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Biomedical subjects

K Hata

Publications and source records attributed to K Hata.

At least 181 records · Page 10Linked to original sources
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

Mechanoenergetics of negative inotropism of ventricular wall vibration in dog heart.

Mechanical vibration depresses cardiac contractility. We studied the mechanoenergetic effects of this negative inotropism in the left ventricle (LV) of an isolated, cross-circulated dog heart preparation. We took full advantage of the mechanoenergetic relationship among the LV end-systolic elastance (Emax, contractility index), systolic pressure-volume area (PVA), and myocardial oxygen consumption (VO2). PVA is a measure of the total mechanical energy that cardiac contraction generates. PVA correlates closely with VO2. The VO2 intercept of the VO2-PVA relation reflects the VO2 component for excitation-contraction (E-C) coupling plus basal metabolism (PVA-independent VO2). VO2 above the PVA-independent VO2 reflects the VO2 component for mechanical contraction (PVA-dependent VO2). When we applied 70-Hz vibration of 2-mm amplitude to a LV wall region, it instantly decreased Emax and PVA by 20%, followed by a 10% decrease in VO2 at a fixed volume. However, the vibration neither lowered the VO2-PVA relation obtained at different LV volumes, unlike ordinary negative inotropism, nor changed its slope (1.88 +/- 0.23 vs. 1.86 +/- 0.23 x 10(-5) ml O2.mmHg-1.ml-1). The virtually zero delta PVA-independent VO2/delta Emax with vibration indicates a much smaller O2 cost of Emax than that seen with calcium and propranolol inotropism. These mechanoenergetics support the hypothesis that mechanical vibration primarily suppresses cardiac contractility without suppressing E-C coupling.

Animals↗
PubMed1996

Interleukin-1 receptor antagonist in cord blood: effects of labor and fetal distress.

OBJECTIVE: To evaluate the effect of labor pains or fetal distress on concentrations of interleukin-1 receptor antagonist (IL-1ra) in cord blood. METHODS: Umbilical cord interleukin-1 beta (IL-1 beta) and IL-1ra were measured in 24 normal appropriately grown newborns delivered vaginally (VD group), 10 normal appropriately grown newborns delivered by elective cesarean section (ECS group), and 5 appropriately grown newborns with fetal distress (FD group). Umbilical cord arterial blood pH and PO2 were also measured. RESULTS: Umbilical artery blood pH and PO2 in the VD group were not significantly different from those in the ECS group. Umbilical artery blood pH and PO2 in the FD group were significantly lower than those in the VD group (p < 0.05). Umbilical artery blood pH in the FD group was significantly lower than that in the ECS group (p < 0.05), but no significant difference for umbilical artery blood PO2 was found between the FD and ECS groups. IL-1 beta levels were undetectable in the three groups of neonates. There were no significant differences for concentrations of IL-1ra in cord blood among the groups. CONCLUSION: These results suggest that the labor pain or fetal distress does not affect concentrations of IL-1ra in cord blood.

Female↗
PubMed1996

Mathematical modeling of fetal organ growth using the Rossavik growth model. V. Cerebellum.

Growth of the fetal cerebellum was monitored by transverse cerebellar diameter (CD) from 14 to 39 weeks menstrual age in 125 Japanese fetuses. The growth curve for this parameter was determine using a Rossavik growth model [p = c(t)k & (t)]. An R2 value of 95.5% was obtained for CD. Variability analysis indicated a progressive increase in variability with fetal age for this parameter. Variability data were used with the growth curve model to determine a standard curve for this parameter. This standard curve provides a superior means to evaluate normal fetal cerebellar growth in the fetus and to identify cerebellar abnormalities in utero.

Cerebellum↗
PubMed1996

Cord blood cytokines and soluble adhesion molecules in vaginal and cesarean delivered neonates.

OBJECTIVE: Our purpose was to evaluate the effect of labor pain on the concentrations of cytokines and soluble adhesion molecules in cord blood. METHODS: Umbilical cord interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-alpha), granulocyte elastase (GEL), intercellular adhesion molecule-1 (ICAM-1), and endothelial lymphocyte adhesion molecule-1 (ELAM-1) were measured in 21 normal appropriately grown newborns delivered vaginally (VD group), and 20 normal appropriately grown newborns delivered by elective cesarean section (ECS group). Umbilical cord arterial blood pH and PO2 were also measured. RESULTS: Umbilical artery blood pH and PO2 in the VD group were not significantly different from those in the ECS group. There were no significant differences for concentrations of IL-6, IL-8, TNF-alpha, GEL, ICAM-1, and ELAM-1 in cord blood between VD and ECS groups. CONCLUSION: These results suggests that labor pains do not affect the concentrations of cytokines and soluble adhesion molecules in cord blood.

