Biomedical subjects

H J Shim

Publications and source records attributed to H J Shim.

24 records · Page 2Linked to original sources

PubMed1995

Pharmacokinetics and antitumour activity of a new anthracycline, DA-125, after intravenous administration to subcutaneously implanted Lewis-lung-carcinoma-bearing mice.

The pharmacokinetics and tissue distribution of M1-M4 were compared after intravenous (i.v.) administration of DA-125, 25 mg kg-1, to BDF1 mice (n = 5 at each sampling time) and subcutaneously implanted Lewis-lung-carcinoma-bearing BDF1 mice (n = 10 at each sampling time. The mean plasma concentrations of M1-M4 were not significantly different between the two groups of mice, and hence similar pharmacokinetic parameters for M1-M4 were obtained. The amount of M1 in the lung was significantly greater in the tumour-bearing mice than in the control mice, resulting in a greater AUAt in the tumour-bearing mice (18,600 against 8940 micrograms min g-1), and vice versa in the liver (962 against 3840 micrograms min g-1). However, the corresponding values for other tissues were comparable between the control and tumour-bearing mice. The amount of M1 was greatest in the lung for up to 2 h in the tumour-bearing mice. M2 was the predominant metabolite among M1-M4 excreted in 24 h urine by both groups of mice; 8.36 and 10.7% of the i.v. dose were excreted in 24 h urine as M2--expressed in terms of DA-125--by the control and tumour-bearing mice, respectively. The amount of M1 in the tumour mass reached a mean Cmax of 3.75 micrograms g-1 immediately after i.v. administration of DA-125 to the tumour-bearing mice, then declined very slowly to an amount that remained almost constant for up to 24 h. This suggested that M1 has high affinity for the subcutaneously implanted Lewis lung carcinoma. The antitumour activity, such as the increase in life span (ILS) and tumour growth inhibition (TGI) of DA-125, 6-48 mg kg-1, and adriamycin (ADM), 3-18 mg kg-1, were also compared in subcutaneously implanted Lewis-lung-carcinoma-bearing BDF1 mice after four weekly i.v. administration of the drugs on days 1,8,15, and 22 following tumour implantation. More than three out of six mice survived as tumour-free for longer than 70 d at a DA-125 dose range of 6-24 mg kg-1, but there were no tumour-free mice at any dose of ADM. Assuming ILS values higher than 30% to be effective, DA-125 doses ranging from 6 to 24 mg kg-1 were effective in increasing the life span, which ADM does only within the dose range of 6-12 mg kg-1.

Animals↗

PubMed1995

Improved transjugular intrahepatic portosystemic shunt patency with PTFE-covered stent-grafts: experimental results in swine.

PURPOSE: To evaluate the ability of stent-grafts made with polytetrafluoroethylene (PTFE) graft material to improve transjugular intrahepatic portosystemic shunt (TIPS) patency. MATERIALS AND METHODS: TIPS were created in 13 swine by using PTFE-covered stent-grafts. Uncovered TIPS were placed in 13 other swine. Twenty-one of 26 animals were followed up with portal venography for 3 months or until the shunt became severely stenotic. Five animals without severe stenosis were sacrificed before 3 months because of illness. RESULTS: At 4 weeks after TIPS placement, nine of 13 stent-graft TIPS were patent (< 50% diameter narrowing) compared with only one patent stent in 13 uncovered TIPS. Six of 13 stent-graft TIPS remained patent until the animals were sacrificed. In 11 of 12 uncovered TIPS, stenosis was most prominent in the parenchymal tract. In five of seven stent-graft TIPS, stenosis was most prominent in the hepatic vein above the end of the graft material. Bile leaks were discovered in six occluded uncovered TIPS and in two of the stent-graft TIPS. CONCLUSION: PTFE-covered stent-grafts significantly improved TIPS patency in swine (P < .01). However, stenosis in the hepatic vein led to late shunt malfunction in selected cases.

Animals↗

PubMed1994

Simultaneous determination of a new anthracycline, DA-125, and its metabolites M1, M2, M3 and M4 in plasma and urine by high-performance liquid chromatography.

