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Biomedical subjects

J C Murphy

Publications and source records attributed to J C Murphy.

At least 55 records · Page 3Linked to original sources

Probable transmission of Chlamydia psittaci from a macaw to a cat.

A 5-year-old Siamese cat developed unilateral mucopurulent ocular discharge and conjunctivitis 1 month after the introduction of a macaw into the household. Despite treatment with antimicrobial ophthalmic ointment, the conjunctivitis became bilateral and other systemic signs developed. Intracellular inclusions consistent with a Chlamydia psittaci infection were detected in conjunctival epithelial cells stained with a fluorescein-labeled monoclonal antibody. Chlamydia psittaci was isolated from samples obtained by conjunctival scraping. Subsequently, C psittaci was recovered in samples obtained from the feces of the bird. The cat and the bird were successfully treated with doxycycline. Historic and epidemiologic findings supported the theory of orthozoonotic transmission of C psittaci from the bird to the cat.

Animals↗

Animal and public health implications of gastric colonization of cats by Helicobacter-like organisms.

The bacterial genus Helicobacter contains a number of species which colonize the gastric mucosa of mammals. Natural and/or experimental gastric pathology has been correlated with colonization in humans and a wide variety of animal species. Historical reports in the literature suggest that a high percentage of cats are colonized by large, spiral, gastric helicobacter-like organisms (GHLOs). One of these bacteria (Helicobacter felis) has been isolated on artificial media and has experimentally caused gastritis in gnotobiotic dogs. This study surveyed the prevalence of helicobacter colonization in random-source cats by using the urease assay. Histologic examination was performed to determine the degree of associated pathology present. GHLOs associated with chronic gastritis were present in 70% of the juvenile and 97% of the adult cats studied. Although further study is needed to determine specifically what role GHLOs play in feline gastrointestinal disease, these results indicate that helicobacter colonization should be considered in the pathogenesis of feline gastroenteropathy. Furthermore, the high prevalence of feline infection is interesting because cats have recently been implicated as a potential reservoir for human infection by helicobacter-like organisms.

Animals↗

Intracellular Campylobacter-like organism from ferrets and hamsters with proliferative bowel disease is a Desulfovibrio sp.

Proliferative bowel disease is an intestinal disorder of a variety of domestic animals associated with the presence of an intracellular Campylobacter-like organism (ICLO). We have identified the ICLO obtained from a ferret with proliferative colitis by 16S rRNA sequence analysis. In this ferret, proliferative bowel tissue containing the ICLO had translocated to the mesenteric lymph nodes, omentum, and liver. The 16S rRNA genes of the ICLO were amplified from an infected fragment of extraintestinal tissue by using universal prokaryotic primers. Approximately 1,480 bases of the amplified 16S rRNA gene were sequenced by cycle sequencing. Comparison of the sequence of the ICLO with those of over 400 bacteria in our data base indicated that the sequence of the ICLO was most closely related to that of Desulfovibrio desulfuricans (87.5% similarity). Phylogenetic analysis with 12 Desulfovibrio species and 20 species from related genera placed the ICLO in a subcluster within the genus Desulfovibrio with D. desulfuricans and 5 other Desulfovibrio species. We will refer to this organism as the intracellular Desulfovibrio organism (IDO). Specific primers were produced for PCR amplification of a 550-base fragment of the 16S rRNA gene of the IDO in proliferative intestinal tissue samples. This unique 550-base segment was amplified from samples of frozen intestinal tissue from nine ferrets and three hamsters with ICLO-associated disease but not in four intestinal tissue samples from animals without the ICLO-associated disease. The 550-base amplified products from the bowel tissues of one hamster and one ferret were fully sequenced. The ferret IDO partial sequence was identical to the previously determined 16S rRNA sequence over its length, and the hamster IDO sequence differed by a single base. The same intracellular organism has been identified in proliferative intestinal tissues of swine and that the organism has been successfully maintained in tissue culture. The availability of specific primers for PCR-based detection of this intracellular Desulfovibrio organism will aid in the determination of its role in the pathogenesis of proliferative bowel disease in a variety of infected hosts.

Animals↗

Evaluation of detomidine anesthetic combinations in the rabbit.

