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PubMed2003

Physical training does not influence interictal LCMRglu in pilocarpine-treated rats with epilepsy.

This study evaluated, using local cerebral metabolic rates for glucose (LCMRglu) in 39 brain regions, whether physical training modifies the functional activity in rats with epilepsy. Most animals present seizures at rest rather than during exercise and LCMRglu was measured during the interictal phase of the chronic period of a pilocarpine model of epilepsy by the [14C]2-deoxyglucose (2DG) method. Wistar rats were allocated randomly into four groups: control rats (n=6), rats with epilepsy (n=6), trained control rats (n=6), and trained rats with epilepsy (n=6). Trained control rats did not show significant changes in LCMRglu when compared to control rats. LCMRglu was significantly higher in rats with epilepsy in the lateral posterior thalamic nucleus and in the visual cortex compared to control rats. Trained rats with epilepsy presented a higher LCMRglu than rats with epilepsy only in the inferior colliculus and auditory cortex. Increases in LCMRglu were also observed in the inferior colliculus of trained rats with epilepsy when compared to the trained control rats. Taken together, the results suggest that physical training does not influence interictal LCMRglu metabolism in most cerebral regions of rats with epilepsy.

Animals↗
PubMed2001

Development and de novo protein synthetic activity of bovine embryos produced in vitro in different culture systems.

In vitro matured (IVM) and fertilized (IVF) putative Day 1 zygotes (Day 0 = IVF) were allocated randomly to culture in formulations based on Synthetic Oviduct Fluid (SOF) medium and identified on the basis of their contrasting principal supplements, which were 10% v/v steer serum (SS; n = 558) or 4 mg/mL crystalline BSA (SBSA; n = 531) or 3 mg/mL polyvinyl alcohol (SPVA; n = 607) in 9 replicates. SBSA and SPVA also contained 10 microg/mL non-essential amino acids, while the former was further supplemented with 20 microL/mL essential amino acids and the latter with 0.5 mmol/L sodium citrate and 5 ng/mL epidermal growth factor. Zygotes were cultured in 20 microL drops (4 zygotes per drop) until Day 8 in an atmosphere of 5% CO2, 5% O2 and 90% N2 at 39 degrees C and droplets were renewed every 48 hours. The incidence of zygote cleavage was lower (P < 0.05) in SS (mean +/- SEM = 61 +/- 3%) than in SBSA (76 +/- 3%) but not in SPVA (72 +/- 4%) up to Day 3. The SPVA generated a lower yield of blastocysts on Day 7 (12 +/- 2%; P < 0.001) and by Day 8 (21 +/- 4%; P < 0.01) than did SS (33 +/- 3%; 40 +/- 3%) and SBSA (30 +/- 3%; 37 +/- 4%). Cell numbers (n) and diameters (d) of blastocysts on Day 8 were greater (P < 0.001; Replicates 1 to 5) in embryos from SBSA (n, 156 +/- 9; d, 203 +/- 4 microm) than in those from SS (n, 81 +/- 4; d, 177 +/- 3 microm) and SPVA (n, 76 +/- 5; d, 167 +/- 3 microm). Embryos produced in SS incorporated less 3H-phenylalanine into PCA-precipitable protein (replicates 6 to 9; log10 dpm = 3.03 +/- 0.04) than did embryos cultured in SBSA (3.21 +/- 0.03; P < 0.001) or in SPVA (3.14 +/- 0.03; NS). In conclusion, blastocyst yield was poor in SPVA, but the embryos had metabolic activities similar to those of embryos produced in SBSA. Blastocyst yields from SS were not compromised but their capacity for de novo protein synthesis was reduced significantly.

Animals↗
PubMed2001

Fertilization and embryo recovery rates in superovulated chios ewes after laparoscopic intrauterine insemination.

