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Biomedical subjects

S M Wang

Publications and source records attributed to S M Wang.

At least 19 recordsLinked to original sources
PubMed2005

Cytological and biochemical studies of breast cyst fluid.

We determined the biochemical composition of fluid aspirated from 52 breast cysts and classified the cysts into types I and II on the basis of the potassium-to-sodium (K/Na) ratio in the fluid. In this study, we confirmed the presence of prostate-specific antigen (PSA) in some breast cyst fluids, regardless of whether cysts were type 1 or type 2, or benign or malignant. On immunohistochemical study, we found no direct correlation between the presence of PSA and progesterone receptors, which is at odds with the results of earlier reports. Current practice in cytologic study appears to favor the examination of bloody fluid. In this study, two samples found to contain malignant cells were cloudy or turbid. We therefore recommend that all cloudy or turbid cyst fluids should be subjected to cytologic examination. This study indicated that the potassium and sodium concentrations were not the same in multiple cysts in the same individuals. In addition, apocrine cells were observed in both type 1 and type 2 cysts. Therefore, breast cyst type cannot predict the natural history of cystic changes or indicate the likelihood of cancer. The finding of malignancy in two patients with type 2 cysts also supports this argument.

Adult↗
PubMed2005

Bioleaching of Cr from tannery sludge: the effects of initial acid addition and recycling of acidified bioleached sludge.

A technologically feasible process called bioleaching was used to remove Cr from tannery sludge with Acidithiobacilli TS6 bacteria in this study. The buffering capacity of tannery sludge and municipal sewage sludge were compared. The effects of initial sulfuric acid addition on bioleaching process and influences of recycle rate of acidified bioleached sludge on subsequent bioleaching reaction were examined. The quantities of initial sulfuric acid addition ranged from 0 to 0.185 ml g(-1) dry sludge. Recycle rate (V(beleached/V(total)) was controlled at 1/3, 1/2, 3/5 and 2/3. We found that tannery sludge had a higher buffering capacity than sewage sludge. The results showed that there was an increase in the rates of pH reduction and Cr solubilization with the increase of initial sulfuric acid addition. The suitable quantity of sulfuric acid addition was 0.185 ml g(-1) dry sludge at the beginning of the first bioleaching process. After 10 days of bioleaching, pH reached 1.5 and almost 100% of Cr could be leached in this case. Besides, an evidently dividing point pH 2.0 was found to be the threshold value for considerable Cr solubilization during the leaching reaction. Recycle experiments confirmed that the application of the method by recycling acidified sludge to launch subsequent bioleaching is feasible. The optimal recycle rate of acidified sludge for consecutive leaching of Cr from tannery sludge is 2/3.

Acidithiobacillus↗
PubMed2005

Molecular epidemiology of Mycobacterium tuberculosis in China: a nationwide random survey in 2000.

OBJECTIVE: To determine the contribution of the Mycobacterium tuberculosis (TB) Beijing genotype to the population structure of M. tuberculosis complex in China. DESIGN: Genotypes of 441 mycobacterial isolates were determined by spoligotyping and IS6110 restriction fragment length polymorphism (RFLP). The isolates were from a nationwide random survey for the epidemiology of TB conducted in 2000, and the drug susceptibility patterns and epidemiological data were known. RESULT: A total of 408 samples contained M. tuberculosis as determined by spoligotyping. Of the M. tuberculosis strains, 64.9% (265/408) were of the Beijing genotype. Using the chi-squared test, no statistically significant differences were observed in the proportion of Beijing genotype TB in patients of different sex, age or living in different areas of the country, but a significant difference was observed with multidrug-resistant (MDR) TB: 77.8% (42/ 54) of MDR isolates were of the Beijing genotype vs. 60.2% (213/354) of the drug-susceptible isolates. In the multivariate logistic regression model, the Beijing genotype was significantly associated with region and not with MDR. CONCLUSION: The M. tuberculosis Beijing genotype has prevailed in China for at least five decades and is associated with region.

Adolescent↗
PubMed2004

Decoy receptor 3 (DcR3) induces osteoclast formation from monocyte/macrophage lineage precursor cells.

