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Biomedical subjects

J Kobayashi

Publications and source records attributed to J Kobayashi.

At least 19 recordsLinked to original sources
PubMed1996

DNA replication-related elements cooperate to enhance promoter activity of the drosophila DNA polymerase alpha 73-kDa subunit gene.

An analysis was carried out on the promoter region of the Drosophila DNA polymerase alpha 73-kDa subunit gene and the factor(s) activating the promoter. Transcription initiation sites were newly identified in the region downstream of the previously determined sites. Full promoter activity resided within the region from -285 to +129 base pairs with respect to the newly determined major site. Within this region, we found three sequences identical or similar to the DNA replication-related element (DRE), 5'-TATCGATA, which is known as a common promoter-activating element for the Drosophila DNA polymerase alpha 180-kDa subunit gene and the proliferating cell nuclear antigen gene. These sites were located at positions -77 to -70 (DREalpha-I), -44 to -37 (DREalpha-II), and +3 to +10 (DREalpha-III). Footprinting analysis using the recombinant DRE-binding factor (DREF) or Kc cell nuclear extract demonstrated that DREF can bind to all three DRE-related sites. Introduction of mutation in even one of the three DRE-related sequences caused extensive reductions of the promoter activity and also the DREF-binding activity of the promoter-containing fragment. The results indicate that the three DREF-binding sites cooperate to enhance promoter activity of the DNA polymerase alpha 73-kDa subunit gene.

Animals↗
PubMed1996

Hepatic lipase gene therapy in hepatic lipase-deficient mice. Adenovirus-mediated replacement of a lipolytic enzyme to the vascular endothelium.

Hepatic lipase (HL) is an endothelial-bound lipolytic enzyme which functions as a phospholipase as well as a triacylglycerol hydrolase and is necessary for the metabolism of IDL and HDL. To evaluate the feasibility of replacing an enzyme whose in vivo physiologic function depends on its localization on the vascular endothelium, we have infused recombinant replication-deficient adenovirus vectors expressing either human HL (HL-rAdV; n = 7) or luciferase cDNA (Lucif-rAdV; n = 4) into HL-deficient mice with pretreatment plasma cholesterol, phospholipid, and HDL cholesterol values of 176 +/- 9, 314 +/- 12, and 129 +/- 9, respectively. After infusion of HL-rAdV, HL could be detected in the postheparin plasma of HL-deficient mice by immunoblotting and postheparin plasma HL activities were 25,700 +/- 4,810 and 1,510 +/- 688 nmol/min/ml on days 5 and 15, respectively. Unlike the mouse HL, 97% of the newly synthesized human HL was heparin releasable, indicating that the human enzyme was virtually totally bound to the mouse vascular endothelium. Infusion of HL-rAdV in HL-deficient mice was associated with a 50-80% decrease in total cholesterol, triglyceride, phospholipids, cholesteryl ester, and HDL cholesterol (P < 0.001) as well as normalization of the plasma fast protein liquid chromatography lipoprotein profile by day 8. These studies demonstrate successful expression and delivery of a lipolytic enzyme to the vascular endothelium for ultimate correction of the HL gene defect in HL-deficient mice and indicate that recombinant adenovirus vectors may be useful in the replacement of endothelial-bound lipolytic enzymes in human lipolytic deficiency states.

Adenoviridae↗
PubMed1996

Maze procedure and anomalous coronary artery repair.

A 60-year-old woman has anomalous origin of the left coronary artery from the pulmonary artery, mitral regurgitation with left ventricular dysfunction, and atrial fibrillation. We performed mitral valve annuloplasty, maze procedure, and intrapulmonary tunnel repair of anomalous origin of the left coronary artery. The patient regained normal sinus rhythm and showed improved left ventricular function and no mitral regurgitation.

Cardiac Surgical Procedures↗
PubMed1996

Pentoxifylline in flush solution improves early lung allograft function.

