Biomedical subjects

N Kato

Publications and source records attributed to N Kato.

At least 271 records · Page 15Linked to original sources

PubMed1999

A comparative study of endoscopic trigonoplasty for vesicoureteral reflux in children and in adults.

BACKGROUND: Endoscopic trigonoplasty is an experimental therapy for vesicoureteral reflux. We investigated differences in surgical results between children and adults. METHODS: Endoscopic trigonoplasty was performed on 51 patients and 15 pediatric and 21 adult patients were included in this study. The children accounted for 27 cases of refluxing ureter (grade II, 8; III, 14; IV, 4; V, 1) and the adults for 28 cases (I, 4; II, 18; III, 4; IV, 2). There was a greater proportion of bilateral disease and a higher average degree of reflux in the children's group. RESULTS: We found no significant differences in operative time, complications, analgesics usage, the duration of the indwelling catheter and hospital stay. Our follow up at 3 months showed that the reflux had ceased in 19 of 27 cases (70%) in the children's group and in 27 of 28 cases (96%) in the adults' group. The next follow up at 12 months showed that there was no reflux in 16 of 27 cases (59%) in 15 children and in 17 of 23 adult cases (74%). Trigonal splitting caused recurrence of reflux greater than grade II, in two children (13%) affecting four ureters and in three adults (14%) affecting four ureters. CONCLUSIONS: Endoscopic trigonoplasty has proved to be equally less invasive in children and in adults, but vesicoureteral reflux was less often resolved in children. This suggests that the greater original distance between the ureteral orifices and the greater thickness of the detrusor muscle favor the adult patient. For children, a new surgical concept is needed to increase cessation rate of vesicoureteral reflux.

Adult↗

PubMed1999

Nasal and nasal-type T/NK-cell lymphoma with cutaneous involvement.

Natural killer (NK) cells are a third lymphocyte lineage, in addition to B- and T-cells, that mediate cytotoxicity without prior sensitization. NK cells also have phenotypic and genotypic characteristics; they express the NK-related antigen CD56 and T-cell markers such as CD2 and CD3 epsilon, but their T-cell receptor (TCR) locus is not rearranged. Non-Hodgkin's lymphomas are divided into B- and T-cell neoplasms and NK-cell lymphomas. We describe 2 Japanese patients with nasal and nasal-type T/NK-cell lymphoma in which the skin, nasal/nasopharyngeal region, bone marrow, and lymph node were the sites of involvement. The clinical and histopathologic findings were recorded. In addition, immunophenotyping, TCR gene rearrangement, and the existence of Epstein-Barr virus (EBV) DNA by polymerase chain reaction amplification were determined. Clinically, the cutaneous eruptions were purplish, hard, multiple nodules. Histologically, angiocentric proliferation of small-to medium-sized, pleomorphic, lymphoid cells were observed. They revealed hand-mirror-shaped lymphocytes with azurophilic granules with the use of Giemsa staining by touch smear. These lymphocytes were found to be positive to immunophenotyping for CD2 (Leu5b), CD3 epsilon (DAKO), CD4 (Leu3a), and CD56 (Leu 19). No clonal rearrangement of TCR-beta, -gamma, and -delta genes and immunoglobulin gene markers were found, and no positive results of identification of EBV DNA were shown. The patients underwent cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy with complete remission; however, both had recurrence of disease. Because NK-cell lymphomas express some T-cell markers, they may be mistakenly diagnosed as peripheral T-cell lymphomas if they are not investigated for the NK-cell-specific marker, CD56. Therefore the importance of immunophenotypic investigations of CD56 should be stressed. Also, the importance of clinical investigation of nasal/nasopharyngeal lymphomas should be stressed when NK-cell lymphoma is diagnosed involving the skin, because NK-cell lymphomas are often associated with the nasal and nasopharyngeal region.

Aged↗

PubMed1999

Paroxysmal kinesigenic choreoathetosis locus maps to chromosome 16p11.2-q12.1.

