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Biomedical subjects

T Hassan

Publications and source records attributed to T Hassan.

At least 55 records · Page 3Linked to original sources
PubMed1986

Electrophysiologic actions of pirmenol in dogs with recent myocardial infarction.

The electrophysiologic actions of pirmenol, an investigational class I antiarrhythmic agent, were evaluated in eight anesthetized dogs, 5 to 10 days after anterior myocardial infarction. Before administration of the drug, programmed ventricular stimulation failed to initiate nonsustained or sustained ventricular tachyarrhythmias (VT) in any of the postinfarction dogs. After the cumulative administration of 2.5, 5.0, and 10.0 mg/kg pirmenol, programmed stimulation initiated sustained VT in six of the eight postinfarction dogs tested, with one additional dog responding with reproducible nonsustained VT (15 to 20 monomorphic complexes) after pirmenol administration. Only one of eight postinfarction dogs tested remained noninducible throughout the pirmenol dosing schedule. Administration of pirmenol tended to increase ventricular excitation thresholds, relative (p less than 0.05 after 10 mg/kg) and effective refractory periods in ischemically injured ventricular myocardium, and increased the difference or disparity in relative (p less than 0.05 after 5.0 and 10.0 mg/kg) and effective (p less than 0.01 after 2.5, 5, and 10, mg/kg) refractory periods between ischemically injured and normal noninjured ventricular myocardium. These findings suggest a potential for the provocation or aggravation of ventricular arrhythmias by pirmenol in the setting of recent myocardial infarction.

Animals↗
PubMed1986

Effects of furazolidone on some reproductive hormones during oestrous cycle in the goat.

In non-pregnant goat luteolysis is characterized by a decline in peripheral plasma progesterone level and increased peripheral plasma concentrations of testosterone (T) and 5 alpha-dihydrotestosterone (DHT). Daily oral doses of furazolidone (80 mg/kg) between days 10 and 16 delayed luteolysis and suppressed both the decline in progesterone concentrations and the increase in T and DHT level.

Animals↗
PubMed1986

The effect of furazolidone on some clinical and biochemical parameters in goats.

Furazolidone (FZ) administered to goats orally at the recommended therapeutic dose (10 mg/kg body weight for 5 days) resulted in significant decreases in heart rate, pulse rate, and rectal temperature. No change was observed in respiratory rate or body weight, although a tendency towards a decrease in the latter was observed. An increase in the number of the erythrocytes was found. FZ also produced significant decreases in the pseudocholinesterase activity and plasma concentrations of total protein and ascorbic acid. A significant increase in the adrenal cholesterol concentration was observed while the weight of adrenal glands and their ascorbic acid concentration and content were unaffected. No significant histopathological changes were observed in treated goats.

Adrenal Glands↗
PubMed1986

Neuromuscular blocking activity of a crude aqueous extract of Ipomoea fistulosa.

The rat phrenic nerve hemidiaphragm and chick biventer-cervicis preparations were used to investigate the effect of a crude aqueous extract of Ipomoea fistulosa. Electrically-induced skeletal muscle twitches of the hemidiaphragm were blocked by the extract and by tubocurarine. The anticholinesterase, physostigmine, intensified the blockade by the extract. The extract produced contracture of the chick biventer-cervicis preparation. It is suggested that the extract possesses neuromuscular blocking activity of a depolarizing nature.

Animals↗
PubMed1986

Some observations on the toxicosis of isometamidium chloride (samorin) in camels.

Healthy camels were experimentally infected with Trypanosoma evansi and then treated with isometamidium chloride (samorin) at single intravenous doses of 0.5 or 1.0 mg/kg. Five to 10 min after the drug administration, the camels at both dosages showed lacrimation, salivation, trembling, restlessness, frequent urination and defecation, followed by diarrhea. Moreover, the camels at the higher dose showed an unsteady gait for about an hour with hindleg weakness and walking backward. The animals fell to the ground, laid on their sides, and bent their necks into an "S" shaped curve. Three hours after the drug administration all the animals stood up and remained quiet. The treatment increased the concentration of plasma ammonia and total protein. No significant change was found in the plasma bilirubin concentration. Two hours after treatment, the activity of plasma cholinesterase was significantly reduced. The enzyme activity recovered 24 h after drug administration, but was still significantly below the control value. The treatment did not produce statistically significant changes in the hemogram of the infected camels. The results suggest that the drug should not be used clinically against T evansi infection due to its low margin of safety. If the drug is to be used at all in camels, pretreatment with an anticholinergic agent might be considered.

