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Biomedical subjects

H B Lee

Publications and source records attributed to H B Lee.

At least 145 records · Page 8Linked to original sources
PubMed1989

Natural history and prognostic factors of primary hepatocellular carcinoma: study of 70 untreated patients.

We carried out a study of the clinical courses of 70 untreated patients with primary hepatocellular carcinoma (HCC) in order to evaluate their survival period and the prognostic factors. The median survival was two months. We evaluated ten variables of biochemical parameters and findings of hepatic scintigraphy. Among them, six variables were chosen by univariate analysis. They were serum bilirubin (cut-off value 3.0 mg/dl), alkaline phosphatase (150 IU/ml), aspartate aminotransferase (AST) (200 IU/ml), alanine aminotransferase (ALT) (50 IU/ml), reticuloendothelial (RES) dysfunction (grade 1) and multiplicity of space occupying lesions (SOL). Multivariate analysis identified three variables. The RES dysfunction and multiplicity of SOL by hepatic scintigraphy and bilirubin were considered as important prognostic factors. We found that the functional reservoir of the underlying liver and multiplicity of the origin of the tumor were the most important prognostic factors.

Adult↗
PubMed1989

Peritoneal solute clearances after four years of continuous ambulatory peritoneal dialysis (CAPD).

In order to evaluate peritoneal membrane function and responsiveness of peritoneal microcirculation to vasoactive agents in long-term continuous ambulatory peritoneal dialysis (CAPD) patients, we studied peritoneal clearances of urea (Curea) and creatinine (Ccr), protein concentrations in drained dialysate (DPC), peritoneal glucose absorption (% GA), and drained dialysate volume (VD) before and after nitroprusside (NP) addition to dialysis solution in 17 long-term CAPD patients (mean duration of CAPD: 52 months) and the results were compared to those of 18 patients who were just trained for CAPD (mean duration: 0.6 month). There were no differences in the control (without NP) Curea, Ccr, DPC, %GA, and VD between the new and long-term CAPD patients. Curea, Ccr, and DPC increased significantly with NP in both new and long-term patients. Curea and Ccr with NP were not different between the new and long-term patients but DPC with NP was significantly lower in the long-term CAPD patients. The results of this study suggest that peritoneal solute clearances and the responsiveness of peritoneal microcirculation to NP remain unchanged after four years of CAPD, despite recurrent episodes of peritonitis.

Biological Transport↗
PubMed1989

Omeprazole compared with ranitidine once daily in the treatment of duodenal ulcer.

A double-blind randomized study in 230 Malaysian patients with duodenal ulcer was conducted to compare the proton-pump inhibitor, omeprazole 20 mg, given once daily in the morning, with ranitidine 300 mg, administered once daily at night. After 2 and 4 weeks of treatment, 222 and 220 patients, respectively, were evaluable according to the study protocol. Omeprazole produced significantly higher healing rates than ranitidine at both 2 weeks (75% versus 46%, respectively, P less than 0.0001) and 4 weeks (97% versus 83%, respectively, P = 0.001). Ulcer symptoms were relieved more rapidly by omeprazole than ranitidine. After 2 weeks, daytime epigastric pain was reported by 30% of ranitidine-treated patients but only by 15% of omeprazole-treated patients, which is a statistically significant difference (P = 0.004). No major clinical or biochemical side effects were recorded for either omeprazole or ranitidine. In conclusion, omeprazole 20 mg was found to be superior to ranitidine 300 mg administered once daily for the treatment of duodenal ulcer as measured by ulcer healing and pain relief.

Adult↗
PubMed1989

Technetium-99m MAG-3 clearances after captopril in experimental renovascular hypertension.