Paroxysmal kinesigenic choreoathetosis (PKC), the most frequently described type of paroxysmal dyskinesia, is characterized by recurrent, brief attacks of involuntary movements induced by sudden voluntary movements. Some patients with PKC have a history of infantile afebrile convulsions with a favorable outcome. To localize the PKC locus, we performed genomewide linkage analysis on eight Japanese families with autosomal dominant PKC. Two-point linkage analysis provided a maximum LOD score of 10.27 (recombination fraction [theta] =.00; penetrance [p] =.7) at marker D16S3081, and a maximum multipoint LOD score for a subset of markers was calculated to be 11.51 (p = 0.8) at D16S3080. Haplotype analysis defined the disease locus within a region of approximately 12.4 cM between D16S3093 and D16S416. P1-derived artificial chromosome clones containing loci D16S3093 and D16S416 were mapped, by use of FISH, to 16p11.2 and 16q12.1, respectively. Thus, in the eight families studied, the chromosomal localization of the PKC critical region (PKCR) is 16p11.2-q12.1. The PKCR overlaps with a region responsible for "infantile convulsions and paroxysmal choreoathetosis" (MIM 602066), a recently recognized clinical entity with benign infantile convulsions and nonkinesigenic paroxysmal dyskinesias.

Adolescent↗

PubMed1999

Excretion into bile of a novel unenveloped DNA virus (TT virus) associated with acute and chronic non-A-G hepatitis.

Recently, an unenveloped, single-stranded DNA virus named TT virus (TTV) has been reported in association with hepatitis of non-A-G etiology. Five patients with TTV viremia, who received bile drainage or cholecystectomy, were tested for TTV DNA in bile by polymerase chain reaction with heminested primers. TTV DNA was detected in bile from all patients; titers were 10-100 times higher than in serum in 4 and at a comparable level in the remaining 1 patient. TTV DNA was detected in feces, also, in 1 of the 2 patients tested. The buoyant density of TTV in bile from 1 tested patient (1.33-1.35 g/cm3) was the same as that in feces (1.32-1.35 g/cm3). TTV may be secreted via bile into feces in a transmissible form and would spread by a fecal-oral route for deep and wide penetration into the general population.

Acute Disease↗

PubMed1999

Three-dimensional coronary magnetic resonance angiography with injection of extracellular contrast medium.

RATIONALE AND OBJECTIVES: To evaluate serial changes of the signal intensity and the contrast-to-noise ratios of the coronary arteries on three-dimensional (3D) coronary magnetic resonance angiography (MRA) after an injection of extracellular contrast medium, and to demonstrate the feasibility of this method for the diagnosis of coronary artery abnormalities. METHODS: Five healthy volunteers and two patients with Kawasaki disease and an anomalous coronary artery were studied. Coronary MRAs of the left anterior descending artery and the right coronary artery were obtained using a fat-suppressed 3D MRA sequence before and 0 to 5, 10 to 15, 20 to 25, and 30 to 35 minutes after administration of Gd-DTPA-BMA. RESULTS: Administration of the contrast agent provided a significant increase in the signal intensity and contrast-to-noise ratio. Aneurysm of the left anterior descending artery in Kawasaki disease and the proximal course of the anomalous right coronary artery, which were not well depicted on precontrast 3D MRA, were clearly demonstrated after contrast injection. CONCLUSIONS: The current study demonstrated that the use of an extracellular gadolinium contrast agent can significantly improve the clinical usefulness of 3D coronary MRA.

Adolescent↗

PubMed1999

Dose-dependency and rate of decay of efficacy of Resovist on MR images in a rat cirrhotic liver model.