Animals↗
PubMed1986

The cytochromes P-450 concentrations in microsomes of liver, kidney and duodenal mucosa of the camel, sheep and goat.

The concentration of microsomal cytochromes P-450, and of protein in the homogenate, cytosol and microsomes were measured in the liver, kidney and duodenal mucosa of healthy well-fed male and female camels, sheep and goats. For comparison, data from the liver of male and female rats were also obtained. The protein concentrations in the tissues of adult animals were broadly similar in the four species. The concentration of cytochromes P-450 was highest in the liver, followed by the kidney, then the duodenal mucosa in all the species. No cytochromes P-450 were detected in the tissues of immature (less than 1 mo) male goats, whereas the female goat had the highest concentrations of these enzymes in the liver and kidney when compared with the respective tissues in the other species studied. Males had higher activity of cytochromes P-450 than females in the three tissues, except in the duodenal mucosa of sheep, where males had lower activity than females. In camel liver and sheep kidney, the amount of cytochromes P-450 were similar in the two sexes. The present results suggest that the mature female goat is the species best equipped to handle xenobiotics which are detoxified by the cytochromes P-450 and other drug metabolizing enzymes in diseased or malnourished animals is suggested as these two conditions are known to modify drug metabolizing enzymes.

Animals↗
PubMed1985

Furazolidone concentrations in plasma, milk and some tissues of Nubian goats.

The concentrations of furazolidone (FZ) in plasma and milk were measured in goats treated orally with the drug at a dose of 10 mg kg-1 daily for 5 days. The maximum plasma concentrations obtained were 1.57 +/- 0.52 micrograms ml-1 (n = 5) 8 h after the first dose, and 2.13 +/- 0.11 micrograms ml-1 (n = 4) 6 h after the fifth dose. The maximum milk concentration was 0.88 +/- 0.32 micrograms ml-1 (n = 4) 8 h following the administration of a single dose. Using a colorimetric method, FZ was not detectable in goats' liver or muscle after the recommended therapeutic dose (10 mg kg-1, 5 days). However, using an HPLC method, the drug was detected 24 h after the treatment in the gluteal muscle and liver at concentrations of 0.26 +/- 0.01 microgram g-1 (n = 5) and 0.10 +/- 0.02 microgram g-1 (n = 5), respectively. The drug concentrations decreased significantly (P less than 0.05-0.01) at 3, 5 and 7 days after treatment, and no measurable concentrations were found after 10 days.

Animals↗
PubMed1985

The effect of niclofolan on desert sheep experimentally infected with immature Fasciola gigantica.

Eight desert sheep were each infected orally with 500 metacercariae of Fasciola gigantica and, after 4 weeks, four of the animals were given niclofolan orally at the recommended therapeutic dose rate of 7 mg/kg, the other four remaining as controls. One week later, the animals were slaughtered and the fasciocidal effect of the drug was evaluated on the basis of worm burden, haemogram, some plasma constituents, and gross and histopathological lesions of the liver, as indicators of efficacy. The treatment was found to be ineffective, the degree of infection remaining the same as in the untreated control group. The experiment was repeated using eight infected sheep: four were given the drug orally at a dose rate of 10.5 mg/kg, i.e., 1.5 times the recommended dose; and the same parameters were measured as described above. The drug failed to cure the infected sheep, and caused depression, anorexia and weakness. In a third experiment six sheep were infected as before and three were treated with niclofolan by deep i.m. injection at the recommended therapeutic dose of 2 mg/kg. A week later the animals were killed and examined as before. The drug was effective in treating the infection and produced no untoward effects except for transient signs of pain at the site of injection. It seems possible that the oral dose, unlike the i.m. dose, of niclofolan is not absorbed and/or metabolized sufficiently to prevent elimination of the infection.

Animals↗
PubMed1985

Some effects of imidocarb in goats.

