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Biomedical subjects

Y Huang

Publications and source records attributed to Y Huang.

At least 757 records · Page 42Linked to original sources
PubMed1997

Differential effects of pinacidil, cromakalim, and NS 1619 on electrically evoked contractions in rat vas deferens.

AIM: To compare the inhibitory action of electrically evoked contractions of rat epididymal vas deferens by pinacidil (Pin), cromakalim (Cro), and NS 1619. METHODS: Monophasic contractions were evoked by electric field stimulation in rat isolated epididymal half of vas deferens. RESULTS: Newly developed ATP-sensitive K+ channel openers, Pin and Cro, concentration-dependently reduced the electrically evoked (0.3 Hz, 1 ms pulse duration, 60 V) contractions and glibenclamide but not charybdotoxin antagonized the inhibitory effects of both agents. Pin shifted the concentration-response curve for norepinephrine to the right with reducing the magnitude of the maximum contraction in a glibenclamide-sensitive fashion. The large-conductance Ca(2+)-activated K+ channel opener, NS 1619, inhibited the electrically evoked contractions in a concentration-dependent manner. Charybdotoxin (100 nmol.L-1) partially reduced the effect of NS 1619 but glibenclamide (10 mumol.L-1) showed no effect. None of these 3 agents affected the basal tension. CONCLUSION: Both ATP-sensitive and Ca(2+)-activated K+ channels presented in vas deferens smooth muscles involved in regulation of muscle contractility.

Animals↗
PubMed1997

Effects of MCI-154 on calcium sensitivity of contractile system and calcium release from sarcoplasmic reticulum in saponin-skinned rat myocardium.

AIM: To explore the possible mechanisms underlying the positive inotropic effect of MCI-154. METHODS: Skinned fibers with disrupted or preserved sarcoplasmic reticulum (SR) were prepared by saponin 500 or 50 mg.L-1. The tension-pCa relationship and pCa50 of saponin (500 mg.L-1)-skinned fibers were taken as the indices of Ca2+ sensitivity of contractile proteins. The amplitude of caffeine-induced contracture was an index of Ca2+ release from SR in saponin (50 mg.L-1)-skinned fibers. RESULTS: 1) MCI-154 (0.1 mmol.L-1) showed a Ca2+ sensitizing effect on contractile proteins. The pCa50 was increased to 5.84 (5.54-6.14) compared with control value 5.54 (5.30-5.79) (P < 0.01, n = 8). Hill coefficient n was decreased by 0.29 (P < 0.01, n = 8); 2) No contracture was produced by MCI-154 in preparations with preserved SR. Caffeine-induced contracture before and after MCI-154 treatment were not changed (P > 0.05, n = 4). CONCLUSION: MCI-154 directly enhances the Ca2+ sensitivity of contractile protein but has little effect on Ca2+ release from SR in rat skinned cardiac fibers.

Animals↗
PubMed1997

[Report of four cases of 22 channel cochlear implantations].

22 channel cochlear implants were implanted in 3 postlinguistical deafened adults and a prelinguistical deafened adolescent. All 4 patients including one with total cochlear ossification and another with congenital cochlear malformation showed significant auditory performance and demonstrated satisfactorily improved speech perception test scores postoperatively.

Adolescent↗
PubMed1997

[Study on substance P immunoreactivity after acute crush injury to facial nerve].

This paper presents the change in substance P immunoreactivity (SP-IR) after acute crush injury to the vertical part of facial nerve of normal cats by using immunohistochemical and immunocytochemical techniques combined with immunoelectronic microscopy. The electroneuromyogram (ENOG) shows that the cats have suffered from fully peripheral facial paralysis. It is found that the SP-IR positive products and fibers increase in the other part of facial nerve (including the non-injured part of vertical segment and level segment) after injury, especially six days later. As a result, it is suggested that the regeneration and repair of facial nerve might be in close relationship with substance P after acute crush injury to it.

Animals↗
PubMed1997

[Carotid cavernous fistula (report of 14 cases)].

Fourteen cases of carotid cavernous fistula (CCF), including 9 cases of traumatic CCF and 5 cases of spontaneous CCF, were treated respectively or in combination with the ligation of the carotid, the isolation of the fistula, following clipping of its upper and lower reaches of the carotid, and endovascular treatment of balloons, steel coils, dry frozen dural pieces or Ivalon grains. It is considered that the detachable balloon endovascular embolization is a choice treatment for CCF.

Adult↗
PubMed1997

[Local electroretinogram and pattern visual evoked potential in maculopathies].

