Pattern of maternal circulating CRH in laboratory-housed squirrel and owl monkeys.

The anthropoid primate placenta appears to be unique in producing corticotropin-releasing hormone (CRH). Placental CRH is involved in an endocrine circuit key to the production of estrogens during pregnancy. CRH induces cortisol production by the maternal and fetal adrenal glands, leading to further placental CRH production. CRH also stimulates the fetal adrenal glands to produce dehydroepiandrostendione sulfate (DHEAS), which the placenta converts into estrogens. There are at least two patterns of maternal circulating CRH across gestation among anthropoids. Monkeys examined to date (Papio and Callithrix) have an early-to-mid gestational peak of circulating CRH, followed by a steady decline to a plateau level, with a possible rise near parturition. In contrast, humans and great apes have an exponential rise in circulating CRH peaking at parturition. To further document and compare patterns of maternal circulating CRH in anthropoid primates, we collected monthly blood samples from 14 squirrel monkeys (Saimiri boliviensis) and ten owl monkeys (Aotus nancymaae) during pregnancy. CRH immunoreactivity was measured from extracted plasma by using solid-phase radioimmunoassay. Both squirrel and owl monkeys displayed a mid-gestational peak in circulating CRH: days 45-65 of the 152-day gestation for squirrel monkeys (mean±SEM CRH=2,694±276 pg/ml) and days 60-80 of the 133-day gestation for owl monkeys (9,871±974 pg/ml). In squirrel monkeys, circulating CRH declined to 36% of mean peak value by 2 weeks before parturition and then appeared to increase; the best model for circulating CRH over gestation in squirrel monkeys was a cubic function, similar to previous results for baboons and marmosets. In owl monkeys, circulating CRH appeared to reach plateau with no subsequent significant decline approaching parturition, although a cubic function was the best fit. This study provides additional evidence for a mid-gestational peak of maternal circulating CRH in ancestral anthropoids that has been lost in the hominoid lineage.

Midcycle and luteal elevations of follicle stimulating hormone in squirrel monkeys (Saimiri boliviensis) during the estrous cycle.

Follicle stimulating hormone (FSH) has fundamental importance in reproductive function, but its cyclic pattern has not previously been described in the squirrel monkey, due primarily to the lack of a suitable assay. An homologous radioimmunoassay (RIA) based on recombinant cynomolgus FSH measured changes in serum FSH relative to patterns of bioactive luteinizing hormone (LH), estradiol, and progesterone during the estrous cycle. FSH was observed to have a sharp peak during the late follicular phase coincident with the LH surge and then rose again during the luteal phase. Estradiol was low except for the midcycle rise, suggesting an inhibitory relationship. The rat granulosa cell in vitro FSH bioassay confirmed high levels of this hormone. Measurement of FSH in the squirrel monkey has found a pattern different from Old World primates in the luteal phase, which may provide insight into the reproductive mechanisms of this species.

Penile vibratory stimulation yields increased spermatozoa and accessory gland production compared with rectal electroejaculation in a neurologically intact primate (Saimiri boliviensis).

Assisted reproductive techniques require an efficient semen collection procedure in cases of ejaculatory dysfunction. Anejaculation may be of psychogenic or neurogenic origin but can be overcome with stimulatory techniques. Penile vibratory stimulation (PVS) therapy for anejaculation has recently emerged as an alternative to rectal probe electroejaculation (RPE) and more invasive testicular procedures. Comparison of the stimulatory procedures in neurologically intact subjects is not ethically possible due to the discomfort involved with electroejaculation, and comparison in spinal cord injured men may be compromised due to the intricate effects of chronic denervation on semen quality. We have previously shown the efficacy of PVS in a non-human primate, the squirrel monkey. A cross-over study design comparing semen collected by PVS and RPE was employed during the breeding season in which 15 donor males were divided into two groups. One group received PVS and the other RPE, then, three days later, treatments were reversed. Twelve of 15 animals responded to PVS (80%), all with spermatozoa in the ejaculate. Mean volume (436 +/- 90 microl), motility (80.6 +/- 4.3%), and total spermatozoa (32.8 +/- 10.2 x 10(6)) were significantly higher than in the semen after RPE. RPE resulted in ejaculation in all 15 animals with a semen volume of 205 +/- 25 microl, but fewer samples contained spermatozoa (9/15) resulting in a low total count (0.5 +/- 0.3 x 10(6)). The motility was reduced in those samples with spermatozoa (n = 9; 44.1 +/- 11.4%). Additionally, accessory gland activity was measured via the seminal vesicle and prostrate markers, fructose and citric acid, respectively. The PVS specimens had significantly more fructose (2.9 +/- 0.7 mg/ejaculate) and citric acid (0.46 +/- 0.14 mg/ejaculate) compared to RPE collected specimens (1.2 +/- 0.3 mg/ejaculate and 0.24 +/- 0.04 mg/ejaculate, respectively). In conclusion, PVS produces a much greater sperm yield and increased accessory gland secretion compared to RPE in our neurologically intact squirrel monkey model.

