Search PubMed⌕ Search

Biomedical subjects

W H Hsu

Publications and source records attributed to W H Hsu.

At least 127 records · Page 7Linked to original sources
PubMed1989

Farrowing induction with cloprostenol-xylazine combination.

Eighty crossbred, multiparous sows, weighing between 190 and 320 kg, were randomly assigned to the following four treatment groups of 20 sows each: 1) saline-saline, 2) cloprostenol-saline, 3) saline-xylazine and 4) cloprostenol-xylazine. The mean gestation length of each multiparous sow was calculated. Cloprostenol (250 ug/sow, i.m.) or saline was given 3 d prior to the calculated due date at 11:30 a.m. Xylazine (2 mg/kg, i.m.) or saline was given 20 h after either the cloprostenol or previous saline treatment. Cloprostenol-xylazine treated sows had the shortest mean farrowing interval (1.5 +/- 0.3 h) when compared with the rest of the treatment groups (saline-saline:66.0 +/- 8.1, cloprostenol-saline:10.5 +/- 1.9, saline-xylazine:60.6 +/- 5.6 h). Farrowing time, percentage of stillbirths, average birth weight, d-5 and d-21 postbirth weights, number of pigs born, number of pigs born alive, and number of pigs surviving at 5 and 21 d afterbirth were not significantly different among the four groups. This study demonstrated that cloprostenol-xylazine treatment decreases the time to onset of farrowing with less variation than cloprostenol or xylazine alone. Therefore, the use of a cloprostenol-xylazine combination is suggested as an alternative method for inducing farrowing.

Journal Article↗
PubMed1989

The effects of jingsongling, a xylazine analog, on mean arterial blood pressure and heart rate in dogs--influences of yohimbine, tolazoline, prazosin, and atropine.

The effects of jingsongling (JSL) and xylazine on heart rate (HR) and mean arterial pressure (MAP) were studied in five conscious male dogs. An i.v. injection of xylazine (1 mg/kg) caused a bradycardia, an initial hypertension, and a subsequent hypotension. An i.v. injection of JSL (1 mg/kg) caused a bradycardia and a 20-min hypertension without a subsequent hypotension. Atropine sulfate (45 micrograms/kg, i.v.) increased HR for 30 min without changing MAP, and antagonized JSL-induced bradycardia for at least 60 min. There was a subsequent rebound bradycardia. Atropine sulfate potentiated JSL-induced hypertension in both magnitude and duration. Yohimbine (0.1 mg/kg, i.v.), an alpha 2-adrenoceptor antagonist, increased HR and MAP for 110 and 70 min, respectively. Yohimbine not only failed to potentiate but even reversed the pressor effect of JSL in a dose-dependent manner. Yohimbine also caused a dose-dependent reversal of JSL-induced bradycardia. Tolazoline (5 mg/kg, i.v.), a nonselective alpha-adrenoceptor antagonist, increased MAP for 20 min without changing HR. Tolazoline also reversed JSL-induced hypertension and bradycardia. Prazosin (1 mg/kg), an alpha 1-adrenoceptor antagonist, decreased MAP and increased HR for at least 110 min. Prazosin reversed JSL-induced hypertension but failed to affect JSL-induced bradycardia. These results indicated that: (1) JSL-induced bradycardia and hypertension are mediated by alpha 2-adrenoceptors; (2) yohimbine and tolazoline may be useful in antagonizing these untoward reactions associated with JSL administration, whereas prazosin and atropine were not found to be beneficial in this regard.

Animals↗
PubMed1989

Cloning and Expression of a Schwanniomyces occidentalis alpha-Amylase Gene in Saccharomyces cerevisiae.

An alpha-amylase gene (AMY) was cloned from Schwanniomyces occidentalis CCRC 21164 into Saccharomyces cerevisiae AH22 by inserting Sau3AI-generated DNA fragments into the BamHI site of YEp16. The 5-kilobase insert was shown to direct the synthesis of alpha-amylase. After subclones containing various lengths of restricted fragments were screened, a 3.4-kilobase fragment of the donor strain DNA was found to be sufficient for alpha-amylase synthesis. The concentration of alpha-amylase in culture broth produced by the S. cerevisiae transformants was about 1.5 times higher than that of the gene donor strain. The secreted alpha-amylase was shown to be indistinguishable from that of Schwanniomyces occidentalis on the basis of molecular weight and enzyme properties.

Journal Article↗
PubMed1989

Diagnostic value of adenosine deaminase and gamma-interferon in tuberculous and malignant pleural effusions.

