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Biomedical subjects

S Uchida

Publications and source records attributed to S Uchida.

At least 181 records · Page 10Linked to original sources
PubMed1999

In vitro B-mode ultrasonographic criteria for diagnosing axillary lymph node metastasis of breast cancer.

Axillary lymph node status is an important factor for staging and treatment planning in breast cancer. Our study was performed in vitro on a node-by-node basis to evaluate the ability of B-mode ultrasonographic images to distinguish metastatic from nonmetastatic nodes. Immediately prior to histologic examination, individual dissected axillary nodes were scanned in a water bath using a 10 MHz B-mode ultrasonographic transducer. Four B-mode features (size, circularity, border demarcation, and internal echo) were evaluated for their ability to distinguish metastatic from nonmetastatic lymph nodes. Lymph node metastasis was indicated by (1) a large size (i.e., a length of the longest axis of 10 mm or greater); (2) a circular shape (i.e., the ratio of the shortest axis to the longest axis between 0.5 and 1.0); (3) a sharply demarcated border compared with surrounding fatty tissue; and (4) a hypoechoic internal echo, with obliteration of the fatty hilum. The sensitivity and specificity were compared for all combinations of features. We examined 84 histologically characterized axillary nodes from 27 breast cancer patients, including 64 nonmetastatic and 20 metastatic nodes. Of the criteria cited, circular shape was the best single feature for distinguishing metastatic from nonmetastatic nodes (sensitivity, 65%; specificity, 73%). The best combination of sensitivity (85%) and specificity (73%) was obtained using the criterion that a lymph node contained cancer when at least three positive features were present. The present in vitro study demonstrated that the sensitivity and specificity of B-mode ultrasonography for diagnosing lymph node metastasis were lower than 90%. Therefore, B-mode ultrasonography may not be an optimal noninvasive screening method for diagnosing axillary lymph node metastasis in breast cancer patients, particularly under in vivo clinical conditions.

Adult↗
PubMed1999

Implication of vascular endothelial growth factor in the development and metastasis of human cancers.

Vascular endothelial growth factor (VEGF) is a most potent angiogenic molecule. In this article, we demonstrated that VEGF is participated in the tumor angiogenesis of hepatocellular carcinoma, esophageal cancer, and pancreatic cancer. Furthermore, we revealed that VEGF is one of the molecules which are responsible for metastasis and prognosis in esophageal cancer and colon cancer. Although the mechanism on the induction of VEGF gene is still unclear in human cancer tissue, we obtained the informative evidence indicating that p53 mutation is involved in VEGF expression of esophageal cancer. Our experimental study with stable transfectant of VEGF gene provided the confirmative results showing that VEGF gene induces neovascularization in and around tumor and that VEGF augment metastastic potential by accelerating proliferative activity after reaching the target organ.

Cell Transformation, Neoplastic↗
PubMed1999

[Marked hypernatremia in suprasellar germinoma lacking a sense of thirst].

We here report a 17-year-old high school boy having suprasellar germinoma who presented marked hypernatremia probably due to damages of both the osmoregulation and thirst centers. He was in good health until July, 1996, when he noticed slight general malaise and complained of dryness of the mouth, but without polyuria. He was found to have hypernatremia of mild degree (serum Na 151 mEq/l), but dropped out from the follow-up. In April, 1997, he was admitted to our hospital with complaints of general malaise and weakness of the upper and lower extremities. Serum Na was high at 202 mEq/l with a plasma osmolality of 390 mOsm/kg H2O. He completely lacked a sense of thirst and polydipsia/polyuria. Computed tomography and magnetic resonance imaging indicated a suprasellar tumor, possibly a germinoma. Hypernatremia was first treated with intravenous infusion of a half-normal saline solution, followed by immediate polyuria of 3 to 6 l/day. Subsequently, nasal administration of desamino-D-arginine vasopressin (DDAVP) induced stabilization of serum Na to a range between 140 and 160 mEq/l. The tumor disappeared following steroid pulse therapy and irradiation of 50 Gy to the brain. At the time of discharge, he and his family were instructed to record the urine volume, amount of water intake, body weight and amount of DDAVP used. The patient was instructed to drink water corresponding to the urine volume while maintaining the dose of DDAVP. One year after treatment, the water balance reverted to a positive direction, leading to a normal range of serum Na probably because of partial recovery of the osmoreceptors and/or trained drinking habit. This case illustrates the so-called adipsic hypernatremia which is attributed to partial osmoreceptor destruction by a suprasellar germinoma.

