Search PubMed⌕ Search

Biomedical subjects

S J Hwang

Publications and source records attributed to S J Hwang.

At least 163 records · Page 9Linked to original sources
PubMed1992

[Comparison of anesthetic morbidity and mortality before and after the implementation of quality assurance in Tri-Service General Hospital].

The desire to improve anesthetic outcome is a cornerstone in modern anesthesia. There are many means to reach this goal, such as enforcement in personal training, elevation of monitoring standards, constant vigilance and stern quality assurance (QA). The department of Anesthesiology, Tri-Service General Hospital, has adopted the QA program and implemented it since March 1, 1990. Because there were no significant differences in terms of personnel training, monitoring standards and types of anesthesia and surgery before and after the application of QA program, we investigated the effects of QA on anesthetic major morbidity and coma/mortality. We analyzed the anesthetic results obtained in two separate periods respectively spanning from Jan. 1, 1989 to Dec. 31, 1989 and from Mar. 1, 1990 to Feb. 28, 1991. During the first two months of 1990, the department's personnel were trained to be familiar with the QA program. We compared the anesthetic major morbidity and coma/mortality of one year before the implementation of QA with those in a one-year period after its implementation. Before and after enforcement of QA, there were no significant differences (p greater than 0.05) regarding major morbidity and coma/mortality, but the rates of anesthetic complications were lower after the practice of QA program. Since the functions of QA was aimed at alerting the anesthetic personnel to keep constant vigilance over the act of anesthesia, QA in theory could reduce anesthetic accidents and mishaps related jointly to surgery and anesthesia. The reason why QA did not decrease anesthetic major morbidity and coma/mortality in this study may be due to limited number of anesthesia in relatively short period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

A prospective study of post-transfusion non-A, non-B (type C) hepatitis following cardiovascular surgery in Taiwan.

In an attempt to investigate the incidence and clinical course of non-A, non-B (NANB) hepatitis following blood transfusion in Taiwan, 288 patients who underwent cardiovascular surgery and received blood transfusion were followed prospectively with serum liver aminotransferase levels and viral hepatitis markers for at least six months. None had any past history of liver disease or drug abuse. All blood donors were tested for serum hepatitis B surface antigen and alanine aminotransferase (ALT) (greater than 45 U/L). Thirty-seven (12.8%) patients developed PTH. 34 (91.9%) were considered to be cases of NANB hepatitis, 2 (5.4%) were cytomegalovirus hepatitis, and one (2.7%) was caused by Epstein-Barr virus. No one developed hepatitis B post-transfusion hepatitis (PTH). Of the 34 NANB PTH patients, 15 (44.1%) were asymptomatic, 16 (47.1%) had clinical symptoms, and 9 (26.5%) had serum total bilirubin levels higher than 2 mg/dl. There was no case of fulminant hepatic failure. Of 26 NANB PTH patients who were followed up for more than one year, 15 (57.7%) still had abnormal serum ALT levels. The incubation period of NANB PTH ranged from 2 to 16 (mean 6.1 +/- 3.2) weeks. Of the 37 PTH patients, 32 (86.5%) were found to have anti-HCV seroconversion during one year follow-up period. NANB PTH is as common in Taiwan as in the United States and Japan, and is demonstrated by this study to be due mostly to HCV.

Adolescent↗
PubMed1991

Growth hormone heterogeneity in American plaice pituitaries: isolation, characterization, and partial amino acid sequence.

Growth hormones (GHs) have been isolated from pituitary glands of American plaice (Hippoglossoides platessoides), a marine flatfish, using affinity and gel filtration chromatography, followed by preparative polyacrylamide gel electrophoresis (PAGE). A bioassay based on serum triiodothyronine elevation in immature rainbow trout was used to monitor biological activity. These GHs originate from two molecular mass regions, 42K and less than 33K relative molecular mass (Mr), in their native state. The 42K Mr region yielded two forms of GH, which differ in terms of quantity and net charge as evidenced by native PAGE, a major variant with a relative mobility of (Rf) 0.22 and a lesser variant with Rf 0.28. The less than 33 Mr region has a single GH species with Rf 0.22. Upon sodium dodecyl sulfate-PAGE, without reduction, both GH variants from the 42K Mr region gave Mrs of 21K, while the GH from the less than 33K Mr region was 20K Mr, typical of monomeric vertebrate GHs. The proteins composing the 42K Mr region are proposed as GH dimers since they yield 21K Mr peptides. The less than 33K Mr region contains a GH monomer (20K Mr) in its native state. An amino-terminal amino acid sequence, identical for both the 42K and the 20K Mr Rf 0.22 forms, has good homology with other complete fish GH sequences near their carboxyl-terminal regions (between amino acids 130 and 196). The GH dimers (42K Mr) predominate in the plaice pituitary, contributing 93% of the total, of which 86% gives rise to the Rf 0.22 variant.

