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Biomedical subjects

N Itoh

Publications and source records attributed to N Itoh.

At least 397 records · Page 22Linked to original sources
PubMed1992

Chemical modification of proteins under high pressure. Preparation of ferrocene-attached bovine serum albumin and glucose oxidase.

High hydraulic pressure was used for denaturing proteins during chemical modifications. Bovine serum albumin and glucose oxidase were selected as the first targets of this unique technique and the ferrocene group was introduced into them, to obtain a macromolecular electron mediator and a self-electron-mediating oxidase, respectively. The result was compared with those obtained under non-denaturing conditions and under urea-denatured conditions. As for the number of ferrocene group linked to the protein, the pressure denaturation is superior to chemical denaturants, where ferrocenecarboxyaldehyde was used as the modifier. In both proteins the ferrocene group seemed to be introduced mainly inside the molecules with the pressure method, as the native conformation of the protein was restored when the high pressure was removed.

Ferrous Compounds↗
PubMed1992

Characterization of rat liver mannan-binding protein gene.

We previously found that rat liver mannan-binding protein (L-MBP) is encoded by two species of mRNA of 1.4 and 3.5 kb long. In this study, the structure of the gene encoding rat L-MBP was determined from the sequences of isolated genomic DNA clones and PCR amplified DNA fragments. Rat L-MBP is encoded by at least three species of mRNA, the differences among which are generated by an alternative splicing at the 5'-nontranslated region and an alternative utilization of polyadenylation sites. The rat L-MBP gene consists of six exons separated by five introns. The coding region of rat L-MBP mRNA is encoded by four exons (Exons III-VI), the 5'-noncoding region by Exons I and II, and the 3'-noncoding region by Exon VI. The exon-intron boundaries of L-MBP are completely identical to those of rat serum and human MBP, suggesting that all three MBPs are derived from a common ancestral gene.

Amino Acid Sequence↗
PubMed1992

Novel structure of the N-acetylgalactosamine containing N-glycosidic carbohydrate chain of batroxobin, a thrombin-like snake venom enzyme.

The structure of the Asn-linked carbohydrate chain of batroxobin, a thrombin-like enzyme from Bothrops atrox moojeni snake venom, has been determined. The sugar chain was isolated from batroxobin by hydrazinolysis followed by pyridylamination (PA). The PA-oligosaccharide chain was purified by HPLC on an anion exchange or reverse phase columns, and its structure was examined by sequential exoglycosidase digestion, 600 MHZ 1H NMR spectroscopy and methylation analysis. The results indicate that the oligosaccharide chain has the following structure involving a novel linkage, NeuAc alpha 2----3GalNAc.

Acetylgalactosamine↗
PubMed1992

An autopsy case of Crow-Fukase (POEMS) syndrome with a high level of IL-6 in the ascites. Special reference to glomerular lesions.

A 58-year-old man developed polyneuropathy, organomegaly, gynecomastia, skin pigmentation, and multiple myeloma (IgG-lambda type). Although transient clinical improvement was obtained with prednisolone and cyclophosphamide, his general condition deteriorated progressively, and he died 3 years after onset. Lymph nodes showed angiofollicular hyperplasia, and the sural nerve revealed segmental demyelination. At autopsy, the glomeruli were enlarged and showed mild mesangial cell proliferation with segmental mesangiolysis and proliferation of endothelial cells forming abnormal vessels. The massive volume of ascites contained a high level of interleukin-6 (IL-6). IL-6, a multifunctional cytokine, may be the pathogenic factor which induces the various clinical symptoms and pathological features of Crow-Fukase (POEMS) syndrome.

Ascites↗
PubMed1992

Polyarteritis nodosa with atrophy of the left hepatic lobe.

A 73-year-old Japanese man with a history of partial gastrectomy due to gastric cancer 4 years previously was admitted because of intermittent fever. The patient developed abdominal pain, erythema, and myalgia in addition to the fever during the final clinical course, and died of acute heart failure. Autopsy disclosed atrophy of the left lobe of the liver and acute myocardial infarction. Neither metastasis nor recurrence of the cancer was observed. Small- and medium-sized arteries of the visceral organs showed various stages of necrotizing vasculitis with narrowing of the lumina. The vasculitis was most prominent in the left lobe of the liver and in the heart. Narrowing of the portal vein due to portal tract inflammation in addition to vasculitis of the hepatic arteries may have induced ischemia and infarction, which had resulted in atrophy of the left hepatic lobe.

Aged↗
PubMed1992

Immune deposits in the glomerular extracellular matrix detected by the quick-freezing and deep-etching method.

