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Biomedical subjects

N Kobayashi

Publications and source records attributed to N Kobayashi.

At least 19 recordsLinked to original sources
PubMed1992

The Soret magnetic circular dichroism of ferric high-spin myoglobins. A probe for the distal histidine residue.

To find a simple criterion for the presence of the distal (E7) histidine residue in myoglobins and hemoglobins, the Soret magnetic-circular-dichroic spectra were examined for ferric metmyoglobins from various species. A distinct and symmetric dispersion-type curve was obtained for myoglobins containing the distal histidine, whereas a relatively weak and unsymmetric pattern was observed for myoglobins lacking this residue, such as those from three kinds of gastropodic sea molluscs, a shark and the African elephant. The magnetic-circular-dichroic spectra obtained would thus be a direct reflection of the presence or absence of a water molecule at the sixth coordinate position of the heme iron(III), this axial water ligand being stabilized by hydrogen-bond formation to the distal histidine residue. On the basis of these Soret magnetic-circular-dichroic signals, we also examined the structure of a protozoan myoglobin (or a monomeric hemoglobin) from Paramecium caudatum of particular interest for the evolution of these proteins from protozoa to higher animals.

Animals↗
PubMed1992

Differences in the enzymatic nature and the sugar-chain structure of gamma-glutamyl transferase between normal and carcinomatous human kidney and prostate.

The enzymatic and immunological nature, and the sugar chain structure, of gamma-glutamyl transferase (GGT) purified from tissues of benign prostatic hypertrophy (BPH), prostatic carcinoma (PCa) and renal cell carcinoma (RCa), were compared with those of the normal prostate (NP) and kidney (NK). The specific activities of GGTs in NP, NK, BPH, PCa and RCa were 78.9, 22.5, 105, 92.5 and 52.5 mU/mg protein, respectively. The molecular masses of GGTs from BPH, PCa and RCa were 72 kDa, 78 and 108 kDa, and 79 and 105 kDa, respectively. The Michaelis constants (Km), optimum pHs and the inhibition of GGT activities by several chemical compounds, revealed that the GGT from BPH, PCa and RCa was similar to that of normal GGT. Immunologically, the IgG fraction against anti-human seminal plasma GGT fused to the all of the GGTs tested. The sugar chain heterogeneities of the various GGTs, detected by the serial-lectin affinity technique, differed from one another. The sugar chain of GGT from BPH resembled the sugar chain from NP. On the contrary, the sugar chains of GGTs from PCa and RCa were markedly different from those from normal tissues. In the GGT from PCa, multi-antennary complex type sugar chains were more increased than the enzyme of NP. In general, as previously reported, the sugar chains of GGTs from carcinomatous tissues of prostate and kidney had an increased content of bisecting GlcNAc (beta 1-->4) containing complex type sugar chains. Moreover, the reductions of the biantennary complex type sugar chain with fucose linkage and the hybrid type sugar chain were obvious in the GGT from carcinomatous tissues of the prostate and kidney.

Adult↗
PubMed1992

1H NMR study on the conformation of bacitracin A in aqueous solution.

The conformation of bacitracin A, a widely used cyclic dodecapeptide antibiotic in aqueous solution, has been investigated using 500 MHz 1H NMR and molecular modeling. Findings revealed that a region (residues 1-6) is folded over the cyclic ring, resulting in metal coordination sites, a thiazoline ring, and Glu4 and His10 being proximate to each other.

Amino Acid Sequence↗
PubMed1992

Total vascular exclusion for hepatic resection in cirrhotic patients. Application of venovenous bypass.

Hepatic vascular exclusion with double venovenous bypass using a centrifugal force pump was used in major hepatic resections in eight patients with hepatocellular carcinoma combined with cirrhosis, and results were compared with those in four patients with hepatocellular carcinoma without cirrhosis and eight with metastatic tumors without cirrhosis among 521 patients undergoing liver resection. Concomitant resection of the retrohepatic inferior vena cava was performed in three of eight patients with cirrhosis and five of 12 patients without cirrhosis. All patients, except one with cirrhosis, tolerated major resection without any hemodynamic impairment, which is often observed in hepatic vascular exclusion without venovenous bypass. One patient, whose complete inflow occlusion period was 70 minutes, died of liver failure. In this patient, the recovery of the arterial ketone body ratio above 1.0 was delayed until 3 days after recirculation, whereas the ratio in the others recovered promptly. Postoperative complications such as increased bilirubin level, pleural effusion, and gastrointestinal tract bleeding were observed in seven of eight patients with cirrhosis compared with six of 12 without cirrhosis. Hepatic vascular exclusion is feasible even in cirrhotics as long as it is applied with venovenous bypass and is kept within the time limit of 60 minutes.

