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Biomedical subjects

C C Wang

Publications and source records attributed to C C Wang.

At least 37 records · Page 2Linked to original sources
PubMed2003

Using filtrate of waste biosolids to effectively produce bio-hydrogen by anaerobic fermentation.

Waste biosolids collected from sewage works is a biomass containing a vast amount of polysaccharides and proteins, and thus is considered a potential substrate for producing hydrogen using anaerobic fermentation. This work demonstrated, contrary to the common assumption, that the solids phase in waste activated biosolids presents extra nutrients for anaerobes; it in fact prohibits effective bio-hydrogen production. Using filtrate after removal of solids from biosolids produces more hydrogen than using the whole biosolids, with the former reaching a level an order of magnitude higher than the literature results.

Bacteria, Anaerobic↗
PubMed2003

Hydrogen production from wastewater sludge using a Clostridium strain.

Limited data in literature revealed a relatively low hydrogen yield from wastewater sludge, ca. 0.16 mg/g-dried solids, using anaerobic fermentation. We demonstrated in this work a much higher hydrogen yield, around 1.1 mg-H2/g-dried solids using a clostridium strain isolated from the sludge sample. The formed hydrogen would be consumed after passing the peak value at around 30-36 h of fermentation. We examined the effects of employing five different pre-treatments on substrate sludge, but noted no appreciable enhancement in hydrogen yield as commonly expected for methane production. Since a vast amount of organic matters had been released to water after hydrogen fermentation, we externally dosed methanogenic bacteria to the fermented liquor to produce methane. The fermented liquor could produce more methane than the non-fermented sample, indicating that the dosed methanogenic bacteria readily utilized the organic matters derived from the fermentation test.

Bioelectric Energy Sources↗
PubMed2003

In vitro susceptibility of six fluoroquinolones against invasive Streptococcus pneumoniae isolated from 1996 to 2001 in Taiwan.

A total of 331 invasive nonduplicated Streptococcus pneumoniae isolates from three sampling periods during 1996 to 2001 were tested for susceptibility to recently developed fluoroquinolones. Five major serotypes, 23F, 6B, 14, 19F, and 3, were frequently encountered in this collection. Penicillin nonsusceptible isolates constituted 52.9% from 1996 to 1997, 61.6% from 1998 to 1999, and 60.0% from 2000 to 2001. Fifty-seven percent of the isolates were susceptible to cefotaxime, 56.5% to ceftriaxone, 54.1% to cefepime, and 52.6% to cefuroxime. Macrolide-susceptible isolates constituted less than 14% of the total sample, and no vancomycin-resistant isolates were detected. For fluoroquinolones, MIC90 was lowest for gemifloxacin (MIC90 = < or = 0.12 microg/ml), followed by moxifloxacin (MIC90 = 0.25 microg/ml), gatifloxacin (MIC90 = 0.5 microg/ml), sparfloxacin (MIC90 = 0.5 microg/ml), levofloxacin (MIC90 = 1 microg/ml), and ciprofloxacin (MIC90 = 2 microg/ml). All isolates were susceptible to sparfloxacin, levofloxacin, gatifloxacin, and gemifloxacin apart from one isolate (0.3%), which was simultaneously resistant to sparfloxacin, levofloxacin, and gatifloxacin. Mutations at the positions S81F of GyrA and D435N and I460V of ParC were detected for this multiple drug resistant isolate. The in vitro results suggest that recently developed fluoroquinolones are very effective against invasive S. pneumoniae isolates in Taiwan. Nevertheless, emerging fluoroquinolone resistance should be acknowledged and clinicians alerted. Surveillance should be carried out to monitor any changes in antibiotic resistance of S. pneumoniae.

Adult↗
PubMed2003

Lymphoma of the nasal cavity and paranasal sinuses: treatment and outcome of early-stage disease.

