Biomedical subjects

L Y Wang

Publications and source records attributed to L Y Wang.

At least 19 recordsLinked to original sources

PubMed1992

The role of hepatitis B and C viruses in hepatocellular carcinoma in a hepatitis B endemic area. A case-control study.

To investigate the role of hepatitis B (HBV) and C viruses (HCV) in hepatocellular carcinoma (HCC) in an HBV endemic area and elucidate the interaction of these two viruses, a case-control study of 128 patients with HCC and 384 age-matched and sex-matched control subjects was done. The positive rates of hepatitis B surface antigen (HBsAg, 77.3%, 99 of 128) and anti-HCV (19.5%, 25 of 128) in patients with HCC were significantly higher than in control subjects (P less than 0.001). Both HBsAg and anti-HCV were important risk factors for HCC (relative risks, 13.96 and 27.12, respectively), and the risk for HCC was elevated significantly to 40.05 (95% confidence interval, 12.57 to 127.6) when HBsAg and anti-HCV were considered simultaneously. These results suggested that HBV and HCV were associated highly with HCC in an HBV endemic area and that these two viruses might contribute independent but synergistic effects to the pathogenesis of HCC.

Adult↗

PubMed1992

Treatment of hepatocellular carcinoma by transcatheter arterial chemoembolization and analysis of prognostic factors.

A total of 100 patients with histologically proven hepatocellular carcinoma (HCC) underwent transcatheter arterial chemoembolization (TACE) and were followed for more than 1 year and 10 months. Portal vein branch thrombosis was diagnosed in 14 patients, and extrahepatic metastasis was noted in 11 subjects. The embolization material used was iodized oil (0.1-0.2 ml/cm tumor area at its maximal diameter), which was prepared by pumping with contrast agent and then mixed with anticancer drugs; Gelfoam particles measuring 1-2 mm in size were subsequently injected. The overall cumulative 0.5- 1-, 2-, and 3-year survival rates were 81%, 57%, 31%, and 21%, respectively. Patients with an intact capsule and those with solitary lesions, especially when the tumor diameter was < 5 cm, achieved a higher survival rate. In contrast, incomplete TACE, extrahepatic metastasis, and portal vein thrombosis were associated with the worst outcome. Patients with positive HBsAG and diffuse or multiple tumors also showed a poor outcome. Early diagnosis and early treatment of HCC are the keys for the achievement of better clinical results.

Adult↗

PubMed1992

Radiotherapy in the treatment of hepatocellular carcinoma and its metastases.

A study was conducted to evaluate the effect of external radiation therapy on hepatocellular carcinoma (HCC) and its metastatic lesions. A total of 33 patients with cytopathologically proven HCC were subjected to radiation therapy over a 4-year period, and treatment was discontinued in 8 cases due to jaundice, severe discomfort, or early mortality. Thus, 25 patients with 28 lesions underwent irradiation with a total dose ranging between 3000 and 5600. Of these, seven were irradiated for liver tumors, and the results showed that two lesions decreased in size, the symptoms improved in 1 case, and another patient maintained stable disease for 4 months. Among the 21 metastatic lesions treated, only 2 patients failed respond to the treatment. Nine subjects were irradiated for bone metastases, and the bone pain subsided in all but one case. The survival for bone metastasis was as long as 23 months when the primary tumor was treated effectively. Three of the four cases of irradiated skin nodules disappeared and had not recurred after 5 months, 1 year, and 4 years, respectively. Tumor shrinkage or symptoms of relief were noted for three abdominal lymph nodes, one neck lymph node, one pleural tumor, and one lung tumor. Clinical improvement associated with a stable lesion was observed in two patients with brain metastasis. Follow-up revealed regrowth of the tumor or recurrence of symptoms in most of the patients. However, none of the patients died as a direct result of a metastatic lesion. Although external radiation therapy is palliative in intent, it appears to be useful in the treatment of HCC and its metastatic lesions.

Adult↗

PubMed1992

Sensory nerve endings in the puborectalis and anal region of the fetus and newborn.

