Biomedical subjects

K Konishi

Publications and source records attributed to K Konishi.

At least 73 records · Page 4Linked to original sources

PubMed1999

Comparison of bioelectrical impedance analysis and dual energy X-ray absorptiometry for assessment of body composition in children.

BACKGROUND: There are a variety of methods for assessing body composition. Bioelectrical impedance analysis (BIA) is an easy and non-invasive technique, but has limitations in underweight and overweight subjects. Few reports have investigated the validity of BIA in children. In this report, the characteristics of BIA, especially in overweight and underweight children, are assessed and the results are compared with those of dual energy X-ray absorptiometry (DXA), as a reliable method for assessing body composition. METHODS: Determination of the fat-free mass (FFM), body fat content and percent body fat (%fat) was carried out using both BIA and DXA. The subjects (60 males and 44 females) were divided into five groups according to the percentage of ideal bodyweight (%IBW). Ten obese children, who were treated with exercise and a low-energy diet for 1 month, were also enrolled in this study. RESULTS: The %fat, FFM and body fat content showed a close correlation when measured by BIA and DXA with the correlation coefficients being 0.90, 0.95, and 0.95, respectively. In the underweight group, the %fat value determined by BIA tended to be greater than that determined by DXA, while in the overweight group, the BIA value was lower than the DXA value. The same trend was also seen in obese children before and after therapy with exercise and diet. CONCLUSION: Bioelectrical impedance analysis seems to be a reasonable method for daily clinical use, but attention should be paid to the interpretation of %fat values in underweight and overweight children.

Absorptiometry, Photon↗

PubMed1999

Smooth muscle tumors of the esophagus: clinicopathological findings in six patients.

Preoperatively, it is difficult to discriminate leiomyoma and leiomyosarcoma of the esophagus, which are rare smooth muscle tumors. The objective of this study was to evaluate the clinicopathological findings of this unusual lesion. A search of the surgery archives of the Toyama Prefectural Central Hospital of Pathology revealed six cases of esophageal smooth muscle tumors. Clinicopathological findings were reviewed retrospectively. Only three patients (50%) presented with dysphagia, and the remaining three patients were asymptomatic. These patients underwent surgical excision. Histologically four of the six tumors were leiomyomas, and the other two tumors were leiomyosarcomas. Two tumors were in the upper to middle esophagus, and the remaining four were in the distal esophagus. On endoscopic examination, all tumors were noted to be polypoid. The two leiomyosarcomas measured over 5 cm and the four leiomyomas less than 4 cm. Neither ulceration nor necrosis proved to be of use in discriminating leiomyoma and leiomyosarcoma. The two patients with leiomyosarcoma died of liver metastasis 10 and 22 months after the treatment. Patients with leiomyosarcoma presented with distant metastasis and/or recurrence, with hematogeneous metastasis being the predominant type of recurrence.

Adult↗

PubMed1999

Number of lymph node metastases influences survival in patients with thoracic esophageal carcinoma: therapeutic value of radiation treatment for recurrence.

We retrospectively investigated whether the number of involved lymph nodes and the radiation therapy for recurrence affect survival in patients with thoracic esophageal carcinoma. Eighty-nine patients underwent surgical resection and reconstruction for thoracic esophageal squamous cell carcinoma beyond the mucosal layer. Patients were classified into three groups: group 1 comprised 40 patients without lymph node involvement; group 2 comprised 34 patients with 1-3 positive nodes; and group 3 comprised 15 patients with > or = 4 involved lymph nodes. The 3-year and 5-year survival rates were 77.5% and 73.2% respectively in group 1, 64.8% and 55.8% respectively in group 2, and 28.1% and 0% respectively in group 3. The mean survival time (MST) mean +/- SD of the patients in group 3 (772.1 +/- 146.2 days) was significantly shorter than that of patients in group 1 (3728.5 +/- 320.7 days, p < 0.0001) and group 2 (2330.4 +/- 344.3 days, p = 0.0130). The MST of the patients in group 2 was also significantly shorter than that of patients in group 1 (p = 0.0366). Patients with recurrent lymph nodes that were localized were treated effectively with radiation therapy. We conclude that the number of lymph node metastases influences survival in thoracic esophageal cancer. Early detection as well as radiation therapy for recurrent lymph node metastases is effective in improving long-term survival.