Isolation of a novel Helicobacter species, Helicobacter cholecystus sp. nov., from the gallbladders of Syrian hamsters with cholangiofibrosis and centrilobular pancreatitis.

A filamentous, gram-negative, motile bacterium with a single polar sheathed flagellum was isolated from gallbladders of hamsters with cholangiofibrosis and centrilobular pancreatitis. Bacteria grew under microaerophilic conditions at 37 and 42 degrees C, were oxidase, catalase, arginine aminopeptidase, and L-arginine arylamidase positive, reduced nitrate to nitrite, were resistant to cephalothin, and exhibited intermediate susceptibility to nalidixic acid. Sequence analysis of the 16S rRNA gene indicated that the bacterium was a novel member of the Helicobacter genus, most closely related to Helicobacter pametensis. We propose to name this bacterium Helicobacter cholecystus. In epidemiologic studies, isolation of H. cholecystus correlated strongly with the presence of cholangiofibrosis and centrilobular pancreatitis; however, further studies are needed to define the role of this bacterium in pathogenesis.

Naturally occurring aortic aneurysms in owl monkeys (Aotus spp.).

Spontaneous aortic aneurysms were diagnosed in 22 owl monkeys (Aotus spp.) at necropsy. There were 6 males and 16 females. Clinical findings varied including weight loss, weakness, and lethargy and were not present in all animals. Aortic lesions ranged in size from 2 mm to 3 cm in diameter. Nineteen of the aneurysms were classified histologically as dissecting and three as saccular. Lesions occurred less often in karyotype I monkeys than in karyotype II or III monkeys. The etiopathogenesis of aortic aneurysm in owl monkeys is unknown.

Treatment of Trichophyton mentagrophytes infection in rabbits.

Copper sulfate and a metastabilized chlorous acid/chlorine dioxide (MECA) compound were evaluated for efficacy in treating Trichophyton mentagrophytes infection in rabbits. Forty rabbits naturally infected with T mentagrophytes were allotted to 5 treatment groups: nontreated control, sham dip, 1% copper sulfate dip, MECA dip, and MECA spray. Results of lesion culture, regression of gross lesions, and histopathologic findings were documented. Copper sulfate and MECA were effective in treating clinical dermatophytosis and in decreasing T mentagrophytes carrier status in rabbits.

Tyzzer disease in hamsters and gerbils from a pet store supplier.

An episode of Tyzzer disease (Bacillus piliformis) developed in hamster and gerbil colonies of a pet store supplier. The incidence of diarrhea and subsequent mortality was high. The only important necropsy findings were cecal distention and mesenteric lymphadenopathy in the hamsters. Histologically, necrotizing typhlitis and hepatitis with associated B piliformis organisms were seen in both species. This case was unusual because the most consistent gross lesion associated with Tyzzer disease--hepatomegaly with multiple pale foci of hepatic necrosis--was not seen. Tyzzer disease is widespread geographically and among species; B piliformis has been reported to cause disease in at least 18 species of animals including hamsters, gerbils, rabbits, guinea pigs, horses, cows, dogs, and cats. Clinical signs of disease are nonspecific, and treatment is difficult because the organism is intracellular, although tetracycline and oxytetracycline reportedly have controlled mortality.

Naturally acquired enteric adenovirus infection in Syrian hamsters (Mesocricetus auratus).

Intranuclear inclusions indicative of adenovirus infection were detected microscopically in formalin-fixed intestinal tissues from preweanling Syrian hamsters. The amphophilic intranuclear inclusion bodies were observed in ileal enterocytes from 16-to 24-day-old hamsters. Electron microscopy revealed large numbers of 72 +/- 3-nm viral particles typical of adenoviridae in enterocytic nuclei. Serum antibodies reacted with mouse adenovirus strains K87 and, to a lesser extent, FL, by indirect fluorescent antibody testing. Clinical disease was not associated with the adenoviral infections. Hamsters from 10 production colonies, including all major commercial Syrian hamster suppliers in the United States, were surveyed and all had serologic or histopathologic evidence of adenovirus infection.