The study was carried out in seven fetuses (ovulation ages were 16, 18, 20, 22, 26, 28, and 31 weeks, respectively) and in five full-term newborn babies. The modified Bielschowsky method and Barker's block silver impregnation were used. It was found that the muscle spindle was arranged in the puborectalis and the external sphincter muscles from the 20th week onward; the tendon organ was located in association with the musculo-tendinous junction of the puborectalis from the 20th week onward; the Pacinian corpuscle lay in the plane of cleavage between the internal anal sphincter and the external anal sphincter from the 22nd week onward, and in the presacral space from the 28th week onward, and the later lagged behind the former in development; the globular endings lay in the presacral space from the 28th week onward; and the free nerve ending was distributed in the epithelium of the anal mucosa and the epidermis around the anus from the 31st week onward. These sensory nerve endings tend to mature gradually with increasing age. It was concluded that these endings may be responsible for the reflex of the external anal sphincter and the anal sensation.

Anal Canal↗

PubMed1992

State dependent spike detection: validation.

We present a formal validation of the method of state dependent spike detection; its principle and initial results were given in Gotman and Wang (1991). The method utilizes different procedures for elimination of non-epileptic transients according to state (active or quiet wakefulness, sleep stages); it also varies detection sensitivity according to state. Twenty new 100 min recordings were obtained from 20 unselected patients, covering active wakefulness, quiet wakefulness and various sleep stages. Results indicated that, while the total number of detections was reduced by 15%, true detections increased by 39% and false detections decreased by 60%. This significant improvement is due to the fact that wave morphology is now considered within its spatial context and particularly within a wide temporal context.

Adolescent↗

PubMed1992

The transport barrier of epithelia: a comparative study on membrane permeability and charge selectivity in the rabbit.

The transport barrier of the epithelial presents one of the major problems limiting the effective use of these tissues as alternate delivery routes for macromolecules such as peptides and proteins. In the present study, two membrane transport properties, namely, the permeability and permselectivity of the shunt pathway, were investigated and compared in various tissues including the nasal, tracheal, bronchial, buccal, rectal, vaginal, corneal, epidermal, duodenal, jejunal, ileal, and colonic epithelia. Membrane permeability was evaluated using a combined method based on electrical conductance and flux measurements of a hydrophilic fluorescent probe, 6-carboxy fluorescein (CF). Membrane permselectivity or the charge discriminating ability of the membrane was evaluated by KCl diffusion potential measurements. The results indicate that all epithelia under investigation possess a relatively high degree of permeation barrier and are highly selective for the absorption of positively charged solutes. Shunt path permeability was found to vary greatly among tissues from different epithelia, whereas membrane charge selectivity was relatively constant in these tissues. A good correlation was observed between membrane electrical conductance and steady-state flux of CF, indicating a paracellular transport of the compound. The rank order of the intrinsic membrane permeability was as follows: intestinal approximately nasal greater than or equal to bronchial greater than or equal to tracheal greater than vaginal greater than or equal to rectal greater than corneal greater than buccal greater than skin. Membrane permselectivity, expressed as the ratio of transport number (positive over negative), ranges from 1.78 for the buccal to 1.33 for the rectal epithelium.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Duplex pulsed Doppler sonography in the differential diagnosis of hepatocellular carcinoma and other common hepatic tumours.

180 previously untreated consecutive patients with liver tumours (308 lesions), including 104 hepatocellular carcinomas (148 lesions), 43 metastases (116 lesions) and 33 haemangiomas (44 lesions), were studied to determine the value of duplex sonography in the differentiation of hepatocellular carcinoma from other tumours. For lesions measuring less than or equal to 5 cm in diameter, hepatocellular carcinoma demonstrated the highest rate and haemangioma demonstrated the lowest rate of Doppler signals from within the lesions. To differentiate malignancy from haemangioma, the presence or absence of Doppler signals from these lesions were used as criteria. The specificity and positive predictive value were very high (100%, 100%), but the sensitivity, negative predictive value and accuracy were low (61.5%, 48.3%, 71.7%, respectively). With one exception, all lesions measuring less than 3 cm in diameter with detectable Doppler signals were hepatocellular carcinoma. Using these results it is possible to differentiate hepatocellular carcinoma from metastases and haemangioma with high sensitivity, specificity, positive and negative predictive value, and accuracy (80.8%, 96.4%, 95.5%, 84.4%, 88.9%, respectively, for metastases; 80.8%, 100%. 100%, 81.5%, 89.6%, respectively, for haemangioma). We conclude that Doppler signals from within a lesion in combination with its size can aid differentiation of hepatocellular carcinoma from two other kinds of common hepatic tumour.

Adult↗

PubMed1992

Clinical utility of pulsed Doppler in the detection of arterioportal shunting in patients with hepatocellular carcinoma.