RATIONALE AND OBJECTIVES: To investigate the dose-dependency and half-life of decay of the signal reduction by super-paramagnetic iron oxides on three different spin-echo images in a rat model of cirrhosis. METHODS: For normal and cirrhotic liver, signal intensities were measured 15 minutes after injection of Resovist (range, 1-40 mumol Fe/kg) on three different spin-echo images. Subsequently, recovery of signal intensity was monitored up to 2 weeks after injection. RESULTS: The dose-dependency of efficacy was somewhat less at all doses and imaging parameters in cirrhotic liver. However, the submaximal effect was obtained at a dose of 20 mumol Fe/kg, the same as in normal liver. The rate of decay of the efficacy in cirrhotic liver was similar to or faster than that in normal liver. CONCLUSIONS: The dose-dependency and rate of decay of efficacy of Resovist in cirrhosis were similar to those in normal liver, although the efficacy was less in cirrhotic liver and both the dose-dependency and rate of decay of efficacy were dependent on imaging parameters.

Animals↗

PubMed1999

Angiotensinogen gene and essential hypertension in the Japanese: extensive association study and meta-analysis on six reported studies.

BACKGROUND: Accumulating evidence has supported the pathophysiological role of angiotensinogen in essential hypertension. However, some studies of molecular genetics have implicated that there may be an ethnic variation concerning the disease susceptibility of the AGT gene. OBJECTIVES AND METHODS: To evaluate the importance of this candidate gene for hypertension, we undertook an extensive association study in the Japanese. This case-control study was conducted in a total of 1232 individuals consecutively enrolled in a single institution, divided into two subgroups: one subgroup comprised 254 hypertensive and 224 normotensive subjects and the other comprised 463 hypertensive and 291 normotensive subjects. A meta-analysis was subsequently performed on six Japanese studies including the present study. RESULTS: No significant association was observed between a molecular variant of AGT, Thr235, and hypertension status in our case-control study. Moreover, this finding was extendible to another AGT polymorphism, G-6A, one of the potential functional polymorphisms in the promoter region, because these two polymorphisms proved to be in complete linkage disequilibrium in the studied population. The meta-analysis revealed that the pooled estimate of the odds ratio across the studies was 1.22 (95% CI 1.05-1.42), and that there was significant evidence against homogeneity of the odds ratios among the studies included (phi2 = 19.8, df = 5, P = 0.0014). In particular, a large range of variation (60-83%) was found for the allele frequency of Thr235 among control subjects of the six Japanese case-control studies. CONCLUSIONS: Although the meta-analysis appears in favour of association between the AGT variant and essential hypertension in the Japanese, there is considerable heterogeneity among the studies and the evidence is also rather borderline. Further comprehensive approaches are needed to resolve this debatable issue.

Adult↗

PubMed1999

Metastatic cutaneous plasmacytoma: a case report associated with IgA lambda multiple myeloma and a review of the literature of metastatic cutaneous plasmacytomas associated with multiple myeloma and primary cutaneous plasmacytomas.

We present the case of a 67-year-old Japanese woman with immunoglobulin A lambda (IgA lambda) multiple myeloma (MM). She had firm nodular cutaneous lesions on the trunk and scalp without adjacent bone involvement. The patient was diagnosed as having IgA lambda MM of stage IIIA with 52% plasmacytosis in the bone marrow six months before the appearance of the cutaneous lesions. The abnormal plasma cells showed moderate to marked dysplasia in both the bone marrow and skin lesions. The abnormal plasma cells in the bone marrow exhibited abnormal karyotypes: 41, XX, der (1) t (1p; 1q), -4, -10, -14, -16, -17, 17p+, that differed from the "unfavorable" karyotype reported previously. We reviewed the cases of metastatic cutaneous plasmacytoma in MM and cases of primary cutaneous plasmacytoma that have been reported in English or Japanese and identified the Ig class. Among the 83 cases of metastatic cutaneous plasmacytomas in MM, IgG, IgA, IgD, and Bence-Jones protein were found in 52%, 23%, 16%, and 6%, respectively. A disproportionately high frequency of IgD lambda MM was found to have spread to the skin, compared with the frequency of IgD MM itself, which was present in only around 2% of the MM cases. Among the 18 primary cutaneous plasmacytomas, IgG, IgA, and Bence-Jones protein were found in 56%, 11%, and 17%, respectively, but no IgD was found.

Aged↗

PubMed1999

Paraneoplastic syndromes of leukocytosis, thrombocytosis, and hypercalcemia associated with squamous cell carcinoma.