Adult↗
PubMed1992

Structural relationships between the endothelial actin system and the underlying elastic layer in the distal interlobular artery of the rat kidney.

The structure of the intracellular actin filaments and the extracellular matrices was studied in the distal interlobular arteries in the rat kidney, employing three different morphological techniques, including rhodamine-phalloidin staining of cryosections, resorcin-fuchsin staining of paraffin sections, and a cold dehydration procedure for electron microscopy. The endothelial cells possess longitudinally running stress fibers. The inner elastic layer is composed of meshworks of elastic fibers encompassing numerous pores. The smooth muscle cells containing abundant actin filaments are arranged circumferentially around the vascular axis. The endothelial stress fibers are found mainly in the basal half of the endothelial cells, and anchor onto the basal cell membranes. The elastic meshworks send off longitudinal branch fibers to contact the endothelial cell membranes at the anchoring sites of stress fibers. In addition circumferential branches run toward the smooth muscle cells. The functional significance of the intracellular contractile apparatus and the extracellular tensile component in small arteries was discussed.

Actins↗
PubMed1992

Traumatic cervical syringomyelia related to birth injury.

A rare case of cervical syringomyelia related to breech delivery is reported. The initial diagnosis was bilateral brachial plexus palsy due to birth injury, which was revealed by magnetic resonance imaging (MRI) to be traumatic syringomyelia. The usefulness of MRI in the early diagnosis of cervical cord birth injury, especially in differentiating between brachial plexus palsy due to birth injury and spinal cord trauma due to birth injury in infancy, is emphasized.

Birth Injuries↗
PubMed1992

Induction and repair of UVB-induced cyclobutane pyrimidine dimers and (6-4) photoproducts in organ-cultured normal human skin.

To examine the induction and repair of UV-induced DNA damage, indirect immunofluorescence was performed on UVB-irradiated organ-cultured normal human skin using monoclonal antibodies specific for either cyclobutane pyrimidine dimers or (6-4) photoproducts. Nuclear immunofluorescence of cyclobutane pyrimidine dimers and (6-4) photoproducts were observed in a dose-dependent manner after UVB irradiation. The intensity of nuclear immunofluorescence of the upper epidermal layers was stronger and clearer than that of the lower epidermal layers. DNA repair time-course studies showed that both types of DNA damage could be repaired within 24 h after UVB irradiation.

Cyclobutanes↗
PubMed1992

Obstructive jaundice caused by polypoid inflammatory granuloma in a consanguineous case.

Granuloma in the biliary system is a rare condition. The majority of the reported cases concern postsurgical granuloma. We note a patient with obstructive jaundice due to inflammatory granuloma in whom a filling defect was found at the bifurcation of the common hepatic duct by preoperative cholangiography. There have been no reported cases with similar findings. In addition to these features, this case was further characterized by consanguinity, repeated spontaneous abortions, and severe vascular lesions found in many organs that suggested the presence of a hereditary defect.

Bile Duct Diseases↗
PubMed1992

Production and specificity of antisera raised against 25-hydroxyvitamin D3-[C-3]-bovine serum albumin conjugates.

In order to obtain specific antisera for use in the enzyme immunoassay of 25-hydroxyvitamin D3, three hapten-carrier conjugates having different lengths of bridges at the C-3 position were prepared from 25-hydroxyvitamin D3 by coupling with bovine serum albumin using the active ester method. The specificity of anti-25-hydroxyvitamin D3 antisera elicited in rabbits was tested by a cross-reaction study with closely related secosterols and by measuring the plasma levels of 25-hydroxyvitamin D3 by means of radioimmunoassay using tritium-labeled antigen. The results indicated that the specificity of the antisera obtained is higher than that of vitamin D-binding protein, and that some of these antisera are suitable for enzyme immunoassay.

Animals↗
PubMed1992

Sequence variation in Japanese HLA-DRw8 specificity.