Forty superovulated dairy ewes of the Greek Chios breed were used in an experiment to evaluate the efficiency of laparoscopic intrauterine insemination on fertilization and embryo recovery rates as well as embryo quality. Estrus was synchronized by intravaginal progestagen impregnated sponges and superovulation was induced by administration of 8.8 mg o-FSH i.m. following a standard 8 dose protocol. A small volume (0.3 mL) of diluted fresh ram semen was deposited in each uterine horn 24 to 28 h after onset of the estrus by a laparoscopic technique. The animals were allocated randomly into two groups (Group A and B) of 20 animals each. In Group A, embryos were recovered 18 to 24 h after the intrauterine insemination and in Group B on Day 6. The average number of corpora lutea was 12.8 +/- 1.2 and 11.5 +/- 1.1 (+/- SEM); the overall embryo recovery was 66.4% and 57% and the percentage of recovered fertilized ova was 81% and 82.8% in Groups A and B, respectively. More fertilized ova were collected per ewe from Group A (P < or = 0.1). Results indicated that in Chios breed, superovulation using homologous FSH combined with laparoscopic AI leads to good ovarian response with satisfactory results in fertilization, embryo recovery and quality of embryos. This could lead to improved and more efficient methods for obtaining large numbers of high quality oocytes and embryos for embryo transfer programs which could contribute to genetic improvement and increase of the population size.

Animals↗
PubMed2000

Efficacy of moxidectin equine oral gel against endoscopically-confirmed Gasterophilus nasalis and Gasterophilus intestinalis (Diptera: Oestridae) infections in horses.

A 3 m, video gastroscope was used to screen 47 horses suspected of being naturally infected with equine bot larvae. 17 of 47 (36.2%) candidate horses harbored Gasterophilus nasalis larvae in the proximal duodenum and 46 of 47 (97.9%) had G. intestinalis larvae in the stomach. All horses infected with G. nasalis had concurrent infections with G. intestinalis. 14 horses with dual infections were allocated randomly to two treatment groups. Seven horses in Group 1 received 2% moxidectin oral gel once at a dosage of 0.4 mg/kg bodyweight (BW), and seven horses in Group 2 were untreated controls. 14 days after treatment, all horses were necropsied and the stomach and proximal duodenum harvested from each. Bot larvae were recovered, identified to species and instar, and counted. At the label dosage, moxidectin oral gel was 100 and 97.6% effective (P < 0.05) against third-instar G. nasalis and G. intestinalis, respectively. In addition to demonstrating the boticidal efficacy of moxidectin, this trial illustrated that gastroscopy/duodenoscopy is a feasible method for confirming infections with different species of bot larvae in the horse.

Administration, Oral↗
PubMed2005

Anthelmintic activity of extracts of Spondias mombin against gastrointestinal nematodes of sheep: studies in vitro and in vivo.

This study was carried out to validate the efficacy of Spondias mombin, used locally as an anthelmintic, and to standardize the effective dose of the plant extract required for worm control in livestock. In vitro and in vivo studies were conducted to determine the direct anthelmintic effect of ethanolic and aqueous extracts of S. mombin towards different ovine gastrointestinal nematodes. A larval development assay (LDA) was used to investigate the in vitro effect of extracts on strongyle larvae. Another study was conducted in vivo to evaluate the therapeutic efficacy of the extracts administered orally at dose rates of 125, 250, 500 mg/kg to sheep naturally infected with gastrointestinal nematodes. Twenty sheep were selected on the basis of positive faecal egg counts (750 epg). The sheep were allocated randomly to a non-medicated control group (A) or to groups given 125 mg/kg (B), 250 mg/kg (C) or 500 mg/kg (D) of extract, respectively. Sheep in groups B-D were given extracts orally on two days. Individual faecal egg counts were performed on days 0, 3, 6, 9 and 12. The presence of S. mombin extracts in in vitro cultures of larvae decreased the survival of L3 larvae. The LC50 of the aqueous extract of S. mombin was 0.907 mg/ml, while the LC50 of the ethanolic extract was 0.456 mg/ml. This difference in LC50 was statistically significant (p > 0.05). The mean percentage faecal egg reduction of sheep drenched with 500 mg/kg S. mombin extracts was 15.0%, 27.5%, 65.0%, 65.0%, 100.0% against Haenmonchus spp., Trichostrongylus spp., Oesophagostomunm spp., Strongyloides spp. and Trichuris spp. respectively, on day 12. Extracts of S. mombin could find application in the control of helminths in livestock.

Anacardiaceae↗
PubMed1999

Experimental study of the effect of intraperitoneal heparin on tumour implantation following laparoscopy.

