Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Mol Biol Rep ; 48(2): 1935-1942, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33566223

RESUMO

The zoos manage small populations of endangered big cat species like tiger, lion, and leopard for display, research, and conservation breeding. Genetic management of these populations is essential to ensure long term survival and conservation utility. Here we propose a simple and cost effective microsatellite based protocol for the genetic management of captive big cats. We sampled 36 big cat individuals from Seoul Grand Park Zoo (Republic of Korea) and amplified 33 published microsatellite loci. Overall, allelic richness and gene diversity was found highest for leopards, followed by lions and tigers. Twelve of the thirty-three markers showed a high degree of polymorphism across all target species. These microsatellites provide a high degree of discrimination for tiger (1.45 × 10-8), lion (1.54 × 10-10), and leopard (1.88 × 10-12) and thus can be adopted for the genetic characterization of big cats in accredited zoos globally. During captive breeding, zoo authorities rely on pedigree records maintained in studbooks to ensure mating of genetically fit unrelated individuals. Several studies have reported errors in studbook records of big cat species. Microsatellites are simple and cost effective tool for DNA fingerprinting, estimation of genetic diversity, and paternity assessment. Our unified microsatellite panel (12-plex) for big cats is efficient and can easily be adopted by zoo authorities for regular population management.


Assuntos
Animais de Zoológico/genética , Leões/genética , Repetições de Microssatélites , Panthera/genética , Tigres/genética , Alelos , Animais , Animais de Zoológico/sangue , Primers do DNA , Variação Genética , Genótipo , Leões/sangue , Leões/metabolismo , Panthera/sangue , Linhagem , Polimorfismo Genético , República da Coreia , Seleção Artificial/genética , Seul , Tigres/sangue , Tigres/metabolismo
2.
J Zoo Wildl Med ; 48(2): 298-311, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28749296

RESUMO

The International Species Information System has set forth an extensive database of reference intervals for zoologic species, allowing veterinarians and game park officials to distinguish normal health parameters from underlying disease processes in captive wildlife. However, several recent studies comparing reference values from captive and free-ranging animals have found significant variation between populations, necessitating the development of separate reference intervals in free-ranging wildlife to aid in the interpretation of health data. Thus, this study characterizes reference intervals for six biochemical analytes, eleven hematologic or immune parameters, and three hormones using samples from 219 free-ranging African lions ( Panthera leo ) captured in Kruger National Park, South Africa. Using the original sample population, exclusion criteria based on physical examination were applied to yield a final reference population of 52 clinically normal lions. Reference intervals were then generated via 90% confidence intervals on log-transformed data using parametric bootstrapping techniques. In addition to the generation of reference intervals, linear mixed-effect models and generalized linear mixed-effect models were used to model associations of each focal parameter with the following independent variables: age, sex, and body condition score. Age and sex were statistically significant drivers for changes in hepatic enzymes, renal values, hematologic parameters, and leptin, a hormone related to body fat stores. Body condition was positively correlated with changes in monocyte counts. Given the large variation in reference values taken from captive versus free-ranging lions, it is our hope that this study will serve as a baseline for future clinical evaluations and biomedical research targeting free-ranging African lions.


Assuntos
Animais Selvagens , Animais de Zoológico , Leões/sangue , Alanina Transaminase/sangue , Fosfatase Alcalina/sangue , Animais , Glicemia , Sedimentação Sanguínea , Nitrogênio da Ureia Sanguínea , Creatinina/sangue , Feminino , Grelina/sangue , Leptina/sangue , Contagem de Leucócitos/veterinária , Leucócitos/fisiologia , Masculino , Neutrófilos , Valores de Referência , África do Sul , Testosterona/sangue
3.
J Zoo Wildl Med ; 45(2): 328-34, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25000694

