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Biomedical subjects

S Ota

Publications and source records attributed to S Ota.

At least 91 records · Page 5Linked to original sources
PubMed1998

Neonatal urinary ascites caused by urinary tract obstruction: two case reports.

Two cases of neonatal urinary ascites are reported, one (case 1) caused by posterior urethral valves associated with right vesicoureteral reflux, and the other (case 2) secondary to bilateral obstructed megaureter--a very rare cause. Abdominal distension, electrolyte imbalance, and an elevated BUN/serum creatinine ratio were noted at the time of hospitalization in both cases. These laboratory values promptly returned to normal after the establishment of appropriate urinary drainage, accomplished through bladder catheterization in case 1 and bilateral percutaneous nephrostomy in case 2. In case 1, transurethral resection of the posterior urethral valves was followed by resumption of normal urination. In case 2, bilateral ureteroneocystostomy with ureteral tapering was performed successfully. These are only the fifth and sixth cases of neonatal urinary ascites reported in the Japanese literature.

Ascites↗
PubMed1998

A mesenteric liposarcoma with production of granulocyte colony-stimulating factor.

A 77-year-old female was admitted to our hospital because of pyrexia and a right retroperitoneal mass. Leukocytosis and other inflammatory findings were noted. Bone-marrow aspiration revealed hypercellularity with no malignant cells. An additional mass was detected sonographically in the pelvis. The serum concentration of granulocyte colony-stimulating factor (G-CSF) was highly elevated (299 pg/ml). The tumors were removed at laparotomy, and the pelvic mass was found to arise from the ileocecal mesentery. Postoperatively, white blood cell count and serum G-CSF concentrations decreased to normal levels. The mesenteric tumor showed weakly positive immunostaining for human G-CSF, and Northern and polymerase chain reaction (PCR) analyses detected CSF and its mRNA in the mesenteric tumor.

Aged↗
PubMed1998

Establishment of a new human megakaryoblastic cell line, CMY, with chromosome 17p abnormalities.

A new megakaryoblastic cell line CMY was established from a Down's syndrome patient suffering from acute megakaryoblastic leukemia. The karyotypes of CMY showed deletion of chromosome 17 or the translocation of 17p, whereas the blasts of the patient did not reveal these abnormalities of chromosome 17 by conventional karyotype analysis. Blasts of the patient failed to respond to chemotherapy and complete remission could not be attained. The abnormalities of 17p became progressively predominant in the patient. These results suggest that the blasts of a minor clone which had the abnormalities of chromosome 17p might have existed in the patient from the beginning and CMY was established from the minor clone. Investigation of p53 gene by PCR-SSCP analysis revealed that blasts of the patient showed normal patterns, while CMY showed an abnormally migrating band in exon 5 alone. This result suggests that another novel oncogenic factor(s) besides p53 might be present on chromosome 17p and other tumor suppresser genes need to be studied.

Cell Differentiation↗
PubMed1998

[The intrarenal distribution of prostaglandin E2 and thromboxane A2 in the rat with unilateral ureteral obstruction or unilateral nephrectomy].

BACKGROUND: We evaluated the intrarenal distribution of prostaglandin E2 (PGE2) and thromboxane B2 (TxB2) on the rats that underwent unilateral ureteral obstruction (UUO), unilateral nephrectomy (UNX) or sham operation. METHODS: Male Sprague-Dawley rats were divided into three groups; left ureteral obstruction (UUO), left nephrectomy (UNX) and sham-operation (Control). They were sacrificed at 1, 3, 6, 12, 24 hours and Day 2, Day 3, Day 5, Day 7 and Day 9 after surgery. Intrarenal distribution of eicosanoids were immunohistochemically detected on both kidneys of UUO rats, and on right kidneys of UNX and Control rats. RESULTS: PGE2: In the obstructed kidneys, immunostained PGE2 increased in medullary interstitium at one hour to 6 hours, and in glomeruli and cortical interstitium at 6 hours. An increase of immunostained PGE2 was observed again in cortical interstitium at Day 3 to 5, and in medullary interstitium at Day 2 to 5. In the intact opposite kidneys, expression of immunostained PGE2 increased in glomeruli at Day 5 to 7, and in medullary interstitium at Day 3 to 5. In UNX, immunostained PGE2 increased in the medullary interstitium of the remnant kidneys at 3 hours and Day 3 to 7. On the other hand, an increase of immunostained PGE2 observed in glomeruli and cortical interstitium of these kidneys at Day 5 to 7. TxB2: In the obstructed kidneys, immunostained TxB2 increased in glomeruli and cortical interstitium at 6 hours, and in medullary interstitium at 3 to 12 hours. Predominant expression of TxB2 was observed in medullary interstitium at 3 hours compared to PGE2. We also observed an increase of immunostained TxB2 in cortical interstitium at Day 3 to 5, and in medullary interstitium at Day 2 to 5. In the intact opposite kidneys, immunostained TxB2 increased in medullary interstitium at 3 hours and Day 3. In the remnant kidneys of UNX, an increase of immunostained TxB2 was demonstrated in glomeruli at 6 hours and Day 7, and in medullary interstitium at 3 to 6 hours and Day 3 to 7. CONCLUSION: In the obstructed kidneys, imbalance between PGE2 and TxA2 may contribute to the progression of renal injuries. The fact that expression patterns of these eicosanoids in the opposite kidneys of UUO different from that of the remnant kidneys of UNK, even though both were similarly associated with functional loss of contralateral kidneys, suggested that the opposite kidneys of UUO were affected by any additional factors different from that responsible for the remnant kidneys of UNK.