It has been found that both adenosine deaminase (ADA) and gamma-interferon (r-IFN) are higher in tuberculous pleural effusions than in other types of pleural effusion. Both mechanisms may be related to the T-lymphocytes in effusions. We studied 39 pleural effusions: 19 tuberculous and 20 malignant [The ADA was determined according to the Giusti method and r-IFN by ELISA]. We compared the ADA and r-IFN levels in both groups of effusions and tried to determine if there was any correlation between them. The results showed: (1) The ADA enzyme level was significantly higher in tuberculous effusions than in malignant effusions as was expected (133.0 +/- 50.4 vs 32.0 +/- 17.7 U/L). (2) The r-IFN was also significantly higher in tuberculous effusions than in malignant effusions (30.4 +/- 17.4 vs 2.9 +/- 2.8 U/ml). (3) The coefficients of regression for the ADA and r-IFN levels were poor. In conclusion, both tests for measuring ADA and r-IFN levels are excellent methods for differentiating tuberculous and malignant effusions, and especially measurement of the r-IFN level could serve as a more specific test for differentiating malignant pleural effusions with high ADA levels. However, no strong correlation was found between the ADA and r-IFN levels.

Adenosine Deaminase↗
PubMed1989

Effects of idazoxan, tolazoline, and yohimbine on xylazine-induced respiratory changes and central nervous system depression in ewes.

We compared the ability of 3 alpha 2-adrenoreceptor antagonists, idazoxan (0.05 mg/kg), tolazoline (2 mg/kg), and yohimbine (0.2 mg/kg) to reverse xylazine (0.3 mg/kg)-induced respiratory changes and CNS depression in 6 ewes. Once weekly, each ewe was given a random IV treatment of xylazine, followed in 5 minutes by either an antagonist or 0.9% NaCl solution. Xylazine alone caused recumbency for 54.2 +/- 5.3 minutes (mean +/- SEM). Xylazine also increased respiratory rate and decreased PaCO2 for at least 45 minutes, but did not significantly change arterial pH or PaCO2. Idazoxan and tolazoline were equally effective in reversing the respiratory actions of xylazine; however, yohimbine was less effective in reducing the respiratory rate and was ineffective in antagonizing the decreased PaO2. Idazoxan and tolazoline decreased the duration of xylazine-induced recumbency to 6.3 +/- 0.6 and 9.5 +/- 2.3 minutes, respectively, whereas yohimbine did not significantly change this effect of xylazine. Thus, at the dosages studied, idazoxan and tolazoline appeared to be more effective than yohimbine in reversing the respiratory and CNS depressant actions of xylazine in sheep.

Adrenergic alpha-Antagonists↗
PubMed1989

[Effects of xylazole on heart rate and blood pressure in conscious dogs].

Xylazole (Xyl) is an analogue of xylazine (Xyn) synthesized by Lanzhou Institute of Chinese Traditional Veterinary Medicine. The effects of Xyl on heart rate and blood pressure were studied in 5 conscious dogs. Xyl 1 mg/kg iv was similar to Xyn in producing bradycardia and an initial transient hypertension followed by a lasting hypotension which was less significant than Xyn. Yohimbine (0.1 and 0.3 mg/kg), an alpha 2-adrenoreceptor blocking agent, antagonized bradycardia and hypotension induced by Xyl. Tolazoline (3.3 mg/kg), a nonselective alpha-adrenoreceptor blocking agent, reversed the bradycardia and hypotensive effect. Prazosin (1 mg/kg), an alpha 1-adrenoreceptor blocking agent, did not change Xyl-induced bradycardia and hypotension. Atropine (20 micrograms/kg) not only antagonized Xyl-induced bradycardia but also changed from bradycardia to tachycardia, and greatly potentiated Xyl-induced hypertension for more than 30 min. The results suggested that Xyl-induced cardiovascular effects are similar to Xyn that mediated by alpha 2-adrenoreceptor.

Adrenergic alpha-Agonists↗
PubMed1989

Production of isoamylase by Pseudomonas amyloderamosa mutant strain JD210.

Nutritional requirements for the production of isoamylase by Pseudomonas amyloderamosa mutant strain JD210 were investigated. The optimal initial pH for enzyme production in shake-flask cultivation was 5.0. Maltose and soybean protein hydrolyzate were found to be the best carbon source and nitrogen source, respectively. The enzyme production was drastically inhibited by Zn+2 and Cu+2. Other metal ions phosphates and surfactants exhibited no significant inhibitory or accelerating effect on enzyme production. According to auxanography and single omission experiments, proline and isoleucine were required for growth. The supplement of 0.1% proline increased enzyme production by around 30% compared with no addition.

Amino Acids↗
PubMed1989

Antagonistic effect of idazoxan on xylazine-induced central nervous system depression and bradycardia in calves.