The records of 23 patients diagnosed and treated at the Massachusetts General Hospital for extranodal non-Hodgkin's lymphoma of the paranasal sinus and nasal cavity were reviewed. The majority of patients were Ann Arbor stage I and approximately evenly divided in T1 or T2 (n = 10) and T3 or T4 (n = 13). Eight patients had nasal-type NK/T cell and 15 patients had diffuse large B-cell lymphoma (DLBCL). The patients with nasal-type NK/T cell lymphoma predominately involved the nasal cavity (5/8), whereas the DLBCL more often had the paranasal sinuses as the primary site (12/15). All patients received radiation as part of their treatment. Only three patients received chemotherapy as part of their initial treatment for three cycles using a cyclophosphamide, doxorubicin, vincristine, and prednisone-based regimen. By coincidence, the estimated overall survival (OS) and disease-free survival rates for both 5 and 10 years were all the same for all analyses. The OS for the entire group at 10 years was 78%. Significant prognostic factors were Ann Arbor stage IEA versus IIEA ( p = 0.0001) and T stage with (T1 or T2) versus (T3 or T4) (p = 0.0243). Combining Ann Arbor stage and T stage created a highly significant prognostic variable (IEA & [T1 or T2], IEA & [T3 or T4], IIEA & [T1 or T2], IIEA & [T3 or T4]) at p = 0.0001, regardless of site or histology. Patients with local-regional disease appear to be well controlled with radiation alone, but distant failure remains a problem. A combined-modality approach with local-regional radiation and systemic chemotherapy is recommended for these patients.

Adult↗
PubMed2003

Combined Fenton-MF process increases acrylonitrile removal.

The Fenton oxidation process is possessed of the advantages of both oxidation and coagulation processes. In addition to these functions, Fenton's reagent is also a typical initiator of polymerization. The application of the Fenton-microfiltration process for removal of acrylonitrile (AN), which is the major raw material for manufacturing ABS reins, was investigated. As for Fenton oxidation, in the range of pH 2 to pH 4, AN removal efficiency increased as the pH increased. In experiment of the same initial molar ratio of [FeSO4]0/[H2O2]0, the higher dosage can obtain the higher removal efficiency. At pH 4, the AN removal increased as the [H2O2]0 increased for each [FeSO4]0. Acrylic acid and acrylamide were detected in the solution after Fenton oxidation. On the other hand, acrylamide, polyacrylamide, and polyacrylic acid exist in the precipitate after the Fenton oxidation of AN solution. Moreover, it was also found that the operational mode is an important factor of the combined Fenton-MF process.

Acrylonitrile↗
PubMed2002

Prognostic value of Chinese race in nasopharyngeal cancer.

PURPOSE: Nasopharyngeal carcinoma is rare in the United States and common in southern China. Evaluating American patients treated using a uniform technique and staged with CT scanning, we determined whether Chinese and non-Chinese patients differ in presentation and outcome. METHODS AND MATERIALS: Between 1979 and 1996, 172 patients treated at Massachusetts General Hospital received primary radiotherapy with curative intent for nasopharyngeal carcinoma. Forty-one patients (24%) were of Chinese descent, and 41% of cancers were classified as having lymphoepithelioma histologic features. Most patients received twice-daily radiotherapy and a brachytherapy boost, receiving a median dose of 72 Gy to the nasopharynx. RESULTS: At the initial presentation, the Chinese patients were significantly younger, less likely to smoke, more likely to have Stage IV disease, and more likely to have cancer with lymphoepithelioma histologic features. After controlling for stage, age, histologic type, and treatment variables, Chinese patients were significantly more likely to develop distant metastases (p <0.05). Although Chinese race does not predict for local control or overall survival, a younger age, continued tobacco use, total radiation dose, and lymphoepithelioma histologic features do. CONCLUSION: In a large retrospective analysis of nasopharyngeal carcinoma, Chinese and non-Chinese patients differed significantly in presentation-age, stage, and histologic features-and outcome. We suggest as an explanation differences in intrinsic tumor biology rather than differences in treatment techniques or staging systems. Additional trials in endemic countries are needed to confirm the optimal treatment of Chinese and Chinese-American patients.

Adult↗
PubMed2002

Cervical intraepithelial neoplasia is associated with increased polyamine oxidase and diamine oxidase concentrations in cervical mucus.

