Biomedical subjects
Publications and source records attributed to Y Otsubo.
At 16 weeks' gestation, ultrasonography demonstrated a band-like structure in the amniotic cavity of a 27-year-old woman. Color Doppler imaging revealed blood flow in this band-like structure and a diagnosis of a placenta with succenturiate lobe rather than an amniotic band was made.
OBJECTIVE: The aim of this study was to investigate plasma adenosine levels during normal pregnancy and to evaluate the possible roles of platelet activation and 5'-nucleotidase as causes of changes in adenosine levels. STUDY DESIGN: We measured plasma adenosine levels, the platelet activation markers beta-thromboglobulin and platelet factor 4, and 5'-nucleotidase activity, which catalyzes dephosphorylation from adenosine monophosphate to adenosine, in 34 nonpregnant women and 34 women with normal pregnancies in the third trimester. RESULTS: The mean plasma adenosine level in pregnant women was 0.59 +/- 0.08 micromol/L (mean +/- SEM), which was significantly higher than that found in nonpregnant women (0.18 +/- 0.04 micromol/L; P <.01). In pregnant women plasma beta-thromboglobulin levels, platelet factor 4 levels, and 5'-nucleotidase activity were significantly higher than in nonpregnant women (P <.05). CONCLUSION: The increase of plasma adenosine may be attributed at least in part to platelet activation and an increase of 5'-nucleotidase activity during normal pregnancy. This increase may be an endogenous compensatory mechanism that diminishes platelet activation and maintains vessel integrity during normal pregnancy.
We present here a case of B-cell-type mediastinal malignant lymphoma during pregnancy complicated by placental involvement. In this case, some nodular high-echo patterns were recognized in the placenta by ultrasonography. A cesarean section and resection of the mediastinal tumor were performed at 33 weeks and 6 days of gestation due to the deterioration of the dyspnea. A female infant weighing 1,868 g was delivered and she is now a healthy 2-year-old. The mother, however, died of the disease 1 month after surgery, due to progression of the tumor. The placenta showed numerous white firm nodules varying from 3 mm to 3 cm in diameter. The pathologic findings of both the mediastinal tumor and the placenta indicated primary mediastinal (thymic) B-cell lymphoma.
OBJECTIVE: The appropriate date of delivery in twin pregnancies is supposed to be earlier than that in singleton pregnancy. The aim of this study was to compare two strategies for managing twin pregnancies (i.e., immediate induction and expectant management). METHODS: Seventeen patients underwent immediately induced labor by administration of oral prostaglandin E(2) at 37 weeks, while 19 patients underwent expectant management. RESULTS: The average gestational age at delivery in the induction group was 37.5 +/- 0.4 weeks, significantly earlier than that in the expectant management group (39.0 +/- 1.1 weeks). However, there were no significant differences in the average birth weight between the two groups (2, 700 +/- 330 g in the induction group vs. 2,672 +/- 392 g in the expectant management group). The cesarean delivery rate in the induction group was 18%, not significantly different from that in the expectant management group (32%). The most common indication for cesarean section in the expectant management group was maternal infection, while there was no maternal infection in the induction group (p = 0.08). CONCLUSION: It may be acceptable do intervene in twin pregnancies earlier than in singleton pregnancies during term.
A polymer coil with weak affinity for the solid surface makes a flexible bridge between particles by reversible adsorption. When the coil size is comparable to particle diameter in solution, the suspensions flocculated by reversible bridging show shear-thickening flow in a narrow range of shear rates. The force generated by the rapid extension of bridges within the lifetime is responsible for the shear thickening. Although it is expected that the bridges become more flexible with increasing coil size, the polymers with high molecular weights do not necessarily give rise to shear thickening. The striking shear thickening is induced by polymers with molecular weights, Mw, of 2.5 x 10(5) and 4.5 x 10(5). The viscosity enhancement in the shear-thickening region is considerably suppressed for polymers with Mw = 7.5 x 10(5). From the sedimentation experiments, a large portion of the segments of a coil with Mw = 7.5 x 10(5) is adsorbed in train on the particle surface. The addition of small amounts of surfactant leads to an increase in the fraction of loops at the expense of trains and the bridges become more flexible. As a result, the flow of suspensions in the presence of surfactant becomes shear thickening. The rheology of suspensions flocculated by reversible bridging can be modified by a balance between loop and train fractions in a bridge. Copyright 1999 Academic Press.