Ninety-seven patients with hepatocellular carcinoma had duplex scanning from the patent or residual portal lumen and comparative angiography. Duplex ultrasonography identified five of nine patients with angiographic evidence of arterioportal shunting. Furthermore, Doppler results indicated the presence of the shunt in one patient without angiographic evidence. Duplex scanning from the portal lumen may be useful in the detection of arterioportal shunting. This procedure can be used to evaluate the hemodynamic change of the recipient portal vein under natural physiologic conditions. However, small shunts without hepatofugal portal blood cannot be detected by this procedure.

Adult↗

PubMed1992

Effects of exogenous gamma-aminobutyric acid on experimental arrhythmias.

The effects of exogenous gamma-aminobutyric acid (GABA) 10 mg.kg-1 iv in preventing arrhythmias induced by drugs and ischemia were studied in mice, rats, and guinea pigs. It was found that the threshold dose of aconitine inducing arrhythmia in mice and the recovery rate to normal sinus rhythm increased significantly, ED50 of GABA was 5.4-5.8 mg.kg-1. The duration of ventricular tachycardia (VT) induced by aconitine in rats was shortened (P < 0.01). The incidence and the mortality of ventricular fibrillation (VF) in GABA group were decreased to 0/10 vs 6/10 and 5/10 in control, respectively (P < 0.05). The doses of ouabain to induce ectopic beats (EB), VT, VF, and cardiac arrest (CA) in guinea pigs were increased (P < 0.01). The incidence of VF induced by coronary artery ligation in rats was decreased to 0/5 in GABA group vs 4/5 in control group (P < 0.01). The total amount of EB, total time of VT, and VF were 66%, 41%, and 0% of the control group, respectively. The anti-arrhythmic effects of GABA were dose-dependent and as potent as procainamide (10 or 5 mg.kg-1, iv). The results suggest GABA (10 mg.kg-1, iv) may be useful for the prevention of VT and VF.

Aconitine↗

PubMed1991

The single cysteine residue on an alpha family chick liver glutathione S-transferase CL 3-3 is not functionally important.

Chick liver glutathione S-transferase CL 3-3, expressed using a baculovirus system in Spodoptera frugiperda (SF9) cells, contains a single cysteine residue per subunit. This enzyme was modified with iodoacetamide. Amino acid analysis indicates that 0.85 +/- 0.10 cysteine residue was modified per enzyme subunit. GST CL 3-3 modified with iodo[14C]acetamide was further digested with trypsin and the isotope-labelled fragments were isolated. The fragment containing the cysteine residue accounts for 53% of the total labels. The S-carbaminomethylated protein retains the glutathione conjugating activity. Therefore, the cysteine residue is not essential for the enzymatic activity of CL 3-3.

Amino Acid Sequence↗

PubMed1991

Regulation of kainate receptors by cAMP-dependent protein kinase and phosphatases.

In the mammalian central nervous system, receptors for excitatory amino acid neurotransmitters such as the alpha-amino-3-hydroxy-5-methyl-4- isoxazolepropionic acid (AMPA)-kainate receptor mediate a large fraction of excitatory transmission. Currents induced by activation of the AMPA-kainate receptor were potentiated by agents that specifically stimulate adenosine 3',5'-monophosphate (cAMP)-dependent protein kinase A (PKA) activity or were supported by intracellular application of the catalytic subunit of PKA by itself or in combination with cAMP. Furthermore, depression of these currents by a competitive inhibitor of PKA indicates that AMPA-kainate receptors are regulated by endogenous PKA. Endogenous protein phosphatases also regulate these receptors because an inhibitor of cellular phosphates enhanced kainate currents. Modulation of PKA and phosphatases may regulate the function of these receptors and thus contribute to synaptic plasticity in hippocampal neurons.

Animals↗

PubMed1991

Natural killer cell activity in patients with liver cirrhosis relative to severity of liver damage.

To evaluate the role of severe liver damage on natural killer cell activity, 29 patients with liver cirrhosis were examined. The natural killer cell activity was measured with a 4-hr chromium release assay, and the K562 cell line was employed as target cells. The natural killer cell activity was significantly decreased in cirrhotic patients compared with normal controls and patients with chronic active hepatitis. Cirrhotic patients with Pugh's C grade of severity of liver disease had lower natural killer cell activity. The depression of natural killer cell activity in cirrhotic patients was inversely correlated with prothrombin time ratios, and the natural killer cell activity in cirrhotic patients with hepatic encephalopathy was lower than in patients without hepatic encephalopathy. Thus, the diminished natural killer cell activity in cirrhotic patients might be related to the severity of liver damage.