There are four DRw8 haplotypes with different DQ alleles in Japanese: DRw8-DQw6 (w1), DRw8-DQw4, DRw8-DQw8(w3), and DRw8-DQw7 (w3). We previously reported the nucleotide sequence of DRB1 gene of DRw8-DQw6(w1) and it was named DRB1*08032. The nucleotide sequences of the other DRw8 DRB1 alleles and their correspondence to internationally recognized DRw8 subspecificities were still unclear. We have cloned these DRB1 genes and determined the nucleotide sequences. The comparison of the sequences with the published sequences revealed that the differences were occurred at two amino acid positions, and these four haplotypes are classified in two groups: (a) DRw8-DQw6(w1) and DRw8-DQw7(w3), and (b) DRw8-DQw4 and DRw8-DQw8(w3). The DRB1 molecules of DRw8-DQw6(w1) and DRw8-DQw7(w3) have Ser57 and Ile67, and those of DRw8-DQw4 and DRw8-DQw8(w3) have Asp57 and Phe67. The former has the same sequence as that of DRB1*08032, and the latter is same as that of DRB1*0802. The classification corresponds to the serologic subtyping, which divides DRw8 into DR8.1 and DR8.2, reported in the 10th Japan HLA Workshop.

Alleles↗
PubMed1992

Large-scale culture system of human CD4+ helper/killer T cells for the application to adoptive tumour immunotherapy.

A simple method for the rapid expansion of human CD4+ T cells with both helper and killer functions was established. CD4+ T cells separated from peripheral blood mononuclear cells using immunomagnetic beads were stimulated with immobilised OKT-3 monoclonal antibody (mAb) plus recombinant interleukin 2 (rIL-2) in 96 well culture plates. After 6 day-culture, the CD4+ T cells were restimulated by immobilised OKT-3 mAb for an additional 24 h, then inoculated into concentrated rotary-tissue culture bag and cultured for further 9 days. This procedure yielded a 3000-fold increase in cell number (about 3-5 x 10(9) per bag). Most of the cells (over 96%) continued to express CD4+ antigen and retained their capacity to produce IL-2. The activated CD4+ T cells showed marked cytotoxicity against Fc receptor positive tumour cells in the presence of OKT-3 mAb. Moreover, we succeeded in a specific targeting of the expanded CD4+ helper/killer T cells to c-erb B-2 positive tumour cells by means of anti-CD3 x anti-c-erb B-2 bispecific antibody. These results suggested that our established simple system will be available for the expansion of large number of CD4+ helper/killer T cells which may provide an efficient strategy for adoptive tumour immunotherapy.

Antibodies, Monoclonal↗
PubMed1992

Alterations in endothelium-associated proteins and serum thyroid hormone concentrations in anorexia nervosa.

Plasma concentrations of endothelium-associated proteins (EAP) (plasma fibronectin (PFN), angiotensin-converting enzyme, factor VIII-related antigen (F VIII-R:Ag)) and tissue plasminogen activator and serum thyroid hormone concentrations were studied in nine patients with anorexia nervosa (AN), before and after weight gain. Before weight gain (-35.9 (SE 2.3)% of standard body-weight) PFN was significantly reduced and F VIII-R:Ag was significantly increased in AN patients compared with the concentrations in control subjects (211.5 (SE 14.9) v. 274.7 (SE 16.6) micrograms/ml, P < 0.05; 129.2 (SE 14.1) v. 88.2 (SE 9.7) %, P < 0.05 respectively). Serum triiodothyronine (T3) and free T3 levels were also significantly lower before weight gain in AN patients (0.85 (SE 0.07) v. 1.53 (SE 0.08) nmol/l, P < 0.001; 2.57 (SE 0.23) v. 5.31 (SE 0.34) pmol/l, P < 0.001 respectively), although serum thyroxine (T4), free T4, and thyrotropin concentrations were within the normal range throughout the study periods. Following weight gain, PFN and F VIII-R:Ag concentrations normalized as did the thyroid hormone levels. The incremental changes in PFN levels correlated significantly with those in serum thyroid hormone concentrations (T3, r 0.79, P < 0.01; free T3, r 0.84, P < 0.01). These findings suggest that PFN levels may be directly related to serum T3 concentrations in AN patients.

Adult↗
PubMed1992

A mixture of nucleosides and a nucleotide alters hepatic energy metabolism 24 hours after hepatectomy in rabbits.

