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Biomedical subjects

K Mochizuki

Publications and source records attributed to K Mochizuki.

At least 37 records · Page 2Linked to original sources
PubMed2001

[A case of enucleation for multiple renal cell carcinomas in unilateral kidney with microwave tissue coagulator].

A 67-year-old man, who had undergone left nephroureterectomy for ureteral tumor (transitional cell carcinoma, G1) eight years previously, was found to have two renal tumors in the residual right kidney by the follow-up computed tomography (CT). We performed non-ischemic enucleation for multiple tumors at the upper and lower pole in the unilateral kidney using a microwave tissue coagulator (MTC). We confirmed by means of ultrasonography during operation the absence of any other satellite tumors. The operation time was 154 minutes and bleeding during operation was 267 ml. There was no difference between creatinine before (0.73 mg/dl) and after (0.79 mg/dl) operation. On the follow-up CT, there was a low density area after enucleation. This area gradually decreased and disappeared on enhanced CT 18 months after operation. We enucleated multiple renal cell carcinomas using MTC without reduction of renal function or remarkable side effects. These results suggested that non-ischemic enucleation using MTC would be useful for multiple renal cell carcinoma in the unilateral kidney.

Aged↗
PubMed2001

Fast MR imaging and ultrafast MR imaging of fetal central nervous system abnormalities.

The aims of this study were two: (1) to compare the efficacy of fast MRI (breath-hold fast spin-echo T2-weighted and fast gradient-echo T1-weighted sequence) and ultrafast MRI (half-Fourier acquisition single-shot turbo spin-echo sequence) in evaluation of fetal central nervous system (CNS) abnormalities at late gestational age, and (2) to compare the capability of fast MRI and ultrafast MRI to assess fetal CNS abnormalities with that of prenatal ultrasonography (US). Forty-nine women with fetuses at gestational ages of 26-39 weeks underwent fast MRI (29 patients) or ultrafast MRI (20 patients). In detection of motion artifact, visualization of the lateral and 4th ventricles, and differentiation between gray and white matter in cerebral hemispheres, ultrafast MRI was significantly superior to fast MRI (p< 0.0001, Mann-Whitney U test). In 25 of 43 cases, US and MR diagnoses were the same and consistent with postnatal diagnosis. In 10 of 43 cases, MRI demonstrated findings additional to or different from those of US, and MR findings were confirmed postnatally. MRI, particularly ultrafast MRI, is useful for demonstrating CNS abnormalities in situations in which US is suggestive but not definitive.

Anencephaly↗
PubMed2000

The management of pelvic chondrosarcoma in Japan. Japanese Musculo-Skeletal Oncology Group.

A review of 135 patients with pelvic chondrosarcoma who had been treated at 58 institutions in Japan between 1989 and 1998. In this series ablative surgery was necessary in 14 patients, and a limb salvage procedure performed in 121 patients. The surgical margins were "intra-lesional" in 27 patients, "marginal" in 30, "wide" in 77 and "unspecified" in 1. Local recurrence occurred in 33 patients and distant metastases in 25. Post-operative infection occurred in 25 patients. Revision was performed in 10 patients. The oncological outcome was "disease free" in 92 patients, "alive with disease" in 17 and "dead because of the disease" in 26. The cumulative prospective 10-year survival rate for all patients was 65%. The 6 statistically significant prognostic factors that determined the outcome were: - surgical stage, site of tumour, size of tumour, surgical margin, functional mobility and activity level after surgery. Excision of the tumour with a wide margin, or with a wide margin with partly marginal areas, and subsequent stable reconstruction are essential for improving the results of pelvic chondrosarcoma treatment.

Acetabulum↗
PubMed2000

Expression and evolutionary conservation of nanos-related genes in Hydra.

The Drosophila gene nanos encodes two particular zinc finger motifs which are also found in germline-associated factors from nematodes to vertebrates. We cloned two nanos (nos)-related genes, Cnnos1 and Cnnos2 from Hydra magnipapillata. Using whole-mount in situ hybridization, the expression of Cnnos1 and Cnnos2 was examined. Cnnos1 was specifically expressed in multipotent stem cells and germline cells, but not in somatic cells. Cnnos2 was weakly expressed in germline cells and more specifically in the endoderm of the hypostome where it appears to be involved in head morphogenesis. In addition to structural conservation in the zinc finger domain of nanos-related genes, functional conservation of Cnnos1 was also demonstrated by the finding that a Cnnos1 transgene can partially rescue the nosRC phenotype that is defective in the egg production of Drosophila. Thus, the function of nanos-related genes in the germline appears to be well conserved from primitive to highly evolved metazoans.

