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Biomedical subjects

G L Foley

Publications and source records attributed to G L Foley.

At least 19 recordsLinked to original sources
PubMed2005

Effects of feed restriction on fertility in female rats.

BACKGROUND: Feed restriction with its resultant body weight loss impacts the rodent estrous cycle; however, the manifestation of these changes in a regulatory study design has not been documented. This study reports the effects of feed restriction in the context of an FDA regulatory submission. METHODS: Adult female rats (n = 20/group; weighing approximately 200 g each) were provided rodent chow ad lib (control) or at 20, 15, 10, or 7.5 g/rat/day (g/day) during a 2-week pre-mating phase, throughout the mating phase, and up to gestation day (GD) 7. On GD 8, all animals were provided ad lib feed until necropsy on GD 14. Estrous cyclicity, mating, and fertility parameters were evaluated. RESULTS: Ad lib rats consumed approximately 20 and 28 g/day during the pre-mating and gestation phases, respectively. All measured fertility parameters in the 20 g/day group were similar to control values. In the 15 g/day group, body weight was reduced by 16% at 2 weeks, prolonged diestrus occurred, and fertility was compromised due to reductions in corpora lutea. Within 2 weeks, mean body weight in groups receiving < or = 10 g/day was reduced by > or = 29% compared to ad lib values, and overt changes in estrous cyclicity, mating, and fertility occurred. The 7.5 g/day group was not sustainable beyond the pre-mating phase. CONCLUSIONS: For this study type, feed intake at < or = 50% ad lib values (< or = 10 g/day) was inadequate due to the magnitude and rapidity of body weight effects. Estrous parameters appeared slightly more sensitive than functional measures, as body weight changes of approximately 16% appeared near the threshold of changing routinely calculated estrous cycle parameters and were later associated with reduced fertility. In general, body weight differences of 10-15% by themselves were not adverse to normal reproduction (20 g/day).

Animals↗
PubMed2001

Clinical implications of rhinoceros reproductive tract anatomy and histology.

Reproductive tracts or tissues from five male black rhinoceroses (Diceros bicornis), two male white rhinoceroses (Ceratotherium simum), two male one-horned Asian rhinoceroses (Rhinoceros unicornis), seven female black rhinoceroses, and six female white rhinoceroses from multiple institutions were examined to characterize their anatomy and histology. Some observations and measurements were obtained from in situ tracts of intact animals before or during necropsy. Formalin-fixed tissues were dissected and examined histologically. Retrospective reproductive data from each rhinoceros was obtained from the institutions of origin. Reproductive histology of these species was similar to that of other mammals. Male accessory gland structure varied among species, and the Asian rhinoceros epididymis was more loosely attached and had larger duct diameters than did the epididymides of the African species. Although histology was typically mammalian, rhinoceros reproductive morphology combined characteristics of several different mammals. Defining this unique morphology of rhinoceroses may help in understanding their reproductive physiology and will effect the development of appropriate reproductive techniques.

Animals↗
PubMed2000

Influence of diet on the hematology and serum biochemistry of zinc-intoxicated mallards.

Changes in hematological and serum biochemistry parameters in female zinc (Zn)-dosed farm-raised mallards (Anas platyrhynchos) fed four different diets were examined. Sixty ducks received an average dose of 0.97 g of Zn in the form of eight, 3.30-mm diameter shot pellets containing 98% Zn and 2% tin, and another 60 ducks were sham-dosed as controls. Fifteen ducks from each of the two dosing groups were assigned to one of four dietary treatments: corn only, corn with soil, commercial duck ration only, or commercial duck ration with soil. Shot-pellet dissolution rates ranged from 7 mg/Zn/day to 27 mg/Zn/day. Regardless of diet, the Zn dose resulted in mortality; incoordination; paralysis and anorexia; decreased body, liver, pancreas, gonad, and gizzard weight; increased kidney weight; and macroscopic lesions. Zn-dosed ducks had a lower mean erythrocyte packed cell volume (PCV), higher mean reticulocyte count, and a greater number of individuals with immature and/or abnormal erythrocytes, than did control mallards. Mean total leucocyte counts were higher in Zn-dosed ducks than in controls. Zn-dosed ducks that had soil available had higher leucocyte counts than those without soil. Zn-dosed ducks were characterized by a marked heterophilia and relative lymphopenia. In Zn-dosed ducks, the mean lymphocyte count was highest in those provided a commercial duck ration, and lowest in those fed corn. In control ducks, the mean lymphocyte count was highest in ducks fed corn, and lowest in those provided soil along with a commercial duck ration. Zn-dosed mallards had higher serum aspartate aminotransferase and amylase levels, and lower alkaline phosphatase activities than control ducks. Serum phosphorus and uric acid concentrations were higher, and calcium, glucose, and total protein levels lower, in Zn-dosed ducks than in control ducks. Diet did affect serum calcium, phosphorus, total protein, and uric acid concentrations. Differences in erythrocyte and leucocyte parameters, serum enzyme activities, and metabolite concentrations were associated with dose and diet effects. Diets high in protein and other organic matter and calcium and phosphorus did not prevent or substantially alleviate Zn toxicosis in farm-raised mallard ducks.

