Search PubMed⌕ Search

Biomedical subjects

N Itoh

Publications and source records attributed to N Itoh.

At least 271 records · Page 15Linked to original sources
PubMed1996

High prevalence of antibodies to glutamic acid decarboxylase in comparison to islet cell antibodies in patients with long-standing insulin-dependent diabetes mellitus.

To elucidate the clinical significance of antibodies to glutamic acid decarboxylase (GAD Ab) compared to islet cell antibodies (ICA) in recent-onset and long-standing insulin-dependent diabetes mellitus (IDDM). We examined GAD Ab and ICA in 29 recent-onset and 85 long-standing patients with IDDM. GAD Ab was detected by a radioimmunoassay kit using purified pig brain GAD as an antigen. The prevalence of GAD Ab in the recent-onset diabetic patients was 55.2%, slightly lower than that of ICA (65.5%). In contrast, the prevalence of GAD Ab in long-standing diabetic patients was 42.4%, which was significantly higher than that of ICA (23.5%) (p < 0.01). GAD Ab were consistently detected in approximately 40% of patients with long-standing disease, while ICA decreased according to duration of disease. The GAD Ab titer in ICA-positive patients (mean +/- SD, 1588.2 +/- 6755.1; range, 6-38574) was significantly higher than that in ICA-negative patients (mean +/- SD, 13.4 +/- 17.9; and range, 5-72 units) (p < 0.001). These findings suggest that GAD Ab are more useful than ICA to know participation of immune disorders in long-standing patients with IDDM.

Adult↗
PubMed1996

Intramyocardial pulsed Doppler echocardiography as a new modality for evaluation of left ventricular wall motion: assessment in normal subjects.

Doppler tissue imaging-guided pulsed Doppler echocardiography can record velocities of the regional ventricular wall, but the potential clinical applications have not yet been investigated. To propose a new modality for assessment of left ventricular wall dynamics, we investigated the longitudinal and latitudinal motions of the normal left ventricular wall with intramyocardial pulsed Doppler echocardiography under tissue imaging guidance, and characterized the velocity patterns in 31 normal subjects or normal volunteers (mean age 38 +/- 18 years old). Velocity patterns of the septal and posterior walls were recorded and compared using the parasternal and apical approaches. The apical approach showed that the entire left ventricle moved, coded in red, toward the transducer during systole, and moved away, coded in blue, during diastole. Pulsed Doppler echocardiography recorded the systolic S, early diastolic E and presystolic A waves from both windows. All three waves had higher velocities in the apical compared to the parasternal approach, and the velocities of S and E waves were increased more in the posterior wall than in the septum. Thus, the A/E ratio was significantly lower in the posterior compared to the septal wall (0.63 +/- 0.3 and 0.77 +/- 0.3, respectively, in the apical approach) and the A/E ratio of transmitral inflow was between those of the walls. Apical intramyocardial pulsed Doppler echocardiography can accurately evaluate septal and posterior wall dynamics. The present study provides important basic data for assessing regional myocardial function.

Adult↗
PubMed1996

[Rapid detection and identification of human adenovirus directly from conjunctival scrapings by polymerase chain reaction and restriction fragment length polymorphism analysis].

Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis were combined for detection and identification of adenovirus (Ad), a common agent of conjunctivitis in Japan. Nested-PCR with two primer sets that hybridize to the conserved region for hexon protein of 14 prototypes of Ad serotype 1 to 8, 11, 14, 19, 37, 40, and 41, amplified 956 bps DNA fragment. The amplified fragments from 14 prototypes were completely differentiated with the combination of three restriction endonucleases, Eco T14I, Hae III, and Hin fI. We applied this new method to 70 conjunctival scrapings from patients with conjunctivitis, and compared the results with those of the combination of culture isolation and neutralization test. PCR was positive in 38 out of 70 samples (54.3%), whereas 33 of 70 samples (47.1%) were positive by cell culture. Compared with cell culture isolation, the PCR method had a sensitivity of 100% (33 of 33). Positive PCR samples were further classified into Ad 37 (44.7%), 3 (39.5%), 11 (7.9%), 8 (5.3%), and 4 (2.6%) by PCR-RFLP analysis. Of five samples that were PCR positive and cell culture negative, three samples were Ad 37 and two were Ad 8 by PCR-RFLP analysis. These differentiations of cell culture positive samples were identical to the results of the neutralization test. It took only about three days to detect and identify Ad by PCR-RFLP analysis, whereas it took at least two weeks by culture isolation and neutralization test. Our newly developed method of detecting and typing human Ad by PCR-RFLP analysis is more sensitive, accurate, and prompt than the conventional cell culture isolation and neutralization test.

Adenovirus Infections, Human↗
PubMed1996

Serotyping of Chlamydia trachomatis from inclusion conjunctivitis by polymerase chain reaction and restriction fragment length polymorphism analysis.

A molecular biological method of detecting and serotyping Chlamydia trachomatis (C. trachomatis) directly from conjunctival specimens by polymerase chain reaction (PCR) was developed and applied to the diagnosis of inclusion conjunctivitis. We amplified 1.2 kbp DNA fragments of ompA gene from 15 reference strains of C. trachomatis by two-step PCR using two pairs of primers. Restriction fragment length polymorphism analysis using a combination of three endonucleases (HinfI, HindIII and HhaI) completely differentiated 13 of the 15 serovars; the exceptions were B and Ba. We then used this method for 18 strains of C. trachomatis isolated from Japanese patients with inclusion conjunctivitis, serotyping them into six groups: D (5/18), G (5/18), E (3/18), H (2/18), F (1/18), and K (1/18). In our comparison of cell culture isolation with PCR analysis of 38 conjunctival swabs from 35 patients in Sapporo with follicular conjunctivitis, 8 were positive in culture isolation and were also positive in two-step PCR. Twenty-five of 26 strains (the 18 isolated strains and 8 strains amplified by two-step PCR) were genotyped to D, G, H, E, F, and K. One isolated strain could not be identified. The C. trachomatis which causes inclusion conjunctivitis in Japan appears to have a distribution of serovars similar to that of the sexually transmitted diseases.

Adolescent↗
PubMed1996

Radioimmunoprecipitation assay for glutamic acid decarboxylase antibodies evaluated clinically with sera from patients with insulin-dependent diabetes mellitus.

We evaluated a new, commercially developed radioimmunoprecipitation assay for measuring glutamic acid decarboxylase (GAD) antibodies by using recombinant human GAD65. The intra- and interassay CVs were 8.0% (n = 20) and 8.6% (n = 15), respectively. We found GAD antibodies in 74% (23 of 31; 95% confidence interval 55-88%), 70% (14 of 20; 46-88%), and 65% (28 of 43; 49-79%) of patients at, respectively, < or = 1 year, 1-2 years, and 2-4 years after the onset of insulin-dependent diabetes mellitus (IDDM) and in 30% (30 of 99; 21-40%) of patients with long-term diabetes (4-22 years). We also detected GAD antibodies in 8% (9 of 106; 4-16%) of patients with non-insulin-dependent diabetes mellitus (NIDDM). The frequency of GAD antibodies in the NIDDM group was markedly higher in the insulin-deficient patients [67% (6 of 9; 30-93%)], who initially were nonketotic and non-insulin-dependent for > or = 6 months but later became insulin dependent, than in the non-insulin-deficient patients [3% (3 of 97; 1-9%)]. This new commercial assay is easy to use and provides a specific and sensitive method for evaluating GAD antibodies in IDDM.

Adolescent↗
PubMed1995

A long-term receptor stimulation is requisite for angiotensin II-dependent DNA synthesis in vascular smooth muscle cells from spontaneously hypertensive rats.

