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Biomedical subjects

M Bush

Publications and source records attributed to M Bush.

At least 55 records · Page 3Linked to original sources

Dubin-Johnson-like syndrome in golden lion tamarins (Leontopithecus rosalia rosalia).

On routine blood screens, persistent conjugated hyperbilirubinemia was discovered in two groups of closely related adult female golden lion tamarins (Leontopithecus rosalia rosalia, n = 8). Bromosulfophthalein (BSP) retention tests were performed on four hyperbilirubinemic and three control tamarins. BSP excretion was delayed in hyperbilirubinemic tamarins as compared with controls. Grossly, liver of affected tamarins was dark brown to black, with a prominent reticulated pattern. Histologic examination revealed abundant intrahepatic pigment, primarily in a centrilobular and midzonal distribution. Most of the pigment did not react with Perls' Prussian blue method for iron, Hall's method for bilirubin, or the Armed Forces Institute of Pathology acid-fast method for lipofuscin but was positive with Fontana and lipofuscin-ferric ferricyanide reduction techniques. Liver from control golden lion tamarins had intrahepatocellular Perls' iron-positive pigment diffusely throughout the lobule with a small amount of Fontana method-positive pigment. Ultrastructurally, hepatocytes from a hyperbilirubinemic tamarin contained pleomorphic electron-dense structures within lysosomes. Transport studies demonstrated secretion of fluorescein isothiocyanate-labeled glycocholic acid, a fluorescent bile acid analog, into bile canaliculi and no secretion of carboxydichlorofluorescein diacetate, a non-bile acid organic anion, by liver from a hyperbilirubinemic tamarin. In contrast, control liver secreted carboxydichlorofluorescein diacetate readily into bile canaliculi. The clinicopathologic presentation of this syndrome in golden lion tamarins is similar to that described for Dubin-Johnson syndrome of human beings.

Animals↗

Hormonal characteristics of free-ranging female lions (Panthera leo) of the Serengeti Plains and Ngorongoro Crater.

Pituitary responses to gonadotrophin-releasing hormone (GnRH) and prolactin and steroid secretory profiles were examined in two populations of adult, female lions in the Serengeti (one outbred in the Serengeti Plains and one inbred in the Ngorongoro Crater) to determine whether reductions in genetic variability adversely affected endocrine function. GnRH-induced gonadotrophin secretion was also examined after adrenocorticotrophic hormone (ACTH) treatment to determine whether acute increases in serum cortisol altered pituitary function. Anaesthetized lions were administered (i) saline i.v. after 10 and 100 min of blood sampling, (ii) saline at 10 min and GnRH (1 micrograms kg-1 body weight) after 100 min; or (iii) ACTH (3 micrograms kg-1) at 10 min and GnRH after 100 min of sampling. Basal serum cortisol and basal and GnRH-induced gonadotrophin secretion were similar (P > 0.05) between females of the Ngorongoro Crater and Serengeti Plains. After ACTH, serum cortisol increased two- to threefold over baseline values and the response was unaffected (P > 0.05) by location. ACTH-induced increases in serum cortisol had no effect on subsequent basal or GnRH-stimulated luteinizing hormone (LH) or follicle-stimulating hormone (FSH) secretion. Overall mean serum progesterone concentrations ranged from 0.2 to 5.4 ng ml-1 with the exception of four females (two in the Serengeti and two in the Crater; progesterone range, 18.4-46.5 ng ml-1) that were presumed pregnant (three of these females were observed nursing cubs several weeks later).(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗

Circannual inter-relationships among reproductive hormones, gross morphometry, behaviour, ejaculate characteristics and testicular histology in Eld's deer stags (Cervus eldi thamin).

