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Biomedical subjects

C Chung

Publications and source records attributed to C Chung.

At least 73 records · Page 4Linked to original sources

Mediastinal liposarcoma with local recurrence: a case report.

Liposarcoma is a rare mediastinal tumor. The treatment of choice is surgical resection. However, recurrence is not uncommon. In this report, recurrence of liposarcoma with local extension to chest wall is described in a 70-year-old Chinese male who had liposarcoma located in the anterior mediastinum and underwent tumor resection 5 years before. Long-term follow-up is indicated in patients with mediastinal liposarcoma because there may be an interval of several years between resection and recurrence.

Aged↗

Paclitaxel plus carboplatin and concurrent radiation therapy for patients with locally advanced non-small cell lung cancer.

Previously untreated patients with stages IIIA or IIIB non-small cell lung cancer entered this phase II study to evaluate the activity and toxicity of combined paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) and carboplatin and concurrent radiation. Patients received paclitaxel 50 mg/m2/wk as a 1-hour infusion and carboplatin area under the concentration-time curve of 2/wk for 7 weeks with radiation to the primary tumor and regional lymph nodes (44 Gy) followed by a boost to the tumor (22 Gy). In addition, patients received two additional cycles of paclitaxel 200 mg/m2 and carboplatin (area under the concentration-time curve of 6) 3 weeks apart. From March 1995 to February 1996, 23 patients entered the study and their overall response rate (complete plus partial responses) was 82%. The major toxicity was esophagitis. Nine patients (45%) had experienced grades 3 or 4 esophagitis by the end of the 7-week concurrent phase. Seven of the nine patients recovered from the esophagitis within 2 weeks and received the additional two cycles of paclitaxel 200 mg/m2 and carboplatin (area under the concentration-time curve of 6). Only one patient (4%) had grade 4 pneumonitis; this patient also recovered within 2 weeks and received the final two doses of combined chemotherapy. Therapy with paclitaxel, carboplatin, and concurrent radiation is a promising treatment for patients with locally advanced non-small cell lung cancer; it has a high response rate and acceptable toxicity.

Adult↗

Cervical thymic cysts: CT appearance of two cases including a persistent thymopharyngeal duct cyst.

The differential diagnosis of cervical cysts in children includes common entities such as branchial cleft cysts, thyroglossal duct cysts, and cystic hygromas. Congenital thymic cysts are uncommon and often misdiagnosed as either branchial cleft cysts or cystic hygromas. However, they may have an appearance on CT that can be characteristic. The course of the descent of embryologic thymic tissue in the neck to the mediastinum indicates the potential site of deposition of an ectopic cervical thymic cyst. In a child, a cystic lesion that has an intimate relationship to the carotid sheath is likely to be a thymic cyst. Of the approximately 100 cases of vestigial cervical thymus or thymic cysts that have been reported in children, only 5 cases of a persistent thymopharyngeal duct cyst have been described [1-5]. In two of these five, the persistent thymopharyngeal duct cyst was demonstrated by CT [1,2]. We report one additional case of a cervical thymic cyst and one case of a persistent thymopharyngeal duct cyst both depicted by CT.

Child, Preschool↗

Lipiodol uptake and retention by human hepatoma cells.

Lipodol has important diagnostic and therapeutic uses in hepatoma. However, the mechanisms of its selective, prolonged retention in hepatoma cells is not well understood. Therefore, using oil-red O, light and electron microscopy and neutron activation analysis we have determined that HepG2 cells are characterized by lipiodol deposition and emulsification on the cell surface, action uptake of lipodol by endocytosis, and prolonged intracellular retention. These findings may have major clinical significance in the development of a new treatment for hepatoma patients.

Carcinoma, Hepatocellular↗

Alternating irradiation and chemotherapy in stage III A and B nonsmall cell lung cancer: report of a cancer and Leukemia Group B phase II study 8636.

