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Biomedical subjects

J C Murphy

Publications and source records attributed to J C Murphy.

At least 91 records · Page 5Linked to original sources

Heterotopic bone formation following total hip arthroplasty in ankylosing spondylitis.

Heterotopic ossification is a well-recognized complication of total hip arthroplasty. In a retrospective survey of 98 total hip arthroplasties in ankylosing spondylitis performed between 1970 and 1977, 39.8% showed some evidences of heterotopic ossification. Restriction of hip movements was noted in only two. Heterotopic ossification occurred within one year and was higher (64.6%) in patients with bilateral hip replacements if there was evidence of heterotopic bone formation in one hip. The complications were relatively high in hips with previous operations (55%); trochanteric bursitis (50%); and trochanteric detachment (63.3%). No correlation was found between high erythrocyte sedimentation rate and the incidence or extent of heterotopic bone formation.

Blood Sedimentation↗

Effect of renal denervation on the antinatriuretic response to morphine administration in conscious rats.

The effect of surgical denervation on the antinatriuretic response to morphine was assessed in conscious rats prepared with arterial and venous catheters and bladder cannulas. In sham-operated animals, morphine sulfate (4 mg/kg i.v. plus 2 mg/kg X hr) caused a marked reduction in sodium excretion (650 +/- 218 vs. 2394 +/- 265 nEq/100 g X min in vehicle-treated animals; P less than .05). Although glomerular filtration rate was reduced, fractional excretion of sodium, expressed as a percentage of the filtered load, was also markedly decreased by morphine (0.62 +/- 0.18 vs. 1.51 +/- 0.15% in the vehicle group; P less than .05). The changes in sodium excretion were readily reversed by naloxone. In rats subjected to the renal denervation procedure, morphine had no effect on sodium excretion (1614 +/- 261 vs. 1926 +/- 520 nEq/100 g X min) or on fractional sodium excretion (1.92 +/- 0.50 vs. 1.41 +/- 0.37%). However, glomerular filtration rate was reduced by morphine as in the sham-denervated rats. Blood pressure and heart rate were not significantly affected by morphine in either group. The results suggest that morphine enhances renal tubular sodium reabsorption, at least in part, by a mechanism dependent on intact renal nerves. Because there was no evidence of generalized sympathetic activation (as judged by blood pressure and heart rate changes), the effect may be selective for the renal innervation.

Animals↗

Conversion of hip fusion to Charnley low-friction arthroplasty.

Spontaneous fusion of the hip following infection or surgical procedures can result in deformity that causes degenerative change in the associated joints. Loss of function can cause pain in adjacent joints. Conversion of hips fused in a deformed position to low-friction arthroplasty reduces shearing strain and improves walking function. Conversion of the fused hips constitutes a technically difficult procedure; adequate exposure with trochanteric osteotomy with the patient in the supine position is strongly advocated.

Adolescent↗

Campylobacter-like organisms isolated from gastric mucosa of ferrets.

Campylobacter-like organisms (CLO) were isolated from gastric lesions in 1 ferret and gastric mucosa of 2 healthy ferrets. The organism was not isolated from biopsies of gastric mucosa of 14 other healthy ferrets, 1 of which had small gastric lesions located at the pylorus. Lesions from which CLO were isolated were located in the antrum of 1 ferret and were classified as inflammation with repair. Affected gastric tissue was highly vascularized with fibrous connective tissue surrounding irregularly shaped glands. Necrosis and ulceration of adjacent mucosa also were observed. Using Warthin-Starry stain, Campylobacter-like organisms were seen on and in the glandular epithelium of the ferret with gastric lesions from which CLO were isolated.

Animal Diseases↗

Colonization of Syrian hamsters with streptomycin resistant Campylobacter jejuni.