Amino Acid Sequence↗
PubMed2000

Effect of salmon calcitonin on experimental osteoporosis induced by ovariectomy and low-calcium diet in the rat.

To investigate the action and effect of calcitonin on osteoporosis, this study was performed in osteoporotic rats that had been ovariectomized and maintained on a low-calcium diet. Significant bone loss was noted in ovariectomized rats compared with those that underwent sham surgeries, and histological findings proved bone turnover to be increased. In comparison with this osteoporotic rat group, those given calcitonin showed less bone loss; the reduction in bone loss was obvious in the vertebral body, and rats given a high dose of calcitonin over a long duration showed even less bone loss, but this was hardly seen in the proximal tibial metaphysis. Histological findings proved that calcitonin inhibited the bone resorption that was stimulated by the ovariectomy. Values for osteoblast surfaces were relatively higher while those of reversal surfaces were lower. The results confirm that salmon calcitonin has an inhibitory action on bone resorption as well as being effective in maintaining and stimulating bone formation in vivo. These effects of calcitonin prevented progress of the osteoporosis that had been induced by ovariectomy, and the effects appeared differently in each region.

Aging↗
PubMed2000

Seventeen-year follow-up of massive osteolysis of the scapula.

A 14-year-old boy with massive osteolysis of the right scapula was treated by irradiation with a total dose of 58 Gy, using cobalt 60 (2 Gy per fraction) in 1983 and 1984. Histopathology in a biopsy specimen revealed hemangiomatosis associated with few osteoclasts and a lining of oval or spindle-shaped endothelial-like cells. The osteolysis has been interrupted since the last irradiation. In January 2000, 17 years after the initial treatment, the patient is working as a public officer, and shows no clinical signs of postradiation sarcoma. Radiographs show a residual scapula with sclerotic margin, associated with marked hypoplasia and atrophy of the right humerus. Ranges of motion of the right shoulder are 100 degrees on anterior elevation, 40 degrees on posterior elevation, and 70 degrees on abduction. The patient experiences no problems in daily living, except for difficulty in lifting.

Adolescent↗
PubMed2000

Clinical characteristics of patients with chronic hepatitis C showing biochemical remission, without hepatitis C virus eradication, as a result of interferon therapy. The Osaka Liver Disease Study Group.

During long-term follow-up of patients chronically infected with the hepatitis C virus (HCV) and treated with interferon (IFN), we identified some who had persistent normalization of serum alanine aminotransferase (ALT) but remained positive for HCV RNA. The aims of this study were to clarify the characteristics of these patients and to examine their clinical outcome after treatment. Nine hundred and ninety-eight patients treated with IFN were followed-up biochemically and virologically, and by liver ultrasound, for 13-95 months. A short-term biochemical sustained response, where ALT remained within the normal range for 6 months after the completion of IFN therapy, was found in 296 patients; in 240 of these patients serum HCV RNA remained undetectable during long-term follow-up. The rate of HCV RNA persistence was 7.09 times greater in short-term biochemical sustained responders with a high viral load than in those with a low viral load (P=0.0001, odds ratio [OR]=7.09), and 3. 70-fold lower in those treated with a large dose of IFN than in those treated with a small dose (P=0.02, OR=0.27). Thirty-three (59%) of 56 patients without HCV eradication showed continuous ALT normalization for 26-80 months after cessation of IFN therapy. Short-term biochemical sustained responders who were older (P=0.009, OR=10.43) and who were male (P=0.03, OR=6.98) had a significantly greater probability of maintaining a normal ALT level, even when serum HCV RNA was positive. When the incidence of HCC was investigated during long-term follow-up in patients without HCV eradication, it was found to be significantly lower in patients with persistently normal ALT levels than in those with abnormal ALT levels (P=0.03). Hence, when HCV is not eradicated as a result of IFN therapy, it may induce a long-term carrier state of HCV infection with normal ALT levels in older or male patients, in whom the cumulative incidence of HCC is markedly decreased.

