Biomedical subjects

W C Lin

Publications and source records attributed to W C Lin.

At least 37 records · Page 2Linked to original sources

PubMed2001

Effect of CDA-II, urinary preparation, on lipofuscin, lipid peroxidation and antioxidant systems in young and middle-aged rat brain.

The levels of lipofuscin and lipid peroxidation reflect the degree of free radical-induced oxidative damage in the brain. We examined the effects of CDA-II, a preparation of human urine, on lipofuscin and lipid peroxidation in the brain of young (3.5 months) and middle-aged rats (17 months). The rats were given CDA-II orally at dosages of 0.3 or 1.0 g/kg daily for 8 weeks. CDA-II significantly suppressed the contents of lipofuscin and lipid peroxidation in both young and middle-aged rats. CDA-II also elevated the activity of superoxide dismutase, and the amounts of glutathione and ascorbic acid in the middle-aged rats, but not in the young ones. Our results suggest that the protection against oxidative damage by CDA-II in the young rat brain may be due to its scavenging activity against free radicals. In the middle-aged rats, in addition to the scavenging activity, the levels of endogenous antioxidants were also enhanced by the CDA-II treatment.

Animals↗

PubMed2001

Effects of (-)-menthol on arylamine N-acetyltransferase activity in human liver tumor cells.

To evaluate whether or not (-)-menthol affects arylamine N-acetyltransferase (NAT) activity, we selected human liver tumor cell line (J 5) for examination. By using high performance liquid chromatography, NAT activity for acetylation of 2-aminofluorene (AF) was determined. (-)-Menthol displayed a dose-dependent inhibition to cytosolic NAT activity. Time-course experiments showed that NAT activity measured from intact human liver tumor cells was inhibited by (-)-menthol for up to 24 hrs. But in human liver tumor intact cells, the low doses (0.0032 and 0.032 mM) of (-)-menthol promoted the NAT activity and the high doses (3.2 and 32 mM) of (-)-menthol inhibited NAT activity and the 0.32 mM (-)-menthol did not show any significant differences between control and (-)-menthol treated groups. Using standard steady-state kinetic analysis, it was demonstrated that (-)-menthol was a possible uncompetitive inhibitor (decrease Km and Vmax) to NAT activity in cytosols. This report is the first demonstration which showed (-)-menthol affect on human liver tumor cells NAT activity.

Antineoplastic Agents↗

PubMed2001

Increasing activity of H(2)-metabolizing microbes lowers decompression sickness risk in pigs during H(2) dives.

The risk of decompression sickness (DCS) was modulated by varying the biochemical activity used to eliminate some of the hydrogen (H(2)) stored in the tissues of pigs (19.4 +/- 0.2 kg) during hyperbaric exposures to H(2). Treated pigs (n = 16) received intestinal injections of Methanobrevibacter smithii, a microbe that metabolizes H(2) to water and CH(4). Surgical controls (n = 10) received intestinal injections of saline, and an additional control group (n = 10) was untreated. Pigs were placed in a chamber and compressed to 24 atm abs (20.6-22.9 atm H(2)). After 3 h, the pigs were decompressed and observed for symptoms of DCS for 1 h. Pigs with M. smithii had a significantly lower (P < 0.05) incidence of DCS (44%; 7/16) than all controls (80%; 16/20). The DCS risk decreased with increasing activity of microbes injected (logistic regression, P < 0.05). Thus the supplemental tissue washout of the diluent gas by microbial metabolism was inversely correlated with DCS risk in a dose-dependent manner in this pig model.

Animals↗

PubMed2001

The protective effects of PMC against chronic carbon tetrachloride-induced hepatotoxicity in vivo.

In this study, PMC (2,2,5,7,8-pentamethyl-6-hydroxychromane), a derivative of alpha-tocopherol, dose-dependently (1-10 mg/kg) ameliorated the increase in plasma aspartate aminotransferase (GOT) and alanine aminotransferase (GPT) levels caused by chronic repeated carbon tetrachloride (CCl4) intoxication in mice. Moreover, PMC significantly improved the CCl4-induced increase of hepatic glutathione peroxidase, reductase, and superoxide dismutase activities. PMC also restored the decrement in the glutathione content of hepatic tissues in CCl4-intoxicated mice. Furthermore, it also dose-dependently inhibited the formation of lipid peroxidative products during carbon tetrachloride treatment. Histopathological changes of hepatic lesions induced by carbon tetrachloride were significantly improved by treatment with PMC in a dose-dependent manner. These results suggest that PMC exerts effective protection in chronic chemical-induced hepatic injury in vivo.