Adult↗
PubMed1996

Interleukin-6, interleukin-8, and granulocyte elastase in newborns with fetal distress.

OBJECTIVE: Our purpose was to investigate the participation of cytokines and neutrophils in fetal distress. STUDY DESIGN: Umbilical cord serum interleukin-6 (IL-6), interleukin-8 (IL-8), and plasma granulocyte elastase (GEL) were measured in 30 normally grown newborns without fetal distress (Group A), 10 growth-retarded newborns without acute fetal distress (Group B), 5 normally grown newborns with fetal distress (Group C), and 5 growth-retarded newborns with fetal distress (Group D). Umbilical arterial blood pH and PO2 were also measured. RESULTS: Umbilical arterial blood pH and PO2 in either Group C or Group D were significantly lower than those in either Group A or Group B. The concentration of IL-6 in Group D was significantly higher than that in either Group A, B, or C. The level of IL-8 in either Group C or Group D was significantly higher than that in either Group A or Group B. The concentrations of GEL in Group D was significantly higher than that in either Group A or Group B. CONCLUSION: This study suggests that fetal distress in utero causes an elevation of immune factors such as IL-6, IL-8 and GEL.

Acidosis↗
PubMed1996

Fetal ophthalmic artery blood flow velocity waveforms.

OBJECTIVE: To evaluate alterations in vascular impedance of the fetal ophthalmic artery (OA) with advancing gestation. STUDY DESIGN: Color Doppler flow imaging and pulsed Doppler ultrasonographic assessment were performed on 28 normal fetuses, at gestational ages ranging from 21 to 40 weeks. The pulsatility index (PI) was calculated for the OA and the middle cerebral artery (MCA). Optimal models for these PI values were determined by regression analysis. A normal range of PI values for both arteries was generated. RESULTS: In the OA, the model showed a parabolic pattern during pregnancy, as was the case for MCA. The predicted PI values for the OA were always lower than those for the MCA. CONCLUSION: Our study is the first to demonstrate alterations in regional vascular impedance of the fetal OA with advancing gestation. These data provide a foundation for the evaluation of fetal ocular circulation in normal and abnormal pregnancies.

Blood Flow Velocity↗
PubMed1996

Measurement of bone-specific alkaline phosphatase by an immunoselective enzyme assay method.

We evaluated a new immunoselective enzyme assay of bone-specific alkaline phosphatase (ALP). The monoclonal antibody used in this assay was raised against purified bone-specific ALP obtained from SAOS-2 human osteosarcoma cell line. Calibration was based on the enzyme's own activity. The relative activity of the antibody was 100% with bone ALP, 8.7% with liver ALP, and 0% with placental and intestinal ALPs. Intra- and inter-assay coefficients of variation were less than 4%. The sensitivity of the assay was 0.7 U/L, and the linearity extended from 2 to 140 U/L. The recovery of bone-specific ALP standard added to serum was 94-106%. The correlation coefficient between this method and the polyacrylamide gel (PAG) electrophoretic method was 0.94. The mean value of bone-specific ALP in 89 healthy adults (mean age 29 years, SD 5 years) was 18.5 U/L (SD 4.1 U/L). Interestingly, mean bone-specific ALP activities in 60 premenopausal women (mean age 39 years, SD 8 years) and 70 postmenopausal women (mean age 57 years, SD 5 years) were 20.3 U/L (SD 6.5 U/L) and 31.1 U/L (SD 11.1 U/L), respectively. The age-related increase in bone-specific ALP was significant and more pronounced in women (P < 0.01). We conclude that this new immunoassay of bone-specific ALP would be useful for clinical investigation of patients with osteoporosis or other metabolic diseases of bone.

Adult↗
PubMed1996

Differences in bone and vitamin D metabolism between primary hyperparathyroidism and malignancy-associated hypercalcemia.