Animals↗
PubMed1998

[Bone marrow relapse in high-risk pediatric patients with acute lymphoblastic leukemia: a comparison of relapse times and initial clinical features of patients on different protocols. Children's Cancer and Leukemia Study group (CCLSG)].

To clarify the efficacy of modern intensive chemotherapy for ALL patients with unfavorable features, we compared the time to failure and initial clinical features of children who relapsed in the bone marrow or combined sites, as documented by early CCLSG studies (H811 and H851; 1981-1987) and later studies (H874 and H/HH911; 1987-1993) concerning high-risk ALL patients. In the later studies patients outcomes with new intensive regimens employing early intensification and reinduction therapy were apparently better than those of patients in the early studies with conventional regimens. When we compared the number of relapsed patients based on duration of first remission, we found that the improved outcomes for patients in the later studies were due to a decrease in the number who relapsed 7-36 months after the start of treatment (intermediate relapse), and that the percentage of those who relapsed within the first 6 months of therapy (early relapse) was higher. Patients with high initial WBC counts tended to relapse much earlier than those with low initial WBC counts. However, in the later studies, patients with high WBC counts often relapsed after the termination of therapy (late relapse). These results suggest that the intensive chemotherapy regimens used in the later studies can prevent the development of drug resistant leukemic clones, except in extremely high-risk patients likely to relapse within the first 6 months of therapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Effect of caffeine on mucus secretion and agonist-dependent Ca2+ mobilization in human gastric mucus secreting cells.

Caffeine is known to stimulate gastric acid secretion, but, the effects of caffeine on gastric mucus secretion have not been clarified. To elucidate the action of caffeine on gastric mucin-producing cells and its underlying mechanism, the effects of caffeine on mucus glycoprotein secretion and agonist-induced [Ca2+]i mobilization were examined in human gastric mucin secreting cells (JR-I cells). The measurement of [Ca2+]i using Indo-1 and the whole cell voltage clamp technique were applied. Mucus glycoprotein secretion was assessed by release of [3H]glucosamine. Caffeine by itself failed to increase [Ca2+]i and affect membrane currents, while it dose-dependently inhibited agonist (acetylcholine (ACh) or histamine)-induced [Ca2+]i rise, resulting in inhibiting activation of Ca2+-dependent K+ current (I(K.Ca)) evoked by agonists. The effect of caffeine was reversible, and the half maximal inhibitory concentration was about 0.5 mM. But, caffeine did not suppress [Ca2+]i rise and activation of I(K.Ca) induced by A23187 or inositol trisphosphate (IP3). Theophylline or 3-isobutyl-1-methyl-xanthine (IBMX) did not mimic the effect of caffeine. Caffeine failed to stimulate mucus secretion, while it significantly decreased ACh-induced mucus secretion. These results indicate that caffeine selectively inhibits agonist-mediated [Ca2+]i rise in human gastric epithelial cells, probably through the blockade of receptor-IP3 signaling pathway, which may affect the mucin secretion.

Caffeine↗
PubMed1997

Antioxidant defenses of cultured colonic epithelial cells against reactive oxygen metabolites.