Detomidine, a potent alpha 2-adrenergic receptor agonist, was chosen for study alone and in combination with ketamine with or without diazepam. Four regimens were evaluated: detomidine (150 micrograms/kg of body weight) alone (D); ketamine (35 mg/kg) and detomidine (150 micrograms/kg) (KD); ketamine (35 mg/kg) and high-dose detomidine (300 micrograms/kg) (KDh); and ketamine (35 mg/kg), diazepam (1 mg/kg), and detomidine (150 micrograms/kg) (KDD). The same six rabbits were anesthetized with each combination at weekly intervals. Atropine (0.04 mg/kg) was administered as a preanesthetic 5 min prior to test substance administration. All agents were administered IM, except for diazepam, which was administered IV. Heart and respiratory rates, mean arterial blood pressure, and arterial blood gas tensions were measured. Pedal, palpebral, and righting reflexes also were evaluated. Cardiopulmonary depression, as indicated by decrease in heart and respiratory rates, blood pH, PO2, and increase in PCO2, was observed in all groups. With the exception of heart rate, detomidine used alone caused the least depression of these parameters. Reflexes were consistently lost only after KDh and KDD administrations. The pedal reflex, used as an index of anesthetic depth, was lost in response to KDh and KDD for 56.7 +/- 11.6 and 43.8 +/- 7.4 min, respectively (mean +/- SEM). Three of the six rabbits were anorectic after KDh administration. Necropsy and histologic evaluation revealed myocardial necrosis and fibrosis in five animals. Due to the inconsistent reflex loss in response to KD and D and inappetance associated with KDh, these combinations were not considered safe or reliable.(ABSTRACT TRUNCATED AT 250 WORDS)

Analgesics↗

Total knee arthroplasty after patellectomy.

We compared the outcome of total knee arthroplasty in 19 patients who had had previous patellectomy with the results in a matched series of arthroplasties performed on knees in which the patella was intact. The mean follow-up was 63 months (21 to 114). In the study group, the outcome was poor in five patients. There was instability in the coronal plane in three patients and persistent pain in four. Three supracondylar fractures occurred. The overall complication rate was 36%. In the control group, pain was relieved in every case and there were no complications. Total knee arthroplasty has a higher complication rate and inferior results if the knee has undergone prior patellectomy.

Adult↗

Estimation of glomerular filtration rate and evaluation of renal function in ferrets (Mustela putorius furo).

Three methods of determining glomerular filtration rate (GFR) were performed in adult ferrets, 9 months to 7 years old. Endogenous creatinine clearance was determined, using serum and urine creatinine values obtained during 24- and 48-hour collection periods from 27 ferrets housed in metabolic cages. Creatinine and radiolabeled inulin were administered to 12 female ferrets by constant IV infusion during isoflurane-induced anesthesia. Serial 20-minute urine collections, together with serum samples obtained at the midpoint of urine collection, provided measures for clearance calculations of these substances. Mean +/- SD endogenous creatinine clearance in ferrets for metabolic cage collections was 2.50 +/- 0.93 ml/min/kg of body weight. There were no significant differences between the 24- and 48-hour clearance rates. Mean inulin clearance was 3.02 +/- 1.78, and mean exogenous creatinine clearance was 3.32 +/- 2.16 ml/min/kg. Analysis of variance, using least-squared means adjustment, did not yield any significant differences between inulin and exogenous creatinine clearance rates. Exogenous creatinine clearance-to-inulin clearance ratio was 0.99 +/- 0.46, and there was significant correlation between the 2 methods (r = 0.82, P = 0.0001). Significant body temperature effects on inulin or exogenous creatinine clearance were not found. Infused inulin clearance, the generally preferred method for GFR calculation in mammalian species, was significantly (P = 0.0069) higher in younger (3.65 ml/min/kg) vs older ferrets (2.29 ml/min/kg). Results of this study indicate that inulin clearance is an adequate measure of GFR in ferrets as it is in other species. Compared with inulin clearance, exogenous creatinine clearance also provides a reliable estimate of GFR in ferrets.

Aging↗

Estradiol-17 beta-secreting adrenocortical tumor in a ferret.

Severe generalized alopecia and marked vulvar enlargement were observed in a 5-year-old spayed ferret with high serum estradiol concentrations. A neoplastic left adrenal gland was removed. Staining of the neoplastic cells for estradiol was demonstrated by use of immunohistochemistry. Clinical findings in this ferret were typical of adrenal-associated endocrinopathy, a syndrome characterized by increased secretion of adrenocortical hormones by hyperplastic or neoplastic adrenal glands.