PURPOSE: A pilot trial testing the feasibility of chemotherapy and radiotherapy was done in Stage III A and B nonsmall cell lung cancer. The schedule was designed to be consistent with the laboratory model of Looney and Hopkins. METHODS AND MATERIALS: Treatment began with thrice-per-day radiotherapy for 3 days (16.2 Gy/nine fractions), followed by chemotherapy (cis-platinum 100 mg/m2 day 10, and vinblastine 4 mg/m2 days 10 and 12). A second cycle started on day 22, a third on day 43, and a fourth on day 64. We treated three cohorts. The first cohort received three cycles of radiotherapy alone, (48.6 Gy). The second cohort received three completed cycles, and the third received three completed cycles and a fourth radiotherapy course (64.8 Gy). Patients were evaluated for toxicity, protocol compliance, response, and survival. RESULTS: The patients in the first cohort experienced no toxicity. Fifty-six percent (56%) of the patients treated in cohort 2 experienced severe or life-threatening myelosuppression as did 82% of those in cohort 3. Nonhematologic toxicity was not severe; one case of Grade 3 esophagitis, one of reversible adult respiratory distress syndrome, and one radiation pneumonitis. We closed the trial after accrual to the third cohort because of significant myelosuppression. CONCLUSION: This schedule is too myelosuppressive to be used without modification.

Aged↗

Analysis of elemental absorption and excretion in mice bearing malignant ascites.

Feces, kidney, and small intestine were sampled from the mice bearing malignant ascites at different stages of tumor growth to investigate the kinetics of elemental distribution in the body. The contents of 14 elements in samples were determined by instrumental neutron activation analysis (INAA). The elements Br, Cl, Cu, Na, Se, and Zn increased, whereas Mn and Rb decreased in kidney with the growth of the tumor. The elements Cl, Na, and Fe, however, appeared to have significantly different behavior in the small intestine.

Animals↗

Determination of whole-body nitrogen and radiation assessment using in vivo prompt gamma activation technique.

Body nitrogen content in the phantom is measured by semiconducting and scintillation spectrometers using in vivo prompt gamma-ray activation analysis technique. The effective dose rate equivalents for sensitive organs and tissues inside the phantom are assessed by dosimetric measurement and neutron transport calculation. The bismuth germanate scintillator is found superior to the germanium semiconducting detector to quantitatively measure the photopeak of the 10.829 MeV prompt gamma-ray emitted from the 14N(n, gamma) reaction. Recommended scanning period for current setup using the BGO detector is 1 h on the modified mobile nuclear reactor. The effective dose equivalents from both neutrons and gamma-rays are estimated around 63 microSv per scan in the phantom test, making it a safe and reliable nuclear analytical method for in vivo body nitrogen measurement.

Activation Analysis↗

A randomized controlled trial on the treatment for acute partial ischemic stroke with acupuncture.

The effectiveness of acupuncture in acute stroke remains largely untested and unproved. A randomized, controlled trial was carried out to study the feasibility of acupuncture in combination with conventional supportive treatment for acute stroke patients. A total of 30 patients, aged 46-74, with the onset of symptoms within 36 h were enrolled into the study after appropriate screening. All patients gave informed consent. Basing on the same supportive treatment, patients were randomly assigned to a treatment with or without acupuncture. The procedure and acupoint selection were discussed and decided through several meetings of a group of senior acupuncture doctors in Taiwan. Acupuncture was applied 3 times/week for 4 weeks. During the study period, there were no problems in conducting this trial in terms of patient availability and acceptance, and physician cooperation. A significantly better neurologic outcome was observed in the acupuncture group on day 28 and day 90. The improvement in neurologic status was greatest in patients with a poor neurologic score at baseline. There were no important side effects except for one episode of dizziness related to acupuncture treatment. The data and results of this study will be used as a guideline for planning a full-scale clinical trial, e.g. sample size calculation, method of randomization with stratification of prognostic factors, choosing acupuncture points and technique of acupuncture.

Acupuncture Points↗

Effect of etomoxiryl-CoA on different carnitine acyltransferases.