Two doses of an alpha 2-adrenoreceptor antagonist, idazoxan, were administered to reverse the CNS depressant and bradycardia effects of xylazine in calves. Once a week for 3 weeks, each of 6 calves were administered IV one treatment of: (1) 0.2 mg of xylazine/kg of body weight followed in 10 minutes by 1 ml of 0.9% NaCl, (2) 0.2 mg of xylazine/kg followed in 10 minutes by 10 micrograms of idazoxan/kg, or (3) 0.2 mg of xylazine/kg followed in 10 minutes by 30 micrograms of idazoxan/kg. The order of the 3 treatments in each calf was selected at random. Xylazine alone caused lateral recumbency for 27.2 +/- 3.0 minutes (mean +/- SEM). Idazoxan administered at dosages of 10 and 30 micrograms/kg shortened xylazine-induced lateral recumbency to 11.5 +/- 0.8 and 10.3 +/- 0.2 minutes, respectively. Calves given xylazine alone stood at greater than 60 minutes after the onset of recumbency. Idazoxan given at dosages of 10 and 30 micrograms/kg shortened the time to standing to 16.8 +/- 1.7 and 11.3 +/- 0.2 minutes, respectively. Idazoxan given at a dosage of 30 micrograms/kg also reversed xylazine-induced bradycardia. Results indicated that idazoxan should be a useful antidote for xylazine overdose in cattle.

Animals↗
PubMed1989

Primary mediastinal seminoma.

Primary mediastinal seminoma is a rare neoplastic disease. Only 133 cases have been reported in the literature. Five patients with primary mediastinal seminoma had been treated at VGH from 1974 to 1986. All of them received exploratory thoracotomy but only two of them were resectable. Postoperative radiation therapy was given regardless of resection. One had additional chemotherapy due to nodal involvement. All five patients showed complete resolution and were alive and free of disease for an average follow-up period of 42.6 months (range, 5-82 months). So we conclude that mediastinal seminoma is a rare neoplastic disease and can be treated primarily by surgery. Irradiation can also induce complete remission and long term survival in those with unresectable tumors.

Adult↗
PubMed1988

The bradycardic and mydriatic effects of chlordimeform and its demethylated analogs in the rat: antagonism by idazoxan but not by prazosin.

Pupillary and cardiac responses to i.v. injections of chlordimeform (CDM, 0.3-10 mg/kg), a formamidine insecticide, and its metabolites demethylchlordimeform (DCDM, 0.03-1 mg/kg) and didemethylchlordimeform (DDCDM, 0.1-3 mg/kg) were studied in rats anesthetized with pentobarbital. Both CDM and DCDM induced a dose-dependent mydriasis and bradycardia and DCDM was 10 times more potent than CDM in causing these effects. In contrast, DDCDM did not induce a mydriasis or bradycardia. The alpha 2-adrenoreceptor antagonist, idazoxan (0.2 mg/kg, i.v.) abolished or reduced CDM- and DCDM-induced mydriasis and bradycardia, whereas the alpha 1-adrenoreceptor antagonist, prazosin (1.5 mg/kg, i.v.) did not change these effects of CDM and DCDM. SKF 525-A (50 mg/kg, i.p.), an inhibitor of enzymatic demethylation, administered 10 min before the first dose of CDM, failed to reduce the effects of CDM. The results suggested: 1) the mydriatic and bradycardic effects of CDM and DCDM are mediated by alpha 2-adrenoreceptors, 2) the monodemethylation of CDM increases its alpha 2-adrenoreceptor agonistic activities, but the didemethylation of CDM abolishes these activities, and 3) CDM can exert alpha 2-adrenoreceptor agonistic activities without undergoing a demethylation process.

Amidines↗
PubMed1988

Yohimbine increases plasma insulin concentrations and reverses xylazine-induced hypoinsulinemia in dogs.

Xylazine (1.1 mg/kg of body weight, IV), an alpha 2-adrenoreceptor agonist, suppressed the increase in plasma insulin concentration induced by glucose (0.6 g/kg, IV) in dogs. Yohimbine (0.11 mg/kg, IV), an alpha 2-adrenoreceptor antagonist, given 5 minutes after xylazine, reversed effects of xylazine, whereas yohimbine alone increased plasma insulin and decreased plasma glucose concentrations. Seemingly, alpha 2-adrenoreceptors exert a negative control of insulin release.

Animals↗
PubMed1988

Effects of topical application of amitraz on plasma glucose and insulin concentrations in dogs.

Amitraz, a formamidine insecticide, is used topically in the treatment of demodicosis and other ectoparasitic infestations. When 3.78 L (containing 2.1 g) of amitraz (twice the recommended concentration) was applied to 5 dogs 4 hours before glucose (0.6 g/kg of body weight) was administered IV, plasma glucose concentration increased, but the increase in plasma insulin concentration, which usually follows IV administered glucose, was suppressed. The results suggested that amitraz induced hyperglycemia at least partly by inhibiting insulin release.