Rats with one kidney clamped (2K1C), both kidneys clamped (2K2C), unilaterally nephrectomized with remaining kidney clamped (1K1C), and normals, were studied using 99mTc mercaptoacetyltriglycine ([ 99mTc]MAG-3) and 131I orthoiodohippurate ([131I]OIH). Clearances of [99mTc]MAG-3 and [131I]OIH were performed after constricted rats became hypertensive. Clearances were repeated after i.v. Captopril. Clearances of [99mTc]MAG-3 and [131I]OIH in normals didn't change significantly after Captopril. Clearances of [99mTc]MAG-3 and [131I]OIH decreased insignificantly after Captopril in the 2K2C model. in the 2K1C group, normal kidney clearance increased ([99mTc]MAG-3 p less than 0.01 and [131I]OIH p less than 0.025) and clamped kidney clearance decreased after inhibition ([99mTc]MAG-3, p less than 0.01, [131I]OIH p less than 0.02). Clearances increased in the 1K1C group after Captopril ([99mTc]MAG-3 p less than 0.0025 and [131I]OIH, p less than 0.001). The ratio of [99mTc]MAG-3 to [131I]OIH before Captopril was 0.81 and 0.84 after Captopril. Changes in renal function after Captopril depend on the model of renovascular hypertension and possibly the dose administered. Technetium-99m MAG-3 clearance parallels [131I]orthoiodohippurate in renovascular hypertension.

Animals↗
PubMed1989

Atrophy of left lobe of the liver associated with hepatolithiasis and cholangiocarcinoma.

A case of liver atrophy associated with hepatolithiasis and cholangiocarcinoma is presented. Intraductal calculus and left hepatic lobar atrophy were seen on both ultrasound and computerised tomography examinations. The lobar atrophy was accompanied by hypoplasia of left common hepatic artery. Cholangiocarcinoma was diagnosed on histology. There have been several reported cases of hepatolithiasis and cholangiocarcinoma. To our knowledge, there has been only one reported case of hepatolithiasis and cholangiocarcinoma with liver atrophy (Nishihara K et al 1986) but this was not angiographically demonstrated.

Adenoma, Bile Duct↗
PubMed1988

Measurement of IgG blocking antibody in human serum: comparison of ELISA with monoclonal antibody and fluorogenic substrate and Staphylococcus protein A solid-phase RIA.

We compared ELISA with mouse monoclonal antihuman gamma-chain antibody and a fluorogenic substrate with the Staphylococcus protein A solid-phase radioimmunoassay (SPRIA) in the measurement of specific IgG antibody to short ragweed pollen. Sera from 51 ragweed-allergic patients undergoing allergen immunotherapy were evaluated for ragweed-specific IgG antibodies with the same ragweed extract in the two assay systems. With optimal conditions, the ELISA and SPRIA displayed comparable positive thresholds (approximately 1 ng/ml of ragweed-specific IgG). Both assays also demonstrated consistently parallel dilution curves with 51 sera (mean interdilutional coefficient of variation [CV] less than 8.8% for ELISA and less than 8.6% for SPRIA). Reproducibility was determined by constructing precision profiles for intra- and interassay variations over the working ranges of each assay (ELISA, 0.8 to 100 ng/ml; SPRIA, 1 to 250 ng/ml). ELISA intra-assay CVs ranged from 13% near threshold to less than 5% at higher antibody concentrations; SPRIA intra-assay CVs ranged from 4.3% to 2.8%. Interassay reproducibility was somewhat better for SPRIA (4.6% to 9.6%) than for ELISA (10% to 18%). In direct comparison, 41 (80%) of the 51 sera were concordant in the two assays (r = 0.91; p less than 0.001). Although each assay result was reproducible, 10 (20%) of the sera elicited consistently discrepant results in the two assays. In eight of the 10 discordant sera, the SPRIA results were higher than ELISA, suggesting the possibility that some ragweed allergen may be better represented on the short ragweed-pollen extract agarose than on ELISA plate wells.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies↗
PubMed1988

Measurement of IgG-blocking antibodies by ELISA using monoclonal antibody and fluorogenic substrate.