OBJECTIVE: The aim of this study was to establish whether reactive oxygen species, generated during oxidation of amines, catalyzed by polyamine oxidase (PAO) and diamine oxidase (DAO) in cervical secretions may play a role in the etiology of cervical cancer. METHODS: Cervical mucus was obtained from women attending the gynecological outpatient department: 139 with and 154 without cytological evidence of cervical intraepithelial neoplasia were recruited. The mucus was freeze dried in liquid nitrogen, weighed, and later resuspended for assay of PAO and DAO concentrations using a chemiluminescence method. The two groups were compared by group sequential analysis using PEST3 software. RESULTS: Patients with a colposcopic diagnosis of a high-grade squamous intraepithelial lesion (SIL) had significantly higher enzyme activities than control cases (L(N)PAO 1.37 (0.37) versus 1.18 (0.35): Student t test: P < 0.001; L(N)DAO 1.37 (0.36) versus 1.15 (0.37): Student t test: P < 0.001). CONCLUSION: It is probable that this rise in enzyme activity precedes cytological changes and plays some part in the etiology of cervical cancer, as the cells that undergo premalignant change are normally squamous in origin, whereas mucus is a product of columnar epithelium. Higher enzyme activity in patients with SIL than in controls may be a reflection of higher risk of exposure to amine substrates in semen through multiple sexual partners.

Amine Oxidase (Copper-Containing)↗
PubMed2002

Effects of high inspired oxygen fraction during elective caesarean section under spinal anaesthesia on maternal and fetal oxygenation and lipid peroxidation.

BACKGROUND: Oxygen supplementation is given routinely to parturients undergoing Caesarean section under regional anaesthesia. While the aim is to improve fetal oxygenation, inspiring a high oxygen fraction (FIO2) can also increase free radical activity and lipid peroxidation in both the mother and baby. In this prospective, randomized, double-blind study, we investigated the effect of high inspired oxygen fraction (FIO2) on maternal and fetal oxygenation and oxygen free radical activity in parturients having Caesarean section under spinal anaesthesia. METHODS: Forty-four healthy parturients were randomized to breathe either 21% (air group) or 60% oxygen (oxygen group) intraoperatively via a ventimask. Maternal arterial blood was collected at 5-min intervals from baseline until delivery, and umbilical arterial and venous blood was collected at delivery. We measured blood gases and the products of lipid peroxidation (8-isoprostane, malondialdehyde (MDA), hydroperoxide (OHP)) and purine metabolites. RESULTS: At delivery, the oxygen group had greater maternal arterial PO2 [mean 30.0 (SD 6.3) vs 14.2 (1.9) kPa; mean difference 15.8 kPa, 95% confidence interval 12.9-18.7 kPa, P<0.001] and greater umbilical venous PO2 [4.8 (1.0) vs 4.0 (1.4) kPa; mean difference 0.8 kPa, 95% confidence interval 0.0-1.5 kPa, P=0.04] compared with the air group. Maternal and umbilical plasma concentrations of lipid peroxides (8-isoprostane, MDA, OHP) were greater in the oxygen group than in the air group (P<0.05). CONCLUSIONS: We conclude that breathing high FIO2 modestly increased fetal oxygenation but caused a concomitant increase in oxygen free radical activity in both mother and fetus.

Adult↗
PubMed2002

Role of neck surgery in conjunction with radiation in regional control of node-positive cancer of the oropharynx.

For patients with clinically node-positive oropharynx cancer treated with radiotherapy, planned neck dissection is controversial. We investigated whether neck surgery after radiation reduces nodal recurrence. Between 1970 and 1995, 263 patients at Massachusetts General Hospital received radiotherapy for clinically node-positive base of tongue or tonsil carcinomas. Patients received three different types of treatment: neck surgery followed by radiation (SR)-50 patients; radiation alone (RT)-160 patients; and radiation followed by surgery (RS)-53 patients. Median patient follow-up was 28 months. SR patients have an 84% complete response (CR) rate, RT patients 76%, and RS patients 13%. In multivariate analysis, among patients with a CR, the three treatment groups have the same regional control rates. Among patients with an incomplete response, the RS treatment group is 67% (p < 0.01) and 86% (p < 0.01) less likely to have recurrence than the RT and SR groups, respectively. Neck dissection after radiation therapy improves regional control for patients without a complete clinical response to radiation therapy but not for those with a CR. Despite higher CR rates, neck dissection before radiation confers no regional control benefit. We therefore recommend that primary radiotherapy with neck dissection be reserved for those without a complete clinical response.

