Biomedical subjects

T J Wang

Publications and source records attributed to T J Wang.

At least 55 records · Page 3Linked to original sources

PubMed1997

[Studies on the chemical constituents of Gynostemma longipes C.Y. Wu].

A new triterpenoid saponin named gylongiposide I was isolated from the aerial parts of Gynostemma longipes C.Y. Wu. On the basis of chemical evidence and spectral data the structure of gylongiposide I was elucidated as 19-oxo-3 beta, 20(S), 21-trihydroxydammar-24-ene-3-O-([alpha-L-rhamnopyranosy(1-->2)] [beta-D-xylpyranosyl(1-->3)]) alpha-L-arabinopyranoside (G). The known compounds were identified as gypenoside XLIX(F) and ginsenoside Rb1(A).

Drugs, Chinese Herbal↗

PubMed1996

Dual monoclonal antibody immunoassay for free prostate-specific antigen.

Prostate-specific antigen (PSA) is the most important tumor marker for early detection and monitoring of prostate cancer (PCa) patients. PSA is also elevated in many patients with benign prostatic hyperplasia (BPH). The study of the serum PSA forms, free PSA (f-PSA) and PSA complexed with alpha 1-antichymotrypsin (PSA-ACT), may improve the discrimination between PCa and BPH. An immunoassay specific for f-PSA is reported with very low cross-reactivity (0.7%) to PSA-ACT. Serum specimens from BPH and PCa patients (determined by biopsy) with PSA levels from < 1 to > 100 ng/ml were tested. No f-PSA was detected in serum specimens from normal females (N = 50). Low levels (0-0.3 ng/ml) were detected in specimens from healthy males (N = 60). In specimens from PCa and BPH patients, the f-PSA to total PSA ratio (f/t) was found to range from 1% to higher than 60%. While maintaining an 80% sensitivity for cancer, the f/t ratio improved specificity to approximately 80%, as compared to 55% for total PSA alone. The receiver operating characteristics (ROC) curve analysis of the f/t ratio displayed a greater area under the plot (0.84) compared to total PSA alone (0.745). The results demonstrate that the f/t ratio significantly increases specificity for PCa detection compared to total PSA alone, showing the potential clinical value of the f-PSA immunoassay.

Adult↗

PubMed1996

Lung cancer in nonsmoking Chinese women: a case-control study.

The risk factors for lung cancer in lifetime nonsmoking women were investigated in a hospital-based case-control study in the urban area of Shenyang, China, between April 1992 and May 1994. One-hundred thirty-five newly-diagnosed lung cancer cases and an equal number of controls, matched for age and sex, were enrolled and interviewed by trained personnel who administered a standardized questionnaire. The histopathological cell type was predominantly adenocarcinoma (54.5%), followed by small cell carcinoma (20%), squamous cell carcinoma (16.4%), and others (9.1%). The data were analyzed using the Mantel-Haenszel method and by multivariate logistic regression analysis. The odds ratio (OR) and confidence interval (CI) associated with cooking oil vapors and with family history of cancer were 3.79 (95% CI, 2.29-6.27) and 2.29 (95% CI, 1.01-5.17), respectively. No association was found between exposure to environmental tobacco smoke (ETS), presence of previous lung diseases, and "kang" use. Cooking practices, exposure to cooking fumes, and a family history of cancer were found to significantly increase the risk of lung cancer.

Adult↗

PubMed1995

Evaluation of percentage of free serum prostate-specific antigen to improve specificity of prostate cancer screening.

OBJECTIVE: To evaluate measurement of percentage of free prostate-specific antigen (PSA) in serum to improve the specificity of prostate cancer screening in men with serum PSA levels between 4.1 and 10.0 ng/mL. DESIGN: Retrospective, nonrandomized analysis using a research assay for measuring free PSA in frozen serum from men with a spectrum of prostate sizes and digital rectal examination results. SETTING: General community outpatient prostate cancer screening program at a university center. PATIENTS: One hundred thirteen men aged 50 years or older, 99% of whom were white, with serum PSA concentrations of 4.1 to 10.0 ng/mL, including 63 men with histologically confirmed benign prostatic hyperplasia, 30 with prostate cancer with an enlarged gland, and 20 with cancer with a normal-sized gland. All study volunteers had undergone prostatic ultrasonography and biopsy. MAIN OUTCOME MEASURES: Percentage of free PSA in serum and percentage of free PSA cutoff that maintained at least 90% sensitivity for prostate cancer detection. RESULTS: Median percentage of free PSA was 9.2% in men with cancer and a normal-sized gland, 15.9% in men with cancer and an enlarged gland, and 18.8% in men with benign prostatic hyperplasia (P < .001). The percentage of free PSA cutoff was higher in men with an enlarged gland and in those with a palpably benign gland. In men with an enlarged, palpably benign gland, a free PSA cutoff of 23.4% or lower detected at least 90% of cancers and would have eliminated 31.3% of negative biopsies. CONCLUSIONS: Measurement of percentage of free serum PSA improves specificity of prostate cancer screening in selected men with elevated total serum PSA levels and can reduce unnecessary prostate biopsies with minimal effects on the cancer detection rate; however, further studies are needed to define optimal cutoffs. Final evaluation of PSA screening also must consider the ability of current treatments to improve the prognosis of screen-detected prostate cancer.