Seven cases of parietal cephalocele and three cases of occipital cephalocele associated with abnormal venous drainage were evaluated, and the mechanism of the development for venous system was discussed from the embryological viewpoint. In parietal cephaloceles the abnormally draining vein, which corresponds to the straight sinus, ascended along the interhemisphere apart from the tentorium and emptied into the superior sagittal sinus below the cephalocele. The superior sagittal sinus formed the confluence, which was positioned high up. Intraoperative findings revealed that cephalocele penetrated the superior sagittal sinus at the midline. In the case of occipital cephalocele, the straight sinus followed a postero-superior course, to drain into the confluence just above the neck of cephalocele. The results of our study suggest that the causation of abnormal venous drainage in the great vein of Galen, the straight sinus and the superior sagittal sinus may be secondary, through interaction with a developmentally pre-existing cephalocele.
The effect of omega-3 fat emulsion on nitrogen retention and kinetics in relation to fatty acid profile were investigated in burned rats receiving total parenteral nutrition (TPN). A fat emulsion of a structured symmetrical triacylglycerol containing only eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (2:1) was prepared. Sprague-Dawley rats were fed by fat-free chow for 2 wk. Then rats were fed exclusively with one of three types of TPN for 7 d. Animals in group C received fat-free TPN (n = 11). Group omega 6 received safflower oil fat emulsion, which accounted for 20% of total caloric intake (n = 11). Group omega 3 received fat emulsion containing only EPA and DHA (1% of total calories, n = 11), in addition to safflower oil emulsion (19% of total calories). On day 5, each rat was subjected to 20% full-thickness scald burns. Rats were sacrificed under ether anesthesia 48 h after burning. The rats in group C became deficient in omega-6 essential fatty acids. Cumulative nitrogen balance was decreased significantly in group omega 6. The rates of whole-body protein synthesis were increased significantly in both groups omega 6 and omega 3. In omega 6, however, the rates of whole-body protein breakdown were increased significantly. In conclusion, the rates of whole-body protein breakdown increased and nitrogen retention was aggravated significantly in animals administered the safflower oil emulsion. Significant increases of urinary excretion of total catecholamine were also observed. Prostaglandin E2 and thromboxane B2 concentrations were not significantly different among three groups. Supplementation with the new omega-3 fat emulsion, however, improved protein metabolism in burned rats receiving TPN.
OBJECTIVE: To investigate the effects of soybean oil emulsion and oral or enteral administration of eicosapentaenoic acid (EPA) on stress response, cytokine production, protein metabolism, and immune function after surgery for esophageal cancer. SUMMARY BACKGROUND DATA: It has been reported that safflower oil, rich in n-6 polyunsaturated fatty acid (n-6 PUFA), affects the survival rate of septic animals and decreases the immune function. It has also been reported that the administration of fish oil, in contrast, reduces these stress responses and stress-induced immunosuppression. In humans, the effects of soybean oil emulsion and the administration of EPA on stress response and immune function after surgery have not been established. METHODS: Patients who underwent esophagectomy with thoracotomy were divided into three groups. Seven patients were fed by total parenteral nutrition (TPN) with soybean oil emulsion, which accounted for 20% of total calories. Seven patients were given oral or enteral administration of 1.8 g/day EPA, in addition to TPN with soybean oil emulsion. Nine patients served as the control group; these patients received fat-free TPN. Serum interleukin-6 (IL-6), C-reactive protein, concanavalin A (con A)- or phytohemagglutinin (PHA)-stimulated lymphocyte proliferation, natural killer cell activity, and stress hormones were measured. RESULTS: The postoperative level of serum IL-6 was significantly higher in the group receiving soybean oil emulsion than in the fat-free group. Oral or enteral supplementation of EPA with soybean oil emulsion significantly reduced the level of serum IL-6 compared with the patients receiving soybean oil emulsion. Con A- or PHA-stimulated lymphocyte proliferation decreased significantly on postoperative day 7 in all groups of patients. The supplementation of EPA with soybean oil emulsion significantly improved the lymphocyte proliferation and natural killer cell activity on postoperative day 21 compared with the group receiving soybean oil emulsion. CONCLUSIONS: Soybean oil emulsion amplifies, and the supplementation of EPA reduces, the stress response and stress-induced immunosuppression.