Adult↗

PubMed1999

Cystine protects cochlear outer hair cells against glutamate toxicity.

We previously reported that long-term exposure to glutamate (Glu) induced death of cochlear outer hair cells (OHCs). However, the mechanisms of OHC death induced by Glu were unclear. In the central nervous system, Glu is known to interfere with a cystine-Glu antiporter, leading to a decrease in cystine uptake and reducing the intracellular glutathione level. We therefore investigated the effect of cystine supplementation on degeneration of OHCs caused by long-term exposure to Glu. Supplementation of cystine significantly decreased the number of dying OHCs. These findings suggest that a cystine-Glu interaction may be involved in the mechanism of OHC degeneration caused by Glu.

Analysis of Variance↗

PubMed1999

Coupled map car-following model and its delayed-feedback control.

This paper proposes a coupled map car-following traffic model, which describes a dynamical behavior of a group of road vehicles running in a single lane without overtaking. This model consists of a lead vehicle and following vehicles, which have a piecewise linear optimal velocity function. When the lead-vehicle speed is varied, we can observe a traffic jam in the group of the vehicles. We derive a condition under which the traffic jam never occurs in our model. Furthermore, in order to suppress the traffic jam, for each vehicle we use a dynamic version of decentralized delayed-feedback control proposed in [Konishi, Hirai, and Kokame, Phys. Rev. E 58, 3055 (1998)], and provide a systematic procedure for designing the controller.

Journal Article↗

PubMed1999

Crystallization and preliminary x-ray diffraction studies of guanidinoacetate methyltransferase from rat liver.

Guanidinoacetate methyltransferase is the enzyme which catalyzes the last step of creatine biosynthesis. The enzyme is found ubiquitously and in abundance in the livers of all vertebrates. Recombinant rat-liver guanidinoacetate methyltransferase has been crystallized with guanidinoacetate and S-adenosylhomocysteine. The crystals belong to the monoclinic space group P2(1), with unit-cell parameters a = 54.8, b = 162.5, c = 56.1 A, beta = 96.8 (1) degrees at 93 K, and typically diffract beyond 2.8 A.

Animals↗

PubMed1999

Quasispecies of TT virus (TTV) with sequence divergence in hypervariable regions of the capsid protein in chronic TTV infection.

Three hypervariable regions were identified in a central portion of open reading frame 1 of TT virus DNA, which codes for a putative capsid protein of 770 amino acids. TT virus circulates as quasispecies, with many amino acid substitutions in hypervariable regions, to evade immune surveillance of the hosts and to establish a persistent infection.

Acute Disease↗

PubMed1999

Clinicopathological differences between colonic and rectal carcinomas: are they based on the same mechanism of carcinogenesis?

BACKGROUND: There is a difference in the location of colorectal mucosal lesions and invasive cancers. AIMS: To ascertain whether the location of colorectal neoplasms reflects the carcinogenesis pathway. METHODS: The subject material consisted of 4147 neoplastic lesions that had been resected endoscopically or surgically from 5025 patients. Mucosal lesions and submucosal cancers were classified into depressed and non-depressed types endoscopically or histologically. The relations between macroscopic type, size, histology, and location were investigated. RESULTS: (a) Non-depressed type. A total of 1774 of 3454 (51%) mucosal lesions were located in the right colon, 1212 (35%) in the left colon, and 468 (14%) in the rectum. The incidence of mucosal lesions larger than 10 mm was 10% (185/1774) in the right colon, 21% (254/1212) in the left colon, and 27% (127/468) in the rectum. The incidence of mucosal lesions with villous components was 2% (32/1774) in the right colon, 5% (63/1212) in the left colon, and 13% (62/468) in the rectum. The ratio of submucosal cancers to mucosal lesions was significantly higher in the rectum (0.064, 30/469) than in the left (0.034, 43/1279) or right (0.010, 18/1857) colon. (b) Depressed type. The incidences of depressed type mucosal lesions and submucosal cancers were 5% (83/1857) and 17% (3/18) in the right colon, 5% (67/1279) and 5% (2/43) in the left colon, and 0.2% (1/469) and 0% (0/30) in the rectum, respectively. CONCLUSION: There may be some mechanisms that promote the progression of mucosal lesions to invasive cancers in the left colon and rectum, whereas a de novo pathway from depressed type lesions may be implicated in some cancers of the right colon.

