Characterization of a murine-human chimeric antibody with specificity for the pre-S2 surface antigen of hepatitis B virus expressed in baculovirus-infected insect cells

We have produced and characterized a murine-human chimeric antibody with specificity for the pre-S2 surface antigen of hepatitis B virus (HBV) in baculovirus-infected insect cells. Recombinant baculovirus carrying the cDNA coding for the heavy or light chain of the chimeric antibody was constructed and co-infected into insect cells. The chimeric antibody (BV-S2) expressed in the cells was purified by an affinity chromatography on Protein A-Sepharose 4B column and characterized by N-terminal amino acid sequencing, affinity determination for pre-S2 peptide, endoglycosidase digestion and Clq binding assay, which were then compared with those of the chimeric antibody H69K that has the same amino acid sequence as BV-S2, but produced from transfected murine myeloma cells. The N-linked glycosylation of the BV-S2 antibody was also analyzed by culturing the baculovirus-infected cells in the presence of tunicamycin. The results showed that the BV-S2 was secreted following correct removal of the leader peptides, contained N-linked carbohydrate at the heavy chain, and had the same binding affinity and Clq binding ability as H69K, suggesting that the BV-S2 chimeric antibody is functional and thus may be useful in the prevention of HBV infection.

A comparative study of platelets stored in polyvinyl chloride containers plasticised with butyryl trihexyl citrate or triethylhexyl trimellitate

Platelet concentrates (PCs), stored for 5 days in PL 2209, a new polyvinyl chloride (PVC) storage container plasticised with butyryl trihexyl citrate, were compared with those stored in PL 1240, a PVC platelet container plasticised with triethylhexyl trimellitate. In part 1 of the study, pooled platelet-rich plasma (PRP) was aliquoted into each type of pack and pH, pCO2, pO2, hypotonic shock response, aggregation responses, lactate, glucose and ATP concentrations, and lactate dehydrogenase and beta-thromboglobulin release were compared at days 1, 3 and 5. In part 2, 12 volunteers gave a unit of blood on two separate occasions and PCs produced by the PRP method were stored in PL 2209 or PL 1240 for 5 days before autologous reinfusion of a 111In-labelled sample. In vitro results demonstrated that PL 2209 was more gas permeable than PL 1240. In part 2 of the study, at day 5, pCO2 was 3.13 +/- 0.62 versus 5.14 +/- 0.69 (p < 0.001), whilst pO2 was not significantly different for PL 2209 versus PL 1240, respectively. pH was better maintained in PL 2209 than in PL 1240 (7.38 +/- 0.13 vs. 7.24 +/- 0.10, respectively, p < 0.01) after storage for 5 days. These results were confirmed by those from part 1. In vivo data were similar for PC stored in the two plastics with a multiple-hit recovery of 40.9 +/- 12.1% for PL 2209 and 37.4 +/- 11.3% for PL 1240, and a multiple-hit survival of 4.89 +/- 1.20 days and 5.28 +/- 2.06 days for PL 2209 and PL 1240, respectively. gamma-Camera imaging of volunteers showed similar biodistribution of radiolabelled platelets stored in each container. These results demonstrate that PL 2209 is a suitable container for storage of PCs for 5 days.

Expression and synergistic effect of three types of crystal protein genes in Bacillus thuringiensis

Bacillus thuringiensis NT0423 newly isolated from sericultural farms in Korea produces quite atypical bipyramidal crystals of a common major band of ca. 130 kDa, and has dual specificity against Lepidoptera and Diptera. To enforce the Diptera toxicity of B. thuringiensis NT0423, cryIVD and cytA genes were transformed into B. thuringiensis NT0423. The transformant B. thuringiensis PT0529 was obtained from introduction of pCG5 into B. thuringiensis NT0423 by electroporation. The expression of crystal proteins in B. thuringiensis PT0529 was characterized by SDS-PAGE and electron microscopy. The results showed that crystalline inclusions of host, CryIVD and CytA were clearly observed in B. thuringiensis PT0529. Furthermore, the toxicity of B. thuringiensis PT0529 against Diptera was highly enforced by synergistic effect.

