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Hiroshi Chisaka

Publications and source records attributed to Hiroshi Chisaka.

12 recordsLinked to original sources
PubMed2006

Fetal myocardial thickening measured by ultrasonic-based technique called 'phased-tracking method'.

OBJECTIVE: To evaluate fetal myocardial movement by using newly developed ultrasonic technique. METHODS: We analyzed 50 normal fetuses between 25 and 41 weeks' gestation for changes in thickness of fetal myocardium using the phased-tracking method, a technique with high vertical distance resolution and the potential to evaluate fine ventricular wall movements. We analyzed differences in the rate of change in ventricular wall thickness and in changes in the inner and outer wall layers with advancing gestation. We also analyzed myocardial thickening period and evaluated the ratio of increasing thickness period to stroke interval. RESULTS: Mean thickness changing rate was significantly higher in the right (1.18 +/- 0.34 m/s/m) than in the left ventricular wall (0.86 +/-0.31 m/s/m) (p < 0.001). Mean ratio of increasing thickness period to stroke interval was significantly higher in the right (0.57 +/- 0.064) than in the left ventricle (0.46 +/- 0.075) (p < 0.001), indicating that myocardial contraction in the fetal right ventricle predominates. The thickness-changing rate of the bilateral ventricular walls was positively and linearly correlated with gestational age. The myocardial-wall thickness-changing rate was higher in the outer layer than in the inner layer in late gestation. CONCLUSIONS: We conclude that measurement of the thickness-changing rate of fetal ventricular walls using the phased-tracking method might be useful for evaluation of fetal cardiac function.

Echocardiography↗
PubMed2006

Appearance of abnormal electrocorticogram patterns during umbilical cord compression in sheep fetus.

A frequent cause of fetal acidemia, which sometimes results in hypoxic-ischemic encephalopathy, is umbilical cord compression associated with uterine contraction. Using a sheep model of fetal acidemia, we examined the changes in electrocorticogram (ECoG), carotid artery blood flow, arterial blood pressure and fetal heart rate during cord compression. A characteristic burst of ECoG spikes emerged during cord compression at fetal arterial pH 7.18 even before the pH went down to severe fetal acidemia (less than 7.10). The administration of a neuromuscular blocking agent to the fetus did not abolish the appearance of the spikes. These results suggest that cord compression may cause abnormal brain excitement even in the absence of severe fetal acidemia and that this abnormal excitement can lead to fetal brain dysfunction, if cord compression is repeated or prolonged.

Acidosis↗
PubMed2006

Clinical manifestations and outcomes of parvovirus B19 infection during pregnancy in Japan.

Parvovirus B19 is a small DNA virus. Infection with parvovirus B19 during pregnancy may cause serious complications in the fetus, including hydrops fetalis and fetal death. The purpose of the present study is to clarify the clinical manifestations and outcomes of parvovirus B19 infection during pregnancy. This prospective study enrolled 478 women with suspected B19 infections during pregnancy between 1999 and 2004. One hundred cases (21%) of B19 infection were detected in 478 pregnant women who had been exposed to B19. Serological infection was confirmed by measurement of B19-specific IgM and IgG in sera. Forty-nine cases reported maternal clinical symptoms and 51 cases were asymptomatic. Facial rash was the most common symptom, with 51% (25/49) of the symptomatic patients complaining of either a facial, body or limb rash. The most common infectious source was children living in the home. Overall, the incidence of adverse fetal effects (including hydrops fetalis and fetal death) related to intrauterine B19 infection was 7% (7/100), and all seven cases were exposed to B19 infection before 20 weeks of gestation. Although half of the cases with parvovirus B19 infections during pregnancy were asymptomatic, patients with adverse fetal effects tended to be symptomatic including rash and fever. These clinical data may supply useful information to produce clinical guidelines for managing B19 infection during pregnancy.

Abortion, Spontaneous↗
PubMed2005

Decrease and senescence of endothelial progenitor cells in patients with preeclampsia.