RESUMO

A prospective study to assess changes in selected plasma biochemistry and electrolyte values, plasma insulin and aldosterone concentrations, and electrocardiography (ECG) was performed on eight female captive tigers (Panthera tigris) and three lions (Panthera leo) undergoing general anesthesia for elective laparoscopic ovariectomy. Each animal was sedated with medetomidine (18-25 microg/kg) and midazolam (0.06-0.1 mg/kg) intramuscularly, and anesthesia was induced with ketamine (1.9-3.5 mg/kg) intramuscularly and maintained with isoflurane. Venous blood samples were collected and analyzed for plasma biochemistry parameters and insulin and aldosterone concentrations. An ECG was recorded at the time of each blood sample collection. Mean plasma potassium, glucose, phosphorus, and aldosterone concentrations increased during anesthesia (P < or = 0.05). One tiger developed hyperkalemia (6.5 mmol/L) 2.5 hr after anesthetic induction. Plasma insulin concentrations were initially below the low end of the domestic cat reference interval (72-583 pmol/L), but mean insulin concentration increased (P < or = 0.05) over time compared with the baseline values. Three tigers and two lions had ECG changes that were representative of myocardial hypoxemia. Based on these results, continuous monitoring of clinical and biochemical alterations during general anesthesia in large nondomestic felids is warranted, and consideration should be given to reversal of medetomidine in these animals should significant changes in electrolytes or ECG occur.


Assuntos
Anestesia Geral/veterinária , Eletrólitos/sangue , Leões/sangue , Tigres/sangue , Animais , Feminino , Valores de Referência
4.
Sci Rep ; 10(1): 20323, 2020 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-33230252

RESUMO

Experimental studies suggest involvement of trimethylamine N-oxide (TMAO) in the aetiology of cardiometabolic diseases and chronic kidney disease (CKD), in part via metabolism of ingested food. Using a comparative biomimetic approach, we have investigated circulating levels of the gut metabolites betaine, choline, and TMAO in human CKD, across animal species as well as during hibernation in two animal species. Betaine, choline, and TMAO levels were associated with renal function in humans and differed significantly across animal species. Free-ranging brown bears showed a distinct regulation pattern with an increase in betaine (422%) and choline (18%) levels during hibernation, but exhibited undetectable levels of TMAO. Free-ranging brown bears had higher betaine, lower choline, and undetectable TMAO levels compared to captive brown bears. Endogenously produced betaine may protect bears and garden dormice during the vulnerable hibernating period. Carnivorous eating habits are linked to TMAO levels in the animal kingdom. Captivity may alter the microbiota and cause a subsequent increase of TMAO production. Since free-ranging bears seems to turn on a metabolic switch that shunts choline to generate betaine instead of TMAO, characterisation and understanding of such an adaptive switch could hold clues for novel treatment options in burden of lifestyle diseases, such as CKD.


Assuntos
Biomimética/métodos , Hibernação/fisiologia , Metilaminas/sangue , Insuficiência Renal Crônica/sangue , Ursidae/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Betaína/sangue , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/mortalidade , Colina/sangue , Feminino , Microbioma Gastrointestinal , Humanos , Leões/sangue , Masculino , Pessoa de Meia-Idade , Myoxidae/sangue , Estudos Prospectivos , Insuficiência Renal Crônica/complicações , Sus scrofa/sangue , Tigres/sangue
5.
Onderstepoort J Vet Res ; 76(3): 317-21, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21105599

RESUMO

Due to logistical problems in obtaining sufficient blood samples from apparently healthy animals in the wild in order to establish normal haematological reference values, only limited information regarding the blood platelet count and morphology of free-living lions (Panthera leo) is available. This study provides information on platelet counts and describes their morphology with particular reference to size in two normal, healthy and free-ranging lion populations. Blood samples were collected from a total of 16 lions. Platelet counts, determined manually, ranged between 218 and 358 x 10(9)/l. Light microscopy showed mostly activated platelets of various sizes with prominent granules. At the ultrastructural level the platelets revealed typical mammalian platelet morphology. However, morphometric analysis revealed a significant difference (P < 0.001) in platelet size between the two groups of animals. Basic haematological information obtained in this study may be helpful in future comparative studies between animals of the same species as well as in other felids.


Assuntos
Leões/anatomia & histologia , Leões/sangue , Contagem de Plaquetas/veterinária , Animais , Plaquetas/ultraestrutura , Feminino , Masculino , Valores de Referência , Especificidade da Espécie
6.
J Zoo Wildl Med ; 38(4): 591-3, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18229868

RESUMO

Lions (Panthera leo) are an endangered species threatened by illegal hunting, habitat loss, and infectious diseases. Little is known about the tick-borne pathogens that infect lions and could contribute to population declines. The objective of this study was to characterize Rickettsia spp., Anaplasma phagocytophilum, and Coxiella burnetii infections in 10 lions from the Fasano Safari Park in Italy by serology, polymerase chain reaction, and sequence analysis. Although animals did not show clinical signs of tick-borne diseases, evidence of infection with C. burnetii, spotted fever group Rickettsia sp., and A. phagocytophilum were found in 50%, 20%, and 10% of the lions, respectively. One of the lions tested positive for all three pathogens. This study is the first report of molecular evidence of infection with C. burnetii, Rickettsia sp., and A. phagocytophilum in lions and provides evidence that these felids become infected and serve as hosts for tick-transmitted bacteria.


