[Effects of hypoxemia and umbilical cord occlusion on fetal circulation in sheep].
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Animals↗
Biomedical subjects
S Kozuma
Publications and source records attributed to S Kozuma.
Transvaginal sonographic appearance of hemorrhagic functional ovarian cysts and their spontaneous regression.
OBJECTIVES: To obtain information on the characteristic feature of transvaginal sonograms of hemorrhagic functional ovarian cysts (HFOCs) and their natural course. METHODS: Thirty-four cases of suspected HFOC based on our tentative criteria were ultrasonically followed-up for 3 months. After the study period, the sonographic findings and their changes with time were analyzed. RESULTS: Twenty-four cases were clinically diagnosed as HFOCs, as the masses disappeared naturally. At the first examination, 5 cases (20.8%) showed a diffuse echogenic pattern which seems to consist of a blood clot, 9 (37.5%) were mixed pattern with a clearly demarcated solid part, 3 (12.5%) were hyperechoic sponge-like reticular pattern and 7 (29.2%) were cysts including vague echo inside which looked cotton-like. Seven masses (29.2%) disappeared within 2 weeks and the remaining had a different sonographic appearance with time until they disappeared finally within 8 weeks. CONCLUSIONS: HFOCs show the characteristic changes in transvaginal sonographic appearance and can be diagnosed by short-term follow-up.
Female↗
Development of an artificial placenta: survival of isolated goat fetuses for three weeks with umbilical arteriovenous extracorporeal membrane oxygenation.
The purpose of our study was to examine the feasibility of long-term extrauterine incubation of an isolated premature fetus in artificial amniotic fluid with arteriovenous extracorporeal circulation. Two premature goat fetuses (age 120 and 128 days) were incubated in an isothermal artificial amniotic fluid incubator with arteriovenous extracorporeal membrane oxygenation via the umbilical vessels. We administered pancuronium bromide to suppress fetal movement and swallowing because movement and swallowing have been implicated in fetal deterioration during extrauterine fetal incubation. The fetuses maintained stable circulatory and respiratory parameters. The total incubation time was 494 and 543 h. The animals were then removed from the incubator and stimulated to initiate lung respiration. With ventilator support, both animals maintained stable blood-gas exchange and survived for more than 1 week. These results clearly indicate that umbilical arteriovenous extracorporeal membrane can effectively support extended extrauterine incubation of an isolated premature fetus.
Amniotic Fluid↗
[Assessment of ovarian tumors by transvaginal scanning and clinical significance of ultrasonic examination in postoperative follow up].
A hundred and sixty cases of ovarian tumor were preoperatively examined by transvaginal (TV) and Transabdominal (TA) scanning and accuracy of the assessment for histologic type was compared. We also examined 56 cases of postoperative ovarian cancer by ultrasonography to detect recurrent lesions. Positive predictive values for serous cysts and endometrial cysts were higher with TV than TA. Sensitivity for cancer was also high, but false negative rate was lower with TV than TA. The results showed that scatter from small particles and small mural echo in the cystic mass are visualized more clearly with TV, so that TV is more useful for assessing histological type of ovarian tumors. Sensitivity and specificity of ultrasonographic examination for detecting intraperitoneal recurrent lesions were 88.2% and 97.4%, respectively. Those for extraperitoneal lesions were 86.7% and 97.6%. Ultrasonography is suggested to be useful for detecting recurrence ovarian cancer especially for experitoneal lesions, as laparoscopy is not effective for such lesions.
Female↗
Maturational sequence of fetal breathing movements.
The inspiratory times of fetal breathing movements were measured in REM and NREM periods, respectively, and their changes with advancing gestational age were investigated. Ten women without complications in their 20th to 40th week of pregnancy were examined. Fetal breathing movements and REM were observed simultaneously using ultrasonography. REM and NREM periods were selected for analyzing breathing movements separate from the whole examination period. The inspiratory times of fetal breathing movements were measured with the hand-held pressure transducer. The changes in inspiratory time with fetal age showed the same pattern both in REM and NREM periods. There were no significant changes in inspiratory time before 28 weeks gestational age. After that, the inspiratory time lengthened, showing the maximum at 32-35 weeks and then shortened at 36-40 weeks gestational age. There were no differences of the inspiratory time between REM and NREM periods before 32 weeks. After 32 weeks, the inspiratory time in the NREM period was longer than in the REM period. These changes in fetal breathing movements are thought to be caused by the morphological maturation of the fetal lung and the functional development of respiratory and sleep center of the fetal central nervous system.