Animal Feed↗
PubMed1999

Changes in thyroid gland morphology after acute acrylamide exposure.

High exposure to the acrylamide monomer has been associated with neuropathy and neurotoxic effects. Chronic lower exposure causes endocrine disruption associated with thyroid, testicular, and mammary tumors. To investigate mechanisms of endocrine disruption, short-term, low-level oral dosing studies were conducted. Weanling female Fischer 344 rats were acclimatized for two weeks before dosing. Controls were given distilled water by gavage and rats in other groups were given acrylamide at doses of 2 mg/kg/day and 15 mg/kg/day for 2 or 7 days by gavage. Twenty-four h after the last dose, the rats were killed by decapitation. Trunk blood was collected for hormone analyses and tissues for histopathological examination. There were no toxicity-related deaths, no clinical signs of toxicity, and no significant difference in the mean body weight of animal groups. Histopathological examination of select tissues showed no lesions of pathologic significance. Plasma thyroxine (T4), thyroid stimulating hormone (TSH), prolactin (PRL), and pituitary TSH and PRL analyses did not reveal significant changes between control vs. treated rats. In the 7-day study, however, there was a slight dose-dependent increase in plasma T4 and a slight dose-dependent decrease in plasma TSH. Thyroid gland morphometry showed a significant (p < 0.05) decrease in the colloid area and a significant increase (p < 0.05) in the follicular cell height of treated rats as compared to controls. The follicular area shrinkage was similar in both studies. These results show a very early endocrine response to very low levels of toxic insult and opens other venues to further investigate the mechanisms of endocrine disruption by acrylamide.

Acrylamide↗
PubMed1998

Role of TGF-beta in RA-induced cleft palate in CD-1 mice.

Retinoic acid (RA) plays an important role in embryogenesis, by regulating morphogenesis, cell proliferation, differentiation, and extracellular matrix production. RA exposure on gestational day (GD) 12 in CD-1 mice results in delayed palatal shelf elevation and subsequent clefts in the secondary palate. Given the dynamic and complex nature of palate development, it is not surprising that this system is susceptible to changes in retinoid levels. There is evidence that experimental manipulation of retinoid status during development alters normal transforming growth factor-beta (TGF-beta) status. To study the role of perturbation in TGF-beta levels in RA-induced cleft palate, gravid CD-1 mice were treated with 70 mg/kg RA on GD 12. We examined changes in TGF-beta proteins and the steady-state level of TGF-beta mRNA within the first 24 hr after exposure. The interactions between RA and TGF-beta s were very complex. RA differentially regulated the mRNA and protein levels of TGF-beta 1. Changes in mRNA steady-state levels were rapid and transient in nature, indicating a direct mediation by RA. Differential regulation was evident, because RA treatment resulted in an increase in TGF-beta 1 mRNA steady levels followed by a decrease in the intracellular and extracellular forms of TGF-beta 1 protein. Moreover, the patterns of localization and levels of TGF-beta 2 and TGF-beta 3 proteins were not dramatically affected, although there was an increase in TGF-beta 3 mRNA steady-state levels. The increases in mRNA steady-state levels for TGF-beta 2 and TGF-beta 3, as for TGF-beta 1, were rapid and transient in nature, again arguing for direct mediation by RA. These data provide evidence for interactions between RA and TGF-beta s, and indicate that RA is capable of differentially regulating TGF-beta isoforms through processes involving different stages of TGF-beta synthesis and secretion. Further, changes in TGF-beta isoforms were observed prior to changes in mesenchyme morphology and must be considered as mediators of RA's effects on mesenchyme development.