BACKGROUND: Conclusions drawn from clinical reports of port site metastases following laparoscopic resection of intra-abdominal malignancy are now supported by a burgeoning experimental literature which suggests that laparoscopy promotes tumour metastasis to wounds. This study investigated the effect of intraperitoneal blood and heparin on the incidence of tumour cell implantation and port site metastasis. METHODS: Twenty-four Dark Agouti rats underwent laparoscopy with carbon dioxide insufflation and the instillation of a tumour cell suspension and/or blood into the peritoneal cavity. Rats were allocated randomly to one of the following study groups (six rats per group): (1) controls; (2) intraperitoneal blood (2 ml blood introduced from a syngeneic donor rat); (3) intraperitoneal heparin; (4) intraperitoneal blood and heparin. Rats were killed 7 days after the procedure, and the peritoneal cavity and port sites were examined for the presence of tumour. RESULTS: Tumour implantation and port site metastases were reduced by the intraperitoneal administration of heparin, but increased by the presence of intraperitoneal blood. CONCLUSION: The results of this study suggest that tumour implantation following laparoscopy is promoted by the presence of intraperitoneal blood and that this effect may be reduced by the use of intraperitoneal heparin.

Animals↗
PubMed2002

Calcium sulphate as a bone substitute for various osseous defects in conjunction with apicectomy.

AIM: The purpose of this study was to investigate the effect of calcium sulphate on various osseous defects when used in conjunction with apicectomy. METHODOLOGY: Mandibular third and fourth premolars of 11 beagle dogs were used. After root-canal treatment and apicectomy, three types of osseous defects were prepared on both sides of the mandible as follows: type 1, osseous defect communicating with the gingival sulcus: type 2, large osseous defect including two roots; type 3, 'through and through' osseous defect. The experimental side was allocated randomly, and the osseous defects were filled with medical grade calcium sulphate. The defects on the opposite side were left unfilled as controls. The dogs were sacrificed at 8 and 16 weeks postoperatively. Undemineralized sections were obtained and examined histomorphometrically. RESULTS: In type 1 defects, bone was not observed on the buccal side of the root on either experimental or control side at 8 and 16 weeks. In both type 2 and 3 defects, bone volume/tissue volume (BV/TV) values on the experimental side were significantly higher than those on the control side (P < 0.01), and mineral apposition rate (MAR) values on the experimental side were significantly higher than those on the control side (P < 0.01). CONCLUSIONS: The use of calcium sulphate was effective in bone regeneration on both large osseous defects and 'through and through' osseous defects. It was less effective in osseous defects communicating with the gingival sulcus.

Alveolar Bone Loss↗
PubMed1996

The effect of cottonseed condensed tannins on the ileal digestibility of amino acids in casein and cottonseed kernel.

The effect of adding cottonseed hulls to casein- and cottonseed-kernel-based diets on the apparent and true ileal digestibility of N and amino acids, and the proportion of this effect accounted for by condensed tannin (CT), were determined using the growing rat. Sixty rats were allocated randomly to ten semipurified diets, containing either casein (four diets) or purified unheated solvent-extracted cottonseed kernel (six diets) as the sole protein source, with Cr2O3 added as an indigestible marker. Two of the casein diets contained no hulls whilst the remaining two diets contained 70 g cottonseed hulls/kg. Two of the cottonseed-kernel-based diets contained no hulls, with two containing 23 g hulls/kg and the remaining two containing 46 g hulls/kg. For each pair of diets, PEG was either included or excluded. The effect of CT was quantified by comparing control rats (-PEG; CT acting) with PEG-supplemented rats (+PEG; CT inactivated) at each level of dietary hulls. The rats were given their respective experimental diets for 14 d. Each rat was given the food ad libitum for 10 min hourly from 08.00 to 18.00 hours. On day 14, samples of digesta were collected at death from the terminal 150 mm of ileum at 7 h from the first meal. Apparent and true ileal digestibilities were calculated for DM, N and the individual amino acids. The principal finding was that the inclusion of hulls depressed the apparent and true ileal digestibilities of N and amino acids, but with the response differing between diets. With the casein-based diet the mean apparent and true ileal amino acid digestibilities were significantly depressed from 0.89 and 0.96 to 0.85 and 0.92 respectively, by the inclusion of 70 g hulls/kg in the diet, and addition of PEG then restored these to 0.89 and 0.95. All of the depression could be explained by the CT content of the hulls. However, with the cottonseed-kernel-based diet the responses fell into three categories. The apparent and true ileal digestibilities of the essential amino acids cystine and methionine were not affected by hull addition, ileal digestibilities of leucine, isoleucine, lysine, threonine and valine were markedly depressed by hull addition with approximately 50% of the depression being explained by CT, whilst the ileal digestibilities of histidine, arginine and phenylalanine were depressed by hull addition but little or none of this effect could be explained by CT. Thus the effect of hulls on protein digestion clearly differed with source of protein. With the cottonseed-kernel-based diet it seems that components of the hulls other than CT also depressed the apparent and true ileal digestibilities of N and amino acids. The identity of these components is unknown.

