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Biomedical subjects

N Nishimura

Publications and source records attributed to N Nishimura.

At least 37 records · Page 2Linked to original sources
PubMed1991

Transient increase in renal epidermal growth factor content after unilateral nephrectomy in the mouse.

A sensitive enzyme-linked immunosorbent assay for mouse epidermal growth factor was established for measurement of the content of epidermal growth factor in the remaining kidney after uninephrectomy. In 5-week-old male mice, the renal epidermal growth factor content before uninephrectomy was 355 +/- 97 ng/g wet tissue with a 2.1-fold increase on the first day after uninephrectomy, whereafter it gradually decreased. In 15-week-old mature male mice, the renal epidermal growth factor content increased 1.7-fold on the first day after uninephrectomy. Immunohistochemical analysis showed that epidermal growth factor was present in the distal tubular cells and that the staining intensity was increased on the first day after uninephrectomy. During the course of compensatory renal growth, no significant alteration of epidermal growth factor content was observed in plasma or in the submaxillary gland. Our data suggest that the increase in renal epidermal growth factor content after uninephrectomy is due to an increased production of epidermal growth factor in the kidney itself. The significance of this phenomenon is discussed.

Animals↗
PubMed1991

[Bladder replacement with sigmoid colon for bladder cancer].

From 1972 to 1989, 21 patients underwent bladder replacement with sigmoid colon after cystectomy for bladder cancer. A portion of sigmoid colon (about 15 to 20 cm) was isolated and anastomosed to the urethral stump. Then the ureters were implanted in the sigmoid colon via submucosal tunnels. There were 20 men and 1 woman, ranging in age from 24 to 71 years (average 51 years). Preoperative investigations showed that all the cases were free of metastasis. Five years survival rate was 60.7% and there was no operative mortality. There was urethral recurrence in one case and in that case postoperative histopathology revealed carcinoma in situ with tumor. All patients were able to void by themselves without any difficulty. Five patients complained mild incontinence at daytime and all patients had mild incontinence during deep sleep at night, but all of them could maintain their normal daily life like before. The major postoperative complications were: leak at the site of anastomosis (between sigmoid colon and urethra) in 6 cases, hydronephrosis in 2 cases, VUR in 2 cases and bladder stone in 1 case. The patients who underwent bladder replacement with sigmoid colon were well satisfied, because there were no external stoma and the patients could void by themselves. From now, we want to improve our operative method in order to avoid postoperative incontinence.

Adult↗
PubMed1991

[The application of in vivo diffusion weighted magnetic resonance imaging to intracranial disorders].

We have developed a magnetic resonance (MR) spin echo method to obtain diffusion weighted imaging using motion-probing gradient (MPG) pulses in one or three orthogonal directions before and after a 180 degree pulse. Phantom models containing water and acetone, normal volunteers and patients with brain tumors, brain edema and infarction were examined. Experimental models of brain edema including triethyltin intoxication and cold injuries were also examined in Wistar rats. MRI was performed at a 1.0-T clinical machine or a 4.7-T experimental machine using spin echo pulse sequences with or without additional MPGs on one or three orthogonal axes. The one direction method was useful to define diffusion anisotropy of myelinated axonal fibers in white matter. Faster diffusion was detected in the white matter parallel to the direction of MPGs. On the other hand, slower diffusion was detected perpendicular to the direction of MPGs because the myelin sheath restricted water diffusion. The three orthogonal gradients method was useful to demonstrate the difference in the diffusion coefficients in various diseases due to its larger total gradient strength. The clear distinction between the cytotoxic edema, which revealed slower diffusion, and the vasogenic edema, which revealed faster diffusion, was demonstrated in the experimental models using diffusion weighted image. In the clinical cases, faster diffusion was demonstrated in the brain tumor and perifocal vasogenic edema, which was in agreement with the results in the experimental models of rats. Brain tumors such as low grade astrocytoma with microcysts and perifocal vasogenic edema have very wide extracellular space.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[The distribution of solutions in the epidural space].

In 21 patients the distribution within the epidural space of epidurally injected 99mTc-DTPA was assessed. The gamma emissions from the epidural space were measured externally with the patients in supine position by use of a gamma camera. The recordings over the patient's back were stored in digital computer for 60 min. The results were as follows; 1) The spread of the radionuclide was mainly to cephalad direction, and seldom crossed the L5 level to sacral region. 2) The solution injected in the epidural space would distribute to less resistant compartments and the spread depends on the power of injection, negative pressure in the high epidural space and capillary pressure. 3) The elimination half-life of the injected radionuclide was between 1 to 17 min depending on the region in the epidural space. 4) The solution injected in the epidural space may penetrate dura mater at the ink cuff area and local anesthetic agents may affect the spinal nerve roots in the subarachnoid space rather than at the extra-dural space. 5) With continuous infusion technique the diffusion and penetration of the local agent through the dura mater are facilitated and more profound anesthetic effects would be expected. In clinical practice the utilization of the continuous infusion method should be considered along with the bolus injection.