Assuntos
Anticorpos Antibacterianos/sangue , Leões , Doenças Transmitidas por Carrapatos/veterinária , Anaplasma/imunologia , Anaplasma/isolamento & purificação , Animais , Vetores Aracnídeos/microbiologia , Coxiella/imunologia , Coxiella/isolamento & purificação , Feminino , Itália/epidemiologia , Leões/sangue , Reação em Cadeia da Polimerase/veterinária , Rickettsia/imunologia , Rickettsia/isolamento & purificação , Estudos Soroepidemiológicos , Testes Sorológicos/veterinária , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/epidemiologia , Carrapatos/microbiologia
7.
Arterioscler Thromb Vasc Biol ; 24(3): 564-70, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14726411

RESUMO

OBJECTIVE: The aim of this study was to investigate the molecular mechanism for changes in proteoglycan binding and LDL receptor affinity on two compositional changes in LDL that have been associated with atherosclerosis: cholesterol enrichment of the core and modification by secretory group IIA phospholipase A2 (sPLA2) of the surface. METHODS AND RESULTS: Transgenic mice expressing recombinant apolipoprotein (apo) B and sPLA2 were generated. Recombinant LDL were isolated and tested for their proteoglycan and LDL receptor-binding activity. The results show site A (residues 3148-3158) in apoB100 becomes functional in sPLA2-modified LDL and that site A acts cooperatively with site B (residues 3359-3369), the primary proteoglycan-binding site in native LDL, in the binding of sPLA2-modified LDL to proteoglycans. Our results also show that cholesterol enrichment of LDL is associated with increased affinity for proteoglycans and for the LDL receptor. This mechanism is likely mediated by a conformational change of site B and is independent of site A in apoB100. CONCLUSIONS: Site A in apoB100 becomes functional in sPLA2-modified LDL and acts cooperatively with site B resulting in increased proteoglycan-binding activity. The increased binding for proteoglycans of cholesterol-enriched LDL is solely dependent on site B.


Assuntos
Apolipoproteínas B/química , Lipoproteínas LDL/metabolismo , Proteoglicanas/metabolismo , Substituição de Aminoácidos , Animais , Apolipoproteína B-100 , Apolipoproteínas B/genética , Apolipoproteínas B/metabolismo , Arteriosclerose/metabolismo , Biglicano , LDL-Colesterol/metabolismo , Decorina , Proteínas da Matriz Extracelular , Fosfolipases A2 do Grupo II , Humanos , Leões/sangue , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosfolipases A/metabolismo , Fosfolipases A2 , Ligação Proteica , Conformação Proteica , Mapeamento de Interação de Proteínas , Estrutura Terciária de Proteína , Receptores de LDL/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes/metabolismo , Deleção de Sequência , Especificidade da Espécie
8.
J Zoo Wildl Med ; 36(3): 417-21, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17312758

RESUMO

Heparinized whole-blood samples from 22 adult African lions (Panthera leo) fed diets considered nutritionally adequate in 10 American Zoo and Aquarium Association member zoos in North America were provided for this study. Blood thiamine values were estimated using a standard microbiological assay method. The mean +/- standard deviation for blood thiamine values was 249.3 +/- 43.5 nmol/L with a range in values from 160 to 350 nmol/L after exclusion of one outlier. There were no differences (P > 0.05) in the mean blood thiamine values of male and female lions, or of lions that were over and under 10 yr of age. This range (160 to 350 nmol/L) is proposed as a reasonable estimate of the expected range in blood thiamine values for captive adult African lions as currently fed in North American zoos.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Leões/sangue , Tiamina/sangue , Complexo Vitamínico B/sangue , Fatores Etários , Animais , Animais de Zoológico/sangue , Feminino , Masculino , Estado Nutricional , Valores de Referência , Fatores Sexuais
9.
Res Vet Sci ; 41(2): 268-9, 1986 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3775118

RESUMO

Normal haematological values and fibrinogen levels were obtained from a number of healthy adult Felidae in the collection of the Zoological Society of London. The group comprised 29 pumas (Felis concolor), 32 lions (Panthera leo), 27 tigers (P tigris), 19 leopards (P pardus), 18 jaguars (P onca) and 22 cheetahs (Acinonyx jubatus). The values provided a basis for identifying abnormalities in the blood of sick individuals of these species and for undertaking interspecies comparisons.


