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Biomedical subjects

I Sato

Publications and source records attributed to I Sato.

At least 163 records · Page 9Linked to original sources
PubMed1998

Immunocytochemical study of the maxilla and maxillary sinus during human fetal development.

We quantitatively examined the distribution of the proliferating cell nuclear antigen (PCNA), which is associated with cell division, and of components of the ECMs (collagen types I and III, tenascin and osteonectin) in the immature zones at three sites: palatine, inferior and vertical surface region of the fetal human maxilla as well as the maxillary sinus (MS) at 12, 16, 20, 24, and 28 weeks gestation. The percentage of PCNA-positive cells was the highest at 16 weeks in the immature zones of maxilla. Tenascin and fibrillar collagens (collagen types I and III) were especially present in the cellular zone linked to the bone and cartilage matrices of the immature zones of the maxillary bone at 20-24 weeks gestation. The osteonectin was detected on the maxillary bone from 24 weeks. These distributions of ECMs revealed the specific and contrasting profiles of development in the human maxillary bone and might reflect the formation of paranasal sinus as MS.

Cell Count↗
PubMed1998

Simvastatin, a potent HMG-CoA reductase inhibitor, inhibits the proliferation of human and bovine endothelial cells in vitro.

We investigated in vitro effect of simvastatin, a potent 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, on the proliferation of human and bovine endothelial cells (EC) compared to that of bovine smooth muscle cells (SMC). Cells were cultured in a medium supplemented with 10% normal serum (FBS). Simvastatin at concentrations ranging from 0.1 microg/ml to 10 microg/ml were used. In each kind of cells the proliferation was markedly reduced at 1 microg/ml of simvastatin (P<0.01) which was accompanied by morphological changes in the cell shape. We conclude that simvastatin inhibits the proliferation of not only the smooth muscle cells but also the endothelial cells.

Animals↗
PubMed1997

Baculovirus-insect cell production of bioactive porcine FSH.

The in vitro and in vivo bioactivity of recombinant porcine FSH (rpFSH) produced from insect cells through use of a baculovirus expression system were studied and compared with those of natural FSH preparations. Determination of in vitro bioactivity, using the rat Sertoli cell aromatase bioassay, indicated that rpFSH is as active as purified pituitary FSH. Determination of in vivo bioactivity, using the mouse uterine weight bioassay, indicated that rpFSH is as active as purified pituitary FSH. Using the mouse Leydig cell testosterone bioassay, it was demonstrated that the intrinsic LH bioactivity of rpFSH is negligible. The increases in ovarian and uterine weight, and the stimulation in follicular growth in immature hypophysectomized rats induced by rpFSH supplemented with hCG were comparable to those induced by natural FSH preparations. Furthermore, rpFSH alone in hypophysectomized mice stimulated preantral follicular growth to preovulatory stages, and the subsequent injection of hCG caused ovulation. These results demonstrate that in vitro and in vivo biological characteristics of rpFSH produced from baculovirus-insect cells are indistinguishable from those of FSH isolated from natural sources.

Journal Article↗
PubMed1997

Morphological and histological analysis of the thoracic duct at the jugulo-subclavian junction in Japanese cadavers.

The macroscopic arrangement of the termination of the thoracic duct (TD) was examined in detail in Japanese cadavers, and the distribution of various types of collagen, tenascin, laminin, and fibronectin in the framework of the wall of the thoracic duct termination was demonstrated. We identified several branching patterns and pathways of the TD (i.e., those terminating 1) at the venous angle (Type A); 2) at the end of the internal jugular vein (Type B); 3) at the the external jugular vein (Type C); or 4) in a complex with various branches (Type D). The TD often divided into two or three trunks before or after passing beneath the left brachiocephalic vein. Compared with the main trunk of the TD, fewer muscle fibers, elastic fibers, specific compounds of the extracellular matrices, and valvular connective tissues were found near the termination of the TD and the valves of the TD and veins. Smooth muscle cells were arranged irregularly in each region of the TD.

Cadaver↗
PubMed1997

Development of a recording system for saliva pH with and complete denture by telemetry.