Adult↗
PubMed1990

Transforming growth factor beta-like activity in human hydrocele fluid.

In this study transforming growth factor beta (TGF-beta)-like activity in human hydrocele fluid was investigated. Inhibition of DNA synthesis of adult rat hepatocytes in primary culture and stimulation of colony formation of normal rat kidney (NRK) fibroblasts, clone 49F in soft agar were observed in all acidified hydrocele fluids and these activities were neutralized by the specific antibody raised against human native TGF-beta. In samples obtained from recurrent cases of hydrocele, TGF beta-like activity was observed in its active form (without acidification). These results suggest that human hydrocele fluid contains TGF beta-like activity and that the active form of TGF-beta in recurrent hydrocele fluid may be responsible for the recurrence of the disease even after repeated aspiration.

Animals↗
PubMed1990

High cell density suspension culture of mammalian anchorage independent cells: oxygen transfer by gas sparging and defoaming with a hydrophobic net.

Gas sparging directly into the culture-broth is not done in cell culture, except when the gas flow rate is very small, because much foaming occurs. During screening of defoaming methods, foam was observed to be broken up effectively when it made contact with a net fabricated from hydrophobic materials. Providing a highly efficient oxygen supply to suspension culture was tried using the new defoaming method. In a 5 l reactor equipped with the foam-eliminating net fabricated with polysiloxane, oxygen was transferred at 21 mmole/l.h equivalent to a consumption rate of 1 X 10(8) cells/ml, even at a low oxygen gas flow rate of 0.1 cm/s corresponding to a fourth of the gas flow rate when foam leaked through the net. Perfusion culture of rat ascites hepatoma cell JTC-1 was successfully carried out in the 5 l scale culture system with the net and a hydrophobic membrane for cell filtration. The viable cell concentration reached 2.7 X 10(7) cells/ml after twenty-seven days, in spite of the nutrient-deficient condition of the lower medium exchange rate, that is, a working volume a day, and viability was maintained at more than 90%. In a 1.21 scale culture of mouse-mouse hybridoma cell STK-1, viable cell concentration reached 4 X 10(7) cells/ml. These results showed that oxygen transfer by gas sparging with defoaming was useful for high density suspension culture. A foam-breaking mechanism was proposed.

Animals↗
PubMed1990

The effect of transforming growth factor-beta on the alkaline phosphatase activity in rabbit renal cortical tubular cell cultures.

The effect of various growth regulators including epidermal growth factor and transforming growth factor-beta on the alkaline phosphatase activity of rabbit renal cortical tubular cells has been investigated in a serum-free culture. As a result, it was found that transforming growth factor-beta, known to be a growth inhibitor of renal tubular cells, increased the alkaline phosphatase activity of the tubular cells dose-dependently and that cycloheximide blocked any increase in the activity of this factor. In contrast, epidermal growth factor decreased the alkaline phosphatase activity in the tubular cells.

Alkaline Phosphatase↗
PubMed1990

A study of growth regulators of renal cortical tubular cells in the rabbit liver.

Two growth regulators, a growth stimulator for cultured renal tubular cells and a growth inhibitor, were observed in this study in rabbit liver homogenate after a unilateral nephrectomy. These regulators appeared in the liver on the third day after this nephrectomy, decreased on the seventh day, and disappeared by the fourteenth day. The growth stimulatory activity, termed a tubular cell growth factor (TuCGF), was a heat- and acid stable 15 to 20 KDa protein. The additive effects of TuCGF on the epidermal growth factor (EGF), the insulin-like growth factor-I (IGF-I), and the fibroblast growth factor (FGF) were observed; the results suggest that TuCGF differs from EGF, IGF-I, or FGF. In contrast, the growth inhibitory activity, termed a tubular cell growth inhibitor (TuCGI), was a heat- and acid-labile protein with a molecular weight of about 150 to 200 KDa. This factor potently inhibited the DNA synthesis of tubular cells in the presence of insulin and EGF. These results suggest that TuCGI is not identical with transforming growth factor-beta (TGF-beta). The regulation of these activities by target cell density is also discussed.

Animals↗
PubMed1990

Vitamin K concentrations in the plasma and liver of surgical patients.