BACKGROUND: In preeclampsia, the precise mechanism of impaired vascular function is still unclear. We hypothesized that cellular function of circulating endothelial progenitor cells (EPCs) might be impaired in patients with preeclampsia. OBJECTIVE: The objective of this study was to investigate the number and status of cellular senescence of EPCs in the circulation of women with preeclampsia. METHODS: Circulating EPCs were cultured from patients with preeclampsia (n = 8) and normotensive pregnant women (n = 7). EPC numbers were assessed by colony-forming unit (CFU) methodology as previously reported. In addition, to assess cellular senescence, we measured endogenous beta-galactosidase activity. Moreover, we assessed whether the serum level of C-reactive protein (CRP), a marker for systemic inflammation, was associated with cellular impairment of EPCs. RESULTS: The number of circulating EPCs was decreased in women with preeclampsia controls (median, 10.0 vs. 34.0 CFU; P < 0.01). The rate of cellular senescence was significantly increased in patients with preeclampsia (33.9%) compared with that in controls (22.9%; P < 0.05). Patients with preeclampsia were divided into two subgroups: the CRP-negative group (CRP, <0.1 mg/dl; n = 4) and the CRP-positive group (CRP, > or =0.1 mg/dl; n = 4). Interestingly, EPC CFU counts were markedly decreased in CRP-positive patients compared with those in CRP-negative patients (5.0 and 25.0 CFU, respectively; P < 0.05). Median values for cellular senescence were greater in the CRP-positive group than in the CRP-negative group, although this did not achieve statistical significance (43.5% and 33.3%, respectively; P = 0.12). CONCLUSION: Depletion and cellular aging of EPCs in patients with preeclampsia might be associated with endothelial dysfunction and could be affected by systemic inflammation.

Adult↗
PubMed2005

Effect of pro-inflammatory cytokines on expression and activity of 11beta-hydroxysteroid dehydrogenase type 2 in cultured human term placental trophoblast and human choriocarcinoma JEG-3 cells.

OBJECTIVE: 11Beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) is thought to act as a placental barrier protecting the fetus from high levels of maternal cortisol. On the other hand, intrauterine infection is one of the main causes of preterm birth and adverse fetal outcome, and pro-inflammatory cytokines may contribute to these adverse effects. However, the effect of pro-inflammatory cytokines on 11beta-HSD2 is still not clear. Therefore, we have evaluated the effect of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) on 11beta-HSD2 in cultured human placental trophoblast and in human choriocarcinoma JEG-3 cells. METHODS: Placental trophoblast cells were isolated from human term placenta. Placental trophoblast cells and JEG-3 cells were treated with TNF-alpha (0.1-10 ng/mL) or IL-1beta (0.1-10 ng/mL). Real-time reverse transcription polymerase chain reaction and Western blot were used to study the regulation of 11beta-HSD2 expression. 11beta-HSD2 activity was determined by measuring the rate of cortisol to cortisone conversion in the culture medium using thin-layer chromatography (TLC). RESULTS: In placental trophoblast, TNF-alpha and IL-1beta down-regulated 11beta-HSD2 mRNA expression and activity (both P <.05). The protein level was decreased only with IL-1beta (P <.05). In JEG-3 cells, 11beta-HSD2 mRNA was decreased by TNF-alpha but up-regulated by IL-1beta, with no significant change in protein expression and activity. CONCLUSION: Our results suggest caution in interpreting data using JEG-3 cells. However, our studies with primary trophoblast suggest that TNF-alpha and IL-1beta may increase the amount of cortisol crossing to the placenta and fetal circulation by attenuating 11beta-HSD2 activity, potentially contributing to preterm labor and altered fetal outcome in uterine infection.

11-beta-Hydroxysteroid Dehydrogenase Type 2↗
PubMed2005

Successful conservative treatment of a cesarean scar pregnancy with uterine artery embolization.