Blood samples, morphometric measurements and behavioural data were collected weekly for 52 weeks from six adult Eld's deer stags exposed to natural fluctuations in photoperiod (38 degrees N latitude). Mean (+/- SEM) serum LH concentrations reached peak values in the autumn (October), three months before FSH and testosterone concentrations reached peak values in early winter (January). Prolactin concentrations were inversely related (r = -0.733, P < 0.001) to LH and directly related to daylength, and maximal concentrations were observed during mid-summer (July) and minimal concentrations during early winter (January). The temporal pattern of circulating inhibin was positively correlated with FSH (r = 0.88, P < 0.001), but lagged behind the seasonal FSH increase by 1-3 weeks. Antler length, body weight and chest girth were maximal during pre-rut (December-January). Maximal scrotal circumference and combined testes volume were observed in mid-winter (February), whereas peak neck girth and behavioural aggression occurred 1-3 months later (March-May). On the basis of quarterly electroejaculation results, motile spermatozoa were produced in all seasons. However, the greatest number of motile spermatozoa per ejaculate was observed during the winter and spring, whereas the highest incidence of sperm pleiomorphisms (> 80%) was detected in the autumn. Histological assessments of the regressed testis (July) revealed fewer germ cells undergoing spermatogenesis and an increased incidence of degenerating and abnormal cell types. In summary, Eld's deer exhibit a circannual hypothalamic-pituitary-gonadal cycle with onset of pituitary activation occurring during the autumn and winter, whereas gonadal activity peaks during the winter and spring as daylengths are increasing. Marked circannual variations in circulating prolactin suggest that Eld's deer may use photoperiodic cues to modulate seasonal fertility; however, the existence of an endogenous seasonal rhythm operating independently of photoperiod cannot be excluded.

Animals↗

Successful intrauterine insemination of Eld's deer (Cervus eldi thamin) with frozen-thawed spermatozoa.

This study tested the efficacy of assisted reproduction (synchronization of oestrus and intrauterine artificial insemination (AI)) in contributing to the captive propagation of an endangered species, the Eld's deer (Cervus eldi thamin). Semen was collected from males preselected on the basis of under-represented genotype. Motility of spermatozoa after thawing from ejaculates diluted with BF5F extender (8% glycerol), frozen on dry ice in 0.5 ml straws and stored in liquid nitrogen was 60-70%. Intravaginal progesterone-releasing devices (controlled internal drug release, CIDR-type G) were inserted into 20 adult Eld's deer hinds for 14 days. In all hinds, semen (7.5-10 x 10(6) motile spermatozoa per uterine horn) was deposited by laparoscopy performed 70 h after removal of the CIDR device. Ovarian activity, before and after AI, was monitored by analysing pregnanediol-3 alpha-glucuronide (PdG) concentrations in voided urine collected three to seven times per week. During the period of CIDR device insertion, urinary PdG profiles were equal to, or above, normal luteal phase concentrations in all hinds. Within 48 h of device withdrawal, PdG concentrations returned to baseline values in 17 of the 20 females, and the onset of behavioural oestrus occurred at this time in 12 hinds. On the basis of sustained increases in urinary PdG, 9 of the 20 hinds were diagnosed as pregnant by 90 days after AI, all of which delivered offspring after a mean gestation of 241.1 days (range, 235-245). Seven singletons (two females, five males) were born alive and survived, and one singleton and one set of twins were stillborn (three females).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Effects of GnRH analogues on pituitary-testicular function in free-ranging African elephants (Loxodonta africana).

We tested the ability of several GnRH analogues to suppress pituitary-testicular activity and potentially musth in free-ranging African elephants (Loxodonta africana). In Study 1, adult bulls were given 4 or 12 mg GnRH antagonist (Detirelix) or saline i.m. on day 0 (n = 3 bulls per treatment). Animals were then recaptured on day 2 (about 48 h later) and given 300 micrograms GnRH i.v. to assess the ability of the antagonist to block pituitary activity. Detirelix reduced (P < 0.05) basal concentrations of serum LH and testosterone on day 2 compared with day 0, with no effect of dose. Similarly, LH and testosterone release induced by GnRH were also reduced (P < 0.05) in the Detirelix-treated bulls (50-70% reduction in peak concentrations). In Study 2, elephants were given 30 mg of a structurally similar GnRH antagonist (103-201-40; n = 6), 22.5 mg of a long-acting GnRH agonist (Lupron Depot; n = 4) or D-mannitol carrier (n = 4) i.m. on day 0. All bulls were recaptured and given GnRH on day 2 (103-201-40 treatment) or on days 2 and 20 (Lupron Depot treatment) after the initial injection. In contrast to Detirelix, 103-201-40 did not inhibit basal or GnRH-induced LH or testosterone secretion. Pituitary-testicular responses to Lupron Depot were initially stimulatory, as evidenced by increased (P < 0.05) LH and testosterone secretion on days 0 and 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Africa↗

Correlation of sperm viability with gamete interaction and fertilization in vitro in the cheetah (Acinonyx jubatus).