Multidrug chemotherapy of tuberculosis in rhesus monkeys.

Occurrence of tuberculosis caused by Mycobacterium bovis in a colony of rhesus monkeys allowed evaluation of a modern multidrug therapeutic regimen. Fifteen tuberculin positive rhesus monkeys with disseminated tuberculosis were evaluated for extent of disease by radiographic techniques, physical examination and laparotomy prior to treatment. Monkeys were divided into treatment groups of 3, 6 and 12 months duration and were treated once daily with isoniazid, rifampin and ethambutol. All animals survived their treatment course, had marked clinical improvement and rapid resolution of radiographically demonstrable lesions. Lesion regression evaluated by necropsy and histopathology correlated positively with length of treatment interval. Mycobacterium bovis was not isolated from any animal following treatment. Multidrug chemotherapy of tuberculosis was considered successful and practical in rhesus monkeys at the 12 month treatment interval. Chemotherapy may provide a reasonable alternative to destruction of valuable animals infected with tuberculosis.

Colonic impaction in guinea pigs fed a chemically defined diet: a case report.

Pathogen-free female Hartley guinea pigs were divided into four diet groups to determine optimal nitrogen requirements for growth, pregnancy and lactation. Three chemically defined test diets varying in total nitrogen were compared with commercial guinea pig feed. Within 13 days, 24 of 78 animals from the three test diet groups died or required euthanasia. Affected guinea pigs were depressed, lost weight and had distended abdomens. Distension, impaction and, in most cases, rupture of the spiral of the ascending colon and subsequent peritonitis were observed at necropsy. Husbandry changes which resulted in a decreased incidence of impactions included increased acclimatization time on commercial feed post-shipping, decreased animal density per cage and cessation of water medication with oxytetracycline.

Cryptosporidiosis in guinea pigs: a retrospective study.

Cryptosporidiosis was diagnosed in 81 guinea pigs (Cavia porcellus) from 1979 through 1985 at a research animal diagnostic laboratory. Most of the guinea pigs were juveniles of Hartley stock and originated from 6 commercial laboratory animal suppliers or from one pet store supplier. Common clinical signs reported were failure to gain weight, weight loss, diarrhea, and death. At necropsy, macroscopic findings included emaciation, hyperemia of the small intestine, serosal edema of the cecal wall, and increased fluidity of ingesta throughout the intestines. Oval to round cryptosporidia (1 to 4 microns) were seen microscopically within or on the brush border of mucosal epithelial cells from the duodenum through the cecum. Acute histologic lesions consisted of necrosis and sloughing of enterocytes at the villus tips, inflammation, hyperemia and edema of the lamina propria, and hyperplasia of crypt epithelium. More chronic lesions consisted of marked villus bridging or villus fusion and blunting, metaplasia of the mucosal epithelium, and lymphocytic infiltration of the lamina propria.

Comparison of serological tests for detection of antibodies to Sendai virus in rats.

The sensitivities of the enzyme-linked immunosorbent assay, complement fixation and hemagglutination inhibition tests for detection of serum antibodies to Sendai virus were compared. Virus antibody-free, 4-week-old, female Fischer 344 rats were inoculated intranasally with either egg-propagated Sendai virus or a noninfectious egg control preparation. None of the rats became ill clinically or developed pulmonary lesions characteristic of Sendai virus infection. The enzyme-linked immunosorbent assay was the most sensitive of the three tests, particularly in detection of early antibodies to Sendai virus and detection of small amounts of antibody.

Pathologic changes of experimental simian varicella (Delta herpesvirus) infection in African green monkeys (Cercopithecus aethiops).

Gross and microscopic lesions of experimental simian varicella (Delta herpesvirus) infection in African green monkeys (Cercopithecus aethiops) are described. In stratified squamous epithelium, such as the epidermis, tongue, and esophagus, focal areas of epidermal hyperplasia, ballooning degeneration, and blood-filled vesicle formation with ulceration were apparent. Most visceral organs were involved, and the changes included necrosis, hemorrhage, and characteristic intranuclear eosinophilic inclusions in a variety of cells. A generalized vascular involvement was present with intranuclear inclusions in the endothelial and smooth muscle cells in various organs. The nervous system was normal on gross and microscopic examination. Virus titer and serum transferase values were correlated with the clinical signs of infection.