Administration, Oral↗

PubMed2001

In vivo brain tumor demarcation using optical spectroscopy.

The applicability of optical spectroscopy for intraoperative detection of brain tumors/tumor margins was investigated in a pilot clinical trial consisting of 26 brain tumor patients. The results of this clinical trial suggest that brain tumors and infiltrating tumor margins (ITM) can be effectively separated from normal brain tissues in vivo using combined autofluorescence and diffuse-reflectance spectroscopy. A two-step empirical discrimination algorithm based on autofluorescence and diffuse reflectance at 460 and 625 nm was developed. This algorithm yields a sensitivity and specificity of 100 and 76%, respectively, in differentiating ITM from normal brain tissues. Blood contamination was found to be a major obstacle that attenuates the accuracy of brain tumor demarcation using optical spectroscopy. Overall, this study indicates that optical spectroscopy has the potential to guide brain tumor resection intraoperatively with high sensitivity.

Adult↗

PubMed2001

Interaction between 3-(p-tolylamino)-1,5-azulenequinone and the deoxyguanosine residue in various oligonucleotides upon photolysis.

Eight single-stranded oligodeoxyribonucleotides 32P-labeled at the 5'-end were synthesized; they were annealed with the complementary oligodeoxyribonucleotides to form the corresponding double-stranded helices. These duplexes possessed standard Watson-Crick base pairs, locally perturbed sites of a base mismatch, or a bulge. Further, 5'-32P-labeled oligodeoxyribonucleotides with a hairpin loop were also synthesized. Cleavage of these single- and double-stranded oligodexyribonucleotides selectively at the deoxyguanosine residue was accomplished by use of 3-(p-tolylamino)-1,5-azulenequinone 1 upon irradiation with 350 nm UV light. The single strands were cleaved more efficiently than the double-helices. For the helices containing a deoxyguanosine residue at a bulge, at a hairpin loop or toward the end, the cleaving efficiency was increased. Computation results indicate that two possibilities exist for agent 1 to form two "Watson-Crick type" hydrogen bonds with guanine in single-stranded oligodeoxyribonucleotides; yet, only one possibility exists in duplexes.

Base Sequence↗

PubMed2001

Sequential MR studies of a patient with white matter disease presenting psychotic symptoms: ADEM versus single-episode MS.

Acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS) are both demyelinating white matter disorders. It is difficult to differentiate ADEM from single episode MS because of the similar clinical presentation, cerebral spinal fluid (CSF) analysis, histological finding and magnetic resonance image (MRI) appearance. We report an ADEM case with unusual clinical presentations of predominant psychiatric symptoms, and relatively long disease course. Initially, we were not able to distinguish it from single episode MS. By means of sequential MR images followed up 2 years and spectroscopy studies, and the dramatic clinical improvement after corticosteroid therapy, ADEM was diagnosed as the disease entity of this patient. In this case report we will present the MR findings of this patient and discuss the differentiation between the ADEM and MS.

Adult↗

PubMed2001

Empirical monotherapy with meropenem in serious bacterial infections in children.

The efficacy and safety profile of meropenem were analyzed according to data collected from hospitalized pediatric patients aged 4 days to 20 years who had serious bacterial infections and were treated in a major teaching hospital in Taipei. Of the 53 patients enrolled, 47 were analyzed for clinical efficacy and 53 for safety. The satisfactory clinical response rate was 57% in lower respiratory tract infection, 58% in septicemia, 100% in complicated urinary tract infection, osteomyelitis, and central nervous system infection, 83% in skin and soft tissue infection, and 93% in intra-abdominal infection. Eleven (21%) patients experienced adverse events related to meropenem. The most commonly observed adverse reactions were elevated hepatic enzymes (7.5%), increased alkaline phosphatase (3.8%), and thrombocytosis (3.8%). There was no meropenem-related seizure, withdrawal, or death. The results of this study suggested that meropenem is well tolerated even in young infants, and is effective in treating serious childhood bacterial infection. However, this study also identified a proportion of hospitalized pediatric patients with isolates that were resistant to meropenem. The trends in meropenem resistance among nosocomially acquired bacteria should be monitored closely.