OBJECTIVES: To observe the changes of local electroretinogram (LERG) and pattern visual evoked potential (PVEP) in maculopathies and to evaluate the value of both LERG and PVEP in clinical application. METHODS: LERGs at 5 degrees, 10 degrees and 15 degrees macular region were recorded from 27 normal subjects (54 eyes). The LERG and PVEP were recorded from 25 patients (35 eyes) with maculopathies. RESULTS: In the patients with maculopathies, the amplitudes of LERG a wave and b wave at 5 degrees, 10 degrees and 15 degrees macular region were significantly lowered (P < 0.01), the mean value of P1 latency was prolonged and that of N1-P1 amplitude of VEP was lowered at 36.5', 73' and 146' in the comparison with the control group. In approximately the same stimulated area (15 degrees LERG and 14.8 degrees x 19.0 degrees PVEP), the abnormal rate of LERG was 62.2%, and the abnormal rates of PVEPs were 48.5% (146'), 54.5% (73') and 48.5% (36.5') respectively, no significant difference in the abnormal rate between LERG and each value of PVEP (P > 0.05) being found. CONCLUSION: The abnormal rates of LERG and PVEP in maculopathies are close. Because LERG is not influenced by visual pathway diseases and visual acuity, LERG is more effective than PVEP and is a direct way in measuring macular function.

Adult↗
PubMed1997

[Quantitative electroencephalogram monitoring the depth of anesthesia during skin incision].

We investigated the EEG parameter changes of skin incision during different depth of sevoflurane/nitrous oxide analgesia. 65 ASA physical status I patients (aged 34 +/- 12 yr) scheduled for elective abdominal surgery were studied. The tracheal of each patient was intubated and the lungs were ventilated. Patients were randomly assigned to one of three groups. Anesthesia was maintained with 1% (group I n = 25), 1.5% (group II n = 20) or 2% (group III n = 20) end-tidal sevoflurane concentration in 66% nitrous oxide. Each of the concentration levels was maintained for at least 15 minutes before surgical incision. The EEG electrodes were placed on each patient in a front-oparietal montage (Fp1- A1, Fp2- A2) referred to Cz. EEG was recorded during 3-min period before incision. Hemodynamic variables were also monitored. Inadequate anesthetic depth was defined as patient movement in response to a 5-cm skin incision. The ventilation was controlled to maintain normocapnia (PETCO2 5 +/- 0.04 kPa). The data were analysed using ANOVA, liner correlation analysis and t-test. A significant difference between EEG parameters (SEF, BIS,) and skin incision responsive rate were found among the three concentration groups (P < 0.01). There were no difference of hemodynamics among the three groups. Patients who moved at incision also had significantly higher SEF, BIS leveles compared to non-movers (P < 0.01). Quantitative EEG determinants were correlated well with the end-tidal sevoflurane concentration and were a useful predictor of patient movement in response to skin incision during sevoflurane/nitrous oxide anesthesia.

Adolescent↗
PubMed1997

[Diagnosis and treatment of congenital choledochal cysts in adults].

We report the experience with 97 adult patients with bile duct cysts in the past 30 years (1965-1995). The median age at time of initial therapy in our department was 37 years (range, 16 to 78 years). Clinical symptoms in most cases were non-specific, resulting in delayed diagnosis. 74 patients (76%) had coexistent pancreaticohepatobiliary disease. Carcinoma of the biliary duct occurred in 16 patients (17%). Abnormal pancreatobiliary duct junction (APBDJ) was found in 28 patients. 94 patients underwent a total of 169 biliarytract procedures. Cyst excision with Roux-en-y hepaticojejunostomy and internal drainage were the main procedures. The result of long-term follow-up shows that internal drainage frequently resulted in recurrent cholangitis and cyst malignancy which need reoperation. In contrast, cyst excision was associated with a significantly lower incidence of recurred cholangitis and lower occurrence of malignancy. Thus, cyst excision with Roux-en-y hepaticojejunostomy is recommended as the treatment of choice for adult patient.

Adolescent↗
PubMed1997

[Experimental study on the effect of extremities ischemia reperfusion inducing anterior tibial compartment pressure].

We observed the changes of compartment pressure after extremities were reperfused at different intervals of ischemia and its relationship with the changes of serum MDA and CPK content. The protective effect of mannite on extremities ischemia reperfusion was also studied. 18 New Zealand rabbits were separated into three groups: group A (ischemia 4 h); group B (ischemia 8 h); group C (ischemia 4 h). The rabbits of group A and B were intravenous injected with normal saline (NS), and group C was injected with 20% mannite. The changes of compartment pressure of serum MDA and CPK content and the histological changes of skeletal muscles in every group were noted at different times: preoperation; the beginning of ischemia; the end of ischemia and reperfusion for 4 h; 24 h; 72 h, respectively. The longer ischmia lasted, the more serious the tissue damage was. Reperfusion made tissue damaged further. After reperfusion for 24 h, the damage was the most serious. Meanwhile, the serum MDA and CPK content also reached the peak value. These changes were in accord with those of compartment pressure. On the other hand, the damage of mannite group was relatively mild. Extremity ischemia reperfusion would led to the increase of compartment pressure, then intensified the damage. The damage was the most serious at 24 h of reperfusion. Using mannite could reduce the tissue damage and compartment pressure. Mannite should be recommended as the first-selected drug for extremity ischemia reperfusion injury.