Female↗

PubMed1991

Systemic amyloidosis presenting as splenic tumor.

We report a case of amyloidosis manifesting as a splenic tumor and pleural effusion. Only one case of a splenic amyloid tumor has been reported in the literature, but its radiological findings were not described. Therefore, we present the computed tomographic (CT), sonographic, and angiographic features of splenic amyloid tumor.

Amyloidosis↗

PubMed1991

State-dependent spike detection: concepts and preliminary results.

In traditional methods of spike detection, spikes are defined in absolute terms (duration, amplitude) or relative to a few seconds of background. These methods result in many false positive detections during long-term epilepsy monitoring because of numerous artefacts and non-epileptic transients. To reduce significantly false detection, we propose to render spike detection sensitive to the state of the EEG. We thus defined 5 states (active wakefulness, quiet wakefulness, desynchronized EEG, phasic EEG and slow EEG) and designed a method for automatic state classification. We then designed procedures for identification of non-epileptic transients (eye blinks, EMG, alpha, spindles, vertex sharp waves). These procedures are to be applied only in the state in which they are likely to occur (e.g., eye blinks in wakefulness). We present preliminary results from 14 recordings each lasting 100 min, which indicate a state classification reliability of 85-90%, reduction in false detection of 65-90% if state classification were perfect; true spikes lost as a result of these procedures were under 5%. These results are encouraging and validate the concept of a spike detection system which analyses a wide temporal and spatial context before deciding the significance of a wave form.

Blinking↗

PubMed1991

Duplex pulsed Doppler sonography of hepatocellular carcinoma treated with transcatheter arterial embolization.

Thirty-one patients with hepatocellular carcinoma underwent duplex scanning of their lesions with comparative angiography and serum alpha-fetoprotein determinations before and after transcatheter arterial embolization. Duplex ultrasound correctly identified 26 patients with patent tumor vessels after embolization. The Doppler signals became undetectable after embolization in the other five patients. Comparative angiography demonstrated good devascularization of their lesions. However, tiny tumor blush or small satellite nodules around the periphery of the devascularized masses were found. Therefore, the presence of signals after therapy indubitably needs further embolization. The timing of the second embolization for the patient with undetectable Doppler signals after the first embolization needs to be justified by further evaluations.

Adult↗

PubMed1991

Duplex pulsed Doppler sonography of portal vein thrombosis in hepatocellular carcinoma.

Sixteen patients with hepatocellular carcinoma had duplex pulsed Doppler scanning of the portal thrombus and comparative angiography. Fifteen patients demonstrated detectable Doppler signals from the thrombus. The Doppler signals were corroborated by the "thread-and-streaks" sign on angiography in eight patients. This suggests that signals come from tumor vessels within the thrombus. Therefore, the presence of Doppler signals in the thrombotic portal venous system is not only due to partial obstruction of the lumen. Tumor thrombus from hepatocellular carcinoma must be considered, especially when the detectable signals are pulsatile waves.

Adult↗

PubMed1991

Comprehensive assessment of long-term postoperative continence in pediatric imperforate anus. Clinical, manometric and contrast studies.

109 patients with imperforate anus were followed up postoperatively for 5 to 28 years. Postoperative continence was evaluated by anorectal manometry, barium enema and clinical symptoms. A comprehensive assessment system, combining the clinical and objective systems was designed which can reflect postoperative anal continence function completely and objectively. It is useful for determining the causes of incontinence and its treatment.

Adolescent↗

PubMed1991

[Estrogen and progesterone receptors in esophageal carcinoma cells].

Distribution of estrogen and progesterone receptors (ER and PR) was studied in esophageal tissue (48 patients with esophageal carcinoma, 20 normal subjects and 12 fetuses) and Eca 109 cell line using enzyme-linking affinity immunohistochemistry method. In the meantime, plasma estradiol and progesterone levels were determined in 8 patients with esophageal carcinoma using radioimmunoassay method. The results showed that the positive rates of ER and PR in esophageal carcinoma were 43.75% (21/48) and 39.58% (19/48). Both ER and PR were positive in Eca 109 cell line whereas they were negative in the control groups. Sex and grade of cancer were the factors influencing the positive rates of ER and PR. It is indicated that carcinogenesis of esophageal carcinoma might be related to sex hormone metabolism. The measurement of ER and PR may be useful in clinical practice.

Adenocarcinoma↗