The effects of etomoxiryl-CoA on purified carnitine acyltransferases and on carnitine acyl-transferases of rat heart mitochondria and rat liver microsomes were determined. At nanomolar concentrations, the data agreed with that of other investigators who have shown that etomoxiryl-CoA must be binding to a high affinity site with specific inhibition of mitochondrial carnitine palmitoyltransferase (CPTo). Micromolar amounts of etomoxiryl-CoA inhibited both short- and long-chain carnitine acyltransferases. The concentrations of etomoxiryl-CoA required for 50% inhibition of the different carnitine acetyltransferases and microsomal and peroxisomal carnitine octanoyltransferase were in the low micromolar range. Mixed-type and uncompetitive inhibition kinetics were obtained, depending on the source of purified enzyme. When purified rat heart CPT was incubated with etomoxiryl-CoA, it increased the K0.5 and decreased the Hill coefficient for acyl-CoA. Both proteins and phospholipids of mitochondria and microsomes formed covalent adducts of [3H]etomoxir, with the predominant labeling in phospholipids. None of the purified enzymes formed covalent adducts when incubated with [3H]etomoxiryl-CoA, in contrast to intact mitochondria or microsomes. The major 3H-labeled protein for rat heart mitochondria had a molecular weight of 81,000 +/- 4000, and the major proteins from microsomes had a molecular weight of 51,000-57,000. Malonyl-CoA prevented most of the tritum incorporation into the 81,000 Da protein of mitochondria, but it had little effect on incorporation of tritiated etomoxir into the 51,000-57,000 Da proteins of microsomes. When 50 microM etomoxiryl-CoA was added to microsomes and to mitochondria that had been incubated with radioactive etomoxiryl-CoA, much of the radioactive etomoxir disappeared from the major microsomal proteins, but virtually none was displaced from the mitochondrial protein. Thus, at least two different types of covalent etomoxir complexes were formed. This pulse-chase experiment showed that the mitochondrial protein-etomoxir complex was not turned over, consistent with other data showing that etomoxir inhibited carnitine palmitoyltransferase. In contrast, the major protein-etomoxir complex in microsomes was turned over during the pulse-chase experiment.

Adenosine Triphosphate↗

Radionuclide monitoring in environmental water body using an in situ gamma probe.

An HPGe gamma probe designed to monitor radioactive nuclides in environmental water in situ is described. The probe is equipped with a 15% HPGe detector and an associated spectrum analyzer. Laboratory tests were performed to evaluate its operating depth, detecting sensitivity, detecting volume and the detection limits of radionuclides. A field operation was conducted to measure in situ radionuclide concentrations in a nuclear reactor pool, and the feasibility as well as the disadvantages of this rapid survey are discussed.

Environmental Monitoring↗

Acupuncture in the treatment of renal colic.

A prospective randomized study was performed to compare the effect of acupuncture and intramuscular Avafortan injection in the treatment of renal colic. Our results showed that acupuncture is as effective in relieving renal colic as Avafortan but it had a more rapid analgesic onset (3.14 +/- 2.88 minutes versus 15.44 +/- 7.55 minutes, p less than 0.05). Of the patients in the Avafortan group 7 (43.8%) had side effects, including skin rash in 3, tachycardia in 2, drowsiness in 1 and facial flush in 1. No side effects were noted in the acupuncture group. During 2 hours of observation acupuncture and Avafortan seemed to be ineffective in promoting stone passage. However, patients receiving Avafortan treatment were more likely to have paralytic ileus. In summary, acupuncture can be a good alternative for the treatment of renal colic.

Acupuncture Therapy↗

Serum interleukin-6 levels correlate with disease status in patients with epithelial ovarian cancer.