Recent evidence indicates that the decoy receptor 3 (DcR3) of the TNF receptor superfamily, which initially though prevents cytokine responses of FasL, LIGHT and TL1A by binding and neutralization, can modulate monocyte function through reverse signaling. We show in this work that DcR3 can induce osteoclast formation from human monocytes, murine RAW264.7 macrophages, and bone marrow cells. DcR3-differentiated cells exhibit characteristics unique for osteoclasts, including polynuclear giant morphology, bone resorption, TRAP, CD51/61, and MMP-9 expression. Consistent with the abrogation of osteoclastogenic effect of DcR3 by TNFR-Fc, DcR3 treatment can induce osteoclastogenic cytokine TNF-alpha release through ERK and p38 MAPK signaling pathways. We conclude that DcR3 via coupling reverse signaling of ERK and p38 MAPK and stimulating TNF-alpha synthesis is a critical regulator of osteoclast formation. This action of DcR3 might play an important role in significant osteoclastic activity in osteolytic bone metastases.

Acid Phosphatase↗
PubMed2003

Clinicopathological and molecular biological features of colorectal cancer in patients less than 40 years of age.

BACKGROUND: The aim of the present study was to identify the clinicopathological and molecular biological characteristics of early-onset colorectal cancers. METHODS: The clinicopathological and molecular biological parameters of 138 consecutive patients with colorectal cancer aged less than 40 years were compared with those of 339 patients aged 60 years or more. RESULTS: The younger patients with colorectal cancer had more mucin-producing (14.5 versus 4.7 per cent; P < 0.001) and poorly differentiated (7.2 versus 3.3 per cent; P = 0.015) tumours, a higher incidence of synchronous (5.8 versus 1.2 per cent; P = 0.007) and metachronous (4.0 versus 0.6 per cent; P = 0.023) colorectal cancers, and more advanced tumour stage (P < 0.001) than older patients. The operative mortality rate was lower (0.7 versus 5.0 per cent; P = 0.026), and cancer-specific survival was similar (in stage I, II and III disease; P > 0.05) or better (in stage IV disease; 95 per cent confidence interval 22.50 to 28.41 versus 12.61 to 17.05 months; P < 0.001). There was a higher percentage of normal p53 expression (61.1 versus 46.8 per cent; P = 0.023) and high-frequency microsatellite instability (MSI-H) (29.4 versus 6.3 per cent; P < 0.001), and a similar family history of cancer (17.5 versus 14.2 per cent; P > 0.05), compared with older patients. CONCLUSION: Young patients with colorectal cancer have several distinct clinicopathological and molecular biological features. The mechanisms underlying the inconsistency between the presence of MSI-H and a family history of cancer in these early-onset colorectal cancers deserve further investigation.

Adolescent↗
PubMed2002

Long-term preservation of cortically dependent visual function in RCS rats by transplantation.

Cell transplantation is one way of limiting the progress of retinal degeneration in animal models of blinding diseases such as retinitis pigmentosa (RP) and age-related macular degeneration (AMD). Here we transplanted a human retinal pigment epithelial (RPE) cell line into the subretinal space of one such model, the Royal College of Surgeons (RCS) rat, and showed, using head tracking to moving stripes and pattern discrimination in conjunction with single-unit cortical physiology, that cortically mediated vision can be preserved with this treatment.

Animals↗
PubMed2002

The influence of artificial cutoff on a monitoring system and the water quality of the Keelung River.

The purpose of this study was to design a water quality monitoring network for the Keelung River in order to evaluate the effects of artificial cutoff across two bend channels. A steady-state water quality model was used to simulate the BOD and DO curves. The Kriging theory was applied to select the optimal locations for a water quality monitoring network. The sampling frequency was determined by the coefficients of variation of water quality and by considering the significance level and confidence interval. After calibration and verification of the water quality model, the model was applied and the simulation results indicated that the values of DO in the new channel would be higher than those of the old channel reaches. The critical point of the oxygen sag curve would shift to the mouth of river under O75 low-flow conditions, and the BOD values in the new channel would also slightly increase. The results further indicated that more monitoring stations would be needed in the downstream reaches.