Reactive oxygen metabolites produce colonic epithelial cellular injury. The present study evaluated the protective role of cellular superoxide dismutase, catalase, and glutathione (GSH) redox cycle in cultured rabbit colonic cells. Cultured rabbit colonic epithelial cells were exposed to reactive oxygen metabolites generated by hypoxanthine (1 mM) and xanthine oxidase (1 mU/ml) for up to 5 h. Cytotoxicity was quantified by measuring 51Cr release from prelabeled cells. Pretreatment with diethyldithiocarbamate (inhibitor of superoxide dismutase) reduced activity of cellular superoxide dismutase and increased 51Cr release caused by hypoxanthine/xanthine oxidase from colonic cells. Pretreatment with diethyl maleate (covalently binds GSH as catalyzed by GSH transferase), or buthionine sulfoximine (inhibitor of gamma-glutamylcysteine synthetase) decreased cellular GSH and enhanced reactive oxygen metabolites induced injury. Pretreatment with bis(chloroethyl)-nitrosourea (inhibitor of GSH reductase) inhibited activity of GSH reductase and increased 51Cr release from colonic cells. Preincubation with aminotriazole (inhibitor of catalase) reduced cellular catalase, but did not affect cellular injury. Therefore, we concluded that both cellular superoxide dismutase and the GSH redox cycle appeared to play a role in detoxifying reactive oxygen metabolites and that cellular catalase may be less important in rabbit colonic epithelial cells.

Animals↗
PubMed1997

Autonomic responses to orthostatic stress in head-up tilt testing: relationship to test-induced prolonged asystole.

BACKGROUND: Prolonged asystole is sometimes an extreme manifestation of neurally mediated syncope. HYPOTHESIS: To investigate the mechanism of head-up tilt testing-induced prolonged (life-threatening) cardiac asystole, we measured temporal changes in frequency domain heart rate variability indices in 25 patients with syncope of undetermined etiology. METHODS: Head-up tilt testing (80 degrees) was performed in 25 patients for up to 40 min or until asystole or syncope occurred. Three patients (Group 1; 37 +/- 13 years, 1 man 2 women) had an episode of prolonged cardiac asystole (> or = 10 s) during testing, necessitating cardiopulmonary resuscitation. Syncope, but no asystole, was induced in 10 patients (Group 2; 48 +/- 31 years, 6 men, 4 women), and 12 patients (Group 3; 55 +/- 20 years, 5 men, 7 women) failed to show asystole or syncope during testing. Power spectra of low (0.04-0.15 Hz) and high (0.15-0.40 Hz) frequency, and total (0.01-1.00 Hz) frequency spectra were measured in consecutive 2 min segments throughout the test. RESULTS: Maximally changed values in heart rate, systolic blood pressure, and heart rate variability indices during testing were compared among the three groups (maximally changed values did not include the values during tilt-induced symptoms). High frequency spectra in Groups 2 and 3, but not in Group 1, decreased during the test. High frequency spectra, low frequency spectra, and total spectra in Group 1 were significantly higher than those in Groups 2 and 3 during testing. In Group 1 patients, findings at test-induced asystole were consistent with exaggerated sympathetic and concurrent persistent parasympathetic activity. CONCLUSION: Unusual autonomic responses to orthostatic stress can cause prolonged asystole, and this autonomic nerve dysregulation may relate to asystolic episodes associated with cardiovascular collapse.

Adult↗
PubMed1997

Hydrogen peroxide-mediated cytotoxicity to cultured colonic epithelial cells.

Reactive oxygen metabolites (ROM) contribute to colonic cellular injury, in certain pathophysiological conditions. We investigated the role of iron and individual metabolites in their cytotoxicity to cultured colonic epithelial cells from adult white rabbits. Reactive oxygen metabolites, enzymatically generated by hypoxanthine/xanthine oxidase, have a direct cytotoxic effect on cultured colonic epithelial cells. This cellular injury was inhibited by catalase but not SOD. Damage was not aggravated by ferrous iron or EDTA-chelated iron. Such damage was prevented by chelating intracellular iron, but not extracellular iron. These results suggest that H2O2 is more toxic to colonic epithelial cells than 02.- and OH. in the extracellular space. H2O2 enter the intracellular space and is converted to the more reactive and harmful OH. leading to cellular injury in the presence of intracellular iron.

Animals↗
PubMed1997

Hydrometrocolpos with ectopic vaginal opening to the bladder. A case report.

A case of hydrometrocolpos with vaginal opening to the bladder is presented. A newborn female presented abdominal distention and postaxial polydactyly at birth. Clinical investigation revealed hydrometrocolpos, precocious puberty, urogenital sinus and other multiple malformations. The vagina was open to the bladder with a small orifice. Vaginal pull-through surgery and closure of the communication was performed. Over a hundred cases of hydrometrocolpos have been reported previously. However, we could not find a case of hydrometrocolpos with vaginal opening to the bladder among them.