Administration, Topical↗
PubMed1988

The outcome of thymectomy in nonthymomatous myasthenia gravis.

From October 1979 to December 1984, 77 patients with nonthymomatous myasthenia gravis underwent thymectomy and 74 patients were available for careful follow-up study in this review. Among these 74 patients, 18 were male and 56, female. Their ages ranged from 13 to 68 years with an average age of 30.2 years. Men tend to be affected at a later age than women (an average age of 38.0 versus 26.1 years). Duration of the disease was from one to 30 years, with an average of 4.2 years. A sternal-splitting incision was performed for all patients. Thymectomy was made by removal of all anterior mediastinal fat between the pleuropericardial reflection and phrenic nerve bilaterally. Seventy of the 74 patients benefited from thymectomy. Of these, 34 patients had remission and 36 patients had substantial improvement; three patients did not improve after thymectomy but did not increase in severity of symptoms or medication requirement. There was no postoperative death. Myasthenic crisis developed in four patients and five patients had pulmonary complications. These nine patients were among the 21 patients who did not receive either plasmapheresis preoperatively or a high dose of steroids perioperatively. Early thymectomy is recommended for patients with nonthymomatous myasthenia gravis. We also recommend that patients undergoing thymectomy should be treated either with plasmapheresis preoperatively or with high doses of steroid perioperatively.

Adult↗
PubMed1987

Effects of tolazoline and yohimbine on xylazine-induced central nervous system depression, bradycardia, and tachypnea in sheep.

We compared the ability of tolazoline and yohimbine to antagonize xylazine-induced central nervous system depression, bradycardia, and tachypnea in 9 ewes and 5 rams. Once a week for 3 weeks, each sheep received one IV treatment of 0.4 mg xylazine/kg, 0.4 mg xylazine/kg followed in 10 minutes by 2 mg tolazoline/kg, or 0.4 mg xylazine/kg followed in 10 minutes by 0.2 mg yohimbine/kg. The order of the 3 treatments in each sheep was randomized. Xylazine alone caused recumbency for 41.0 +/- 3.7 minutes (mean +/- SEM). Tolazoline and yohimbine shortened the xylazine-induced recumbency to 12.1 +/- 0.9 minutes and 18.1 +/- 1.5 minutes, respectively. Sheep given xylazine alone had head droop for 34.0 +/- 5.4 minutes after rising. Head drooping of sheep given tolazoline or yohimbine was reduced to 10.1 +/- 1.7 minutes and 14.2 +/- 1.7 minutes, respectively. Both tolazoline and yohimbine reversed the bradycardia and tachypnea that followed xylazine administration. No statistical differences in the rate and magnitude of the reversal were observed between the 2 drugs.

Animals↗
PubMed1987

Yohimbine increases plasma insulin concentrations of dogs.

Recent evidence suggests that catecholamines inhibit insulin release by stimulating alpha 2-adrenoreceptors in beta-cells of the pancreatic islets. In the present study, iv injections of 0.1 and 0.3 mg/kg of yohimbine, an alpha 2-adrenoreceptor antagonist, resulted in increased plasma insulin and decreased plasma glucose concentrations in the dog. The use of alpha 2-adrenoreceptor antagonists may be of value in non-insulin-dependent diabetic patients by counteracting the inhibitory influence of endogenous catecholamines.

Animals↗
PubMed1987

Monoclonal antibodies against human esophageal carcinoma cell lines.

Two monoclonal antibodies, designated 4C4 and 4G1, were produced by immunization of BALB/c mice with a human esophageal carcinoma cell line, CE69T/VGH, followed by fusion of the spleen cells from an immunized mouse with myeloma cells NS-1. 4C4 showed strong binding activity to three human esophageal carcinoma cell lines and one human hepatoma cell line, but not to any other cell lines tested. 4G1 reacted with three human esophageal carcinoma cell lines and four other cell lines. By peroxidase-antiperoxidase staining, 4C4 and 4G1 detected antigens of the epithelial cells on 10 pairs of esophageal carcinoma and normal esophageal specimens. 4G1 recognized a CE69T/VGH antigen with a molecular weight of 180K. Since 4G1 also reacted with purified carcinoembryonic antigen (CEA) and immunoprecipitated 125I-CEA, 4G1 seems to be an antibody recognizing CEA produced by CE69T/VGH cells. Since 4C4 also bound to the epithelial cells of normal uterine, vaginal, breast and liver tissues, it seems to recognize an epithelial antigen, and can be used to characterize the antigen in the specialization or differentiation of epithelial cells.

Animals↗