A high-performance liquid chromatographic method was developed for the simultaneous determination of a new anthracycline, DA-125 (I), and its metabolites (M1, M2, M3, and M4) in rat plasma and urine using fluorescein as an internal standard. Compound I, a prodrug of M1, is a beta-alanine derivative of M1, and only M1 shows antineoplastic activity. The method involved extraction or deproteinization followed by injection of 80-100 microliters of the aqueous layer or supernatant onto a C18 reversed-phase column. The mobile phases were 1% acetic acid-isopropyl alcohol-methanol (70:20:10, v/v) or 5 mM of ion-pairing chromatography reagent (IPC B8)-isopropyl alcohol-methanol (70:20:10, v/v) for the extraction or deproteinization methods, respectively. The flow-rate was 1.5 ml/min for both methods. The column effluent was monitored by a fluorescence detector with excitation wavelength of 488 nm and emission wavelength of 556 nm. The detection limits for M1, M2, M3, and M4 in rat plasma and urine were 50 ng/ml for all compounds using the extraction method, and 100, 50, 50, 50, and 50 ng/ml for I, M1, M2, M3 and M4 in rat plasma respectively, using the deproteinization method. No interferences from endogenous substances, adriamycin or daunorubicin were found.

Animals↗

PubMed1991

Factors influencing the protein binding of bumetanide using an equilibrium dialysis technique.

Factors that influence the plasma protein binding of bumetanide were evaluated using equilibrium dialysis. It took approximately 12 h of incubation to reach an equilibrium between plasma and isotonic phosphate buffer of pH 7.4 containing 3% dextran using a Spectrapor 2 membrane (mol. wt cut-off = 12,000-14,000) in a water-bath shaker kept at 37 degrees C and at a rate of 50 oscillations per min. Bumetanide was fairly stable in both 4% human serum albumin (HSA) and in the isotonic phosphate buffer of pH 7.4 for up to 24 h. The binding of bumetanide to 4% HSA was constant (87.5 +/- 1.73%) at bumetanide concentrations ranging from 0.1 to 100 micrograms/ml. The extents of binding were 72.0, 83.3, 88.5, 90.2, 91.3 and 91.4% at albumin concentrations of 0.5, 1, 2, 3, 4 and 5 g/100 ml, respectively, and increased with a decrease in incubation temperature; the values bound were 94.6, 90.3 and 89.3% when incubated at 4, 22 and 37 degrees C, respectively. The binding of bumetanide was independent of the buffer composition used, the quantities of AAG (up to 0.32%), heparin (up to 40 units/ml), sodium azide (up to 0.5%) and anticoagulants (EDTA, heparin and citrate). The free fraction of bumetanide in rabbit plasma (2.91%) was significantly higher than in humans (1.98%) or rats (1.85%).

Blood Proteins↗

PubMedDate not supplied

Recanalization of obstructed Tenckhoff peritoneal dialysis catheter: wire/stylet manipulation combined with endoluminal electrocauterization.

We report the results of fluoroscopically guided wire/stylet manipulation combined with endoluminal electrocauterization in seven patients with obstructed Tenckhoff peritoneal dialysis catheters. In preparation for clinical application, electrocauterization was performed using a stone basket to recanalize surgically removed Tenckhoff catheters obstructed with omental fat ingrowing through the side holes. All ingrowing omental fat was removed easily by electrocauterization with the rotating movement of a stone basket. The technique was then applied in vivo in seven cases with ingrowing omental fat and malpositioned catheter; six (86%) were successfully recanalized. Among those six cases with initial success, four maintained good catheter function with durable patency (mean 261.3 days). No significant complication was noted.

Adult↗

PubMedDate not supplied

Tuberculous aneurysm of the abdominal aorta: endovascular repair using stent grafts in two cases.

Tuberculous aneurysm of the aorta is exceedingly rare. To date, the standard therapy for mycotic aneurysm of the abdominal aorta has been surgery involving in-situ graft placement or extra-anatomic bypass surgery followed by effective anti-tuberculous medication. Only recently has the use of a stent graft in the treatment of tuberculous aortic aneurysm been described in the literature. We report two cases in which a tuberculous aneurysm of the abdominal aorta was successfully repaired using endovascular stent grafts. One case involved is a 42-year-old woman with a large suprarenal abdominal aortic aneurysm and a right psoas abscess, and the other, a 41-year-old man in whom an abdominal aortic aneurysm ruptured during surgical drainage of a psoas abscess.

Adult↗