Adult↗

PubMed2000

Cardiac metastasis from a transitional cell carcinoma: a case report.

We report the case of a patient with a metastatic tumor in the right ventricle, apparently derived from a transitional cell carcinoma. The patient presented with severe hypoxemia as a result of right-to-left shunt due to the position of the tumor and a patent foramen ovale. The clinical course of this case is presented and the pathophysiology of the physiological effects caused by the metastatic tumor is discussed. The literature concerning cardiac metastases is reviewed.

Aged↗

PubMed2000

Integration of computer-assembled digital images and text data as evidence for the oncological record.

Digitally created visual images of pertinent patient data have been integrated with text information to formulate a visual evaluation and summary sheet (VESS) using computer processing. The VESS incorporates images of a patient's physical appearance, radiological images, pharmacokinetic graphs, and text information into a 1-page document of the patient's condition. Thus, computer processing of digital images and other information helps to refine patient data presentation, analysis, interpretation, and communication. This form of data management is especially valuable in oncological research, where clinical trials demand rapid, ongoing assessment of results and analysis of large amounts of data. The VESS is an effective mechanism for monitoring both the progress of individual patients and the endpoints of the overall clinical trial.

Diagnostic Imaging↗

PubMed2000

Phase II study of tamoxifen, ifosfamide, epirubicin and cisplatin combination chemotherapy in patients with non-small cell lung cancer failing previous chemotherapy.

We conducted a phase II study of tamoxifen, ifosfamide, epirubicin, and cisplatin (TIEP) chemotherapy in patients with non-small cell lung cancer (NSCLC) who had failed previous chemotherapy, in order to assess the response and toxicity of TIEP. Between November 1997 and May 1999, 25 patients were treated. Twelve of the 25 patients (48%) had been previously treated with cisplatin-based combination chemotherapy. TIEP doses were tamoxifen 60 mg oral twice daily on days 1-3; ifosfamide 2.4 g/m(2) intravenous infusion (IV) 60 min with mesna on day 2; epirubicin 40 mg/m(2) IV bolus on day 2; and cisplatin 50 mg/m(2) IV 60 min on day 2 every 4 weeks for up to six cycles. Seventy one cycles were given to 25 patients, with a median of three cycles (range one to six cycles). All patients were evaluable for toxicity profile and response rate. As expected, the major toxicity was myelosuppression. Grade 3 or 4 neutropenia occurred in 15 patients (60%) during treatment, as well as in 31% of the total courses. Febrile neutropenia occurred in two patients. No toxic death occurred in this study. Grade 3 thrombocytopenia occurred in five patients with five cycles. Toxicities other than myelosuppression were few and mild in severity. After two cycles of treatment, five of 25 patients (20%) had a partial response (95% confidence interval 4.3-35.7%). Among 12 patients previously treated with cisplatin-based chemotherapy, three patients (25%) achieved a partial response. The median time to disease progression was 4.9 months and median survival was 7.7 months. The response rate and median survival were better than in our previous study of salvage chemotherapy with ifosfamide, 5-FU, and leucovorin; and with ifosfamide, epirubicin, 5-FU, and leucovorin. In conclusion, TIEP appears to be an active combination regimen with an acceptable toxicity profile in Chinese patients with NSCLC who have failed previous chemotherapy.

Adenocarcinoma↗

PubMed2000

Phase II study with gemcitabine, ifosfamide and cisplatin in advanced non-small cell lung cancer.