Amino Acids↗
PubMed1984

Sore throat after intubation of the trachea.

Eighty female patients were allocated randomly to groups, divided in three ways, to investigate the effects of using cuffed p.v.c. v. red rubber tracheal tubes, intermittent adjustment of the cuff volume, and humidification of inspired gases on the incidence and severity of sore throat after tracheal intubation. In addition, the influence of the anaesthetist's participation in the trial was studied by assessing sore throat in a further 60 female patients where the anaesthetists were unaware of the trial. There were no significant differences between any of the groups despite using three sensitive methods of assessment. In terms of the simple discrimination between "sore throat" and "no sore throat" the 95% confidence limits of the differences of incidence were generally +/- 15-20%. If there are any real differences produced by these changes, and if any of them were as large as 15% then, to show with 95% confidence that any difference is at least 10%, would require a trial involving about 1400 patients. Retrospective analysis of the results showed no difference between patients who received suxamethonium and those who did not.

Adult↗
PubMed1991

Effect of PaCO2 on cerebral blood flow distribution during halothane compared with isoflurane anaesthesia in the rat.

In order to examine anaesthetic effects on the distribution of cerebral blood flow (CBF) during normo- and hypocapnia, male adult Sprague-Dawley rats were allocated randomly to four groups in a 2 x 2 factorial design, using PaCO2 value and anaesthetic agent as between-group factors. Animals were anesthetized with either 1.38% isoflurane (inspired) or 1.05% halothane (inspired) and the lungs ventilated mechanically at either normocapnia (PaCO2 5.1-5.6 kPa) or hypocapnia (PaCO2 3.1-3.3 kPa) for 1 h. CBF was measured using 14C-iodoantipyrine autoradiography. Local CBF in selected cortical and subcortical regions of interest and area-weighted mean global CBF were calculated. Data were compared by analysis of variance. Normocapnic (mean (SE] CBF for halothane (n = 6) and isoflurane (n = 7) was 120 (8) ml/100 g min-1 (PaCO2 5.6 (0.49) kPa) and 117 (9) ml/100 g min-1 (PaCO2 5.4 (0.5) kPa), respectively. Hypocapnic CBF for halothane (n = 6) and isoflurane (n = 6) was 82 (7) ml/100 g min-1 (PaCO2 3.3 (0.12) kPa) and 82 (6) ml/100 g min-1 (PaCO2 3.2 (0.12) kPa), respectively. Hypocapnia reduced global CBF for both groups by 30% (P less than 0.001), but there was no difference between anaesthetic agents (P greater than 0.8). Hypocapnia decreased CBF in all local structures examined. Although subcortical structures had similar CBF at both normocapnia and hypocapnia, CBF in three cortical samples was greater (P less than 0.05) in both the normocapnic and hypocapnic halothane groups than the corresponding isoflurane groups. The CBF reactivity to changes in PaCO2 was similar for both agents (approximately 2 ml/100 g min-1 mm Hg). (ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Inhalation↗
PubMed1992

Differential effects of vecuronium on diaphragm and geniohyoid muscle in anaesthetized dogs.