Animals↗
PubMed1998

Forms and prevalence of intersexuality and effects of environmental contaminants on sexuality in cricket frogs (Acris crepitans).

Cricket frogs (Acris crepitans) from several different sites in Illinois were collected to assess the effects of environmental contamination on the prevalence of intersex gonads. Of 341 frogs collected in 1993, 1994, and 1995, 2.7% were intersex individuals. There was no statistically significant relationship between the chemical compounds detected and cricket frog intersexuality. However, there was an association approaching significance (p = 0.07) between the detection of atrazine and intersex individuals. A comparison of reference sites with sites that had point polychlorinated biphenyl (PCB) and polychlorinated dibenzofuran (PCDF) contamination revealed a significant relationship between sex-ratio reversal and contamination with PCBs and PCDFs. The sex ratio of juvenile frogs studied from three sites with PCB and PCDF point contamination favored males over females, which was the opposite of the sex ratio in control ponds (p = 0.0007). The statistically significant correlation between organochlorine contamination and sex-ratio reversal suggests PCBs and PCDFs can influence cricket frog sexual differentiation. The current study suggests that in cricket frogs, sex ratios and the prevalence of intersex gonads are altered by environmental contamination.

Aging↗
PubMed1998

Effects of lead, iron, and bismuth alloy shot embedded in the breast muscles of game-farm mallards.

Effects of five lead (Pb), iron (Fe), or bismuth (Bi)/tin (Sn) alloy shot embedded in the breast muscles of game-farm mallards (Anas platyrhynchos) were studied from 28 March 1994 through 27 March 1995. We detected no differences in the mean survival times, mean hematocrits, or mean body weights among the three shot types. Connective tissue encapsulated Pb and Bi/Sn shot but only slight changes occurred in tissues surrounding the shot. Recovered Pb and Bi/Sn shot were essentially unchanged in appearance and weight. A thin zone of "oxide" surrounded Fe shot with a slight inflammatory response and a small amount of scarring adjacent to the embedded shot. Fe shot decreased slightly in weight while embedded. Bacterial infections were absent in all dosed ducks. Mean weights of kidneys, livers, and gonads did not vary by type of shot. Kidneys and livers of Bi-dosed ducks had higher concentrations of Bi than in Pb- and Fe-dosed ducks. Muscle and blood showed no differences in Bi concentrations among doses. We found no histological dose-related effects in kidneys, liver, and gonads from the embedded shot.

Alloys↗
PubMed1997

Necrotic oophoritis in gilts associated with experimental inoculation of a viral gene-deletion mutant pseudorabies vaccine.

Previous work on the reproductive effects of various herpesviruses has demonstrated adverse effects on reproductive function in several host species. Although herpesviral vaccines are used in several species to ameliorate the clinical effects of infection, pathogenicity for reproductive tissue, associated with diminished reproductive efficiency, has been reported to be retained in a live-attenuated vaccine strain of the herpesvirus, bovine herpesvirus-1. The objective of this study was to determine if a gene-deletion mutant, thymidine kinase negative, pseudorabies virus retained acute pathogenicity for the reproductive tract of swine following intravenous inoculation during estrus. Estrous cycles of nulliparous gilts were synchronized by administration of a gonadotropin and daily exposure to a boar. During estrus, six gilts were inoculated intravenously with twice the recommended intramuscular dose of a commercially available viral gene-deletion mutant pseudorabies vaccine. Six control gilts in estrus were sham inoculated intravenously with vaccine diluent during estrus. All animals were euthanatized 10 days postinoculation, and the ovaries and uterus were collected for histopathology following gross examination. All reproductive tracts were grossly normal. Histologically, four of six treated gilts had a mild to moderate, multifocal, necrotizing oophoritis, with the lesions limited to corpora lutea and the adjacent stroma. Ovaries of control gilts exhibited to necrotizing lesions. Both control and pseudorabies vaccine-inoculated gilts had occasional minimal focal mononuclear infiltrates in the ovaries. These data show that live attenuated viral gene-deletion mutant pseudorabies vaccine administered to swine during estrus can result in acute pathogenicity in ovarian corpora lutea. No endocrinologic data is available in these pigs, so the impact on pregnancy maintenance is unknown.