Assuntos
Acinonyx/sangue , Carnívoros/sangue , Leões/sangue , Animais , Fibrinogênio/análise , Valores de Referência
10.
J Wildl Dis ; 14(1): 102-9, 1978 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-633506

RESUMO

Fifty-eight immobilizations were conducted using 21 lions (Panthera leo) and 4 drug combinations. The combinations used were ketamine-phencyclidine-promazine, xylazine-phencyclidine-promazine, xylazine-ketamine-phencyclidine-promazine, and tiletamine-zolazepam.


Assuntos
Equilíbrio Ácido-Base , Animais de Zoológico/sangue , Carnívoros/sangue , Imobilização , Leões/sangue , Animais , Dióxido de Carbono/sangue , Ketamina , Oxigênio/sangue , Fenciclidina , Promazina , Tiletamina , Xilazina
11.
J S Afr Vet Assoc ; 84(1): E1-7, 2013 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-23718570

RESUMO

Certain carnivore research projects and approaches depend on successful capture of individuals of interest. The number of people present at a capture site may determine success of a capture. In this study 36 lion capture cases in the Kruger National Park were used to evaluate whether the number of people present at a capture site influenced lion response rates and whether the number of people at a sampling site influenced the time it took to process the collected samples. The analyses suggest that when nine or fewer people were present, lions appeared faster at a call-up locality compared with when there were more than nine people. The number of people, however, did not influence the time it took to process the lions. It is proposed that efficient lion capturing should spatially separate capture and processing sites and minimise the number of people at a capture site.


Assuntos
Criação de Animais Domésticos/métodos , Leões/sangue , Restrição Física , Animais , Humanos , Leões/fisiologia , Veículos Automotores , Fatores de Tempo
12.
Res Vet Sci ; 95(1): 266-8, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23415881

RESUMO

Hematologic and serum chemistry values are used by veterinarians and wildlife researchers to assess health status and to identify abnormally high or low levels of a particular blood parameter in a target species. For free-ranging lions (Panthera leo) information about these values is scarce. In this study 7 hematologic and 11 serum biochemistry values were evaluated from 485 lions from the Kruger National Park, South Africa. Significant differences between sexes and sub-adult (≤ 36 months) and adult (>36 months) lions were found for most of the blood parameters and separate reference intervals were made for those values. The obtained reference intervals include the means of the various blood parameter values measured in captive lions, except for alkaline phosphatase in the subadult group. These reference intervals can be utilized for free-ranging lions, and may likely also be used as reference intervals for captive lions.


Assuntos
Leões/sangue , Fatores Etários , Fosfatase Alcalina/sangue , Animais , Nitrogênio da Ureia Sanguínea , Colesterol/sangue , Contagem de Eritrócitos/veterinária , Índices de Eritrócitos , Feminino , Globulinas/metabolismo , Hematócrito/veterinária , Hemoglobinas/metabolismo , Contagem de Leucócitos/veterinária , Modelos Lineares , Masculino , Valores de Referência , Albumina Sérica/metabolismo , Fatores Sexuais , África do Sul
13.
Vet Microbiol ; 162(2-4): 972-976, 2013 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-23123173

RESUMO

Infections with feline hemotropic mycoplasmas (hemoplasmas) have been documented in domestic cats and free-ranging feline species with high prevalences in Iberian lynxes (Lynx pardinus), Eurasian lynxes (Lynx lynx), European wildcats (Felis silvestris silvestris), African lions (Panthera leo) in Tanzania and domestic cats in South Africa. The prevalence of hemoplasmas has not yet been investigated in free-ranging felids in southern Africa. In this study we screened 73 blood samples from 61 cheetahs in central Namibia for the presence of hemoplasmas using quantitative real-time PCR. One of the cheetahs tested PCR-positive. Phylogenetic analysis based on partial sequencing of the 16S rRNA and RNAse P genes revealed that the isolate belongs to the Mycoplasma haemofelis/haemocanis group. This is the first molecular evidence of a hemoplasma infection in a free-ranging cheetah.