Ectopic pregnancy developing in a previous Cesarean section scar is rare and is associated with catastrophic complications, such as uterine rupture and uncontrollable bleeding, which may lead to loss of the uterus. The operative treatments that have been reported for cesarean scar pregnancy are dilatation and curettage and excision of trophoblastic tissues using either laparotomy or laparoscopy. Recently, conservative treatment of scar pregnancy with locally and/or systemically administered methotrexate (MTX) has been reported. However, recent reports demonstrated that cases treated with MTX sometimes required laparotomy later because of excessive bleeding. In this series of cases we have demonstrated that viable cesarean scar pregnancies can be treated safely by selective transarterial embolization in combination with subsequent dilatation and curettage and local or systemic injections of MTX. In these three cases, uterine artery embolization proved to be a useful procedure for preventing uncontrollable bleeding and unnecessary uterine loss.

Abortion, Induced↗
PubMed2003

Fractal and periodic heart rate dynamics in fetal sheep: comparison of conventional and new measures based on fractal analysis.

The physiological significance of spectral and fractal components of spontaneous heart rate (HR) variability in the fetus remains unclear. To examine the relationship between circadian rhythms in different measures of HR variability, R-R interval time series obtained by fetal ECGs were recorded continuously over 24 h in five pregnant sheep at 116-125 days gestation. Conventional measures of short-term (STV) and long-term variability (LTV), low-frequency (LF; 0.025-0.15 cycles/beat) and high-frequency (HF; 0.2-0.5 cycles/beat) spectral powers, the LF-to-HF ratio, and fractal dimension values were calculated from 24-h ECG recordings and quantified every 60 min. STV, LTV, and LF and HF spectral powers were minimal during the day but increased significantly to their highest values at night. We found a significant positive correlation between these measures, whereas the cosinor method showed significant similarity between their circadian rhythm patterns. Fetal R-R intervals also exhibited fractal structures. Fetal HR variability had a fractal structure, which was similar between day and night. These results suggested that the circadian rhythms exhibited by STV and LTV during the day were mainly due to changes in frequency components rather than to fractal components of fetal HR fluctuation.

Animals↗
PubMed2003

Establishment of multifunctional monoclonal antibody to the nonstructural protein, NS1, of human parvovirus B19.

OBJECTIVES: NS1 expression of human parvovirus B19 is a critical event in B19 pathogenesis. However, the mechanisms of NS1-induced cytotoxicity in B19 infection have yet to be clarified mainly because of the absence of multifunctional monoclonal antibodies (Mab) against NS1. The purpose of this study was to establish such Mab, which function in immunoprecipitation assays, immunoblotting, indirect immunofluorescence, and immunohistochemical staining. METHODS: Balb/c mice were immunized with the recombinant NS1 protein and hybridoma cell lines producing Mab against the NS1 protein were screened by ELISA, immunoprecipitation, immunoblotting, and indirect immunofluorescence staining. The Mab were used for immunohistochemical staining of formalin-fixed tissues from an intrauterine B19 infected fetus. RESULTS: ParC-NS1, the monoclonal antibody against the NS1 protein, worked in all tested screening methods. ParC-NS1 could also detect NS1 protein expressed in clinical tissue specimens. CONCLUSIONS: The ParC-Ns1 monoclonal antibody was specific against the NS1 protein. In addition, NS1 protein expression was successfully identified in human tissues. These data indicated that this monoclonal antibody should be a useful tool to study the kinetics and sites of NS1 expression and NS1-induced cytotoxicity in B19 infection.

Animals↗
PubMed2002

A transgenic mouse model for non-immune hydrops fetalis induced by the NS1 gene of human parvovirus B19.