Adult↗
PubMed2002

The relationship between slow and sharp waves (spikes) and also clinical seizures.

This study investigated the relationship between slow waves and sharp waves (spikes) and also clinical seizures in 255 patients with 694 EEGs over a 25-yr period. Slow waves were quantified into five groups, sharp waves into three groups and clinical seizures also into three groups. In general, as clinical seizures increased, the number of patients with many discharges increased and the number with only rare discharges decreased. Also, as patients became seizure free, there was a decreasing incidence of many sharp waves and an increasing incidence of only rare sharp waves. No relationships could be found in patients with a typical number of discharges or a steady number of seizures. Thus, a relationship between sharp waves and seizures was found mainly when there were changes in these variables. For sharp and slow waves, rare discharges were most often associated with mild slowing, while many discharges were most often related to a marked degree of slow wave abnormality. The combination of slow and sharp waves together, compared with only one type of EEG abnormality, was associated with more clinical neurological symptoms, especially a mental status change. The EEG groups were divided into four types of findings of slow and sharp waves, appearing in at least a first and/or second record. The results from these four EEG groups allow for a prediction of the findings to be found in a second record, based on the results of the first EEG. In general, there was a relationship between more slow waves, more sharp waves and more seizures. Also minimal slowing and rare discharges on the first record tended to disappear in the next EEG.

Adolescent↗
PubMed2002

Byakangelicol, isolated from Angelica dahurica, inhibits both the activity and induction of cyclooxygenase-2 in human pulmonary epithelial cells.

We examined the inhibitory mechanism of byakangelicol, isolated from Angelica dahurica, on interleukin-1beta (IL-1beta)-induced cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) release in human pulmonary epithelial cell line (A549). Byakangelicol (10-50 microM) concentration-dependently attenuated IL-1beta-induced COX-2 expression and PGE2 release. The selective COX-2 inhibitor, NS-398 (0.01-1 microM), and byakangelicol (10-50 microM) both concentration-dependently inhibited the activity of the COX-2 enzyme. Byakangelicol, at a concentration up to 200 microM, did not affect the activity and expression of COX-1 enzyme. IL-1beta-induced p44/42 mitogen-activated protein kinase (MAPK) activation was inhibited by the MAPK/extracellular signal-regulated protein kinase (MEK) inhibitor, PD 98059 (30 microM), while byakangelicol (50 microM) had no effect. Treatment of cells with byakangelicol (50 microM) or pyrrolidine dithiocarbamate (PDTC; 50 microM) partially inhibited IL-1beta-induced degradation of IkappaB-alpha in the cytosol, translocation of p65 NF-kappaB from the cytosol to the nucleus and the NF-kappaB-specific DNA-protein complex formation. Taken together, we have demonstrated that byakangelicol inhibits IL-1beta-induced PGE2 release in A549 cells; this inhibition may be mediated by suppression of COX-2 expression and the activity of COX-2 enzyme. The inhibitory mechanism of byakangelicol on IL-1beta-induced COX-2 expression may be, at least in part, through suppression of NF-kappaB activity. Therefore, byakangelicol may have therapeutic potential as an anti-inflammatory drug on airway inflammation.

Cell Survival↗
PubMed2001

Cross [2 + 2] cycloaddition of bicyclic alkenes with alkynes mediated by cobalt complexes: a facile synthesis of cyclobutene derivatives.