Adolescent↗
PubMed1998

Transfusion-associated graft-versus-host disease in immunocompetent patient: early diagnosis and therapy.

We report a case of transfusion-associated graft-versus-host disease in a previously healthy, 68-year-old Japanese man following an emergency surgery for an acute aortic dissection. We confirmed the chimerism of lymphocytes and the effect of drug therapy using DNA polymorphism analysis. This method is a sensitive, convenient, and rapid method that it is also useful for the evaluation of therapy. And the combination therapy with methylprednisolone, cyclosporine, and 15-deoxyspergualin may be effective in treating transfusion-associated GVHD.

Aged↗
PubMed1998

Benzodiazepine effects on human sleep EEG spectra: a comparison of triazolam and flunitrazepam.

The effects of 0.5 mg triazolam (TRI) and 4 mg flunitrazepam (FNZ) on the sleep electroencephalogram (EEG) were studied in eleven (six for TRI, and five for FNZ) healthy young male subjects. C3 EEG channel data of one baseline night, three drug nights and two withdrawal nights were recorded and their analyzed using a fast Fourier transformation (FFT) method. Changes in the 0.5 Hz to 40 Hz power spectrum showed that: 1) both TRI and FNZ increased higher frequency activity and reduced lower frequency activity on the drug nights; 2) on drug nights, NREM sigma frequency power was more strongly enhanced by TRI than FNZ, while the beta power of both NREM and REM was more strongly enhanced by FNZ than TRI; 3) NREM alpha power increased on the second night of withdrawal from both TRI and FNZ; 4) the power spectra for both NREM and REM sleep returned to baseline levels by the fourth night of withdrawal from either TRI or FNZ. These findings suggest that 0.5 mg TRI and 4 mg FNZ have both common and differing pharmacological effects on the central nervous system. Such differences could be caused by differences in the dose, half-life or systemic distribution of these two drugs.

Adult↗
PubMed1998

Coating of CaTiO3 on titanium substrates by hydrothermal reactions using calcium-ethylene diamine tetra acetic acid chelate.

Titanium plates were treated in [Ti(O2)EDTA]2- -Ca(EDTA)2- mixed solutions and/or Ca(EDTA)2- solutions (where EDTA is ethylene diamine tetra acetic acid) at pH 9-13 and 150-250 degrees C for 0.5-12 h. The film, about 50 microm thick, and consisting of mixtures of CaTiO3 and TiO2 was formed in 0.01 M [Ti(O2)EDTA]2- - 0.01 M Ca(EDTA)2- mixed solution at pH 13 and 250 degrees C for 6 h. The film consisted of large icosahedral and hexagonal particles, of about 10 microm diameter, and small aggregated particles, of about 1 microm diameter. On the other hand, the film, about 20 microm thick, consisted of hexagonal plate-like CaTiO3 particles, of about 1 microm diameter, was formed in 0.01 M Ca(EDTA)2- solution at pH 13 and 250 degrees C for 6 h. The thickness of both films increased with time, where the film formation rate in 0.01 M [Ti(O2)EDTA]2- - 0.01 M Ca(EDTA)2- mixed solution was much faster. The CaTiO3 film formed on the surface of titanium promoted the precipitation of hydroxyapatite on the substrate by the hydrothermal reactions in Ca(EDTA)2- -PO(4)3- mixed solutions.

Journal Article↗
PubMed1998

In oesophageal squamous cell carcinoma vascular endothelial growth factor is associated with p53 mutation, advanced stage and poor prognosis.

Vascular endothelial growth factor (VEGF) affects malignant tumours by promoting angiogenesis. The tumour-suppressor gene p53 has been thought to regulate VEGF. We investigated the effect of VEGF on oesophageal carcinoma and the connection between VEGF and p53. One hundred and nine resected oesophageal squamous cell carcinomas were examined. VEGF expression was analysed by immunohistochemical staining. Sixty-five tumours (59.6%, 65 out of 109) were classified as VEGF positive. A significant correlation was found between the VEGF expression and both the depth of invasion (P = 0.0001) and lymph node metastasis (P < 0.0001). With regard to p53, we compared the expression of VEGF with the mutation of p53, examined using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct sequencing in tumour samples obtained from 36 patients who we have reported previously. The VEGF expression was significantly correlated to p53 mutation (P = 0.0291). To evaluate the angiogenesis, microvascular density (MVD) was counted, and endothelial cells were stained immunohistochemically using anti-CD34 monoclonal antibody against 29 cases with invasion limited to the submucosal layer. The average MVD had a tendency to correlate to VEGF expression (P = 0.1626). The prognoses of patients with VEGF-positive primary tumours were significantly worse than for those with VEGF-negative primary tumours (P = 0.0077). We have assumed that VEGF contributes to aggressive characteristics in oesophageal carcinomas and that VEGF expression might be affected by p53 status.