Clinically normal Nubian goats were given the antiprotozoal drug imidocarb at single intramuscular doses of 6, 12, 18 and 24 mg/kg, and the various clinical, biochemical and pathological manifestations were recorded. At a dose of 6 mg/kg the drug produced no change in any of the parameters studied. At higher doses, the drug produced dose dependent changes which included increased heart and respiratory rates, increased defaecation, urination, depression, incoordination of movement, weakness of the hindlegs, recumbency, and finally death. Just prior to death, there was a significant decrease in the number of erythrocytes, and in packed cell volume, and haemoglobin concentration. In plasma there was an increase in the activity of aspartate transaminase, urea and creatinine concentrations and inhibition of cholinesterase activity. The main histopathological changes were associated with hepatic and renal damage. Three goats were pre-treated with atropine sulphate (1 mg/animal) and after one hour given imidocarb intramuscularly at a dose of 12 mg/kg. The changes were similar but much less severe when compared with those in animals given imidocarb alone at the same dose.

Animals↗
PubMed1984

Preliminary pharmacokinetic study of isometamidium chloride in camels.

Isometamidium chloride was given to camels at a single intravenous dose rate of 0.5 or 1 mg kg-1 and the plasma drug concentration measured spectrophotometrically at frequent intervals for up to 48 hours. Isometamidium chloride concentrations were found to be 9.8 +/- 0.2 and 8.7 +/- 0.2 micrograms ml-1 half an hour after treatment with 1 and 0.5 mg kg-1, respectively, and 1.7 +/- 0.3 and 0.7 +/- 0.3 micrograms ml-1 after 24 hours. No measurable drug concentration was found 48 hours after dosing.

Animals↗
PubMed1984

Toxicity of furazolidone to Nubian goats.

Male Nubian goats were given furazlidone orally at daily doses of 40, 80, 160 and 320 mg/kg for up to 10 days. Animals given 160 and 320 mg/kg became anemic, and showed anorexia, hyperexcitability, uneasiness , backward walking, locomotory disturbances and circling. These animals died within 5 to 7 days of treatment. Postmortem examination showed mild congestion in brain, and fatty change in liver and kidneys. There was histopathological evidence of hepatic and renal damage, and some necrosis in brain and adrenals. Biochemical examination of serum confirmed the presence of hepatic and renal damage. Goats given furazolidone at daily doses of 40 and 80 mg/kg showed similar signs as above, but to a lesser degree. They were killed at the end of the experiment (10 days). The signs of furazolidone intoxication resembled those of cerebrocortical necrosis (thiamine deficiency in ruminants). Therefore, thiamine (100 mg/animal) was injected iv daily to goats receiving 320 mg furazolidone/kg. The vitamin ameliorated the severity of the drug toxicity.

Animals↗
PubMed1970

Adrenoceptors of the chick rectum.

1. The aim of the investigation was to determine whether the adrenoceptors of the chick rectum preparation complied with Ahlquist's classification; phentolamine (0.1 mug/ml) and propranolol (0.05 mug/ml) were used as specific antagonists of alpha- and beta-adrenoceptors, respectively.2. Propranolol antagonized phenylephrine, isoprenaline and noradrenaline in the chick rectum preparation, although according to Ahlquist's classification phenylephrine stimulates alpha-adrenoceptors selectively.3. In the presence of propranolol, phenylephrine and noradrenaline produced small residual relaxations of the chick rectum preparation which were blocked by phentolamine. In the absence of propranolol, however, phentolamine did not antagonize relaxations to phenylephrine, isoprenaline or noradrenaline.4. The adrenoceptors of the guinea-pig colon preparation compiled with Ahlquist's classification in that they were like those generally present in intestine.

Adrenergic alpha-Agonists↗
PubMed1969

A hyoscine-resistant contraction of isolated chicken oesophagus in response to stimulation of parasymphathetic nerves.

1. Contractions of the chicken isolated oesophagus or separated external muscle produced by stimulation of the vagus and descending oesophageal nerves were abolished by hyoscine (1-100 mug/ml.) if the duration of stimulation was less than 5 sec, but prolonged stimulation produced delayed contractions not antagonized by hyoscine.2. The contractions to nerve stimulation were abolished by nerve section but not by bretylium, hexamethonium or tubocurarine.3. In decerebrate chickens, intravenous hyoscine abolished the contractions of the oesophagus produced by nerve stimulation, but previous intravenous injection of hyoscine into chicks did not prevent subsequently isolated oesophageal preparations from contracting to nerve stimulation.4. Prolonged nerve stimulation of an isolated oesophageal preparation did not produce a contraction from a piece of isolated guinea-pig ileum or post-crop chick oesophagus suspended in the same organ-bath.5. It seems possible that small amounts of a slow contracting substance were released from the stimulated nerves together with acetylcholine.

Animals↗