Bone and vitamin D metabolism are examined in patients with primary hyperparathyroidism (1 degree HPT), humoral hypercalcemia of malignancy (HHM), and local osteolytic hypercalcemia (LOH) with normal renal function. Among the bone resorption markers, T scores of total deoxypyridinoline (Dpyd) were highest in HHM and were significantly higher than those in 1 degree HPT. Among the formation markers, T scores of osteocalcin (OC) were highest in 1 degree HPT but were negative in HHM. The elevation in total Dpyd was associated with an increase in OC in 1 degree HPT, and the ratios of total Dpyd/OC were similar to those in controls. In contrast, many patients with HHM and LOH exhibited elevated total Dpyd and suppressed OC with increased total Dpyd/OC ratios, but the ratios varied widely. Serum 1,25-dihydroxyvitamin D [1,25(OH)2D] was elevated in 1 degrees HPT but was suppressed in HHM and LOH at any serum Ca levels. These results demonstrate that increased bone resorption is associated with enhanced bone formation in 1 degrees HPT but are uncoupled in many of the HHM and LOH patients, and that total Dpyd/OC ratio can be a useful index to estimate the coupling state of bone. It is suggested that the reduction in serum 1,25(OH)2D cannot be explained by an elevation in serum Ca in HHM and LOH, and that the differences in bone and vitamin D metabolism in HHM and LOH from those in 1 degree HPT may be caused by a common mechanism such as the secretion of some cytokines from tumors.

Adult↗
PubMed1996

Effect of dehydroepiandrosterone sulfate on fetal middle cerebral artery flow velocity waveforms in term pregnancy.

OBJECTIVE: To investigate whether bolus injection of dehydroepiandrosterone sulfate (DHAS) is associated with changes in fetal middle cerebral artery flow velocity waveforms in term pregnancy. METHODS: Ten normal full-term pregnant women received the administration of a 200-mg intravenous dose of DHAS in 20 ml of 5% dextrose. Ten normal full term pregnant women received 20 ml 5% dextrose as controls. Color Doppler flow imaging and pulsed Doppler ultrasonographic assessments were made on fetuses in each group before and 10 min, 30 min, 60 min, 90 min. and 120 min after DHAS or dextrose administration. The pulsatility index (PI) values for the middle cerebral artery, and umbilical artery, and fetal heart rate were recorded. RESULTS: In the DHAS group, middle cerebral artery PI decreased from baseline by 24% (p<.05) after 10 min, and the mean reduction was 22% (p<.05) after 30 min. The PI returned to the baseline value 60 min later. In the control group, there was no change in middle cerebral artery PI. No change was found in umbilical artery PI or fetal heart rate in the control or DHAS group. CONCLUSION: DHAS induces a significant decrease in the fetal middle cerebral artery PI, which suggests a possible decrease in fetal cerebral vascular impedance in term pregnancy.

Adult↗
PubMed1996

Intratumoral blood flow analysis in ovarian cancer: what does it mean?

The objective of this study is to evaluate the significance of intratumoral blood flow in ovarian cancer. Forty-seven patients with histologically proved ovarian cancer underwent transvaginal gray scale sonography, and color and Doppler sonography before surgery. Intratumoral blood flow velocity waveforms obtained from architecture within the tumor were recorded, and resistive index and peak systolic velocity were calculated. Neither resistive index values nor peak systolic velocity values differed significantly among the histological diagnoses, regardless of stage (including metastatic tumor) or morphologic classification of tumor. These results suggest that intratumoral blood flow analysis in ovarian cancer cannot provide information on individual tumor characteristics.

Adolescent↗
PubMed1996

[Combination therapy with irinotecan and CBDCA for patients in terminal stage of ovarian carcinoma].

Combination chemotherapy with irinotecan and CBDCA was performed for two patients in the terminal stage of ovarian carcinoma. Every week, 75 mg.m-2 of irinotecan and 75-100 mg.m-2 of CBD CA were intravenously administered. Both patients showed a partial response. Diarrhea was not a characteristic side effect of irinotecan in this case. Dose limiting factors were leucopenia and thrombocytopenia.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

An autopsy case of abandoned infant body with severe destruction.

One case of infanticide and abandonment by the natural mother is presented. The body was extensively damaged, evidently by a fox. Fortunately, since the body showed less advanced putrefaction due to cold weather, it was possible to narrow down the cause of death and to detect the drug which had been forced down the victim's throat before the crime. However, our estimates of age and postmortem interval were erroneous. We comment as to why we were misled. Pathological problems associated with "aspiration of vomitus" are also discussed.

Age Determination by Teeth↗
PubMed1996

[Rapid detection and identification of human adenovirus directly from conjunctival scrapings by polymerase chain reaction and restriction fragment length polymorphism analysis].

Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis were combined for detection and identification of adenovirus (Ad), a common agent of conjunctivitis in Japan. Nested-PCR with two primer sets that hybridize to the conserved region for hexon protein of 14 prototypes of Ad serotype 1 to 8, 11, 14, 19, 37, 40, and 41, amplified 956 bps DNA fragment. The amplified fragments from 14 prototypes were completely differentiated with the combination of three restriction endonucleases, Eco T14I, Hae III, and Hin fI. We applied this new method to 70 conjunctival scrapings from patients with conjunctivitis, and compared the results with those of the combination of culture isolation and neutralization test. PCR was positive in 38 out of 70 samples (54.3%), whereas 33 of 70 samples (47.1%) were positive by cell culture. Compared with cell culture isolation, the PCR method had a sensitivity of 100% (33 of 33). Positive PCR samples were further classified into Ad 37 (44.7%), 3 (39.5%), 11 (7.9%), 8 (5.3%), and 4 (2.6%) by PCR-RFLP analysis. Of five samples that were PCR positive and cell culture negative, three samples were Ad 37 and two were Ad 8 by PCR-RFLP analysis. These differentiations of cell culture positive samples were identical to the results of the neutralization test. It took only about three days to detect and identify Ad by PCR-RFLP analysis, whereas it took at least two weeks by culture isolation and neutralization test. Our newly developed method of detecting and typing human Ad by PCR-RFLP analysis is more sensitive, accurate, and prompt than the conventional cell culture isolation and neutralization test.

Adenovirus Infections, Human↗
PubMed1996

Fabrication of cultured epithelium using oral mucosal cells and its clinical applications.

A cultured mucosal epithelium can be formed with living mucosal cells in vitro and used as a graft material. In this article, we described our culture methods for preparation of cultured mucosal epithelium as well as its biological characteristics compared with cultured skin epithelium. According to our results, cultured mucosal epithelium was formed earlier than cultured skin epithelium. Furthermore, the structure of cultured mucosal epithelium was maintained longer than that of cultured skin epithelium. Based on our findings from an in vitro study, we applied this cultured mucosal epithelium to the reconstruction of human skin and mucosal defects and succeeded in repairing the defects. We also present an overview of the problem relevant to the use of such methods.

3T3 Cells↗
PubMed1995

Endotoxin antagonism by a synthetic lipid A analogue, DT-5461, with low endotoxicity in human peripheral blood monocytes.

We examined the molecular mechanism of DT-5461-induced LPS antagonism in human peripheral blood monocytes. Dose-response studies revealed that LPS-induced IL-1 and TNF-alpha production was apparently totally suppressed in a competitive manner by a 10-fold excess of DT-5461. A 10-fold excess of DT-5461 significantly blocked the binding of FITC-LPS to the monocytes. DT-5461 suppressed IL-1 and TNF-alpha mRNA expression in LPS-activated monocytes. Western blots showed that DT-5461 suppressed the LPS-induced tyrosine phosphorylation of p42mapk/ERK2. These results suggested that the competitive binding inhibition and repression of early intracellular signaling involved in DT-5461-mediated LPS antagonism.

Adjuvants, Immunologic↗
PubMed1995

RNA polymerase III dependence of the human L1 promoter and possible participation of the RNA polymerase II factor YY1 in the RNA polymerase III transcription system.

From the general views of the eukaryotic transcription systems, L1 (or L1-like) retrotransposons that encode some proteins are unusual. L1, unlike other protein-coding elements, is transcribed through an internal promoter. And the L1 internal promoter, unlike other internal promoters, is thought to be RNA polymerase II (pol II) dependent, because the L1 transcript has a large size (approximately 6 kb), protein coding capacity and a 3' terminal polyadenylation signal followed by a poly(A) tail, and also because transcription from the promoter of Drosophila L1-like element jockey was highly sensitive to alpha-amanitin. However, our in vitro transcription study reveals that transcription from the human L1 promoter is highly sensitive to tagetitoxin, a selective inhibitor of RNA polymerase III (pol III), but insensitive to 1 micrograms/ml of alpha-amanitin, indicating that the human L1 promoter is pol III-dependent. The pol III dependence is further supported by our observation that L1 and pol III-dependent tRNA gene promoters share a common nuclear factor YY1. There is evidence that YY1 is also a pol II transcription factor. We thus propose that YY1 is a possible member of the pol III transcription system.

Base Sequence↗