Female↗
PubMed1997

The Cbl protooncogene product: from an enigmatic oncogene to center stage of signal transduction.

The c-cbl protooncogene was first identified as the cellular homologue of a viral oncogene v-cbl that induces pre-B lymphomas and myeloid leukemias in mice. Until recently, the biochemical basis for Cbl's transforming potential and its physiological role remained unclear. However, a convergence of biochemical studies in mammalian cells and genetic studies in C. elegans and Drosophila has now identified Cbl as a negative regulator of tyrosine kinase signaling. The N-terminal transforming region of Cbl (Cbl-N) and an adjacent RING finger domain are the elements most conserved during evolution. The Cbl-N region has now been shown to contain a novel phosphotyrosine-binding (PTB) domain that directly interacts with autophosphorylated tyrosine kinases via a D(N/D)XpY motif. A critical role of the PTB domain in Cbl function is demonstrated by the localization of a loss-of-function mutation in C. elegans Cbl homologue SLI-1 within this region. The corresponding mutation in human Cbl inactivates the PTB domain function and abrogates Cbl-mediated regulation of tyrosine kinase function. Recent studies have also identified a novel signaling pathway initiated by the interaction of mammalian Cbl proteins with the SH2 domains of Crk adaptor molecules, which results in Cbl's linkage with C3G, a guanine nucleotide exchange protein for Rap1 family of small G-proteins. Presently, Rap1 is thought to antagonize Ras function, although Rap1-specific targets have emerged recently. Thus, recent advances have firmly placed the little known protooncoprotein Cbl on the center stage of tyrosine kinase-mediated signal transduction.

Amino Acid Sequence↗
PubMed1997

Reducing nurses'. Workload using a computerized nursing support system linked to the hospital information system.

A computerised nursing support system (CNSS) linked to the hospital information system (HIS) was developed and has been in use for one year, in order to reduce the workload of nurses. CNSS consists of (1) a hand held computer for each nurse (2) desk-top computers in the nurses' station and doctors' rooms (3) a data server (4) an interface with the main hospital information system. Nurses enter vital signs, food intake and other information about the patients into the hand held computer at the bed-side. The information is then sent automatically to the CNSS data server, which also receives patients' details (prescribed medicines etc.) from the HIS. Nurses and doctors can see all the information on the desk-top and hand held computers. This system was introduced in May 1995 into a university hospital ward with 40 beds. A questionnaire was completed by 23 nurses before and after the introduction of CNSS. The mean time required to post vital data was significantly reduced from 121 seconds to 54 seconds (p < 0.01). After three months 30% of nurses felt CNSS had reduced their workload, while 30% felt it had complicated their work; after five months 70% noted a reduction and 0% reported that CNSS had made their work more complex. The study therefore concludes that the interface between a computerised nursing support system and the hospital information system reduced the workload of nurses.

Humans↗
PubMed1997

Followup study of renal function in children with reflux nephropathy after resolution of vesicoureteral reflux.

PURPOSE: We evaluated data collected for 10 years on children with reflux nephropathy to identify a means of predicting the prognosis. MATERIALS AND METHODS: A total of 15 boys and 13 girls were enrolled in this study at least 2 years after surgical and spontaneous resolution of vesicoureteral reflux in 25 and 3 patients, respectively. They were followed for more than 10 years and renal function was periodically evaluated. Urinary beta 2-microglobulin, alpha 1-microglobulin, N-acetyl-beta-D-glucosaminidase, microalbumin and 99mtechnetium dimercapto-succinic acid uptake were measured. RESULTS: Of the 28 patients 12 had high levels of urinary alpha 1-microglobulin during followup, including all 7 in whom renal function deteriorated. In 3 children with elevated alpha 1-microglobulin urinary microalbumin gradually increased after puberty. Although elevated levels of urinary beta 2-microglobulin, N-acetyl-beta-D-glucosaminidase and microalbumin were also observed, they were less predictive of renal function than alpha 1-microglobulin. CONCLUSIONS: These results suggest that elevated urinary levels of alpha 1-microglobulin may predict the risk of abnormal renal function in children with reflux nephropathy even before the appearance of significant proteinuria.

Acetylglucosaminidase↗
PubMed1997

Interleukin-1 as an autocrine stimulator in the growth of human ovarian cancer cells.