Amino Acid Sequence↗
PubMed1991

Isolation of sockeye salmon growth hormone utilizing serum triiodothyronine enhancement in rainbow trout to monitor biological activity.

Growth hormone (GH) was isolated from sockeye salmon (Oncorhynchus nerka) pituitary glands using established techniques of affinity and gel filtration chromatography, and preparative polyacrylamide gel electrophoresis. The GH activity was followed throughout the fractionation procedure with a bioassay based on the increase of serum triiodothyronine (T3) in rainbow trout (Oncorhynchus mykiss), measured by radioimmunoassay (RIA). Amino-terminal amino acid sequence analysis and subsequent comparison with established GH sequences from other Oncorhynchus sp. were used to confirm the isolation of sockeye salmon GH (ssGH). The bioassay was sensitive to a dose of 55 ng of purified ssGH/g fish. Monomeric GHs, located in the carbohydrate-poor protein fraction, were the only pituitary components that elevated serum T3. Twenty-four hours after GH injection was an appropriate and practical time to blood sample, allowing completion of the bioassay, including RIA, in 3 days. The generic homology, between the source of pituitaries and the bioassay animals used in this study, should permit the bioassay to be useful during GH isolation from pituitaries of all Oncorhynchus sp.

Analysis of Variance↗
PubMed1991

Antibodies to hepatitis C virus in prospectively followed patients with posttransfusion hepatitis.

In an attempt to investigate the incidence and clinical course of type C viral hepatitis among patients with posttransfusion hepatitis, antibodies to hepatitis C virus (anti-HCV) in sera were measured from 42 prospectively followed cardiovascular surgery patients who developed hepatitis after blood transfusions. Of these, 35 (83.3%) had anti-HCV seroconversion during a 6- to 12-month follow-up period. The mean interval between blood transfusion and onset of active anti-HCV seroconversion was approximately 3 months after the first elevation of serum alanine aminotransferase levels (18.1 vs. 6.4 weeks). There was no correlation between fluctuations in serum alanine aminotransferase levels and anti-HCV titers. Of 26 patients with type C posttransfusion hepatitis who were followed greater than 1 year, 20 (76.9%) continued to have abnormal serum alanine aminotransferase levels. The results indicate that HCV is the major agent of posttransfusion hepatitis in Taiwan. Furthermore, it plays an important role in chronic hepatitis among transfused patients.

Adult↗
PubMed1991

Plasma atrial natriuretic peptide and natriuretic response to water immersion in patients with nephrotic syndrome.

Eight nonnatriuretic (daily Na excretion less than 50 mEq), 4 natriuretic (daily Na excretion greater than 50 mEq), and 4 steroid-responsive nephrotic patients, and 12 normal controls were studied with a 4-hour water immersion with measurements of electrolytes, plasma atrial natriuretic peptide (ANP), plasma renin activity (PRA), and plasma aldosterone (PA) [corrected]. Four nonnatriuretic patients further received 25 g albumin infusion, with a subsequent 2-hour water immersion study. The results are as follows: (1) In the nonnatriuretic patients, the extremely low basal Na excretion rate, high PRA, and PA levels indicated a state of active Na retention. In spite of the water-immersion induced suppression of PRA and PA and a comparable magnitude of plasma ANP increment, the natriuretic response to water immersion was blunted in the nonnatriuretic patients. (2) In the natriuretic patients, water immersion resulted in a similar magnitude of natriuresis but a higher degree of plasma ANP increment in comparison to the normal controls. (3) Natriuretic and plasma ANP responses to water immersion were not different between the steroid-responsive patients and normal controls. (4) The increase in plasma ANP and the suppression of PRA and PA after 25 g albumin infusion did not result in natriuresis until the further suppression of PRA and PA and the further stimulation of plasma ANP by subsequent water immersion. The above results indicate that the natriuretic and plasma ANP responses to water immersion are related to the basal Na status in nephrotic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Superinfection with hepatitis C virus in patients with symptomatic chronic hepatitis B.

11/323 patients (3.4%) with symptomatic chronic hepatitis B were positive for antibody to hepatitis C virus (anti-HCV). The positive rate of anti-HCV in patients with serum alanine aminotransferase (ALT) levels greater than 200 U/l (n = 219) did not exceed that of the patients with ALT less than or equal to 200 U/l (n = 104) (2.7% vs. 4.8%). Of the 219 patients who were positive for hepatitis B e antigen (HBeAg) and/or hepatitis B virus-DNA (HBV-DNA), 5 (2.3%) had anti-HCV, while 6/104 patients (5.8%) who were positive for antibody to HBeAg (anti-HBe) had anti-HCV (p greater than 0.1). In contrast to the anti-HCV-negative patients, the patients with anti-HCV had a higher percentage of cirrhosis in their liver histological findings (36.4% vs 5.4%, p less than 0.005). In conclusion, the prevalence of HCV superinfection in symptomatic chronic hepatitis B patients is low and HCV superinfection is not an important factor in acute exacerbation of chronic hepatitis B. However, the superinfection with HCV may exacerbate the existing liver disease and accelerate its progression.

