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At least 19 recordsLinked to original sources
PubMed2006

Trichinella zimbabwensis in wild reptiles of Zimbabwe and Mozambique and farmed reptiles of Ethiopia.

In 1995, a new species of Trichinella (Trichinella zimbabwensis) was discovered in farmed Nile crocodiles (Crocodylus niloticus) in Zimbabwe, where the mode of transmission was the consumption of the meat of slaughtered crocodiles, used as feed. To determine whether T. zimbabwensis affects poikilotherm vertebrates in the wild, monitor lizards (Varanus niloticus) and Nile crocodiles were collected in Zimbabwe and Mozambique. In 5 (17.6%) of the 28 monitor lizards from Zimbabwe, T. zimbabwensis larvae were identified. For the wild Nile crocodiles from Mozambique, species-level identification was not possible, yet immunohistochemical analysis revealed that 8 (20%) of the 40 animals harboured non-encapsulated Trichinella sp. larvae, which probably belonged to T. zimbabwensis. This is the first report of T. zimbabwensis in wild reptiles, and the findings are consistent with reports that vertebrates with scavenger and cannibalistic behaviour are the most important hosts of Trichinella spp. The wide distribution of monitor lizards and crocodiles in Africa and the development of national crocodile breeding programs in many African countries should be taken into consideration when evaluating the risk of transmission of this parasite to mammals, including humans.

Alligators and Crocodiles↗
PubMed1980

The brain of the mammal-like reptile Probainognathus jenseni (Therapsida, Cynodontia). A correlative paleo-neoneurological approach to the neocortex at the reptile-mammal transition.

A natural endocranial cast of the South American cynodont Probainognathus jenseni is studied, and an evaluation of the probable nature of the neocortex at the level of certain cynodonts of the Middle Triassic is made, based in the available paleo-neoneurological information. The endocast of Probainognathus shows well developed olfactory bulbs, long cerebral hemispheres, small anterior colliculi and well represented cerebellum and flooculi. The pineal gland may have been located between the caudal hemispheric poles. No parietal foramen exists. The dorsal surface of the cerebral hemispheres shows a slope at the level of the anterior edge of the caudal fourth part, which is interpreted as the posterior limit of the neocortical plate. At the level of the olfactory peduncles, it is visible a stem vessel; one of its branches distributes on the anterior part of the lateral border of the hemisphere. It is advanced the interpretation that this latter vessel could indicate the paleo-neocortical boundary. The analysis of the neoneurological information led the author to suppose that the neocortex of Probainognathus, and surely of other cynodonts of the Middle Triassic, has shown supplementary somatic sensory and motor, visual and auditory representations, and perhaps incipient primary somati sensory and motor ones, advancing a "polymodal cortex", as it is supposed had stem mammals. Moreover, the histostructure of the neocortex at this state of the evolution may have been in a proisocortical-isocortical stage, that is, in the beginnings of the true neocortex. The confrontation of the paleoneurologic with the neoneurologic information led the author to suppose that Triconodon and Ptilodus have had a neocortex, surely more developed than Probainognathus, but that it is not seen in the endocasts at present studied. The quantitative analysis of Probainognathus' endocast, as well as those of other cynodonts, suggest that certain cynodonts of the Middle Triassic were in an advanced state toward endothermy.

Animals↗
PubMed1984

Oxygen storage capacity and tolerance of submergence of a non-aquatic reptile and an aquatic reptile.

The oxygen storage capacities and the tolerance to submergence of an aquatic snake, Natrix sipedon, and a non-aquatic snake, Crotalus viridis, were determined and compared. C. viridis was found to have a larger oxygen storage capacity, hemoglobin content and blood volume than N. Sipedon. The submergence time for C. viridis was 30.13 min which was less than the estimated time for submergence based on the oxygen storage capacity. N. sipedon exceeded its estimated dive time of 24.00 min and remained submerged for 65.57 min without signs of stress. During submergence, the heart rate of N. sipedon fell to 9% (5 beats/min) of the resting rate, while the heart rate of C. viridis fell to only 75% (27 beats/min) of the resting rate during this activity. These data indicate that N. sipedon responds to submergence via a typical diving reflex and extends its oxygen stores beyond that expected of a non-diver such as C. viridis.

