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Biomedical subjects

M Bush

Publications and source records attributed to M Bush.

At least 37 records · Page 2Linked to original sources
PubMed1998

Abdominal lipomatosis attributed to tall fescue toxicosis in deer.

Five adult female Eld's deer died acutely or were euthanatized because of clinical signs including anorexia, signs of depression, and uremia. On necropsy, these deer had large masses of necrotic abdominal fat constricting the ureters, causing hydroureter and hydronephrosis. The herd from which these deer originated was maintained on pastures consisting primarily of tall fescue, samples from which were subsequently confirmed to be infected with an endophytic fungus that is known to cause similar lesions in cattle. A retrospective study of deaths in this herd revealed a sharp increase in incidence of abdominal lipomatosis since 1994. Physical examinations on the herd revealed > 90% of females to be affected. Endophyte-infected tall fescue forage was concluded to be a major factor in the development of lipomatosis in these deer. Other contributing factors were considered. Lesions caused by endophyte-infected fescue can be severe, and this disease can develop in nondomestic species.

Acremonium↗
PubMed1998

Patellar tendon rupture in five deer.

Acute unilateral or bilateral rupture of the patellar tendon was diagnosed in 5 aged obese female Pere David's deer housed at a zoological park. Rupture occurred after an episode of sudden exertion in 4 of 5 deer. Fragmentation, degeneration, necrosis, and mineralization of ruptured patellar tendon fibers were found on histologic examination. Similar changes were often seen in intact contralateral tendons that did not have gross lesions. Patellar tendon rupture in humans is associated with concurrent systemic disease, such as systemic lupus erythematosus, rheumatoid arthritis, or chronic renal failure. Without evidence of underlying systemic disease, spontaneous patellar tendon rupture in deer can be considered a sequela to age-related tendinous degeneration compounded by sudden exertion and chronic overload attributable to obesity.

Aging↗
PubMed1998

Fundamental cryobiology of selected African mammalian spermatozoa and its role in biodiversity preservation through the development of genome resource banking.

Fundamental cryobiological characteristics of spermatozoa from threatened or endangered species must be determined for successful cryopreservation techniques to be established. In this study, spermatozoa from four diverse species, impala (Aepyceros melampus), wart hog (Phacochoerus aethiopicus), elephant (Loxodonta africana), and lion (Panthera leo), were collected by electroejaculation or epididymal aspiration. Spermatozoal plasma membrane permeability to water (hydraulic conductivity, Lp) and the osmotically inactive fraction of the sperm cell (Vb) were determined from each species. Changes in cell volume were measured over time using an electronic particle counter. A Kedem-Katchalsky membrane transport model was used to theoretically characterize the data to determine Lp and Vb for each species. In addition to determining plasma membrane characteristics, spermatozoa were also studied to determine their sensitivity to low temperatures and to permeating cryoprotectant solutes. Cells maintained at room temperature (20-22 degrees C) were slowly or rapidly exposed to cold temperatures (1-4 degrees C), and percent motility was estimated to determine the sensitivity of the cells to cooling. Spermatozoa were also in media containing 1 M glycerol, dimethyl sulfoxide or ethylene glycol, and percent motility was measured at 15, 30 and 60 min intervals to determine the sensitivity of the cells to the cryoprotectant agent over time. Results indicate that sperm motility is significantly effected by decreased temperatures and the presence of cryoprotectant agents.

Animals↗
PubMed1998

Antral follicles develop in xenografted cryopreserved African elephant (Loxodonta africana) ovarian tissue.

The preservation of germ plasm from endangered species could augment captive breeding programs aimed at maintaining genetic diversity. Mammalian female germ plasm (oocytes) is extremely difficult to collect and cryopreserve; however, a promising alternative is the cryopreservation of ovarian tissue. In the present study, athymic nude (nu/nu) Balb/C mice were used to evaluate in vivo viability of cryopreserved ovarian tissue from Institute of Cancer Research genotype (ICR) mice or elephants. Female mice were ovariectomized prior to transplant of cryopreserved-thawed ovarian tissue from ICR mice (n=4) or elephants (n=6). Control mice were sham operated (n=4) or ovariectomized (n=5). Transplants were in the ovarian bursa, enabling in vivo ovulation and pregnancies from allografts. Vaginal cytology was monitored daily, and the intervals between and duration of epithelial cells present in smears were evaluated. Appearance of epithelial cells in sham-operated and allografted mice were at intervals of 4.3+/-0.6 and 3.3+/-0.5 days, lasting for 1.4+/-0.1 and 1.6+/-0.2 days, respectively. Sporadic incidence of epithelial cells in ovariectomized animals occurred at longer intervals (8.6+/-3.8 days). Females with xenografted elephant ovarian tissue demonstrated epithelial cells in vaginal smears at intervals of 4.5+/-1.0 days, for 2.5+/-0.5 days duration, which was significantly longer than the other groups (P < 0.05). Histological evaluation of tissues at the time of epithelial cells in smears demonstrated well-developed antral follicles, although oocytes were of poor morphological appearance or only cumulus-like complexes were seen. The nude mouse model is effective for assessing cryopreserved ovarian tissue xenograft function which can support the development of antral follicles.

Animals↗
PubMed1998

Primary Mycobacterium avium complex infections correlate with lowered cellular immune reactivity in Matschie's tree kangaroos (Dendrolagus matschiei).

The National Zoological Park has maintained a breeding colony of Matschie's tree kangaroos (Dendrolagus matschiei) since 1975 with a documented history and continued prevalence of Mycobacterium avium complex (MAC) infections. No evidence of immunosuppressive retrovirus infections or loss of heterozygosity that may have led to an immune dysfunction in these animals was found. Isolates of MAC organisms from affected tree kangaroos and from their environment had no common restriction fragment DNA types. Cellular immune reactivity in apparently healthy tree kangaroos was 3- to 6-fold lower than in humans and other marsupial and eutherian mammals, as determined by lymphocyte proliferative assays. Thus, while MAC infections are typically opportunistic in humans and other mammals, tree kangaroos commonly develop primary progressive disease with MAC from random sources. Comparative information derived from this study should benefit both the endangered tree kangaroo and humans with immunosuppressive disorders that lead to mycobacterial infections.

Animals↗
PubMed1998

Heterologous in vitro fertilization and sperm capacitation in an endangered African antelope, the scimitar-horned oryx (Oryx dammah).

Scimitar-horned oryx sperm function was studied using protocols developed for domestic cattle. Objectives were to assess sperm 1) viability and motility in vitro over time, 2) capacitation in heparin- or calcium-supplemented medium, and 3) function in an in vitro fertilization system using heterologous (domestic cow) oocytes. Seminal aliquots were washed, and sperm were resuspended in 1) Talp with 5% fetal calf serum (TALP), 2) TALP + 10 microM heparin, 3) TALP + 20 microM heparin, and 4) TALP + 10 mM CaCl. At 0, 3, and 6 h, aliquots were evaluated for sperm motility, viability (using Hoechst 33258), and ability to acrosome-react when exposed to lysophosphatidylcholine (LC). Sperm function was assessed by evaluating fertilization and embryo development after coculture of in vitro-matured domestic cow oocytes with oryx sperm. Overall mean percentages of motile and viable sperm remained high at 6 h (> 60% and > 70%, respectively). Fewer (p < 0.05) sperm incubated in TALP + 10 microM heparin for 6 h contained intact acrosomes after exposure to LC, but there were no differences between LC and control samples after incubation in TALP without heparin. LC-treated sperm in TALP + 10 mM CaCl contained fewer (p < 0.05) intact acrosomes at 3 and 6 h (52.6% and 31.2%, respectively) than paired controls (83.6% and 70.0%, respectively). Oryx sperm from all males were capable of fertilizing cow oocytes (range 17 of 26 [65.4%] to 25 of 26 [96.2%]). Of the 55 2-cell embryos produced, 34 (61.8%) developed to > or = 8 cells. Of the 24 uncleaved oocytes, 7 (29.2%) were polyspermic. These data demonstrate that processed sperm from the endangered scimitar-horned oryx remain vigorous in vitro for at least 6 h. Capacitation can be induced using cattle sperm-processing techniques, with sperm appearing most responsive to elevated CaCl concentrations. Most interesting was the successful production and development of hybrid embryos after coincubation of oryx sperm with cow oocytes, suggesting that the two bovid species have similar fertilization mechanisms.

Acrosome↗
PubMed1997

Interpersonal guilt: the development of a new measure.

We describe the development of a new measure to assess guilt related to concern about harming others. The two versions of the Interpersonal Guilt Questionnaire, a 45-item and 67-item version, include theoretically-based and clinically relevant categories of guilt: survivor guilt, separation/disloyalty guilt, omnipotent responsibility guilt, and self-hate guilt. Preliminary reliability and validity studies for both versions are presented, based on clinical and nonclinical samples of subjects. Subscales on both versions show good internal consistency; however, the second version, which expanded on the first, is more psychometrically sound overall. Both versions demonstrated predicted correlations with previously published measures of guilt and related affects, such as shame and depression, and with attributional style. Differences between clinical and nonclinical samples are reported and the relevance of survivor guilt and shame to psychopathology is noted.

Adult↗
PubMed1997

Prevalence of endometriosis in adolescent girls with chronic pelvic pain not responding to conventional therapy.

STUDY OBJECTIVE: To evaluate adolescent girls with chronic pelvic pain not responding to conventional medical therapy, using advances in operative laparoscopy to determine endometriosis prevalence, clinical stage, and type of lesion. DESIGN: A descriptive retrospective study of subjects who (1) were referred for the evaluation of chronic pelvic pain, (2) did not respond to a nonsteroidal anti-inflammatory drug and an oral contraceptive pill, and (3) underwent a laparoscopy to determine the etiology of the pelvic pain. SETTING: Patients referred to a surgical gynecologist in a pediatric/adolescent gynecology and reproductive endocrine academic practice. PARTICIPANTS: All patients younger than 22 years of age with chronic pelvic pain. INTERVENTION: Operative laparoscopy to determine the etiology of the chronic pelvic pain. MAIN OUTCOME MEASURES: Operative laparoscopy results including stage and description of endometriosis. RESULTS: More than two thirds of the study population (69.6%) was found to have endometriosis. All subjects had either stage I or II as determined by the American Fertility Society's classification system. The nature of the pain in the 32 subjects with endometriosis was both acyclic and cyclic in 20 (62.5%), acyclic only in 9 (28.1%), and cyclic only in 3 (9.4%). Other presenting symptoms included gastrointestinal in 11 (34.3%), urinary in 4 (12.5%), and irregular menses in 3 (9.4%). CONCLUSIONS: Adolescents with chronic pelvic pain not responding to medical therapy have a high rate of endometriosis and should be referred to a gynecologist who is experienced with the subtle laparoscopic findings of atypical endometriosis to diagnose the etiology of the pelvic pain and initiate appropriate therapy.

Adolescent↗
PubMed1997

Zinc toxicosis in a Celebes ape (Macaca nigra) following ingestion of pennies.

An adult Celebes ape (Macaca nigra) was presented for a routine yearly evaluation. Abdominal radiographs revealed four radiodense metallic foreign objects resembling coins within the gastrointestinal tract. Hematologic abnormalities included a mild nonregenerative anemia and a mild leukocytosis, and the biochemical profile reflected renal dysfunction. Serum zinc levels were elevated. The animal was denied food for 24 hr in preparation for the endoscopic removal of the foreign objects. During this period, two partially eroded pennies were passed in the feces. Endoscopy was temporarily postponed, and the animal was offered food. Two days later a third penny was passed. When the fourth coin did not pass within the next 2 days, the animal was once again denied food, and the fourth coin was passed within 24 hr. Because of the temporal association between the fasting cycles and the passage of the coins, a causal relationship is suggested. Following the passage of all coins, serum zinc levels decreased, and hematologic and serum biochemical abnormalities improved. Six months later, all abnormalities had resolved.

Animals↗
PubMed1997

Cryptococcosis in tree shrews (Tupaia tana and Tupaia minor) and elephant shrews (Macroscelides proboscides).

Fungal infections due to Cryptococcus neoformans occurred in seven short-eared elephant shrews (Macroscelides proboscides), six large tree shrews (Tupaia tana), and five lesser tree shrews (Tupaia minor) at the National Zoological Park during a 30-mo period in 1991-1993. Clinical signs were absent or included weight loss, shivering, dyspnea, and/or neurologic disease. Definitive antemortem diagnostic techniques included tracheal lavage and serum cryptococcal antigen latex agglutination titers. Thirteen cases were diagnosed solely by postmortem examination. The source of infection for these animals was uncertain, but C. neoformans is commonly found in soil and other organic material. Two lesser tree shrews and one large tree shrew received antifungal therapy and converted to a negative serum cryptococcal antigen titer.

Animals↗
PubMed1996

Natural and induced ovarian synchrony in golden lion tamarins (Leontopithecus rosalia).