Carcinoma, Squamous Cell↗
PubMed1998

Dispersion of regional wall motion abnormality in patients with long QT syndrome.

OBJECTIVE: To examine the left ventricular regional wall motion abnormality and to evaluate dispersion of this abnormality in patients with long QT syndrome. DESIGN: Left ventricular short axis images at basal and middle levels were recorded on videotape and digitised to reconstruct digitised M mode echocardiograms, from which left ventricular wall thickness curves were obtained. The wall thickening time (ThT) was defined as the period in which the instantaneous wall thickness exceeded 90% of the maximum wall thickness. ThT was measured at three segments in each of the septal and free wall sides of the left ventricle, a total of 12 segments. To examine the mechanical dispersion of the left ventricle, the difference between the maximum and minimum ThT of 12 segments in each subject was obtained. PATIENTS: Eight patients with congenital long QT syndrome (averaged QTc interval (SD) 509 (27) ms1/2) and 10 control subjects (QTc interval 397 (26) ms1/2) were examined. RESULTS: The averaged ThT values of the 12 segments pooled form all subjects were correlated with the QT intervals (r = 0.72, p < 0.005). Thus the averaged ThT in the long QT syndrome patients was longer than in the control subjects (p < 0.005). The segmental variation of ThT in the patients was greater than in the control subjects (p < 0.001). The dispersion of ThT in the patients was therefore larger than in control subjects (p < 0.005). However, the pattern of ThT variation in the patients varied according to the individual subject. CONCLUSIONS: There is not only electrical but also mechanical dispersion in the left ventricle of long QT syndrome patients. Regional assessment of ventricular wall motion may allow quantification of the spatial variation of wall motion abnormality.

Adolescent↗
PubMed1998

Isolation and characterization of kidney-specific ClC-K1 chloride channel gene promoter.

The rat ClC-K1 chloride channel is a kidney-specific member of the ClC chloride channel family found exclusively in the thin ascending limb of Henle's loop in the kidney. To gain insight into the mechanism(s) of kidney-specific expression of ClC-K1, a genomic clone that contains the 5'-flanking region of the rat ClC-K1 gene was isolated. A single transcription start site was located 84 bp upstream of the start codon. The sequence of the proximal 5'-flanking region contained an activator protein (AP)-3 site, a glucocorticoid-responsive element, several AP-2 sites, and several E-boxes, but it lacked a TATA box. To functionally express the promoter, the approximately 2.5-kb pair 5'-flanking region was ligated to a luciferase reporter gene and transfected into inner medullary (IM) cells, a stable ClC-K1-expressing cell line derived from the inner medulla of simian virus 40 transgenic mouse, and ClC-K1-nonexpressing cell lines. Luciferase activity was 7-to 24-fold greater in IM cells than those in nonexpressing cell lines, suggesting that the approximately 2.5-kb fragment contained cis-acting regulatory elements for cell-specific expression of the ClC-K1 gene. Deletion analysis revealed that this cell-specific promoter activity in IM cells was still present in the construct containing 51 bp of the 5'-flanking region but was lost in the -29 construct, clearly demonstrating that the 22 bp from -51 to -30 have a major role in the cell-specific activity of the ClC-K1 promoter. These 22 bp consist of purine-rich sequence (GGGGAGGGG-GAGGGGAG), and gel-retardation analysis demonstrated the existence of a specific protein(s) binding to this element in IM cells. These results suggest that the novel purine-rich element may play a key role in the activity of the ClC-K1 gene promoter.

Animals↗
PubMed1998

Mutations in CLCN5 chloride channel in Japanese patients with low molecular weight proteinuria.