Sperm-oocyte interaction in vitro was studied in the cheetah, a species known to produce poor quality ejaculates and to experience low rates of fertility. Twelve female cheetahs were injected (i.m.) with eCG followed by hCG 84 h later. Twenty-four to 26 h post hCG, each was subjected to laparoscopic oocyte aspiration. A sperm motility index (SMI) was calculated for each of 9 cheetah sperm donors that produced ejaculates averaging 41.3 +/- 22.9 x 10(6) motile sperm and 28.4 +/- 4.9% structurally normal sperm. Each ejaculate was used to inseminate cheetah oocytes from 1 or 2 females and salt-stored, domestic cat oocytes. The presence of ovarian follicles (greater than or equal to 1.5 mm in diameter) showed that all females responded to exogenous gonadotropins (range, 11-35 follicles/female). A total of 277 cheetah oocytes was collected from 292 follicles (94.9% recovery; 23.1 +/- 2.2 oocytes/female). Of these, 250 (90.3%) qualified as mature and 27 (9.7%) as degenerate. Of the 214 mature oocytes inseminated, 56 (26.2%) were fertilized, and 37 (17.3%) cleaved to the 2-cell stage in vitro; but the incidence of in vitro fertilization (IVF) varied from 0 to 73.3% (p less than 0.001) among individual males. When oocytes from individual cheetahs (n = 5) were separated into two groups and inseminated with sperm from a male with an SMI greater than 0 after 6 h coincubation versus an SMI = 0 at this time, the mean fertilization rates were 28/44 (63.6%) and 0/37 (0%), respectively (p less than 0.05). Of the 117 domestic cat oocytes coincubated with cheetah sperm, 96.6% contained 1 or more cheetah sperm in the outer half of the zona pellucida (ZP). Although the mean number of cheetah sperm penetrating the outer ZP of the cat oocyte was similar (p greater than 0.05) among all males, there was a positive correlation between the number of sperm reaching the inner half of the ZP and fertilization rate in vitro (r = 0.82; p less than 0.05). Compared to IVF efficiency in the domestic cat and tiger as reported in earlier studies, IVF efficiency in the cheetah is low. Because oocytes from 11 of 12 cheetahs were fertilized in vitro, there is no evidence that the female gamete is incompetent. Although sperm pleiomorphisms may contribute to poor reproductive performance, examination of the data on the basis of individual sperm donors reveals that effective gamete interaction in the cheetah is dictated, in part, by sperm motility.

Animals↗

Correct intranuclear localization of herpes simplex virus DNA polymerase requires the viral ICP8 DNA-binding protein.

We used indirect immunofluorescence to examine the factors determining the intranuclear location of herpes simplex virus (HSV) DNA polymerase (Pol) in infected cells. In the absence of viral DNA replication, HSV Pol colocalized with the HSV DNA-binding protein ICP8 in nuclear framework-associated structures called prereplicative sites. In the presence of viral DNA replication, HSV Pol colocalized with ICP8 in globular intranuclear structures called replication compartments. In cells infected with mutant viruses encoding defective ICP8 molecules, Pol localized within the cell nucleus but showed a general diffuse intranuclear distribution. In uninfected cells transfected with a plasmid expressing Pol, Pol similarly showed a diffuse intranuclear distribution. Therefore, Pol can localize to the cell nucleus without other viral proteins, but functional ICP8 is required for Pol to localize to prereplicative sites. In cells infected with mutant viruses encoding defective Pol molecules, ICP8 localized to prereplicative sites. Thus, Pol or the portions of Pol not expressed by the mutant viruses are not essential for the formation of prereplicative sites or the localization of ICP8 to these structures. These results demonstrate that a specific nuclear protein can influence the intranuclear location of another nuclear protein.

Animals↗

Developmental changes in pituitary-gonadal function in free-ranging lions (Panthera leo leo) of the Serengeti Plains and Ngorongoro Crater.