Chronic serum sickness nephritis was induced in rats by sensitization with egg albumin. The glomeruli were then examined by the quick-freezing and deep-etching method with immunohistochemical identification of immune complex deposits on replica membranes. In control rats, the glomerular basement membrane showed a three-layered structure. The middle layer was composed of a compact meshwork of fine fibrils that was connected to adjacent endothelial and epithelial cells by perpendicular fibrils in the inner and outer layers. The mesangial matrix contained a similar but looser meshwork structure. In the nephritic rats, small granular deposits were observed within the meshwork, distorting its fine structure. Larger nodular aggregates extended continuously from the middle layer to the epithelial side. Disruption of the connecting fibrils overlying these larger aggregates was noted. The deposits were stained by antiegg albumin or antirat IgG antibodies. Gold particles immunostaining for the sensitizing antigen were also localized within the deposits. These findings suggest that the deposition of immune complexes occurs in the fibrillary meshworks of the mesangium and lamina densa in this experimental model, with the resultant distortion of their meshwork structures and the formation of nodular aggregates.

Animals↗
PubMed1992

Role of cell-mediated immune reaction in blister formation of bullous pemphigoid.

In patients with bullous pemphigoid (BP), early lesions appear as exudative erythematous patches. Histologically, the inflammatory infiltrate is composed mainly of mononuclear cells (MNCs) in the erythematous lesion, although eosinophils and neutrophils are also present. The MNCs are predominantly helper/inducer T cells even in the bullous lesions. Some of the MNCs infiltrated were stained in cytoplasm by antihuman gamma-interferon (IFN-gamma) monoclonal antibody (MoAb) immunohistologically. These infiltrates are considered to produce IFN-gamma. In the bullous fluids of early BP lesions, high levels of IFN-gamma are detected by radioimmunoassay using antihuman IFN-gamma MoAb. The results suggest that infiltrating lymphocytes are stimulated immunologically in BP bullous lesions. Cell-mediated immune reaction as well as autoantibody to the basement membrane zone may also play an important role in blister formation in BP.

B-Lymphocytes↗
PubMed1992

Stimulation of angiotensinogen production in primary cultures of rat hepatocytes by glucocorticoid, cyclic adenosine 3',5'-monophosphate, and interleukin-6.

The effects of hormones and cytokines on angiotensinogen production were studied in primary cultured rat hepatocytes. The basal secretion of angiotensinogen decreased during culture. The addition of dexamethasone and (Bu)2cAMP completely prevented this decrease. Angiotensinogen secretion by freshly plated hepatocytes was slightly increased in response to dexamethasone, but after 24 h in culture, hepatocytes no longer responded to dexamethasone alone. When hepatocytes were treated with (Bu)2cAMP, glucagon, or forskolin, angiotensinogen secretion increased in response to dexamethasone in a concentration-dependent manner. 17 beta-Estradiol and T3 failed to stimulate angiotensinogen secretion in either the presence or absence of (Bu)2cAMP. Interleukin-6 (IL-6) exhibited a stimulatory activity on angiotensinogen secretion, which was dependent on the presence of dexamethasone, whereas IL-1 and tumor necrosis factor had no effect in either the presence or absence of dexamethasone and/or (Bu)2cAMP. Unlike primary cultured hepatocytes, angiotensinogen secretion by rat hepatoma H4IIEC3 cells increased in response to dexamethasone alone. This increase was not enhanced by (Bu)2cAMP, but was enhanced by IL-6. Thus, in primary cultures of rat hepatocytes, neither glucocorticoid, cAMP, nor IL-6 alone stimulated angiotensinogen production, but a combination of glucocorticoid and cAMP or of glucocorticoid and IL-6 exhibited a stimulatory activity on angiotensinogen production. These results suggest that angiotensinogen production in the liver is synergistically regulated by these factors, whereas the hepatoma cell line H4IIEC3 lacks the regulatory mechanism of cAMP on glucocorticoid-induced angiotensinogen production.

Angiotensinogen↗
PubMed1992

Transthyretin (prealbumin) in the pancreas and sera of newly diagnosed type I (insulin-dependent) diabetic patients.

We investigated transthyretin (TTR) in the pancreases and sera of 10 newly diagnosed type I diabetic patients by immunohistochemistry and nephelometry. In the type I diabetic pancreases, glucagon-positive A-cells showed strong immunoreactivity for TTR, the intensity and distribution pattern of which corresponded to those in normal subjects. Morphometric analysis revealed that the amount of strongly TTR-positive A-cells was not significantly different from that in normal subjects. On the contrary, insulin-positive B-cells, which normally show uneven and weak TTR immunoreactivity, decreased in number, and only a few residual B-cells showed faint immunoreactivity. Neither somatostatin cells nor pancreatic polypeptide cells were positive for TTR. The serum TTR concentration showed a significant decrease in type I diabetic patients compared with that in normal subjects (P less than 0.005). These data suggest that the synthesis or storage of TTR in A-cells is not affected, but that in B-cells is impaired in type I diabetes. The decrease in serum TTR might be one of the features of metabolic disorders in type I diabetes.