Pregnancies complicated by placenta praevia and a history of caesarean section are associated with increased risk of placenta percreta (1). Placenta praevia percreta sometimes involves the bladder or other pelvic organ, invasion leading to genital bleeding or haematuria (2, 3). Bladder injury or uncontrollable profuse haemorrhage occasionally occurs in such patients during surgery. Examination of placental invasion is necessary as this clinical condition is severe. Treatment of placental myometrium invasion is required to prevent uncontrollable profuse haemorrhage during surgery. We present a multiparous patient who was diagnosed prenatally with placenta praevia percreta using magnetic resonance imaging (MRI) and who was treated conservatively with a good prognosis.
A decrease in amniotic fluid in prolonged pregnancy is associated with increased fetal morbidity. However, few investigations have been reported on the prediction of this condition. Fetal renal arterial pulsatility index (PI), hourly fetal urine production rate (HFUPR) and amniotic fluid index (AFI) at 39 weeks were studied in 51 singleton pregnancies with (n = 14) and without oligohydramnios (AFI < 5, n = 37) in prolonged pregnancy. There was no difference in the average fetal renal arterial PI and HFUPR between the oligohydramnios group and the normal group. However, the average AFI in the oligohydramnios group was 7.5 +/- 0.9, which was lower than that in the normal group (p < 0.05). We speculated that AFI value at 39 weeks is useful for predicting the incidence of oligohydramnios in prolonged pregnancy.
The aim of this study was to compare the fetal middle cerebral artery (MCA) Doppler waveforms in growth-retarded twin fetuses with (n = 11) and without (n = 24) twin-twin transfusion syndrome (TTTS). Umbilical artery (UA) and fetal MCA Doppler velocity waveforms were recorded on admission. The mean values of the UA pulsatility index (PI) of smaller twin fetuses with and without TTTS were significantly higher than those of normal singleton pregnancies. The mean values of the MCA PI of smaller twin fetuses in the TTTS group (+0.7 +/- 1 SD) were significantly higher than those of normal singleton pregnancies on admission, and these levels did not markedly change following amniocentesis. On the other hand, the values of the MCA of the growth-retarded fetuses without TTTS (-0.9 +/- 1 SD) were significantly lower than those of normal singleton pregnancies. Our findings suggest that measurement of fetal MCA PI is a useful method to assess growth-retarded fetuses in monochorionic twin pregnancies.
The diagnosis of brain death by Doppler ultrasonography and magnetic resonance imaging is reported in a fetus at 23 weeks' gestation. This is believed to be the first instance in which brain death has been shown in a premature fetus with a brain-stem anomaly.
The viscosity behavior of suspensions flocculated by bridging was examined as a function of adsorption affinity of polymers for the particle surface. The polymer chains having strong affinity form fragile bridges between particles as a result of irreversible adsorption. Because the flocs are broken down on the application of shear fields, the flow is shear-thinning. The decrease in the adsorption affinity by the addition of small amounts of surfactant causes the reversible adsorption. The suspensions flocculated by reversible bridging are Newtonian at low shear rates because the polymer bridges are forming and breaking in a quiescent state. When the coil size is comparable to the particle diameter, the suspensions show shear-thickening flow in high shear fields. The shear thickening is induced by the elastic effects of extended bridges. The flow profiles of suspensions flocculated by polymer bridging are controlled by changing the adsorption affinity of polymers. Copyright 1998 Academic Press.
OBJECTIVE: The aim of this study was to evaluate the relationship between febrile response to fetal endotoxin administration and fetal plasma endogenous pyrogen, tumor necrosis factor-alpha, the possible putative pyrogen mediator prostaglandin E2, and the endogenous antipyretic arginine vasopressin in late-gestation pregnant goats. STUDY DESIGN: Changes in fetal core temperature, plasma tumor necrosis factor-alpha, prostaglandin E2, and arginine vasopressin levels were measured after administration of Escherichia coli endotoxin (70 microg/kg of fetal weight) to 10 fetal goats in late gestation. RESULTS: Fetal body temperature did not rise after endotoxin administration. Fetal plasma tumor necrosis factor-alpha and arginine vasopressin increased to 87.5 +/- 15.2 pg/mL and 25.1 +/- 4.8 pg/mL, respectively, after 1 to 2 hours (P < .05). Fetal plasma prostaglandin E2 levels did not change significantly throughout the study. CONCLUSION: The absence of a febrile response to endotoxin in late-gestation fetal goats is accompanied by a deficient responses in prostaglandin generation in the periphery and increased activity of the antipyrogen arginine vasopressin.
