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Biomedical subjects

Y Noguchi

Publications and source records attributed to Y Noguchi.

At least 271 records · Page 15Linked to original sources
PubMed1994

[Two cases of coronary artery bypass grafting using great saphenous vein grafts in reversed Y-shaped for the atherosclerotic ascending aorta].

Coronary artery bypass grafting (CABG) was performed using saphenous vein grafts anastomosed in reversed Y-shaped in two patients because of the atherosclerotic ascending aorta. Postoperative course was uneventful, however, the common part of reversed Y-shaped grafts was occluded in both patients within two years after operations. The arms of reversed Y-shaped grafts were patent, and played a role of major collateral between LAD and RCA. They were treated successfully with reoperation in one patient and PTCA in another.

Aged↗
PubMed1994

Growth plate matrix vesicle biogenesis. The role of intracellular calcium.

Isolated bovine growth plate chondrocytes suspended in a synthetic cartilage buffer containing 10(-7) to 10(-3) M concentrations of calcium were treated with 1 microM ionomycin to induce changes in intracellular ionized calcium as measured by Fura-2 fluorescence. An increase in intracellular calcium of 10(-6) to 10(-4) M calcium resulted in the secretion of vesicles that contain alkaline phosphatase. An increase in intracellular calcium above 10(-4) M resulted in nonspecific cell fragmentation because of cell damage. Electron microscopy of the secreted vesicles demonstrated that their structure resembled matrix vesicles. Isolated cells treated with ionomycin (synthetic cartilage buffer with 10(-6) M calcium) demonstrated intact cell membranes, normal intracellular architecture, and numerous plasma membrane processes undergoing vesiculation. The plasma membrane of these isolated cells and the isolated vesicles demonstrated a positive stain for alkaline phosphatase. Fresh growth plate tissue demonstrated plasma membrane staining for alkaline phosphatase at the lower proliferative and upper hypertrophic cell zone, and an increasing number of alkaline phosphatase stained matrix vesicles in the matrix of the lower hypertrophic cell zone. The data indicate that an increase in intracellular calcium in the lower proliferative and hypertrophic cell zones of the growth plate induces the secretion of plasma membrane derived matrix vesicles.

Alkaline Phosphatase↗
PubMed1993

Role of endothelin ETB receptors in bronchoconstrictor and vasoconstrictor responses in guinea-pigs.

In anesthetized and ventilated guinea-pigs, intravenous injections of endothelin (ET)-1 (0.5 nmol/kg), ET-3 (0.5 nmol/kg), and [Ala1,3,11,15]ET-1 (20 nmol/kg), an ETB-selective receptor agonist, induced bronchoconstrictor and transient vasoconstrictor responses. Only the ET-1-induced transient vasoconstriction was followed by a secondary sustained pressor response. The ETA-selective receptor antagonist, BQ-123 (1 mg/kg i.v.), attenuated only the sustained pressor response. These results indicate that the bronchoconstrictor and transient vasoconstrictor responses to endothelins in guinea-pigs are mediated by ETB receptors, whilst the sustained pressor response is mediated by ETA receptors. The thromboxane A2 receptor antagonist, L-670,596 (0.5 mg/kg, i.v.) and a high dose of BQ-123 (30 mg/kg i.v.) abolished the bronchoconstriction only without affecting the transient pressor response to endothelin isopeptides. These results suggest that the ETB-mediated bronchoconstriction depends on thromboxane A2 formation. The different sensitivity of these ETB-mediated transient responses to BQ-123 suggests the possible existence of distinct ETB receptor subtypes.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1993

Beam-shaping optics for a slit-scan flow cytometer.

Two sets of beam-shaping optical systems for slit-scan flow cytometry were made for 360 nm and 488 nm wavelength argon-ion lasers. A thin, ribbonlike laser beam was formed by compressing the zero-order component of Fraunhofer diffraction patterns caused by a slit vertically long and horizontally narrow by means of an objective with a numerical aperture of 0.5. The objectives were designed to include a jet stream that performed as a cylindrical lens. The characteristic values of the optical systems and lens alignments of the systems are described in this work. The beam size at focus was 0.95 micron in thinness and 85.0 microns in width on design values. The actual beam thinness for the UV laser was estimated to be 1.3 microns, based on shapes of pulses generated when fluorescence microspheres of diameter 1.0 microns passed across the beam. The usefulness of the optical systems was also proved by its ability to measure HeLa chromosomes.

Analog-Digital Conversion↗
PubMed1993

Tumor-induced alterations in hepatic malic enzyme and carnitine palmitoyltransferase activity.

