PubMed Health⌕ Search

Biomedical subjects

Y C Chung

Publications and source records attributed to Y C Chung.

At least 55 records · Page 3Linked to original sources
PubMed1993

Complete transection of common bile duct due to blunt abdominal trauma: a case report and literature review.

A case of complete transection of the common bile duct due to abdominal blunt injury in a 49-year-old man is presented. The rarity of this injury and its initial presentation as a pancreatic pseudocyst warrant its description. This patient was diagnosed as having bile duct injury following ascites aspiration. Common bile duct transection was documented and a choledochostomy was done. However, bile leaked into the peritoneal cavity one week after the operation. A Roux-en-Y choledochojejunostomy was done successfully in a second operation. Delayed diagnosis is common in these kinds of injuries, but it should be considered when a patient has bile ascites, abdominal distention and jaundice after a blunt abdominal injury. A review of the literature, methods of diagnosis and the technique of surgical repair are described.

Cholangiography↗
PubMed1992

Rat liver regeneration after partial hepatectomy: effects of insulin, glucagon and epidermal growth factor.

This study evaluated the role of insulin, glucagon and the epidermal growth factor (EGF) on liver regeneration after partial hepatectomy. Male Wistar rats, weighing approximately 200 g, were used. A partial hepatectomy, with resection of the medial and left lateral lobes (67.31%), was performed on the control group and seven hormone-treated groups: insulin, glucagon, EGF, insulin plus glucagon, insulin plus EGF, glucagon plus EGF, and a combination of the three hormones. The hormones were administered subcutaneously two days prior to the partial hepatectomy. The groups administered insulin were allowed to drink 20% glucose in water. Another group of rats received simulated operations, i.e., only a laparotomy was performed. The rats were killed at six, 24, 48 and 72 hours after the operation. Remnant liver weight, deoxyribonucleic acid (DNA) content, rate of DNA synthesis, mitotic index, blood glucose and serum insulin levels were measured. The results showed that: 1) the effects of single hormone administration on posthepatectomy liver regeneration were not obvious; 2) combined administration of insulin and glucagon increased the weight of the remnant liver, the DNA content, and the rate of DNA synthesis; 3) the combined administration of insulin, glucagon, and EGF increased the regeneration based on the remnant liver weight and mitotic index; and 4) there was no concordance between the change in blood glucose levels and the effect of hormones during liver regeneration.

Animals↗
PubMed1992

Serum interleukin-2 and soluble interleukin-2 receptor in renal transplant recipients.

Interleukin-2 (IL-2) and soluble interleukin-2 receptor (sIL-2R), released during T-lymphocyte activation, were measured in serial samples of serum from 32 patients with renal allografts and other uremic patients. Patients undergoing chronic hemodialysis had elevated sIL-2R levels (1,801.93 +/- 753.23 U/mL) which dropped after stable renal transplantation (822 +/- 438 u/mL). However, these values were higher than those of a normal control group (397.3 +/- 84.5 u/mL, p < 0.01). Marked elevation of sIL-2R (1,503.78 +/- 640 u/mL) was noted in patients with acute rejection episodes compared to those in a stable allograft condition (p < 0.02) and those with cyclosporine nephrotoxicity (793.2 +/- 245.2 u/mL, p < 0.01), but returned to a stable level after successful anti-rejection treatment (745.91 +/- 345.8 u/mL, p < 0.01). Acute tubular necrosis and infection also showed a comparable rise in the sIL-2R level. The increase in sIL-2R with rejection was found one to four days earlier than the clinical diagnosis of acute rejection. There was a marked rise in the serum IL-2 level of uremic and post-transplant patients when compared to normal subjects (34.76 +/- 32.16 u/mL and 9.3 +/- 12.7 u/mL vs 4.38 +/- 3.38 u/mL, p < 0.001), but no significant differences were found between the IL-2 level of patients with acute rejection and cyclosporine nephrotoxicity or acute tubular necrosis (3.74 +/- 4.51 u/mL, 1.57 +/- 1.25 u/mL and 6.73 +/- 6.3 u/mL, p > 0.05). The diagnostic value of sIL-2R assay was more meaningful than that of IL-2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Monitoring of serum neopterin in renal transplant recipients.

Postoperative management of kidney allograft recipients requires a reliable and rapid diagnostic method so that proper therapy can be initiated. In this study, we tried to correlate serum neopterin levels with different conditions after transplantation. Serial serum neopterin levels were assessed after operation. Serum neopterin levels of uremic patients were significantly higher than those of healthy persons (239.9 +/- 177.7 nmole/L, n = 33 vs 6.14 +/- 2.78 nmole/L, n = 10, p < 0.001). In recipients with a stable post-transplant course, the serum neopterin level was low. On the contrary, acute rejection episodes were associated with a high level of serum neopterin which declined after successful treatment, although the difference was not significant (96.2 +/- 57.7 nmole/L vs 56 +/- 38.1 nmole/L, p > 0.05). The serum neopterin level was also high in post-transplant acute tubular necrosis (ATN, 256.6 nmole/L), which gradually declined parallel to the resolution of ATN. The neopterin level was low in patients with cyclosporine nephrotoxicity (17.8 +/- 7.6 nmole/L). In summary, the serum neopterin levels were persistently high in uremic and post-transplant ATN patients. Acute rejection episodes were correlated with an increased level of neopterin. It appears that daily measurement of the serum neopterin level may be useful for biochemical detection of immunologic complications in allograft recipients.

