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Biomedical subjects

J Oliver

Publications and source records attributed to J Oliver.

At least 199 records · Page 11Linked to original sources
PubMed1980

Combined dexamethasone suppression and cosyntropin (synthetic ACTH) stimulation test in the dog: new approach to testing of adrenal gland function.

A combined dexamethasone suppression and cosyntropin (synthetic ACTH) stimulation test was developed in the dog so that information concerning pituitary gland (hypophysis) and adrenal gland competence could be provided in a single trial, during a short time span. Treatment of dogs with dexamethasone (0.1 mg/kg, IM) resulted in total suppression (below assay sensitivity or < 10 ng/ml) of plasma hydrocortisone (cortisol) at postinjection hour (PIH) 2 in 100% of the dogs, whereas suppression was inconsistent at PIH 1. Cosyntropin (0.5 U/kg, IV) administration to normal or dexamethasone-suppressed dogs increased plasma hydrocortisone concentration 3.5 to 4.5 times base-line values at PIH 1, which was the time of maximal effect. The combined test concept for adrenal gland function is valid, convenient (three sample collections; 3-hour period), and allows testing of adrenal gland response to dexamethasone suppression and ACTH stimulation in a single trial. The following test procedure for dogs is recommended: (i) collect base-line plasma sample (0900 hours) followed by injection of dexamethasone (0.1 mg/kg, IM); (ii) collect second plasma sample 2 hours after dexamethasone (to evaluate suppression of plasma hydrocortisone concentration) followed by the injection of cosyntropin (0.5 U/kg, IV); and (iii) collect a third plasma sample 1 hour later to evaluate plasma hydrocortisone concentration after cosyntropin stimulation.

Adrenal Glands↗
PubMed1980

Reduced tracheal mast cell numbers in adjuvant-sensitized rats associated with reduced pulmonary reactivity.

PVG/c inbred rats were sensitized by intra-peritoneal injection of DNP 19-ovalbumin with or without heat-killed Bordetella pertussis as adjuvant. The use of adjuvant was associated with a greater serum IgE, greater cutaneous immediate hypersensitivity, but no increase in immediate pulmonary reactivity to aerosol challenge. The number of mast cells in the trachea of adjuvant-sensitized rats was significantly reduced when compared with both unsensitized and allergen sensitized rats but this reduction in mast cell number did not occur in the skin. The reduction in tracheal and possibly other airway mast cells may explain the failure of the adjuvant sensitized rats to show increased pulmonary reactivity despite the increased serum IgE. The B. pertussis may have acted on the mediastinal lymph nodes, which drain both the peritoneal cavity and the lungs, to produce the observed reduction in tracheal mast cells.

Adjuvants, Immunologic↗
PubMed1980

Canine urethral pressure profile.

Urethral pressure profiles were recorded in seven normal female and six normal male dogs. Each dog was immobilized with xylazine, and a catheter (continuously infused with saline solution) was placed into the bladder through the urethra and withdrawn at a fixed rate. Pressure changes were recorded, and the resulting graphs provided values for pressures within the urethra. Nomenclature used to describe the urethral pressure profile was standardized according to the International Continence Society's recommenations. The maximum urethral closure pressures in the female dogs were between 13.0 and 46.0 mm of Hg (mean of 23.9 +/- SD 11.8 mm of Hg). There was a significant difference (P < 0.025) in the maximum urethral pressures of nulliparous female dogs less than 2 years of age when compared with those of older female dogs. The maximum urethral closure pressures in the male dogs were between 25.0 and 36.0 mm of Hg (mean of 28.3 +/- SD 4.0 mm of Hg).

Animals↗
PubMed1980

Gonadotropic activation induced by local photic stimulation of the lobus paraolfactorius in male quail.

Radioluminous material (RLM) was implanted in the paraolfactory area (a region which is linked to the gonadotropic infundibular complex by nervous pathways) of sexually quiescent quail exposed to short day lengths. Direct photic stimulation of the paraolfactory lobe (POL) resulted in significant testicular growth and increase in the plasma testosterone level. Red light (620 nm) emitting RLM was revealed to be somewhat more effective than green light (530 nm) emitting material. No difference appeared between the effect of local photostimulation of either the anterior or the posterior part of the POL. The gonadotropic response to paraolfactory lighting no longer occured after neural isolation of the infundibular complex.

Animals↗
PubMed1979

Stress and Protein Turnover in Lemna minor.

Transfer of fronds of Lemna minor L. to adverse growth conditions or stress situations causes a lowering of the growth rate and a loss of soluble protein per frond, the extent of the loss being dependent on the nature of the stress. The loss or protein is due to two factors: (a) a decrease in the rate constant of protein synthesis (ks); (b) an increase in the rate constant of protein degradation (kd). In plants adapted to the stresses, protein synthesis increases and the initially rapid rate of proteolysis is reduced. Addition of abscisic acid both lowers ks and increases kd, whereas benzyladenine seems to alleviate the effects of stress on protein content by decreasing kd rather than by altering ks. Based on the measurement of enzyme activities, stress-induced protein degradation appears to be a general phenomenon, affecting many soluble proteins. The adaptive significance of stress-induced proteolysis is discussed.