Paraneoplastic syndromes including leukocytosis, thrombocytosis and hypercalcemia are occasionally seen in patients suffering from progressive malignant disorders. Recent studies have revealed the production of several humoral factors by tumor cells and normal splenic cells of tumor-bearing patients to be the major cause of these reactions. Granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte-colony stimulating factor (G-CSF), parathyroid hormone-related peptide, interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF) have been implicated. We describe a 58-year-old Japanese man with squamous cell carcinoma (SCC) on the left sole, which developed in a deep linear scar after a train crash. He developed pulmonary and lymph node metastases, then leukocytosis (57,110/mm3 with 95% neutrophilia), thrombocytosis (86.3 x 10(4)/mm3), and hypercalcemia (7.0 mEq/1), and finally cachexia, followed by death. Serum G-CSF, IL-1 alpha, IL-1 beta, and TNF-beta were determined; revealing G-CSF and IL-1 beta levels were above the upper limits of their normal ranges at 39.2 pg/ml and 4.63 pg/ml, respectively. It is probable that these humoral factors were partially responsible for the paraneoplastic syndromes induced by the cutaneous SCC with metastasis in the present case.

Animals↗

PubMed1999

Hydroxyurea-related leg ulcers in a patient with chronic myelogenous leukemia: a case report and review of the literature.

The unusual appearance of extensive skin ulcerations has been reported in patients with chronic myelogenous leukemia (CML) undergoing continuous chemotherapy with hydroxyurea. It is thought that hydroxyurea, an antineoplastic agent with selective cytotoxicity for cells that divide most actively (such as those of the skin), causes these ulcerations through impairment of normal wound healing in areas of common trauma. The most common site of ulcers is the leg, where the ulcers are often extremely painful, with violaceous macules surrounding them, and are associated with extensive edema. On biopsy, histological vascular changes include leukocytoclastic vasculitis, perivascular lymphocytic infiltration, formation of thrombus, swelling of the endothelial cells, and thickening of the vascular walls. We report successful split-thickness skin grafting on hydroxyurea-related leg ulcers after preoperative discontinuation of hydroxyurea treatment in a patient with CML. The possible pathogenesis of hydroxyurea-related leg ulcers is discussed.

Antineoplastic Agents↗

PubMed1999

Crystallization of lipopolysaccharide from a Salmonella typhimurium semi-rough (SR) mutant.

Salmonella typhimurium SR-form lipopolysaccharide (LPS), consisting of a single repeating unit of the O-antigenic polysaccharide, linked to the R-core consisting of oligosaccharide that is, in turn, linked to lipid A, formed crystals whose shapes were hexagonal plates, discoids, and solid columns when precipitated by the addition of 2 volumes of 95% ethanol containing 375 mM MgCl2 and kept in 70% ethanol containing 250 mm MgCl2 at 4 C for 10 days. Among these crystals, the basic form is considered to be the hexagonal plates. Analyses of hexagonal plate crystals showed that they consist of hexagonal lattices with a lattice constant (a axis) of 4.62 A and longitudinal axis (c axis) of approximately 100 A. In X-ray diffraction patterns in the low-angle region, crystals of S. typhimurium SR-form LPS exhibited much less distinct reflections when compared with crystals of synthetic Escherichia coli-type lipid A. In contrast to the previous finding that S. minnesota S-form LPS possessing the O-antigenic polysaccharide does not crystallize under the same experimental conditions as used in the present study, the presence of a single repeating unit of the O-antigenic polysaccharide does not inhibit crystallization.

Carbohydrate Conformation↗

PubMed1999

Lactoferrin inhibits hepatitis C virus viremia in patients with chronic hepatitis C: a pilot study.