Assuntos
Acinonyx/microbiologia , Infecções por Mycoplasma/veterinária , Mycoplasma/isolamento & purificação , Acinonyx/sangue , Animais , Gatos , Feminino , Leões/sangue , Leões/microbiologia , Masculino , Mycoplasma/classificação , Mycoplasma/genética , Infecções por Mycoplasma/epidemiologia , Infecções por Mycoplasma/microbiologia , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Reação em Cadeia da Polimerase em Tempo Real , África do Sul/epidemiologia , Tanzânia/epidemiologia
14.
Vet Immunol Immunopathol ; 149(3-4): 292-7, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22921684

RESUMO

The ongoing spread of bovine tuberculosis (BTB) in African free-ranging lion populations, for example in the Kruger National Park, raises the need for diagnostic assays for BTB in lions. These, in addition, would be highly relevant for zoological gardens worldwide that want to determine the BTB status of their lions, e.g. for translocations. The present study concerns the development of a lion-specific IFN-γ assay, following the production and characterization of monoclonal antibodies specific for lion interferon-gamma (IFN-γ). Recombinant lion IFN-γ (rLIFN-γ) was produced in mammalian cells and used to immunize mice to establish hybridoma cell lines producing monoclonal antibodies. These were used to develop a sensitive, lion IFN-γ-specific capture ELISA, able to detect rLIFN-γ to the level of 160 pg/ml. Recognition of native lion IFN-γ was shown in an initial assessment of supernatants of mitogen stimulated whole blood cultures of 11 known BTB-negative lions. In conclusion, the capture ELISA shows potential as a diagnostic assay for bovine tuberculosis in lions. Preliminary results also indicate the possible use of the test for other (feline) species.


Assuntos
Ensaio de Imunoadsorção Enzimática/veterinária , Interferon gama/análise , Interferon gama/imunologia , Leões/imunologia , Mycobacterium bovis/imunologia , Tuberculose/veterinária , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Bovinos , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Interferon gama/sangue , Interferon gama/genética , Leões/sangue , Leões/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium bovis/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Sensibilidade e Especificidade , Tuberculose/sangue , Tuberculose/imunologia , Tuberculose/microbiologia
15.
Vet Radiol Ultrasound ; 51(1): 34-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20166390

RESUMO

Osseous malformations in the skull and cervical vertebrae of lions in captivity are believed to be caused by hypovitaminosis A. These often lead to severe neurologic abnormalities and may result in death. We describe the characterization of these abnormalities based on computed tomography (CT). CT images of two affected and three healthy lions were compared with define the normal anatomy of the skull and cervical vertebrae and provide information regarding the aforementioned osseous malformations. Because bone structure is influenced by various factors other than the aforementioned disease, all values were divided by the skull width that was not affected. The calculated ratios were compared and the most pronounced abnormalities in the affected lions were, narrowing of the foramen magnum, thickening of the tentorium osseus cerebelli and thickening of the dorsal arch of the atlas. CT is useful for detection of the calvarial abnormalities in lions and may be useful in further defining this syndrome.


Assuntos
Vértebras Cervicais/diagnóstico por imagem , Hiperostose/veterinária , Leões/anatomia & histologia , Crânio/diagnóstico por imagem , Tomografia Computadorizada por Raios X/veterinária , Animais , Animais de Zoológico , Feminino , Hiperostose/diagnóstico por imagem , Hiperostose/etiologia , Leões/sangue , Masculino , Deficiência de Vitamina A/sangue , Deficiência de Vitamina A/complicações , Deficiência de Vitamina A/veterinária
16.
Ann N Y Acad Sci ; 1160: 179-85, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19416182

RESUMO

The human population explosion has pushed many mammalian wildlife species to the brink of extinction. Conservationists are increasingly turning to captive breeding as a means of preserving the gene pool. We previously reported that serum immunoactive relaxin provided a reliable means of distinguishing between true and pseudopregnancy in domestic dogs, and this method has since been found to be a reliable indicator of true pregnancy in endangered Asian and African elephants and Sumatran rhinoceroses. Our canine relaxin radioimmunoassay (RIA) has now been adapted and validated to measure relaxin in the serum and urine of felids, including domestic and wild species. Moreover, a commercially available canine serum relaxin kit (Witness) Relaxin Kit; Synbiotics, San Diego, CA), has been adapted for reliable detection of relaxin in urine of some felid species. Our porcine relaxin RIA has also been utilized to investigate the role of relaxin in reproductive processes of the spotted hyena, a species in which the female fetuses are severely masculinized in utero. Indeed, this species might well now be extinct were it not for the timely secretion of relaxin to enable copulation and birth of young through the clitoris. Additional studies have suggested relaxin may be a useful marker of pregnancy in the northern fur seal and the maned wolf (the former species has been designated as "depleted" and the latter as "near threatened"). Given appropriate immunoassay reagents, relaxin determination in body fluids thus provides a powerful tool for conservationists and biologists investigating reproduction in a wide variety of endangered and exotic species.