A streptomycin resistant Campylobacter jejuni inoculated per os into two populations of Syrian hamsters (one endemically harboring C. jejuni, the other free of C. jejuni) established chronic colonization of the organism in both groups. Diet, steroid administration, age of hamsters or prior exposure to C. jejuni did not appreciably alter incidence of diarrhea or colonization of C. jejuni. The majority of hamsters sampled during the course of the experiment (1 to 22 weeks) shed streptomycin resistant C. jejuni in the feces. In four hamsters sampled at 14, 17, 19, and 22 weeks, post inoculation, streptomycin resistant C. jejuni were recovered in ileal, cecal, jejunal, duodenal and colonic contents (10(4) to 10(7) colony forming units/gram of intestinal content). The hamster appears to be a potentially useful model for the study of intestinal colonization of enteropathogenic C. jejuni. Hamsters shedding C. jejuni in their feces for extended periods of time should be considered a zoonotic threat to both pet owners and laboratory personnel.

Animals↗

Serum chemistry reference values in two strains of Syrian hamsters.

Blood samples were collected from 30 male and female hamsters (Mesocricetus auratus) from two sources. Serum was collected and analyzed for 17 biochemical values. The results were analyzed statistically and comparisons were made between males and females and between strains.

Animals↗

Nephrotic syndrome associated with renal amyloidosis in a colony of Syrian hamsters.

A 6% incidence of nephrotic syndrome was noted in a colony of 400 Syrian hamsters (Mesocricetus auratus) over a period of 2 years. Clinical findings consisted of severe ascites and anasarca, anorexia, cachexia, and papular dermatitis. Serum and urine chemical analysis revealed proteinuria and hypoalbuminemia in all animals tested; hypoproteinemia and high concentrations of serum cholesterol, triglycerides, and creatinine were detected in some of the affected hamsters. Demodex aurati was detected in skin scrapings from 4 of 8 hamsters. Necropsy findings included subcutaneous edema, ascites, and hydrothorax, as well as atrophic kidneys and testes. Extensive deposits of type AA amyloid were detected histologically in kidney, liver, spleen, and adrenal gland; smaller deposits were found in thyroid gland and intestine. Other histologic findings included periodontitis and hyalinization of the small arteries of the testes.

Amyloidosis↗

Natriuretic effect of naloxone in fasted, water-loaded rats.

The influence of naloxone (10 mg/kg i.p.) on water and electrolyte excretion was assessed in water-loaded rats subjected to fasting or fasting and refeeding. In fed animals, naloxone had no effect on water or electrolyte excretion compared to saline injected controls. However, during fasting, which has been shown to activate endogenous opioid systems, naloxone had a marked natriuretic effect (43 +/- 10 vs. 11 +/- 4 muEq/100 g X 2 h, p less than 0.05). Naloxone increased the sodium excretion to a level not significantly different from fed animals. Potassium and water excretion were not significantly changed compared to saline injected rats. The results suggest that fasting activates a naloxone-sensitive mechanism for sodium retention, perhaps by increasing the release of endogenous opioid peptides, and that refeeding inhibits this mechanism.

Animals↗

The pathogenicity of Salmonella mbandaka in specific pathogen free rabbits.

Salmonella mbandaka was isolated from the lungs of three rabbits that developed a peracute disease and died three to eight weeks following extensive experimental manipulation. To examine the pathogenicity of this rare serotype, clinically normal, S. mbandaka-carrier rabbits were subjected to either corticosteroid immunosuppression alone or corticosteroid immunosuppression with a minor surgical procedure. Acute or peracute salmonellosis developed in one of two rabbits immunosuppressed only, and in three of four rabbits immunosuppressed and surgically manipulated. Stressful experimental procedures may precipitate episodes of clinical salmonellosis in rabbits harboring this organism. Salmonella mbandaka, should be considered a zoonotic agent in the laboratory environment.

Animals↗

Experimental Salmonella-associated conjunctivitis in cats.

Cats were infected experimentally with Salmonella typhimurium via the conjunctiva. Clinical signs consisted of lacrimation, conjunctivitis, blepharospasm, prominent nictitating membrane and scleral injection. These signs were accompanied by an absolute neutrophilia and conjunctival smears indicative of moderate to severe suppurative inflammation. Ocular signs disappeared by day 6 postinfection. Salmonella typhimurium was cultured intermittently from the inoculated conjunctivae and rectal swabs through day 7. At necropsy, mesenteric and cervical lymph nodes were enlarged. Histopathological findings included chronic conjunctivitis and lymphoid hyperplasia in cervical and mesenteric lymph nodes. This study confirms that S. typhimurium can cause a primary conjunctivitis and that the ocular route of infection can lead to fecal excretion of Salmonella, in the absence of other clinical manifestations.

Animals↗

Antinatriuretic effect of acute morphine administration in conscious rats.

The renal response to the acute administration of morphine was examined in conscious, chronically catheterized, nonhydrated rats. After control clearance periods, morphine sulfate was injected i.v. at 4 mg/kg followed by an infusion of 2 mg/kg X hr. Morphine caused an increase in urine flow which was variable in magnitude and duration. The initial diuresis was not maintained despite continued morphine administration and replacement of lost fluid. Compared to vehicle treatment morphine also induced marked sodium and chloride retention which was sustained throughout the 2-hr infusion period. There were no changes in blood pressure or heart during the clearance periods, although an initial transient hypotension and bradycardia were observed with morphine injection. There were no changes in glomerular filtration rate which could account for the antinatriuresis. Naloxone pretreatment blocked all of the observed renal responses. The results indicate that morphine exerts its effects on electrolyte excretion by enhancing renal tubular sodium or chloride reabsorption rather than changes in systemic hemodynamics or glomerular filtration rate. In a separate series of experiments, urine osmolality, osmolar clearance and free water clearance were estimated. All rats receiving morphine transiently excreted a hypotonic urine (minimum 183 +/- 23 mOsmol/kg of H2O) with a reduction in osmolar clearance and a sharp increase in free water clearance. These findings are consistent with a temporary inhibition of vasopressin release by morphine.

Animals↗

An enzyme linked immunosorbent assay for detection of antibodies to Corynebacterium kutscheri in experimentally infected rats.

An enzyme-linked immunosorbent assay (ELISA) which detects rat antibody to Corynebacterium kutscheri was developed and compared with a tube agglutination assay in two infectivity studies. In four groups of rats inoculated intratracheally with 100-fold dilutions of Corynebacterium kutscheri , mortality, lesions, and recovery of Corynebacterium kutscheri were confined to the two highest dose groups. Five of 17 (29%) test rats seroconverted within 14 to 21 days post-inoculation as assayed by ELISA; four of these five (80%) seroconverted within 42 to 98 days post-inoculation as assayed by tube agglutination. ELISA titers were one to 16 times greater than tube agglutination titers. In 15 rats challenged intranasally with 6.9 X 10(6) Corynebacterium kutscheri , clinical signs were observed in one of 15 (6.7%), and bacteriologic and histopathologic evaluations detected exposure to Corynebacterium kutscheri in three of 14 (21.4%) and one of 14 (7.1%) of the rats, respectively. Fourteen days post-inoculation, seroconversion was observed in 14 of 15 (93.3%) by ELISA, as compared to six of 15 (40%) by tube agglutination (p less than 0.001). The ELISA was more sensitive than tube agglutination through 21 days post-inoculation, while sera assayed 33 to 53 days post-inoculation had comparable titers in both assays. Specificity studies using four other Corynebacterium sp indicated that the Corynebacterium kutscheri ELISA cross reacted with two of four (50%) sets of corynebacterial antisera (Corynebacterium ulcerans and Corynebacterium equi) prepared in rats, whereas no cross reactivity was observed by tube agglutination.

Agglutination Tests↗

Mastitis caused by hemolytic Escherichia coli in the ferret.