Human parvovirus B19 (B19) infection during pregnancy is associated with the adverse foetal outcome known as non-immune hydrops fetalis (NIHF). Although B19 is known to infect erythroid-lineage cells in vivo as well as in vitro, the mechanism leading to the occurrence of NIHF is not clear. To investigate the possible involvement of the B19 non-structural protein NS1 in NIHF, three independent lines of transgenic mice were generated that expressed NS1 under the control of the Cre-loxP system and the GATA1 promoter. Two of the three lines expressed NS1 in erythroid-lineage cells. Most of the transgenic mice died at the embryonic stage, some of which developed hydropic changes caused by severe anaemia at embryonic day 15.5 (E15.5). Histological examination of embryos at E15.5 showed significantly fewer erythropoietic islands in the liver parenchyma, whereas their hearts showed no abnormal signs, such as cardiomegaly and apoptotic cells. The NS1-transgenic mouse lines established here provide an animal model for human NIHF and suggest that NS1 plays a crucial role in the adverse outcome associated with intrauterine B19 infection in humans.

Animals↗
PubMedDate not supplied

Parvovirus B19 and the pathogenesis of anaemia.

Human parvovirus B19 (B19) infection causes human bone marrow failure, by affecting erythroid-lineage cells which are well-known target cells for B19. The anaemia induced by B19 infection is of minor clinical significance in healthy children and adults, however, it becomes critical in those afflicted with haemolytic diseases. This condition is called transient aplastic crisis, and the pathogenesis is explained by the short life-span of red blood cells. Similarly, fetuses are thought to be severely affected by B19-intrauterine infection in the first and second trimester, as the half-life of red blood cells is apparently shorter than RBC at the bone marrow haematopoietic stage. On the other hand, B19 is also the causative agent of persistent anaemia in immunocompromised patients, transplant recipients and infants. The deficiencies of appropriate immune responses to B19 impair viral elimination in vivo, which results in enlargement of B19-infected erythroid-lineage cells. The B19-associated damage of erythroid lineage cells is due to cytotoxicity mediated by viral proteins. B19-infected erythroid-lineage cells show apoptotic features, which are thought to be induced by the non-structural protein, NS1, of B19. In addition, B19 infection induces cell cycle arrests at the G(1) and G(2) phases. The G(1) arrest is induced by NS1 expression prior to apoptosis induction in B19-infected cells, while the G(2) arrest is induced not only by infectious B19 but also by UV-inactivated B19, which lacks the ability to express NS1. In this review, we address the clinical manifestations and molecular mechanisms for B19-induced anaemia in humans and a mouse model, and of B19-induced cell cycle arrests in erythroid cells.

Adult↗
PubMedDate not supplied

Clinical evaluation of the risk of twin-to-twin transfusion syndrome using the relative power contribution of fetal heart rate fluctuations.

OBJECTIVES: In twin pregnancies, it has been suggested that fluctuations of the two fetal heart rates should be considered as two variates that affect each other. We therefore investigated whether the relative power contribution (RPC) of heart rate fluctuation between twins reflects the clinical severity of twin-to-twin transfusion syndrome. STUDY DESIGN: Sixty-three cases of twin pregnancy including 43 monochorionic twins and 20 dichorionic twins were studied. Thirteen monochorionic twins with polyhydramnios in one twin were regarded as twin-to-twin transfusion syndrome (TTTS). Of the 13 TTTS cases, 8 cases with polyhydramnios in one twin and oligohydramnios in the other were deemed to be a 'stuck' twin. The RPC of the very low frequency domain (VL; 0.0125-0.0625 Hz) of fetal heart rate fluctuation in the twin fetuses of monochorionic and dichorionic pregnancies was obtained within a week of delivery. The relationship between the value of the RPC and the outcome of these twins was examined. RESULTS: For both monochorionic and dichorionic twins the RPC of twin fetuses was significantly higher in TTTS twins than in twins without TTTS. In particular, in pregnancies that resulted in fetal death, early neonatal death, or hydrops of one of the twins, this twin had a higher RPC than the other twin. No significant difference was observed in the RPC value between twins of either monochorionic or dichorionic pregnancies that did not develop TTTS. Serial changes in RPC values were followed in 7 cases of TTTS. The RPC value rose rapidly just before delivery in three cases with resultant poor outcome. CONCLUSION: A rapid change in the RPC of twin fetuses measured using the VL frequency domain of fetal heart rate fluctuations may predict poor outcome in twin pregnancies.

Female↗