Adrenal Cortex Neoplasms↗

Functional islet cell tumor in six ferrets.

Functional islet cell tumor was diagnosed in 6 ferrets. Prominent clinical signs included weight loss, hind limb weakness, ptyalism, and tremors. The diagnosis was made on the basis of 2 or more of the following methods and confirmed by histologic examination of biopsied tissue: hypoglycemia on routine serum biochemical analysis, clinical signs of hypoglycemia, simultaneous development of hypoglycemia (44 +/- 9.9 mg/dl; mean +/- SD), and hyperinsulinemia (58 +/- 18.4 microU/ml; mean +/- SD) after food was withheld for 4 hours. Surgical resection of affected tissue was associated with clinical improvement in all cases. Foci of metastasis were found in 1 ferret. Diazoxide was unsuccessful in controlling persistent postsurgical hypoglycemia in 2 ferrets. Additional functional islet cell tumors were identified in 5 of 6 ferrets at necropsy. Functional islet cell tumors are important neoplasms of older ferrets. Preventive health programs for ferrets > 3 years old should include monthly weight determinations and biannual CBC and serum biochemical analysis.

Adenoma, Islet Cell↗

International Commission for Protection Against Environmental Mutagens and Carcinogens. Power frequency electric and magnetic fields: a review of genetic toxicology.

Epidemiologic studies have reported a modestly increased risk of childhood leukemia associated with certain electric power wire configurations. Since cancer likely involves DNA damage, this review discusses the evidence of direct and indirect genetic toxicity effects for both electric and magnetic fields at 50- and 60-Hz and miscellaneous pulsed exposures. Exposure conditions vary greatly among different end points measured, making comparisons and conclusions among experiments difficult. Although most of the available evidence does not suggest that electric and/or magnetic fields cause DNA damage, the existence of some positive findings and limitations in the set of studies carried out suggest a need for additional work.

Animals↗

MNNG-induced gastric carcinoma in ferrets infected with Helicobacter mustelae.

N-Methyl-N-nitro-N'-nitrosoguanidine (MNNG) is a gastric carcinogen in several animal species and has been used in a number of systems to dissect the co-carcinogenic potential of various compounds in the induction of gastric adenocarcinoma. Recent epidemiological evidence suggests that Helicobacter pylori may play a role as a co-carcinogen in the etiology of this tumor in humans and we have been interested in developing an animal model to study this possibility. A related organism, H. mustelae, naturally colonizes the ferret stomach and causes persistent chronic gastritis. The pathology elicited by H. mustelae in ferrets has many similarities with the human disease including different stages of multifocal atrophic gastritis which underlie the gastric ulcer and gastric carcinoma syndrome. There is little evidence, however, demonstrating the susceptibility of ferrets toward chemical carcinogenesis. We have consequently undertaken a study to ascertain whether 10 6-month-old female ferrets given a single oral dose of MNNG (50-100 mg/kg) would develop adenocarcinoma of the stomach. Five age-matched unmanipulated control animals were included for comparative purposes. All 15 ferrets were infected with H. mustelae. Nine of 10 ferrets dosed with MNNG developed gastric adenocarcinoma (29-55 months after dosing), while none of the five historical control ferrets examined an average of 63 months after the initiation of the study developed gastric tumors. By comparison, we have not observed gastric adenocarcinoma, nor has it been reported, in > 10 years of observation of untreated ferrets naturally infected with H. mustelae. The H. mustelae-infected ferret, with demonstrated susceptibility to a gastric carcinogen, plus the recent availability of specific pathogen-free ferrets, should now allow longitudinal studies in vivo to probe the role of Helicobacter in the development of gastric cancer.

Adenocarcinoma↗

Local and systemic immune responses in murine Helicobacter felis active chronic gastritis.

Helicobacter felis inoculated per os into germfree mice and their conventional non-germfree counterparts caused a persistent chronic gastritis of approximately 1 year in duration. Mononuclear leukocytes were the predominant inflammatory cell throughout the study, although polymorphonuclear cell infiltrates were detected as well. Immunohistochemical analyses of gastric mucosa from H. felis-infected mice revealed the presence of mucosal B220+ cells coalescing into lymphoid follicles surrounded by aggregates of Thy-1.2+ T cells; CD4+, CD5+, and alpha beta T cells predominated in organized gastric mucosal and submucosal lymphoid tissue, and CD11b+ cells occurred frequently in the mucosa. Follicular B cells comprised immunoglobulin M+ (IgM+) and IgA+ cells. Numerous IgA-producing B cells were present in the gastric glands, the lamina propria, and gastric epithelium. Infected animals developed anti-H. felis serum IgM antibody responses up to 8 weeks postinfection and significant levels of IgG anti-H. felis antibody in serum, which remained elevated throughout the 50-week course of the study.