Hemolytic Escherichia coli was isolated from the mammary glands of 8 ferrets with gangrenous mastitis. Clinical signs included firm swelling of one or more mammary glands and discoloration of the overlying skin. Peracute disease and acute septicemia were observed, and in some cases the animals rapidly became moribund. Antibiotic therapy alone did not alter the course of the disease. Wide surgical resection of the involved glands in combination with systemic antibiotic therapy (ampicillin 10 mg/kg, BID, and gentamicin 5 mg/kg, SID) was the most successful treatment. Histopathologic changes included extensive edema, hemorrhage, and necrosis, with a mixed leukocytic infiltrate and large numbers of bacteria. The agent of this disease was isolated from rectal swab specimens from clinically normal ferrets as well as ferrets that had mastitis.

Animals↗

Bur buttercup poisoning of sheep.

Bur buttercup (Ceratocephalus testiculatus) has not been considered to be poisonous, but the sudden death loss of 150 ewes while grazing it prompted study of the plant. It was found that bur buttercup can be highly toxic to sheep, with a lethal dose being as little as 500 g of green plant for a 45-kg sheep. Clinical signs of bur buttercup poisoning are weakness, depression, diarrhea, labored breathing, anorexia, and occasional fever. Postmortem findings include inflammation and edema of the rumen; hemorrhage in the left ventricle of the heart; congestion of the lungs, liver, and kidneys; and excessive fluid in the thoracic and abdominal cavities.

Animals↗

Allergenic properties of naturally occurring cannabinoids.

The guinea pig maximization test was used to determine the potential of seven cannabinoids to produce allergic contact dermatitis. delta 9-Tetrahydrocannabinol and cannabinol were found to be extreme (Grade V) sensitizers. Cannabidiol, delta 8-tetrahydrocannabinol, and cannabichromene were moderate (Grade III) sensitizers. Cannabigerol and cannabinol methyl ether were not sensitizers. Most of the cannabinoids were found to be allergenically cross-reactive. Additionally, it was shown that the presence of a free 1'-hydroxyl group was required for sensitization, but not to elicit a response in sensitive animals.

Allergens↗

Effects of the administration of coca alkaloids on the primary immune responses of mice: interaction with delta 9-tetrahydrocannabinol and ethanol.

The effects of cocaine, its metabolites, and other alkaloids from Erythroxylon coca on the primary immune responses of ICR mice to sheep red blood cells (sRBC) and dinitrofluorobenzene (DNFB) were studied. The Jerne hemolytic plaque assay (PFC) was used to evaluate the humoral immune response to sheep red blood cells, and the delayed type hypersensitivity (DTH) response to DNFB was used to study cellular immune responsiveness. Drugs were given in single daily po doses for 5 consecutive days beginning on the day of immunization or 3 days prior to and on Days 3 and 4 after immunization. Inhibition of both PFC and DTH responses occurred at doses of 15 to 60 mg/kg of cocaine and was greatest when fed during immunization. Five other alkaloids also suppressed the PFC and/or DTH response. Cocaine was more suppressive than the six other alkaloids tested. Ethanol (5 g/kg) did not suppress the DTH response and only marginally suppressed the PFC response. delta 9-THC inhibited the PFC response at doses of 10 mg/kg and marginally suppressed the DTH response at doses of 30 mg/kg, but not at other doses ranging from 10 to 90 mg/kg. Coadministration of 5 g/kg ethanol and 15 mg/kg cocaine resulted in 50% antagonism of effects of cocaine on the PFC response and complete antagonism of the suppression of the DTH response, but only if these substances were given during the period of immunization. Like ethanol, delta 9-THC also abolished the inhibitory effects of cocaine on the PFC and DTH response but only if coadministered during the period of immunization. Coadministration of ethanol and delta 9-THC resulted in synergistic inhibition of both DTH and PFC responses.

Alkaloids↗