Biomedical subjects
Publications and source records attributed to S Y Su.
OBJECTIVE: The objective of our study was to evaluate prospectively the preoperative use of 16-MDCT angiography and cholangiography in determining the resectability of Klatskin tumors. CONCLUSION: Preoperative MDCT angiography and cholangiography gave a good assessment of the degree of vascular and biliary involvement of the Klatskin tumor.
To analyze the capability of IL-1 and IL-6 in the induction of chemokine (CF) production by mouse thymus epithelial cell (MTEC1) clones, MTEC1 cells were cloned through one cell culture and individual cell clones were established in long term culture referred to as MTEC1-DW clones. The constitutive production of IL-1, IL-6 and CF by MTEC1-DW clones was evaluated and the patterns of the cytokine production determined. Addition of exogenous IL-1 or IL-6 or both to the cultures of those MTEC1-DW clones that are unable to produce CF, and incubated for 2 days, then, to assess the chemotactic activity in the cell culture supernatants (SNs). In the opposite, addition of anti-IL-1 mAb(s) to the cultures of those MTEC1-DW clones that can produce IL-1 and CF to neutralize secreted IL-1 then, to test chemotactic activity in the SNs after 2-day incubation. The results showed that in the MTEC1-DW clones which were unable to constitutively produce IL-1 or CF, addition of IL-1 could induce these cloned cells to produce CF with high chemotactic activity. By constrast, addition of anti-IL-1 mAb(s) to those MTEC1-DW clones that constitutively produce IL-1 and CF could significantly inhibit them to produce CF. IL-6 only exhibited weak activity in the induction of CF production by those cloned cells. Therefore, in the cytokine network regulation, CF production is mainly induced by endogenously produced IL-1 in MTEC1 cells.
Sso7d and Sac7d are two small (approximately 7,000 Mr), but abundant, chromosomal proteins from the hyperthermophilic archaeabacteria Sulfolobus solfataricus and S. acidocaldarius respectively. These proteins have high thermal, acid and chemical stability. They bind DNA without marked sequence preference and increase the Tm of DNA by approximately 40 degrees C. Sso7d in complex with GTAATTAC and GCGT(iU)CGC + GCGAACGC was crystallized in different crystal lattices and the crystal structures were solved at high resolution. Sso7d binds in the minor groove of DNA and causes a single-step sharp kink in DNA (approximately 60 degrees) by the intercalation of the hydrophobic side chains of Val 26 and Met 29. The intercalation sites are different in the two complexes. Observations of this novel DNA binding mode in three independent crystal lattices indicate that it is not a function of crystal packing.
An automated technique involving switching valves and a filter assembly has been developed and evaluated for the on-line precipitation of proteins and peptides from plasma samples. In the set-up, the proteins were precipitated on-line by injecting the plasma sample into a stream of organic precipitating agent. The precipitates so formed are filtered on-line by a set of filter assemblies consisting of ordinary in-line HPLC solvent filters. Evaluation of the technique was performed using ibuprofen and a mixture of three estrogens, estradiol, equilin and estrone, spiked in dog plasma. The coefficients of variation (C.V.) for system suitability parameters were below 10%. Absolute recovery of ibuprofen in plasma ranged from 80% for 100 micrograms/ml to 114% for 5 micrograms/ml spiked concentrations, respectively. Resolution for equilin and estrone, two closely eluting peaks, was 1.79 (C.V. = 5.8%, n = 7). The switching-valve--filter assembly had no significant effect on the efficiency of the HPLC system.