BACKGROUND: Postischemic ischemia reperfusion injury is a frequent and unpredictable problem in clinical lung transplantation. Pentoxifylline (PTX) has a number of effects that could decrease reperfusion injury: reduced neutrophil adhesion to endothelium, decreased production of tumor necrosis factor, decreased platelet aggregation, and increased production of vasodilatory prostaglandins by vascular endothelium. We have demonstrated previously that PTX administered before storage and again during reperfusion reduced lung reperfusion injury. The purpose of the present study was to determine whether these observations were storage or reperfusion effects. METHODS: Fourteen canine left lung allotransplantations were performed. Donor lungs were flushed with modified Euro-Collins solution and stored for 24 hours at 1 degree C. Immediately after transplantation, the contralateral right main pulmonary artery and bronchus were ligated to assess isolated allograft function. Hemodynamic indices and arterial blood gas analysis (inspired oxygen fraction 1.0) were assessed for 6 hours before sacrifice. Allograft myeloperoxidase activity was assessed. Bronchoalveolar lavage fluid was obtained from the allograft middle lobe for neutrophil counts. The animals were divided into three groups based on the timing of PTX administration. Group 1 (n = 5) animals received no PTX. Group 2 (n = 4) animals received PTX (20 mg/kg) just before reperfusion as well as continuous infusion (0.1 mg x kg-1 x min-1) during the assessment period. In group 3 (n = 5), donor lungs received PTX (200mg/L) in the flush solution only. RESULTS: Superior gas exchange was noted in the lungs receiving PTX only in the flush solution (group 3). Myeloperoxidase activity in group-3 allografts was significantly reduced. In addition, protein levels and neutrophil counts in the bronchoalveolar lavage fluid were significantly reduced in group-3 allografts. CONCLUSIONS: Pentoxifylline ameliorates lung allograft reperfusion injury when administered in the flush solution. Our data suggest that PTX will prevent graft endothelial dysfunction during 24-hour cold ischemic storage and consequently will prevent neutrophil activation and migration into lung tissue.

Analysis of Variance↗
PubMed1996

Serum KL-6 for the evaluation of active pneumonitis in pulmonary sarcoidosis.

KL-6, a mucinous high-molecular weight glycoprotein, expressed on type II pneumonocytes, is elevated in the serum of patients with active interstitial pneumonia. Forty-seven patients with histologically confirmed sarcoidosis were analyzed by chest radiography, CT, 67Ga scintigraphy, BAL fluid (BALF), and serum KL-6. Serum KL-6 level was significantly elevated in radiographic type II (945 +/- 725 U/mL; n = 13; p < 0.01) and type III (1,179 +/- 1,320 U/mL; n = 9; p < 0.01), as compared with type 0 (333 +/- 173 U/mL; n = 10) and type I (430 +/- 225 U/mL; n = 15). Serum KL-6 level was significantly elevated in patients with CT findings of irregular small opacities, ground-glass opacities, and thickened bronchovascular bundle (p < 0.01), as compared to those without these findings. Serum KL-6 level was significantly elevated in patients with positive pulmonary accumulation in 67Ga scintigraphy (1,108 +/- 1,044; n = 20; p < 0.001) as compared to those without accumulation (390 +/- 206; n = 27). Serum KL-6 level was elevated in patients with a higher CD4+/CD8+ ratio (> or =3) in BALF, as compared to those with lower ratios. These results suggest that serum KL-6 is a useful marker of sarcoidosis activity.

Adolescent↗
PubMed1996

Cloning of mRNA sequences for two antibacterial peptides in a hemipteran insect, Riptortus clavatus.

Escherichia coli injection rapidly induced bactericidal activity in the hemolymph of a hemipteran insect, Riptortus clavatus. This activity reached its maximum at 9 hr after injection and thereafter declined slowly. Two types of cDNA clones involved in this response were isolated by differential screening. The predominant type encoded for an open reading frame of 678 amino acids, which consisted of fourteen tandem repeats. Each repeat was rich in charged residues and had a proline-rich region which had striking sequence similarities to proline-rich antibacterial peptides from other insect species, indicating these clones encode a multipeptide precursor of antibacterial peptides. The other type encoded for a glycine-rich peptide similar to a known antibacterial peptide as well. Northern blot analyses revealed rapid induction of mRNAs corresponding to these clones after the injection. To our knowledge, this is the first report on the mRNA sequences of antibacterial peptides of hemimetabolous insects, and the second report on the occurrence of multipeptide precursor structure in insect antibacterial peptides.

Animals↗
PubMed1996

[Valvular surgery in the patients more than 70 years old].