Vitamin K deficiency has been reported in patients who were treated with antibiotics and placed on poor diets after surgery. High-performance liquid chromatography (HPLC) was used to study the influence of dietary intake on vitamin K concentrations in surgical patients (n = 22). Plasma phylloquinone decreased rapidly from 1.19 +/- 0.16 to 0.47 +/- 0.12 nmol/L (means +/- SEM, n = 11) on a low-phylloquinone diet and from 1.16 +/- 0.12 to 0.36 +/- 0.07 nmol/L (n = 11) by postoperative fasting. A small amount of phylloquinone and a large amount of menaquinone were found in liver tissue. Phylloquinone concentration was 28.0 +/- 4.3 pmol/g liver (wet weight) on the standard diet (n = 7) whereas it was 6.8 +/- 1.1 pmol/g on the low-phylloquinone diet after 3 d (n = 8). Because phylloquinone is rapidly depleted by fasting, it may be difficult to prevent vitamin K deficiency by dietary phylloquinone alone during long-term fasting after surgery.

Adult↗
PubMed1990

Effects of thiopental, pentobarbital, and ketamine on endothelin-induced constriction of porcine cerebral arteries.

Contractile mechanisms of endothelin, a newly isolated vasoactive substance from endothelium, were evaluated in anterior cerebral arteries (ACA). Furthermore, the effects of thiopental, pentobarbital, ketamine, and diltiazem on the endothelin-induced cerebral vasoconstriction were also studied. Endothelin induced cerebral arterial contractions in concentrations above 3 X 10(-10) M. The median effective concentration (ED50: X10(-9) M) of endothelin was 2.1 +/- 0.7 (n = 6). Endothelin did not elicit contractions in preparations soaked in Ca2(+)-free solution, but addition of 2.5 mM Ca2+ to the baths induced marked contractions. Thiopental and pentobarbital attenuated endothelin-induced contractions at concentrations above 3 X 10(4) M, while ketamine was effective above 10(-3) M. In contrast, diltiazem decreased endothelin-induced vasoconstriction at 10(-6) M. The findings suggest that endothelin may cause contractions of porcine cerebral arteries by influx of Ca2+ through Ca2+ channels. The cerebral vasomotion induced by endothelin, however, does not seem to be influenced by clinical doses of barbiturates and ketamine.

Animals↗
PubMed1990

A clinicopathologic study of tumors and tumor-like lesions of the penis.

A total of 147 specimens from 93 patients with penile lesions were examined at Nagasaki University Hospital during a 27-year period from 1961 to 1987. The most frequent malignant tumor was squamous cell carcinoma (SCC, 33 cases, 35.5%), followed by extramammary Paget's disease, transitional cell carcinoma, and Bowen's disease. The benign tumors and tumor-like lesions included condyloma acuminatum, cyst of the genitoperineal raphe, and lymphangioma. SCC of the penis accounted for less than 0.1% of all specimens and less than 0.62% of malignant tumors in men filed at our hospital. True phimosis accompanied 81.5% of the SCC cases. The 5- and 10-year survival rates for SCC were 77.2% and 71.3%, respectively. Two patients died of penile SCC. It was considered that an absence of both keratohyaline granules in the granular layer and melanin pigment in the basal layer can serve as a useful histologic indicator for diagnosis of well differentiated SCCs that are otherwise difficult to identify.

Adolescent↗
PubMed1990

Isolation of glutamyltaurine from bovine brains and proof of its gamma-linkage by the B/E linked scan SIMS technique.

We isolated a glutamyltaurine from bovine brains and determined its structure as gamma-glutamyltaurine (gamma-Glu-Tau; glutaurine) by use of a new mass spectrometric technique [B/E linked scan sputtered ion mass spectrometry (SIMS)], which we have recently shown to be useful for distinguishing the gamma- from the alpha-isomer of glutamyl-dipeptides. Neither the alpha-isomer of glutamyltaurine nor any aspartyltaurines could be detected in bovine brain.

Animals↗
PubMed1990

Endothelial modulation of norepinephrine-induced constriction of rat aorta at normal and high CO2 tensions.

Endothelial modulation of norepinephrine (NE)-induced constriction of the isolated rat aorta was studied at normal (PCO2, 41 +/- 0 mmHg) and high CO2 tensions (PCO2, 91 +/- 1 mmHg). In preparations with intact endothelium, increased CO2 tension resulted in rightward shift of the NE dose-response curve with attenuation of maximal contraction. This effect of CO2 was not modified by indomethacin. Treatment with hemoglobin or rubbing of the endothelium meant that increased CO2 tension still resulted in rightward shift of the NE dose-response curve but without altering the maximal contractile response. The basal guanosine 3',5'-cyclic monophosphate (cGMP) levels in control and NE-treated aortic preparations were not affected by increasing the CO2 tension. Thus the inhibitory action of CO2 on NE-induced contraction in the presence of endothelium may not be derived from facilitation of endothelium-derived relaxation factor (EDRF)-induced cGMP synthesis. Increasing the CO2 tension attenuated the sustained contraction induced by the addition of NE and Ca2+ (2.5 mM) to intact endothelium preparations previously bathed in Ca2(+)-free solution. Further addition of Ca2+ (total 5.0 mM) did not increase the contraction. These findings suggest that the intrinsic activity of NE is greatly modified by endothelium at a high CO2 tension. Vasodilation during hypercapnia may be induced at least in part by synergistic actions of EDRF and CO2 on smooth muscle cells.