China↗
PubMed2001

The pattern of gene expression in human CD34(+) stem/progenitor cells.

We have analyzed the pattern of gene expression in human primary CD34(+) stem/progenitor cells. We identified 42,399 unique serial analysis of gene expression (SAGE) tags among 106,021 SAGE tags collected from 2.5 x 10(6) CD34(+) cells purified from bone marrow. Of these unique SAGE tags, 21,546 matched known expressed sequences, including 3,687 known genes, and 20,854 were novel without a match. The SAGE tags that matched known sequences tended to be at higher levels, whereas the novel SAGE tags tended to be at lower levels. By using the generation of longer sequences from SAGE tags for gene identification (GLGI) method, we identified the correct gene for 385 of 440 high-copy SAGE tags that matched multiple genes and we generated 198 novel 3' expressed sequence tags from 138 high-copy novel SAGE tags. We observed that many different SAGE tags were derived from the same genes, reflecting the high heterogeneity of the 3' untranslated region in the expressed genes. We compared the quantitative relationship for genes known to be important in hematopoiesis. The qualitative identification and quantitative measure for each known gene, expressed sequence tag, and novel SAGE tag provide a base for studying normal gene expression in hematopoietic stem/progenitor cells and for studying abnormal gene expression in hematopoietic diseases.

3' Untranslated Regions↗
PubMed2001

Simultaneous supercritical fluid extraction and chemical derivatization for the gas chromatographic-isotope dilution mass spectrometric determination of amphetamine and methamphetamine in urine.

An in-situ supercritical fluid extraction (SFE) and chemical derivatization (ChD) procedure followed by gas chromatography-isotope dilution mass spectrometry (GC-MS) for the determination of amphetamines in urine is described and evaluated. While using celite as the SFE wet-support, the one-pot sample pretreatment procedure also employs ammonium water to alkalize the urine matrix that contains protonated amphetamine (AP) and methamphetamine (MA). The mean recoveries achieved by simultaneous SFE-ChD, i.e., 95% (RSD=3.8%) for AP and 89% (RSD=4.0%) for MA, are significantly better than the corresponding overall recoveries obtained upon stepwise SFE-ChD, suggesting the unreacted trifluoroacetic anhydride (TFA) in the former procedure has strengthened the extracting power of CO, fluid as has been evidenced by a control test. As to GC-MS analysis, the optimal qualitative ions and quantitative ions of the respective analytes were determined via a rigorous evaluation process. Thus, the regression calibration curves for AP and MA in urine are linear within 100 approximately 50,000 ng/ml, with correlation coefficients typically exceeding 0.999. The limits of detection determined by two methods for AP and MA vary from 19 to 50 ng/ml, and limits of quantitation from 21 to 100 ng/ml. Precisions calculated for the triplicate analyses of AP and MA in a 500-ng/ml spiked control, two real-case samples and two quasi real-case samples, respectively, using regression calibration are typically below 10%. The method is simple and reliable. It may serve as an alternative to the existing confirmatory protocol for forensic urine drug testing.

Amphetamines↗
PubMed2001

The pattern of gene expression in human CD15+ myeloid progenitor cells.

We performed a genome-wide analysis of gene expression in primary human CD15(+) myeloid progenitor cells. By using the serial analysis of gene expression (SAGE) technique, we obtained quantitative information for the expression of 37,519 unique SAGE-tag sequences. Of these unique tags, (i) 25% were detected at high and intermediate levels, whereas 75% were present as single copies, (ii) 53% of the tags matched known expressed sequences, 34% of which were matched to more than one known expressed sequence, and (iii) 47% of the tags had no matches and represent potentially novel genes. The correct genes were confirmed by application of the generation of longer cDNA fragments from SAGE tags for gene identification (GLGI) technique for high-copy tags with multiple matches. A set of genes known to be important in myeloid differentiation were expressed at various levels and used different spliced forms. This study provides a normal baseline for comparison of gene expression in myeloid diseases. The strategy of using SAGE and GLGI techniques in this study has broad applications to the genome-wide identification of expressed genes.

Biomarkers↗
PubMed2001

Mechanism of colchicine-induced steroidogenesis in rat adrenocortical cells.