Animals↗
PubMed2006

Future directions in reptile medical education.

Reptile medicine has emerged as a specialty area within the broader field of zoological medicine. It encompasses the medical needs of approximately 7,500 vertebrate species. This vertebrate class is highly diversified, having biological and medical peculiarities that differ both between and within major groups. Historically, veterinarians who have become recognized specialists with reptiles have had limited formal training in their medical management. The pet reptile trade is a multi-million-dollar business, and the popularity of reptiles as pets has resulted in a need for more veterinarians with training in their medical management. While few private practices have high volumes of reptile cases, many small-animal practices will have the opportunity to see a significant number of reptiles on an annual basis. Most practitioners with reptile medical expertise have merged their experiences as reptile pet owners with the principles of veterinary medicine taught in veterinary college. Several North American veterinary colleges have reptile medicine courses, and most have didactic and clinical courses in exotic and zoo animal medicine that include lectures and practical experience. Most accredited zoological medicine residency training programs include training in reptile medicine. The case load and interest in reptile medicine will probably never be sufficient to lead the average veterinary college to develop much more than what is currently offered. Consequently, those few colleges having more extensive course offerings, both didactic and clinical, will serve as educational centers for this discipline. Future Web-based teaching programs in reptile medicine will allow students nationally and internationally to have access to instructional material that can be continually updated.

Animals↗
PubMedDate not supplied

Further characterization of the major forms of reptile beta-endorphin.

Biosynthetically labeled reptile intermediate pituitary beta-endorphin-sized material was fractionated by SP-Sephadex ion exchange chromatography into two major opiate-active forms which eluted at 0.28 M NaCl and 0.32 M NaCl, respectively; the 0.32 M form of reptile beta-endorphin (mw = 3500), serves as the precursor for the 0.28 M form of reptile beta-endorphin (mw = 3200), (Dores and Surprenant, 1983). Analysis of tryptic digests of these reptile beta-endorphins by paper electrophoresis at pH 3.5 and gel filtration on a Sephadex G-15 column indicated that there are two tyrosine residues, two arginine residues and one methionine residue in reptile beta-endorphin. Furthermore, the NH2-terminal tryptic peptide of both reptile beta-endorphins is approximately nine amino acids in size and contains tyrosine, methionine and arginine. Analyses of chymotryptic/protease digests of the [3H]tyrosine-labeled NH2-terminal tryptic peptide analyzed by descending paper chromatography revealed that the NH2-terminal tyrosine of reptile beta-endorphin is not alpha-N-acetylated. A second tyrosine-containing tryptic peptide was detected in the COOH-terminal region of reptile beta-endorphin; however this tryptic peptide differs in the two forms of reptile beta-endorphin in terms of size and net charge at pH 3.5. These differences account for the apparent molecular weight differences and distinct ion exchange properties of the 0.28 M and 0.32 M forms of reptile beta-endorphin. Thus in the reptile intermediate pituitary the principal post-translational mechanism for modifying beta-endorphin is COOH-terminal proteolytic cleavage.

Animals↗
PubMed2005

Immunohistochemical study on gastrointestinal endocrine cells of four reptiles.