Kaohsiung is a city of 1.5 million located in the southern part of Taiwan. It has a serious air pollution problem mainly attributable to much industrial and commercial activity. In order to estimate the effects of traffic, season, and meteorological conditions on the mutagenicity of Kaohsiung City's urban ambient particulate matter, 624 airborne particulate samples were collected on a weekly basis from 12 locations for an entire year. The mutagenic potential of acetone extracts of air samples was evaluated by the Salmonella/microsomal test with S. typhimurium TA98 in the presence and absence of S9 mixtures. The air samples from November 1990 showed the highest direct and indirect mutagenicity among the 12 months, whereas those from June and July 1991 had the lowest direct and indirect mutagenic activity, respectively. The mutagenicity showed a good correlation with amounts of the acetone extractable matter of airborne particulates. The meteorological conditions, monthly mean precipitation, and wind speed also showed a good correspondence with mutagenicity. Wind direction and temperature had a moderate relationship. The major mutagenic fractions of air samples that had the highest mutagenic activity in a month were purified using Sephadex LH-20 column chromatography, and the contents of PAHs, 1-NP, and DNPs were analyzed by HPLC. The characteristic concentration ratios of PAHs indicated that, for the main pollution sources of airborne particulates from Kaohsiung city, the mobile sources were more important than the stationary ones. The total amounts of 1-NP and DNPs in airborne particulates seemed to correspond to their mutagenicity. Although the total amounts of 1-NP and DNPs in the air samples correlated with their mutagenicity, the major mutagenic chemicals in the airborne particulate samples from Kaohsiung City need further investigation.
The clinical manifestations of sodium bromate intoxication include among others acute renal failure and deafness. Most of the toxic manifestations are reversible with the exception of renal failure and deafness. This patient ingested about 7.5 g of sodium bromate powder, which produced gastrointestinal irritation, hypotension, fatigue, deafness, acute renal failure, anemia and peripheral neuropathy. Hemodialysis was performed three times due to acute renal failure, although the renal function improved, it did not recover completely. The patient was discharged with BUN: 42 mg/dL and creatinine: 3.4 mg/dL; she was still deaf.
Ultrastructural changes of the myocardia of rats with chronic hypoxia for 40 and 60 days are reported. The rats were caged in a hypobaric chamber simulating an altitude of 5000 meters above sea level. The heart functions were examined before myocardial specimens were taken from both ventricles for electron microscopy study. The results indicated that the myofibril structure of the right ventricle remained normal in the 40 days hypoxic group, except for the occasional appearance of obscure or disappearing Z lines. The mitochondria were slightly increased in number, with a disarrangement of the mitochondria and structural changes in the cristae. The myofibrils of the 60 days hypoxic group showed more obvious structural changes, with disruption of myofilaments. Structural changes in the right ventricle were consistent with apparent decompensation of the right ventricle. The changes of myocardium and mitochondria in the left ventricle were similar to but less sever than those in the right ventricle, and this observation corresponds with a less severe decompensation of the left ventricle. The data suggest that during chronic hypoxic exposure, a decline occurring after the peak increase of cardiac compensation might signal the onset of structural changes of the myocardium.
Anesthesia for patients with muscular dystrophy is a great challenge to the anesthesiologists. A 56-year-old female with muscular dystrophy was diagnosed as having colon cancer. Since surgical intervention was indicated, epidural anesthesia with double catheters was performed. The entire anesthetic course was uneventful. Based on the experience obtained, it is concluded that epidural anesthesia offers a good alternative to general anesthesia for major abdominal surgery complicated by muscular dystrophy.
During September-November, 1985, four employees of a factory were seen at the occupational clinic complaining of cough, shortness of breath, and wheezing. All four worked in the same area of the factory where an adhesive containing toluene diisocyanate (TDI) was applied to velcro-like tape during manufacturing. To confirm the diagnosis of TDI-induced asthma and determine the prevalence among workers, 38 workers were interviewed and examined (84%) in the factory. Air samples were also taken from several areas in the factory to determine the TDI concentration. For analysis, the factory was divided into three areas based on the concentration of TDI: low (0.012 +/- 0.002 ppm), medium (0.021 +/- 0.006 ppm), and high (0.047 +/- 0.054 ppm). The distribution of workers with symptoms of asthmatic bronchitis was highly associated with TDI concentration (p less than 0.001). After stopping work for a period of 10 days, workers in areas with a high concentration of TDI showed marked improvement in pulmonary function tests (PFTs). After isolation of the exposure site, improvement of the ventilation system, and substitution of the TDI with less volatile diphenylmethane diisocyanate (MDI), air concentration of isocyanates was usually below 0.007 ppm. Three of the four clinically overt asthma cases went back to work without any difficulty. The PFTs of affected workers showed a significant improvement 5 months later. We conclude that TDI was responsible for the occupational asthma among velcro-like tape manufacturers and that the TDI-induced impairment of pulmonary functions was at least partially reversible.
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