Conflicting data for the effects of colchicine on cholesterol transport and steroidogenesis raise the question of the role of microtubules in cholesterol transport from the lipid droplet to mitochondria in steroidogenic cells. In this study, using corticosterone radioimmunoassay and immunofluorescence microscopy, we re-evaluated the effects of colchicine on hormone production and morphological changes of lipid droplets' and studied the signaling pathway involved in colchicine-induced steroidogenesis. Colchicine stimulated steroid production in a dose- and time-dependent manner. The structural integrity of both the microtubules and the lipid droplet capsule was destroyed by colchicine treatment. Disruption of the lipid droplet capsule occurred later than microtubule depolymerization. After cessation of colchicine treatment and a 3 h recovery in fresh medium, capsular protein relocated to the droplet surface before the cytoplasmic microtubule network was re-established. beta-lumicolchicine, an inactive analogue of colchicine, disrupted the capsule and increased hormone production without affecting microtubular structure. Thus, microtubule depolymerization is not required for the increase in steroid production and capsular disruption. To explore the signaling pathway involved in colchicine-induced steroidogenesis, we measured intracellular cAMP levels. Unlike ACTH, colchicine did not increase cAMP levels, suggesting that the cAMP-PKA system is not involved. Colchicine and ACTH had additive effects on corticosterone production, whereas colchicine and PMA did not, implying that part of the PKC signaling mechanism may be involved in colchicine-induced steroidogenesis. Cycloheximide, a protein synthesis inhibitor, completely inhibited colchicine-induced steroidogenesis and capsular disruption. These results demonstrate that the steroid production and lipid droplet capsule detachment induced by colchicine are both protein neosynthesis-dependent and microtubule-independent.

Adrenal Cortex↗
PubMed2001

Change in hepatitis A virus seroepidemiology in southern Taiwan: a large percentage of the population lack protective antibody.

Hepatitis A, the predominant reported etiologic form of viral hepatitis in Taiwan, continues to be a disease primarily of children and young adults. A seroepidemiologic study was performed to assess the seroprevalence of hepatitis A (HAV) antibodies in the southern Taiwan general population in 1998 and is compared with results of a similar study in 1992. A total of 948 subjects (477 male and 471 female) with ages ranging from 0.3 to 63 years were stratified into 14 age-specific groups. The presence of anti-HAV antibodies was detected using a commercially available radioimmunoassay. Fifteen percent of the subjects were positive for anti-HAV antibodies, which is lower than that in 1992 (P < 0.001). Seroprevalences were 14.1% for males and 22.6% for females (P = 0.006). The pattern of anti-HAV seroprevalence was distinguishable from that found in 1992; minimum seroconversion occurred at ages ranging from 1 to 30 years. Prevalence of seropositive subjects decreased markedly for the < 1, 13-15, 16-19, 20-24, 25-29, and 30-39 year age groups in comparing 1998 with 1992. The current study demonstrates a continuing decline in the prevalence of HAV among children, adolescents, and young adults. The findings can be ascribed to the improvement of socioeconomic status and modernization of environmental sanitation. As a consequence of this changing trend of endemicity and the resulting lack hepatitis A antibodies among the general population in Taiwan, the risk of sudden major outbreaks is increased because of increasing international travel and immigration, particularly during and after natural disasters. HAV vaccination will be important for the prevention and control of HAV outbreaks in the community.

Adolescent↗
PubMed2001

The pattern of gene expression in mouse Gr-1(+) myeloid progenitor cells.

To understand the pattern of gene expression in mouse myeloid progenitor cells, we carried out a genome-wide analysis of gene expression in mouse bone marrow Gr-1(+) cells using SAGE and GLGI techniques. We identified 22,033 unique SAGE tags with quantitative information from 73,869 collected SAGE tags. Among these unique tags, 64% match known sequences, including many genes important for myeloid differentiation, and 36% have no matches to known sequences and are likely to represent novel genes. We compared the expression of mouse Gr-1(+) and human CD15(+) myeloid progenitor cells and showed that the pattern of gene expression of these two cell populations had some similarities. We also compared the expression of mouse Gr-1(+) myeloid progenitor cells with that of mouse brain tissue and found a highly tissue-specific manner of gene expression in these two samples. Our data provide a basis for studying altered gene expression in myeloid disorders using mouse models.