The effect of administering a nucleoside-nucleotide mixture on hepatic energy metabolism was evaluated at 24 h after hepatectomy in rabbits that had had 70% of their livers removed. After hepatectomy, animals were administered continuous intravenous infusion of 2 mL/(kg body wt-h) of 9 g/L NaCl (Group S), 5.99 mmol/L nucleoside-nucleotide mixture (Group N1) or 11.98 mmol/L nucleoside-nucleotide mixture (Group N2). At 24 h after hepatectomy, the hepatic adenylate energy charge in Group S (0.83 +/- 0.01, mean +/- SEM) was significantly lower than that before hepatectomy (0.90 +/- 0.01). By contrast, the values in Groups N1 and N2 after hepatectomy (0.74 +/- 0.04 and 0.73 +/- 0.04, respectively) were significantly lower than that in Group S. The hepatic mitochondrial phosphorylation rate before hepatectomy was 46.40 +/- 4.88 nmol ATP/(mg mitochondrial protein-min). After hepatectomy, significantly greater values were observed in Groups N1 and N2 (69.53 +/- 7.20 and 63.31 +/- 6.11, respectively), yet those values were less than observed in Group S (109.14 +/- 4.80). These results suggest that the nucleoside-nucleotide mixture suppressed the enhancement of hepatic mitochondrial phosphorylative activity at a time when hepatic adenylate energy charge is compromised. Such enhancement is needed to compensate for the increased energy expenditure due to surgical intervention.

Adenosine Diphosphate↗
PubMed1992

An appraisal of pediatric liver transplantation from living relatives. Initial clinical experiences in 20 pediatric liver transplantations from living relatives as donors.

The authors performed 20 liver transplantations from living related donors between June 1990 and July 1991. The 20 pediatric patients (14 biliary atresia, two Budd-Chiari syndrome, one liver cirrhosis after hepatitis C viral infection (HCV hepatitis), 1 progressive intrahepatic cholestasis, 1 liver cirrhosis, 1 protoporphyria) were transplanted with 11 left lobes, eight left lateral segments, and one right lobe. The choice of donors was restricted to the parents of the recipients. The immunosuppressive treatment consisted of FK 506 and steroids. Seventeen recipients are alive, 15 of whom are well and at home. Two recipients, who underwent emergency transplantation, died of postoperative complications. Another recipient died of accidental asphyxia at 6 months after the transplantation. All 20 donors had uneventful postoperative courses and were able to resume their normal social lives. The arterial ketone body ratio (AKBR) increased to above 1.0 within 2 days after the transplantation in all cases. Relatively mild rejection episodes were encountered in only two cases transplanted with ABO-compatible grafts, and these were treated successfully with steroids and FK 506.

Adolescent↗
PubMed1992

BUN/Cr ratio as an index of gastrointestinal bleeding mass in children.

Determining the site and severity of blood loss is important in the management of children with gastrointestinal (GI) bleeding. Blood urea nitrogen (BUN) and serum creatinine (Cr) were measured on the day of hospitalization and the ratio of BUN/Cr was calculated in 11 children with 16 episodes of upper GI bleeding and 49 with lower GI bleeding. There was a significant difference between the two GI bleeding groups with regard to BUN/Cr ratio (p less than 0.001). When the ratio was 30 or above, the specificity of upper GI bleeding was 98% with a sensitivity of 68.8%. A linear relationship was found between the BUN/Cr ratio and delta Hb (delta Hb = 0.08 x BUN/Cr +/- 0.8 g/dl) for bleeding originating from the upper GI tract. This study confirms that measurement of the BUN/Cr ratio is useful for localizing the source of bleeding to the upper GI tract and also demonstrates its usefulness as an estimation of the severity of blood loss from the upper GI tract.

Adolescent↗
PubMed1992

Induction of the 72-kD heat shock protein in organ-cultured normal human skin.

To study the induction of heat shock protein (HSP) of normal human skin, the indirect immunofluorescence method, using monoclonal antibody directed against 72-kD HSP, was applied in organ-cultured normal human skin that was treated with heat, UV, or chemicals. The present study provided new evidence that HSP 72 was induced not only by heat and chemical agents, such as L-azetidine 2-carboxylic acid, and sodium arsenite, but also by ultraviolet (UV B and C). The result suggests that normal human skin has an induced protective function against numerous environmental stresses.

Arsenic↗