The aim of the present study was to determine the clinical activity and toxicity of a novel chemotherapy combination regimen of gemcitabine, ifosfamide and cisplatin (GIP), administered every 3 weeks, in patients with inoperable non-small cell lung cancer (NSCLC). From October 1998 to July 1999, 18 previously untreated stages IIIb (4) and IV (14) patients were enrolled into the study. Gemcitabine and ifosfamide (with mesna as uroprotection) was administered on days 1 and 6, at a dose of 1000 and 1500 mg/m2, respectively; and cisplatin was given on day 1 at a dose of 60 mg/m2, every 3 weeks. All 18 patients were evaluable for response and toxicity profiles. One patient achieved a complete response, and II patients achieved a partial response, with an overall response rate of 66.7% (95%, CI, 45-89%). The main toxicity was hematological, a NCI grade 3-4 neutropenia in 16 patients (88.9%) during the treatment course. Febrile neutropenia occurred in three patients (16.6%). Grade 3 anemia occurred in eight patients (44.41%) and grade 3-4 thrombocytopenia occurred in 11 patients (61.1%). Non-hematological toxicity was mild and tolerable. No toxic death occurred. The median survival was 12.7 months and 1 year survival was 58.4%. The GIP combination chemotherapy produced a high response rate in advanced NSCLC; however, there was a relatively high percentage of hematological toxicity that still could be tolerated. A randomized trial comparing GIP to a two-drug combination of gemcitabine and cisplatin is planned.

Adult↗

PubMed2000

A phase II trial of tamoxifen, ifosfamide, epirubicin, and cisplatin combination chemotherapy for inoperable non-small-cell lung cancer.

A phase II trial of tamoxifen, ifosfamide, epirubicin, and cisplatin (TIEP) chemotherapy was conducted in patients with chemonaive inoperable non-small-cell lung cancer (NSCLC) to assess response and toxicity. From October 1997 to August 1998, 19 patients were treated. The treatment schema included tamoxifen 60 mg twice daily by mouth on days 1 to 3, ifosfamide 3 g/m2 intravenous infusion (IV) 60 minutes with mesna on day 2, epirubicin 50 mg/m2 IV bolus on day 2, and cisplatin 60 mg/m2 IV 60 minutes on day 2 every 4 weeks for up to six cycles. All patients were evaluable for response and toxicity. The major toxicity was myelosuppression; grade 3 or 4 leukopenia or neutropenia occurred in 14 of 19 (73.7%) patients during treatment, and 6 patients (31.6%) experienced fever in association with the neutropenia; no toxic deaths occurred. Grade 3 anemia occurred in six patients (31.6%) during the treatment. Grade 3 or 4 nausea/vomiting occurred in only one patient. Toxicities other than neutropenia and anemia were minimal. After two cycles of treatment, 9 of 19 patients attained a partial response (47.4%, 95% confidence interval 24.9%-69.9%) in this study. The median time to disease progression was 6 months and median survival time was 12 months. We conclude that TIEP is an active combination regimen with an acceptable toxicity profile in Chinese patients with inoperable NSCLC.

Aged↗

PubMed2000

Studies of detrusor-sphincter synergia and dyssynergia during micturition in rats via fractional Brownian motion.

In normal humans, the bladder is supposed to empty by a synergistic contraction of the detrusor and relaxation of the sphincter during micturition. By contrast, suprasacral spinal cord injury (SCI) patients usually will have both of them contract simultaneously and result in the so-called detrusor-sphincter dyssynergia. In this study, the cystometrograms of the detrusor and the electromyograms of external urethral sphincter of intact and SCI female Wistar rats are used to investigate the detrusor-sphincter synergia and dyssynergia during micturition. Due to the statistical self-similarity of the waveforms, the cystometrogram is modeled as discrete-time fractional Brownian motion and the electromyogram as discrete-time fractional Gaussian noise. Fractal dimensions of both of them are calculated and used as indices in the investigation of synergia. Results indicate that, for intact rats, the sphincter muscle is not only active but also recruited in a synchronous fashion with the detrusor. Furthermore, clear-cut measure using the fractal dimensions can be used to diagnose detrusor-sphincter synergia and dyssynergia.

Algorithms↗

PubMed2000

Brain tumor demarcation using optical spectroscopy; an in vitro study.