Interleukin-6 is a pleiotropic cytokine with a wide range of effects, including induction of B-cell and cytotoxic T-cell differentiation, and induction of acute phase reactant production by hepatocytes. Interleukin-6 also can act as an autocrine growth factor in malignancy. Various cell types produce interleukin-6, including T and B cells, monocytes, fibroblasts, and some solid tumor cells. In previous work we detected the production of substantial amounts of interleukin-6 by human ovarian cancer cells, including the ovarian cancer cell lines CAOV-3, OVCAR-3, and SKOV-3, and several primary ovarian tumor cultures. In this study we retrospectively examined 90 separate serum specimens for interleukin-6 in 36 patients with epithelial ovarian cancer. The mean serum interleukin-6 concentration of those ovarian cancer patients with macroscopic disease (n = 57) was 0.26 +/- 0.04 U/ml (mean +/- SEM). Healthy adult donors have interleukin-6 serum levels of 0.12 +/- 0.03 U/ml. Sixteen of 21 ovarian cancer patients with macroscopic disease (76%) had elevated (greater than 0.20 U/ml) levels of serum interleukin-6, with levels approaching 1 U/ml in some patients (p less than 0.01). Of those nine patients with bulky tumor (residual greater than 2 cm), eight (89%) had an elevated interleukin-6 level (mean, 0.31 +/- 0.05), while eight of 12 (66%) with minimal residual disease (less than 2 cm) had elevated levels. Only two of 15 (13%) patients who were in clinical remission and who had microscopic disease had elevated values. Of the 36 patients, 22 were CA 125 negative (less than 35 U/ml), and of these, four had elevated interleukin-6 levels. Of the 14 patients with an elevated CA 125 level, 12 (86%) had elevated interleukin-6 levels. In those 16 patients in whom serial levels of interleukin-6 were measured, rising levels were found over a 3 to 4 month interval in nine (56%); this correlated with tumor progression. Furthermore, the subsequent survival of patients was shown to correlate with the level of interleukin-6, such that patients whose levels were elevated greater than 0.20 U/ml interleukin-6 survived a mean of 12.5 months, compared with 27.2 months for patients with normal levels (p less than 0.001). These data support the concept that interleukin-6 may be a useful tumor marker in some patients with epithelial ovarian cancer, as it correlates with the tumor burden, clinical disease status, and survival.

Antigens, Tumor-Associated, Carbohydrate↗

Monoclonal antibodies to the cell surface and a soluble form of the human nerve growth factor receptor.

Monoclonal antibodies (designated IIIG5, VIID1, VIIIC8, and XIF1) have been produced that bind to the human nerve growth factor receptor (NGF-R) as well as to a soluble, truncated form of the receptor (NGF-Rt). The antibodies were generated against partially purified NGF-Rt from the conditioned medium of E9b cells, a transfected mouse fibroblast cell line (Ltk-) that expresses large numbers of the low affinity form of the human NGF-R on its cell surface (Chao MV, Bothwell MA, Ross AH, Koprowski H, Lanahan AA, Buck CR, Sehgal A [1986]: Science 232:518-521). Hybridomas were screened by radiometric immunosorbent assay (RISA) and by immunoprecipitation of solubilized cell surface receptor covalently cross-linked to [125-I]-NGF. Four positive lines were cloned by limiting dilution and were found to secrete monoclonal antibodies of the IgGl,k subclass. All monoclonal antibodies bound to both NGF-R and NGF-Rt. Two monoclonal antibodies (VIID1, XIF1) immunoblotted the NGF-R from E9b cell preparations resolved on non-reducing sodium dodecyl sulfate (SDS)-polyacrylamide gels. The antibodies immunoprecipitated NGF-R from both E9b cells and from SH-SY5Y human neuroblastoma cells. The monoclonal antibodies bound to monkey (rhesis and cynomolgus) NGF-Rt, but did not cross-react with NGF-R from chick or rat. Results of antibody competition studies demonstrated that three antibodies bound to a similar or overlapping epitope on the NGF-Rt and one monoclonal antibody (IIIG5) recognized a distinct receptor epitope. Antibodies that bound to different sites on the receptor were used to develop a sensitive 2-site RISA. The 2-site RISA can be used to rapidly quantitate NGF-R and NGF-Rt in large numbers of biological samples in the absence of added [125-I]-labeled NGF.

Antibodies, Monoclonal↗

Clinical study of syncope during acupuncture treatment.