Mutations in the CLCN5 gene have been demonstrated in three disorders of hypercalciuric nephrolithiasis, i.e., Dent's disease, X-linked recessive nephrolithiasis, and X-linked recessive hypophosphatemic rickets. Recently, a number of Japanese children with low molecular weight proteinuria (LMWP) showing symptoms similar to those shown by patients with Dent's disease in British families have also been reported to have mutations in the CLCN5 gene. The present study examines five unrelated Japanese families with LMWP, two of which lacked any signs other than LMWP, and three of which had several signs other than LMWP, i.e., hypercalciuria, aminoaciduria, hypophosphatemia, and rickets. One nonsense (E118X) and one missense (W22G) mutation were found in three patients in the two families having only LMWP. One genomic deletion including exons 5 to 8 in the CLCN5 gene was found in a patient with hypophosphatemic rickets, and a nonsense mutation (R347X) was found in one patient with LMWP and slight hypercalciuria. No mutations of the exons and exon-intron boundaries in the CLCN5 gene were found in one patient with LMWP, aminoaciduria, and hypokalemia. In addition to the predicted loss of chloride channel function in these nonsense and deletion mutations, the loss of function in the missense mutation W22G was confirmed in the Xenopus oocyte expression system. These results clarified four novel mutations in the CLCN5 genes, and additionally suggested that the loss-of-function mutation of the CLCN5 does not necessarily lead to hypercalciuria and nephrocalcinosis in the early stage of the disease, and that LMWP is an early and essential manifestation of disorders of the CLC-5 chloride channel.

Adult↗
PubMed1998

Water purification system by using the biofilter for long-term experiment equipment with aquatic animals for the space station.

We have developed a water purification system that enables long-term experiment with aquatic animals for 90 days or more on the space station. We designed the system that combined a biofilter for ammonia removal (nitrification) with another for nitrate removal (denitrification). The experiment with goldfish was for 90 days with an aquatic animals' examination device. The equipment consists of a fish tank, a filter module, pumps, and an artificial lung for gas exchange. The goldfish were kept in the tank without any water replacement throughout the experiment. When a filter module consists of adsorbents without bacteria, the concentration of the nitrite and ammonia begin to increase so that the goldfish die. On the contrary, neither ammonia nor nitrite accumulated throughout the experiment, and the concentration of T-N also maintained 30 ppm or less when the combined biofilter was used. Moreover, no fish died throughout the period. The water purification system with biofilter enabled us to examine the long-term life support testing. We also report a new denitrification (correction of dentrification) method for the life support system.

Animals↗
PubMed1998

[Computer analysis of polysomnographic data].

Polysomnogram measures electroencephalogram (EEG), electrooculogram (EOG) and chin electromyogram (EMG) to monitor ever-changing brain state during sleep. Polysomnigraphic records are usually scored visually according to Rechtschaffen and Kales' manual. However, scoring more than 1400 pages of record is very time consuming. Therefore, automated scorer has been awaited. However, when a computer makes a hypnogram, it uses a lot of parameters, such as alpha rhythm, sleep spindles, sleep delta waves, rapid eye movements or tonic chin EMG levels. Continuous across night patterns of these parameters provide more important and detailed physiological information than that provided by hypnogram. In this article, the author reviewed analysis methods for EEG, EOG and EMG and discussed the importance of examining continuous across night patterns of sleep parameters.

Humans↗
PubMed1997

Superlattice Formation on Star Polymer Solutions

Polyisoprene (PI) stars (arm number f = 4 approximately 237) were prepared by coupling of PI monoanions with tetrachlorosilane or by cross-linking PI anions with divinylbenzene. The structural ordering of such stars was investigated through small-angle X-ray scattering. PI stars (f > ca. 90) formed a body-centered cubic (bcc) structure near the overlap threshold. This structure changed to a mixed lattice of bcc and face-centered cubic structures with increasing polymer concentration.

Journal Article↗
PubMed1997

Effect of stimulation of nicotinic cholinergic receptors on cortical cerebral blood flow and changes in the effect during aging in anesthetized rats.

The effect of intravenous injection of nicotine on cortical cerebral blood flow (CBF) was examined in urethane anesthetized rats. Nicotine (3-30 microg/kg) increased cortical CBF, independent of mean arterial pressure. This response was attenuated to about a half of the control one after lesioning the nucleus basalis of Meynert (NBM) bilaterally. The response was not significantly influenced after blocking the muscarinic receptors, but was abolished after blocking the nicotinic receptors in the parenchyma of the brain. It is concluded that the nicotine-induced cortical vasodilation was mediated by activation of the nicotinic receptors in the NBM and also in the cortex of the brain. The threshold dose of nicotine for increasing cortical CBF was shifted in aged rats of 23-26 months, and the nicotine-induced increase in cortical CBF was much reduced in aged rats of 32-36 months. Activation of nicotinic receptors in the brain may be of therapeutic value in aged subjects in facilitating the cholinergic neural vasodilative system.

Aging↗