PubMed Health⌕ Search

Biomedical subjects

T C Huang

Publications and source records attributed to T C Huang.

At least 19 recordsLinked to original sources
PubMed2005

Phase II study of weekly vinorelbine and 24-h infusion of high-dose 5-fluorouracil plus leucovorin as first-line treatment of advanced breast cancer.

We prospectively investigated the efficacy and safety of combining weekly vinorelbine (VNB) with weekly 24-h infusion of high-dose 5-fluorouracil (5-FU) and leucovorin (LV) in the treatment of patients with advanced breast cancer (ABC). Vinorelbine 25 mg m(-2) 30-min intravenous infusion, and high-dose 5-FU 2600 mg m(-2) plus LV 300 mg m(-2) 24-h intravenous infusion (HDFL regimen) were given on days 1 and 8 every 3 weeks. Between June 1999 and April 2003, 40 patients with histologically confirmed recurrent or metastatic breast cancer were enrolled with a median age of 49 years (range: 36-68). A total of 25 patients had recurrent ABC, and 15 patients had primary metastatic diseases. The overall response rate for the intent-to-treat group was 70.0% (95% CI: 54-84%) with eight complete responses and 20 partial responses. All 40 patients were evaluated for survival and toxicities. Among a total of 316 cycles of VNB-HDFL given (average: 7.9: range: 4-14 cycles per patient), the main toxicity was Gr3/4 leucopenia and Gr3/4 neutropenia in 57 (18.0%) and 120 (38.0%) cycles, respectively. Gr1/2 infection and Gr1/2 stomatitis were noted in five (1.6%) and 59 (18.7%) cycles, respectively. None of the patients developed Gr3/4 stomatitis or Gr3/4 infection. Gr2/3 and Gr1 hand-foot syndrome was noted in two (5.0%) and 23 (57.5%) patients, respectively. Gr1 sensory neuropathy developed in three patients. The median time to progression was 8.0 months (range: 3-25.5 months), and the median overall survival was 25.0 months with a follow-up of 5.5 to 45+ months. This VNB-HDFL regimen is a highly active yet well-tolerated first-line treatment for ABC.

Adult↗
PubMed2001

Differential effects of c7E3 Fab on thrombus formation and rt-PA-Mediated thrombolysis under flow conditions.

Although the Fab fragment of the mouse-human chimeric anti-alphaIIbbeta3 (GP IIb/IIIa) monoclonal antibody (MoAb) c7E3 facilitates recombinant tissue-type plasminogen activator (rt-PA)-mediated thrombolysis, it is not clear whether this is due to inhibition of new clot formation and/or a direct effect on the lysis rate. We employed an in vitro flow (re)circulation model to investigate how c7E3 Fab affected (a) platelet adhesion to clotted fibrin substrates under laminar flow at wall shear rates of 100 or 500 s(-1) and (b) rt-PA-induced lysis of preformed mural platelet-fibrin substrates at 500 s(-1). c7E3 Fab dose-dependently (0.5-5 microg/ml) inhibited platelet adhesion from flowing whole blood onto fibrin substrates ( approximately 14 microm thick) at each wall shear rate. When at 5 min after the onset of flow, c7E3 Fab (0.1-10 microg/ml) and rt-PA (1 microg/ml) were coinjected in flowing blood, it was found that modest fibrinolysis caused major platelet release from fibrin substrates and there was no difference in the lysis rate in the presence of rt-PA + c7E3 Fab compared to rt-PA alone. Platelet pretreatment with c7E3 Fab (10 microg/ml) had no effect on the lysis rate of thin ( approximately 40 microm), and slightly delayed the lysis rate of thick (< 250 microm), platelet-fibrin substrates containing evenly dispersed platelets (10(9)/ml). When the platelets within thick platelet-fibrin substrates were organized in platelet-rich regions ("residual thrombi"), these substrates followed a nonuniform lysis pattern, where fibrin between the thrombi lysed first and the residual thrombi lysed at a slower rate. Platelet pretreatment with c7E3 Fab (10 microg/ml) abolished the formation of the lytic-resistant residual thrombi and the associated platelet-protected fibrin zones. Hence, treatment with c7E3 Fab has no direct effect on the rate of rt-PA-mediated lysis, but is expected to block platelet-fibrin interactions that lead to clot retraction, thus maintaining a fibrin architecture that is more susceptible to lysis.

Abciximab↗
PubMed2001

Quantitative analysis of end-tidal carbon dioxide during mechanical and spontaneous ventilation in infants and young children.