To better understand the role of the liver in the hypertriglyceridemia observed in a tumor-bearing state, we have examined tumor-induced alterations in hepatic lipogenesis and fatty acid oxidation. The effects of differing tumor burden as well as tumor excision on the activity and mRNA levels of malic enzyme and carnitine palmitoyltransferase were studied in Fisher 344 rats bearing a methylcholanthrene-induced sarcoma. Serum triacylglycerols and plasma nonesterified fatty acids (NEFA) levels were both elevated with increasing tumor burden (P < 0.05 vs control). The elevation disappeared with tumor removal. Malic enzyme activity of tumor bearers, compared with control rats, declined with an increase in tumor burden. These two variables were negatively correlated (r = -0.90, P < 0.01). The changes in activity were accompanied by positively correlated changes in mRNA levels (r = 0.73, P < 0.01). Carnitine palmitoyltransferase activity was not altered, even in the presence of a large tumor burden. Hepatic lipogenesis, reflected by malic enzyme activity, was tumor-dependent and was significantly reduced during the period of circulating hypertriglyceridemia. Fatty acid oxidation, reflected by carnitine palmitoyltransferase activity, was not enhanced in spite of an ample supply of NEFAs to the liver from the peripheral tissues. The data suggest that neither hepatic lipogenesis nor fatty acid oxidation contribute to hypertriglyceridemia in the tumor-bearing state.

Animals↗
PubMed1993

Long-term total parenteral nutrition and osteoporosis: report of a case.

A patient who had been supported with total parenteral nutrition (TPN) for over 8 years is herein presented, with emphasis on the changes observed in calcium metabolism. The patient was a 31-year-old female, who had undergone a subtotal jejunal and ileal resection for superior mesenteric artery occlusion. TPN was started soon after the surgery. She had been on TPN support for 105 months. Back pain developed at 97 months after the initiation of TPN. During her course, the serum calcium levels were judged to be within the normal ranges, while the 1 alpha, 25(OH)2Vit.D declined. Intermittent hypercalciuria was occasionally observed. Both the serum level of calcium and urinary calcium loss correlated closely to the amount of calcium infused, but they were not influenced by the amount of vitamin D (ergocalciferol) received. The serum level of parathormone and calcitonin were also within the normal ranges. The patient's vertebral bone, which was obtained at autopsy, revealed histopathological changes characteristic of osteoporosis. Based on the above, we conclude that a careful monitoring of the amount of calcium infused is called for to prevent bone disease in patients on long-term parenteral nutrition.

Adult↗
PubMed1993

Long-term effect of radical gastrectomy on nutrition and immunity.

The long-term effects of gastrectomy on the nutritional and immunologic status were prospectively studied in 79 gastric cancer patients who underwent curative gastrectomy and were followed by us after operation for an average of 5 years and 3 months. The percent of actual weight to pre-illness normal weight was lower than 95% in 80% of all study patients. Retinol binding protein, prealbumin, and albumin were lower than normal in 17%, 26%, and 26% of the patients, respectively. The mean values of the percent normal weight, retinol binding protein, and prealbumin were significantly lower in the totally gastrectomized patients than in the subtotally gastrectomized ones (P < 0.01). The procedures of reconstruction did not affect the nutritional status except for the prealbumin level which was significantly decreased in Roux-en-Y cases than in interposed cases of totally gastrectomized patients. Cell-mediated immunological alterations after gastrectomy were observed in 31%, 37%, and 71% of all patients for OKT3 subpopulation, OKT4/OKT8 ratio, and blastogenesis by phytohemagglutinin, respectively. A multivariate analysis revealed that the long-term immunity of the gastrectomized patients after operation was not affected by the levels of albumin and rapid turnover proteins but by the splenectomy and weight loss they underwent.

Adult↗
PubMed1993

The effects of a biological response modifier, OK-432, on tumor-induced alterations in the host metabolism.

The effects of multicytokine inducer, OK-432, on tumor-induced metabolic alterations were studied by assessing three key regulatory enzymes of gluconeogenesis, de novo fatty acid synthesis and the triglyceride clearance pathways. Two Klinish Einheit (KE) of OK-432 was subcutaneously injected on alternate days, for 10 days, into Fischer 344 rats with or without methylcholanthrene-induced sarcoma. At the time of sacrifice, the tumors accounted for approximately 23% of their total body weight. The injections of OK-432 did not affect the amount of food intake in either the tumor bearers or the controls. The tissue lipoprotein lipase activities in the epididymal fat pads of the tumor bearers were significantly decreased compared with the controls (P < 0.01). Phosphoenolpyruvate carboxykinase activity in the liver was significantly increased (P < 0.01), while malic enzyme activity tended to be decreased in the tumor bearers compared with the controls. However, there were no significant differences in those activities depending on the OK-432 injections, even though OK-432 induced tumor necrosis factor (TNF) and increased cytotoxic activities in the mesenteric lymph nodes as well as in the spleen. Thus, although the role of monokines in inducing cancer cachexia is not yet clearly understood, OK-432 was not able to revert the tumor-induced metabolic alterations which lead to tissue wasting and cancer cachexia.

Animals↗
PubMed1993

Development of preimplantation guinea-pig embryos in serum-free media.