AIM: To clarify the types, regional distributions and distribution densities as well as morphological features of gastrointestinal (GI) endocrine cells in various parts of the gastrointestinal track (GIT) of four reptiles, Gekko japonicus, Eumeces chinensis, Sphenomorphus indicus and Eumeces elegans. METHODS: Paraffin-embedded sections (5 mum) of seven parts (cardia, fundus, pylorus, duodenum, jejunum, ileum, rectum) of GIT dissected from the four reptiles were prepared. GI endocrine cells were revealed by using immunohistochemical techniques of streptavidin-peroxidase (S-P) method. Seven types of antisera against 5-hydroxy-tryptamine (5-HT), somatostatin (SS), gastrin (GAS), glucagon (GLU), substance P (SP), insulin and pancreatic polypeptide were identified and then GI endocrine cells were photomicrographed and counted. RESULTS: The GI endocrine system of four reptiles was a complex structure containing many endocrine cell types similar in morphology to those found in higher vertebrates. Five types of GI endocrine cells, namely 5-HT, SS, GAS, SP and GLU immunoreactive (IR) cells were identified in the GIT of G. japonicus, E. chinensis and S. indicus; while in the GIT of E. elegans only the former three types of endocrine cells were observed. No PP- and INS- IR cells were found in all four reptiles. 5-HT-IR cells, which were most commonly found in the pylorus or duodenum, distributed throughout the whole GIT of four reptiles. However, their distribution patterns varied from each other. SS-IR cells, which were mainly found in the stomach especially in the pylorus and/or fundus, were demonstrated in the whole GIT of E. chinensis, only showed restricted distribution in the other three species. GAS-IR cells, with a much restricted distribution, were mainly demonstrated in the pylorus and/or the proximal small intestine of four reptiles. GLU-IR cells exhibited a limited and species-dependent variant distribution in the GIT of four reptiles. SP-IR cells were found throughout the GIT except for jejunum in E. elegans and showed a restricted distribution in the GIT of G. japonicus and S. indicus. In the GIT of four reptiles the region with the highest degree of cell type heterogeneity was pylorus and most types of GI endocrine cells along the GIT showed the peak density in pylorus as well. CONCLUSION: Some common and unique features of the distribution and morphology of different types of GI endocrine cells are found in four reptiles. This common trait may reflect the similarity in digestive physiology of various vertebrates.

Animals↗
PubMed2002

Salmonella enterica in reptiles of German and Austrian origin.

Captive reptiles are routinely identified as reservoirs of Salmonella spp. and the number of reports about reptile-associated salmonellosis is increasing. In the present study, Salmonella were detected in 86 of 159 (54.1%) faecal reptile samples cultured. The percentage of Salmonella positive samples was significantly lower in turtles as compared with lizards and snakes, as Salmonella were only detected in one sample from a single turtle out of 38 turtles investigated. In all, 42 different Salmonella serovars were found. All isolated Salmonella belonged to the species enterica, predominantly to the subspecies I (n=46) and IIIb (n=30), but also to subspecies II (n=3), IIIa (n=6) and IV (n=2). All isolates were sensitive to the antimicrobials examined. A comparison between the reptile owners indicated that either no Salmonella were found, or that Salmonella could be isolated from all or nearly all animals of the respective owners. A significantly higher percentage of Salmonella positive reptiles was detected in the group of owners who purchase reptiles in comparison with pure breeders. A total of 88.9% of Salmonella isolates were found in samples of reptiles bought in pet shops and 58.8% in samples from wild-caught animals. The high percentage of Salmonella in reptiles in our study confirms the risk for the transmission of the infection to humans.

Animals↗
PubMed2006

Respiratory cooling and thermoregulatory coupling in reptiles.

Comparative physiological research on reptiles has focused primarily on the understanding of mechanisms of the control of breathing as they relate to respiratory gases or temperature itself. Comparatively less research has been done on the possible link between breathing and thermoregulation. Reptiles possess remarkable thermoregulatory capabilities, making use of behavioural and physiological mechanisms to regulate body temperature. The presence of thermal panting and gaping in numerous reptiles, coupled with the existence of head-body temperature differences, suggests that head temperature may be the primary regulated variable rather than body temperature. This review examines the preponderance of head and body temperature differences in reptiles, the occurrence of breathing patterns that possess putative thermoregulatory roles, and the propensity for head and brain temperature to be controlled by reptiles, particularly at higher temperatures. The available evidence suggests that these thermoregulatory breathing patterns are indeed present, though primarily in arid-dwelling reptiles. More importantly, however, it appears that the respiratory mechanisms that have the capacity to cool evolved initially in reptiles, perhaps as regulatory mechanisms for preventing overheating of the brain. Examining the control of these breathing patterns and their efficacy at regulating head or brain temperature may shed light on the evolution of thermoregulatory mechanisms in other vertebrates, namely the endothermic mammals and birds.

