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PubMed1991

Comparison of the hemodynamic effects of halothane alone and halothane combined with epidurally administered morphine for anesthesia in ventilated dogs.

The hemodynamic effects of 1.5 minimal alveolar concentration of halothane alone (1.6% end-tidal) and 1.5 minimal alveolar concentration of halothane (1.1% end-tidal concentration) combined with epidurally administered morphine were compared during controlled ventilation in 10 dogs used on 2 occasions and randomly allocated to 2 groups. Arterial blood pressure, cardiac index, stroke volume, left ventricular work, and pulmonary arterial pressure were significantly (P less than 0.05) higher in dogs of the morphine-treated group before administration of morphine. After epidural administration of morphine (0.1 mg/kg of body weight diluted in 0.26 ml of saline solution/kg), hemodynamic changes were not observed, and the aforementioned variables remained significantly (P less than 0.05) higher than values in dogs of the halothane only group. Compared with halothane (1.6%) alone, the reduction in halothane end-tidal concentration (1.1%) associated with epidurally administered morphine is beneficial in maintaining hemodynamic function.

Anesthesia↗

PubMed1984

Inhibition of experimental colorectal cancer by razoxane (ICRF-159).

Large bowel cancer induced in rats by dimethylhydrazine (DMH) closely resembles human disease both histologically and clinically. In this study it has been used to assess the antimitotic drug razoxane (ICRF-159). Dimethylhydrazine induced benign colorectal tumours after 20 weeks and adenocarcinomas from 30 weeks. Razoxane was given from week 25 until the end of experiment (week 35) to see if this drug could inhibit the development of tumours. Animals were randomly allocated to four groups: DMH + razoxane (26), DMH + control (26), control + razoxane (25), control + control (25). There were fewer malignant colorectal tumours in rats receiving razoxane than in the controls (10 vs. 24; P = 0.04). Some animals developed malignant tumours of the small intestine as well as the large bowel and the number of malignant tumours for the whole intestinal tract was also reduced in animals receiving razoxane (15 vs. 32; P = 0.025). This study demonstrates inhibition of the development of malignant tumours in rats by razoxane. This finding may have relevance to colorectal cancer in man where razoxane has been used in disseminated disease and as an adjuvant to surgery.

1,2-Dimethylhydrazine↗

PubMed2003

Norepinephrine and vital organ blood flow during experimental hyperdynamic sepsis.

OBJECTIVE: To study the effect of norepinephrine (NE) infusion on cerebral, coronary, renal and mesenteric blood flow during sepsis. DESIGN AND SETTING: Randomised placebo-controlled animal trial in the animal laboratory of university physiology institute. ANIMALS: Seven merino cross-ewes. INTERVENTIONS: Chronic implantation of flow probes (aorta, renal, mesenteric and coronary artery and sagittal sinus). Induction of sepsis by intravenous bolus of E. coli (3 x 10(9)). After the onset of hyperdynamic sepsis sheep were randomly allocated to either NE (0.4 microg kg(-1) min(-1)) or placebo for 6 h. MEASUREMENTS AND RESULTS: E. coli induced hypotension, fever, oliguria, tachycardia and tachypnoea. It increased cardiac output and renal, mesenteric and coronary blood flows. Sagittal flow remained unchanged. Compared to placebo NE infusion restored mean arterial blood pressure and further increased cardiac output. The increases in renal, mesenteric and coronary blood flow were unaffected. Sagittal flow was also unaltered. Compared to placebo NE increased myocardial performance, mean urine output and creatinine clearance at 2 h. CONCLUSIONS: We conclude that hyperdynamic sepsis increases blood flow to heart, gut and kidney and that NE further increases cardiac output, blood pressure, myocardial performance, and urine output and creatinine clearance while maintaining regional blood flow.

Animals↗

PubMed2004

[Effects of genistein on bone mineral density and biomechanical properties and morphometric parameters in ovariectomized rats].

OBJECTIVE: To investigate the effects of genistein on bone mineral density and biomechanical properties and morphometric parameters in ovariectomized rats. METHODS: Forty-seven Wistar rats were randomly allocated into six groups: sham-operated (sham), ovarietomized (ovx), ovarietomized supplied with diethyl stilbestrol (E, 20 microg/kg BW) or genistetin (25, 50, 100 mg/kg BW). After the rats had been fed for three months, the bone mineral density and biomechanical properties and histomorphometric parameters of the rats was analysed. RESULTS: The trabecular bone volume and the mean trabecular plate density and bone density of ovariectomized rats were significantly decreased, while the mean trabecular plate space increased compared with sham animals. After three months supplementation to ovariectomized rats, trabecular bone volume and mean trabecular plate density increased. CONCLUSION: Genistein can reduced bone loss on ovariecromized rats.