Assuntos
Relaxina/sangue , Relaxina/urina , Acinonyx/sangue , Acinonyx/urina , Animais , Gatos , Cães , Felidae/sangue , Felidae/urina , Feminino , Imunoensaio , Leões/sangue , Leões/urina , Gravidez , Relaxina/análise
17.
PLoS Negl Trop Dis ; 2(12): e347, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19065258

RESUMO

Trypanosomes cause disease in humans and livestock throughout sub-Saharan Africa. Although various species show evidence of clinical tolerance to trypanosomes, until now there has been no evidence of acquired immunity to natural infections. We discovered a distinct peak and decrease in age prevalence of T. brucei s.l. infection in wild African lions that is consistent with being driven by an exposure-dependent increase in cross-immunity following infections with the more genetically diverse species, T. congolense sensu latu. The causative agent of human sleeping sickness, T. brucei rhodesiense, disappears by 6 years of age apparently in response to cross-immunity from other trypanosomes, including the non-pathogenic subspecies, T. brucei brucei. These findings may suggest novel pathways for vaccinations against trypanosomiasis despite the notoriously complex antigenic surface proteins in these parasites.


Assuntos
Leões/imunologia , Trypanosoma brucei brucei/imunologia , Tripanossomíase Africana/imunologia , Imunidade Adaptativa , África Subsaariana , Envelhecimento , Animais , Animais Selvagens/imunologia , Suscetibilidade a Doenças/imunologia , Ecossistema , Humanos , Leões/sangue , Modelos Teóricos , Modelos de Riscos Proporcionais , Estudos Soroepidemiológicos , Taxa de Sobrevida , Sobreviventes , Árvores/parasitologia , Tripanossomíase Africana/epidemiologia , Tripanossomíase Africana/mortalidade , Tripanossomíase Africana/veterinária , Moscas Tsé-Tsé/parasitologia
18.
J Reprod Fertil ; 57(2): 267-72, 1979 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-513015

RESUMO

During a 6-month study period weekly serum samples demonstrated 9 oestradiol surges above 14 pg/ml (range 19-108 pg/ml) among 3 lionesses isolated from male lions. Intervals between peaks ranged from 3 to 8 weeks. Progesterone surges of more than 17 ng/ml (range 17-282 ng/ml) and lasting for 2-6 weeks were recorded after 7 of the oestradiol peaks. Sexual behaviour correlated well with the oestradiol peaks. Except for cornification following oestradiol peaks, there was no obvious vaginal cytology pattern at other times of the cycle. Pregnancy occurred after a 12-h contact with a male during behavioural oestrus. During gestation (108 days) oestradiol values remained low, while progesterone was elevated to 49 ng/ml within 12 h after mating, reaching a peak of 143 ng/ml at the 4th week, and remaining elevated during the next 2 months.


Assuntos
Carnívoros/sangue , Estradiol/sangue , Estro , Leões/sangue , Prenhez , Progesterona/sangue , Animais , Feminino , Leões/fisiologia , Gravidez , Comportamento Sexual Animal/fisiologia , Vagina/citologia
19.
J Reprod Fertil ; 97(1): 107-14, 1993 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8385220

RESUMO

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)


Assuntos
Animais Selvagens/sangue , Hormônios/sangue , Leões/sangue , Glândulas Suprarrenais/efeitos dos fármacos , Hormônio Adrenocorticotrópico/farmacologia , Animais , Feminino , Hormônio Foliculoestimulante/sangue , Variação Genética , Hormônio Liberador de Gonadotropina/farmacologia , Hidrocortisona/sangue , Leões/genética , Hormônio Luteinizante/sangue , Hipófise/efeitos dos fármacos , Hipófise/metabolismo , Progesterona/sangue
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA