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Biomedical subjects

S Tsuchida

Publications and source records attributed to S Tsuchida.

At least 37 records · Page 2Linked to original sources
PubMed1996

Stimulatory and inhibitory effects of sodium nitroprusside on soluble guanylate cyclase.

We investigated, using rat brain cortex supernatant as a source of guanylate cyclase (GC), whether sodium nitroprusside (SNP) can not only activate but also inhibit GC. SNP (I and 10 microM) activated the rat brain GC; however, at higher concentrations GC activation was reduced, resulting in a bell-shaped concentration-activation curve. Preincubation of GC with 10 microM SNP attenuated GC activation by SNP, S-nitroso-N-acetylpenicillamine (SNAP) or 3-morpholinosydnonimine-N-ethyl-carbamine (SIN). Such inhibitory effects of SNP were partially supressed by a nitric oxide (NO) scavenger oxyhemoglobin. The preincubation of GC with K4Fe(CN)6 (a carrier molecule for SNP but devoid of NO) had no inhibitory effects on GC activation. These results indicate that SNP, probably through NO, has dual effects on GC activity, stimulation and inhibition.

Animals↗
PubMed1996

Cancer-associated retinopathy in a patient with endometrial cancer.

PURPOSE: We studied a case of unusual retinopathy in a 60-year-old woman. METHOD: The patient developed bilateral retinopathy with iridocyclitis and vitreitis. Corticosteroid therapy could not prevent deterioration of visual acuity and field. The electroretinogram became nonrecordable, and fluorescein angiogram exhibited retinal pigment epithelium window defects, fluorescein stainings to the vascular walls, and narrowed arterioles. RESULTS: The patient underwent hysterectomy and lymphadenectomy for endometrial cancer in the corporis uteri. She was found to possess antibodies against retinal 34-kd protein, leading to a diagnosis of cancer-associated retinopathy. CONCLUSION: Cancer-associated retinopathy may occur in patients with endometrial cancer of the corporis uteri.

Antibodies, Neoplasm↗
PubMed1996

Early and late postoperative hearing preservation in patients with acoustic neuromas.

OBJECTIVE: To examine the incidence of postoperative hearing preservation and the factors that influence early and late postoperative hearing in patients with acoustic neuromas. METHODS: We reviewed the results of surgery and follow-up in 73 consecutive patients. RESULTS: Of 73 patients, 51 demonstrated preoperative hearing levels equal to or better than Class 3, according to the classification system of Gardner and Robertson (8). After surgery, 21 (41.2%) of the 51 patients retained Class 1, 2, or 3 hearing. Hearing was more likely to be preserved after surgery if the tumor was small and if the preoperative hearing was good. The early postoperative hearing grade declined in 7 (33.3%) of the 21 patients, compared with the preoperative hearing level. The long-term follow-up of 17 patients in whom measurable hearing was retained after surgery indicated that 3 (17.6%) experienced delayed worsening of hearing, without evidence of tumor recurrence. The extent of hearing loss in patients with successful hearing preservation was not correlated with tumor size, preoperative hearing, patient age, or the shape of the cochlear nerve on the tumor surface. Hearing at long-term follow-up was significantly better in patients with excellent preoperative hearing. CONCLUSION: Postoperative long-term preservation of hearing is more likely if surgery is performed while the tumor is still small and hearing is still excellent. Under these circumstances, it is more likely that the early and late hearing loss will be compensated.

Adult↗
PubMed1996

Lentinan enhances sensitivity of mouse colon 26 tumor to cis-diamminedichloroplatinum (II) and decreases glutathione transferase expression.

We investigated the influence of a combination of lentinan, a biological response modifier, and cis-diamminedichloroplatinum(II) (CDDP) on the growth and glutathione S-transferase (GST) content of colon 26 tumor to examine whether lentinan represses GST expression and enhances the therapeutic effects of CDDP. Female CDF1 mice inoculated subcutaneously with transplantable colon 26 adenocarcinoma cells (1 X 10(6)/mouse) received intraperitoneal administrations of lentinan, CDDP, or the two drugs in combination, on days 10, 14, 17 and 21 after the inoculation. On day 24, tumor weights (estimated from their length and width) were significantly lower in the CDDP+ lentinan group (2.7+/-1.3 g) than in the CDDP alone group (4.3+/-0.7 g, P<0.05), both values being less than in the nontreated control group (7.2+/-1.5 g). The major GST form of colon 26 tumor was identified as GST-II, the Pi class form, and a minor form as GST-III belonging to the Mu class. Both GST-II and GST-III values on day 24 were significantly decreased in the lentinan alone (0.90+/-0.29 and 0.26 +/-0.11 microg/mg protein, respectively) and lentinan + CDDP groups (0.98+/-0.22 and 0.29+/-0.07 microg/mg protein), as compared with the control levels (1.39+/-0.20 and 0.52+/-0.11 microg/mg protein). However, these values were not different between the CDDP alone and lentinan + CDDP groups. Neither tissue interleukin (IL)-6, glutathione nor platinum values were different between the two groups. IL-6 values were elevated in about half of the samples treated with lentinan or CDDP and exhibited a modest inverse correlation with GST-II levels (r= -0.46). A GST inhibitor, ethacrynic acid, enhanced the sensitivity of cultured colon 26 cells to CDDP, suggesting the possible involvement of GST in modulating the cytotoxicity of CDDP to this cell line. These results indicated that lentinan administration decreases tissue GST-II and GST-III contents and enhances the sensitivity of colon 26 tumor to CDDP.

Adenocarcinoma↗
PubMed1996

Urinary uric acid excretion in term and premature infants.

OBJECTIVE: To clarify postnatal changes in urinary uric acid (UA) excretion in normal term infants and to examine the effects of prematurity or illness on the UA excretion. METHODOLOGY: Measurements of urinary UA were performed in term and premature infants at the ages of 1 and 7 days and at 1 and 4 months, as well as 7 months in term infants. RESULTS: Urinary UA levels were lowest on day 7 in term infants. The levels were highest on day 1 in premature infants and remained significantly higher compared to term babies during the first month of life. Respiratory failure requiring ventilation and oxygen supply resulted in further significant elevation of urinary UA in premature infants. CONCLUSIONS: With the reference values obtained in the study reported here, urinary UA can now be used for the diagnosis and monitoring of inherited disorders of purine metabolism and for the assessment of oxygen radical insult to sick infants.

Age Factors↗
PubMed1996

Ultrasonography for the detection of ureteric reflux in infants with urinary infection.

Several less harmful methods than voiding cysto-urethrography for detecting significant ureteric reflux have been proposed. The present prospective study investigated whether ultrasonography was effective in identifying ureteric reflux in infants with their first febrile urinary infection. The subjects were 27 infants (24 boys and 3 girls) aged from 0 to 8 months. The urinary tract was scanned when the bladder was full, and before and during induced voiding. Infants with abnormal ultrasound findings underwent voiding cysto-urethrography. The other infants were followed and those who had a recurrence of urinary infection underwent voiding cystography. Ten children underwent cysto-urethrography, with eight refluxing ureters identified in six boys. Ultrasound revealed transient dilatation of the renal pelvis on voiding in five kidneys, transient dilatation of distal ureters in 12 and hydro-ureteronephrosis in two. Each of the five kidneys with pelvic dilatation on voiding was associated with ureteric reflux grades III or IV. Of the 17 children who did not undergo cysto-urethrography, only one had recurrence of urinary infection and was diagnosed with ureteric reflux. This girl was one of the three babies who were not scanned during voiding. More than half of the infants with febrile urinary infection were excluded from invasive examination without having recurrence of urinary infection. Thus, ultrasound scanning during voiding was effective for screening infants with their first urinary infection to detect significant ureteric reflux.

Diagnosis, Differential↗
PubMed1996

Renal functional measurements in young rats with chronic inhibition of nitric oxide synthase.

The purpose of the present study was to examine renal functional changes caused by chronic blockade of nitric oxide (NO) synthesis in young rats. Two types of NO synthase inhibitor were used: NG-nitro-L-arginine methyl ester (L-NAME) as a non-selective inhibitor and aminoguanidine (AG) as a selective inhibitor of the inducible isoform. Oral administration of L-NAME (20-80 mg/dL of drinking water), not AG (400 mg/dL), for 4 weeks induced systemic hypertension in the treated rats. Both inhibitors caused a significant reduction in urinary excretion of NO2-/NO3-. Rats treated with L-NAME developed proteinuria and tubular enzymuria (high excretion of N-acetyl-beta-D-glucosaminidase) in a dose-dependent fashion, with normal serum levels of creatinine, albumin and cholesterol. Chronic AG administration did not alter the urinary levels of protein and N-acetyl-beta-D-glucosaminidase or serum laboratory values. Overall, these observations highlight the importance of the continuous generation of NO by the constitutive isoform in the control of vascular tone and the maintenance of renal glomerular and tubular function. Oral administration of L-NAME may serve as a model of chronic NO-deficient hypertension with renal injury in young rats.

Animals↗
PubMed1996

Epidemiology of infant Kawasaki disease with a report of the youngest neonatal case ever reported in Japan.

Our objectives were to describe epidemiological pictures of infant Kawasaki disease (KD) and to report the youngest patient ever reported in Japan. A Japanese database of 105755 KD patients reported in the 25 year period since 1970 was analyzed. Of all the cases registered, there were only six cases aged 30 days or younger and 1768 cases (1.67%) aged 90 days or younger. We reported a typical case of KD (female, the onset at 20 days old) who was the youngest patient ever reported in Japan. The epidemiology of KD in early infants does not contradict the infection theory of the etiology; the rare incidence in the neonatal period can be explained by the protective effects of the passive immunity transferred from the mother and by exposure to the unknown infectious agents.

Age of Onset↗
PubMed1996

Effect of nitric oxide synthase inhibitors on bone metabolism in growing rats.

We examined the effects of chronic nitric oxide (NO) blockade on bone mineral status in growing rats. Oral administration of NG-nitro-L-arginine methyl ester (L-NAME) for 4 wk caused hypertension and a significant reduction in urinary NO2- and NO3- excretion. Four-week oral aminoguanidine (AG, 400 mg/dl of drinking water) did not alter blood pressure but caused a significant decrease in urinary NO2- and NO3-. Rats treated with L-NAME at doses of 20 and 50 mg/dl had normal bone mineral mass in the lumbar spine, but the highest dose (80 mg/dl) caused a slight decrease in bone mass. Chronic AG induced a significant spine osteopenia. This effect of AG was abolished by the simultaneous administration of L-arginine (2.0 g/dl). AG-induced osteopenia was associated with a significant increase in urine excretion of collagen cross-links with normal serum osteocalcin. These findings indicate that chronic AG administration can cause an imbalance between bone resorption and formation, resulting in a decrease in bone mass in growing rats, and suggest that NO produced by inducible NO synthase plays an important role in basal osteoclast bone degradation activity in vivo.

Absorptiometry, Photon↗
PubMed1996

Ultrasonographic findings of acute tubulointerstitial nephritis.

Three children were diagnosed as having acute renal failure due to acute tubulointerstitial nephritis (TIN) associated with Yersinia pseudotuberculosis infection. The kidneys were observed ultrasonically during the disease course. The subjects presented with remittent fever, vomiting or diarrhea, and nonoliguric acute renal failure with sterile pyuria and tubular reabsorptive dysfunction. Ultrasound examination delineated marked enlargement of the kidneys with diffuse hyperechogenicity in the cortex, suggesting the diagnosis of TIN. The renal swelling was marked in the descending order of width, depth and length, respectively, and reached more than 200% in volume in 1 of the children who was examined at the culminating stage of acute renal failure. The enlarged kidneys reduced in size in parallel as the elevated serum creatinine levels decreased. However, the enlarged kidneys did not seem to return to their original sizes: the kidney size in 1 of the children remained well above the upper allowance limit of the body-height-related normals and in the other 2 they were only a little smaller than the upper limits. These ultrasound findings should help with the diagnosis and follow-up of the disease.

Acute Disease↗
PubMed1996

A study of anterior pituitary hormones secretion in patients with glioma receiving interferon-beta treatment.

Human interferon beta (IFN-beta) has been used for the treatment of patients with benign and malignant astrocytomas. The effect of IFN-beta on pituitary function, however, has not been precisely evaluated before. In this study the serum levels of various anterior pituitary hormones including GH, PRL, ACTH, and TSH were measured to determine the effects of IFN-beta on pituitary endocrine function in 19 consecutive glioma patients receiving IFN-beta. Daily doses of 3 x 10(6) U of IFN-beta were administered as a 30-min intravenous drip infusion beginning at 0800 h every morning during the first week and then 4 times a week for additional 6 weeks. Blood samples were taken on the day prior to administration as controls (0900 h and 1500 h), and on the first day of administration (0900 h and 1500 h) and after 7 days of administration (0900 h) in order to determine the acute and chronic or integrated effects of IFN-beta on the above pituitary hormones. No significant change in serum concentrations of any of the pituitary hormones examined was observed, suggesting that human natural IFN-beta used for the treatment of gliomas has no significant effect on the secretion of these hormones from the pituitary in these patients.

Adolescent↗
PubMed1996

Induction of apoptosis but not G1 arrest by expression of the wild-type p53 gene in small cell lung carcinoma.

Multiple genetic alterations, including inactivation of the p53 and RB genes and loss of heterozygosity on chromosome 3p, occur commonly in small cell lung carcinoma (SCLC). To assess the biological significance of p53 inactivation in the development of SCLC, tetracycline (Tc)-inducible p53 expression plasmids were introduced into a SCLC cell line, N417, in which the p53 gene as well as the RB gene was inactivated. In the absence (induced) of Tc, cells transfected with the wild-type p53 gene formed colonies in 29-58% of those with a mutant p53 gene. However, wild-type p53 genes were expressed in 0 of 43 transfectants, whereas mutant p53 genes were expressed in 75% (36/48) of the transfectants, suggesting that the growth of SCLC cells was suppressed by the expression of the wild-type p53 gene. Thus, wild-type p53-inducible clones were further established by transfection in the presence (repressed) of Tc. The in vitro growth was significantly suppressed by the induction of wild-type p53 expression, and apoptosis but not G1 arrest was observed within 24 h of p53 induction. These results strongly suggest that the restoration of the p53 function is sufficient to suppress the growth of SCLC cells in which other genetic alterations remain uncorrected, and that growth suppression by p53 is due to induction of apoptosis but not due to induction of G1 arrest through the RB pathway.

Apoptosis↗
PubMed1995

Hyporesponsiveness to nitrovasodilators in rat aorta incubated with endotoxin and L-arginine.

We studied the effect of L-arginine on relaxation responses to sodium nitroprusside or SIN-1 (3-morpholinosydonimine-N-ethyl-carbamine) in the rat thoracic aorta incubated with endotoxin. Sodium nitroprusside or SIN-1 produced a reproducible relaxation in the aorta incubated for 12 h with endotoxin. However, the response to both nitrovasodilators was remarkably attenuated when the aorta was preincubated for 12 h with endotoxin and L-arginine. D-Arginine could not substitute for L-arginine. The attenuated response to sodium nitroprusside or SIN-1 was partially restored by the inhibition of nitric oxide (NO) production with N omega-nitro-L-arginine. Cycloheximide prevented the inhibitory effect of preincubation with L-arginine. These results suggest that the prolonged exposure to muscle-derived NO induces hyporesponsiveness to nitrovasodilators.

Animals↗
PubMed1995

Acute tubulointerstitial nephritis in association with Yersinia pseudotuberculosis infection.

A 4-year-old girl was diagnosed as having acute renal failure due to tubulointerstitial nephritis. The girl presented with remittent fever, vomiting and non-oliguric acute renal failure with sterile pyuria and tubular reabsorptive dysfunction. Ultrasound examination revealed that the kidneys were markedly enlarged with diffuse hyperechogenicity in the cortex when the abnormal renal function was present and were restored in size and echogenicity when the renal function normalised. A diagnosis of Yersinia pseudotuberculosis infection was based on a rise in haemagglutination titres against the organism.

Acute Disease↗
PubMed1995

Ultrasonographic evaluation of bladder volume in young children.

We investigated by ultrasonography the bladders of 30 young children (26 boys, 4 girls) without established bladder control immediately before voiding cystourethrography. The anterior/posterior (D), superior/inferior (H) and transverse dimension (W) of the bladder were determined. The small children had a significantly greater H value compared with D and W than older children in our previous study in 1993. The regression equation for D x H x W and actual bladder volume in 30 infants was calculated as y = 0.49 x + 3 (Eq. 1). When bladder volume of the 30 infants was estimated from D x H x W, the mean percentage error was much lower with Eq. 1 than with Eq. 2 (y = 0.68 x + 4), which had been determined for older children (mean +/- SD 16.8% +/- 10.7% vs. 44.7% +/- 26.2%) (P < 0.01). Thus, infants have a different bladder shape than older children and their bladder volume should be estimated using a specific formula designed for them.

Child, Preschool↗
PubMed1995

Lighted mirror for microneurosurgery.

We describe a newly developed, lighted mirror that provides enough luminous intensity to obtain a clear image in deep operative fields under high magnification. Through the initial neurosurgical procedures in which it was tested, the mirror proved particularly useful for inspecting the ventral aspect of the fifth nerve in a microvascular decompression for trigeminal neuralgia, and for observing the fundus of the internal auditory meatus after removal of an acoustic neuroma to ensure no residual tumor.

Humans↗