Animals↗

PubMed2002

Study of crib-biting and gastric inflammation and ulceration in young horses.

Nineteen young horses that had recently started to perform the stereotypy of crib-biting were compared with 16 non-stereotypic horses for 14 weeks. After initial observations of their behaviour and an endoscopic examination of the condition of their stomachs, the horses were randomly allocated to a control or an antacid diet At the start of the trial, the stomachs of the crib-biting foals were significantly more ulcerated and inflamed than the stomachs of the normal foals. In addition, the faecal pH of the crib-biting foals (6.05) was significantly lower than that of the normal foals (6.58). The antacid diet resulted in a significant improvement in the condition of the horses' stomachs. The crib-biting behaviour declined in most of the foals, regardless of their diet, but tended to decline to a greater extent in the foals on the antacid diet.

Animal Husbandry↗

PubMed1987

The effect of intrauterine inoculation with Ureaplasma diversum on bovine fertility.

To determine the influence of Ureaplasma diversum on bovine fertility 11 uninfected virgin heifers with normal ovarian cyclic activity were randomly allocated to test or control groups. At a synchronized estrus, five test heifers were given an intrauterine broth inoculum containing 1.09 x 10(8) to 1.4 x 10(9) colony forming units of U. diversum and six control animals were infused with sterile ureaplasma broth medium. All animals were artificially inseminated within one hour of infusion. Pregnancy was diagnosed in one of five test heifers and all of six controls by serum progesterone concentrations measured to 25 days postinsemination. The difference in pregnancy rates between the two groups was statistically significant (p = 0.0152). It was concluded that under the conditions of this experiment U. diversum is capable of causing infertility in cattle.

Animals↗

PubMed2000

Safety of moxidectin in avermectin-sensitive collies.

OBJECTIVE: To evaluate the safety of moxidectin administration at doses of 30, 60, and 90 microg/kg of body weight (10, 20, and 30 times the manufacturer's recommended dose) in avermectin-sensitive Collies. ANIMALS: 24 Collies. PROCEDURE: Collies with mild to severe reactions to ivermectin challenge (120 mg/kg; 20 times the recommended dose for heartworm prevention) were used. Six replicates of 4 dogs each were formed on the basis of body weight and severity of reaction to ivermectin test dose. Within replicates, each dog was randomly allocated to treatment with oral administration of 30, 60, or 90 microg of moxidectin/kg or was given a comparable volume of placebo tablet formulation. Dogs were observed hourly for the first 8 hours and twice daily thereafter for 1 month for signs of toxicosis. RESULTS: Signs of toxicosis were not observed in any control group dog throughout the treatment observation period. Likewise, signs of toxicosis were not observed in any dog receiving moxidectin at 30, 60, or 90 microg/kg. CONCLUSIONS AND CLINICAL RELEVANCE: The moxidectin formulation used in the study reported here appears to have a wider margin of safety than ivermectin or milbemycin in avermectin-sensitive Collies.

Administration, Oral↗

PubMed2002

[Effects of dietary calcium-deficiency on bone development in growing rats and the mechanism involved].

The effects of calcium on bone development in growing rats were studied by bone histomorphometry and the hormone changes in a model of calcium-deficient rats. Thirty growing Wistar rats were randomly allocated into three groups fed with low calcium diet, calcium-sufficient diet at libitum or pair fed with low calcium diet for 8 weeks. The calcium-deficient rats showed low bone mass, significantly decreased bone density and mineral content. The disorder of bone molding and ultrastructure at the femoral distal diaphysis of the calcium deficient rats were showed by histomorphometric parameters. The concentration of serum parathyroid hormone was significantly higher, calcitonin was significantly lower, and the content of hydroxyproline in bone was significantly lower. The results indicated that dietary calcium-deficiency might stimulate the secretion of parathyroid hormone, decrease bone mineral content and inhibit the synthesis of bone matrix, which might induce a defect on bone mineralization.

Animals↗

PubMed2005

[Study of beta-defensin-2 gene expression in the pulmonary tissue of the older rat stimulated by pneumococcal vaccine polyvalent].