Animals↗
PubMed1996

Pathology of the corpus luteum of cows.

The corpus luteum (CL) is a transient endocrine organ which can manifest a number of pathologic conditions such as cysts, inflammation, adhesions, dysfunction and neoplasia. Luteal and follicular cysts are the most commonly encountered abnormalities and need to be distinguished from cysts within a normal CL. Inflammatory lesions are also frequently encountered and can be caused by viral, bacterial, or iatrogenic causes. If inflammation is severe, adhesions and subfertility/infertility can result. Luteal dysfunction is a broad classification of another pathologic condition encountered in the cow. Generally this results in abnormal production of progesterone or abnormal luteal lifespan resulting in infertility. Neoplasms are relatively rare in the CL but include both primary and metastatic tumors. Understanding the pathologic conditions that occur within the CL will allow a more accurate clinical assessment of these very dynamic endocrine structures.

Journal Article↗
PubMed1996

Effects of 3-iodo-L-tyrosine, a tyrosine hydroxylase inhibitor, on eye pigmentation and biogenic amines in the planarian, Dugesia dorotocephala.

Planarians (Dugesia dorotocephala) were evaluated as bioassay organisms to detect inhibition of tyrosine hydroxylase, the rate-limiting enzyme in the synthesis of catecholamines. Thirty planaria per dose were exposed to 0 (control), 0.001, 0.01, 0.1, or 1 mM 3-iodo-L-tyrosine (monoiodotyrosine or MIT) in standard test media beginning 24 hr before decapitation and continuing for 13 days. Complete regeneration of normal heads occurred over the first 6 days in all dose groups, a response reported to be partially dependent on catecholamines. Beginning on Day 7, the black eye pigments began fading in the 0.1 and 1 mM dose groups and were completely absent macroscopically and histologically by Day 11. The 0, 0.001, and 0.01 mM dose groups did not lose visible eye pigments. On Day 13, 3 planaria/dose were harvested for histopathology; 15 planaria/dose were decapitated a second time and remained in MIT solutions; and 12 planaria/dose were left intact, placed in fresh control media, and evaluated for eye repigmentation. Normal head regeneration (including eyes) was detected grossly in all groups, even in those animals devoid of eye pigments at the time of decapitation. As before, eye pigments began fading 7 days after decapitation (Day 20 of experiment) and were completely absent in 73 and 33% of the animals in the 0.1 and 1 mM groups, respectively, on Day 25. All animals moved to control media reformed eye pigments, beginning within 48 hr. Analysis of the decapitated heads by HPLC-ECD on Day 13 revealed a significant decrease in dopamine and 5-hydroxytryptamine (serotonin) concentrations in MIT-exposed animals. Tyrosine hydroxylase activity (and possibly tyrosinase activity) was shown to be inhibited by the highest two concentrations for whole planaria homogenates in vitro.

Animals↗
PubMed1995

Rabies-induced spongiform change and encephalitis in a heifer.

A 1-year-old mixed breed heifer was presented to the Veterinary Medical Teaching Hospital at the University of Illinois with a 3-day history of abnormal mentation and aggressive behavior. Based on the history and clinical examination, euthanasia and necropsy were recommended. The differential diagnosis included rabies, pseudorabies, and a brain abscess. The brain was removed within 60 minutes of death, and the section submitted for fluorescent antibody testing was positive for rabies virus antigen. Residual brain tissue was immersion fixed in 10% neutral buffered formalin. Histologic examination revealed a marked perivascular and meningeal lymphocytic meningoencephalitis and locally extensive spongiform change of the gray matter affecting the neuropil and neuron cell bodies. The most severely affected regions with spongiform change were the thalamus and cerebral cortex. No Negri bodies were found in any sections. Since the outbreak of bovine spongiform encephalopathy (BSE) in the United Kingdom, there has been an increased surveillance of bovine neurologic cases in an effort to assess if BSE has occurred in the USA. In areas where rabies virus is endemic, rabies should be included as a possible differential diagnosis in cases of spongiform changes of the central nervous system.