One hundred twenty-eight valvular surgeries in patients over 70-year-old were reviewed (AVR:58, MVR:38, AVR and MVR: 11, mitral valvuloplasty (MVP): 11, AVR + MVP:11, mitral valvuloplasty (MVP): 11, AVR + MVP: 8, others: 2). Concomitant CABG was performed in 7, Maze in 6, TVR in 5 and Bentall in 3 cases. Early deaths occurred in 17 patients (13%). The early mortality was 5% in AVR, 21% MVR, 18% in AVR and MVR, 0% in MVP and 38% in AVR and MVP. Late death occurred in 16 patients. Forty-three percent of the late deaths were cardiac death. The actuarial survival at 10 years was around 50% in all groups. In the aortic position, a mechanical valve was implanted in 47 cases and a bioprosthetic valve was implanted in 33 cases. In the mitral position, the mechanical valve was implanted in 37 cases and the bioprosthetic valve was implanted in 12 cases. The event free rate after AVR at 10 years was 37% in patients with the mechanical valve (3 cerebral hemorrhage, 2 PVE, 1 thromboembolism and 1 sudden death) and 46% in patients with the bioprosthetic valve (2 PVE and 1 primary tissue failure). The event free rate after MVR at 10 years was 84% in patients with mechanical valves (1 perivalvular leak, 1 PVE and 1 sudden death) and 75% in patients with bioprosthetic valves (1 PVE and 1 sudden death). Between mechanical valve group and bioprosthesis group, no statistically significance was found in the event free curve after AVR nor MVR. There was no valve related event after MVP. Considering the better durability of bioprostheses in the aortic position than in the mitral position, the presence of atrial fibrillation and necessity of warfarin anticoagulation, we conclude that a choice of a bioprosthetic valve could be acceptable in the aortic position, but may not be recommended in the mitral position.

Aged↗
PubMed1996

[Anticoagulant related hemorrhage and thromboembolism after valvular surgery].

We reviewed anticoagulant related hemorrhage (ACRH) and thromboembolism (TE) in 84 patients after valvular surgery. There were 45 females and 39 males with a mean age of 51.8 years (range 30.5-71.2 years), who underwent valvuloplasty in 14, bioprosthetic valve replacements in 17, mechanical valve replacements in 13. A mean period from the operation to the event were 2.7 years (range 0.01-12.3 years). There were 25 ACRH events after one valvuloplasty, 4 bioprosthetic valve replacements, 20 mechanical valve replacements. About half of them, the prothrombin time were less than 25%, which was considered the effect of warfarin is high, and 8% of them had infective endocarditis (IE) previously. There were 59 TE events after 13 valvuloplasties, 13 bioprosthetic valve replacements, 33 mechanical valve replacements. In the patients with atrial fibrillation, TE occurred irrespective of operative procedures. And in the patients with mechanical valve, severely impaired left ventricular function and past history of IE, thrombi of left ventricule were caused of TE. It was suggested that past history of IE was a risk factor ACRH and TE, and severely depressed left ventricular function and atrial fibrillation were for TE.

Adult↗
PubMed1996

The mode of rabbit platelet shape change and aggregation induced by theonezolide-A, a novel polyketide macrolide, isolated from the Okinawan marine sponge Theonella sp.

Theonezolide-A (TZ-A), a novel polyketide macrolide, isolated from the Okinawan marine sponge Theonella sp., caused a marked platelet shape change at low concentrations (0.2-0.6 microM). Increasing concentrations of TZ-A to 6 microM or more caused shape change followed by a small but sustained aggregation. In a Ca(2+)-free solution, TZ-A-induced aggregation was markedly inhibited, although the marked shape change was still observed. Aggregation stimulated by TZ-A increased in a linear fashion with increasing Ca2+ concentrations from 0.1 to 3.0 mM. Furthermore TZ-A markedly enhanced 45Ca2+ uptake into platelets. Aggregation induced by TZ-A was inhibited by Arg-Gly-Asp-Ser, an inhibitor of fibrinogen binding to glycoprotein IIb-IIIa, H-7 and staurosporine, protein kinase C inhibitors, or genistein and tyrphostin A23, protein tyrosine kinase inhibitors, whereas shape change was blocked by genistein and tyrphostin A23. H-7 or staurosporine did not affect the TZ-A-induced shape change. These results suggest that TZ-A-induced platelet shape change is not dependent on external Ca2+, whereas TZ-A-induced aggregation is caused by an increase in Ca2+ permeability of the plasma membrane. It is also suggested that both aggregation and shape change induced by TZ-A are associated with protein phosphorylation by protein kinase C and tyrosine kinase.