OBJECTIVE: To investigate the effect of pneumococcal vaccine polyvalent (pneumovax23) on defensin-2 gene expression in older rats. METHODS: Twenty older male Wistar rats (18-22 months) weighing (600 +/- 50) g were randomly allocated into two groups. The rats of experimental group were intraperitoneally injected with pneumovax23 0.2 ml/kg; the rats of control group were intraperitoneally injected with equivalent normal saline. Semiquantitive reverse transcription polymerase chain reaction (RT-PCR) was performed to detect beta-defensin-2 mRNA expression; beta-actin was used as the internal standard. RESULTS: The expression of beta-defensin-2 gene increased in the experimental group, as compared with that in the control group. CONCLUSION: Pneumovax23 can upregulate the expression of rBD-2 gene in the lung tissue and enhance the body local immunity. These experimental data indicate that Pneumovax23 can be used to enhance beta-defensin-2 and hence protect the old rats from pneumococci.

Aging↗

PubMed1984

Perivascular axillary block III: blockade following 40 ml of 0.5%, 1% or 1.5% mepivacaine with adrenaline.

Perivascular axillary blockade was performed on 90 patients with the aid of a catheter technique. All blockades were performed by the same anaesthetist, who practised perivascular axillary blockade three or four times a day. The patients were randomly allocated to three groups. The injected volume of local anaesthetic was constant in each group: 40 ml mepivacaine with adrenaline. The concentration and, consequently, the amount (mg) were variable factors: 1/2% (200 mg), 1% (400 mg) and 1 1/2% (600 mg). Sensory and motor blockade were tested 30 min after each injection. All three groups showed a high incidence of analgesia (70%-100%) in all cutaneous segments, and none of the blockades showed total failure of the sensory blockade. The lowest incidence of sensory blockade was found in the areas innervated by the axillary, the radial and the musculocutaneous nerves, but no difference was found between the groups. However, the motor blockade was found to improve with increasing concentration of local anaesthetic solution.

Adult↗

PubMed1993

Inhibition of hepatic microsomal drug metabolism by atracurium administration in the rat.

The muscle relaxant atracurium is known to undergo extrahepatic degradation via Hofmann elimination and ester hydrolysis. The purpose of the present study was to evaluate the effects of atracurium on hepatic P450-dependent enzyme activities. Thirty-two male Sprague-Dawley rats were anaesthetized, mechanically ventilated, and randomly allocated to one of four study groups: group 1 received saline, group 2 atracurium, group 3 vecuronium, and group 4 pancuronium intravenously for a period of 3 hr. Equipotent doses of the muscle relaxants were applied; the doses had been obtained in a pilot study using evoked electromyography. At the end of the study period, the livers were removed and analyzed. All three muscle relaxants may lead to inhibition of hepatic drug metabolism. Atracurium influences hepatic P450, although it is predominantly degraded in extrahepatic tissues. Further studies are needed to evaluate the contribution of the major metabolite laudanosine to this inhibitory action.

Aminopyrine N-Demethylase↗

PubMed1985

A comparison of the effects of cyclosporin A and standard agents on primary wound healing in the rat.

Eighty-six Sprague-Dawley rats were randomly allocated to three treatment groups given tap water (control group), cyclosporin A (CSA group) and azathioprine and prednisone (AP group). Two incisions, one skin and one musculofascial, were made in each rat with a standardized technique. The healed incisions were subjected to tensiometery at days eight and 15 after operation. Histologic examination was undertaken on some wounds. The results indicate that cyclosporin A in clinical doses does not inhibit skin or musculofascial healing in the rat. Azathioprine and prednisone immunosuppression significantly retarded skin healing on day eight postoperatively although this had returned to control levels on day 15. Azathioprine and prednisone did not affect musculofascial healing at the administered dose. In the sections available for study, there were no qualitative histologic differences between groups at both days eight and 15 postoperatively.

Animals↗

PubMed1995

Effect of exogenous oestrogen on blood flow and quantitative histology of the corpora lutea of pseudopregnant rabbits.