We have examined the sensitivity of the geniohyoid, an upper airway dilating muscle, to vecuronium in 12 anaesthetized dogs undergoing mechanical ventilation of the lungs and compared it with that of the diaphragm. Dogs were allocated randomly to two groups: pentobarbitone alone (group 1, n = 7); pentobarbitone combined with 0.2 MAC (0.44%) of enflurane anaesthesia (group 2, n = 5). Supramaximal single twitch stimulations (0.1 Hz) were applied to the phrenic nerves in the upper thorax and the geniohyoid branches of the hypoglossal nerves at the neck. The evoked responses were assessed by the transdiaphragmatic pressure (Pdi) and the isometric force of the geniohyoid muscles (Tgh) until complete recovery of these variables after i.v. administration of vecuronium 0.02 mg kg-1. In both groups, the magnitude of the depression of twitch response was greater and time required to reach control amplitude was longer in the geniohyoid than the diaphragm. The depression of Tgh was significantly greater in group 2 than in group 1, whereas no change was observed in Pdi between the two groups. We conclude that the geniohyoid is more sensitive to vecuronium than the diaphragm and the differential effects of vecuronium are facilitated by a low concentration of enflurane.

Anesthesia, Inhalation↗
PubMed1995

Dexmedetomidine does not modify the neuromuscular blocking action of vecuronium in the anaesthetized rat.

Dexmedetomidine is a new alpha 2 adrenergic agonist anaesthetic adjuvant. In animal studies, dexmedetomidine produced muscle flaccidity and prevented opioid-induced muscle rigidity, apparently via a central mechanism. The effect of dexmedetomidine on the neuromuscular junction or on non-depolarizing neuromuscular block during anaesthesia has not been reported. We have studied in the anaesthesized rat, the effects of dexmedetomidine on vecuronium-induced twitch depression. Wistar rats (n = 35) were anaesthetized and their lungs ventilated to maintain normocapnia. An infusion of vecuronium of 2.3 (SEM 0.1) micrograms kg-1 min-1 produced a stable twitch height (T1) depression of the tibial nerve of 53 (2)% of control in all groups. Rats were allocated randomly to receive either saline or dexmedetomidine 10, 30 or 100 micrograms kg-1 i.v. and T1 height was measured continuously for 60 min. Dexmedetomidine did not significantly affect T1 height during the first 30 min of infusion. At later times there were minor differences between groups. With cessation of the infusion of vecuronium, T1 height recovered rapidly to normal in all groups. These data suggest that the neuromuscular blocking properties of dexmedetomidine are unlikely to be produced by action at the neuromuscular junction.

Action Potentials↗
PubMed1995

Cardiovascular responses to graded doses of three catecholamines during lactic and hydrochloric acidosis in dogs.

We have studied the cardiovascular effects of incremental doses of three catecholamines in dogs subjected to lactic (LAC) and hydrochloric (HCl) acidosis. Fifty-four dogs were allocated randomly to one of three groups: control, LAC and HCl acidosis (n = 18 each group). In the acidotic models, 2 mol litre-1 of lactic acid (4 ml kg-1 h-1) or 2 mol litre-1 of HCl (1 ml kg-1 h-1) was infused i.v. until arterial pH was reduced to 7.00 +/- 0.1. Within each group, six dogs received one of three different drugs in logarithmically incremental doses: adrenaline 0.1, 0.2, 0.4, 0.8, 1.6, 3.2 micrograms kg-1 min-1, noradrenaline 0.1, 0.2, 0.4, 0.8, 1.6, 3.2 micrograms kg-1 min-1 and dobutamine 5, 10, 20, 40, 80, 160 micrograms kg-1 min-1. Cardiovascular variables were monitored, with periodic measurements of plasma electrolyte and lactate concentrations. The pH reduction induced by HCl or lactic acid was associated with a statistically significant increase in mean pulmonary arterial pressure (MPAP), prominent especially in the LAC group where MPAP increased from mean 18 (SD 5) to 27 (6) mm Hg. In the acidotic models, the reduction in myocardial responsiveness to adrenaline or noradrenaline was more prominent than that for the control for corresponding doses of drugs. In the LAC group mean cardiac index decreased significantly from 5.2 (1.8) to 2.2 (0.7) litre min-1 m-2 after infusion of adrenaline 3.2 micrograms kg-1 min-1 and decreased from 5.1 (1.1 to 2.4 (0.9) litre min-1 m-2 after infusion of noradrenaline 3.2 micrograms kg-1 min-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis↗
PubMed1995

Testing the porphyrinogenicity of propofol in a primed rat model.