> Objective: The purpose of this study was to determine the type of nitric oxide synthase isoform and to measure the quantities of nitric oxide synthase mRNA in the human placenta. Methods: The isoforms of nitric oxide synthase were determined in ten placentas of normal pregnant women using information regarding calcium dependence and inhibition by arginine analogs and findings from Western blot analyses and reverse transcriptase-polymerase chain reaction. Results: The activity of nitric oxide synthase was largely calcium dependent, although a small element of calcium-independent activity was observed. A stronger inhibition was shown with Nomega-nitro-l-arginine than with Nomega-monomethyl-l-arginine. On Western blots endothelial nitric oxide synthase was detected as a band of 140 kilodaltons, without evidence of inducible nitric oxide synthase. Messenger RNA of endothelial nitric oxide synthase was readily detected by reverse transcriptase-polymerase chain reaction, but that of inducible nitric oxide synthase was barely detected. The quantity of mRNA of inducible nitric oxide synthase was about 100-fold less than that of endothelial nitric oxide synthase. Conclusions: These results point to the constitutive endothelial type as the predominant isoform of nitric oxide synthase in human placenta from 37 to 41 weeks gestation, although protein and mRNA of inducible nitric oxide synthase may exist.
For electrorheological (ER) suspensions, the aggregate structures of particles were observed in electric fields by the use of transparent cells with different electrode patterns. Although the suspension is dispersed to noninteracting particles without electric fields, many aggregates are formed on the electrode surface in electric fields. Since the dipole-dipole interactions cause chain structures of particles and equilibrium conformations of chains are always aligned with electric field, the aggregates indicate the presence of columns spanning the electrode gap. The particle concentration in columns which are developed between parallel-plate electrodes is about 22 vol %. In striped electrodes, the particles construct striped aggregates along the electrodes and no particles remain in the insulating region. The particle concentration in striped aggregates is about 35 vol %. The nonuniformity of electric field is responsible for the high particle concentration. The increase in particle concentration of column lead to the high yield stress of electrified suspension. Therefore, the ER performance of suspension as an overall response can be improved by the electrode design.
The purpose of this study was to investigate the effect of insulin-like growth factor-1 (IGF-1) on the translocation of endotoxin from the gut of burned rats. Twenty-eight male Sprague-Dawley rats (7-wk-old) were subjected to 20% full-thickness scald burns and were divided into two groups. One group received 4 mg.kg-1.d-1 of IGF-1 (IGF-1 group, n = 14), and the other received saline (control group, n = 13). All rats were fed exclusively by total parenteral nutrition (TPN). On the second postburn day, rats were killed. The amount of endotoxin in the liver and spleen were measured. RNA from the terminal ileum was extracted, and Northern blot analyses of alpha-tubulin, beta-actin, cell division cycle-2 (cdc2), and immunoglobulin-A (IgA) were performed. Nitrogen balance was improved (p < 0.001), and the wet weight of intestine and its mucosa were increased significantly in the burned rats that received IGF-1. Gene expression of alpha-tubulin and beta-actin were not changed. Cdc2 was elevated (P < 0.05), but IgA was decreased (P < 0.05) in the IGF-1 group. Levels of endotoxin in the liver and spleen were significantly reduced (P<0.05) by the administration of IGF-1. A negative correlation between the levels of endotoxin in the liver and the weight of the intestinal mucosa was observed. In conclusion, IGF-1 improved nitrogen balance, promoted the proliferation of intestinal mucosa and reduced the translocation of endotoxin.
Hypoxanthine is one of the purine nucleotides and is presumed to accumulate during hypoxia and acidemia. It remains uncertain, however, whether plasma hypoxanthine concentration is a useful indicator of fetal asphyxia; and its relationship to other markers of fetal physiologic state is not clearly defined. The aim of this study was to evaluate whether the level of fetal plasma hypoxanthine is correlated with fetal hypoxia and acidosis in growth-retarded fetuses before the onset of labor. Cordocentesis was performed in 34 growth-retarded fetuses at 31-35 weeks' gestation for the measurement of umbilical venous plasma concentrations of hypoxanthine, hemoglobin and lactate concentrations, blood gases, and base deficit. Umbilical venous plasma hypoxanthine concentration was found to be increased significantly, in parallel with the degree of acidosis (r = -0.74, P < 0.05) and base deficit (r = -0.41, P < 0.05), but not to bear a significant relationship to the degree of hypoxemia or other measured variables. We conclude that increases in the plasma concentration of hypoxanthine may reflect an impaired physiological state in growth-retarded fetuses before labor.