Renal function and hemodynamic study in obese Zucker rats

OBJECTIVES

To investigate the renal function and hemodynamic changes in obesity and hyperinsulinemia which are characteristics of type II diabetes.

METHODS

Studies were carried out in two groups of female Zucker rats. Group 1 rats were obese Zucker rats with hereditary insulin resistance. Group 2 rats were lean Zucker rats and served as controls. In comparison with lean Zucker rats, obese Zucker rats exhibited hyperinsulinemia but normoglycemia. Micropuncture studies and morphologic studies were performed in these rats.

RESULTS

Functional studies showed that obese Zucker rats exhibited increases in kidney weight and GFR(obese Zucker, 1.23 +/- .07)ml/min; lean Zucker, 0.93 +/- .03ml/min). Micropuncture studies revealed that the increase in GFR in obese Zucker rats was attributable to the increases in the single nephron plasma flow rate and glomerular transcapillary hydraulic pressure. The glomerular ultrafiltration coefficient was the same in both groups. Morphologic studies revealed that the increase in GFR in obese Zucker rats was associated with an increase in glomerular volume.

CONCLUSIONS

These results suggest that obesity and hyperinsulinemia, which are the characteristics of type II diabetes, can be associated with glomerular hyperfiltration and glomerular capillary hypertension.

Calcium-activated proteolysis in rat neocortex induced by transient focal ischemia

Ischemia-induced elevation of intracellular calcium triggers a cascade of events which is considered to play a major role in neuronal death. One candidate to participate in this process is the calcium-sensitive protease, calpain. This protease is activated by calcium, and is capable of degrading critical cytoskeletal and regulatory proteins. In order to further elucidate the role of calpain in focal ischemic damage, the present study investigated the proteolysis of spectrin, a preferred substrate for calpain, in response to transient focal ischemia. Ischemia was induced by occluding reversibly both carotid arteries and the left middle cerebral artery for three hours in Sprague-Dawley rats. Western blotting techniques were used to identify and quantify the amounts of spectrin breakdown products (BDPs) in neocortical samples from the area destined for infarction, the peri-infarct area, and the contralateral hemisphere. Substantial increases in spectrin proteolysis were observed within the first few hours of ischemia in the areas that will undergo infarction. The increase in spectrin BDPs in these areas reached a plateau around the end of the 3 h ischemic period. In the peri-infarct zone, the levels of spectrin BDPs increased in a biphasic manner. A small to moderate increase was observed by the second hour of ischemia, followed by a larger increase between the 6th and 24th hours post-ischemia. The contralateral neocortex showed a significant increase in BDPs at 2 h after the initiation of ischemia. A smaller increase in BDPs was observed thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)

Functional analysis of hepatitis B virus transactivator X: implication of the leucine zipper-like region and C-terminal seven conserved amino acids in functional regions

X protein of hepatitis B virus (HBV-X) is a transactivator to a wide variety of viral and cellular transcriptional regulatory elements. Since HBV-X does not act on a common cis-regulatory element of a wide variety of regulatory elements nor does it bind to DNA directly, it has been proposed that HBV-X acts indirectly through protein-protein interactions with other transcription factors or signal transducing pathway. In order to determine the functional domain of HBV-X, we have constructed and analyzed a number of deletion and site specific mutants. Our results showed that leucine zipper-like sequences were found in the C-terminal region of HBV-X and were very important for its transactivating activity. In the analysis of deletion mutants, seven conserved and strong basic amino acids (amino acids 135-141) were essential for the transactivating activity of HBV-X.