Adult↗
PubMed1992

[Elucidation of biosynthetic process and regulation mechanism of bioactive peptides and their receptors].

To elucidate the mechanism of proinsulin induction by glucose, we determined the amount of proinsulin messenger ribonucleic acid (mRNA), the subcellular distribution of proinsulin mRNA and the transcriptional activity of proinsulin gene in isolated pancreatic islets of rat. From these results, we concluded that the stimulation of proinsulin synthesis was mainly regulated at the translational level. To elucidate the primary structure of vasoactive intestinal peptide (VIP) precursor, we determined the nucleotide sequence of VIP complementary deoxyribonucleic acid (cDNA). The entire amino acid sequence of the VIP precursor indicates that the precursor protein contains not only VIP but also PHI-like peptide. We also found that the induction of pro-VIP synthesis was achieved by enhancing the transcription rate of VIP gene. We also isolated fibroblast growth factor (FGF) receptor cDNA. The nucleotide sequence of FGF receptor cDNA indicates that the receptor is a transmembrane protein that contains extracellular immunoglobulin-like domains and an intracellular tyrosine kinase domain. We also found that the receptor had two isoforms of the extracellular domains and that the expression of the isoforms was regulated tissue-specifically.

Amino Acid Sequence↗
PubMed1992

[Adjuvant chemotherapy with MVP-CAB (methotrexate, vincristine, cisplatinum, cyclophosphamide, adriamycin and bleomycin) for epithelial tumors of the upper urinary tract].

Surgery plus adjuvant chemotherapy using MVP-CAB (Day 1; methotrexate 20 mg/m2, vincristine 0.6 mg/m2, cyclophosphamide 500 mg/m2, adriamycin 20 mg/m2, and bleomycin 30 mg, Day 2; cisplatinum 50 mg/m2) was conducted in 12 patients with epithelial tumors of the upper urinary tract who had unfavorable prognostic factors (progressive disease which was pT2 or more, or transitional cell carcinoma of grade 2 and 3). The MVP-CAB regimen was as follows: A total of 3 cycles were given either before or after surgery. MVP-CAB was given at 3- to 4-week intervals before surgery, or after surgery if the patient had macroscopic residual lesions. For the patients with micrometastases detected after radical surgery, MVP-CAB was given every 1 to 2 months. The median survival period of the 10 patients who underwent radical surgery was 17 months (5-59 months). The three-year survival rate of these 10 patients (Kaplan-Meier method) was 100% in grade 2 (5 patients), 100% in progressive cancer greater than pT3 (6), and 80% in grade 3 (5). In two patients, residual macroscopic lesions after surgery were confirmed. One of them initially responded to MVP-CAB but died of cancer 21 months later, while the other one did not respond and died of cancer 8 months later. Two renal pelvis cancer patients for whom radical surgery was considered impossible due to distant metastases showed remarkable tumor reduction after MVP-CAB administration (one showed CR for liver metastases and the other showed PR for lymph node metastases).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

[Adjuvant chemotherapy (MVP-CAB; methotrexate, vincristine, cisplatinum, cyclophosphamide, adriamycin, and bleomycin) for bladder cancer].

Twenty-three patients with bladder cancer (TCC; 18 patients, SCC; 5 patients) were treated with adjuvant chemotherapy (day 1: methotrexate 20 mg/m2, vincristine 0.6 mg/m2, cyclophosphamide 500 mg/m2, adriamycin 20 mg/m2, bleomycin 30 mg, day 2: cisplatinum 50 mg/m2; MVP-CAB). A total of 3 cycles of MVP-CAB were given as preoperative or postoperative therapy. The following results were obtained. Group 1 (purpose to preserve the bladder, preoperative MVP-CAB): Four of 7 patients achieved a partial response. It was possible to perform bladder preservation surgery in 3 of these 4 patients. All 3 patients had pedunculated, solitary tumors, and there was no carcinoma in situ. Group 2 (purpose to improve the prognosis; preoperative MVP-CAB): Hydronephrosis did not resolve in the 4 patients with this complication. They received total cystectomy, and 2 patients died of cancer 23 months later. Group 3 (purpose to improve the prognosis; postoperative MVP-CAB): Ten of 12 patients (total cystectomy; 10 patients, partial cystectomy; 2 patients) survived disease-free for an average of 17 months (5-44 months), 1 patient developed recurrence 12 months later, and 1 patient died of cancer 6 months later. The 1-year survival rate in Group 3 was 86% for TCC, 100% for SCC, 80% for grade 3 TCC, and 89% for pT2 or more advanced cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Enhancement by ubenimex (bestatin) of host resistance to Candida albicans infection.

