Rintaro Sawa

The relationship between uterine artery Doppler velocimetry and umbilical venous adenosine levels in pregnancies complicated by preeclampsia

OBJECTIVE The aim of this study was to evaluate the relationship between uteroplacental circulatory insufficiency and the fetoplacental release of adenosine in pregnancies complicated by preeclampsia. STUDY DESIGN We performed uterine artery Doppler velocimetry and calculated the pulsatility index of the uterine artery, to detect uteroplacental circulatory insufficiency, immediately before cordocentesis in 39 pregnant women complicated by preeclampsia. Umbilical venous blood obtained by cordocentesis was then analyzed for blood gases, pH, and plasma adenosine levels. Increased plasma adenosine was taken to signal its increased release from the placenta and fetus relative to its rate of disappearance. RESULTS The mean umbilical venous plasma adenosine level in the abnormal pulsatility index group was 1.78 +/- 0.17 mumol/L (mean +/- SEM, n = 25), significantly higher than in the normal pulsatility index group 0.58 +/- 0.14 mumol/L (n = 14, p < 0.001). Furthermore, in the abnormal pulsatility index group the elevation of plasma adenosine levels in the umbilical vein was found even in normoxic fetuses. CONCLUSION Fetal plasma adenosine increases before uteroplacental circulatory insufficiency becomes severe enough to cause generalized fetal hypoxemia. We postulate that enhanced adenosine formation in the fetus, umbilical cord vessels, and particularly the placenta may, at least in part, contribute to control and maintenance of placental blood flow.

Clinical Trial of Induction of Labor versus Expectant Management in Twin Pregnancy

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 E2 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.

Plasma Adenosine levels and P-selectin expression on platelets in preeclampsia

Objective To measure the correlation of plasma adenosine levels with platelet activation in women with preeclampsia. Methods Plasma adenosine concentration and expression of P-selectin, a marker for platelet activation, were measured in 18 normal pregnant women and 18 preeclamptic women. The effect of 8-sulfophenyltheophylline, an adenosine receptor blocker, on expression of P-selectin on platelets also was measured. Results Plasma adenosine level averaged 0.77 ± 0.11 μM (standard error of the mean [SEM]) in women with preeclampsia, significantly higher than the mean level of 0.47 ± 0.08 μM in women with normal pregnancies (P < .05). Expression of P-selectin on platelets averaged 7.8 ± 1.2% in women with preeclampsia, also significantly higher than the mean level of 4.7 ± 0.7% in normal pregnancy (P < .05). Adenosine receptor blockade significantly increased expression of P-selectin on platelets in women with preeclampsia by 26% (P < .05), which was significantly higher than the 13% increase of activation in those with normal pregnancies (P < .05). Conclusion Adenosine is an established platelet activation suppressor. Increased plasma levels of adenosine in preeclampsia might partially compensate and tend to prevent further excessive platelet activation in women with preeclampsia.

Relation between adenosine and T-helper 1/T-helper 2 imbalance in women with preeclampsia

OBJECTIVE To evaluate the relationship between changes in plasma adenosine concentration and imbalances in the T‐helper 1/T‐helper 2 ratio in peripheral blood of women with preeclampsia. METHODS Plasma adenosine concentrations and the T‐helper 1/T‐helper 2 ratio were examined in the peripheral blood of 16 preeclamptic and normal pregnant women. The proportion of specific T‐cell marker CD4‐positive cells expressing intracellular cytokines, interferon‐γ derived from T‐helper 1 and interleukin‐4 derived from T‐helper 2 cells, were analyzed by flow cytometry. The ratio of interferon‐γ secreting cells to interleukin‐4 secreting cells was taken as the T‐helper 1/T‐helper 2 ratio in vivo. The effect of the adenosine‐receptor blocker 8‐sulfophenyltheophyl‐line was also measured in vitro. RESULTS Mean plasma adenosine concentration in preeclampsia was significantly higher than that in normal pregnancy (0.68 ± 0.07 μmol/L versus 0.39 ± 0.06 μmol/L, P < .05). The proportions of interferon‐γ secreting cells increased and interleukin‐4 secreting cells decreased significantly in preeclampsia, and the T‐helper 1/T‐helper 2 ratio in preeclampsia was significantly higher than in normal pregnancy (18.1 ± 2.6 versus 9.9 ± 1.5, P < .05). The increase of the proportion of interferon‐γ secreting cells after adenosine receptor blockade in preeclampsia significantly exceeded that of normal pregnancy. The T‐helper 1/T‐helper 2 ratio in preeclampsia was significantly greater than that in normal pregnancy (36% versus 17%, P < .05). CONCLUSION Increased plasma adenosine may be involved in the regulation of imbalances in the T‐helper 1/T‐helper 2 ratio in women with preeclampsia.

