Search results for "Dog"
showing 10 items of 1087 documents
DNA repair protein O6-methylguanine-DNA methyltransferase in testis and testicular tumors as determined by a novel nonradioactive assay
2003
The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT, alkyltransferase) is an important suicide enzyme involved in defense against O6-alkylating endogenous metabolites and environmental carcinogens. It also plays a pivotal role in primary and acquired resistance of tumors to alkylating anticancer drugs targeting the O6-position of guanine (i.e., methylating and chloroethylating agents). MGMT can thus be considered a crucial biomarker for individual susceptibility to alkylating carcinogens and tumor drug resistance. This implies a need for a fast and convenient method for determination of MGMT. Routinely, MGMT is being quantified by radioactive assays which are relatively labo…
ITS-2 rDNA sequencing of Gnathostoma species (Nematoda) and elucidation of the species causing human gnathostomiasis in the Americas.
2000
From several gnathostome species the complete internal transcribed spacer ITS-2 ribosomal DNA (rDNA) repeat sequence and a fragment of the 5.8S rDNA were obtained by direct polymerase chain reaction cycle-sequencing and silver-staining methods. The size of the complete ITS-1 sequence in agarose gel electrophoresis was also obtained. The ITS-2 enabled the differentiation of Gnathostoma spinigerum from Thailand and Gnathostoma binucleatum from Mexico and Ecuador and confirmed the validity of the latter. Gnathostoma turgidum, Gnathostoma sp. I (=Gnathostoma procyonis sensu Almeyda-Artigas et al., 1994), and Gnathostoma sp. II (=G. turgidum sensu Foster, 1939 pro parte), all from Mexico, proved…
GHB differentially affects morphine actions on motor activity and social behaviours in male mice
2003
There are several reports suggesting that gamma-hydroxybutyric acid (GHB) influences the endogenous opioid system. The present study aimed to investigate the effects of GHB on motor and social activities and to examine its influence on morphine's actions on these behaviours. In a first experiment, several doses of GHB were studied but only the highest (200 and 400 mg/kg) produced a decrease in spontaneous motor activity measured in an actimeter cage. When hyperactivity induced by injecting 50 mg/kg of morphine was evaluated, all the GHB doses efficiently counteracted this morphine action. Using the paradigm of isolation-induced aggression, administration of 200 mg/kg of GHB significantly de…
Isolation decreases physical and motivational aspects of morphine withdrawal
2005
Environmental manipulations such as social housing conditions of animals may play a role in the expression of individual differences in response to drugs. This study aimed to evaluate whether isolated and grouped mice develop different degrees of morphine dependence. Isolated and grouped mice were rendered morphine dependent employing two different methods of induction: a fast or slow protocol, both reaching the same maximum daily dose (100 mg/kg). Naloxone-induced morphine withdrawal was assessed using a modified Gellert-Holtzman scale and a conditioned place aversion (CPA) procedure. Isolated animals manifested fewer signs of physical dependence than grouped mice and only those receiving …
Influence of Ketamine anaesthesia on renal and cardiovascular functions in mongrel dogs
1979
Cardiac minute volume, renal blood flow, pulse volume, heart rate and urinary output were determined by means of experiments made on 10 mongrel dogs. Anaesthesia was maintained by nitrous oxide/oxygen mixture administered with Ketamine. Under the conditions described it was observed that -- contrary to what is found in human patients -- cardiac and renal minute volume as well as pulse volume are significantly decreased. No significant changes has been observed in the heart rate. Whilst urinary output was decreased, the excretion of individual electrolytes was found to be different.
Nicotinic and muscarinic modulation of 5-hydroxytryptamine (5-HT) release from porcine and canine small intestine
1992
Strips of porcine and canine small intestine were incubated in vitro and the release of 5-hydroxytryptamine (5-HT) was determined by HPLC with electrochemical detection. The spontaneous outflow of 5-HT from the porcine and canine small intestine largely reflects calcium-dependent 5-HT secretion from enterochromaffin cells which are under a spontaneous neuronal, excitatory input as indicated by the inhibitory effect (30-40%) of tetrodotoxin. In both species, nicotine enhanced the release of 5-HT in a concentration-dependent manner by a maximum of about 50% at 100 microM. This effect was blocked by the nicotine receptor antagonist hexamethonium, but not by the subtype-selective nicotine recep…
Morphometric analysis of cardiac conduction fibers in horses and dogs, a comparative histological and immunohistochemical study with findings in huma…
2021
Abstract The principal function of the ventricular conduction system is rapid electrical activation of the ventricles. The aim of this study is to conduct a morphometric study to pinpoint the morphological parameters that define cardiac conduction cells, allowing us to distinguish them from other cells. Five male horse hearts and five male dog hearts were used in the study. The hearts were fixed in a 5% formaldehyde solution. Histological sections of 5 μm thickness were acquired and stained with hematoxylin-eosin and Masson's trichrome and cardiac conduction cells and their junctions were identified by desmin, connexin 40 and a PAS method. We found statistically significant differences in c…
Cyclooxygenase-2 Expression Is Related With Localization, Proliferation, and Overall Survival in Canine Melanocytic Neoplasms
2011
A direct relationship has been firmly established between cyclooxygenase-2 (COX-2) expression and malignant behavior in human melanoma. This report examines the relationship between COX-2 expression and tumor location, mitotic and proliferative indices, degree of T CD3+ lymphocyte infiltration, overall survival, and frequency of recurrence and metastasis of 57 melanocytic tumors (25 oral and 32 cutaneous). COX-2 was highly or moderately expressed in 88% of oral neoplasms (22 of 25), whereas for their cutaneous counterparts, COX-2 expression was low or insignificant in 75% of cases (24 of 32). High and moderate COX-2 expression levels were observed in 73% of melanocytic tumors with a mitoti…
Periodontal impact of surgically induced dental lesions in mandibular osteodistraction: An animal study.
2009
SUMMARY. Aim: The objective of the study was to evaluatethe impact of dental lesions on the periodontium, in a canine model of mandibular osteodistraction. Material and methods: In six adult male Beagle dogs, an osteotomy was made between the right second lateral incisor and canine, and a distraction device placed. The roots adjacent to the osteotomy were deliberately damaged by the reciprocating saw and chisel, with preservation of the attached gingiva. The osteodistraction protocol used was: latency of 7 days, rate of distraction 1 mm per day, and rhythm once a day for 5 days. Vital staining was carried out with tetracycline, Xylenol Orange and Calcein Green. The dogs were sacrificed afte…
The effects of three absorption-modifying critical excipients on the in vivo intestinal absorption of six model compounds in rats and dogs.
2018
Pharmaceutical excipients that may affect gastrointestinal (GI) drug absorption are called critical pharmaceutical excipients, or absorption-modifying excipients (AMEs) if they act by altering the integrity of the intestinal epithelial cell membrane. Some of these excipients increase intestinal permeability, and subsequently the absorption and bioavailability of the drug. This could have implications for both the assessment of bioequivalence and the efficacy of the absorption-enhancing drug delivery system. The absorption-enhancing effects of AMEs with different mechanisms (chitosan, sodium caprate, sodium dodecyl sulfate (SDS)) have previously been evaluated in the rat single-pass intestin…