Hepatitis C virus (HCV) is associated with the development of cirrhosis and hepatocellular carcinoma. We recently found that bovine lactoferrin, a milk protein belonging to the iron transporter family, effectively prevented HCV infection in cultured human hepatocytes (PH5CH8). We tested the hypothesis that lactoferrin inhibits HCV viremia in patients with chronic hepatitis C. Eleven patients with chronic hepatitis C received an 8-week course of bovine lactoferrin (1.8 or 3.6 g/day). At the end of lactoferrin treatment, a decrease in serum alanine transaminase and HCV RNA concentrations was apparent in 3 (75%) of 4 patients with low pretreatment serum concentrations of HCV RNA. However, 7 patients with high pretreatment concentrations showed no significant changes in these indices. This pilot study suggests that lactoferrin is one potential candidate as an anti-HCV reagent that may be effective for the treatment of patients with chronic hepatitis.

Adult↗

PubMed1999

Mutational inactivation of mitotic checkpoint genes, hsMAD2 and hBUB1, is rare in sporadic digestive tract cancers.

Genetic instability is a key mechanism of tumorigenesis, and the instability exists at two distinct levels, the nucleotide and the chromosome levels. Disruption of the mitotic spindle checkpoint is one of the underlying mechanisms leading to aneuploidy and alterations of hsMAD2 and hBUB1, assumed to take part in the spindle checkpoint in human cells, have been found to be associated with chromosomal instability in some tumor cell lines. Therefore, we investigated the mutational status of the hsMAD2 and hBUB1 genes in 32 sporadic digestive tract cancers by reverse transcription-polymerase chain reaction-single strand conformation polymorphism analysis. The entire coding sequence of the hsMAD2 gene, and conserved regions (codons 21-152 and codons 732-1043) presumed to be functionally important in the hBUB1 gene were analyzed. Mutation of the hsMAD2 gene was not observed at all and missense mutation of the hBUB1 gene was noted in one rectal cancer case. Sequencing analysis revealed an AGT-to-GGT missense mutation, substituting glycine for serine, at codon 950, which is conserved between budding yeast and human. These results indicate that mutations of the hsMAD2 and hBUB1 genes are very rare and presumably play a very restricted role in tumor development of sporadic cancers.

Adenocarcinoma↗

PubMed1999

Familial paroxysmal kinesigenic choreoathetosis: an electrophysiologic and genotypic analysis.

PURPOSE: We report a pedigree of familial paroxysmal kinesigenic choreoathetosis (PKC) in which five of 18 members are affected. The pathophysiologic basis for PKC is still uncertain; reflex epilepsy versus dysfunction of basal ganglia. We examined (a) whether there were ictal discharges during the attacks, and (b) a linkage between PKC and possible DNA markers linked to several familial epileptic or movement disorders. METHODS: Video-monitoring EEG was performed in two patients with PKC during attacks elicited by movements of the lower extremities. Blood samples for DNA studies were obtained from 15 members of the pedigree. Fourteen polymorphic markers on chromosomes 1p, 2q, 6p, 10q, and 20q were genotyped, and two-point lod scores were calculated for each marker under a dominant model. RESULTS: No ictal discharges were found during the attacks in both patients. We could not obtain significant linkage of PKC with any marker examined. CONCLUSIONS: The video-monitoring EEG findings in our cases strongly suggested that the etiology of PKC should be considered distinct from that of reflex epilepsy. However, the patients in this pedigree had experienced generalized convulsions in their infancies; thus we could not deny the possibility of an epileptogenic basis for PKC. There was no strong evidence for a linkage of the gene for PKC with the candidate regions on 1p, 2q, 6p, 10q, or 20q.

Athetosis↗

PubMed1999

[Detection of Clostridium difficile toxin A from stool specimens by an enzyme immunoassay kit].