Journal Article↗
PubMed1979

Plasma testosterone and LH levels in male quail bearing hypothalamic lesions or radioluminous implants.

Radioluminous material (RLM) was implanted in either the infundibular complex or the preoptic area of sexually immature quail exposed to short days. Direct selective photic stimulation of the infundibular complex resulted in testicular growth (3,300 mg) and increase in levels of plasma testosterone (T, 23 ng/10 ml) and luteinizing hormone (LH, 4 ng/ml). Direct selective photic stimulation of the preoptic area did not induce any testis enlargement (84 mg) and plasma T and LH levels remained low (1.4 ng/10 ml and 0.9 ng/ml). However, preoptic as well as infundibular lesioning completely suppressed any gonadotropic and testicular responses to environmental photic stimulation. The respective and possibly differential roles played by these 2 structures in the photosexual reflex are discussed.

Animals↗
PubMed1979

Adrenal gland function in the horse: effects of cosyntropin (synthetic) and corticotropin (natural) stimulation.

The plasma concentration of hydrocortisone was determined in mares given either cosyntropin (100 IU, given IV) or corticotropin (200 IU, given IM). Plasma hydrocortisone concentrations of the mares treated with cosyntropin increased by 46%, 57% and 80% at 30, 60, and 120 minutes, respectively, when compared with base-line values; these values returned to base line at 240 minutes. In mares treated with corticotropin, mean plasma hydrocortisone concentrations increased by 42%, 143%, 101% and 155% at 30, 60, 120, and 240 minutes, respectively, when compared with base-line values. Differences in total leukocyte count, total eosinophil count, and plasma concentrations of electrolytes (calcium, sodium, magnesium, potassium) of cosyntropin- and corticotropin-treated mares, and these values in control animals were not significant. Results of the present study indicated that the horse responds to small dosages of cosyntropin (IV) in a prompt and reproducible manner as determined by plasma hydrocortisone values. Response to corticotropin was slow and less consistent. Thus, administration of cosyntropin to the horse, according to test results with paired samples collected (before administration and again at 2 hours after injection), was found to be a prompt and meaningful test of adrenal gland function.

Adrenal Glands↗
PubMed1979

Allergy in cystic fibrosis.

Forty-four patients with cystic fibrosis, sixty-seven parents, and thirty-nine controls were compared with regard to their immediate cutaneous hypersensitivity, total and specific serum IgE and serum IgG4 concentrations. The patients had increased prick test reactions and specific IgE to Aspergillus fumigatus. The development of reactions to A. fumigatus correlated with the severity of the disease. There were no other significant differences when serum total IgE, specific IgE and IgG4 concentrations or skin test reactivity were compared in the patients, parents and controls.

Adult↗
PubMed1979

Immunologic vasculitis in beige mice with deficiency of leukocytic neutral protease.

Immune complex vasculitis has been induced in normal mice and in mice with features of the Chediak-Higashi syndrome ("beige" mice). The accumulation of neutrophils in peritoneal exudates after the injection of C5a is not quantitatively depressed in beige as compared with normal mice. Immune complex-induced vasculitis in these two strains of mice is not quantitatively different, as assessed by vascular damage (vasopermeability changes and histologic criteria). Measurements of leukocyte enzymes confirm the findings of Vassalli et al. that leukocytes of beige mice lack neutral protease activity. The data suggest that the neutral protease of murine leukocytes does not account for the vascular damage of immune complex vasculitis.

Animals↗
PubMed1978

[Role of the infundibular complex and its neural afferents in the photosexual reflex in the quail].

The photosexual reflex was suppressed in quail after bilateral preoptic lesions. However an anterior-lateral de-afferentation of the hypothalamus of previously preoptic-lesioned quail resulted in partial photo-induced testis growth. As a working hypothesis, it is suggested that the preoptic area may control some unknown extrahypothalamic influences in order to modulate the gonadotropin controlling function of the infundibular area.

Afferent Pathways↗
PubMed1978

Site of respiratory reaction in allergic rats challenged via the airways.

Rats systemically sensitized to DNP-ovalbumin show a characteristic respiratory response to antigen challenge delivered via the airway. The slowing of expiratory air flow which occurs on aerosol challenge still occurs when the antigen is injected via a tracheostomy but not when it is delivered solely to the upper airways. Disodium cromoglycate administered via the tracheostomy 1 min before intratracheal antigen challenge reduces the respiratory response.

Administration, Intranasal↗