The role of interleukin-1 (IL-1), a multifunctional cytokine which mediates important immune responses, was investigated in the growth of ovarian cancer cell lines in vitro. The messenger RNA for IL-1 alpha and IL-1 beta was expressed in six and four ovarian cancer cell lines, respectively out of eight. Measurement of IL-1 in the eight cell lines by enzyme-linked immunosorbent assay revealed that two lines, MCAS and TYK-nu, secreted a high amount of IL-1 alpha, but that none secreted IL-1 beta after 72 hours of incubation. The growth of these cells was significantly stimulated by the addition of recombinant IL-1 alpha (rIL-1 alpha) in a concentration-dependent manner in a 96 hour culture. The maximum response was obtained with 10 ng/ml of IL-1 alpha by counting the viable cell number using trypan blue. [3H]-thymidine incorporation by these cells was also stimulated by a 72 hour incubation with rIL-1 alpha. The spontaneous growth of these cells was inhibited by the addition of anti-IL-1 alpha antibody, anti-IL-1 receptor antibody or IL-1 receptor antagonist. These cells expressed two classes of IL-1 binding receptors on their surface as detected by [125I]-labeled rIL-1 alpha. These results indicate that IL-1 alpha is an autocrine growth stimulator for some ovarian cancer cells and suggest that IL-1 alpha plays an important role in the progression of this disease.

Antibodies, Monoclonal↗
PubMed1997

Urinary excretion of epidermal growth factor in children with reflux nephropathy.

PURPOSE: We determined urinary levels of epidermal growth factor in children with reflux nephropathy to evaluate the clinical significance of urinary epidermal growth factor. MATERIALS AND METHODS: We studied 59 boys and 41 girls 3 to 15 years old with reflux nephropathy, and 64 boys and 36 girls 3 to 15 years old who were healthy. Levels of urinary epidermal growth factor were determined by sandwich enzyme immunoassay using spot urine samples. We also determined the levels of serum creatinine, urinary alpha 1-microglobulin and urinary microalbumin. Absolute values of function of the left and right kidneys were assessed by 99mtechnetium dimercapto-succinic acid (DMSA) uptake. RESULTS: Levels of urinary epidermal growth factor gradually decreased with age in healthy children. There were low levels of urinary epidermal growth factor in 20 of the 44 patients (45%) with unilateral low DMSA uptake and 18 of the 19 (95%) with low total DMSA uptake (right and left uptakes). Urinary epidermal growth factor significantly correlated with serum creatinine (R = -0.702, p < 0.0001), urinary alpha 1-microglobulin (R = -0.606, p < 0.0001), urinary microalbumin (R = -0.708, p < 0.0001) and total DMSA uptake (R = 0.744, p < 0.0001). CONCLUSIONS: These results suggest that urinary epidermal growth factor may be a useful clinical tool to monitor functional nephron mass in children with reflux nephropathy.

Adolescent↗
PubMed1997

Bone metabolism and daily physical activity in women undergoing hemodialysis.

BACKGROUND: We investigated the relationships between bone mineral density (BMD) and bone metabolic markers in 41 Japanese women (age range, 23 to 85 years; mean, 61; SD, 16) undergoing hemodialysis, and the relationship between BMD and daily physical activity with nutritional state in those patients. METHOD: The patients were divided into a group with hyperparathyroidism (intact parathyroid hormone [PTH] > or = 300 pg/mL, n = 9) and a group without hyperparathyroidism (intact PTH < 300 pg/mL, n = 32). Total BMD and spinal BMD (regional evaluation) were measured using dual-energy X-ray absorptiometry. We determined serum concentrations of intact PTH, osteocalcin (bone Gla protein) and alkaline phosphatase as markers of bone formation, and serum tartrate-resistant acid phosphatase (TRAP) as a marker of bone resorption. Mean energy expenditure per day was measured by calorie counters worn by the patients, and serum levels of total protein, albumin, cholesterol, ferritin, and blood urea nitrogen were measured as indices of nutritional status. RESULTS: In the group without hyperparathyroidism, 9 patients had a spinal BMD < 0.85 g/cm2 and were considered to be at risk for bone fracture. In this group, a significant correlation was observed between total BMD and TRAP (r = -0.52, p = 0.004). Age, duration of hemodialysis, dry body weight, energy expenditure per day, and serum total protein levels were correlated with total BMD and spinal BMD, using multiple regression analysis (p < 0.0001). CONCLUSIONS: In patients with low BMD, the bone turnover tended toward bone resorption rather than formation, without strong influence by parathyroid function. Energy expenditure showed a strong relationship to the total BMD (r = 0.32, F = 18.5), which appeared to improve bone turnover.

Adult↗