Animals↗

Long-term results of Charnley low-friction arthroplasty in young patients.

We report the long-term outcome of 218 Charnley low-friction arthroplasties in 141 patients who were 40 years old or younger at the time of surgery. The minimum follow-up was ten years with a mean of 16 years. The probability of the femoral component surviving 20 years was 86% and of the acetabular component, 84%. The chance that both components would survive for this period was 75%. The pathological diagnosis significantly influenced implant survival. In rheumatoid patients the probability of both components surviving at 20 years was 96% compared with 51% in patients with osteoarthritis. Clinical assessment of 103 patients (166 hips) in whom the arthroplasty was still functioning showed that 94% of hips had minimal pain or none. We conclude that in young patients cemented total hip replacement is a good procedure for those with rheumatoid arthritis but that the results are much less reliable in those with osteoarthritis.

Adolescent↗

Comparison of morning or bedtime insulin with and without glyburide in secondary sulfonylurea failure.

OBJECTIVES: New treatment options are needed for glycemic control in NIDDM. We evaluated the effects of bedtime or morning insulin treatment, combined with daytime glyburide or given alone. RESEARCH DESIGN AND METHODS: Twenty-nine male patients with NIDDM, mean age 63 +/- 1.7 yr, body weight 124 +/- 2.98% of DBW, received a maximum glyburide dose (20 mg/day) for a minimum of 6 wk, to confirm sulfonylurea failure. Human lente insulin was added for 12 wk either AM (n = 14) or HS (n = 15) and adjusted to obtain fasting euglycemia (FPG; combination treatment phase). Glyburide was then stopped, and insulin was continued for 6 wk, aiming for normal FPG (insulin phase). RESULTS: After combination treatment phase, FPG decreased (P < 0.02) from 12.43 +/- 0.68 to 5.73 +/- 0.65 mM (AM) and from 12.68 +/- 0.76 to 5.51 +/- 0.48 mM (HS) (AM vs. HS, NS). Postbreakfast, presupper, and 0200 AM plasma glucose levels fell equally (P < 0.02) except for 1-h postprandial (AM 12.46 +/- 0.51 mM, HS 10.88 +/- 0.62 mM, AM vs. HS, P < 0.1). Mean HBA1c fell similarly in both AM and HS groups. At 2 wk of the insulin phase, FPG was higher in AM than HS, 9.8 +/- 0.76 vs. 7.56 +/- 0.7 mM (P < 0.1). At the end of insulin phase, plasma glucose levels were similar to the end of combination treatment phase, but the insulin dose had to be raised in AM by 39% (P < 0.02) and HS by 30% (P < 0.05). After the combination treatment phase, fasting C-peptide was significantly suppressed in HS group only, from 1.22 +/- 0.12 to 0.82 +/- 0.09 nM (P < 0.02). At the end of insulin phase, fasting C-peptide was further suppressed in both groups, but 2-h postprandial C-peptide levels decreased significantly in AM group only, from 1.85 +/- 0.23 to 1.42 +/- 0.13 nM (P < 0.02). Triglycerides and total and HDL cholesterol did not change significantly after either combination treatment phase or insulin phase. Mean weight gain was 6.5 lb during combination treatment phase (NS from baseline), without further change during insulin phase. Hypoglycemic reactions, all mild, were recorded at a rate of 1.35/patient in the AM group and 0.4/patient in the HS group (P < 0.025). CONCLUSIONS: Normal fasting glycemia and near-normal postprandial glucose profile could be obtained with combination therapy in NIDDM. Results were similar if insulin, alone or in combination with glyburide, was given before breakfast or at bedtime, but hypoglycemic reactions were more common with conventional morning insulin injections.

Adult↗

Parvovirus-associated syndrome (Aleutian disease) in two ferrets.

There is a paucity of information regarding natural Aleutian disease, caused by a parvovirus in ferrets. With the increasing popularity of ferrets as household pets and laboratory animals, and with the advent of a USDA-approved rabies vaccine, the occurrence and the etiopathogenesis of naturally acquired diseases in ferrets needs to be documented. We present the clinical and laboratory findings associated with Aleutian disease in 2 domestic ferrets, one with the chronic wasting form of the disease and one with the central nervous system form.