A new system for measuring saliva pH by radio telemetry was developed. The system was built into a lower complete denture and could operate for about 19 h. The maximum error in the range pH 5-8 was 0.15 pH, and the correlation when values were compared with those from a glass-electrode pH meter was 0.99. That this system operates successfully was confirmed in a clinical experiment.

Aged↗
PubMed1997

Extrapancreatic action of truncated glucagon-like peptide-I in Otsuka Long-Evans Tokushima Fatty rats, an animal model for non-insulin-dependent diabetes mellitus.

To clarify the mechanism(s) of the antidiabetic effects of truncated glucagon-like peptide-1 (GLP-1) in diabetics, we examined its insulinotropic and extrapancreatic effects in a newly established strain of spontaneously non-insulin-dependent diabetic (NIDDM) rats, Otsuka Long-Evans Tokushima Fatty (OLETF) rats, that received a continuous infusion of truncated GLP-1 620 pmol/d/kg (G group, n = 12) or of vehicle (V group, n = 12) for 4 weeks by Alzet pump. Nonfasting plasma glucose levels were significantly lower (P < .05) in the G group than in the V group (7.0 +/- 0.67 v 9.1 +/- 1.7 mmol/L), and fasting plasma immunoreactive insulin (IRI) levels were lower in the former than in the latter (0.63 +/- 0.31 v 0.78 +/- 0.25 nmol/L). At day 15 of infusion, the G group showed an attenuated plasma glucose response to an oral glucose load, but had plasma IRI levels comparable to those in the V group. A long-term infusion of truncated GLP-1 increased the glucose infusion rate (GIR) significantly (P < .05) during a euglycemic-hyperinsulinemic clamp test (59.0 +/- 14.8 mumol/kg/min for group G v 38.9 +/- 12.2 for group V), but hepatic glucose output (HGO) did not differ significantly for either group. Uptake of 2-deoxy-D-glucose (2DG) by peripheral muscles in the G group was as much as 2.4-fold higher than in the V group (5.52 +/- 2.04 v 2.29 +/- 0.97 mumol/100 g muscle weight/min). We conclude from these data that truncated GLP-1, in addition to its well-known incretin effect, is capable of augmenting insulin action in peripheral tissues of diabetics, which can contribute, in part, to improve glucose intolerance in OLETF rats.

Administration, Oral↗
PubMed1997

Calcium-to-creatinine ratio in spot urine samples in early pregnancy and its relation to the development of preeclampsia.

We investigated the relation between an alteration in calcium (Ca) excretion in early pregnancy and the risk of preeclampsia in 1,147 pregnant women. We measured Ca and creatinine (Cr) concentrations in spot urine samples obtained at 12 weeks or less of gestation. Seventy-one (6.2%) had hypertension alone, nine (0.8%) developed superimposed preeclampsia, 39 (3.4%) developed proteinuria alone, and 13 (1.1%) developed preeclampsia; 1,015 women did not develop hypertension or proteinuria. The Ca/Cr ratio was significantly reduced in the 39 women who eventually developed proteinuria (0.116 +/- .103) and 13 who developed preeclampsia (0.121 +/- .063) compared with 1,015 women who had neither hypertension nor proteinuria (0.158 +/- .239). The relative risk of development of preeclampsia, proteinuria, or superimposed preeclampsia was 1.98 (95% confidence interval, 1.22 to 3.22) for women with a Ca/Cr ratio less than the 30th percentile (0.082) compared with women with a Ca/Cr ratio greater than the 30th percentile. These results suggest that preeclampsia may be related, in part, to a relative Ca intake deficiency. Determination of the Ca/Cr ratio in spot urine samples in the first trimester is of only limited clinical value for identifying women with an increased risk of preeclampsia.

Biomarkers↗
PubMed1997

Decrease in cytochrome c oxidase activity detected cytochemically in the placental trophoblast of patients with pre-eclampsia.