Pituitary-gonadal function was examined in male lions free-ranging in the Serengeti Plains or geographically isolated in the Ngorongoro Crater of Tanzania. Lions were classified by age as adult (6.1-9.8 years), young adult (3.3-4.5 years) or prepubertal (1.4-1.6 years, Serengeti Plains only). Each animal was anaesthetized and then bled at 5-min intervals for 100 min before and 140 min after i.v. administration of saline or GnRH (1 micrograms/kg body weight). Basal serum LH and FSH concentrations were similar (P greater than 0.05) among age classes and between locations. In Serengeti Plains lions, net LH peak concentrations after GnRH were approximately 35% greater (P less than 0.05) in prepubertal than in either adult or young adult animals. GnRH-stimulated LH release was similar (P greater than 0.05) between adult and young adult lions, and these responses were similar (P greater than 0.05) to those measured in Ngorongoro Crater lions. Basal and GnRH-stimulated testosterone secretion was higher (P less than 0.05) in adult than in young adult lions and lowest (P less than 0.05) in prepubertal lions. Age-class differences in testosterone production were related directly to the concentrations of LH receptors in the testis (P less than 0.05). Basal and GnRH-stimulated testosterone secretion and gonadotrophin receptor concentrations within age classes were similar (P greater than 0.05) between lions of the Serengeti Plains and Ngorongoro Crater. Lower motility and higher percentages of structurally abnormal spermatozoa were observed in electroejaculates of young adult compared to adult Serengeti Plains males (P less than 0.05) and were associated with decreased steroidogenic activity. In contrast, there were no age-related differences in ejaculate characteristics of Ngorongoro Crater lions. Seminal quality in the Crater population was poor in adult and young adult animals and was unrelated to alterations in pituitary or testicular function. In summary, only seminal quality in adult male lions was affected by location, whereas age significantly affected both basal and GnRH-stimulated testosterone secretion and seminal quality (Serengeti Plains only) in sexually mature males. The striking seminal/endocrine differences among pride (breeding) males of different ages raises questions about the impact of age on individual reproductive performance in this species.

Aging↗

Impact of season on seminal characteristics and endocrine status of adult free-ranging African buffalo (Syncerus caffer).

Pituitary, gonadal and adrenal activity were compared in free-living, adult African buffalo bulls during the breeding and nonbreeding seasons. Frequent blood samples were collected for 2 h from anaesthetized bulls treated intravenously with saline, gonadotrophin-releasing hormone (GnRH, 200 micrograms), human chorionic gonadotrophin (hCG, 10,000 i.u.) or adrenocorticotrophic hormone (ACTH, 1.5 mg). Electroejaculates also were collected from anaesthetized bulls during the breeding and nonbreeding seasons. Pretreatment testosterone concentrations among bulls varied more during the breeding (0.17-23.0 ng/ml) than the nonbreeding (0.15-2.21 ng/ml) season. The variation within the breeding season was attributed to 8 of 25 bulls producing higher (P less than 0.05) serum testosterone (High-T; 16.28 +/- 2.03 ng/ml) and testicular LH receptor (1.53 +/- 0.22 fmol/mg testis) concentrations compared with their seasonal counterparts (Low-T; 0.95 +/- 0.26 ng/ml; 0.38 +/- 0.04 fmol/mg) or with all bulls during the nonbreeding season (0.90 +/- 0.27 ng/ml; 0.31 +/- 0.04 fmol/mg). The magnitude of GnRH- and hCG-induced increases in serum testosterone was similar (P greater than 0.05) between Low-T bulls and bulls during the nonbreeding season. In the High-T animals treated with GnRH or hCG, serum testosterone did not increase, suggesting that secretion was already maximal. Peak serum LH concentrations after GnRH were greater (P less than 0.05) in bulls during the nonbreeding than the breeding season; FSH responses were similar (P greater than 0.05). ACTH treatment did not increase serum cortisol concentrations above the 2-fold increase measured in bulls treated with saline, hCG and GnRH (P greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Semen characteristics in free-living koalas (Phascolarctos cinereus).

Spermic electroejaculates (range in motile sperm/ejaculate, 0.50-122.9 x 10(6); mean +/- s.e.m., 38.6 +/- 4.9) were recovered from 47 of 48 adult koalas captured from 3 wild populations in Australia. Semen was characterized by (i) a high density of globular bodies, which prevented the estimation of sperm motility without dilution; (ii) a brownish colour; and (iii) an acidic pH. Spermatozoa were categorized on the basis of 10 head forms, most cells being a curved or hooked shape. The koala populations differed in sperm concentration and motility ratings, but not in testes size, testosterone production or proportions of spermatozoa with various head shapes. These data confirm that free-living koalas normally produce spermatozoa with a high incidence of structural heterogeneity almost solely confined to the head region; and demonstrate the utility and safety of conventional gamete and endocrine studies, approaches which will be useful for determining the impact of genetic isolation and venereal disease on species fertility.

Animals↗

Comparative semen cryopreservation in ferrets (Mustela putorius furo) and pregnancies after laparoscopic intrauterine insemination with frozen-thawed spermatozoa.

A study was conducted to determine an optimum technique for semen cryopreservation and the biological competence of frozen-thawed ferret spermatozoa. Fifty-two fresh electroejaculates from 4 males were evaluated for sperm percentage motility, forward progressive motility, motility index (SMI) and acrosomal integrity. To determine the optimum temperature for maintaining sperm motility in vitro and the influence of glycerol on sperm motility, seminal aliquants were diluted in TEST diluent (containing either 0 or 4% glycerol) and maintained at 25 degrees or 37 degrees C. For cryopreservation, semen was diluted in each of 3 cryodiluents (TEST, PDV, BF5F), cooled for 30 min at 5 degrees C and pelleted on solid CO2 or frozen in 0.25 ml straws (20 degrees C/min to -100 degrees C). Following thawing, SMI and acrosomal integrity were determined. Ten females with maximum vulval swelling were given 90 i.u. human chorionic gonadotrophin and laparoscopically inseminated in utero with spermatozoa previously frozen using the optimum diluent and freeze-thaw method. The maintenance temperature of 25 degrees C was superior (P less than 0.05) to 37 degrees C for sustaining sperm motility, and glycerol did not influence (P greater than 0.05) motility for up to 11 h of culture. After thawing, motile spermatozoa were recovered in all treatment groups, but sperm motility and normal acrosomal ratings were highest using the PDV diluent, the pelleting method and thawing at 37 degrees C (P less than 0.05). Seven of the 10 ferrets (70%) inseminated with spermatozoa frozen by this approach became pregnant and produced 31 kits (mean litter size 4.4; range 1-9 kits).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Seasonal variation in pituitary-gonadal function in free-ranging impala (Aepyceros melampus).

Blood, testicular biopsies and electroejaculates were collected from adult male impala, free-ranging in the Kruger National Park (Republic of South Africa), during the breeding (rut; April-May) and nonbreeding (September-October) seasons. Blood samples were collected at 5-min intervals for 120 min from anaesthetized males (n = 7 impala/group) treated intravenously with saline, gonadotrophin-releasing hormone (GnRH: 1 microgram/kg body weight) or human chorionic gonadotrophin (hCG: 10 or 30 iu/kg). Semen was collected from six more animals during the breeding season and 12 animals during the nonbreeding season using a standardized electroejaculation protocol. Ejaculates obtained during the nonbreeding season were of inferior quality to those collected during the breeding season, and were characterized by lower sperm concentrations, poorer sperm motility and more morphologically abnormal sperm forms. Within season, there were no differences in testosterone secretion between the two hCG doses, and these responses were similar to those observed after GnRH, but during the rut, testosterone secretion stimulated by both GnRH and hCG was approximately nine times greater than during the nonbreeding season. This seasonal increase in testosterone production was associated with a doubling in testicular volume and concentrations of luteinizing hormone (LH) receptors. Although concentrations of testicular follicle-stimulating hormone (FSH) receptors were similar between seasons, receptor content increased during rut as a result of increased testicular volume. In contrast to testosterone secretion, basal LH and FSH secretions were unaffected by season and GnRH-induced gonadotrophin secretion was reduced during rut.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Antibodies with high affinity for spiroperidol--II. Cross reactivity with iodobenzamide and domperidone.

Three radioligands, 3H-spiroperidol (3H-SPD), 3H-domperidone (3H-DOMP) and 125I-iodobenzamide (125I-IBZM), were used to investigate the antibody response to two haptens, aminospiroperidol (NH2SPD) and N-aminophenethylspiroperidol (NAPS). Although structurally different, these three radioligands each bind with high affinity to the D2 dopamine receptor. Antibodies with high affinity for 3H-SPD were elicited in rabbits following immunization with the hapten NH2SPD covalently linked to keyhole limpet hemocyanin (KLH). In addition, antibodies in the rabbit anti-NH2SPD antisera bound 125I-IBZM or 3H-DOMP. Rabbit anti-NH2SPD antibodies that bound 125I-IBZM or 3H-DOMP were found to have higher affinity for IBZM or DOMP, respectively, than for SPD. The binding properties of the anti-NH2SPD antibodies that bound 3H-SPD, 125I-IBZM and 3H-DOMP were characterized using a panel of competitive inhibitors and each radioligand appeared to bind to a distinct subpopulation of anti-NH2SPD antibodies. BALB/c mice were immunized with NH2SPD-KLH or NAPS-KLH. A population of antibodies that bound 3H-SPD and a population of antibodies that bound 3H-DOMP were detected. The population of antibodies that bound 3H-DOMP was found to be heteroclitic for DOMP, since DOMP was a more effective competitive inhibitor than SPD. Binding sites for 125I-IBZM were not detected in either the anti-NH2SPD or the anti-NAPS BALB/c antisera. However, two anti-NAPS monoclonal antibodies, N6-24 and N6-29, that bind 3H-SPD with high affinity (Kd = 10(-9) M), were also found to bind IBZM (Ki = 2 x 10(-7) M) and DOMP (Ki = 2 x 10(-6) M). Although anti-NH2SPD and anti-NAPS antibodies were identified that appeared to bind 3H-SPD, 3H-DOMP or 125I-IBZM with high affinity, none of the populations of polyclonal antibodies or monoclonal antibodies bound all three ligands with high affinity.

Animals↗

Dissociative anaesthesia in free-ranging male koalas and selected marsupials in captivity.

Forty seven free-ranging, adult, male koalas were captured and administered an intramuscular injection of the dissociative anaesthetic, Telazol (tiletamine HCl plus zolazepam HCl), at dose rates of 5.0 to 7.7 mg/kg body weight. Anaesthesia induction was rapid and smooth and resulted in a surgical plane of anaesthesia lasting 30 to 45 min. There was no depression of heart rate or respiration. Mild salivation occurred in most animals, but was not a problem because the swallowing reflex was retained. There was no mortality or morbidity and the anaesthesia level was sufficient to allow electroejaculation and multiple blood sampling with no apparent animal discomfort. For 10 of 19 males in which anaesthesia was required for a 90 min protocol, a supplementary Telazol injection (average, 2.5 mg/kg) was necessary. All koalas recovered completely within 3 to 4 h of the initial injection. The results suggest that the optimal Telazol dosage for the adult male koala is 7.0 mg/kg body weight. The retrospective analysis of 259 anaesthesia records involving 14 species indicated that Telazol was equally effective and safe in other captive marsupials.

Anesthesia↗

Prevalence and implications of feline coronavirus infections of captive and free-ranging cheetahs (Acinonyx jubatus).

The extent and progression of exposure to feline infectious peritonitis (FIP) virus in the cheetah, Acinonyx jubatus, was monitored by a world-wide serological survey with indirect fluorescent antibody titers to coronavirus. The indirect fluorescent antibody assay was validated by Western blots, which showed that all indirect fluorescent antibody-positive cheetah sera detected both domestic cat and cheetah coronavirus structural proteins. There was a poor correlation between indirect fluorescent antibody results and the presence of coronaviruslike particles in cheetah feces, suggesting that electron microscopic detection of shed particles may not be an easily interpreted diagnostic parameter for FIP disease. Low, but verifiable (by Western blots [immunoblots]) antibody titers against coronavirus were detected in eight free-ranging cheetahs from east Africa as well as from captive cheetahs throughout the world. Of 20 North American cheetah facilities screened, 9 had cheetahs with measurable antibodies to feline coronavirus. Five facilities showed patterns of an ongoing epizootic. Retrospective FIP virus titers of an FIP outbreak in a cheetah-breeding facility in Oregon were monitored over a 5-year period and are interpreted here in terms of clinical disease progression. During that outbreak the morbidity was over 90% and the mortality was 60%, far greater than any previously reported epizootic of FIP in any cat species. Age of infection was a significant risk factor in this epizootic, with infants (less than 3 months old) displaying significantly higher risk for mortality than subadults or adults. Based upon these observations, empirical generalizations are drawn which address epidemiologic concerns for cheetahs in the context of this lethal infectious agent.

