Biomedical subjects

Y C Hung

Publications and source records attributed to Y C Hung.

47 records · Page 3Linked to original sources

PubMed1996

Identification of ent-16 beta, 17-dihydroxykauran-19-oic acid as an anti-HIV principle and isolation of the new diterpenoids annosquamosins A and B from Annona squamosa.

Phytochemical analysis of the fruits of Annona squamosa yielded 12 known kaurane derivatives (1-11, 13) and two new kaurane diterpenoids, which have been named annosquamosin A (16 beta-hydroxy-17-acetoxy-ent-kauran-19-al) (12) and annosquamosin B (19-nor-ent-kaurane-4 alpha,16 beta,-17-triol) (14). The structures of the new compounds were established by spectral analyses and chemical evidence. Among these 14 compounds, 16 beta, 17-dihydroxy-ent-kauran-19-oic acid (2) showed significant activity against HIV replication in H9 lymphocyte cells with an EC50 value of 0.8 microgram/mL (therapeutic index > 5).

Antiviral Agents↗

PubMed1996

Dark-cycle video surveillance of sexual performances of normal and diabetic rats.

Clinically, a 59% prevalence of impotence was reported among diabetic male patients. Neurological, vascular, endocrinologic and psychological factors are probably involved. Previous reports with the rat model found deterioration of sexual behavior and reproductive function caused by streptozotocin (STZ)-induced diabetes. The purpose of the present study was to develop the dark-cycle video recording methodology for the observation of rat sexual activities and to study the effect of STZ-induced diabetes on sexual performances of the rat. Adult male Wistar rats were rendered diabetic with intraperitoneal injection of STZ (60 mg/kg body weight). In the 4th week a diabetic rat or a control rat was caged with an adult ovariectomized female rat during the dark cycle. The female had been brought into behavioral estrus with intramuscular injection of 0.1 mg estradiol benzoate 3 days before and 1.0 mg progesterone 3 h before testing. Infrared-light-illuminated video recording was performed to evaluate the sexual performances. The mounting latency and frequency, intromission latency and frequency, the hit rate as well as the post-ejaculatory period of the diabetic rats were significantly deteriorated when compared with the controls (p < 0.05). However, the ejaculatory latency showed no significant difference between the two groups (p > 0.05). In conclusion, it has been demonstrated that with this methodology, behavioral studies on nocturnal animals like the rat can be carried out conveniently. It was shown that the sexual arousal mechanism and copulation-ejaculatory mechanism were both depressed in STZ-induced diabetic rats. The same study model can be used for further pathophysiological and pharmacological researches on the sexual behaviors of diabetic rats.

Animals↗

PubMed1996

Treatment effect of "ryu-wei-ti-huang-wan" (a Chinese herbal prescription) on the sexual performance of male rats with streptozotocin-induced diabetes.

The treatment effect of "ryu-wei-ti-huang-wan', a Chinese prescription composed of extracts from six plants, on diabetic impotence was evaluated in the present study. Adult male Wistar rats were divided into three groups: (1) rats rendered diabetic with a single intraperitoneal injection of streptozotocin (60 mg/kg body weight); (2) rats with streptozotocin-induced diabetes treated with a ryu-wei-ti-huang-wan powder preparation at a dose of 30 mg powder/kg body weight twice a day, and (3) control rats. A male rat was caged with an adult ovariectomized female rat during the dark cycle. Infra-red-light-illuminated video recording was utilized to evaluate the sexual performance. The diabetic rats exhibited depressed mounting activity and no intromission or ejaculation. After ryu-wei-ti-huang-wan treatment either for 1 day or 2 weeks, the diabetic rats showed significant improvement in mounting performance with preservation of intromission and ejaculation. No significant difference in the blood sugar level was noted between the treatment and non-treatment groups. In conclusion, the diabetic rats showed impairment in sexual arousal, erectile as well as ejaculatory functions. Ryu-wei-ti-huang-wan was effective in preserving these functions with a rapid onset. It is evident that the extracts exert the therapeutic effects not through a lowering of blood sugar. These substances are potentially useful in the clinical treatment of male diabetic impotence.

Animals↗

PubMed1996

Evidence of nonadrenergic, noncholinergic contraction in rat urinary bladder by 1,1-dimethylphenylpiperazinium stimulation in vivo.