Adenosine Diphosphate↗
PubMed1996

[Use of the the ED046 kit to analyze serum KL-6 in patients with pneumonitis].

KL-6 is a mucinous glycoprotein expressed on Type 2 pneumonocytes, and serum levels of KL-6 are reported to be abnormally high in patients with interstitial pneumonia. A new assay kit for serum KL-6 (ED046) was used in the evaluation of patients with pneumonitis. To clarify whether KL-6 is a useful marker of pneumonitis activity, 649 subjects were studied, including 185 healthy controls, 187 patients with 3 types of interstitial lung diseases, and 277 patients with 4 types of non-interstitial lung diseases. The serum KL-6 level was significantly higher in the patients with pneumonitis (1285 +/- 1196 U/ml) than in the patients without pneumonitis (307 +/- 232 U/ml). The KL-6 level was also significantly higher in patients with clinically active pneumonitis (1708 +/- 1338 U/ml) than in those with inactive pneumonitis (820 +/- 796 U/ml) (p < 0.0001). Serum KL-6 levels correlated significantly with serum c-reactive protein, lactic dehydrogenase, and PaO2 values. These results suggest that the ED046 assay is useful for measuring KL-6 as a marker of pneumonitis activity.

Adult↗
PubMed1995

Structure-activity relationship of bromoeudistomin D, a powerful Ca2+ releaser in skeletal muscle sarcoplasmic reticulum.

Bromoeudistomin D and 9-methyl-7-bromoeudistomin D which have a beta-carboline skeleton are powerful Ca2+ releasers from skeletal muscle sarcoplasmic reticulum exhibiting caffeine-like properties. We examined the effects of bromoeudistomin D analogues on Ca(2+)-induced Ca2+ release from skeletal muscle sarcoplasmic reticulum. Among bromoeudistomin D analogues, the Ca(2+)-releasing activities of carboline derivatives were higher than those of carbazole derivatives, suggesting that a carboline skeleton is significantly important for the manifestation of Ca(2+)-releasing activity and Ca2+ sensitivity of Ca(2+)-induced Ca2+ release. On the contrary, the analogues which have a carbazole skeleton and bromine at C-6 inhibit both Ca(2+)- and caffeine-induced Ca2+ release. 9-Methyl-substitution of the analogue elevated its Ca(2+)-releasing activity. Moreover, there is a close correlation between the enhancement of [3H]ryanodine binding to sarcoplasmic reticulum by the analogues and the activation of Ca2+ release by them. Bromoudistomin D analogues may provide valuable information about the structure-function relationship of the ryanodine receptor/Ca2+ release channels in skeletal muscle sarcoplasmic reticulum.

Animals↗
PubMed1995

Reduced dimerization of lipoprotein lipase in post-heparin plasma of a patient with hyperchylomicronemia.

As in post-heparin plasma of control subjects, post-heparin plasma of a patient with hyperchylomicronemia contained lipoprotein lipase (LPL) subunits with M(r) = 57,000. But although the amount of LPL was the same as in post-heparin plasma of controls, no LPL activity was detectable. Nearly all the LPL in post-heparin plasma of controls bound to heparin-Sepharose and this LPL bound was mainly eluted with 1.5 M NaCl in parallel with the activity. In post-heparin plasma of the patient, 58% of the LPL subunits did not bind to heparin-Sepharose and 23% was eluted with 0.6 M NaCl. Studies by sucrose density gradient centrifugation showed that almost all the LPL in post-heparin plasma of controls was recovered in the peak with a sedimentation coefficient of 6.8 S, corresponding to the position of a dimeric form of LPL, in parallel with the activity; little LPL was recovered in the peak with a sedimentation coefficient of 4.0 S, corresponding to the position of a monomeric form of LPL. In post-heparin plasma of the patient, 35% of the LPL subunits was recovered in fractions with larger sedimentation coefficients at the bottom of the centrifuge tube, indicating the presence of an aggregated form(s) of LPL; the amount of the monomeric form of LPL was increased, while that of the dimeric form was decreased. Thus, defect of LPL activity in post-heparin plasma of the patient with hyperchylomicronemia could result from reduced dimerization of LPL subunits.

Adolescent↗