We evaluated the porphyrinogenicity of propofol in a rat model. After a pilot study had been conducted to determine an optimal dose, 48 fasting male Sprague-Dawley rats were allocated randomly to six groups. The animals in groups 1-3 received saline i.p. In groups 4-6, the animals were given allylisopropylacetamide (AIA). Twelve hours later, animals in groups 1 and 4 received saline, groups 2 and 5 were given propofol 150 mg kg-1 i.p., followed by 75 mg kg-1 3 h later, and groups 3 and 6 received phenobarbitone 50 mg kg-1 i.p. and 25 mg kg-1 i.p. The animals were anaesthetized and killed 3 h after the second drug bolus and we measured the concentration of cytochrome P450, total porphyrin content and the activity of delta-aminolaevulinic acid synthase (ALAS) in the liver. Urinary delta-aminolaevulinic acid (ALA) and porphobilinogen (PBG) concentrations were measured. Analysis of variance and the t test with Bonferroni's correction were used to compare data. The hepatic cytochrome P450 concentration in the non-primed groups varied from 28.1 to 31.1 nmol g-1; administration of AIA decreased this to 20.1-20.9 nmol g-1. Total hepatic porphyrins were between 0.78 and 1.22 nmol g-1 in the non-primed groups and between 2.71 and 3.54 nmol g-1 in the AIA-primed groups. Hepatic ALAS activity was 29.2 and 35.5 nmol h-1 g-1 in groups 1 and 2. In the primed saline group, ALAS activity was measured at 134.5 nmol h-1 g-1.(ABSTRACT TRUNCATED AT 250 WORDS)

5-Aminolevulinate Synthetase↗
PubMed1999

Relaxant effect of propofol on the airway in dogs.

Propofol has been suggested to produce airway relaxant effects in vivo, although the mechanism is unclear. We have evaluated the bronchodilating effect of propofol using a direct visualization method with a superfine fibreoptic bronchoscope. We studied 21 mongrel dogs anaesthetized with pentobarbital 30 mg kg-1 i.v. and pancuronium 0.2 mg kg-1 h-1. The animals were allocated randomly to one of three groups (n = 7 in each): propofol group, atropine-propofol group and histamine-propofol group. The trachea was intubated using a tracheal tube that had a second lumen for insertion of the bronchoscope to monitor continuously bronchial cross-sectional area (BCA). BCA was measured using the NIH Image program. In the propofol group, dogs were given the following doses of propofol at 10-min intervals: 0 (saline), 0.2, 2.0 and 20 mg kg-1 i.v. In the atropine-propofol group, saline, atropine 0.2 mg kg-1 and propofol 20 mg kg-1 were given at 10-min intervals. In the histamine-propofol group, bronchoconstriction was elicited with histamine 10 micrograms kg-1 and 500 micrograms kg-1 h-1 until the end of the experiment. Thirty minutes after the start of infusion of histamine, propofol (0, 0.2, 2.0 and 20 mg kg-1) was administered. Changes in BCA were expressed as percentage of basal area. Histamine decreased BCA by 39.2 (SEM 5.4%). Propofol increased significantly basal and histamine-decreased BCA in a dose-dependent manner by 18.4 (4.5%) and 15.8 (4.9%), respectively after 20 mg kg-1 i.v. However, propofol following atropine i.v. did not increase BCA (129.9 (8.2)% after atropine vs 125.7 (8.9)% after propofol). Therefore, the relaxant effect of propofol may be a result of reduction in vagal tone.

Anesthetics, Intravenous↗
PubMed2000

Fruits and vegetables increase plasma carotenoids and vitamins and decrease homocysteine in humans.

Observational epidemiologic studies have shown that a high consumption of fruits and vegetables is associated with a decreased risk of chronic diseases. Little is known about the bioavailability of constituents from vegetables and fruits and the effect of these constituents on markers for disease risk. Currently, the recommendation is to increase intake of a mix of fruits and vegetables ("five a day"). We investigated the effect of this recommendation on plasma carotenoids, vitamins and homocysteine concentrations in a 4-wk dietary controlled, parallel intervention study. Male and female volunteers (n = 47) were allocated randomly to either a daily 500-g fruit and vegetable ("high") diet or a 100-g fruit and vegetable ("low") diet. Analyzed total carotenoid, vitamin C and folate concentrations of the daily high diet were 13.3 mg, 173 mg and 228.1 microg, respectively. The daily low diet contained 2.9 mg carotenoids, 65 mg vitamin C and 131.1 microg folate. Differences in final plasma levels between the high and low group were as follows: lutein, 46% [95% confidence interval (CI) 28-64]; beta-cryptoxanthin, 128% (98-159); lycopene, 22% (8-37); alpha-carotene, 121% (94-149); beta-carotene, 45% (28-62); and vitamin C, 64% (51-77) (P < 0.05). The high group had an 11% (-18 to -4) lower final plasma homocysteine and a 15% (0.8-30) higher plasma folate concentration compared with the low group (P < 0.05). This is the first trial to show that a mix of fruits and vegetables, with a moderate folate content, decreases plasma homocysteine concentrations in humans.