Optical spectroscopy for brain tumor demarcation was investigated in this study. Fluorescence and diffuse reflectance spectra were measured from normal and tumorous human brain tissues in vitro. A fluorescence peak was consistently observed around 460 nm (+/- 10 nm) emission from both normal and tumorous brain tissues using 337 nm excitation. Intensity of this fluorescence peak (F460) from normal brain tissues was greater than that from primary brain tumorous tissues. In addition, diffuse reflectance (Rd) between 650 and 800 nm from white matter was significantly stronger than that from primary and secondary brain tumors. A good separation between gray matter and brain tumors was found using the ratio of F460 and Rd at 460 nm (Rd460). Two empirical discrimination algorithms based on F460, Rd625, and F460/Rd460 were developed. These algorithms yielded an average sensitivity and specificity of 96% and 93%, respectively.

Algorithms↗

PubMed2000

Effects of berberine on arylamine N-acetyltransferase activity and 2-aminofluorene-DNA adduct formation in human leukemia cells.

Berberine is an alkaloid occurring in the plant genera Berberis and Coptis. Although berberine had been demonstrated to have antineoplastic function by inhibiting DNA-synthesis in activated lymphocytes, there is no available information to address berberine affects on human leukemia cell N-acetyltransferase (NAT) activity and 2-aminofluorene (AF)-DNA adduct formation. Thus, berberine was tested for inhibition of arylamine NAT activity and AF-DNA adduct formation in human leukemia cells. The NAT activity was measured by a high performance liquid chromatography assaying for the amounts of N-acetyl-2-aminofluorene (AAF) and N-acetyl-p-aminobenzoic acid (N-Ac-PABA) and the remaining AF and p-aminobenzoic acid (PABA). The NAT activity and AF-DNA adduct formation in human leukemia cells were inhibited by berberine in a dose-dependent manner, i.e. the higher the concentration of berberine, the higher the inhibition of NAT activity and AF-DNA adduct. The data also indicate that berberine decreased the apparent values of Km and Vmax from human leukemia cells in both cytosol and intact cells.

Antineoplastic Agents↗

PubMed2000

Scavenging of reactive oxygen species by a urinary preparation.

In the present paper, the antioxidant properties of a preparation of human urine (PHU) were evaluated by studying the ability of this drug to react with relevant biological oxidants such as superoxide anion radical (O2*-) and hydroxyl radical (OH*). In addition, its effect on lipid peroxidation was investigated in vitro and ex vivo. PHU is not a good scavenger of O2*-. However, it reacts rapidly with OH radicals with a second-order rate constant of 2.8 x 10(9)/M/sec. The studies on rat brain homogenates showed that PHU had an inhibitory effect, which was dependent on its concentration and the magnitude of lipid peroxidation. Ex vivo studies also showed that oral administration of PHU increased the antioxidant capacity of plasma from rats. The ability of PHU to scavenge free radicals suggests that this drug may be potentially useful in counteracting free radical-mediated diseases.

Animals↗

PubMed2000

Prognostic value of p53 expression in stage IB1 cervical carcinoma.

The purpose of this retrospective study was to evaluate the patterns of p53 expression in stage IB1 squamous cell carcinoma of the uterine cervix, to compare p53 expression with clinicopathological findings, and to assess its prognostic value. 27 patients with stage IB1 squamous cell carcinoma of the uterine cervix underwent abdominal radical hysterectomy and pelvic lymph node dissection. Expression of p53 was studied immunohistochemically. Overexpression of p53 was detected in 33.3% of the tumors, low expression was seen in 11.1%, and negative expression was found in 55.6%. Deep cervical stromal invasion (> or = 1/2) was found to be associated with the increased risk of lymph node metastases (odds ratio = 17.5). A significantly lower percentage of patients survived when p53 overexpression was observed (p = 0.0315). Univariate analysis revealed that tumor size (2-3.9 cm), lymph node metastasis, tumor invasion into parametria, tumor invasion into blood/lymph vessels, squamous cell carcinoma antigen (> or = 2 ng/ml), and p53 overexpression had a significantly lower recurrence-free survival rate. None of these above factors obtained significance in the multivariate analysis. This study suggests that expression of p53 may be indicative of an unfavorable prognosis in patients with stage IB1 squamous cell carcinoma of the uterine cervix.

Adult↗