The effect of exogenous oestrogen on blood flow and quantitative histology of the corpus luteum were studied in pseudopregnant rabbits. Pseudopregnancy was induced with human chorionic gonadotrophin and an oestradiol capsule was implanted on day 0 of pseudopregnancy. Regression of the corpus luteum was initiated in the mid-luteal phase by removal of the capsule. Thirty-two New Zealand white rabbits were randomly allocated to four groups (eight rabbits per group) for studies of blood flow--control: oestradiol capsule not removed: -24 h: oestradiol capsule removed 24 h before blood flow measurements; -48 h: oestradiol capsule removed for 48 h; and -48 h/+48 h: oestradiol capsule removed for 48 h and then reimplanted for an additional 48 h. All blood flow studies were performed on day 11 of pseudopregnancy with radioactive microspheres. Quantitative histology was performed on a separate group of 16 rabbits allocated to the same groups as above (four rabbits per group). Blood flow to the corpus luteum was unchanged in the -24 h group, but declined by 44% in the -48 h group. Blood flow returned to control values in the -48 h/+48 h group. Quantitative histology revealed no changes in the -24 h group, but a significant decrease in volume of the corpus luteum and volume of the luteal cell cytoplasm in the -48 h group. Corpus luteum volume was fully restored and luteal cell cytoplasm volume was partially restored in the -48 h/+48 h group. In contrast, the number of luteal cells, vessel space volume and capillary surface area did not change with oestrogen withdrawal.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2005

Evaluation of remotely delivered leuprolide acetate as a contraceptive agent in female elk (Cervus elaphus nelsoni).

Practical application of fertility control technology in free-ranging wild ungulates often requires remote delivery of the contraceptive agent. The objective of this investigation was to evaluate the potential of remote delivery of leuprolide acetate for suppressing fertility in female elk (Cervus elaphus nelsoni). Fifteen captive adult female elk were randomly allocated to one of three experimental groups. Six elk were injected intramuscularly with a dart containing leuprolide, and the remaining nine elk received the same formulation without leuprolide. We determined pregnancy rates, suppression of luteinizing hormone (LH) and progesterone concentrations, and reversibility of treatments during 1 August 2002 to 3 September 2003. Leuprolide formulation caused a decrease in concentrations of LH and progesterone, temporary suppression of ovulation and steroidogenesis, and effective contraception (100%) for one breeding season. These results extend the practical application of this contraceptive agent to include dart delivery, where in the absence of such technology, wild elk must first be captured and restrained before treatment.

Animals↗

PubMed2001

Clostridial antibody response from injection-site lesions in beef cattle, long-term response to single or multiple doses, and response in newborn beef calves.

Experiments were conducted to compare clostridial antibody response of beef heifers that do and do not develop injection-site lesions, evaluate long-term antibody response of a single- and multiple-dose toxoid, and evaluate the ability of a clostridial toxoid to elicit an active antibody response in newborn calves. In Exp. 1, 37 weaned heifers were vaccinated (d 0) with a clostridial vaccine (Alpha-7, 2 mL, s.c.). Serum samples were collected on d 0, 28, 56, 84, and 112 to determine clostridial antibody titers. On d 28, heifers were visually inspected and palpated for injection-site lesions. The percentage of heifers that developed lesions was 64.9%. Lesioned heifers had elevated antibody titers for Clostridium chauvoei (CC) on d 28 (P < 0.08) and 84 (P < 0.07) compared with non-lesioned heifers. Clostridium sordellii (CS) and perfringens type D (CPD) antibody titers were greater in lesioned heifers than in non-lesioned heifers on d 28 and 56. In Exp. 2, long-term antibody response of Alpha-7 (A7) and Ultrabac 7 (UB7) was investigated in stocker heifers. The A7 heifers (n = 15) received one 2-mL vaccination (d 0), and the UB7 heifers (n = 15) received a 5-mL vaccination on d 0 and 28. Blood samples were collected on d 0, 28, 56, 84, 112, 140, and 180. Clostridium chauvoei, CPD, and Cl. novyi (CN) antibody titers from the A7 heifers were greater than those from the UB7 heifers on d 28. Due to the second UB7 injection, CC, CS, CN, and Cl. perfringens type C (CPC) antibody titers were greater in UB7 heifers than in A7 heifers on d 56. By d 112, titers were not different, and by d 140 all antibody titers were below detectable levels. In Exp. 3, 58 pregnant, mature, crossbred cows were vaccinated with A7 before calving. At birth, calves were carefully observed to ensure consumption of colostrum. Calves were blocked according to parturition date, and calves in each block were randomly allocated to receive A7 (s.c. at 3 +/- 3 d of age) or remain unvaccinated controls. Calves were bled at the time of vaccination (d 0) and on d 28, 56, 84, and 112. Antibody titers for CC, CPC, and CPD were elevated on d 0 and decreased throughout the experimental period (P < 0.01), but no titer differences (P > 0.10) were detected between treatment groups on any of the days sampled. These data indicated that antibody titers against clostridial diseases are enhanced when injection-site lesions develop. One injection of Alpha-7 seemed to provide the same length of protection as two injections of Ultrabac 7.