Biological exposure indices of organic solvents for Korean workers

Biological exposure indices (BEIs) of toluene, perchloroethylene (PCE) and methyl ethyl ketone (MEK) for Korean workers were studied respectively. Exposure in workplace to organic solvents were measured by personal sampling. Blood toluene, blood PCE, urinary trichloroacetic acid and urinary MEK were determined by headspace GC. Urinary hippuric acid was determined by HPLC and corrected for creatinine. BEIs for Korean workers were calculated with the levels of the determinants corresponding to permissible exposure limits in Korea which were the same with TLV of ACGIH. Blood toluene level of 2.2 mg/l and urinary hippuric acid level of 1.7 g/g creatinine corresponded to exposure of 100 ppm toluene. Blood PCE concentration of 1.6 mg/l and urinary trichloroacetic acid concentration of 2.9 mg/l corresponded to exposure to 50 ppm PCE. Urinary MEK concentration of 1.4 mg/l corresponded to exposure to 200 ppm of MEK. In conclusion, BEIs for Korean workers determined in this study were different to ACGIH's BEI as urinary determinants were lower and blood determinants were higher than ACGIH's BEI.

Molecular cloning and characterization of an alkalophilic Bacillus sp. C125 gene homologous to Bacillus subtilis sec Y

A 1.8 kb HindIII DNA fragment containing the secY gene of alkalophilic Bacillus sp. C125 has been cloned into plasmid pUC119 using the B. subtilis secY gene as a probe. The complete nucleotide sequence of the cloned DNA indicated that it contained one complete ORF and parts of two other ORFs. The similarity of these ORFs to the sequences of the B. subtilis proteins indicated that they were the genes for ribosomal protein L15-SecY-adenylate kinase, in that order. The gene product of the alkalophilic Bacillus sp. C125 secY homologue was composed of 431 amino acids and its M(r) value has been calculated to be 47,100. The distribution of hydrophobic amino acids in the gene product suggested that the protein was a membrane integrated protein with ten transmembrane segments. The total amino acid sequence of alkalophilic Bacillus sp. C125 secY homologue showed 69.7% homology with that of B. subtilis secY. Regions of remarkably high homology (78% identity) were present in transmembrane regions, and cytoplasmic domains (73% identity) with less homologous regions present in extracellular domains (43% identity).

Microleakage of new crown and fixed partial denture luting agents

This study measured the in vitro microleakage of conventional and new FPD luting agents. Standardized preparations were made on 42 freshly extracted premolars. Facial and lingual chamfer margins were placed in enamel, mesial and distal in dentin and cementum, and castings were made in Rexillium III alloy and were then cemented with a standardized technique. Six groups of seven samples were tested, (1) polycarboxylate, (2) zinc phosphate, (3) glass ionomer, (4) Den-Mat Thin Film cement, (5) Panavia Ex, and (6) Den-Mat Thin Film cement with Tenure. The ranking of groups for stain ingress was from the greatest (1) to the least (6). A one-way analysis of variance and Tukey-Student range analysis revealed significantly similar groups, p less than 0.05:(1,2,3,4) (5,6).

Improved marginal seating of cast restorations using a silicone disclosing medium

This study was conducted to determine the effectiveness of a silicone disclosing medium, G-C Fit-Checker, as an aid in the improvement of marginal integrity. Standardized preparations were made on 42 freshly extracted premolars. Base metal alloy castings were finished externally and initially adjusted internally. The castings were placed on their respective teeth and the marginal opening was determined. They were then adjusted twice using the silicone material and remeasured. The preadjustment mean marginal opening was 92 microns and the postadjustment measurement 55 microns, yielding a mean reduction of 37 microns (SEM 3 microns) or 39%.