Nonadrenergic, noncholinergic (NANC) contraction has been demonstrated in animal urinary bladder. However, the exact nature of the NANC innervation is still unclear. 1,1-Dimethylphenylpiperazinium (DMPP), which generates action potentials in the cell body of the postganglionic neuron and causes neurotransmitter release (both acetylcholine and noradrenaline), was given intravenously (0.1-0.7 mg/kg) to 3-month-old female Wistar rats under anesthesia (n = 20). Intravesical pressure, heart rate and blood pressure of the rats were monitored on Gould polygraph. Monophasic dose-dependent contractile response was observed upon administration of DMPP in 12 of 20 rats. After total adrenergic and cholinergic blockade with atropine, guanethidine, phentolamine and propranolol, the contractile response was reduced, not completely, in the animals. At the dose of 0.7 mg/kg, the contraction was reduced to about 48% of the original response. The study provides in vivo evidence for NANC contraction in the rat urinary bladder, moreover, the neurotransmitter is released from the postganglionic neurons.

Action Potentials↗

PubMed1996

Some chemical and physical properties of bambara groundnut (Voandzeia subterranea Thouars) seed and products.

Some chemical and physical properties of bambara groundnut seed were determined. The proximate composition of the bambara groundnut seed was found to be 9.7% moisture, 16.6% protein, 5.9% fat, 2.9% ash, 4.9% crude fibre and 64.9% carbohydrate. Maximum water absorption was attained after soaking for 11, 9, 6, and 4 h at 25, 40, 50, and 60 degrees C, respectively. Maximum dehulling efficiency was attained when the seeds absorbed 54.7% water and drying for 9 h at 60 degrees C. Study of the microstructure of the raw flour and seed showed that they contained differently shaped and sized starch granules and protein materials within the cell wall in the cotyledon. Milling disorganised the arrangement of these components in the cotyledons. In the steamed moin-moin ('okpa'), all components in the seed had lost their identity and integrity.

Dietary Carbohydrates↗

PubMed1996

Validity of force platform measures for stance stability under varying sensory conditions.

Maintaining stance stability under varying sensory environment is an essential function in the elderly and among patients. Testing sensory organization ability of standing balance, the Sensory Organization Test (SOT), has become a standard procedure in many clinical and laboratory settings. The stance stability can be quantified by two forceplate measures in the SOT: the equilibrium score (ES) and the sway area (SA). This study compares the validity of the ES and the SA in detecting gender, trial, and sensory effects on stability in twenty (ten male, ten female) healthy young adults. Subjects were tested under six sensory conditions: eyes open (EO), eyes closed (EC), sway-referenced vision (Vs), sway-referenced support surface (Ss), eyes closed sway-referenced support surface (ECSs), and sway-referenced visual surround and support surface (VsSs). A visual surround and/or the support surface were tilted proportionately to the subject's spontaneous sway in the sway-referenced conditions. Three trials, 20-second for each trial, were repeated for each sensory condition. Above results demonstrated that the Pearson correlation coefficients between the ES and the SA were all highly significant (p < .0001) except for the first trial of the EO condition. The consistencies in which the two measures discriminated among sensory conditions were tested by the Kendall's coefficient of concordance. The Kendall's coefficient for the ES (W = .843) and the SA (W = .866) were high and similar. Separate ANOVA procedure for the ES and SA revealed that both measures satisfactorily detected a significant sensory condition and trial effects and insignificant gender effect. We can conclude that ES and SA are valid measures of stance stability during the SOT. Our results confirm that healthy young adults have a poorer postural stability when the visual and somatosensory inputs are simultaneously altered. Moreover, the learning effect is observed during repeated trials within test conditions.

Adult↗

PubMed1995

Effects of pregnancy and progesterone on autonomic function in the rat urinary bladder.

Previous studies have shown that pregnancy is associated with a decrease in cholinergic function in the rabbit urinary bladder. The present study aimed at evaluating the effects of pregnancy on the autonomic function of the rat urinary bladder and to elucidate whether progesterone is responsible for such alterations. Female Wistar rats, 3 months old, were divided into four groups: (1) 2-week pregnant rats; (2) rats given daily intramuscular injections of progesterone 5 mg/kg for 2 weeks; (3) rats given intramuscular injections of vehicle for 2 weeks, and (4) controls. Cystometry showed a significant increase in bladder capacity in the pregnant rats. The wet weight of the pregnant rat bladder was also significantly increased. Histologic study revealed increased bladder wall thickness with interstitial edema and urothelium proliferative changes to a papillary configuration in these pregnant bladders. Bladder muscle strip study showed significantly reduced maximum contractile responses to acetylcholine and methoxamine in the pregnant and the progesterone groups. Muscarinic receptor binding study demonstrated reduced Bmax in the pregnant rats and rats receiving progesterone injections (control group Bmax = 57 +/- 11, pregnant group Bmax = 44 +/- 8, p < 0.05; progesterone group Bmax = 40 +/- 7, vehicle group Bmax = 58 +/- 9 fmol/mg protein, p < 0.05). The contractile response to lower concentrations (10(-6) mol/l to 10(-4) mol/l) of ATP was elevated in the pregnant rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Effect of alpha-chymotrypsin on the nonadrenergic, noncholinergic contraction of the rat urinary bladder in vitro.