Adaptation, Physiological↗
PubMed1998

Reptiles as models of contaminant-induced endocrine disruption.

Historically, reptiles have been used as bioindicators of environmental contaminants and, currently, reptiles have the potential to elucidate the mechanisms of a newly described group of environmental contaminants--endocrine disrupters. Reptiles are particularly good models for studying endocrine altering compounds due to the fact that different species of reptiles have varying modes of gender determination (genotypic sex determination or temperature-dependent sex determination) and parity modes (oviparity or viviparity). This review focuses both on laboratory and field studies of contaminant-induced endocrine alterations in reptiles. Laboratory studies of oviparous reptiles with temperature-dependent sex determination reveal that embryonic exposure to natural hormones and many man-made chemicals (including the ubiquitous PCBs and common herbicides) can permanently alter the functioning of the reproductive system. It is hypothesized that similar permanent, organizational changes occur in wild reptiles exposed to endocrine-disrupting contaminants.

Animals↗
PubMed1995

Reptile-associated salmonellosis in New York State.

To determine the association between reptile ownership and salmonellosis caused by certain rare serotypes of Salmonella, we reviewed 1993 New York State Salmonella case reports and conducted a matched case-control study. Cases were persons identified from 1993 New York State laboratory records who had salmonellosis caused by Salmonella serotypes commonly isolated from reptiles. Controls were selected from 1993 New York State shigellosis cases and matched for age and date of diagnosis. Of 674 Salmonella case reports 27 (4%) noted reptile exposure before onset of illness. For the case-control study we identified 42 persons with selected Salmonella serotypes, of whom we contacted 24 (57%). Twelve of 24 case patients and 2 of 28 controls owned reptiles (matched odds ratio, 6.6; 95% confidence interval, 1.4 to 31.0). Ten case-patients but no controls owned iguanas (MOR = undefined; 95% confidence interval, 2.24-infinity). Ten of 12 case patients who owned reptiles were < or = 6 months of age. Salmonellosis caused by certain serotypes is associated with reptile exposure. Reptiles may be unfit pets for homes with infants.

Adolescent↗
PubMed2001

In vitro inhibition of Salmonella organisms isolated from reptiles by an inactivated culture of microcin-producing Escherichia coli.

OBJECTIVE: To determine whether an inactivated culture of a microcin-producing avian Escherichia coli was capable of killing Salmonella isolates from reptiles in an in vitro test system. SAMPLE POPULATION: 57 Salmonella isolate from reptiles. PROCEDURE: A wild-type avian E. coli electrotransformed with a plasmid coding for the production of microcin 24 was tested in an in vitro microassay system for its ability to kill 57 Salmonella spp isolated from reptiles. The reptile population included snakes, iguana, frilled lizards, turtles, other lizards, and unspecified reptiles. RESULTS: 44 of the Salmonella isolates were inhibited strongly, compared with the in vitro assay controls; 12 had weak inhibition, and 1 was not inhibited by the microcin-producing E. coli. Thirteen of the 57 isolates had resistance to at least 1 antibiotic, primarily streptomycin. There were 9 O serogroups identified in the 57 isolates, with serogroup H being the most prevalent (18 to 57). CONCLUSION AND CLINICAL RELEVANCE: Antibiotics are not recommended to eliminate Salmonella organisms from reptiles because of the development of antibiotic resistance. Further studies are necessary to determine whether the use of microcin-producing bacteria will be effective in controlling Salmonella infections in companion reptiles.

Animals↗
PubMed1977

Body temperature and tumor virus infection. I. Tumorogenicity of Rous sarcoma virus for reptiles.