Capnography provides a substitute for monitoring of arterial carbon dioxide tension (PCO(2)). We performed a prospective study to evaluate a new application of capnography, using quantitative curve analysis in the pediatric ICU. Twenty-five infants and children admitted to the pediatric ICU after cardiovascular surgery for congenital heart diseases were included in the study. Capnographic curves were recorded during 3 phases of mechanical and spontaneous ventilation: phase 1, immediate postoperative period; phase 3, preextubation period; and phase 2, period between phases 1 and 3. Each recording included 17 sec of capnographic tracings from consecutive spontaneous and/or ventilator-driven breaths. Quantitative curve analysis was made to define parameters including peak value of exhaled PCO(2) (P), mean rate of rise of PCO(2) (R), and area under each capnographic curve (A). Qualitative inspection of the wave contour showed no obvious difference in phase 3 during spontaneous and mechanically assisted ventilator breaths. However, an obvious difference existed between spontaneous and mechanically assisted breaths in phase 2. For each parameter (P, R, and A), there was a significant difference in phases 2 and 3 from spontaneous breaths. However, there was no significant difference in phases 2 and 3 from ventilator-assisted breaths. We further calculated the ratio of parameters of spontaneous breaths (S) and ventilator-assisted breaths (V) in phase 2 and phase 3. The ratio of S/V for P, R, and A showed significant differences between phase 2 and phase 3. We conclude that quantitative analysis of exhaled end-tidal PCO(2) curves revealed significant changes of specific parameters during the transition from the ventilator-dependent state to the spontaneously breathing ventilator-independent state. This new approach provides a new way to estimate respiratory status in infants and children receiving ventilator therapy. Through quantitative capnographic curve analysis, if P, R, and A from spontaneous breaths approached those of ventilator-assisted breaths, patients have resumed reasonable pulmonary mechanics, and extubation may then be considered.

Capnography↗
PubMed2001

Effect of phosphate on stability of pyridoxal in the presence of lysine.

The stability of the biologically active compound vitamin B(6) in aqueous solution was investigated. Schiff base formation is the major reaction between the epsilon-amino group of lysine and the aldehyde group of both pyridoxal and pyridoxal phosphate. Model systems composed of equal molar concentrations of lysine with either pyridoxal or pyridoxal phosphate were used to study the effect of proton transfer on Schiff base formation. Pyridoxylidenelysine was found to be the major product in both lysine/pyridoxal and lysine/pyridoxal phosphate systems. Quantitation of residual pyridoxal and pyridoxal phosphate was conducted using an HPLC to evaluate the degradation of pyridoxal and pyridoxal phosphate. The results indicate both the free phosphate ion in the buffer system and the bound phosphate on pyridoxal phosphate can enhance the formation of the Schiff base. The phosphate group serves as both proton donor and acceptor, which catalyzes the Schiff base formation. The aldehyde group on pyridoxal phosphate was found to be much more reactive than that on pyridoxal. The bound phosphate group on pyridoxal phosphate, with proton donating and accepting groups in close proximity, can simultaneously donate and accept protons, thus enhancing Schiff base formation between the aldehyde group and the epsilon-amino group. The deterioration rate of pyridoxal phosphate was faster than that of pyridoxal in an aqueous system.

Drug Stability↗
PubMed2000

Late coil migration due to thrombolysis after successful implantation of a coil for persistent ductus arteriosus.

Transcatheter coil occlusion of persistent ductus arteriosus (PDA) is now a widely accepted treatment for PDA. However, late complication might occur due to thrombolytic treatment during the interventional period. We discuss a case with late coil migration due to thrombolysis after successful implantation of a coil. It should be emphasized that early thrombus formation is important for successful closure of PDA shunt using coil.

Ductus Arteriosus, Patent↗
PubMed2000

Chemistry and antioxidative factors in rosemary and sage.

Rosemary and sage are common spices used in food. In our recent search of cancer chemopreventive agents from spices, the alcohol extracts of rosemary and sage showed strong antumorigenic activities. Rosemary and sage extracts contain active antioxidative factors such as phenolic diterpenes, flavonoids and phenolic acids. Here we discuss chromatographic methods used to separate and purify compounds from these spices and MS and NMR spectrometry to identify the isolated compounds. Several new compounds isolated from sage were determined to be 6-O-caffeoyl-beta-D-fructofuranosyl-(2-->1)-beta-glucopyranoside, 1-O-caffeoyl-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside, 1-O-p-hydroxybenzoyl-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside, 1-O-(3-methyl-2,3,4-trihydroxybutyl)-6-O-feruloyl-beta-D-glucopyranoside, 4-hydroxyacetophenone 4-O-[5-O-(3,5-dimethoxy-4-hydroxybenzoyl)-beta-D-apiofrunosyl]-(1-->2)-beta-D-glucopyranoside and 1-O-[2-hydroxy-5-(2-hydroxyethyl)phenyl]-6-O-trans-caffeoyl-beta-D-glucopyranoside.