Angiotensin II stimulates DNA synthesis in aortic smooth muscle cells prepared from spontaneously hypertensive rats, with maximal levels detected 20 h after stimulation. Angiotensin II receptor antagonists inhibited the angiotensin II-induced DNA synthesis. In particular, the noncompetitive antagonist 2-ethoxy-1-[[2'(1 H-tetrazol-5-yl) biphenyl-4-yl]methyl]-1 H-benzimidazole-7-carboxylic acid (CV11974) was more effective than expected from its affinity for the angiotensin II receptor and its potency for inhibiting angiotensin II-induced increase in cytosolic free Ca2+ concentration 2-n-Butyl-4-chloro-5-hydroxymethyl-1-[(2'-(1 H-tetrazol-5-yl)biphenyl-4-yl) methyl]imidazole, potassium salt (losartan), one of the antagonists, inhibited angiotensin II-induced DNA synthesis by 92% and 79%, even when added 2 and 4 h after angiotensin II stimulation, respectively. Angiotensin II also increases the mRNA of platelet-derived growth factor-A chain and basic fibroblast growth factor. The increase was observed within 4 h after angiotensin II stimulation. In this case, the addition of losartan at 4 h after angiotensin II stimulation hardly influenced the time course of the mRNA level of growth factors. Also, conditioned media of cells stimulated with angiotensin II did not influence DNA synthesis in the presence of CV11974. These results suggest that sustained receptor stimulation with angiotensin II is required for DNA synthesis in addition to the early intracellular signaling following phospholipase C activation in a manner independent of the induction of growth factors such as platelet-derived growth factor-AA and basic fibroblast growth factor.

Angiotensin II↗
PubMed1995

Rare occurrence of p53 and ras gene mutations in preneoplastic and neoplastic mouse endometrial lesions induced by N-methyl-N-nitrosourea and 17 beta-estradiol.

To examine K-, H-, or N-ras and p53 gene mutations in mouse endometrial carcinogenesis induced by N-methyl-N-nitrosourea and 17 beta-estradiol, we performed polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) in 13 adenocarcinomas and 11 other preneoplastic lesions. A significant shifted band in exon 5 of p53 using PCR-SSCP was detected in one of 13 adenocarcinomas. Direct sequencing showed that the mutation was TCA-to-TGA (Ser-to-End) transition. These results suggest that ras gene mutations were not related to carcinogenesis and inactivation of p53 may occur with low frequency during the mouse endometrial carcinogenesis in this model.

Adenocarcinoma↗
PubMed1995

[Testicular findings, endocrine features and therapeutic responses of men with idiopathic hypogonadotropic hypogonadism].

The purpose of this study is to clarify the pathological and endocrinological variations of male idiopathic hypogonadotropic hypogonadism (IHH) from the viewpoint of testicular maturation. Twenty-five patients with IHH were classified into 3 groups according to the degree of germ cell maturation. The most mature germ cells in patients with severe IHH, moderate IHH and mild IHH were spermatogonia, primary spermatocytes and postmeiotic germ cells, respectively. All patients were treated with hCG alone or a combination of hMG-hCG for 1 year or more. The therapeutic efficacy of gonadotropin therapy was evaluated by findings of semen analysis, spermatogenesis and sexual maturation. The total GCI, which was expressed as the number of germ cells per Sertoli cell, diameter of the seminiferous tubules and testicular volume in mild IHH were the largest among the 3 IHH groups, and those in severe IHH were the smallest. Even in mild IHH, spermatogonial proliferation and meiotic activity were quantitatively smaller than those of normal pubertal boys. All patients showed extremely low basal testosterone levels. Response of serum testosterone to hCG administration correlated to the maturity of germ cells. Basal serum gonadotropin levels and responses to GnRH administration varied widely among the 3 groups. In particular, the response of serum gonadotropin to GnRH correlated to the maturity of the germ cells. Spermatogenesis could be initiated by hCG alone in IHH patients without cryptorchidism. Normal sperm density was obtained by hCG alone in the case of mild IHH; however, in moderate and severe IHH groups, hMG-hCG therapy was required for sufficient spermiogenesis. Sexual maturation was completely obtained by gonadotropin therapy within 1 year in moderate and mild IHH. However, in severe IHH, satisfactory sexual maturation could not be obtained within 1 year. The therapeutic prognosis for sexual maturation could be made based on the response to the hCG test at 6 months of gonadotropin therapy. In conclusion, the maturity of germ cells before treatment, which varies widely among patients with IHH, is a sensitive parameter for hypothalamo-pituitary-testicular function and the efficacy of gonadotropin therapy for testicular function. In severe IHH groups, to obtain satisfactory sexual maturation, the administration of testosterone should be considered in addition to gonadotropin replacement.