An enzyme-linked immunosorbent assay (ELISA) using mouse monoclonal antihuman gamma-chain antibody and a fluorogenic substrate has been developed for quantitation of IgG-blocking antibodies in human serum. Generation of fluorescent product was linear with time to 60 min. Using optimal conditions the ELISA was sensitive to less than 1 ng/ml of specific IgG to short ragweed pollen. The assay demonstrated consistently parallel dilution curves with 51 sera (mean interdilutional coefficient of variation = 8.8%). Reproducibility was determined by constructing precision profiles for intra and interassay variation for the entire working range of the assay. Intraassay CVs ranged from a mean of 13% at threshold to less than 5% at higher antibody concentration. Interassay reproducibility similarly ranged from 18 to 10%. In this assay the effect of serum dilution on nonspecific binding was minimal and specific binding of 4-10 ng IgG antibody to the antigen-adsorbed wells was largely complete (75.8 +/- 4.8%) and highly specific (greater than 98%). This application of ELISA for ragweed IgG antibody measurement has performance specifications equal or superior to previously developed radioimmunoassay and ELISA systems.

Animals↗
PubMed1988

Use of transendothelial electrical potential difference to assess the chondroitin sulfate effect in corneal preservation media.

Corneal preservation time can be prolonged using chondroitin sulfate (CS) in preservation media and recently a great deal of attention has been focused on evaluating the effectiveness of CS. So far evaluations of the effectiveness of this and other additives have been based on determining the state of the cornea at the end of the preservation period. A more informative determination of the viability of stored corneas can be made by monitoring their physiological parameters throughout the storage period. We have accomplished this by monitoring in vitro the transendothelial electrical potential difference across deepithelialized rabbit corneas. We found that corneas stored in solutions containing basal salts, glucose and CS maintained higher transendothelial potential differences than corneas stored in the same solutions without CS, thus confirming the benefits of using CS for medium-term corneal preservation. The beneficial effects of CS were optimal at the 1% concentration, and were reduced at higher and lower concentrations.

Animals↗
PubMed1987

IgA nephropathy in Korea: a morphological and clinical study.

IgA nephropathy (IgA N) is the most common type of primary glomerulonephritis (27.5%) in South Korea and leads to renal failure in a significant number of cases. To evaluate the possible prognosticators of this disease, renal biopsy material from 142 Korean patients with IgA N was studied by light-, electron- and immunofluorescent microscopy, and a clinicopathologic correlation was made. Modified classification of Meadow et al. [1972] for Henoch-Schoenlein nephritis was adopted for the histologic grading of glomerular lesions. Twenty-three biopsies (16.2%) exhibited histologic grades IV and V lesions in association with high levels of proteinuria, serum creatinine and blood pressure and a low frequency of gross hematuria when compared to the remaining 119 biopsies with histologic grades I to III lesions. Ninety-one patients were followed for one to 6.5 years (mean, 3.4 years). Seventeen patients (18.7%) had chronic renal insufficiency, of whom eleven eventually showed endstage renal failure. More than 70% of the patients with histologic grades IV and V exhibited progressive renal disease, whereas patients with grades I to III lesions had a benign course (p less than 0.0005). These results suggest that histologic grading may be the best index to predict the present state or the subsequent progression of the lesion in IgA N.

Adolescent↗
PubMed1987

Survival rates and properties of sickle cell anemia red cells treated with nitrogen mustard.

A machine for the extracorporeal delivery of covalent anti-sickling agents has been described by Babb and coworkers and this therapeutic modality has been found feasible by others. We report here, further evaluation of nitrogen mustard (HN2), for possible use in the extracorporeal therapy of sickle cell anemia. Heparinized aliquots of whole blood from three patients with sickle cell disease were treated extra-corporeally with HN2 (0.65 mg/ml); the excess HN2 was neutralized with thiosulfate, and the blood was returned to the donor after labelling with 51Cr. HN2 produced an average 51Cr T1/2 which was 160% of control values. Fractionation of labelled red cells into different densities (ages) revealed that the main effect of HN2 was on the younger cell population which was characterized by a 51Cr T1/2 increase of 300% over the untreated blood. Further, "in vitro" studies were conducted to establish the effects on the SS red cells that could be expected from the treatment with HN2 at the concentrations used. Solubility determination (Csat) of deoxy hemoglobin S gels demonstrated that HN2 markedly inhibited the polymerization of HbS, was significantly more effective than potassium cyanate, and is among the most potent anti-sickling agents thus far reported. The viscosity of deoxygenated sickle red cells in a cone plate viscometer was markedly reduced by HN2, and hemodynamic studies using the microvasculature of an isolated rat mesoappendix demonstrated a reduction of peripheral resistance and an increase in flow rate when deoxygenated sickle cells pre-treated with HN2 were tested. At the highest concentration of HN2 (2 mg/ml), the peripheral resistance and the flow rates of deoxygenated cells attained levels found with oxygenated sickle blood. O2 affinity was partially corrected in the HN2 treated HbSS red cells. -SH reactivity of the red cell membrane was not affected by HN2. Among the added advantages of HN2 for extra-corporeal use is its rapid reaction rate, the lack of significant change of the O2 equilibrium at the concentration tested and the fact that the unreacted compound can be readily detected and neutralized. For these reasons HN2 is well suited for extra-corporeal treatment of sickle cell anemia for those patients with a severe form of the disease.