This study was designed to explore the possible relationship between cytochemically detectable cytochrome c oxidase (COX) activity in the trophoblast and placental dysfunction in patients with pre-eclampsia. Fifteen placentae (10 from women with an uncomplicated pregnancy and five from patients with pre-eclampsia) were involved in this study. Localization of COX activity in the placental trophoblast was determined by ultrastructural enzyme cytochemistry using DAB as a capturing agent. COX activity was observed in the intracristal spaces and intermembrane spaces of trophoblastic mitochondria. The number of mitochondria positive for COX staining was decreased markedly in the placentae of the women with pre-eclampsia. Trophoblastic mitochondrial dysfunction may be present in placenta of patients with pre-eclampsia.

Electron Transport Complex IV↗
PubMed1997

Comparison of the long-term effects of oral estriol with the effects of conjugated estrogen, 1-alpha-hydroxyvitamin D3 and calcium lactate on vertebral bone loss in early menopausal women.

We investigated the long-term effects of oral estriol (E3) on bone mineral density (BMD) at the lumbar spine and biochemical indices of bone turnover in early menopausal women. We studied 64 healthy early menopausal women who were treated for 24 months with 2.0 mg E3 plus 2.5 mg medroxyprogesterone acetate daily (E3 group, n = 15), 0.625 mg of conjugated estrogen plus 2.5 mg medroxyprogesterone acetate daily (CE group, n = 19), 1.0 microgram 1-alpha-hydroxyvitamin D3 daily (D3 group, n = 13), or 1.8 g calcium lactate containing 250 mg of elemental calcium daily (Ca group, n = 17). The BMD at the third lumbar vertebra was determined by quantitative computed tomography, and serum levels of osteocalcin (OC) and total alkaline phosphatase (Alp), as well as urinary ratios of calcium-to-creatinine (Ca/Cr) and hydroxyproline-to-creatine (Hyp/Cr), were evaluated at baseline and every 6 months. After 24 months of treatment, the BMD decreased significantly by 12 +/- 4.5% (mean +/- S.E.) in the D3 group and 14 +/- 2.5% in the Ca group, but not in the E3 group (-4.1 +/- 4.8% from baseline) and in the CE group (-0.9 +/- 3.2% from baseline). The serum levels of Alp and OC decreased or remained unchanged in the E3 and CE groups, but increased in the D3 and Ca groups. The urinary Ca/Cr was decreased in the E3 and CE groups, but not in the D3 and Ca groups. The urinary Hyp/Cr decreased in the CE group, was unchanged in the E3 and D3 groups, and increased in the Ca group. Uterine bleeding occurred less frequently in the E3 than in the CE group (2.4 +/- 4.2 versus 13.1 +/- 14.8 days/person per year, P < 0.001). The bone-preserving effect of 2.0 mg of oral E3 was comparable to that of 0.625 mg of conjugated estrogen and was superior to that of 1.0 microgram 1-alpha-hydroxyvitamin D3 and 1.8 g Ca. Our findings suggest that a reduction in bone turnover in the E3 group may have contributed to the preservation of bone.

Administration, Oral↗
PubMed1997

Accuracy and utility of a new reflectance pulse oximeter for fetal monitoring during labor.

OBJECTIVE: To evaluate the accuracy of a new pulse oximeter in estimating the oxyhemoglobin (O2Hb) concentration in fetal arterial blood (SaO2) with either a high concentration of hemoglobin F (HbF) or a low concentration of O2Hb during labor. PATIENTS AND METHODS: Fetal forehead arterial oxygenation was determined in 44 fetuses by reflectance pulse oximeter (SpO2) during labor and was compared with SaO2 determined immediately after birth. Because HbF has little or no known effect on pulse oximetry, but does affect the laboratory multiwavelength "CO-oximeter" type reading, the SaO2 was corrected by HbF concentration. SpO2 and SaO2 were simultaneously measured in five hypoxic adult volunteers achieved by inhaling 11% oxygen. RESULTS: A gradual decline in HbF concentration was seen during weeks 37 to 40 of gestation. HbF concentration varied near term, ranging between 53 and 88% of the fetal hemoglobin concentration (mean +/- SD = 74.6 +/- 6.3%). This alteration produced a lower %O2Hb percent by 4% at the most. The corrected SaO2 in cord blood correlated with fetal SpO2 (y = 0.974, x -7.279, r = 0.90). In five adults, SpO2 reflected well SaO2 with a mean +/- SD of bias of -1.1 +/- 2.9%. CONCLUSIONS: SpO2 determined by a new reflectance pulse oximeter at the end of labor correlated with an immediate post-natal cord arterial blood sample before the first breath, with a mean and SD of bias of 8.5 +/- 6.2%. Reflectance pulse oximetry is a useful tool for continuous noninvasive monitoring of the fetal oxygen status during labor.