Animals↗
PubMed2001

Auricular acupuncture: a potential treatment for anxiety.

Acupuncture can be an effective treatment for chronic anxiety disorders. The purpose of this study was to assess the effectiveness of acupuncture in reducing anxiety in a volunteer population. If found effective, this modality could be introduced as a treatment of anxiety before surgery. Adult volunteers (n = 55), were randomized to three treatment groups: a) Shenmen group--bilateral auricular acupuncture at the "shenmen" point; b) Relaxation group-bilateral auricular acupuncture at a "relaxation" point; and c) Sham group-bilateral auricular acupuncture at a "sham" point. Press-acupuncture needles were inserted at the respective auricular areas for 48 h. State anxiety, blood pressure, heart rate, and electrodermal activity were assessed at 30 min, 24 h, and 48 h after insertion. Analyzing anxiety levels using repeated-measures analysis of variance has demonstrated a significant difference [F (2,51) =8.8, P = 0.001] between the three treatment groups. Post hoc analysis demonstrated that patients in the Relaxation group were significantly less anxious at 30 min (P = 0.007) and 24 h (P = 0.035) as compared with patients in both the Shenmen group and the Sham group, and less anxious at 48 h (P = 0.042) as compared with patients in Shenmen group. Repeated-measures analysis of variance performed for electrodermal activity, blood pressure, and heart rate demonstrated no group differences (P = ns). We conclude that auricular acupuncture at the "relaxation" point can decrease the anxiety level in a population of healthy volunteers.

Acupuncture Therapy↗
PubMed2001

Sensory stimuli and anxiety in children undergoing surgery: a randomized, controlled trial.

UNLABELLED: We assessed the effectiveness of a behavioral intervention aimed at reducing the anxiety of children undergoing anesthesia and surgery. The intervention consisted of dimmed operating room (OR) lights (200 Lx) and soft background music (Bach's "Air on a G String," 50-60 dB). Only one person, the attending anesthesiologist, interacted with the child during the induction of anesthesia. Children undergoing anesthesia and surgery were randomly assigned either to a low sensory stimulation group (LSSG, n = 33) or to control group (n = 37). By using validated behavioral measures of anxiety (mYPAS) and compliance (ICC), children were evaluated at the preoperative holding area and during the induction of anesthesia. On postoperative Days 1, 2, 3, 7, and 14, the behavioral recovery of the children was assessed by using the Post Hospitalization Behavior Questionnaire. We found that the LSSG was significantly less anxious compared with the control group on entrance to the OR (P = 0.03) and on the introduction of the anesthesia mask (P = 0.003). Also, the compliance during the induction of anesthesia was significantly better in children assigned to the LSSG (P = 0.02). The incidence of postoperative behavioral changes, however, did not differ significantly between the two groups (P = ns). We conclude that children who are exposed to low-level sensory stimuli during the induction of anesthesia and who are exposed to background music exhibit lower levels of anxiety and increased compliance. IMPLICATIONS: Children are less anxious and show increased compliance during induction when exposed to a single care-provider in a dimmed, quiet operating room with background music.

Adaptation, Psychological↗
PubMed2001

Structural studies of a yeast quaternary transcription-initiation complex.

A 96.7 kDa quaternary transcription-factor complex consisting of the conserved core domains of yeast TBP, TFIIA, TFIIB and TATA-box DNA has been assembled from purified components. Crystals of the complex were obtained by the hanging-drop vapor-diffusion method. Native data sets were collected at synchrotron sources. Crystal form I belongs to space group R32, with unit-cell parameters a = b = 173.2, c = 164.1 A, and diffracts to 2.5 resolution, but contains substoichiometric amounts of TFIIB. Crystal form II was assembled with a longer piece of DNA than that used for form I crystals and contains the complete quaternary complex. These crystals belong to space group P42(1)2, with unit-cell parameters a = b = 141.7, c = 112.0 A, and diffract to 3.6 A resolution.

Crystallization↗