Adolescent↗
PubMed1991

[Studies on antiaggregating drugs of horseshoe crab amebocytes].

The effects of drugs on amebocyte spontaneous aggregation and endotoxin induced aggregation were studied. N-Ethylmaleimide, ethylenediamine tetraacetate, propranolol, verapamil and lidocaine but not dibutyryl cyclic AMP could reduce the aggregating rate of amebocytes. The speed of degranulation induced by endotoxin was reduced by N-ethylmaleimide, ethylenediamine tetraacetate, propranolol, verapamil and caffeine. These results suggest that Ca+2 and c-AMP may play an important role in amebocyte spontaneous aggregation and endotoxin induced aggregation. The blocking agent of Ca+2 and c-AMP can also antagonize the aggregation of amebocytes.

Animals↗
PubMed1991

Hamartoma of spleen: a case report.

Hamartoma of the spleen is a rare benign tumor. Only about 105 cases in English-writing literature were reported after first description by Rokitansky in 1861. We reported one case of asymptomatic splenic hamartoma in Taiwan which was found incidentally by ultrasonographic examination. Ultrasonography of abdomen revealed a slightly hypoechoic and nearly isoechoic tumor mass in the spleen. Computed tomography of the abdomen revealed a well-defined, low-attenuation mass in the spleen, which became isodense after contrast injection. Celiac arteriography and superselective splenic arteriography revealed a hypervascular mass with fine tumor vessels and tumor stains in the spleen. Splenectomy was performed and the microscopic examinations revealed typical red-pulp type hamartoma of the spleen.

Adult↗
PubMed1990

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↗
PubMed1990

Plasma atrial natriuretic peptide in patients with chronic renal failure.

Plasma atrial natriuretic peptide (ANP) levels were measured in non-dialyzed and dialyzed chronic renal failure (CRF) patients and in normal subjects. Changes in plasma ANP in response to hemodialysis (HD) and to isolated ultrafiltration (UF) were also investigated in dialyzed CRF patients. Plasma ANP levels were significantly higher in 28 non-dialyzed CRF patients than in 27 normal subjects (mean +/- SEM, 174.0 +/- 25.9 vs 25.0 +/- 1.9 pg/ml, p less than 0.001). Plasma ANP levels did not correlate with blood urea nitrogen or serum creatinine, however patients with advanced renal failure (creatinine clearance less than 10 ml/min) with cardiomegaly (cardiothoracic ratio greater than 50%) or hypertension (BP greater than 140/90 mmHg) had significantly higher plasma ANP levels than those who were not. A 6-hour HD significantly decreased the plasma ANP level (423.4 +/- 71.3 to 220.6 +/- 40.0 pg/ml, p less than 0.001) and body weight in 21 dialyzed CRF patients, and the decrement in plasma ANP showed a positive correlation with the decrement in body weight (r = 0.425, p = 0.056). In 8 dialyzed CRF patients, we further performed a 1-hour isolated UF for removal of isoosmotic intravascular fluid without changes in the solute concentrations, followed by a subsequent 5-hour HD. The decrease in plasma ANP during the 1-hour UF period was 68% of the total ANP decrement for the whole 6-hour study. The average plasma ANP level was decreased with 94.6 +/- 42.5 pg/ml/kg/h in the UF period compared to 3.5 +/- 1.4 pg/ml/kg/h in the HD period (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Metastatic malignant melanoma of upper gastrointestinal tract.

A 74-year-old male patient developed intermittent melena and anemia after he had received surgical resection for malignant melanoma of the right foot and radical dissection of the right inguinal metastatic lymph node. The source of bleeding was identified to be metastatic melanoma of stomach and duodenum by panendoscopy and biopsy. Patient refused surgical intervention and died of pneumonia two weeks later.

Aged↗
PubMed1990

Study of plasma neuropeptide Y (NPY) and catecholamines levels during isoflurane anesthesia.