Adolescent↗
PubMed1995

Expression of insulin receptor-related receptor mRNA in the rat brain is highly restricted to forebrain cholinergic neurons.

Insulin receptor-related receptor (IRR) is a member of the insulin receptor family. However, its endogenous ligand and the physiological roles of IRR are unknown. To elucidate the physiological roles of IRR in the brain, we examined the expression of its mRNA in the rat brain by in situ hybridization. In contrast to the widespread expression of insulin receptor and insulin-like growth factor-1 receptor mRNAs in the brain, the expression of IRR mRNA was highly restricted to the forebrain cholinergic neurons. All the forebrain cholinergic neurons expressed IRR mRNA. The present findings indicate that IRR has a selective role in the brain for forebrain cholinergic function.

Animals↗
PubMed1995

The safe and complete removal of a carotid body tumor with elements suggestive of a malignant potential by employing an intraluminal shunt: report of a case.

The carotid body tumor is a relatively rare neoplasm arising from the intercarotid paraganglions. We report herein the case of a patient with a Shamblin group 2 type carotid body tumor for which safe and successful removal was facilitated by the insertion of an intraluminal shunt. The patient was a 54-year-old man who presented with a spherical elastic mass, 4.8 x 3.7 cm in size, on the right anterior aspect of his neck, which was diagnosed as a carotid body tumor by diagnostic imaging. Because the tumor was suspected to be malignant based on the operative findings, which included invasive adhesion to the carotid artery, an intraluminal shunt was inserted, allowing for safe and complete removal. Histologically, this tumor showed malignant potential with sporadic mitoses and incomplete capsular invasion. Thus, it is recommended that an intraluminal shunt be employed for the removal of a carotid body tumor when it is found to be tightly adherent to the carotid artery during the operation.

Anastomosis, Surgical↗
PubMed1995

No detectable cytomegalovirus and Epstein-Barr virus genomes in the pancreas of recent-onset IDDM patients.

Viral infection is assumed to trigger or exacerbate autoimmune responses against pancreatic beta cells leading to the development of insulin-dependent diabetes mellitus (IDDM). We therefore examined by polymerase chain reaction the presence of two candidate viruses, cytomegalovirus and Epstein-Barr virus, in IDDM pancreases. Pancreas tissues were obtained by biopsy under laparoscopy from 16 recent-onset IDDM patients: age 17-53 years; disease duration 0-7 months; six had flu-like symptoms before onset. Frozen sections were made and subjected to DNA amplification. DNA samples were prepared from the frozen sections and polymerase chain reaction was performed using primers specific to cytomegalovirus, Epstein-Barr virus and control gene for HLA-DP. Cytomegalovirus- and Epstein-Barr virus-infected cells were used for positive control. Southern blot analysis could detect cytomegalovirus DNA from as few as 2 x 10(-1) cytomegalovirus-infected cells and Epstein-Barr virus DNA from two Epstein-Barr virus-infected cells. This highly sensitive analysis, however, could not detect cytomegalovirus or Epstein-Barr virus genomes in pancreases of recent-onset IDDM. A single copy human gene (HLA-DP) was amplified from all IDDM pancreases indicating that DNA amplification was performed without inhibition. We conclude that cytomegalovirus or Epstein-Barr virus genomes are unlikely to exist in pancreas biopsy specimens of recent-onset IDDM patients.