Aged↗

PubMed1995

Stimulation of myofibrillar protein synthesis in hindlimb suspended rats by resistance exercise and growth hormone.

The objective of this study was to determine the ability of a single bout of resistance exercise alone or in combination with recombinant human growth hormone (rhGH) to stimulate myofibrillar protein synthesis (Ks) in hindlimb suspended (HLS) adult female rats. Plantar flexor muscles were stimulated with resistance exercise, consisting of 10 repetitions of ladder climbing on a 1 m grid (85 degrees), carrying an additional 50% of their body weight attached to their tails. Saline or rhGH (1 mg/kg) was administered 30' prior to exercise, and Ks was determined with a constant infusion of 3H-Leucine at 15', 60', 180', and 360' following exercise. Three days of HLS depressed Ks approximately 65% and 30-40% in the soleus and gastrocnemius muscles, respectively (p < or = 0.05). Exercise increased soleus Ks in saline-treated rats 149% 60' following exercise (p < or = 0.05), decaying to that of non-exercised animals during the next 5 hours. Relative to suspended, non-exercised rats rhGH+exercise increased soleus Ks 84%, 108%, and 72% at 15', 60' and 360' following exercise (p < or = 0.05). Gastrocnemius Ks was not significantly increased by exercise or the combination of rhGH and exercise up to 360' post-exercise. Results from this study indicate that resistance exercise stimulated Ks 60' post-exercise in the soleus of HLS rats, with no apparent effect of rhGH to enhance or prolong exercise-induced stimulation. Results suggests that exercise frequency may be important to maintenance of the slow-twitch soleus during non-weightbearing, but that the ability of resistance exercise to maintain myofibrillar protein content in the gastrocnemius of hindlimb suspended rats cannot be explained by acute stimulation of synthesis.

Animals↗

PubMed1995

Molecular forms of prostate-specific antigen and the human kallikrein gene family: a new era.

Without question, much has been learned about the glycoprotein PSA in recent years. By increasing our understanding of this tumor marker's biochemical and physiologic properties, we will be able to improve its clinical utility. The discovery of the various molecular forms of PSA represents a significant advancement. Knowing the concentration and ratio of these PSA forms will be valuable in deciding which patients require further evaluation with transrectal ultrasound and prostate biopsy and which men can be monitored safely without undergoing further invasive testing. This information will be most valuable in treating the patient with a mildly elevated serum PSA level. Although assays are not yet available to detect specifically hK2, the striking similarities of hK2 to PSA, including selective expression in the prostate, suggest that this marker may also prove useful in prostate cancer management. Indeed, a new era of PSA testing has been entered, and the entire field of prostate cancer will benefit.

Amino Acid Sequence↗

PubMed1995

The use of arch index to characterize arch height: a digital image processing approach.

Attempts to evaluate foot arch types from footprint parameters have yielded conflicting results in the past. This could be caused by the uncertainty inherent in the definition of some footprint parameters and the inaccuracy during the footprint acquisition and the parameter calculation phases of the traditional methods. In order to avoid these problems, digital image processing methods were used to acquire and to calculate the Arch Index (AI), a parameter which is robust in its definition. A significant correlation (r = -0.70, p < 0.0001) was found between AI and arch height. Therefore this study confirms that foot arch type does correlate with the footprint parameter, AI. This was further revealed by a new parameter, the Modified Arch Index (MAI), which incorporates foot pressure information in the evaluation. MAI not only correlated well with arch height (r = -0.71, p < 0.0001) but appeared to characterize abnormal foot types better than AI.

Adult↗

PubMed1993

Classification of deep burn injuries--analyses of 117 cases.

A new system of classification, index of deep burn injuries (IDBI), was proposed in this paper. Using this system, we investigated 304 burn sites in 117 cases, of which 94.1% were repaired with the GCM with a satisfactory result. The IDBI of the 304 burn sites is in direct proportion to the severity and extent of burn injury and inverse ratio to the results. Analyses performed in this group suggested that the IDBI has many significances, which include: 1, making a correct diagnosis; 2, providing decided repair indications; 3, indicating the prognosis; 4, providing a reliable method for further investigation in the burn field. The standard of IV degree burn is equal to or more than 2 of IDBI.