Adult↗
PubMed1997

Sparfloxacin in the treatment of leprosy patients.

Seven men (age range, 20-33 years) with leprosy visited our dermatologic clinic at Yokohama City University Hospital (Table 1) and were entered into a trial of sparfloxacin (SPFX), 100-200 mg daily for up to 1 year. Five patients were Japanese Brazilians or Paraguayan from South America, and two patients were Filipinos. Examination procedures included a detailed medical history, pretreatment, clinical examinations, and body charting of the characteristic skin lesions, areas of anesthesia, and enlarged peripheral nerves. There were no deformities observed in any patient. All had presented with eruptions and neurologic problems. The diagnosis of leprosy and its type were determined by the above examination, skin smear, and histopathologic study, as well as Mitsuda reaction. The first patient came from the Philippines and presented to our clinic in 1993. There were many elevated erythemas with central healing on his whole body. Sensory nerves were impaired. His type was lepromatous (LL) leprosy. The second patient was followed for only 1 month because of a change in residence. The third and fourth patients were brothers. The fifth patient came from Paraguay. The sixth patient was from the Philippines. The seventh patient came to our clinic in April 1995.

Adult↗
PubMed1997

Cellular and subcellular localization of nicotinamide adenine dinucleotide phosphate diaphorase activity.

OBJECTIVE: To determine the cellular and subcellular distribution of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) in the human placenta and thereby to shed light on the possible role of nitric oxide (NO) and NO synthase in this tissue. METHODS: NADPH-d activity in 10 term placenta and in 10 first-trimester placentas was examined by enzyme histochemistry and by both light microscopy and electron microscopy. RESULTS: Light microscopy revealed that NADPH-d activity was marked in the syncytiotrophoblasts, moderate in the endothelium of cord vessels, and weak in the amniotic epithelia and chorionic trophoblasts. At the electron-microscopic level, NADPH-d activity was apparent as small patches distributed throughout the cytoplasm of the syncytiotrophoblasts. CONCLUSION: NO might be generated in the syncytiotrophoblast of the human placenta and might play a role in the regulation of placental hemodynamics or in the signaling between the syncytium and the villous mesenchyme.

Amnion↗
PubMed1997

Risks associated with cesarean sections in women with placenta previa.

OBJECTIVE: To investigate the risks associated with cesarean section performed because of placenta previa. METHODS: We retrospectively reviewed the records of 88 women with singleton pregnancies complicated by placenta previa who underwent cesarean sections and those of 176 (control) women with singleton pregnancies who required cesarean section because of complications other than placenta previa. RESULTS: The duration of gestation was 35.3 +/- 3.6 weeks for subjects with placenta previa and 36.9 +/- 3.8 weeks for the control subjects. The mean birth weight was 2,650 g +/- 75 g for infants of women with placenta previa and 2,644 g +/- 38 g for infants of the control subjects. Blood loss during surgery was greater for women with placenta previa than for the control subjects (1,154 ml +/- 924 ml vs 632 ml +/- 357 ml, p < 0.001). Blood transfusion was required in 13 of 88 (15%) women with placenta previa, compared with 4 of 176 (2.3%) of the control subjects (p < 0.001). An emergency cesarean hysterectomy was performed on 4 of the 88 (4.5%) women with placenta previa, and in none of the control subjects (p < 0.05). The Apgar score was < or = 7 at 5 minutes in 17 infants of the 88 (22%) women with placenta previa, compared with 17 infants of the 176 (11%) control subjects among infants born at > or = 33 weeks' gestation (p < 0.05); among infants with a birth weight > or = 2,000 g, the corresponding numbers were 15 (21%) and 13 (9.2%), respectively (p < 0.05). CONCLUSIONS: Cesarean section in the women with placenta previa was associated with increased blood loss, resulting in a blood transfusion rate 6.5 times higher than in the control subjects. These findings suggest that placenta previa might adversely affect the neonatal outcome.