Adult↗
PubMed2000

Probability of hepatocellular carcinoma of small hepatocellular nodules undetectable by computed tomography during arterial portography.

Recent advances in imaging modalities enable the identification of small hepatocellular nodules. Among the imaging techniques currently used for detecting hepatocellular carcinomas (HCC), computed tomography (CT) during arterial portography (CTAP) is one of the most sensitive techniques available for detecting hemodynamic change. Even so, well-differentiated HCCs that display only limited hemodynamic change, a feature shared with nonmalignant hepatocellular nodules, are not always detectable by CTAP. To improve our ability to distinguish well-differentiated HCCs from nonmalignant hepatocellular nodules, we have attempted to clarify how the characteristics of the nodules are shown by each imaging technique. We studied the imaging and pathological characteristics of 31 nodules (in 22 patients) detected by ultrasonography (US), but not by CTAP. Histological diagnoses were as follows: HCC, 17 of 31 nodules (55%); high-grade dysplastic nodules, 1 of 31 (3%); and nonmalignant nodules, 13 of 31 (42%). Neither digital substraction angiography (DSA) nor CT arteriography (CTA) were able to detect any of the nodules. Detection rates for plain CT were: 5 of 17 (29%) HCC, 1 of 1 (100%) high-grade dysplastic nodules, and 1 of 13 (8%) nonmalignant nodules. Detection rates for T1/T2-weighted magnetic resonance imaging (MRI) were: 4 of 17 (24%) HCC, 1 of 1 (100%) high-grade dysplastic nodules, and 3 of 13 (23%) nonmalignant nodules. Dynamic CT and dynamic MRI provided no additional information. In conclusion, there is some probability that hepatocellular nodules detected by US, but not by CTAP, are HCC. Presently, it is difficult to distinguish between benign nodules and malignant ones with these imaging techniques, and our findings indicate that biopsy may be advisable for nodules detected under these conditions.

Adult↗
PubMed2000

Synthesis of 2,2,4,4-tetramethyl-N,N'-bis(2,6-dimethylphenyl)cyclobutane-1,3-diimine , a unique compound from Arundo donax, and its analogues to test their antifeedant activity against the boll weevil, Anthonomus grandis.

2,2,4,4-Tetramethyl-N,N'-bis(2,6-dimethylphenyl) cyclobutane-1,3-diimine (1), which was isolated from the Thai plant Arundo donax as an antifeedant against the boll weevil (Anthonomus grandis), and its analogues (9-13) were synthesized and shown to possess no remarkable antifeedant activity of practical interest.

Animals↗
PubMed1999

Transcriptional regulation of cellular retinol-binding protein, type II gene expression in small intestine by dietary fat.

We have previously demonstrated that dietary fat, especially unsaturated fatty acids, induces cellular retinol-binding protein, type II (CRBPII) gene expression in rat jejunum. In the present study, we showed that feeding a high-fat diet caused parallel increases in jejunal CRBPII mRNA and CRBPII pre-mRNA levels. Nuclear run-on assay also revealed that this increase of CRBPII mRNA level by high-fat diet was, at least in part, triggered at a transcription level. Moreover, peroxisome proliferator-activated receptor alpha (PPARalpha) mRNA level was also increased in the jejunum by high-fat diet. Gel shift assay showed that the binding activity of rat jejunal nuclear protein to the nuclear receptor response elements located in the rat CRBPII gene (RXRE and RE3) was greater in rats fed high-fat diet than in those fed fat-free diet and were enhanced by addition of bacterially expressed PPARalpha protein. Also PPARalpha-retinoid X receptor alpha (RXRalpha) heterodimer was capable of binding to the CRBPII-RXRE and RE3 elements and these binding activities were enhanced by addition of some PPARalpha ligands in the gel shift assay. Taken together, these studies suggest that dietary fatty acids may lead to induction of CRBPII gene transcription through increases of PPARalpha as well as its ligand levels.

Animals↗
PubMed1999

Purification and characterization of 5-oxo-L-prolinase from Paecilomyces varioti F-1, an ATP-dependent hydrolase active with L-2-oxothiazolidine-4-carboxylic acid.