Porcelain-composite interface microleakage with various porcelain surface treatments

This study evaluated the effects of various porcelain surface treatments on the microleakage of the porcelain-composite interface. The experimental model isolated and evaluated only the porcelain-composite interface without the presence of a bond to tooth structure. Four types of porcelain were fired into circular porcelain tabs 1.0 mm thick by 8.5 mm in diameter. The groups of porcelain were divided into subgroups for treatment with hydrofluoric acid-etching and silane. A jig standardizing composite thickness to 0.2 mm was used to photopolymerize composite to porcelain. The margins were finished and polished with burs and disks. Samples were stored in 37 degrees C water thermocycled 1000X, placed in AgNO3 solution, embedded in epoxy, and cross-sectioned every 90 degrees for measurement of stain penetration at the composite-porcelain interface. Occasional crazing of porcelain from composite polymerization shrinkage was observed. Porcelain surface treatment significantly increased the specimens' ability to withstand water storage and thermal-cycling procedures. Porcelain surface treatment with silane alone did not reduce microleakage, but, in combination with etching, reduced microleakage significantly.

Pulmonary lymphangioleiomyomatosis in a male

Pulmonary lymphangioleiomyomatosis has been observed almost exclusively in women, usually in their reproductive years. Exacerbations with pregnancy and after hormonal manipulation have been documented, and it has been suggested that its pathogenesis is due to the influence of hormonal(estrogenic) stimulus. The clinical, roentgenographic, and histopathologic features of this case of pulmonary lymphangioleiomyomatosis in a 22-year-old male are all characteristic of those described in prior reports, except for the patient's sex. With the following case of pulmonary lymphangioleiomyomatosis in a male, we suggest the possibility of the existence of an additional pathogenetic mechanism.

Changes of lactate dehydrogenase and its isoenzyme activity in renal diseases

Analysis of the five different serum isoenzymes of lactate dehydrogenase (LDH) is of great value in the differential diagnosis of various diseases. In order to investigate the changes of serum LDH isoenzymes in several renal diseases, 44 patients with Korean hemorrhagic fever, 10 patients with chronic renal failure, 10 patients with nephrotic syndrome, and 15 healthy subjects were studied. The isoenzymes of LDH were determined by the Helena LDH isoenzyme electrophoresis procedure. LDH1 was 22.3 +/- 2.8, LDH2 29.4 +/- 5.1, LDH3 20.8 +/- 4.5, LDH4 9.0 +/- 2.7 and LDH5 8.8 +/- 3.2 mU/ml in healthy subjects. In patients in the oliguric stage of Korean hemorrhagic fever, LDH1 was 63.4 +/- 28.5, LDH2 99.7 +/- 40.7, LDH3 107.5 +/- 39.0, LDH4 41.9 +/- 32.8 and LDH5 37.2 +/- 26.3 mU/ml, while LDH1 was 23.8 +/- 11.7, LDH2 38.9 +/- 14.6, LDH3 36.0 +/- 18.7, LDH4 13.8 +/- 13.0 and LDH5 12.7 +/- 7.6 mU/ml in nonoliguric patients. In patients with chronic renal failure LDH1 was 33.2 +/- 10.8, LDH2 41.9 +/- 13.3, LDH3 27.7 +/- 8.5, LDH4 12.1 +/- 6.2 and LDH5 12.3 +/- 5.8 mU/ml. In patients with nephrotic syndrome, LDH1 was 25.1 +/- 4.3, LDH2 33.5 +/- 4.9, LDH3 23.1 +/- 6.2, LDH4 8.4 +/- 3.7 and LDH5 8.4 +/- 3.4 mU/ml. In summary, LDH3 activity was elevated in the oliguric stage of Korean hemorrhagic fever and LDH2 was elevated in chronic renal failure; those values were correlated with the BUN level.

Toxic acute renal failure and hepatitis after ingestion of raw carp bile

The raw carp bile has both nephrotoxic and hepatotoxic effects which are not well known. Recently, we studied 13 patients who had toxic acute renal failure and toxic hepatitis after ingestion of raw bile of carp in 3, grass carp in 8 and silver carp in 2 cases. The purpose of this report is to alert physicians to this very rare cause of toxic acute renal failure and hepatitis. All patients presented initially with gastrointestinal upset after eating. These symptoms were followed by oliguria in 7 patients (54%), hematuria was noted in 10 (77%) and jaundice in 8 patients (62%). Elevation of blood urea nitrogen, creatinine and transaminases lasted for about 3 weeks. The severity of the symptoms depended on the amount of bile ingested. All the patients recovered with conservative therapy and hemodialysis. Biopsy of the kidney revealed findings compatible with acute tubular necrosis similar to that produced by other nephrotoxins. Biopsy of the liver revealed findings consistent with acute toxic hepatitis. Both suggest toxic effects of carp bile as a cause of toxic acute renal failure and hepatitis.