Antioxidants↗
PubMed2000

Identification of oxidation products of (-)-epigallocatechin gallate and (-)-epigallocatechin with H(2)O(2).

(-)-Epigallocatechin gallate (EGCG) and (-)-epigallocatechin (EGC) are two important antioxidants in tea. They also display some antitumor activities, and these activities are believed to be mainly due to their antioxidative effects. However, the specific mechanisms of antioxidant action of tea catechins remain unclear. In this study are isolated and identified two novel reaction products of EGCG and one product of EGC when they were reacted separately with H(2)O(2). These products are formed by the oxidation and decarboxylation of the A ring in the catechin molecule. This study provides unequivocal proof that the A ring of EGCG and EGC may also be an antioxidant site. This study also indicates an additional reaction pathway for the oxidation chemistry of tea catechins.

Antioxidants↗
PubMed2000

Management of complications of bacillus Calmette-Guérin immunotherapy in the treatment of bladder cancer.

OBJECTIVE: To evaluate the management strategies available for the complications associated with bacillus Calmette-Guerin (BCG) immunotherapy in the treatment of bladder cancer. DATA SOURCES: Clinical literature accessed through MEDLINE (January 1983-January 1999). Key search terms included bacillus Calmette-Guérin, BCG, and bladder cancer. DATA SYNTHESIS: BCG vaccine is a live-attenuated strain of Mycobacterium bovis; therefore, the risk for complications exists. An evaluation of treatment regimens was conducted, and the management strategies are presented. CONCLUSIONS: The complications associated with BCG immunotherapy range from local reactions to potentially fatal systemic reactions requiring long-term therapy. Therefore, healthcare practitioners need to be aware of the current treatment regimens available.

BCG Vaccine↗
PubMed1999

Acute disseminated histoplasmosis complicated with hypercalcaemia.

A case of acute progressive disseminated histoplasmosis complicated with hypercalcemia is reported and the literature is reviewed. This and the previously reported cases imply that physicians should have a higher index of suspicion for this infection and the probable underlying diseases resulting from impaired cellular-mediated immunity when encountering patients with hypercalcaemia.

Fatal Outcome↗
PubMed1999

Characterization of volatile compounds from the reaction of 3-hydroxy-2-butanone and ammonium sulfide model system.

The reactions between 3-hydroxy-2-butanone and ammoniun sulfide at 25, 50, 75, 100, 125, and 150 degrees C were studied. Four well-known flavor compounds, 2,4,5-trimethyloxazole, 2,4, 5-trimethyl-3-oxazoline, 2,4,5-trimethylthiazole, and 2,4, 5-trimethyl-3-thiazoline, were identified. Another four interesting intermediate compounds, 2-(1-hydroxyethyl)-2,4, 5-trimethyl-3-oxazoline, 2-(1-mercaptoethyl)-2,4, 5-trimethyl-3-oxazoline, 2-(1-hydroxyethyl)-2,4, 5-trimethyl-3-thiazoline, and 2-(1-mercaptoethyl)-2,4, 5-trimethyl-3-thiazoline, were also identified by GC-EIMS and GC-CIMS. All these intermediate compounds were formed at 25 degrees C. On the other hand, tetramethylpyrazine was the major product with a reaction temperature higher than 100 degrees C.

Acetoin↗
PubMed1999

Characterization of plasmids that encode streptomycin-resistance in bacterial epiphytes of apple.