Increased plasma adenosine concentrations and the severity of preeclampsia

OBJECTIVE To investigate the relationship between changes in plasma adenosine and the severity of preeclampsia, and norepinephrine and tumor necrosis factor–α concentrations. METHODS Plasma concentrations of adenosine, norepinephrine, and tumor necrosis factor–α relating to the pathogenesis of preeclampsia were measured in women with mild (n = 21) and severe (n = 21) preeclampsia and normal pregnancies (n = 21), matched for age, gestational age, and parity, in the third trimester of pregnancy. We then evaluated the relationships among plasma adenosine, norepinephrine, tumor necrosis factor–α concentrations, and the severity of preeclampsia. RESULTS Mean plasma adenosine, norepinephrine, and tumor necrosis factor–α concentrations were significantly higher in women with mild and severe preeclampsia than in normal control subjects (P < .05). In women with preeclampsia, plasma adenosine concentrations increased according to the severity of preeclampsia (0.60 ± 0.03 μmol/L and 0.72 ± 0.03 μmol/L, respectively, versus 0.41 ± 0.03 μmol/L for normal subjects), which correlated with increases of norepinephrine and tumor necrosis factor–α concentrations (r = .58, P < .05; r = .49, P < .05, respectively). In preeclampsia, norepinephrine concentration also correlated with maternal blood pressure (r = .50, P < .05). CONCLUSION Adenosine is an established suppressor of the effects of norepinephrine and tumor necrosis factor–α The increased plasma concentrations of adenosine in preeclampsia might serve to counteract further progression of the complication.

Preoperative diagnosis of dehiscence of the lower uterine segment in patients with a single previous Caesarean section

Summary: Preoperative diagnoses were checked during surgery in 39 patients who underwent elective repeat Caesarean section with (n = 20) and without (as control, n = 19) a preoperative diagnosis of wall dehiscence (thinning) of the lower uterine segment (LUS). All patients were examined manually and by ultrasonography at 36 weeks gestation before labour. A preoperative diagnosis of wall dehiscence was made when the wall thickness was less than 2 mm and/or the patient felt pain and tenderness in the LUS. Surgical findings of dehiscence were j defined as a subperitoneal separation of the uterine I scar in the LUS. The sensitivity and specificity of our ultrasonographic evaluations were found to be 100% and 83% (p < 0.05), respectively. On the other hand, there were no surgical findings of dehiscence in patients who felt pain and tenderness in the LUS with a wall thickness greater than 2 mm, nor among those in the control group.

Iatrogenic monoamniotic twin gestation with progressive twin-twin transfusion syndrome.

Objective: Intentional puncture of the membrane has been reported to be a promising new method for the management of twin-twin transfusion syndrome. Case Report: Treatment of twin-twin transfusion syndrome with serial amniocenteses resulted in unintentional puncture of the dividing membrane at 24 weeks of gestation. Fetal growth discordance increased, and twin-twin transfusion did not improve following the puncture. Intrauterine death of both fetuses at 27 weeks of gestation occurred. Conclusion: Amniotic septostomy for the treatment of twin-twin transfusion sydnrome should be performed with serious consideration.

Serum adenosine deaminase activity in women with hyperemesis gravidarum.

BACKGROUND Serum adenosine deaminase (ADA) activity increases in diseases where cellular immunity is stimulated. Since hyperemesis gravidarum is characterized by enhanced cell-mediated immunity, serum ADA activity may be altered. The present study evaluated the relation between serum ADA activity and changes in cell-mediated immunity as causes of changes in ADA activity in hyperemesis gravidarum. METHODS Serum activities of total ADA and its isoenzymes, ADA1 and ADA2, were measured in women with hyperemesis gravidarum (n = 24) and normal pregnancies (n = 24). Peripheral blood lymphocyte and monocyte counts were also measured. RESULTS In hyperemesis gravidarum, serum total ADA and ADA2 activities averaged 16.8 +/- 0.5 and 13.3 +/- 0.7 U/l, respectively, which were significantly higher than those in normal pregnancies (10.2 +/- 0.5 and 7.8 +/- 0.5 U/l, respectively) (p < 0.05). The mean values for ADA1 activity in women with hyperemesis gravidarum and normal pregnancies were similar. The increase in total ADA activity was accompanied by the increase in lymphocyte and monocyte counts. CONCLUSIONS These results suggest that increased serum total ADA activity reflects increases in ADA2 activity, which may be at least in part attributed to enhanced cell-mediated immunity in hyperemesis gravidarum.

Relation between adenosine deaminase activities and cytokine-producing T cells in women with preeclampsia

OBJECTIVES To investigate the relation between plasma adenosine deaminase (ADA) activity and cytokine-producing T cells in preeclampsia. DESIGN AND METHODS Plasma ADA activity and the proportions of cytokine-producing T cells were measured in peripheral blood of 28 women with normal pregnancies and preeclampsia. The proportion of CD4-positive T cells producing interferon-gamma and interleukin-4 were analyzed by flow cytometry. RESULTS Plasma ADA activity in preeclampsia was significantly higher than that in normal pregnancy (p < 0.05). In preeclampsia, the proportion of interferon-gamma producing cells significantly increased, and the proportion of interleukin-4 producing cells was significantly decreased compared with normal pregnancy. A significant correlation was found between ADA activity and the proportion of interferon-gamma producing cells in preeclampsia (r = 0.58, p < 0.05). CONCLUSIONS Increased plasma ADA activity in preeclampsia may be in part associated with changes in the proportion of interferon-gamma secreting cells.

Sonographic evaluation of umbilical cord insertion with umbilical coiling index.

The aim of this study was to investigate the association between umbilical cord hypocoiling and abnormal placental insertion of the umbilical cord.