Leptospirosis in Chonbuk Province of Korea in 1987

Leptospirosis is a zoonosis with protean clinical manifestations. Its diagnosis requires a high index of suspicion and is confirmed by isolation of the organism or, more commonly, by serologic tests. In the fall of 1987, after severe flooding, we saw 93 patients with leptospirosis, confirmed by a microagglutination test. Thirteen percent of the patients had no clinical or laboratory findings except fever and headache, but the rest had mild to severe manifestations. Jaundice, renal failure, and aseptic meningitis were not common, but pulmonary symptoms, when present, were striking. The mortality rate was 5%. The main cause of death was asphyxiation due to massive hemoptysis from pulmonary hemorrhage and acute respiratory failure.

Leptospirosis in Chonbuk Province of Korea in 1987: a study of 93 patients

Leptospirosis is a zoonosis with protean clinical manifestation. Diagnosis requires a high index of suspicion and is confirmed by isolation of the organism or, more commonly, by serologic studies. In the fall of 1987, after severe flooding, we saw 93 patients with leptospirosis, confirmed by a microagglutination test. Thirteen percent of the patients had no clinical or laboratory findings except fever and headache, but the rest had mild to severe manifestations. Jaundice, renal failure, and aseptic meningitis were not common, but pulmonary symptoms, when present, were striking. The mortality rate was 5%. The main cause of death was asphyxiation due to massive hemoptysis from pulmonary hemorrhage and acute respiratory failure.

Effects of cyclosporin A on insulin binding and action in isolated fat cells of rat

To study the effect of cyclosporin A (CsA) on glucose metabolism in peripheral insulin target cells, we studied the intraperitoneal glucose tolerance test (i.p. GTT), insulin binding, glucose transport and lipogenesis in isolated adipocytes of CsA-treated male Wistar rats. The rats were treated for 7 days with an intramuscular injection of vehicle (control group), or 5 (group I) or 50 mg/kg body weight (group II) of CsA dissolved in ethanol. The results of i.p. GTT in group II showed markedly impaired glucose tolerance with significantly decreased basal and glucose-stimulated serum insulin levels. In isolated adipocytes of CsA-treated rats, the insulin bindings were decreased by 26% in group I and 32% in group II. The maximum insulin-stimulated glucose transports were decreased by 34% in group I and 41% in group II. The maximum insulin-stimulated lipogenesis was decreased by 33% in group I and 37% in group II. There was a right shift of the dose response curves for insulin of glucose transport and lipogenesis of both CsA-treated groups. In conclusion, these results suggest that CsA produces significant functional changes of pancreatic B cells and also induces insulin resistance in adipocytes due to combined receptor and postreceptor defects in insulin action.