Adult↗
PubMed1993

Heparin does not stimulate coronary-collateral growth in a canine model of progressive coronary-artery narrowing and occlusion.

To investigate the possible effect of heparin on coronary-collateral growth, dogs were instrumented chronically with a left circumflex (LCF) flow probe, an ameroid constrictor, a balloon occluder, and left and right atrial and aortic catheters. Collateral blood flow was measured at least weekly or when the coronary artery was occluded. Animals were allocated randomly to a control or treatment group. The latter received a continuous right-atrial infusion of a heparin solution at a rate of 2 to 3 ml/hour and a concentration adjusted daily to increase the activated clotting time to approximately 3 times the pre-drug level. After LCF occlusion, coronary-collateral flow was measured during exercise. There was no difference in time to LCF occlusion in the anticoagulated dogs. Furthermore, neither the rate of collateral development, the magnitude of collateral flow shortly after spontaneous LCF occlusion, nor the degree of collateral vascular reserve during exercise was different in the two groups. Therefore, in this model of coronary obstructive disease, heparin does not accelerate coronary-collateral development.

Analysis of Variance↗
PubMed1994

The effect of adenosine-induced hypotension on systemic and splanchnic hemodynamics during halothane or sevoflurane anesthesia in the rat.

BACKGROUND: It has been suggested that the liver may be at risk for ischemic damage during adenosine-induced hypotension. This notion, however, is somewhat inconsistent with the understanding that adenosine is a powerful vasodilator of the splanchnic circulation. To help clarify the effect of adenosine-induced hypotension on splanchnic hemodynamics, we studied the systemic and splanchnic hemodynamic responses to adenosine, both alone and in the presence of halothane or sevoflurane. METHODS: Systemic and splanchnic hemodynamics were determined during the infusion of adenosine in 36 rats allocated randomly to one of three study groups: (1) awake, (2) halothane anesthesia (1.0 MAC), or (3) sevoflurane anesthesia (1.0 MAC). Adenosine was infused at a rate sufficient to decrease the mean arterial pressure by 35-38% from awake control values. Cardiac output and organ blood flows were measured using the radiolabeled microsphere technique. RESULTS: Adenosine infusion produced stable hypotension of rapid onset due to a reduction in systemic vascular resistance. Stroke volume increased, but cardiac output remained unchanged in the awake and sevoflurane groups because of a decrease in heart rate. Infusion of adenosine during halothane anesthesia increased cardiac output enough to compensate for the decrease in cardiac output due to halothane alone. In the splanchnic circulation, there was an increase in portal tributary (42%, P < 0.01) and hepatic arterial (38%, P < 0.05) blood flows during adenosine infusion in awake rats. This resulted in an overall increase in total liver blood flow (42%, P < 0.01). Halothane anesthesia was associated with a decrease in portal tributary blood flow (28%, P < 0.05). In contrast, sevoflurane anesthesia was associated with an increase in hepatic arterial flow (35%, P < 0.05) but with no change in portal tributary blood flow. During halothane anesthesia, adenosine infusion increased portal tributary (90%, P < 0.01) and hepatic arterial (37%, P < 0.05) blood flows, thereby increasing total liver blood flow to values similar to those in awake adenosine-infused rats. During sevoflurane anesthesia, adenosine infusion increased portal tributary blood flow (48%, P < 0.01), but hepatic arterial blood flow did not increase beyond the values observed during sevoflurane anesthesia alone. CONCLUSIONS: These findings demonstrate that adenosine is a potent vasodilator of portal tributary and hepatic arterial vasculature in the rat and that the splanchnic hemodynamic effects of adenosine predominate over those of halothane and sevoflurane.

Adenosine↗