Adenoma↗

PubMed1999

Highly aggressive behavior and poor prognosis of small-cell carcinoma in the alimentary tract: flow-cytometric analysis and immunohistochemical staining for the p53 protein and proliferating cell nuclear antigen.

The purpose of this study was to determine the clinical course, and effects of the histopathologic characteristics of specific tumors, including DNA contents and immunohistochemical aspects, in patients with small-cell carcinoma of the alimentary tract. Medical records of 14 patients who presented with small-cell carcinoma of the alimentary tract were retrospectively reviewed. Primary tumors were studied by immunohistochemical and flow cytometric analyses. Of these 14 small-cell carcinomas, 4 were esophageal, 8 gastric, and 2 colonic tumors. DNA aneuploidy was observed in 8 tumors. Staining for the p53 product was positive in 57.1% of all the tumors. The average proliferating cell nuclear antigen (PCNA) labeling rate (LR) was 72.4 +/- 11.6%. The average PCNA LR was significantly higher for the p53-positive group (p < 0.05). The estimated median survival was 253 days for all patients. Noncurative resection was associated with a significantly less favorable prognosis (p < 0.01). Distant metastases were observed in 13 of 14 patients. A higher PCNA LR of small-cell carcinoma may be an unfavorable characteristic of biological behavior. The patients with disseminated disease should undergo a symptomatically palliative operation combined with chemotherapy.

Adult↗

PubMed1999

Esophageal sarcomas: report of three cases.

BACKGROUND/AIMS: Sarcomas of the esophagus, including carcinosarcoma, are rare neoplasms. METHODS: The clinical and pathologic characteristics of 3 patients with esophageal sarcomas are presented, including the only recorded esophageal carcinosarcoma and 2 patients with leiomyosarcoma. RESULTS: All 3 patients were males who presented with dysphagia or an abnormal shadow of the mediastinum on a plain chest X-ray. Two tumors were in the middle esophagus, and the remaining one was in the distal esophagus. On endoscopic examination, all three tumors were noted to be polypoid. These patients underwent surgical excision. One patient died 7 days following the operation, and the remaining 2 patients died of liver metastasis 10 and 22 months following the treatment. CONCLUSION: Esophagectomy or esophagogastrectomy is a surgical choice. Even if metastases are present, a palliative resection can still be performed.

Aged↗

PubMed1999

Association of a novel 3-amino acid deletion mutation of apolipoprotein E (Apo E Tokyo) with lipoprotein glomerulopathy.

Lipoprotein glomerulopathy (LPG) is a newly recognized renal disease characterized by abnormal lipoprotein deposition in the glomeruli, dysbetalipoproteinemia, and a high level of plasma apolipoprotein (apo) E. We identified a novel apo E mutation in a 56-year-old Japanese male with LPG. Although the plasma cholesterol and triglyceride levels were normal, the levels of intermediate-density lipoprotein cholesterol and apo E were elevated to 13 mg/dl (0.336 mmol/l; 4.2+/-2.9 mg/dl, mean +/- SD, in 12 normolipidemic controls) and 9.2 mg/dl, respectively. Biochemical analysis revealed an unusual apo E phenotype (E1/3). Apo E genotyping using DNA digested by a restriction enzyme (HhaI) identified a 66-bp fragment which was not seen with any of the common alleles. Sequence analysis of the amplified genomic DNA fragments showed a 9-bp deletion in exon 4 of the apo E gene resulting in a 3-amino acid deletion (residues 141-143). This novel mutation involves the region of the apo E molecule known to be critically involved in binding to its receptor, and this may well transform the apo E molecule, an inefficient ligand, to its receptor(s). How this mutations causes glomerular damage remains to be determined.

Apolipoproteins E↗

PubMed1999

Inhibitory effects of tannins on the NADH dehydrogenase activity of bovine heart mitochondrial complex I.