Embryonic and Fetal Development↗
[Developmental sequence of fetal behavior and the functional development of the fetal central nervous system].
The development of central nervous system (CNS) is the latest among the various fetal organs and is on the way to mature even at birth. Because behavior is the phenotype of the CNS function, the behavioral pattern significantly changes with the developmental stage of CNS throughout the whole fetal period. The purpose of this study is to clarify the developmental sequence of fetal behavior and to discuss the functional development of the fetal CNS. For the first step of this study, thirty-one normal pregnant women, between 20 and 41 weeks of gestation, were examined for 60 minutes by using four ultrasonographic machines, which were employed simultaneously for observing four parts of each fetus: head, trunk, upper and lower extremities. All fetal movements were categorized according to the moving parts of the body and the peculiarities of movement. Trunk movements include six types i.e. flexion, stretch, rolling, startle, jumping (stepping), and writhing. The peak incidences of flexion and stretch were in 28-31 weeks of gestation. The incidence of rolling movements was high in 24-27 weeks, thereafter lowered gradually with gestational age, and then showed the significant increase in 40-41 weeks. The incidences of startle and jumping movements were high before 28 weeks, and then decreased significantly. Writhing movements were often observed after 28 weeks. The other movements showed the respective patterns of the changes in the incidence. Secondly, animal experiments were performed to obtain the basic data on fetal behavior which could not be given by the ultrasonographic observation of human fetuses. Fetal goats were incubated under the physiological condition in artificial amniotic fluid by using extracorporeal membrane oxygenation (ECMO) system.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Development of artificial placenta: oxygen metabolism of isolated goat fetuses with umbilical arteriovenous extracorporeal membrane oxygenation.
To assess the oxygen utilization of extrauterine goat fetuses with arteriovenous extracorporeal membrane oxygenation via umbilical vessels, oxygen delivery (OD) and oxygen consumption (OC) were investigated in 19 long-term incubations (incubation periods 58-236 h). The OCs did not change (6.4 +/- 1.3 ml/min/kg, mean +/- SD, n = 227) when the ODs were more than 10 ml/min/kg, but were significantly suppressed when the ODs were less than 10 ml/min/kg. It was suggested that the oxygen metabolism of extrauterine goat fetuses is equivalent to that of fetuses in utero.
Animals↗
Artificial placenta: long-term extrauterine incubation of isolated goat fetuses.
Previously, this group reported on a system of extrauterine incubation of a goat fetus, in which the fetus is surrounded by artificial amniotic fluid and connected to the circuit with an ECMO (extracorporeal membrane oxygenator) by the umbilical arteries and veins. The following is a summary of recent progress using an improved method of catheterization and a new system that included a dialyzer within the circuit. Nine goat fetuses were used in this experiment. Six goats were successfully incubated; the duration of their incubation was 146.5 +/- 61.3 h (mean +/- SD). The longest one was 236 h. Slowly progressive circulatory depression was thought to be the main cause of fetal death. Marked tendencies to bleeding and water retention were not observed in any cases. Stable serum electrolyte levels were maintained.
Animals↗
Development of extrauterine fetal incubation system using extracorporeal membrane oxygenator.
Despite the recent progress in perinatal medicine, it is still difficult to manage the extremely immature newborn. A new extrauterine incubation system has been developed using 14 goat fetuses. The goat fetus is surrounded by artificial amniotic fluid and is connected to an extracorporeal membrane oxygenator. The blood is drained from the umbilical arteries and returned to the umbilical vein. The perfused blood is recirculated and ventilated with a mixture of O2, N2, and CO2 gases to obtain a PO2 of 30-35 mm Hg and a PCO2 of 30-35 mm Hg in the umbilical venous blood. Fetal heart rate, blood pressure, electroencephalogram, and several movement parameters are continuously recorded by the polygraph. With this system, the fetuses can be kept under fairly stable physiological conditions for periods up to 165 h. This improved system might therefore become a useful method to manage the ill fetuses and newborns.
Animals↗
Ultrasonic evaluation and classification of ovarian tumors.
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Female↗
Neuro-Behcet's disease showing severe atrophy of the cerebrum.