Adult↗
PubMed1991

Clinical manifestations of acute rejection in renal allograft recipients receiving cyclosporin-A therapy.

Cyclosporin-A-treated renal allograft recipients have demonstrated an improved graft survival rate, when compared to that of patients treated with conventional azathioprine and steroid therapy. Cyclosporin-A has been used for immunosuppressive therapy after renal transplantation at the National Taiwan University Hospital since November 1985. Since then, the one-year graft survival rate has been 78%, and the patient survival rate is 91%. At our service, acute rejection is confirmed mainly by an increase in the serum creatinine level of 0.5 mg% per day and a subsequent return of kidney function to normal after pulse steroid therapy. Twenty patients receiving cyclosporin-A and suffering from acute rejection episodes were chosen for comparison with 18 patients receiving conventional azathioprine and steroid therapy. Compared to conventional therapy, the classical systemic manifestations of rejection, such as malaise, lethargy, apathy, general weakness, vague discomfort, increase in body weight, swelling of graft with tenderness, were all more mild and less frequent in the cyclosporin-A-treated group. Episodes of rejection appeared earlier and the duration of rejection was shorter than in those of the conventional group. The urinary sodium concentration and the ratio of urine urea nitrogen to blood urea nitrogen were reliable references during the acute rejection episode in the conventional group, but it cannot be used as indices in the cyclosporine group. These findings can help us understand the changes which occurred in acute rejection in patients who receive renal transplantation during the cyclosporine era.

Adult↗
PubMed1991

The outcome of delayed graft function in cadaveric renal transplants treated with low dose cyclosporine.

Thirty-three consecutive cadaveric renal transplantations performed at the National Taiwan University Hospital from November 1985 to December 1989 were reviewed to determine the effect of early function on the 1-year patient and graft survival rates. Immediate function was present in 17 transplants; delayed graft function with acute tubular necrosis occurred in 16 cases. The 16 transplants with acute tubular necrosis (ATN) were treated with low dose cyclosporine. Among them, 13 patients had delayed function which resolved after 2 to 60 days of hemodialysis, but 3 grafts did not regain function. The allograft survival rate at 1-year was 68.7% for the delayed function group and 88.2% for the immediate function group. This difference was not statistically significant (p greater than 0.05). The 1-year patient survival rate was also not significantly different (87.5% vs 88.2%). There was no relationship between graft loss and duration of ATN. However, the graft survival rate in patients with a serum creatinine level below 2 mg/dL, after recovery either from ATN or non-ATN, was better than that for patients with a serum creatinine level of more than 2 mg/dL. The difference was statistically significant (95.8% vs 50.0%, p less than 0.02). It is concluded that delayed allograft function with acute tubular necrosis does not significantly alter the 1-year survival rates of patients and grafts in low-dose cyclosporine therapy. However, it is deleterious to the 1-year survival rate of an allograft when poor functional recovery occurs in an ATN or non-ATN condition.

Adult↗
PubMed1991

Lymphocele after renal transplantation: a case report.

A case of lymphocele after an allograft renal transplant at the National Taiwan University Hospital is reported. A 32-year-old female patient received a kidney transplant from a cadaver donor on 23 November 1990 after a 10-year course of hemodialysis. Acute tubular necrosis of 31 days duration developed on the 6th postoperative day after a severe episode of acute rejection. On the 44th POD, sonographic examination showed an echo-free space between the graft and the urinary bladder. Emergent marsupialization through an intraperitoneal window of the lymphocele was performed on the 45th POD due to a sudden decrease in urine output. After releasing the compression of the lymphocele, the urine output returned to over 2,500 mL on the following day. The patient was discharged on the 63rd POD with normal renal function. Repeated sonographic examination showed no reaccumulation of lymphocele. The literature concerning lymphocele is reviewed.

Adult↗
PubMed1989

Real-time signal acquisition and analysis for clinical dental electromyography using a microcomputer-based system.

The Electromyographic (EMG) Signal Acquisition and Analysis System is an integrated hardware and software system that digitizes multichannels of amplified EMG signals and stores them in user defined disc files before analysis. The software runs on all IBM PC and its compatibles with the appropriate analogue-to-digital (A/D) conversion board. Both time and frequency domain analyses can be computed on-line. This system provides a low cost method of digitizing and analysing EMG signals on real-time for clinical dental electromyography.

Adult↗
PubMed1983

Intestinal assimilation of a proline-containing tetrapeptide. Role of a brush border membrane postproline dipeptidyl aminopeptidase IV.