Ubenimex is a low molecular weight microbial metabolite which has been demonstrated to have antitumor and immunomodulatory activities. In this study, the protective effect of ubenimex on Candida albicans infection was investigated in normal and immunosuppressed mice. In normal mice, treatment with ubenimex at 0.5, 5 and 25 mg/kg for 5 days prior to infection prolonged survival time in a dose-dependent manner. In immunosuppressed mice treated with a single dose of cyclophosphamide 4 days prior to infection, ubenimex treatment at 5 mg/kg for 5 days significantly increased the number of survivors. Ubenimex-treated mice had a significant increase in number of peritoneal exudate cells with neutrophils as well as enhanced functions, including phagocytosis and active oxygen production. These results suggest the potential usefulness of ubenimex as a prophylactic agent for the management of patients with opportunistic fungal infections.

Animals↗
PubMed1992

[A case of Castleman's disease with a variable neuropsychiatric symptomatology].

A case of 44-year-old woman who had shown psychiatric symptoms before and during the course of Castlemans' disease was presented. For four years, she first suffered from a paranoid-hallucinatory state and then a depressive one episodically. In the course of the latter, severe anemia developed. She was diagnosed as Castleman's disease, because the increased serum level of gamma-globulin and interleukin-6 (IL-6), and multiple lymphomata were evidenced. A paranoid-hallucinatory state relapsed about one year later from this episode. At last, some bulbar and cerebellar symptoms, and a delirium suddenly occurred. The ischemic changes at the level of the pons and midbrain were revealed by the magnetic resonance imaging (MRI) examination. It is certainly that both neurological and psychiatric symptoms were related to the lesions. This ischemic lesions may have resulted from the anoxia secondary to the severe anemia and/or hyperviscosity syndrome in the disease. On the other hand, the increased serum level of IL-6 as well as the ischemic lesions might have caused psychiatric symptoms in this case, as the interferone which is one of the analogues of IL-6, is known to induce emotional and behavioral symptoms.

Adult↗
PubMed1992

Urinary coagulation-fibrinolysis, kallirein-kinin systems and kininase in cases of preclampsia.

Urinary kallikrein and kallikrein activity significantly decreased in cases of preeclampsia (u-kall./CRE.index 42.39 +/- 9.66 ng/mg, u-kall. act./CRE.index 0.26 +/- 0.06 ng/min/mg), and urinary kininase II and kininase activity significantly increased (u-kininase/CRE.index 10.91 +/- 1.26 x 10(-3) IU/min/mg, u-kininase act./CRE.index 506.37 +/- 178.45 pg/min/mg) when compared with those of normal gravidas from 28 weeks to 42 weeks of gestation (u-kall./CRE.index 189.31 +/- 14.17 ng/mg, u-kall. act./CRE index 1.08 +/- 0.10 ng/min/mg, u-kininase/CRE.index 6.24 +/- 0.31 x 10(-3) IU/min/mg, u-kininase act./CRE.index 15.64 +/- 0.10 pg/min/mg). Urinary FPA, B beta 5-42, alpha 2-PI, and alpha 2PI-plasmin-complex (PIC) significantly increased in preeclampsia (u-FPA/CRE.index 23.59 +/- 8.47 ng/mg, u-B beta/CRE.index 105.26 +/- 29.30 ng/mg, u-alpha 2PI/CRE.index 121.53 +/- 43.57 ng/mg, u-PIC/CRE index 278.39 +/- 60.50 ng/mg) when compared with those of normal control group (u-FPA/CRE.index 0.92 +/- 0.04 ng/mg, u-B beta/CRE.index 12.15 +/- 0.44 ng/mg, u-alpha 2PI/CRE.index 4.18 +/- 0.33 ng/mg, u-PIC/CRE.index 5.98 +/- 1.15 ng/mg). Urinary urokinase markedly increased and urinary D-dimer was detected in severe cases of preeclampsia (u-UK/CRE.index 58.20 +/- 43.69 ng/mg, u-D-dimer 54.76 +/- 9.89 ng/ml) when compared with those of normal control group. These findings suggest that deficiency in urinary kinin excretion may induce hypertension in addition to the changes of urinary coagulation-fibrinolysis system that represents the occurrence of either the endothelial cell injury in the glomerulus or the renal tulbular damage in mild cases of preeclampsia, eventually resulting in the intra-renal vascular coagulation.

Female↗