Rous sarcoma virus (RSV) was oncogenic for the following nine species of reptiles representing 6 families from Chelonia and Squamata orders: family of Testudinidae: 1. Testudo horsfieldi, family Agamidae: 2. Agama sanguinolenta; 3. Agama erythrogastra, family Lacertidae: 4. Eremias persica; 5. Eremias velox; 6. Eremias grammica, family Scincidae: 7. Eumeces taeniolatus, family Boidea: 8. Erix tataricus, 9. Ancistrodom blomhoffi. RSV did not induce tumors in 13 studied species of reptiles. Histologically 26 reptile tumors studied were polymorphous sarcomas with spindle-shaped (fibroblast-like), round and polygonal macrophage-like cells and sometimes peculiar giant polynuclear cells. Chromosomal analysis showed that reptile tumors arose out of reptile cells. RSV was pathogenic for adult reptiles. Reptile tumors did not contain a mature infectious virus. The tumors of 2 snakes were virogenic. The effect of increased temperature at the body level on the transformation of a symptomless viral infection into a viral disease is discussed in the evolutionary aspect.

Animals↗
PubMed1980

Basal ganglionic pathways to the tectum: studies in reptiles.

Relations between the basal ganglia and the tectum were investigated in two different orders of reptiles: turtles (Chrysemys scripta) and crocodilians (Caiman crocodilus). In both species, efferents from the paleostriatal complex, a telencephalic region considered comparable to the mammalian basal ganglia on the basis of topographic, histochemical, and hodological criteria, were found to project to a prominent pretectal cell group called the dorsal nucleus of the posterior commissure (nDCP). Cells within nDCP, in turn, were found to project extensively upon the optic tectum. This paleostriatal-pretectal-tectal pathway is comparable to a previously described paleostriatal-pretectal-tectal channel in birds that involves a relay in the pretectal nucleus, spiriformis lateralis (SpL). Neither the presently described paleostriatal-pretectal-tectal channel of reptiles nor that previously described in birds, however, appears comparable to the superficially similar basal ganglionic-nigral-superior collicular pathway of mammals. Rather, data from the present experiments indicate the existence of a second paleostriatal channel to the tectum, one which does appear comparable to the basal ganglionic-nigral-superior collicular pathway of mammals. This second paleostriatal channel to the tectum, relayed via a tegmental cell group termed the substantia nigra in turtles and the tegmentipedunculopontine complex in caiman, is of much lesser prominence in reptiles than the paleostriatal-pretectal-tectal channel. The present results indicate the existence of at least two separate systems by which the basal ganglia in reptiles can influence the midbrain roof. These two channels, particularly the prominent paleostriatal-pretectal-tectal pathway, may represent major routes by which the basal ganglia influence motor functions in reptiles. Further, although previous research had only indicated the existence of a paleostriatal-pretectal-tectal pathway in birds and a basal ganglionic-nigral-collicular channel in mammals, existing data are consistent with the hypothesis that both presently described pathways in reptiles exist in birds and mammals, though only one of the two may be prominent in mammals.

Alligators and Crocodiles↗
PubMed2004

Reptile-associated salmonellosis in preschool-aged children in Michigan, January 2001-June 2003.

OBJECTIVES: Determine the incidence of reptile-associated salmonellosis in preschool-aged children in Michigan. METHODS: Cases of reptile-associated salmonellosis in children < or =5 years of age occurring in Michigan January 2001-June 2003 were identified through review of individual patient case-history forms provided by local health departments to the Michigan Department of Community Health and by identification of Michigan Department of Community Health laboratory-confirmed cultures of reptile-associated serotypes, determined by evaluation of the Public Health Laboratory Information System's Clinical Nonhuman Salmonella data for 1990-2001. RESULTS: The incidence of reptile-associated salmonellosis was 11.8% of all Salmonella cases reported in Michigan children aged < or =5 years for the period January 2001 through June 2003. CONCLUSIONS: Despite the recommendations of the Centers for Disease Control and Prevention to avoid the exposure of children <5 years old to reptiles, reptile-associated salmonellosis in preschool-aged children continues to be a public health problem in Michigan.

Animals↗