Ovarian cycle synchrony was assessed in spontaneously cycling female golden lion tamarins by monitoring longitudinal (16 mo) urinary steroid metabolite (estrone conjugates; pregnanediol-3 alpha-glucuronide, PdG) excretion in four pairs (n = 8) of females isolated from males. The overall mean ovarian cycle duration was 18.5 +/- 0.3 days (n = 136 cycles; mean range, 15.7-21.0 days), and there was no evidence of reproductive seasonality. Laparoscopic ovarian examinations confirmed that cyclic fluctuations in urinary steroid metabolite excretion were temporally associated with the formation and demise of corpora lutea. Evaluation of ovarian synchronization tested the null hypothesis that urinary hormone cycles were expressed randomly relative to those of cagemates or other females housed in separate cages but within close proximity. Natural ovarian synchrony (expressed as the mean difference in ovarian cycle onset) between cagemates (4.1 +/- 0.4 days) and among noncagemates (4.2 +/- 0.2 days) did not differ (p > 0.05) from a random ovarian cycle distribution. Two trials also were conducted to evaluate the efficacy of the prostaglandin (PG) F2 alpha analogue, cloprostenol, for artificially synchronizing ovarian cycles. Induced ovarian synchrony was not achieved with a single 0.8-microgram i.m. injection of cloprostenol. However, doubling the cloprostenol dose (1.6 micrograms) caused a rapid decrease in mean urinary PdG (p < 0.05) within 2 days, and synchronous ovulation was demonstrated by an increase (p < 0.01) in mean urinary PdG 10 days after cloprostenol administration. In summary, females housed in pairs, in the absence of males, exhibit spontaneous, year-round ovarian cycles with no evidence of among-female ovarian synchrony. Results also suggest that this New World primate has a reduced sensitivity to cloprostenol (compared to common marmosets) but that a single, midcycle cloprostenol injection of 1.6 micrograms effectively induces luteolysis and synchronous ovulation.

Animals↗
PubMed1996

Genetic diversity affects testicular morphology in free-ranging lions (Panthera leo) of the Serengeti Plains and Ngorongoro Crater.

Reduced genetic variability is known to adversely affect ejaculate quality in inbred lions (Panthera leo) physically isolated in the Ngorongoro Crater compared with outbred lions inhabiting the adjacent Serengeti Plains in East Africa. This study compared the histomorphology of testicular biopsies from these two lion populations. Ngorongoro Crater lions had fewer (P < 0.05) seminiferous tubules with spermiogenesis and fewer (P < 0.05) spermatids per seminiferous tubular cross-section than Serengeti Plains lions, although seminiferous tubular diameter did not differ (P > 0.05) between populations. Interstitial areas were greater (P < 0.05) in Crater than in Plains lions, but no qualitative differences were evident, suggesting that proportionately less testicular area was occupied by seminiferous tubules in Crater lions. None of the lions in either population had evidence of testicular degeneration. Overall results suggest that inbred Crater lions have reduced spermiogenesis and less total seminiferous tubular area per testis. These data further support the premise that genetic homogeneity compromises reproductive traits in free-living, male African lions.

Africa↗
PubMed1993

Prevalence of shigellosis and other enteric pathogens in a zoologic collection of primates.

An epidemiologic study of shigellosis was the preliminary step in the formulation of a plan for the control of devastating infectious diseases in nonhuman primates at the National Zoological Park. Data were collected from primate groups with enzootic shigellosis and included the following species: white-cheeked and siamong gibbons (Hylobates concolor and H syndactylies); lion-tailed, celebes, and Barbary macaques (Macaca silenus, M nigera, and M sylvanus); black and white colobus monkeys (Colobus guerzea); grey-cheeked mangabeys (Cerecocebus albigena); spider monkeys (Ateles susciceps robusuts); ruffed lemurs (Lemur varrigatus); lowland gorillas (Gorilla gorilla); and orangutans (pongo pygmaeus). Data included results of physical examination, proctoscopy with biopsy, fecal parasitologic and cytologic examinations, and bacteriologic culturing of swabbed specimens of rectum and gingiva. Repetitive fecal examinations were subsequently performed and included bacteriologic culturing of fecal specimens for enteropathogenic bacteria and parasites and cytologic examination of feces. Data were collected for a 1-year period from 82 primates, and 14 gibbons were studied intensively. White-cheeked and siamang gibbons shed Shigella flexneri sporadically, but persistently. All gibbons were affected with a mean point prevalence of 30.7% (range 0 to 71%). Shigella flexneri also was isolated from feces of lion-tailed macaques. Shigella sonnei was isolated from feces of grey-cheeked mangabeys, celebes macaques, and spider monkeys.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Clearance of Shigella flexneri carriers in a zoologic collection of primates.

In 1990, a high prevalence of Shigella flexneri was documented in the gibbon population at the National Zoological Park. The enzootic strain had been determined to be resistant to most antibiotics and had been responsible for animal deaths. Prevalence of Shigella spp was high in the entire primate population. To address the clinical problem, eradication was attempted by use of enrofloxacin. Facilities disinfection comprised a large part of Shigella clearance efforts. After the clearance protocol was completed gibbons, vs other primate species, were closely monitored for 16 months by subjecting their feces to bacteriologic culturing. The program was successful, with eradication of the problematic strain of S flexneri. However, 10 to 12 months after completion of treatments, S sonnei was isolated from feces of 3 animals living in the same housing facility.

Animals↗