Twelve ASA physical status I-II patients were studied after obtaining institutional approval and informed contents. All patients were free from endocrine and metabolic disease undergoing elective low risk operation. Pethidine 1 mg/kg i.m. and benzodiazepine 0.01 mg/kg p.o. were given as premedication one hour before anesthesia. Anesthesia was induced with thiopental 4 mg/kg and succinylcholine 1.5 mg/kg for tracheal intubation. Anesthesia was maintained with 2% isoflurane and 50% N2O in oxygen. Ventilation was controlled and adjusted to maintain an end-tidal CO2 concentration of 25-35 torr. Atracurium 0.4 mg/kg was given as muscle relaxant. Blood samples were obtained from radial arterial catheter, 15 minutes before induction of anesthesia and 5 min after anesthesia, 15 min, 30 min, 60 min during operation and 30 min after operation in postanesthesia recovery room. The results showed that there were no statistically significant changes in plasma levels of NPY and catecholamines during operation underwent isoflurane anesthetic technique. This result indicates that isoflurane anesthesia can block the plasma NPY as well as catecholamines during surgical stress.

Adult↗
PubMed1989

Regulation of antifreeze protein production in winter flounder: a unique function for growth hormone.

Salmon pituitary extract and the protein fraction unabsorbed on concanavalin A-Sepharose, the carbohydrate-poor fraction, depressed plasma levels of antifreeze proteins (AFP) when the pituitary fractions were administered to flounder in late fall or winter. The active pituitary protein occurred in the fraction with a mean molecular weight of 25,000. The two major isohormones of growth hormone (GH) were the only biologically active proteins identified from the pituitary. Hypophysectomized flounder synthesize AFP in the spring and the two isohormones of GH suppress the synthesis. The fraction of flounder pituitaries containing putative GH depressed flounder plasma levels of AFP in late fall.

Acclimatization↗
PubMed1989

Isolation of an ammonium or methylammonium ion transport mutant of Escherichia coli and complementation by the cloned gene.

During nitrogen-limited growth, Escherichia coli expresses a specific ammonium or methylammonium ion transport system (Amt). Strains carrying defects in Amt have been isolated following Tn10 transposon mutagenesis. These mutants have less than 10% of the transport activity of the parental strain. Glutamate, glutamine, arginine, or high levels (20 mM) of ammonium will serve as the sole nitrogen source for growth of these strains, and glutamine synthetase is normally expressed and repressed by the nitrogen regulatory (Ntr) system. When transformed with plasmid pGln84, containing lacZ fused to an Ntr promoter (glnLp), the Amt mutants expressed a normal level of beta-galactosidase. Furthermore, P1 bacteriophage transduction of the amt mutation into an Ntr mutant, normally constitutive for Amt, gave Amt- transductants. Therefore, the mutations are unlikely to lie within genes affecting Ntr elements. Following transformation with plasmid libraries of E. coli genomic DNA constructed in pUC9, two plasmids conferring the Amt+ phenotype on the amt mutants were isolated. These plasmids were unable to complement the Amt- phenotype of Ntr- mutants. Restriction digestion of these plasmids revealed common fragments, and Southern blot analyses indicated that the Amt-complementing sequence and the site of Tn10 insertion in the genome occur in the same 3.4-kilobase HindIII-SalI fragment. Insertion of TnphoA into this fragment produced amt::phoA fusions which gave high levels of alkaline phosphatase under nitrogen-limiting conditions but low levels during ammonia excess. This suggests that the amt product contains domains which are exported to the periplasm.

Ammonia↗
PubMed1989

[The role of ADP-cyclic AMP system in horseshoe crab amebocytes aggregation and gel formation].

A study of the effects of ADP and cyclic AMP related drugs on gel formation induced by endotoxin and amebocytes aggregation was conducted. The gel formation induced by endotoxin could be inhibited by ADP, cyclic AMP, ATP and aminophylline. Conversely, Phosphodiesterase enhanced gelation rate. A calmodulin antagonist, trifluoperazine, also inhibited endotoxin-induced gel formation, but this agent was able to induce potentiation in amebocytes aggregation. These results suggest that the cyclic AMP phosphodiesterase system may play an important role in endotoxin-induced gel formation, and it was concluded that, in the presence of both Ca++ and endotoxin, the calmodulin-like protein will activate the cyclic AMP phosphodiesterase system and decrease the concentration of cyclic AMP, thus promoting gel formation.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1988

Molecular cloning and expression of salmon prolactin cDNA.

Prolactin was purified from chum salmon pituitaries. It was resolved into two variants by reverse-phase high-performance liquid chromatography. A cDNA library was prepared from Pacific chinook salmon pituitaries. Salmon prolactin gene was screened using a synthetic oligonucleotide based on partial protein sequence. A positive clone (PRL-10) was identified and sequenced. It is a full-size clone containing 1.1 kb and coding for a preprolactin of 211 amino acids. A modified prolactin plasmid (PRL-10A), in which the 5' untranslated sequence and the nucleotide sequence coding for the signal peptide of prolactin were deleted, was reconstructed into an expression vector using the heat-inducible lambda pL promotor. Mature prolactin, a single polypeptide of 22 kDa, was efficiently expressed in the bacteria at an elevated temperature.

Amino Acid Sequence↗