Animals↗
PubMed1995

Fixation and staining of planaria for histological study.

Fixation and staining of planaria can affect the interpretation of histopathological changes following their exposure to various agents. We assessed several fixation protocols with various stains in planaria to determine an optimal combination. Planaria were fixed in each of the following: 10% neutral buffered formalin, 2.5%, glutaraldehyde, Bouin's, Zenker's, 70% ethanol, and relaxant. In addition, planaria were fixed in relaxant and postfixed in each of the fixatives above. Paraffin embedded sections from each fixation protocol were stained with hematoxylin and eosin (H & E), toluidine blue, periodic acid-Schiff (PAS), or phosphotungstic acid-hematoxylin (PTAH). Relaxant fixed planaria were also stained with Steiner's, Holmes, trichrome, Giemsa, Grocott's methenamine silver (GMS) and antibodies for intermediate filaments (cytokeratin, vimentin and desmin). Relaxant and Zenker's gave the best fixation with minimal artifacts. Formalin, glutaraldehyde, and ethanol were unacceptable because they caused contortions of the body, crenation, and a darkly pigmented epidermis. Gastroderm could be differentiated from stroma best when stained with H & E, toluidine blue and PTAH. Other organ systems differentially stained included the epidermis, marginal adhesion gland, nervous tissue, and muscle. PAS, Steiner's, Holmes, trichrome and the intermediate filament stains were not useful for planaria staining. The most morphological information was obtained with relaxant fixative and a combination of sections stained with H & E and PTAH.

Animals↗
PubMed1995

Evaluation of marking materials for cutaneous surgical margins.

Microscopic evaluation of the margins of excised cutaneous neoplasms is of paramount importance for determining that neoplastic tissue does not extend to the excision borders. Dyes or pigments that indelibly mark the tissue should be more reliable than sectioning techniques or suture markers for identifying the surgical margins before and after tissue processing. We evaluated 5 pigments to select a material that could be rapidly applied by surgeons, and readily identified on histologic section by the pathologists. Twenty normal canine skin specimens were assigned to each of 5 groups. Each group was treated with artists' pigments in acetone, India ink in acetone, alcian blue, typists' correction fluid, or a commercially available marking kit. Ten specimens within each group were marked before formalin fixation, and 10 were marked after fixation. Application properties, fixation and processing properties, and microscopic characteristics were evaluated for each material. Application properties were acceptable for all marking materials on unfixed specimens, and for alcian blue, India ink in acetone, and correction fluid on fixed specimens. Fixation and processing properties were acceptable for all materials except correction fluid. All marking materials survived fixation and processing, and colors were readily visualized under the microscope. Microscopic characteristics were acceptable for alcian blue, India ink in acetone, and the commercial kit. Overall, alcian blue was the best marking material, with India ink in acetone and the commercial kit also acceptable. Correction fluid and artist' pigments in acetone were not acceptable because pigment fragmentation and incomplete tissue coverage hindered microscopic evaluation of resection margins.

Alcian Blue↗
PubMed1994

Growth and ovarian function of weanling and yearling beef heifers grazing endophyte-infected tall fescue pastures.

Growth and ovarian function of crossbred beef heifers grazing low and high endophyte-infected tall fescue pastures were studied for 2 successive years. In April of each year, 20 weanling and 20 yearling heifers were included in the study. All heifers were weighed at 28-d intervals for 112 d. Blood samples were collected from each heifer on Day 0 and +7 of each of five 28-d periods and analyzed for progesterone concentration. Heifers with progesterone concentrations >/= 1.5 ng/ml on either or both Day 0 and +7 were classified as having normal cyclic ovaries. High endophyte-infected fescue pastures adversely altered the ovarian activity (P < 0.05) of weanling heifers in both years. In each trial, average weight gains were lower (P < 0.05) in yearling and weanling heifers grazing the high endophyte-infected pastures than in heifers grazing low endophyte-infected pastures. In 1992, heifers were synchronized with PGF(2alpha) administered on Days 101 and 112. Blood samples were collected on 0, 4, 8 and 12 d after the second PGF(2alpha) injection for progesterone analysis. Heifers grazing high and low endophyte-infected pastures were pastured separately with 4 bulls each and were given heatmount detectors. At 96 h, less estrus activity was observed (P < 0.10; power=0.63) in weanling heifers grazing the high vs. low endophyte pastures although pregnancy rates were similar for all groups. Progesterone concentrations suggested that weanling heifers on the high endophyte pastures had a higher incidence of luteal dysfunction after PGF(2alpha) synchronization. In summary, high endophyte-infected pastures decreased growth in both weanling and yearling heifers, ovarian activity and luteal function were adversely altered in weanling heifers with subsequent decreased estrus response to estrus synchronization.