Animal Husbandry↗

PubMed1998

Polyethylene glycol 4000 attenuates adhesion formation in rats by suppression of peritoneal inflammation and collagen incorporation.

BACKGROUND: Postoperative separation of the peritoneal surfaces is a promising approach for the prevention of adhesion formation. Instillation of polyethylene glycol 4000 (PEG) was recommended as an appropriate method. METHODS: In a time-course study in rats, efficacy and mode of action of PEG was investigated. Adhesions were induced by crushing of the cecum. Sixty animals were randomly allocated to three control groups with intraperitoneal instillation of 5 mL 0.9% NaCl and to three therapy groups treated with 5 mL 20% PEG. After 3, 7, and 21 days, adhesion grade, intraperitoneal leukocytes, and collagen incorporation into the adhesion strands were evaluated. RESULTS: Administration of PEG resulted in a decrease of leukocytes by 43% (days 3 and 7), a reduction of the adhesion score by 85% (day 3), 77% (day 7), and 79% (day 21), and an impairment of collagen deposition by 54% (day 7) and 44% (day 21). CONCLUSIONS: Coating the peritoneal surfaces with PEG is a highly effective measure to suppress the fatal sequence of posttraumatic inflammation, formation of initial adhesions, and their subsequent organization to strong permanent adhesion strands.

Administration, Topical↗

PubMed2000

Reproductive efficiency of three estrus synchronization schemes comprising fixed-time insemination in dairy cows.

The objective of this field trial was to compare the odds of pregnancy at 25 days (P25) and at 60 days (P60), of embryonic death (ED) between 25 and 60 days, and of non-pregnant cows returning to heat 20-25 days after artificial insemination (AI). Three fixed-time insemination protocols involving combined administration of either double gonadotrophin-releasing hormone (GnRH) and prostaglandins (A) or GnRH, human chorionic gonadotrophin (hCG) and prostaglandins (B), or double treatment with prostaglandins (C) were used. Cows included in the trial were selected from five herds, comprising a total of 735 (herd size range 85-250, median 120) Holstein dairy cows. Animals used for the study were multiparous, 4-7 years of age, had expressed at least one overt postpartum heat, were between 60 and 120 days of lactation and had at least one palpable corpus luteum and no gross morphological anomalies of their reproductive tracts. They were randomly allocated to receive treatment A (n = 89), B (n = 93), or C (n = 65). Pregnancy of cows not observed in heat 18-24 days post AI was diagnosed by transrectal ultrasonography at 25-30 days and confirmed by rectal palpation at 60-75 days post AI. Those that were detected in heat in the normal period post AI were re-inseminated. No differences were detected among the three treatment groups concerning the odds of P25 (P = 0.5), P60 (P = 0.2) and ED (P = 0.13). In contrast, non-pregnant cows that were administered treatment A were less likely to exhibit estrous signs in the normal period post AI than those administered treatments B (P = 0.02) or C (P = 0.005).

Animals↗

PubMedDate not supplied

Evaluation of cross-protection afforded by a Salmonella Choleraesuis vaccine against Salmonella infections in pigs under field conditions.

This field study investigated the efficacy of a Salmonella Choleraesuis live vaccine (Argus SC) to reduce the number of infections with Salmonella. Twelve groups of about 380 pigs each were randomly allocated to either vaccination (V) or no vaccination (C). The vaccine was applied orally at 3 and 16 weeks. Forty pigs per group were blood sampled at 3, 10, 16, and 24 weeks to detect possible antibodies against Salmonella. The prevalence of Salmonella in the lymph nodes was the major variable. In the V groups, only 0.6% of the lymph nodes were positive, whereas 7.2% were positive in the C groups (p < 0.001). The percentage of seropositive pigs at 24 weeks (cut-off OD > 10) was 26% and 9% in the V and C groups, respectively (p < 0.001). The present study documented that vaccination with a live modified S. Choleraesuis vaccine is a useful tool to lower the prevalence of Salmonella in swine herds.

Animals↗