The role of peptides in mediating the nonadrenergic, noncholinergic (NANC) response of the rat urinary bladder was studied. Electrical stimulation of muscle strips from 3-month-old female Wistar rat urinary bladders in the presence of autonomic blockers (atropine 10(-6) mol/l, propanolol 10(-6) mol/l, phentolamine 10(-6) mol/l, and guanethidine 10(-6) mol/l) showed NANC contraction accounting for 60% of the maximum contractile responses at 40 Hz. Frequency-response studies showed that in the presence of alpha-chymotrypsin (2 U/ml, 30-min incubation), the NANC contractile responses to electrical stimulation at lower frequencies (3-10 Hz) were enhanced (p < 0.05; n = 9). However, no significant differences were observed at higher frequencies (20-40 Hz). With repetitive 4-Hz stimulation, alpha chymotrypsin caused a 19% increase in the NANC contractile response (p < 0.05; n = 8). It is postulated that the NANC response of the rat bladder smooth muscle is composed of an excitatory (contractile) and an inhibitory (relaxant) component. Some peptide(s) is/are responsible for mediating the inhibitory response.

Acetylcholine↗

PubMed1995

Effect of protein and starch degradation rates on rumen metabolism in Taiwan native goat.

Six ruminal and duodenal cannulated Taiwan native goats (body weight = 20 kg) were fed 35% roughage, 65% concentrate diet (crude protein = 9.5%) in a 6 x 6 Latin square design to study the effect of the combination of 3 varying starch (corn) and 2 varying protein (soybeans) ruminal degradation rates on ruminal microbial density and ruminal nutrient digestibilities. Goats in treatment consisting of both rapid starch and protein ruminal degradation rates had higher total bacterial and protozoal numbers than did those in other treatments (p < 0.05). The combination of rapid starch degradation rate and slow protein degradation rate supported the highest numbers of Holotrichs whereas the combination of both rapid starch and protein degradation rate supported the highest numbers of Entodiniomorphs. Ruminal starch digestibilities were higher for treatment diets with autoclaved corn than for those with raw corn whereas ruminal digestibility of protein was greater in diets with raw soybeans than in those with heated ones. Higher neutral detergent fiber digestibilities in the rumen were found with the raw corn rations and the raw soybean rations.

Animals↗

PubMed1991

[Combined CA-125 test and ultrasonography in the presurgical evaluation of ovarian mass].

Clinicians are urgently searching for ways of differentiating a malignant from a benign ovarian mass. How to approach or what is the prognosis? Some have shown the CA-125 test combined with ultrasonography to be highly sensitive and specific, when compared to single parameter. We examined 238 patients who underwent laparotomy for adnexal mass. Of these 44 were found to suffer from malignant tumors and 194 from benign lesions. Before the operation, CA-125 level was measured; pelvic ultrasonography was performed on each patient and the sonographic data were evaluated on an echostructural scoring system. After a sophisticated computer assisted analysis, the results of the combined tests were CA-125 greater than or equal to 65 U/ml or US score greater than or equal to 8 with a sensitivity of 77.3%, a specificity of 81.4% and a diagnostic accuracy of 80.7%. Therefore we confirm that CA-125 may be considered as a useful adjunct to sonography in the differential diagnosis of adnexal mass.

Antigens, Tumor-Associated, Carbohydrate↗

PubMedDate not supplied

Evaluation of substrates and storage conditions for preparing and maintaining starter cultures for tempeh fermentation.

Heat-pasteurized cassava root, cowpeas, partially defatted peanuts, rice and soybeans were evaluated for their suitability to support growth and sporulation of the tempeh mold, Rhizopus microsporus var. oligosporus, and the oncom mold, Neurospora intermedia, at 25, 30 and 37 degrees C. The molds grew best and sporulated most luxuriantly on cassava and rice incubated at 37 degrees C. Viability of molds remained high for up to 30 weeks when dried (a(w) 0.48), powdered substrates on which the molds had been cultured, were stored at 5, 25 and 37 degrees C. Survival was best when powders were stored at 5 degrees C, although storage at 25 degrees C did not cause a marked decline in CFU/g. R. microsporus var. oligosporus starter cultures produced on rice and then stored for 20 weeks at these temperatures compared most favorably with commercial starter cultures for preparing high-quality soybean tempeh. The simple technology required to prepare these starter cultures enhances the potential for their application in developing countries where the introduction of nontraditional fermented legume foods to low-protein diets could help to ameliorate malnutrition.

Arachis↗