Toxin detection from stool specimens is prerequisite for Clostridium difficile-associated diarrhea and colitis. However, in Japan only one toxin detection kit is commercially available, which requires computerized VIDAS fluorescence reader. In this study we evaluated ImmunoCard Toxin A, which is an enzyme immunoassay with a format of individual cassette and needs no special equipment to perform, by comparing with the VIDAS CDA kit. Of 61 stool specimens 12 were positive and 39 were negative by both assays, 7 were VIDAS positive-ImmunoCard negative, 2 were VIDAS invalid-ImmunoCard negative, and 1 was invalid by both assays. Stool specimens which gave inconsistent results between two assays were subjected to cell culture assay to detect toxin B and culture for C. difficile followed by testing of toxin producibility of isolates. Of 7 VIDAS positive-ImmunoCard negative specimens 5 were negative for cell culture assay and toxigenic C. difficile culture and 2 were positive for cell culture assay. By omitting 3 VIDAS invalid specimens and counting 5 specimens, which were cell culture negative but VIDAS positive, as negative and 2, which were cell culture positive and VIDAS positive, as positive, 12 of the 14 VIDAS positive specimens were ImmunoCard positive (sensitivity, 85.7%) and all 44 VIDAS negative were ImmunoCard negative (specificity, 100%). These results indicate that although in comparison with VIDAS CDA, ImmunoCard Toxin A is slightly less sensitive, ImmunoCard is a rapid, simple, and reliable C. difficile toxin A detection kit, which has the advantage of requiring no special equipment to perform and no centrifuge step, as small as 25 muL of a specimen, and as short as approximately 15 min of time to complete the whole testing.

Bacterial Toxins↗

PubMed1999

Distribution of the cfiA gene among Bacteroides fragilis strains in Japan and relatedness of cfiA to imipenem resistance.

The cfiA gene, encoding an imipenem-hydrolyzing metallo-beta-lactamase produced by Bacteroides fragilis, and insertion-like elements were detected by PCR amplification with B. fragilis strains isolated in Japan. The cfiA gene was found in 1.9 and 4.1% of the imipenem-susceptible B. fragilis isolates collected from 1987 to 1988 and from 1992 to 1994, respectively. Insertion-like elements adjacent to the cfiA gene were found in all nine metallo-beta-lactamase-producing imipenem-resistant strains tested but not in nine cfiA-positive strains with no detectable metallo-beta-lactamase activity.

Bacterial Proteins↗

PubMed1999

Incidence of Prevotella intermedia and Prevotella nigrescens carriage among family members with subclinical periodontal disease.

We established a typing system for Prevotella intermedia and Prevotella nigrescens using the combination of PCR ribotyping and arbitrarily primed PCR (AP-PCR) fingerprinting and applied this system to the study of intrafamilial incidence of these species in the oral cavity. PCR ribotyping followed by subtyping by AP-PCR fingerprinting was applied to each type strain of P. intermedia and P. nigrescens and 54 isolates (32 isolates of P. intermedia and 24 isolates of P. nigrescens) from extraoral infections, resulting in an excellent discriminatory power (discrimination index, 0.99) for both species. A total of 18 subjects from six families, with the subjects from each family comprising the mother, the father, and a child who had subclinical early-stage to moderate adult periodontitis or simple gingivitis and who carried P. intermedia or P. nigrescens, or both, were enrolled in the study of intrafamilial carriage. When 20 colonies per specimen of subgingival plaque, if available, were picked from primary culture, 115 P. intermedia and 178 P. nigrescens isolates were recovered from the 18 subjects. Among the subjects studied, family members shared the same subtype strain(s) but non-family members did not. Multiple subtypes were found in 8 (57%) of the 14 P. nigrescens-positive subjects but in only 3 (27%) of the 11 P. intermedia-positive subjects; the difference was, however, not statistically significant (P = 0.14). These results suggest that the combination of PCR ribotyping and AP-PCR fingerprinting is well suited for the epidemiological study of P. intermedia and P. nigrescens and that each family seems to carry a distinct subtype(s) of these species.

Adolescent↗

PubMed1999

Prevalence of enterotoxigenic Bacteroides fragilis in children with diarrhea in Japan.

In age-matched controlled studies performed in Japan, enterotoxigenic Bacteroides fragilis was isolated from 14.9% of 114 children aged 1 to 14 years with antibiotic-unassociated diarrhea (AUD) and 6.5% of 108 children aged 1 to 6 years with antibiotic-associated diarrhea (AAD). The difference in comparison with control children, was significant for AUD children but not AAD children.

Adenoviruses, Human↗