An enzyme cleaving L-2-oxothiazolidine-4-carboxylic acid to L-cysteine was purified 75-fold with 8% recovery to near homogeneity from crude extracts of Paecilomyces varioti F-1, which had been isolated as a fungus able to assimilate L-2-oxothiazolidine-4-carboxylic acid. The molecular mass was estimated to be 260 kDa by gel filtration. The purified preparation migrated as a single band of molecular mass 140 kDa upon SDS-PAGE. The maximum activity was observed at a range of pH 7.0-8.0 and at 50 degrees C. The enzyme activity was completely inhibited by SH-blocking reagents such as AgNO(3), p-chloromercuribenzoic acid, N-ethylmaleimide, and N-bromosuccinimide. The enzyme required ATP, Mg(2+), and KCl for the cleavage of L-2-oxothiazolidine-4-carboxylic acid. The enzyme also cleaved 5-oxo-L-proline to L-glutamic acid and is considered to be 5-oxo-L-prolinase.

Amidohydrolases↗
PubMed1999

Regulation of cellular retinol-binding protein type II gene expression by arachidonic acid analogue and 9-cis retinoic acid in caco-2 cells.

We previously showed that unsaturated fatty acids induced gene expression of cellular retinol-binding protein type II (CRBPII) in rat jejunum [Suruga, K., Suzuki, R., Goda, T. and Takase, S. (1995) J. Nutr. 125, 2039-2044]. In the present study, we investigated this induction mechanism(s) using the human intestinal Caco-2 cell line. The postconfluent mature Caco-2 cells were maintained in serum-free medium containing arachidonic acid or its analogue, 5,8,11, 14-eicosatetraynoic acid (ETYA). Northern blot analysis showed that these compounds induced CRBPII mRNA levels to rise and that this induction was more effective when combined with 9-cis retinoic acid. This effect was independent of cycloheximide and inhibited by actinomycin D. Nuclear run-on assays confirmed that the ETYA and 9-cis retinoic acid-induced increase of CRBPII mRNA levels was due to an increased rate of transcription of its gene. In Caco-2 cells, the transcripts of peroxisome proliferator-activated receptor alpha (PPARalpha) and retinoid X receptor alpha (RXRalpha), which were activated by their ligands ETYA and 9-cis retinoic acid, respectively, were coexpressed. The gel shift study using rat CRBPII gene nuclear receptor response elements (RXRE, RE2, RE3) revealed that several forms of nuclear proteins from Caco-2 cells specifically bound to these elements. Some of these protein/DNA complexes reacted to both anti-RXRalpha and anti-PPAR antibodies. In addition, in-vitro synthesized RXRalpha and PPARalpha cooperatively bound to these elements as a heterodimer and these binding activities were enhanced by addition of ETYA or arachidonic acid but not by addition of 9-cis retinoic acid. These studies suggest that fatty acid or its analogue may regulate CRBPII gene expression through PPAR/RXR heterodimer bound to the nuclear receptor response element(s) of the CRBPII genes.

Alitretinoin↗
PubMed1999

The normal development of Mongolian gerbil foetuses and, in particular, the timing and sequence of the appearance of ossification centres.

To elucidate the normal development and growth of Mongolian gerbils, the timing and sequence of the appearance of ossification centres within foetuses were investigated. Average foetus body weight and tail length on the 15th day of pregnancy were found to be 0.042 g and 6.2 mm, respectively. For the 25th day of pregnancy, these measurements were 2.601 g and 29.4 mm, respectively. The body weight and tail length of foetuses increased significantly from the 20th day of pregnancy. Also, the first ossification centre of Mongolian gerbil foetuses appeared in the clavicle at the 17th day of pregnancy. The order in which ossification centres appeared in Mongolian gerbils resembles the pattern for rats and mice, except in some areas of the skull. Except for the clavicle, in which ossification centres appeared rather early, most ossification centres appeared in the last quarter of pregnancy. These results suggest that Mongolian gerbil foetal development is near completion by the last gestational stage. Also, ossification centres appear sooner in the skull and nasal bones than in other rodents.

Animals↗
PubMed1999

Quantitative anhydrous mercaptolysis of algal galactans followed by HPLC of component sugars.