Red cell sodium and ionic fluxes in patients with hyper- and hypothyroidism

To investigate the status of the Na+ concentrations [Na+]i, K+ concentrations [K+]i and ionic fluxes in red cells of human subjects with abnormal thyroid function, we measured the Na(+)-K+ pump activity as well as Na(+)-K+ cotransport (CoT), Na(+)-Li+ countertransport (CTT) and Na+ passive permeability in erythrocytes of 37 normal subjects, 19 untreated hyperthyroid patients, 12 treated hyperthyroid patients and 9 hypothyroid patients with T4 replacement. The mean [Na+]i value in the untreated hyperthyroidism group was significantly higher than that in the normal subjects (p less than .05), but not significantly different from that in the treated hyperthyroidism group. The mean [Na+]i value in the hypothyroidism with T4 replacement group, however, was significantly lower than that in the normal group (p less than .01). We did not find any significant difference of [K+]i in comparing each group. It was found that the Na(+)-K+ pump activity in erythrocytes was significantly increased in untreated hyperthyroidism (mean; 23.4% above control, p less than 10(-5], but there was no significant difference in treated hyperthyroidism and hypothyroid patients with T4 replacement. The rate constant for ouabain-sensitive Na+ efflux in the hypothyroidism with T4 replacement group was markedly higher than that in normal subjects (p less than .01), but not significantly different in the untreated hyperthyroidism group. We observed a significant increase of the Na+ CoT value in the patients with untreated hyperthyroidism as compared with that of the normal subjects (p less than .05), but there was no significant difference in the patients treated for hyperthyroidism and the hypothyroidism with T4 replacement group. However, the rate constant for Na(+)-CoT in the patients with hypothyroidism with T4 replacement was significantly higher than that in normal subjects (p less than .05). We observed a marked decrease of Na(+)-Li+CTT value in the patients with untreated hyperthyroidism versus that in the normal group (p less than .01). Passive Na+ permeability in the patients with untreated hyperthyroidism was markedly increased (p less than .05), and was markedly decreased in the patients with hypothyroidism with T4 replacement compared to normal subjects (p less than .01). It can be concluded from these studies that an increase in Na(+)-K+ pump activity in the patients untreated for hyperthyroidism might then be regarded as a secondary adaptive cellular response to higher [Na+]i values due to enhanced passive Na+ permeability, rather than a direct effect of the thyroid hormone.

Nephrotic syndrome associated with renal vein thrombosis--a report of 3 cases

The coexistence of nephrotic syndrome and renal vein thrombosis has been of medical interest since Rayer’s description in 1840. Renal vein thrombosis has been underdiagnosed because of its variable clinical and radiological findings but it becomes a more frequently recognizable clinical entity since diagnosis can be easily established by modern angiographic techniques. Generally it has been believed that renal vein thrombosis may cause nephrotic syndrome. But recent articles strongly suggest that renal vein thrombosis is a complication of the nephrotic syndrome rather than a cause. We report three cases of nephrotic syndrome associated with renal vein thrombosis.

Hyperkalemia by beta-fluoroethylacetate: a report of 2 cases

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2,3-diphosphoglyceric acid changes in uremia and during hemodialysis

The present study is an investigation of the mechanism of changes in erythrocyte 2,3-diphosphoglyceric acid (2,3-DPG) in patients with chronic renal failure during hemodialysis. The study was conducted on 7 Korean and 6 American patients on maintenance hemodialysis. The plasma pH of Korean patients was 7.31±0.02 before hemodialysis and 7.40±0.04 after hemodialysis (p<0.001). The pH of erythrocyte also increased from 7.13±0.02 to 7.20±0.03. The concentration of hemoglobin 2,3-DPG in Korean patients was 10.86±2.89 μmol/g before hemodialysis and 19.93±2.89 μmol/g after hemodialysis (p<0.001). Similar results were obtained in American patients. Hemoglobin 2,3-DPG was 12.54±2.53 and 18.76±6.73 μmol/g before and after dialysis respectively. Despite the presence of substantial anemia, hemoglobin 2,3-DPG prior to hemodialysis was significantly lower than the values obtained in the normal controls (17.45±4.3 μmol/g). The blood glucose increased from 93.3±8.5 mg/dl before dialysis to 117.1±6.1 mg/dl after hemodialysis in Korean patients but no significant change was detected in American patients. The increased blood glucose with hemodialysis observed in Korean patients was probably attributable to the lower baseline glucose concentration and the gain of glucose from dialysate, which had a glucose concentration of 186±34.1 mg/dl. The results suggest that the increase in 2,3-DPG with hemodialysis is probably caused by an increase of pH and an increased glucose utilization.