This study was undertaken to determine how far preimplantation guinea-pig embryos can develop normally in vitro with serum-free media generally used for mouse (Whitten's medium, WM) and rabbit (Kane's medium, KM) embryos. Preimplantation guinea-pig embryos were recovered from naturally mated females at each day of pregnancy between Day 1 and Day 6, and were cultured in vitro with either WM or KM at 37 degrees C in 5% CO2 in air. One-cell (Day-1) and 2-cell (early Day 2) embryos cultured in WM developed to the 4-cell and morulae stages respectively, whereas the corresponding embryos cultured in KM arrested development at the 2-cell and 8-cell stages respectively. In contrast, 4-cell (late Day 2 and Day 3) embryos proceeded to the blastocyst stage in KM, but not in WM. Eight-cell embryos (Day 4) and morulae (Day 5) developed to blastocysts in either medium. However, hatching of the blastocysts and trophoblast outgrowth on the culture dish were supported only by KM even when collected at the blastocyst stage. The present study suggests that, in guinea-pig embryos, a distinct change in nutritional requirements occurs around the time of the second cell division and that, unlike in the mouse, trophoblast outgrowth in the guinea-pig requires no supplementation of serum or extracellular matrices.

Animals↗
PubMed1993

Auditory event-related potentials and reaction time in children: evaluation of cognitive development.

The authors studied age-related correlations of auditory event-related potentials (ERPs) using the conventional 'oddball' paradigm and reaction time in 175 normal subjects, aged between four and 21 years. From four years, the latencies of N100, N200 and P300 in ERP progressively shortened until about 16 to 17 years, after which they reached adult level, but with a slight tendency to prolongation towards 20 years; there was no trend for amplitude changes. The reaction time was more rapid than that of P300 latency. These findings indicate that the cognitive function of children improves rapidly until 16 to 17 years. A reduced difference between P300 latency and reaction time with age implies additional progress in motor skill. Combining P300 latency and reaction-time studies may provide more detailed information for the evaluation of the development of cognitive function and motor skill.

Adolescent↗
PubMed1993

Dynamic MR imaging in the head and neck.

PURPOSE: To determine the utility of dynamic magnetic resonance (MR) imaging in evaluation of head and neck lesions. MATERIALS AND METHODS: Dynamic MR imaging was performed in 79 head and neck lesions. Five types of time versus signal intensity curves were obtained: type A, curve peaks 0-30 seconds after administration of contrast material; type B, curve peaks at 30-60 seconds; type C, curve peaks at 60-210 seconds; type D, gradual upward slope; and type E, flat. RESULTS: Use of dynamic imaging did not improve the sensitivity of nondynamic imaging for malignancy. Although malignancies had type B, C, or D curves, 39 (68%) of 57 benign lesions had the same patterns. Lesions with type A or E curves and lesions with type D curves and with marked hyperintensity on T2-weighted images were all benign. CONCLUSION: Although use of dynamic MR imaging contributes little in predicting malignancy in head and neck lesions, it can limit the differential diagnosis and has potential in predicting vascularity and recurrence.

Contrast Media↗
PubMed1993

Hereditary hydronephrosis in C57L/MsNrs mice.

Inbred C57L/MsNrs mice (66 males and 72 females) maintained at the National Institute of Health, Japan, were examined grossly for hydronephrosis. Unlike the hydronephrotic strains of mice reported so far, C57L mice showed no sex-related difference in the incidence (62% in males and 75% in females; P > 0.05) and severity of hydronephrosis. The right kidney was more severely affected than the left kidney in both sexes. Age appeared to have no influence on the incidence.

Animals↗
PubMed1993

[Clinical evaluation of pressure-flow test to male patients with micturition disturbance].

We examined pressure-flow test results in 28 male patients with micturition disturbance in whom it is difficult to determine whether bladder outlet obstruction or impaired detrusor contractility is the cause. One reason that some patients do not improve after prostatectomy is that detrusor contractility was not estimated before preoperatively. The degree of infravesical obstruction and of detrusor function were assessed by the method of Griffiths' diagram (maximum flow rate versus corresponding detrusor pressure). Three patients showed infravesical obstruction, 11 equivocal obstruction, and 14 no obstruction. No patients showed strong detrusor function, 14 normal function, and 14 weak function. Eleven patients underwent TU-procedure. Two patients with normal detrusor function and infravesical obstruction showed good postoperative improvement of uroflowmetry results, but 4 patients with weak detrusor function and no infravesical obstruction showed no improvement. Preoperative assessment of the degree of infravesical obstruction and of detrusor function by pressure-flow testing is therefore considered useful. We emphasize that preoperative evaluation of detrusor function is an important aspect of treatment of male micturition disturbance.

Adult↗
PubMed1993

[Antigen-induced dynamic alterations of endothelin receptors--guinea pig lung tissues].

Endothelins (ETs) are a family of peptides with potent constrictive activity in vascular and treacheal smooth muscle. The lung tissues are abundant in these peptides and their receptors; the peptides are produced by endothelial cells and airway epithelial cells, while its receptor is mainly located on smooth muscle. Therefore, it has been proposed that endothelins act in a paracrine fashion on nearby smooth muscle, thus regulating its tone. However, little is known about its physiological and pathological roles in pulmonary functions. We hypothesized that ET plays an important role in bronchoconstriction elicited by antigen challenge. In order to test this hypothesis, we investigated tracheal contractile activities and ET-receptors by employing an animal model in guinea pigs. Here, we report that guinea pigs who were sensitized followed by multiple challenges with the antigens had alterations of ET receptor(s) with respect to number and affinity.

Animals↗