Adult↗
PubMed1997

Fetal heart rate decelerations precede a decrease in fetal oxygen content.

To determine the relationship between abnormal fetal heart rate (FHR) patterns, fetal oxygen content by reflectance pulse oximetry, and the effects of maternal oxygen administration, 158 intrapartum women consisting of 120 women with normal FHR patterns, and 38 women with varying degrees of variable FHR decelerations were examined. A new reflectance pulse oximetry probe was attached to the fetal forehead to continuously monitor fetal oxygen saturation (SpO2) during labor. Oxygen was administered for 30 min at 5 liters/min by nasal canula in 32 women. No significant change in fetal SpO2 was seen in women with normal FHR patterns, but a significant decline in SpO2 was observed shortly before births. FHR decelerations less than 90 bpm occurred prior to the decline in fetal SpO2. Maternal oxygen administration was effective in increasing fetal SpO2 in fetuses with decreased SpO2 (SpO2 < 50%), but not in fetuses with high SpO2 (SpO2 > 60%). It is concluded that fetal SpO2 exhibits no change during normal labor but significantly declines shortly before birth, that relatively severe variable decelerations (<90 bpm) can decrease fetal SpO2, and that maternal oxygen treatment at 5 liters/min is effective in augmenting fetal oxygen tension in fetuses with decreased oxygen tension.

Female↗
PubMed1997

Elevation of the serum uric acid level preceding the clinical manifestation of preeclampsia in twin pregnancies.

To assess changes in the serum uric acid level in the third trimester of twin pregnancies, a total of 152 consecutive women with twin pregnancies were examined. Serum uric acid levels were analyzed in the women at varying gestational weeks in the presence or absence of preeclampsia. A receiver operating characteristic curve was used to determine the optimal cutoff value of serum uric acid between 30 and 31 weeks of gestation predicting subsequent development of preeclampsia. Forty-four women (29%) developed preeclampsia (preeclampsia group) at 33.2 +/- 1.9 weeks (mean +/- SD) and gave birth at 35.4 +/- 1.5 weeks of gestation. The remaining 108 women (71%) gave birth at 35.6 +/- 1.7 weeks of gestation (control group without preeclampsia). Serum uric acid levels rose gradually with advancing gestation in both groups. In the preeclampsia group, they were already increased at 30-31 weeks of gestation and corresponded to those seen in the control group at 37 weeks. The cutoff value at 30-31 weeks was 5.5 mg/dl, with a sensitivity of 73% and a specificity of 74%. These results suggest that an elevation in serum urate preceded the onset of preeclampsia. Determination of the serum level of uric acid between 30 and 31 weeks of gestation was useful for detecting a higher risk of late-onset preeclampsia in twin pregnancies.

Cohort Studies↗
PubMed1997

Effect of dietary zinc content on 65Zn metabolism in mice.

65Zn is one of the induced radioactive nuclides which are generated in power reactors. In the present experiment, several parameters of 65Zn metabolism were studied in mice maintained on diets with various zinc contents from 45 to 4,500 mg/kg to evaluate the efficacy of the dilution method for radiation protection against internal contamination with 65Zn. Gastrointestinal absorption of 65Zn was suppressed and its excretion accelerated as the dietary zinc content increased over a wide range. Clearance of 65Zn from tissues was generally accelerated by feeding mice a high-zinc diet, but that from the femurs was not affected by dietary zinc content. Zinc concentrations in tissues were regulated homeostatically up to a dietary zinc content of 1,350 mg/kg. Although a significant accumulation of zinc occurred in the liver, pancreas, kidneys, and femurs when mice were given 4,500 mg/kg diet, the concentrations except in the femurs recovered within a few days after switching to a normal-zinc diet. These results suggest that oral administration of zinc is effective for preventing the absorption and for enhancing the excretion of 65Zn to protect the body from internal radiation exposure with this isotope.

Animals↗