A 38-year-old female died 6 years after the onset of what was, clinically and histopathologically, consistent with neuro-Behcet's disease. Pathologically the cerebrum showed severe atrophy. The main changes were observed in the grey and white matter, the diencephalon and the basal ganglia by light microscopy. All these changes originated in softenings around blood vessels, especially small vessels or capillaries. These foci fused together to form large regions of softening. Glial or mesenchymal reactions were minimal. In the white matter there was slight perivascular-infiltration, mainly consisting of lymphocytes. In view of these findings, it is suggested that these changes were caused by an allergic vasculitis. The present case of Neuro-Behcet's disease is the first one showing general atrophy of the cerebrum. It is very important in relation to demyelinating encephalitis.
Adult↗
A study on the development of sleep-wakefulness cycle in the human fetus.
We observed fetal behavior by using three ultrasonic real-time scanners simultaneously in 30 normal pregnant women between 20 and 40 weeks of gestation and analyzed developmental changes in behavioral pattern focussing the attention on the characteristics of REM and non-REM sleep and wakeful state. The frequency of REM significantly increased with gestational age, and its occurrences formed a group in late pregnancy. REM and non-REM periods, which were defined as the phase with uninterrupted appearance of rapid eye movements and the phase without them over 3 min, respectively, became clearly distinguishable between 28 and 31 weeks of gestation. The correlation between the occurrence of rapid eye movements and breathing movements was high after 27 weeks. These results demonstrate the course of the development of sleep-wakefulness cycle in the human fetus.
Behavior↗
A primary cell culture system for human cytotrophoblasts of proximal cytotrophoblast cell columns enabling in vitro acquisition of the extra-villous phenotype.
Cytotrophoblast (CT) differentiation into the extra-villous phenotype is a crucial process in initiating their invasion into the decidua and thereby developing the placenta. However, how CTs differentiate into extra-villous CTs (EVCTs) is not fully elucidated. To address this, a suitable culture model for CTs has been long-sought. But this has been hampered by annoying problems such as; cell aggregation, in vitro syncytialization, low plating efficiency, etc. The aim of this study is to develop a culture system in which CTs differentiate into EVCTs. CTs were isolated from the first trimester placenta using density gradient separation and immuno-depletion using anti-CD9 antibody to remove contaminating fibroblasts and EVCTs. The resultant isolated CTs were found to have the character similar to poorly differentiated CTs comprising proximal cytotrophoblastic cell columns as confirmed by immunocytochemical and flowcytometric analyses. When cultured on type 4 collagen-coated plates in culture media containing low calcium concentration, CTs neither aggregated nor syncytialized, remaining mononuclear and monolayer state. Interestingly, cultured CTs gradually upregulated integrin alpha1, CD9, and human leukocyte antigen (HLA)-G; the known markers specific for EVCTs invading into the decidua diffusely. Hence, the CT culture system provides a sophisticated experimental model in which highly purified CTs acquire the extra-villous phenotype without syncytialization.
Adult↗
Evidence for basic fibroblast growth factor as a crucial angiogenic growth factor, released from human trophoblasts during early gestation.
The objective of this study was to clarify the possible angiogenesis-promoting factors from human trophoblasts in early stage gestation. The existence of angiogenic growth factors such as basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) in the condition medium from human villous trophoblasts was determined. Biological activity of angiogenic growth factors released by trophoblasts was examined using vascular endothelial cell lines. The condition medium from trophoblasts enhanced the growth of endothelial cells. Although cultured trophoblasts exhibited immunoreactive products for both bFGF and VEGF in the cytoplasm, only bFGF was detected in the condition medium by ELISA. The growth-enhancing activity of the condition medium was eliminated completely by the addition of anti-bFGF antibody but not with anti-VEGF antibody. Thus, trophoblastic cells seem to play an important role in extensive angiogenesis occurring in early gestation, mainly by releasing bFGF but not VEGF.
Adult↗
A fetus with Prader-Willi syndrome showing normal diurnal rhythm and abnormal ultradian rhythm on heart rate monitoring.
Clinical features of Prader-Willi syndrome in neonates are marked hypotonia with the absence of crying and feeding difficulty so that prenatal diagnosis of Prader-Willi syndrome is strongly hoped in order to provide appropriate medical and psychological care for neonates and their families. However, the clinical picture of Prader-Willi syndrome in utero has not been well described. We report a pregnancy associated with Prader-Willi syndrome manifesting polyhydramnios, large biparietal diameter of the fetus and characteristic fetal heart rate pattern: prolonged inactive periods and diurnal variation of the incidence of heart rate accelerations. These findings may offer a clue to the prenatal diagnosis of Prader-Willi syndrome, although molecular cytogenetics is mandatory for the definite diagnosis.
Activity Cycles↗