Animals↗
PubMed1997

[Histopathologic and immunochemical changes in Sjögren's syndrome].

To research into the causes of sjögren's syndrome, we investigated the lacrimal gland tissues of 6 cases of sjogren's syndriome by using electronmicroscopy and immunochemical methods. The results revealed that at the early stage the lacrimal gland cells showed degeneration, irregular arrangement and many intracellular vacuoles. At the middle stage, some lymphocytes infliltrated into the gland tissues. And at the advanced stage, lymphocytes and collagenous fibers were there in substitution of gland cells.

Adult↗
PubMed1997

[Significance of c-erbB-2 and PCNA expression in adenocarcinoma of uterine cervix].

OBJECTIVE: Significance of c-erbB-2 and PCNA expression in adenocarcinoma. METHODS: Expression of c-erbB-2 and PCNA in 74 cases of adenocarcinoma of the uterine cervix was examined by immunohistochemistry. RESULTS: The expression of c-erbB-2 was detected in 34 cases. The positive staining of c-erbB-2 was associated with increased lymph node metastasis (57.1% Vs 24.0%, P = 0.041) and lower 5-year survival rate (32.4% Vs 58.9%, P = 0.008). The average PCNA labelling index (PCNALI) was 40.6% (0.1%-91.4%). High PCNALI was associated with lymph node metastasis (56.4% Vs 38.5%, P = 0.016) and lower 5-year survival rate (28.7% Vs 64.4%, P = 0.005). Positive staining of c-erbB-2 were associated with high PCNALI (44.7% Vs 34.6%, P = 0.003). CONCLUSION: c-erbB-2 and PCNALI were associated with malignant biological behavior and poor prognosis. They may be potential prognostic factors in cervical adenocarcinoma.

Adenocarcinoma↗
PubMed1997

[Mechanism of protective action of Phyllanthus urinaria L. against injuries of liver cells].

It has been found out that the carbon tetrachloride (CCl4)-induced increase of serum glutamic-pyruvic transaminase (ALT) and elevation of MDA in liver of mice are significantly lowered by Phyllanthus urinaria in vivo, and the coincubation of isolated rat hepatocytes with Phyllanthus urinaria in vitro significantly inhibits CCl4-induced decrease of mobility of membrane of liver cells and increase of intracellular free Ca2+ ([Ca2+]i) concentrations of liver cells. These results suggest that the anti-lipid peroxidation effect and protective action of membrane of Phyllanthus urinaria may be related to its protective action against CCl4-induced liver injuries.

Alanine Transaminase↗
PubMed1997

[Pharmacological study on magnetite].

Magnetite can markedly inhibit the rodent turn-around reaction induced by acetic acid, reduce the threshold dose of pentobarbital sodium and shorten rodent's incubation period of falling asleep. It has also the following effects; antagonizing metrazol which causes rodent convulsions, postponing the incubation period of being startled by Huisuling, cutting down the extent of rodent's foot swells caused by JCCJ, and diminishing bleeding time and congulating time.

Analgesics↗
PubMed1997

[Effect of retinoic acids on phosphatidylcholine specific phospholipase D in 7721 human hepatocarcinoma cell line].

In order to elucidate the relation between cell signal transduction and cell differentiation, the effect of two differentiation inducers--all trans-retinoic acid (ATRA) and 13 cis-retinoic acid (13 cis-RA) on the specific activities (nmol/hr.mg protein) of phosphatidyl choline specific phospholipase D (PC-PLD) in 7721 human hepatocarcinoma cell line was studied. It was found that ATRA and 13 cis-RA increased the specific activities of membrane bound PC-PLD on 2nd and 4th day of cell culture respectively. If the PC-PLD activities were calculated as activity per bottle cells, the effect of ATRA on the 2nd day was also higher than that of 13 cis-RA, while the reverse was true on the 4th day, revealing a postponed effect of 13 cis-RA as compared with ATRA. The increase of PC-PLD was higher when the culture medium was refreshed every day than that when the medium was unrefreshed, suggesting that a factor might be existed in the fresh medium which could enhance the stimulating effect of retinoic acids on PC-PLD. The effect of ATRA on PC-PLD specific activity were higher on 2nd day than that on 4th day, owing to the accelerated proliferation of the cells on 4th day, leading to the increase of protein contents and decrease of the enzyme specific activity calculated on the base of protein contents. Whereas, the effect of 13 cis-RA on PC-PLD specific activity were higher on 4th day than that on 2nd day, because the increase of enzyme activity was higher than the increase of protein contents on 4th day. The relation between the elevation of PC-PLD and protein kinases was further studied and discovered that ATRA decreased both the specific activities of membrane bound and cytosolic protein kinase C (PKC) as well as tyrosine protein kinase (TPK) either in 2nd or 4th day of cell culture, which indicated that the increasing effect of ATRA on membrane bound PC-PLD was not resulted from the stimulating effect of PKC and TPK on PC-PLD, and its mechanism remains to be further investigated.

Antineoplastic Agents↗