Adolescent↗
PubMed1995

Molecular cloning of cDNAs for immunoglobulin variable regions of a monoclonal anti-idiotypic antibody specific for sigma receptors.

In previous work on sigma (sigma) receptors, we established a hybridoma cell line, 10G9, producing a monoclonal anti-idiotypic antibody (anti-Id mAb) to the monoclonal and anti-haloperidol antibody. The anti-Id mAb showed specific binding affinity to sigma receptors in immunoprecipitation and competition experiments. Here we isolated and sequenced cDNA clones for the variable regions of the anti-Id mAb. These combinations of segments and formation of the unique CDR3 were considered to be the structural basis for the diversity of the antigen-binding site of our anti-Id mAb and, therefore, for its binding activity to sigma receptors.

Amino Acid Sequence↗
PubMed1995

Mitochondrial DNA mutations in pancreatic biopsy specimens from IDDM patients.

We investigated the contribution of mitochondrial DNA mutations to the pathogenesis of IDDM by analyzing mitochondrial DNA in pancreatic biopsy specimens and peripheral blood cells from 18 patients with newly-diagnosed IDDM. All patients presented with typical abrupt onset of diabetes and ketosis on initial examination. Point mutations at nucleotides 3243, 3271 and 8344 were assayed by polymerase chain reaction and restriction fragment length polymorphism analysis or by mismatch-primer analysis. A common large deletion from nucleotides 8483-13459 was analyzed by a primer shift method. All of these mutations are known to be pathogenic mutations. However, none of the mitochondrial DNA mutations were detected in any of 18 IDDM patients. Several types of mitochondrial DNA mutation have been identified in the peripheral blood cells in some patients with non-insulin-dependent diabetes mellitus as well as in some with IDDM, however, our results suggest that abrupt-onset IDDM does not correlate with any of the known mitochondrial DNA mutations.

Adolescent↗
PubMed1995

Localization of fibroblast growth factor-9 mRNA in the rat brain.

We examined the localization of fibroblast growth factor-9 (FGF-9) mRNA in the rat brain by in situ hybridization. FGF-9 mRNA was moderately or weakly expressed in widespread regions including the olfactory bulb, caudate putamen, cerebral cortex, hippocampus, thalamus, hypothalamus, midbrain, brainstem and cerebellum. However, FGF-9 mRNA was also strongly expressed in several specific nuclei including the red nucleus and oculomotor nucleus in the midbrain, the vestibular nucleus and facial nucleus in the brainstem and the medial cerebellar nucleus, interposed cerebellar nucleus and lateral cerebellar nucleus in the cerebellum. The cellular localization of FGF-9 mRNA indicated that the mRNA in the rat brain was expressed preferentially in neurons, although FGF-9 was originally isolated from human glioma cells. The localization profile of FGF-9 mRNA is different from those of aFGF, bFGF and FGF-5 mRNAs reported previously. The present findings indicate that FGF-9 has a unique role in the brain.

Animals↗
PubMed1995

Transient expression of FGF receptor-4 mRNA in the rat cerebellum during postnatal development.

The fibroblast growth factor (FGF) receptor-4 mRNA in the adult rat brain is expressed preferentially in the medial habenular nucleus. In this paper, we examined the expression of FGFR-4 mRNA in the brain during postnatal development. Interestingly, in addition to the persistent expression of FGFR-4 mRNA in the medial habenular nucleus, FGFR-4 mRNA was transiently expressed in the proliferative zone of the external granule layer of the developing cerebellum. The localization and transient expression of FGFR-4 mRNA in the developing cerebellum suggest that FGFR-4 mRNA was expressed by proliferative granule cells. The present findings indicate that FGFR-4 in the brain has an important role in the postnatal development of the cerebellar cortex.

Animals↗