Aleutian Mink Disease↗

Role of Helicobacter felis in chronic canine gastritis.

Five gnotobiotic Beagle dogs were orally inoculated with a pure culture of Helicobacter felis. The remaining two littermates served as contact controls. Thirty days after infection, all animals were euthanatized and specimens were collected for evaluation. In infected dogs, H. felis was recovered from all areas of the stomach. Colonization was heaviest in the fundus and antrum. H. felis was not cultured from any segment of the gastrointestinal tract distal to the duodenum. Two weeks after infection, all five infected dogs had detectable IgM and IgG serum antibody to H. felis, whereas control dogs had no measurable H. felis serum antibody throughout the study. Histopathologic changes in the stomachs of infected dogs included large numbers of lymphoid nodules throughout all regions of the gastric mucosa and were most numerous in the fundus and body. A mild, diffuse lymphocytic infiltrate with small numbers of plasma cells and eosinophils was also present in the subglandular region of all portions of the gastric mucosa. Electron microscopic examination revealed large numbers of spiral-shaped H. felis in gastric mucus adjacent to or superimposed over the areas of inflammation. Occasionally, however, H. felis was observed within the canaliculi of gastric parietal cells. Histopathologic changes in the stomachs of the contact control dogs were limited to focal infiltrates of eosinophils and small aggregates of lymphocytes in the subglandular portions of the gastric mucosa in one animal. Infection with H. felis is a likely cause of naturally occurring lymphofollicular gastritis.

Animals↗

Comparison of immune response potentiation and in vivo inflammatory effects of Freund's and RIBI adjuvants in mice.

Freund's adjuvant and the RIBI adjuvant system were compared for their immune potentiating and toxic effects. Each adjuvant was administered with benzo(a)pyrene (BaP), a nonimmunogenic hapten, conjugated to a bovine gamma globulin (BGG) carrier protein to 10 mice intraperitoneally. Complete Freund's adjuvant was used at initial immunization, while incomplete Freund's was used for booster immunizations. Five mice were given the immunogen conjugate (BaP-BGG) in saline as a control. Antibody titers were determined by ELISA to both hapten and carrier after each of the two booster immunizations. Titers to BaP were 2- and 27-fold higher for RIBI than for Freund's after each of two booster immunizations. Titers to bGG were 119 and 12-fold higher for RIBI compared with Freund's. Titers to both immunogens were markedly less when administered in saline. Body weights were monitored in all three groups for the duration of the study. No differences were observed among the three groups. Mice from each group were euthanized at regular intervals to assess pathology. Splenic weight:body weight ratios were determined at the time of necropsy, and no differences were noted among the three groups. Granulomatous inflammatory lesions were most severe in the Freund's immunized mice, less severe in those immunized with RIBI, and least with saline. Results indicate that the RIBI system was more effective in potentiating an immune response and elicited less tissue reaction than did Freund's adjuvant with this particular immunogen.

Adjuvants, Immunologic↗

Helicobacter felis gastritis in gnotobiotic rats: an animal model of Helicobacter pylori gastritis.

The gastric spirillum Helicobacter felis, originally isolated from the cat stomach, colonizes the stomachs of germfree rats. Studies were designed to examine the pathological and serological responses of germfree rats inoculated orally with H. felis. At 2 weeks postinoculation, the gastric mucosa of germfree rats had lymphocytes and eosinophils scattered in small foci throughout the subglandular region of the antrum. Small numbers of lymphocytes were present in the subglandular portion of the antral mucosa that focally extended through the lamina propria towards the luminal surface. Eight weeks postinoculation, the inflammation was confined to the antrum. It was characterized by increased numbers of lymphocytes and eosinophils in the subglandular areas, with focal aggregates of lymphocytes in the submucosa. Some lymphoid aggregates extended from the submucosa through the muscularis mucosa and lamina propria to the luminal surface. H. felis was demonstrated with the Warthin-Starry stain, bacterial culture, and urease assay, particularly in the antrum. H. felis also produced a significant immunoglobulin G antibody titer at 2, 4, and 8 weeks postinoculation as well as a transitory immunoglobulin M response at 2 to 4 weeks postinoculation. Contact control rats were not infected, inferring that fecal-oral spread of H. felis did not occur.

Animals↗