Journal Article↗
PubMed1994

Retrospective studies on the measurements, karyotyping and pathology of reproductive organs of bovine freemartins.

A retrospective study of 217 cases of bovine freemartinism was made. Of these, 14 cases were diagnosed clinically, 141 were karyotyped and 62 were subjected to macroscopical examination of the reproductive tract. Of the 62 cases, 43 were assessed by measuring the reproductive organs (size and/or weight) and 41 were examined microscopically. Complete information on gross, histopathological and karyotyping analysis was available for only 10 animals. Freemartins showed reduced measurements of all reproductive organs. The mean lengths of vulva and vagina were 6.4 cm and 8.1 cm, respectively. Vesicular glands were observed in 30 freemartins. Histologically, these glands had more fibrous and less glandular tissue than the normal male vesicular glands. Uterine changes were variable, ranging from aplasia (two animals) to normal. Likewise, endometrial glands ranged from hypoplastic (decreased number and size) to normal. Glandular and myometrial cells showed prominent nuclei and less than normal cytoplasm, indicating a non-functional status. Gonadal size was reduced and an epididymis was present in seven animals. Rete ovarii were prominent and frequently occupied two-thirds of the gonad. Undifferentiated sex cords and abundant interstitial cells were salient features of the freemartin gonad. Oocytes were not observed. Ovarian follicles were seen in six cases. Karyotypic analyses demonstrated XY chimaerism in all freemartins.

Animals↗
PubMed1994

Bacterial endotoxemia and reproductive effects in ruminants.

Gram-negative bacterial infections are fairly common in domestic ruminants. They can cause an endotoxemia with a variety of systemic signs, including fever, leukopenia, and ruminal stasis. Reproductive effects of endotoxemia include alterations in the estrous cycle and inability to maintain pregnancy. Diagnosis of endotoxemia is based largely on clinical evaluation. Confirming the diagnosis of endotoxin-induced reproductive alterations also is complicated by the lag period between clinical signs and abortion or infertility.

Abortion, Veterinary↗
PubMed1994

Effect of Salmonella endotoxin administered to the pregnant sheep at 133-142 days gestation on fetal oxygenation, maternal and fetal adrenocorticotropic hormone and cortisol, and maternal plasma tumor necrosis factor alpha concentrations.

We studied the effects of maternal exposure to endotoxin on pregnancy outcome, stimulation of the hypothalamo-hypophyseal-adrenal axes (HHAA) of ewes and their fetuses, and maternal production of tumor necrosis factor alpha (TNF alpha), a central mediator in the pathogenesis of bacterial endotoxemia. Either endotoxin (lipopolysaccharide, LPS) from Salmonella typhimurium or saline was administered to pregnant sheep (n = 10) at 137.6 +/- 3.5 days gestational age by slow i.v. infusion at 1 microgram.kg-1 total dose over a 3-h period. Fetuses of ewes treated with LPS became hypoxemic by 2.5 h after initiation of LPS infusion. Maternal ACTH increased and peaked during LPS administration to levels approximately 10-fold greater in treated than in control ewes. In contrast, fetal ACTH levels were maximum at 6-12 h. Maternal and fetal cortisol levels were significantly different from control levels by 1 and 12 h, respectively. Maternal plasma TNF alpha peaked (6-7-fold over baseline) at 1-2 h after initiation of LPS administration and steadily declined over the following 48 h. Four of 5 treated ewes either delivered or their fetuses died within 28 h. In summary, infusion of LPS caused fetal hypoxemia and stimulated both fetal and maternal HHAA followed by preterm labor by 28 h after infusion in 4 of 5 ewes. Three of the fetuses died in utero. Maternal plasma TNF alpha rose rapidly, but the specific role it may play in initiation of preterm labor remains to be elucidated.

Adrenocorticotropic Hormone↗