This paper describes a new HPLC method for the sugar analysis of algal galactans containing 3,6-anhydrogalactose, which is readily destroyed during usual acid hydrolysis and methanolysis. By anhydrous mercaptolysis of galactans at 60 degreesC for 6 h with the newly developed solvent system, 0.5 N HCl/[ethanethiol:methanol (2:1, v/v)], component sugars, including 3,6-anhydrogalactose, were liberated quantitatively as their diethyl dithioacetals. The resultant sugar diethyl dithioacetals were found to have strong UV-absorption (absorption maximum of 3,6-anhydrogalactose diethyl dithioacetal in water, 191-192 nm; molar extinction coefficient, 4,400). The sugar diethyl dithioacetals were then resolved simultaneously within 15 min by reversed phase HPLC with 30% acetonitrile as the eluent and detected by UV-absorption at 215 nm. Amounts of sugar diethyl dithioacetals less than 50 pmol can be determined without further derivatization.

Absorption↗
PubMed1999

Enhancement of LPS-stimulated plasminogen activator production in aged gingival fibroblasts.

Plasminogen activator (PA) converts plasminogen to plasmin, and plasmin activates the kinin cascade and latent methalloproteases. It is known that the alteration of the PA-plasmin system affects the progression of periodontal disease. We have reported previously that LPS from Campylobacter rectus, which is associated with adult periodontitis, increased PA production in human gingival fibroblasts (hGF). The effects of in vitro- and in vivo-cellular ageing on PA production from human and rat gingival fibroblasts (rGF) were studied. In vitro cellular aged hGF were prepared by subcultivations of hGF, and in vivo aged rGF was cultured primarily from the gingival tissue of aged rats. The cells were challenged with LPS and PA released into the cultured medium was measured as PA activity. Both in vitro and in vivo cellular aged GFs produced a significantly higher PA activity by LPS compared with young GFs cell. In RT-PCR experiments, tissue type PA (tPA) mRNA levels in both aged hGF and rGF were higher than in young cells, whereas plasminogen activator inhibitor 1 (PAI-1) mRNA remained unchanged and urotype PA (uPA) mRNA was not detected. Since LPS-stimulated PA activity from gingival fibroblasts was stimulated in aged cells using both in vitro- and in vivo-experimental models, the ageing of gingival fibroblasts may have an effect on the severity of inflammation and degradation of the extracellular matrix of gingival tissues by producing a large amount of PA in response to LPS.

Animals↗
PubMed1999

T134, a small-molecule CXCR4 inhibitor, has no cross-drug resistance with AMD3100, a CXCR4 antagonist with a different structure.

T22, an analog of polyphemusin II (18 amino acid residues), was found to block T-tropic human immunodeficiency virus type 1 (HIV-1) entry into target cells as a CXCR4 inhibitor. We synthesized T134, a small analog (14 amino acid residues) of T22 with reduced positive charges. T134 exhibited highly potent activity and significantly less cytotoxicity in comparison to that of T22. T134 prevents the anti-CXCR4 monoclonal antibody from binding to peripheral blood mononuclear cells but has no effect on the binding of anti-CCR5 monoclonal antibodies. Since T134 inhibits the binding of stromal cell-derived factor-1 (SDF-1) to MT-4 cells, it seems that T134 prevents HIV-1 entry by binding to CXCR4. The bicyclam AMD3100 has also been shown to block HIV-1 entry via CXCR4 but not via CCR5. Both T134 and AMD3100 are CXCR4 antagonists and low-molecular-weight compounds but have different structures. Our results indicate that T134 is active against wild-type T-tropic HIV-1 strains and against AMD3100-resistant strains.

Anti-HIV Agents↗
PubMed1999

The horizontally impacted maxillary canine situated in a labial position.

Surgical management of unerupted teeth depends upon a thorough understanding of anatomic, physiologic and pathologic factors. Attention has been given to problems of eruption in the maxillary anterior region. It is a region where a variety of anomalies occur. Since the maxillary anterior region influences appearance so greatly, early detection of difficulties and careful planning and treatment can be extremely beneficial to patients. The purpose of this case report is to present a case of maxillary permanent canine impaction in a horizontal displacement that developed after loss of the deciduous canine to chronic apical periodontitis, and incomplete root resorption of the deciduous canine.

Child↗