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Y Hwang

Publications and source records attributed to Y Hwang.

8 recordsLinked to original sources

A defined system for in vitro lambda DNA packaging.

We constructed a defined in vitro system for packaging lambda DNA which is composed of purified proheads, the noncapsid proteins terminase and gpFI, and the Escherichia coli DNA binding/bending protein IHF. The defined packaging system: (i) is free from endogenous ATP, DNAs, and DNases and (ii) packages 30% of the input mature lambda DNA efficiently. In this defined packaging system, IHF and gpFI make modest contributions to packaging efficiency. The defined packaging reactions showed that DNA packaging gave a linear response to the concentration of mature lambda DNA and terminase. DNA packaging showed a sigmoidal relationship with respect to the concentration of ATP and proheads.

Adenosine Triphosphate

Physicians' response to length-of-stay profiling.

One of the techniques adopted recently by certain hospitals to meet the competitive pressure for reducing costs is physician profiling. Profiling produces periodic reports that compare a physician's resource consumption to a benchmark figure. This study analyzes the effectiveness and implications of one hospital's introduction of physician patient length-of-stay profiling. Data for 24,000 patients treated by 400 physicians in 450 diagnosis-related groups over 42 months were analyzed, including both preprofiling and postprofiling periods. Statistical tests examined whether more physicians achieved the length-of-stay benchmark after profiling was introduced, controlling for physician, disease category (diagnosis-related group), and patient severity level. First, the results establish a significant increase in the percentage of physicians who achieve the length-of-stay benchmark after the introduction of profiling. Second, it was found that physicians who had initially failed to meet the benchmark reduced their patients' average length of stay much more than those physicians who initially achieved the benchmark. Further, reductions occurred primarily at intermediate severity levels, and in diagnosis-related groups with a large economic impact for the hospital. Although the profiling program did achieve the objective of reducing patient length of stay, further improvement may be possible. First, providing different benchmarks or targets for different physicians may extend the improvement to a greater percentage of all physicians involved. Second, an analysis of monthly data on total weighted procedures reveals that the reduction in length of stay resulted in an increase in the number of procedures performed per patient day. This finding suggests that to achieve a reduction in hospital costs and charges, profiling programs should be combined with process improvement initiatives.

Diagnosis-Related Groups

[The factors of diagnosis and treatment delay in the late stage of cancers in pharynx, larynx and oral cavity].

Cancers of pharynx, larynx and oral cavity (CPLOC) are the tumors can be easily found by patients themselves. Unfortunately, the diagnosis and treatment delay in CPLOC is very severe in our country. The study was based on the data collected through questionnaire from 100 patients with CPLOC in late stages. The causes of diagnosis and treatment delay in those patients were evaluated. The study reveals that traffic and financial difficulties are not the principal factors causing the delay. Instead, limited knowledge which the patients learned from television and newspapers, and sometimes bias cancer knowledge play major role in the delay. When the symptoms developed, 64% of the patients either did not pay attention to their symptoms, or took some improper medical treatments according to their own diagnosis. It took them 207 days on average from having the symptoms to consulting a doctor, about 108 days on average from consulting a doctor to getting a right suggestion. The latter delay was often caused by ambiguous and improper suggestion from doctors. However, if a patient receives a proper suggestion from a doctor, the major reason for diagnosis delay was that patients felt their symptoms were not severe or the examinations required too much time. Even if patients were confirmed to have cancer, treatment delay is still not avoidable as they often turned to Chinese herb doctors, took herb drugs, or feared of receiving an operation. Therefore, the best way of reducing treatment delay in CPLOC is to enhance medical knowledge and education, and to correct the image that traditional Chinese herbs are effective in curing CPLOC.

Adult

Expression of penicillin G acylase gene from Bacillus megaterium ATCC 14945 in Escherichia coli and Bacillus subtilis.

Penicillin G acylase gene from Bacillus megaterium ATCC 14945 has been isolated. Recombinant Escherichia coli clones were screened for clear halo forming activity on the lawn of Staphylococcus aureus ATCC 6538P using the enzymatic acylating reaction of 7-aminodeacetoxycephalosporanic acid (7-ADCA) and D-(alpha)-phenylglycine methylester. The gene was contained within a 2.8 kb DNA fragment and expressed efficiently when transferred from E. coli to Bacillus subtilis. A twenty times greater amount of enzyme was produced in B. subtilis transformant than that in B. megaterium. The purified enzyme from subcloned B. subtilis showed that the native enzyme consisted of two identical subunits, each with a molecular weight of 57,000. The enzyme was able to react on various cephalosporins, i.e., cephalothin, cefamandole, cephaloridine, cephaloglycin, cephalexin and cephradine.

Bacillus megaterium