The mechanism of hydrolysis and absorption of a proline-containing tetrapeptide, Leu-Pro-Gly-Gly (10 mM) by rat intestine was examined in vivo by using jejunal perfusion methods. The peptide substrate and hydrolysis products were analyzed by use of an automated amino acid analyzer. Leucine, proline, and glycine were absorbed by the intestine at a significantly higher rate from the tetrapeptide than from an equivalent amino acid mixture. The analysis of the hydrolytic products in the lumen during in vivo perfusion of the tetrapeptide showed that two dipeptides, Leu-Pro and Gly-Gly, were the major products. These two dipeptides were also the major hydrolytic products when a purified rat intestinal brush border membrane preparation was incubated with Leu-Pro-Gly-Gly. The rate of hydrolysis of the tetrapeptide was much higher than that for several other proline-containing peptides (Leu-Pro, Pro-Leu, and Pro-Gly-Gly) that were tested. Studies using Gly-Pro-beta-naphthylamide, a specific substrate for postproline dipeptidyl aminopeptidase IV, showed that this enzyme is mainly localized to the brush border membrane and is responsible for the hydrolysis of the tetrapeptide into the two dipeptides Leu-Pro and Gly-Gly. Thus, brush border membrane dipeptidyl aminopeptidase IV very likely plays an important role at the intestinal mucosal cell surface in the final stages of digestion of proline-containing peptides.

Animals↗
PubMed1979

Amino acid and peptide absorption after proximal small intestinal resection in the rat.

In experimental animals with massive proximal intestinal resection, in vivo ileal absorption of an amino acid mixture containing L-leucine and glycine as well as two different dipeptides, L-leucyl-glycine and glycyl-L-leucine, were compared. Both amino acid and dipeptide absorption were markedly enhanced in the ileal segments. However, the absorption rates from the two perfused dipeptides differed. L-leucine absorption from L-leucyl-glycine was much greater than from glycyl-L-leucine. Brush border amino-peptidase activities after resection were also increased but dissociation between absorption and hydrolytic activity occurred. This study indicates that certain dipeptides are handled differently by adapting ileal segments. Furthermore, the changes observed probably reflect mucosal cellular hyperplasia occurring in association with intestinal adaptation.

Amino Acids↗
PubMed1979

Comparison of oral feeding of peptide and amino acid meals to normal human subjects.

Intestinal perfusion studies performed in man have suggested that amino acid nitrogen may be absorbed more rapidly from peptides than free amino acids. The aim of the present study was to compare the effects of the oral administration of peptides and free amino acids. Two isonitrogenous liquid test meals, one containing 50 g of a partial enzymic hydrolysate of fish protein in which approximately 80% of the nitrogen content was present as small peptides (peptide meal), and the other a mixture of free amino acids (amino acid meal) the composition and molar pattern of which simulated that of the peptide meal, were administered on separate occasions to six normal subjects intubated with a triple lumen tube. Both meals contained the reference marker polyethylene glycol. Fractional absorption of amino acid residues one and two hours after ingestion of the two meals was similar at three intestinal locations situated 120, 160, and 200 cm from the mouth of each subject, and at two hours 73.8% and 72.0% of the amino acid residues had been absorbed respectively by the time the contents of the peptide and amino acid meals reached the middle sampling port of the tube. The total sum of individual amino acid increments in plasma was significantly greater 30 minutes (p < 0.025) and one hour (p < 0.05) after ingestion of the peptide than amino acid meals. By three hours the total area under the two plasma curves was similar. Normal human subjects thus appeared to be capable of assimilating orally administered mixtures of peptides and free amino acids with equal efficiency. Secretion of fluid into the lumen of the upper small intestine, assessed by reference to dilution of the polyethylene glycol, was less after ingestion of the peptide meal. In clinical situations characterised by fluid and electrolyte malabsorption consideration might be given to using small peptides rather than free amino acids as the nitrogen source in nutritional diets.

Adult↗
PubMed1975

Purification and properties of the glutathione reductase of Chromatium vinosum.

The Chromatium vinosum glutathione reductase [NAD(P)H: glutathione disulfide oxidoreductase, EC 1.6.4.2] was purified to apparent homogeneity. The enzyme was found to require reduced nicotinamide adenine dinucleotide (NADH) as a reductant and to be specific for oxidized glutathione (GSSG). The polypeptide molecular weight in sodium dodecyl sulfate was found to be 52,000. Incubation of enzyme with NADH in the absence of GSSG resulted in a significant loss in activity. The enzyme was stimulated by phosphate and sulfate ion, but was inhibited by chloride ion, heavy metals, and sulfhydryl reagents. Adenylate nucleotides were inhibitory, and the data suggested that they were acting as competitive inhibitors of flavin adenine dinucleotide (FAD). The Km values of 7 X 10-3 for GSSG and 6 X 10-5 M for NADH were the highest reported of any previously investigated glutathione reductase. The order of addition of components markedly affected the response of the enzyme to FAD. A requirement for FAD (Km 5.2 X 10-7 M) was seen if the enzyme was incubated with NADH prior to GSSG addition, whereas no FAD was required if the order was reversed.

Adenosine↗