Bicyclic alkenes 1a-e and 5 undergo [2 + 2] cycloaddition with a variety of alkynes PhC(triple bond)CPh, (TMS)C(triple bond)CH, HC(triple bond)C(CH(3))(2)OH, (TMS)C(triple bond)CCO(2)Et, PhC(triple bond)CCH(3), C(2)H(5)C(triple bond)CC(2)H(5), CH(3)C(triple bond)CC(3)H(7), and CH(3)C(triple bond)CC(2)H(5) in the presence of Co(PPh(3))(2)I(2), PPh(3), and Zn powder in toluene to afford the corresponding exo-cyclobutene derivatives 3a-m, 6, and 8a-g in fair to excellent yields. The yield of this cycloaddition is highly sensitive to the cobalt catalyst, solvent, ligand, and temperature used. A mechanism involving a metallacyclopentene intermediate is proposed to account for this cobalt-catalyzed cyclization.

Journal Article↗
PubMed2001

Zinc fingers and thiol-disulfide oxidoreductase activities of chaperone DnaJ.

Chaperone DnaJ is a homodimer with each subunit containing 10 cysteine residues and two Zn(II) ions, which have been identified to form two zinc fingers, C(144)DVC(147)Zn(II)C(197)NKC(200) (Zn1) and C(161)PTC(164)Zn(II)C(183)PHC(186) (Zn2), with C(265) and C(323) in reduced form. Guanidine hydrochloride at 6.4 M destroys only Zn1, which does not reform after refolding. p-Hydroxymercuriphenylsulfonate acid, but not ethylenediaminetetraacetic acid (EDTA) even at high concentrations, can remove two Zn(II) ions from DnaJ, but only Zn2 can be reconstituted. After removal of Zn(II) ions, only C(144) and C(147) in Zn1 are oxidation-resistant, and the other six cysteines are easily oxidizable. DnaJ shows reductase activity and oxidase activity but little, if any, isomerase activity. The reductase activity is reversibly inhibited by EDTA. Zn2 is important for the enzymatic activity, and only -C(183)PHC(186)- among the four motifs of -CXXC- functions as the active site of the enzyme. A C-terminal (Q(181)-R(376)) fragment shows a zinc finger of C(183)PHC(186)Zn(II)C(197)NKC(200) and full enzymatic activity of DnaJ. The N-terminal half sequence (M(1)-Q(180)) and Zn1 are not required for the enzymatic activity but are important for the chaperone activity of DnaJ.

Aprotinin↗
PubMed2001

Induction chemotherapy with mitomycin, epirubicin, cisplatin, fluorouracil, and leucovorin followed by radiotherapy in the treatment of locoregionally advanced nasopharyngeal carcinoma.

PURPOSE: Survival in advanced nasopharyngeal carcinoma (NPC) is compromised by distant metastasis. Because mitomycin is active against hypoxic and G0 cells, which may help to eradicate micrometastasis, we investigated the effect of mitomycin-containing cisplatin-based induction chemotherapy. PATIENTS AND METHODS: Recruited for this study were American Joint Committee on Cancer (AJCC) 1992 staging system stage IV NPC patients with the following adverse features: obvious intracranial invasion, supraclavicular or bilateral neck lymph node metastasis, large neck node (> 6 cm), or elevated serum lactate dehydrogenase (LDH) level. Patients were given three cycles of chemotherapy before radiotherapy. The chemotherapy comprised a 3-week cycle of mitomycin, epirubicin, and cisplatin on day 1 and fluorouracil and leucovorin on day 8 (MEPFL). RESULTS: From January 1994 to December 1997, 111 patients were recruited. The median follow-up period was 43 months. The actuarial 5-year overall survival rate was 70% (95% confidence interval [CI], 60% to 80%; n = 111). For patients having completed radiotherapy (n = 100), the 5-year locoregional control rate was 70% (95% CI, 55% to 84%) and the distant metastasis-free rate was 81% (95% CI, 73% to 89%). The 5-year distant metastasis-free rate of N3a and N3b disease of AJCC 1997 staging system were 79% (95% CI, 62% to 95%) and 74% (95% CI, 60% to 89%), respectively. By Cox multivariate analysis, high pretreatment serum LDH level (P = .04) and neck nodal enlargement before radiotherapy (P = .001) were adverse prognostic factors of survival. CONCLUSION: The good 5-year survival of N3 disease supports the effectiveness of induction MEPFL in the primary treatment of advanced NPC. Further investigation to incorporate concurrent chemoradiotherapy is warranted.

Adolescent↗