Anemia, Sickle Cell↗
PubMed1985

Mechanism of renal concentration of technetium-99m glucoheptonate.

Seventy female Sprague-Dawley rats were studied to determine the mechanism of tubular localization and the effects of commonly encountered changes in hydration and acid-base balance on renal uptake and urinary excretion of technetium-99m glucoheptonate ([99mTc]GHA). The in-vivo protein binding and protein-free plasma clearance of [99mTc]GHA also were quantitated. Twenty additional rats were studied to determine the effects of PAH competition and probenecid blockade on renal uptake of [99mTc]dimercaptosuccinic acid (DMSA) in comparison with their effects on [99mTc]GHA localization. Kidney uptake of [99mTc]GHA averaged 11.17 +/- 0.49 (s.e.)% of the injected dose in control animals. This varied slightly among groups but was significantly reduced by probenecid blockade and para-aminohippuric acid (PAH) competition to 4.08 +/- 0.55 (p less than 0.005) and 2.39 +/- 0.14 (p less than 0.005), respectively. Technetium-99m DMSA was not affected in its renal accumulation by these maneuvers. The total plasma clearance of [99mTc]GHA was lower than iodine-125(125I)iothalamate but the clearance of the protein free supernate was higher, raising a possibility of some tubular secretion. Acidification of the urine which has been shown to reduce [99mTc]DMSA uptake appeared to have no effect on [99mTc]GHA. Hepatic uptake was minimal in all groups averaging less than 1% injected dose. These data demonstrate that renal accumulation of [99mTc]GHA is blocked by probenecid and PAH suggesting that it is actively concentrated in the proximal tubule by enzyme systems similar to those involved in PAH and hippuran transport. It appears that [99mTc]GHA uptake measures a different aspect of kidney function than [99mTc]DMSA.

Acid-Base Imbalance↗
PubMed1985

Blood volume in the rat.

The organ distribution of radiopharmaceuticals in the rat is usually estimated using 7% of body weight (BW) for blood volume (BV). In spite of its important impact on the evaluation of new agents, this value has not been validated adequately. We therefore studied blood volume in 70 awake Wistar rats (100 to 400 g BW) in which red blood cell volume (RBCV) and plasma volume (PV) were measured simultaneously. Red blood cell volume was measured by in vitro RBC-tagging with Tc-99m in Sn-pyrophosphate, 0.05 microgram per ml of blood; plasma volume was measured with I-125 human serum albumin (HSA). Ten minutes after injection of the dose, 0.5 ml of blood was withdrawn from the carotid or femoral artery and duplicate samples of 0.025 ml of blood were counted after separating RBCs from plasma. Total blood volume was calculated by adding RBC volume and plasma volume. The relationship for the entire group was: BV (ml) = 0.06 X BW + 0.77 (r = 0.99, n = 70, p less than 0.001). The difference between male and female rats was not statistically significant. The use of an arbitrary value of 7% for estimation of blood volume can lead to significant errors in calculating radiopharmaceutical distribution. The use of the general formula for the blood-volume calculation described here should improve the accuracy and reliability of estimates of radiopharmaceutical distribution.

Animals↗