Acinonyx↗

Familial goiter in bongo antelope (Tragelaphus eurycerus).

Congenital defects in thyroglobulin (Tg) synthesis in animals have proven to be useful models for the study of Tg synthesis and regulation. Defects in Tg synthesis have been well described in Afrikander cattle, Australia Merino sheep, and goats in The Netherlands. This report describes a study of goiter in a nondomesticated bovine species, bongo antelope (Tragelaphus eurycerus), an African bovid. Three animals housed at the National Zoological Park, Washington, D.C. were studied; two had visible goiters, and a third bongo had microscopic evidence of goiter. Tg extracted from thyroid glands or thyroid colloid from these animals had a high mol wt component that was greater than 220K daltons and differed in apparent mol wt from 19S Tg from domestic cattle. Thyroid extracts also had thyroid albumin; albumin was more than half the total protein in colloid extract. The animals with goiter were euthyroid according to their circulating levels of thyroid hormones.

Animals↗

Monitoring ovarian function and pregnancy in Eld's deer (Cervus eldi thamin) by evaluating urinary steroid metabolite excretion.

Direct radioimmunoassays (RIA) for urinary oestrone conjugates and pregnanediol-3 alpha-glucuronide (PdG) were used to study ovarian activity patterns and pregnancy in Eld's deer. In 2 does, urinary metabolite patterns were compared to temporal patterns of plasma LH, oestradiol-17 beta and progesterone. Preovulatory LH peaks occurred coincident with behavioural oestrus, and plasma progesterone secretion paralleled PdG excretion. Although plasma oestradiol-17 beta levels fluctuated between 5 and 10 pg/ml throughout the oestrous cycle, no preovulatory oestrogen surge was observed. Based on PdG excretion, non-conception oestrous cycles averaged 21.5 +/- 2.1 days (+/- s.e.m., n = 65); however, 2 of 13 does exhibited prolonged oestrous cycles (30.1 +/- 4.4 days; range 14-62 days, n = 14) characterized by sustained PdG excretion. Excluding these 2 females, the mean oestrous cycle was 18.5 +/- 0.3 days (range 14-23 days, n = 51). Behavioural oestrus (12-24 h duration) was observed in 42 of 65 cycles (64.6%), and always corresponded with intercyclic troughs in PdG excretion (2-5 days duration). Mean gestation duration (n = 10) was 33.5 +/- 0.4 weeks. PdG concentrations increased (P less than 0.05) by Week -32 (3rd week of gestation), plateaued between Weeks -31 and -25, increased (P less than 0.05) markedly by Week -22 and then rose steadily until parturition, declining (P less than 0.05) rapidly thereafter. Mean excretion of oestrone conjugates remained low until Week -30, increased (P less than 0.05) steadily to Week -24 (P less than 0.05) and then returned to baseline by Week -17. Increased (P less than 0.05) oestrone conjugates concentrations were detected again by Week -4 followed by a rapid increase to peak pregnancy levels by Week -1, declining (P less than 0.05) precipitously after parturition. The results confirm that the Eld's deer is seasonally polyoestrous with onset (January-March) and cessation (August-October) of regular, cyclic ovarian activity coinciding with increasing and decreasing daylengths, respectively. Urinary PdG excretion accurately reflects cyclic ovarian activity and markedly elevated concentrations of this metabolite provide an accurate index of pregnancy. The simultaneous monitoring of oestrone conjugates appears useful for estimating the stage of pregnancy and predicting parturition onset.

Animals↗