been described as characteristic for intoxications with T-2 toxin. The results suggest that fatal hemorrhage during pregnancy can occur in hemochorial and hemoendotheliochorial placental mammals as a result of T-2 toxin administration.

Administration, Oral↗