Animals↗
PubMed1990

Localization of metallothionein in the genital organs of the male rat.

We studied the immunohistological localization of metallothionein (MT), a low molecular weight metal binding protein, in male rat genital organs (testis, epididymis, ejaculatory duct, seminal vesicle, coagulating gland, and prostate) by use of the avidin-biotin-peroxidase complex method. MT concentrations in testis, seminal vesicle, and prostate ranged from 15-30 micrograms/g tissue. In testis, seminiferous tubules with mature spermatozoa exhibited weak MT staining, whereas the tubules containing differentiating spermatogenic cells but not containing spermatozoa showed strong MT staining. No MT immunostaining was observed in Leydig cells. In growing rat testes, the pattern of MT immunostaining was found to change with development: MT was found in supporting cells only on Day 7, spermatogonia adjacent to basement membrane on Day 14, and spermatocytes localized in the central part of the tubules on Day 21. Strong MT immunostaining in the basal cells was a common feature in other genital tissues, except the ductus efferentes. In prostate, the strongest MT staining was found in the lateral lobe, and MT was localized in apocrine secretions in the dorsal lobe. The present results suggest a close association of MT with cell proliferation and differentiation, as well as possible involvement of MT in supply or storage of zinc ions.

Animals↗
PubMed1990

Simultaneous determination of the free and total carbamazepine concentrations in human plasma by high-performance frontal analysis using an internal-surface reversed-phase silica support.

High-performance frontal analysis (HPFA) was applied to simultaneous determinations of the free and total carbamazepine (CBZ) concentrations in human plasma. When 1.5ml of human plasma containing CBZ at a clinical therapeutic level (free fraction, about 30%) was directly injected into an internal-surface reversed-phase silica column, the CBZ was separated from the plasma blank and was eluted as a zonal peak with a plateau height corresponding to the free CBZ concentration in protein binding equilibrium. Slow and continuous introduction of the plasma sample and the use of titanium filters permitted us to inject the sample repeatedly while avoiding a rapid increase in column pressure. The free and total CBZ concentrations were determined simultaneously from the peak height at the plateau region and the area of the CBZ peak, respectively. The within-run and day-to-day reproducibilities were satisfactory (C.V. less than or equal to 1.63%, n = 5).

Carbamazepine↗
PubMed1990

[Effect of anti-ulcer drugs and PGE2 on the proliferation of rat gastric cultured cells].

The effects of anti-ulcer drugs and PGE2 on the proliferation of rat gastric cultured cells were investigated. To study the cell proliferation, the rate of incorporation of 3H-thymidine into the cultured cells was measured. ULTROSER G, corresponding to fetal bovine serum, was found to dose-dependently increase the incorporation of 3H-thymidine into the cultured cells at a dose range of 1-4%. The incorporation of 3H-thymidine was highest at 36 hr after the inoculation of cells. Therefore, the effect of the drugs on the proliferation was performed under the condition of 2% ULTROSER G and evaluated at 36 hr. Aldioxa, cetraxate HCl, cimetidine (10(-7)-10(-5) M) and PGE2 (10(-8)-10(-6) M) had no effect on the cell proliferation, while indomethacin (0.35-1.41 x 10(-3) M) inhibited the proliferation in a dose-dependent manner. Aldioxa, cetraxate HCl (10(-5) M) and PGE2 (10(-6), 10(-8) M) antagonized the inhibitory effect by indomethacin at a concentration of 0.5 x 10(-3) M, but cimetidine (10(-7)-10(-5) M) did not. From the above results, it was concluded that this method was useful for investigating the effect of drugs on the proliferation of gastric cultured cells.

Animals↗
PubMed1990

[Effect of feeding on recording characteristics of electrogastrography (EGG) in normal subjects].

Cutaneous recording of electrogastrography reflects gastric mechanical activity. Epigastric leads are superior in recording characteristics than meso-gastric leads, in fasting state, 3.0 cpm waves dominate EGG recording in fasting state. In this study, we analyzed the EGG recording characteristic after feeding in 10 normal subjects. Though the physical changes of gastric shape and volume after feeding, EGG recording was dominated by 3.0 cpm waves. Epigastric leads are still superior in recording characteristics, amplitude of EGG waves and read-abilities, than meso-gastric leads, after feeding. Amplitude of EGG waves increased after feeding when compared to fasting state, suggesting increased mechanical activity of the stomach. We conclude that epigastric leads are suitable in recording of EGG in fasting and in fed state in normal subjects. This position could be most standard recording leads for EGG in clinical settings.

Action Potentials↗