Streptomycin resistance in strains of Pseudomonas syringae pv. papulans, Pantoea agglomerans and a yellow-pigmented, non-fluorescent Pseudomonas sp. (Py), isolated from apple orchards in New York and Washington states, is predominantly associated with strA-strB genes carried on conjugal plasmids (R plasmids). None of 128 resistant Erwinia amylovora strains from the eastern and western USA hybridized with a strA-strB probe, SMP3. Resistant Py strains transfered R plasmids to Ps. syringae pv. papulans and to Py in vitro at frequencies of 10(-1)-10(-2) per recipient cell whereas Ps. syringae pv. papulans transferred its plasmids at frequencies of 10(-2) to below detectable levels. Transfer of R plasmids to P. agglomerans was not detected and resistant P. agglomerans did not transfer their R plasmids to any recipients. R plasmids were found to be highly diverse as measured by DNA fingerprint analysis. Transfer-deficient transposon mutants of R plasmid pCPP519 were generated, and 3.9 kb EcoRI and 3.0 kb SmaI fragments that hybridized with a Tn5 probe were cloned and sequenced. The deduced amino acid sequences of the 3.9 kb fragment were similar to proteins involved in replication, nicking at oriT, and piliation in other bacteria.

Amino Acid Sequence↗
PubMed1999

Lemierre's syndrome caused by viridans streptococci: a case report.

A 53-year-old man had fever, chills, and a progressively enlarged mass over the left mandibular angle for one month. A chest radiograph showed two small nodules in the upper right lung field. A contrast-medium-enhanced head-and-neck computed tomograph revealed severe necrosis within the left lateral pharyngeal space and total obliteration of the left internal jugular vein. Viridans streptococci were identified in the blood culture and the debrided tissue culture 2 days post-admission. The presentations were characteristic of Lemierre's syndrome and were evident in this case, however, the causative agent was viridans streptococci and the host was much older than the others previously reported. The normal flora of the oropharynx could become a fatal bacterium when the intact mucosal barrier of the mouth is impaired, regardless of the patient's age.

Humans↗
PubMed1998

Fibrinolytic agents inhibit platelet adhesion onto collagen type I-coated surfaces at high blood flow conditions.

The effect of fibrinolytic agents on platelet adhesion onto insolubilized collagen type I was evaluated. Normal human whole blood samples were incubated with agents and perfused over collagen-coated surfaces in a parallel-plate flow chamber. Platelet adhesion and aggregation were analyzed by video microscopy and image processing. When blood was perfused at 1500/s, both streptokinase and urokinase, each at 500 U/ml, caused a significantly less normalized platelet deposition, compared with controls. At 480/s, platelet deposition was not different between controls and test samples. Inhibition of platelet deposition at high flow rates was partly due to inhibition of platelet adhesion. Both ristocetin- and ADP-induced platelet aggregation were inhibited in test samples. The agents caused proteolytic degradation of plasma fibrinogen, but no degradation of platelet glycoproteins Ib and IIb-IIIa (GPIb and GPIIb-IIIa) and of plasma von Willebrand factor in test samples prior to perfusion. Post-perfusion von Willebrand factor degradation was not found. Plasmin may cause functional changes to plasma proteins and/or platelet receptors, altering their adhesive properties under flow. At high shear, fibrinogen degradation products may interfere with GPIIb-IIIa binding to insolubilized von Willebrand factor, leading to decreased platelet adhesion. Inhibition of platelet adhesion by thrombolytic agents could help maintain vessel patency after recanalization in stenosed arteries. Publishers.

Adenosine Diphosphate↗
PubMed1996

Regulation and molecular structure of a circadian oscillating protein located in the cell membrane of the prokaryote Synechococcus RF-1.

When a light/light-adapted culture of Synechococcus RF-1 is exposed to a diurnal light/dark regimen, the synthesis of more than ten of its polypeptides is known to become entrained to a circadian oscillating pattern which persists for some time under free-running conditions. One of the circadian oscillating polypeptides, COP23, was found to be located in the cell membrane. The rate of COP23 synthesis is controlled at the transcription level. In addition to the protein synthesis rate, the content of COP23 also exhibited a circadian rhythm. Pulse labeling with [35S]methionine revealed that COP23 was relatively stable in an arrhythmic culture. However, the exposure of Synechococcus RF-1 to a light/dark regimen induced not only a circadian synthesis rhythm, but also a rapid degradation of COP23 protein at a defined period of time. The induction of rapid protein degradation was prevented by the presence of chloramphenicol. The gene encoding the COP23 polypeptide has been cloned and sequenced. The amino acid sequence derived from the open-reading frame revealed that a signal peptide (28 amino acids) does not appear to be part of the mature COP23. The mature COP23 does not have a membrane-associated segment, and it is suggested to be a peripheral molecule. With respect to their DNA base sequence and protein amino acid sequence, none of the proteins documented in the EMBL and PC/Gene data bases are significantly homologous with the COP23 molecule.

Amino Acid Sequence↗