Alkaloids in whole plant material: direct analysis by kinetic energy spectrometry

A new approach to mixture analysis has been applied to the direct detection of various alkaloids in plant materials. The method requires absolutely no sample treatment. Results are presented for cocaine, morphine, papaverine, coniine, and atropine. The signal-to-background characteristics are superior to those of conventional mass spectrometry. Sensitivity is sufficient to detect and identify between 1 and 10 nanograms of alkaloid.     

RESPONSES OF SHEEP TO ZYGADENUS GRAMINEUS, "DEATH CAMAS"

An extract of Zygadenus gramineus, "death camas," from which most of the resins had been removed was given intravenously to sheep prepared for recording blood-pressure and respiratory movements. Following the intravenous injection of this extract there occurred a respiratory inhibition which in the case of the injection of larger amounts of the extract was followed by asphyxia-like rises of blood-pressure. The graphic record of this asphyxial condition was practically duplicated by closing the tracheal cannula for a short time following the recovery of the animal from the effects of the plant extract. Although, from a field standpoint, no satisfactory antidote has been found, it has been demonstrated that caffein sodio-benzoate possesses marked powers of stimulation for the respiratory center affected by the depressive substances found in Zygadenus gramineus.     

Mechanisms controlling feed intake in ruminants: a review

The purpose of this paper is to review our understanding of the involvement of central and peripheral factors in the control of feed intake in ruminants. The regulation of body weight under various states of energy need depends on an animal's ability to control feed intake to meet these needs. In the central nervous system (CNS), the ventromedial and lateral hypothalamus appear to be the areas involved in satiety and hunger, respectively; other important areas are the paraventricular nucleus and rostral brain areas. Intracerebroventricular injection of neurotransmitters, alpha- and beta-adrenergic agonists, 5-hydroxytryptamine and gamma aminobutyric acid (GABA) agonists, has stimulated feeding in ruminants; intravenous administration of benzodiazepines stimulated feed intake in sheep and cattle, possibly by increasing GABA levels in the brain. Neuropeptides of the opioid and cholecystokinin families have reciprocal hunger-stimulating and satiety-eliciting effects when administered centrally in sheep. Further, concentrations of these neuropeptides in specific areas of the hypothalamus have been shown to change with the state of hunger-satiety of sheep. In the periphery, none of the hormones associated with the pituitary, adrenal gland, pancreas or gastrointestinal tract has been shown to have significant effects on the control of feed intake. In addition, the physical properties of the ingested feed in the gastrointestinal tract, while possibly influencing the rate or pattern of feeding, do not appear to be primary factors in the control of feed intake under many feeding conditions.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of neutrophils, tumor necrosis factor, and granulocyte macrophage/colony stimulating factor on Babesia bovis and Babesia bigemina in culture.

Bovine neutrophils, human recombinant tumor necrosis factor-alpha (TNF), and bovine recombinant granulocyte macrophage/colony stimulating factor (GM/CSF) were added to microaerophilic cultures of Babesia bovis and Babesia bigemina to determine if those substances could inhibit growth. Incorporation of [3H]hypoxanthine by the Babesia spp. was utilized as an indirect measure of parasite growth. When neutrophils were added to cultures of B. bovis and B. bigemina, the highest percentage inhibition of growth was attained. There was no significant enhancement of neutrophil killing when TNF or GM/CSF or both were added to either Babesia spp. Addition of TNF or GM/CSF or both substances (without neutrophils) resulted in an increase in growth of B. bovis and B. bigemina. For B. bovis, the group that contained neutrophils only and the group that contained neutrophils and TNF resulted in significantly higher growth inhibitions than the treatment group which contained neutrophils and GM/CSF or the group that contained neutrophils, TNF, and GM/CSF. No significant differences in inhibition were observed for the same treatment groups between B. bovis and B. bigemina.     

Equine Respiratory Disease on the Western Canadian Racetracks

The serological results from this study clearly show that both equine influenza and equine rhinopneumonitis viruses were present during spring and autumn epidemics of respiratory disease on Western Canadian racetracks. Approximately 11% of the horses showed significant convalescent titres to influenza while 9% showed significant convalescent titres for equine viral pneumonitis. It was noted in our study a positive vaccination history corresponded with a reduction in the severity of the respiratory infection.     

Outbreak of abdominal distension and obstipation in a C57BL/6J experimental autoimmune encephalomyelitis study

Seventy-four 9-week old female C57BL/6J mice housed in a conventional facility were manipulated to induce experimental autoimmune encephalomyelitis, among which 26 developed clinical signs including lethargy, absence of defecation, and abdominal distension. By gross necropsy examination, there was distension of the cecum and colon with fecal impaction. By histologic examination, there was severe ulcerative and proliferative typhlocolitis. Fecal ELISA confirmed the presence of toxins A and B of Clostridium difficile. Alteration in immune status of the immunocompetent mice, due to stress caused by experimental manipulation or autoimmune disease, may have led to intestinal dysbiosis, followed by opportunistic infections resulting in C. difficile-associated disease. This report brings to light the occurrence of the disease in immunocompetent laboratory mice during experimental manipulations associated with alteration in immune status, and it discusses potential hazards associated with conventional housing within a hospital-associated research institute.