From August 1988 to April 1989, we observed 52 patients who developed so-called 'needle fainting' (or what the Chinese call 'Yun-Cheng' phenomenon) 55 times among a total sample of 28,285 procedures of acupuncture therapy at the Center for Traditional Medicine of Veterans General Hospital in Taipei. Of these syncopal patients, 35 were male and 17 were female. Their mean age was 45 years (with a range of 11 to 72 years). All patients were in an upright position when needle fainting occurred. Their usual manifestations were pallor, cold sweating, nausea, and bradycardia. They all recovered soon after lying down; no one developed a complete loss of consciousness. No mortality was noted. When comparing the patients who experienced syncope during their first visit to our Clinic (Group I, n = 27) with the patients who experienced syncope in a follow-up treatment (Group II, n = 25; 3 patients had 2 episodes in sequential treatments), we found a significantly higher incidence of needle fainting (p less than 0.0001) in Group I patients (27 out of 2,855 or 0.94%) than in Group II patients (28 out of 25,430 or 0.11%). The mean age of Group I patients (39 +/- 15.4 years) was significantly less than that of Group II patients (51.6 +/- 18.0 years) (p less than 0.001). The coexistence of other medical problems was significantly higher in Group II patients (72%) than in Group I patients (18.5%) (p less than 0.0001).

Acupuncture Therapy↗

Subcutaneous injection of 99mTc pertechnetate at acupuncture points K-3 and B-60.

The acupuncture points are known to be morphologically related to the nerves and vessels. Yet the physiological role of blood vessels in the formation of acupuncture points remains unknown. With subcutaneous injection of 99mTc pertechnetate at the acupuncture points K-3 and B-60 and with intra-acupuncture point injection of 99mTc pertechnetate at K-3 and B-60, a lower-limb venography like what was obtained by intravenous injection of 99mTc macroaggregated albumin was demonstrated in the present study. It seems that some acupuncture points do play a role in drainage of tissue fluid from soft tissue into the veins.

Acupuncture Points↗

Preparation of an affinity chromatography matrix for the selective purification of the dopamine D2 receptor from bovine striatal membranes.

A ligand affinity matrix has been developed and utilized to purify the dopamine D2 receptor approx. 2100 fold from bovine striatal membranes. 3-[2-Aminoethyl]-8-[3-(4-fluorobenzoyl)propyl]-4-oxo-1-phenyl-1,3,8- triazaspiro[4.5]decan-4-one (AES) was synthesized and used to prepare the affinity matrix by coupling to epoxy-activated Sepharose 6B (AES-Sepharose). AES (Ki approximately 1.7 nM) is similar in potency to the parent compound, spiperone (Ki approximately 0.8 nM), in competing for [3H]spiperone-binding activity. AES has no significant potency in competing for the dopamine D1 receptor as assessed by competition for [3H]SCH23390 binding (Ki greater than 1 microM). Covalent photoaffinity labeling of the dopamine D2 receptor in bovine striatal membranes with N-(p-azido-m-[125I]iodophenethyl)spiperone [( 125I]N3-NAPS) was prevented by AES at nanomolar concentrations. The dopamine D2 receptor was solubilized from bovine striatal membranes using 0.25% cholate in the presence of high ionic strength, followed by precipitation and subsequent treatment with 0.5% digitonin. Nearly 100% of the [3H]spiperone-binding activity in the cholate-digitonin solubilized preparation was absorbed at a receptor-to-resin ratio of 2:1 (v/v). Dopamine D2 receptor was eluted from the affinity resin using a competing dopaminergic antagonist molecule, haloperidol. Recovery of dopamine D2 receptor activity from the affinity matrix was approx. 9% of the activity adsorbed to the resin. The [3H]spiperone-binding activity in AES-Sepharose affinity purified preparations is saturable and of high affinity (0.2 nM). Affinity-purified preparations maintain the ligand-binding characteristics of a dopamine D2 receptor as assessed by agonist and antagonist competition for [3H]spiperone binding.

Affinity Labels↗

In vivo partial body activation analysis using filtered neutron beam.

A facility for in vivo prompt gamma-ray activation analysis using a filtered neutron beam from a mobile nuclear reactor is described. The low-power nuclear reactor with a thermal neutron absorber provides a maximum neutron flux of 11,000 neutron/cm2.s in the liquid phantom positioned on the surface of the irradiation plane; uniformity of the neutron flux inside the phantom with unilateral and bilateral irradiations is investigated. The elemental concentration of toxic mercury in a body organ is determined from a rapid diagnostic irradiation with minimal radiation doses as well as high sensitivity.

Activation Analysis↗