Adolescent↗

PubMed1992

[Quality assessment of the traditional Chinese medicine gentian by chemical pattern recognition].

Methanol extracts of 38 samples of the traditional Chinese medicine gentian of different origin were prepared. Data reflecting their chemical constituents as a whole were obtained by HPLC. The Chinese Pharmacopoeia (1990) specified four species of the getiana as authentic. Some samples from the authentic and non-authentic gentian were used as the training set of pattern recognition. Chemical features of the gentian samples were selected from among the matching data of HPLC by the SIMCA program. Finally, the selected chemical features were displayed as stars in a semicircular polar coordinate system, resulting in a constellation graph. Quality assessment of the traditional Chinese medicine gentian was accomplished by recognizing the position and path of the stars in the constellation graph. The clusters of the gentian samples in the constellation graph obtained from the HPLC features were consistent with and complement to their plant taxonomy. The vivid graph demonstrated that pattern recognition via chemical constellation promises well a reliable method for assessing traditional Chinese medicines.

Chromatography, High Pressure Liquid↗

PubMed1991

[Home-made straight needle for anastomosis of posterior urethra].

We designed and made a straight needle for the anastomosis of the posterior urethra. From 1983 to 1989, eleven patients with stricture of the posterior urethra were treated with the needle. Follow-up for 3 to 6 months showed that satisfactory results were obtained in all the patients. With the straight needle, the catgut may be led outside or inside the bladder easily through suprapubic incision, may minimize the damage to bladder mucosa and increase the success rate of operation.

Adolescent↗

PubMed1990

Repair of experimental high voltage electrical injuries.

Repair methods for high voltage electrical injury were studied in 46 rats submitted to symmetrical bilateral hind limb electrical injuries using 1,600 V AC. Out of 40 hind limbs of the 40 rats which were treated with conservative debridement and flap coverage, 20 limbs repaired prior to the 48th post-injury hour obtained a good appearance and functions, the rest operated after the 4th post-injury day showed partial or complete disability. Forty contralateral limbs served as controls, including 20 hind limbs grafted with mesh-grafts which recently necrotized and 20 of them debrided thoroughly resulting in substantial loss of tissue, showed disabling effects. The investigation suggested that a better appearance and functions in such injuries would be obtained if using the technique of immediate conservative debridement and flap coverage.

Animals↗

PubMed1990

Urgent repair of electrical injuries: analysis of 40 cases.

40 patients suffering from electrical injuries were rehabilitated using a new system of urgent conservative debridement and flap coverage in the period from October 1984 to July 1988. For this purpose, a 1-4 year follow-up was needed. Good appearance and functions of the extremities or organs were obtained and the amputation rate was lower (7.5%) than that used in patients treated with traditionally conservative methods (47.7% in the same hospital.

Adolescent↗

PubMed1990

Increasing flap survival: a new method.

A new method of continuous irrigation beneath a flap with special irrigation was designed to attempt to improve flap survival in 42 animals. In each animal experimental and control flaps were symmetrically designed using two flanks or limbs (total number of flaps, 154). The flap length survival in the 77 experimental flaps ranged from 18 to 88% greater than that in the control flaps. Bacterial cultures of the secretions from all flaps suggested that this method has a practical value in preventing and controlling the infections that would result in flap necrosis.

Animals↗

PubMed1989

Suppression of sensitivity to surround displacement during vergence eye movements.

Suppression was investigated psychophysically in three human observers by measuring their loss of sensitivity to brief (20 ms) simultaneous vertical displacement (up to 0.5 degrees) of horizontal lines during 4 degrees convergence eye movements. A two-alternative forced choice procedure was used in which the stimulus was presented either in the first or second portion of a trial. The amplitude of the displacement pulse, the time of the pulse relative to convergence onset, and the portion of a trial in which the stimulus was presented were randomized. The results showed that suppression began about 200 ms before, and continued until 350 ms after, convergence onset with maximum loss occurring at 25 to 125 ms after convergence onset. The maximum sensitivity loss was about 0.25 to 0.30 log units. Since peripheral factors were minimized by the use of a brief stimulus presentation and an eccentrically placed surround, the suppression found was primarily attributed to central neural mechanisms. Finally, the suppression of sensitivity to pulse displacement during the initial phase of the vergence movement is consistent with a recently developed dual-mode model of the vergence system, in which the initial transient portion of a step response is preprogrammed whereas the final sustained portion is maintained by continuous feedback control.

Choice Behavior↗

PubMed1987