NADH-quinone oxidoreductase is classified into two groups, NADH dehydrogenase-1 (NDH-1) and NADH dehydrogenase-2 (NDH-2). Animal mitochondrial complex I is an NDH-1 type enzyme. Previously, we isolated potent inhibitors from plants to both NDH-1 and NDH-2. We have now examined detailed inhibitory effects of three tannins (pentagalloylglucose, sanguiin H-11, and oolonghomobisflavan A) on NDH-1 using bovine heart mitochondrial complex I and a subcomplex flavoprotein (containing 3 subunits) derived from complex I. Although many specific inhibitors of NDH-1 (e.g. rotenone and piericidin A) have been reported, the reactive sites are at or near to, the ubiquinone-binding site. NADH-ubiquinone-1 oxidoreductase activity of complex I was inhibited by the three tannins, among which sanguiin H-11 was the most potent inhibitor. NADH-menadione oxidoreductase activity of complex I was susceptible to the three tannins, but completely resistant to rotenone. The inhibitory effects of tannins were all noncompetitive with respect to NADH, ubiquinone-1, and menadione. The NADH-menadione oxidoreductase of flavoprotein was also inhibited by the three tannins, but not by rotenone, which is consistent with the fact that flavoprotein does not contain a native ubiquinone-binding site. The study of the NADH reduced-minus-oxidized difference spectrum of flavoprotein under steady-state conditions indicated that the inhibitory sites of sanguiin H-11 and oolonghomobisflavan A exist between the NADH binding site and the FMN site, and that for pentagalloylglucose exists between FMN and an artificial electron acceptor-binding site. These results suggest that the tannins are potent inhibitors of NADH dehydrogenases, and that the inhibitory mechanisms are novel.

Animals↗

PubMed1999

Effects of angiotensin inhibitors on renal injury and angiotensin receptor expression in early hypertensive nephrosclerosis.

Angiotensin converting enzyme inhibitors (ACEI) are known to inhibit the progression of established renal failure. The aim of this study was to compare the efficacy of an ACEI and an AT1 receptor antagonist (AT1R-Ant) in preventing the development of renal disease, at an early stage of hypertensive nephrosclerosis. SHRSP/Izm rats (n = 61) were treated from 10 wk until 22 wk with the ACEI delapril (40 mg/kg/d) or the AT1R-Ant candesartan cilexetil (1 mg/kg/d). Proteinuria, and structural/ultrastructural changes were assessed at 14 and 22 wk. Treatment with either agent resulted in reductions in blood pressure and cardiovascular hypertrophy. Neither proteinuria nor major renal histological changes were evident at 14 wk. At 22 wk, however, proteinuria accompanied by nephrosclerotic changes was seen in the untreated SHRSP/Izm. Treatment with either ACEI or AT1R-Ant resulted in similar reductions in proteinuria (untreated, 32.2 +/- 7.4; delapril-treated, 5.5 +/- 1.2; candesartan-treated, 3.9 +/- 0.3 mg/100 g/d). Prominent sclerosis of small-to-medium sized renal arteries was seen in the untreated SHRSP/Izm at 22 wk, but was similarly attenuated by the ACEI and AT1R-Ant. The glomerular ultrastructure was comparable between the two groups. No significant changes in renal AT1a or AT1b receptor subtype mRNA expression were seen throughout the course of the study. In contrast, a decrease in AT2 receptor mRNA was seen in the drug-treated groups at 14 wk but not at 22 wk. These results suggest that both ACEI and AT1R-Ant have similar efficacy in attenuating the onset of renal injury in early hypertensive nephrosclerosis, and that treatment with either agent is associated with a transient decrease in AT2 receptor mRNA expression.

Angiotensin Receptor Antagonists↗

PubMed1999

[Involvement of TTV, a new infectious factor in post-transfusion hepatitis, non A-non G].

Post-transfusion hepatitis developed in 6 of 447(1.3%) patients who received transfusion even after 1992 when HCV screening by PHA method was started. The six patients were suggested as hepatitis, non-B, non-C, non-G type. Of the six patients, 4 were found to be infected with TTV, which was identified in one of the patients. The patients became positive for TTV DNA before or almost the same time as the development of hepatitis and their amounts of TTV DNA were varied depending on the ALT level, suggesting that their hepatitis might be caused by TTV. The patients who presented hepatitis became positive for TTV DNA in the 6-10th week after transfusion, whereas more than half of the patients with a slight hepatic disorder became positive in the 2-4th week after transfusion. In addition, prolonged infection with TTV was only observed in nearly half of 23 patients.

Biomarkers↗

PubMed1999