Validation of Quintero stage III sub-classification for twin-twin transfusion syndrome based on visibility of donor bladder: characteristic differences in pathophysiology and prognosis.

OBJECTIVE: To validate the Quintero stage III subclassification for twin-twin transfusion syndrome (TTTS) based on visibility of the bladder of the donor twin. METHODS: Between July 2002 and August 2006, there were 131 pregnant Japanese women affected by severe TTTS before 26 weeks' gestation, treated with fetoscopic laser surgery at five centers in Japan, whose pregnancies continued beyond 22 weeks. Outcome data were available in all cases and surviving infants were followed up for at least 6 years. This study focused on the Stage III TTTS patients. These were subclassified into Stage III atypical (abnormal Doppler flow with visible donor bladder) and Stage III classical (abnormal Doppler flow with non-visible donor bladder) groups. Perioperative data and postnatal outcomes were compared between the groups. RESULTS: Seven Stage I, 22 Stage II, 82 Stage III and 20 Stage IV pregnancies continued beyond 22 weeks. There was a significantly higher incidence of absent or reversed end-diastolic velocity in the umbilical artery (UA-AREDV) of the donor in Stage III atypical than in Stage III classical patients (83.8% vs. 53.3%, P = 0.004). Stage III atypical cases also had a significantly higher incidence of arterioarterial (AA) anastomoses (72.9% vs. 17.8%, P < 0.001) and intrauterine fetal demise (IUFD) of the donor (43.2% vs. 13.3%, P = 0.002). However, there were no differences in overall survival or in abnormal brain scans of surviving infants. Donors with both UA-AREDV and AA anastomoses had a significantly higher incidence of IUFD compared with the others (53.3%, P < 0.001). CONCLUSIONS: Quintero stage III atypical was characterized by a high incidence of AA anastomoses and UA-AREDV of the donor, resulting in IUFD. Subclassification of Stage III based on visibility of the bladder of the donor twin was adequate for and compatible with differentiating prognosis and pathophysiology.

In vivo endoscopic assessment of arterioarterial anastomoses: insight into their hemodynamic function.

OBJECTIVE: To assess endoscopically the hemodynamic function of arterioarterial (AA) anastomoses in twin-twin transfusion syndrome (TTTS) and monochorionic selective intrauterine growth restriction (IUGR). MATERIALS AND METHODS: The videotapes of TTTS and IUGR patients undergoing laser surgery between July 1997 and December 2001 were reviewed for the presence of AA anastomoses. The hemodynamic equator was defined as the site within the AA anastomosis with color flashing. AA anastomoses were classified as having unidirectional flow, having bi-directional flow, or being non-functional, depending on whether the hemodynamic equator reached a returning vein to one, both, or neither twin, respectively. TTTS was classified in stages as previously described. RESULTS: AA anastomoses were present in 35/183 (19.1%) of TTTS and in 12/24 (50%) IUGR patients. Of these, the hemodynamic equator was visible in 8/35 (22.8%) TTTS patients (all in stage III, and mostly in atypical stage III) and in 6/12 (50%) IUGR patients (overall 14/47, 29.8%). Of the 14 patients with a visible hemodynamic equator, 13 (92.8%) AA anastomoses showed unidirectional (9/13, 69.2% from the smaller to the larger twin) flow, and only 1/14 (7.1%) showed bi-directional flow. CONCLUSION: The hemodynamic equator is visible in approximately 30% of patients with AA anastomoses. Within this group, most AA anastomoses behave as functional arteriovenous anastomoses, and the direction of flow can be from the smaller to the larger twin or vice versa. The data suggest a correlation between sonographic findings and placental vascular design, also implying possible interfetal oxygenation differences. Further assessment of the functional behavior of AA anastomoses is warranted to understand the pathophysiology of TTTS and selective IUGR.

Multiple G-protein-coupled receptors mediate presynaptic inhibition at single excitatory synapses in the rat visual cortex.

Modulation of excitatory synaptic transmission by agonists for several neurotransmitter receptors was investigated at intrinsic cortical synapses derived from single presynaptic neurons. Excitatory postsynaptic currents (EPSCs) were recorded from layer 5 pyramidal neurons in the rat visual cortex in response to minimal stimulation within the same layer. 5-hydroxytryptamine, adenosine, baclofen, carbachol and DCG-IV all suppressed EPSCs with an increase in paired-pulse ratio. These agonists reduced the frequency of miniature EPSCs without significantly affecting their amplitude distribution. These results suggest that glutamatergic excitatory transmission in the neocortex is under the control of presynaptic inhibition mediated by multiple neuromodulator receptors co-expressed in single presynaptic terminals.

Neonatal periventricular leukomalacia preceded by fetal periventricular echodensity.

OBJECTIVE: The purpose of this prospective study is to verify whether fetal periventricular echodensity (PVE) precedes neonatal periventricular leukomalacia (PVL). METHODS: Fetal brains were studied with transvaginal scan in 63 high-risk fetuses from 17 to 32 weeks of pregnancy, PVE echogenicity was quantified with ultrasonic histogram, and neonatal brains and clinical courses were studied after birth. RESULTS: No fetal cystic PVL was found, instead, fetal PVE was detected in 42 fetuses. The quantified echogenicity value was higher in PVE than in normal brain. Four cases developed neonatal PVL among 28 preterm and 1 among 14 term births. Neonatal PVL developed in the 23 cases of persistent fetal PVE, whereas no neonatal PVL was found when fetal PVE was negative or disappeared. Cord compression signs were common in PVL cases. CONCLUSION: Neonatal PVL was preceded by antepartum persistent fetal PVE in the present study.

Spinocerebellar ataxia type 6 mutation alters P-type calcium channel function.

Abnormal CAG repeat expansion in the alpha1A voltage-dependent calcium channel gene is associated with spinocerebellar ataxia type 6, an autosomal dominant cerebellar ataxia with a predominant loss of the Purkinje cell. A reverse transcriptase-polymerase chain reaction analysis of mRNA from mouse Purkinje cells revealed a predominant expression of the alpha1A channel lacking an asparagine-proline (NP) stretch in the domain IV (alpha1A(-NP)). Human alpha1A channels carrying various polyglutamine length with or without NP were expressed in HEK293 cells, and channel properties were compared using a whole-cell voltage clamp technique. alpha1A(-NP), corresponding to P-type channel, with 24 and 28 polyglutamines found in patients showed the voltage dependence of inactivation shifting negatively by 6 and 11 mV, respectively, from the 13 polyglutamine control. Contrarily, the alpha1A channel with NP (alpha1A(+NP)), corresponding to Q-type channel, with 28 polyglutamines exhibited a positive shift of 5 mV. These results suggest that altered function of alpha1A(-NP) may contribute to degeneration of Purkinje cells, which express predominantly alpha1A(-NP), due to the reduced Ca(2+) influx resulting from the negative shift of voltage-dependent inactivation. On the other hand, other types of neurons, expressing both alpha1A(-NP) and alpha1A(+NP), may survive because the positive shift of voltage-dependent inactivation of alpha1A(+NP) compensates Ca(2+) influx.

[A case of successful palliative operation of asplenia syndrome with total anomalous pulmonary venous return in young infant].

We reported a successful palliative operation for asplenia syndrome with total anomalous pulmonary venous return (TAPVR Ia) in an infant. The boy was suffering from cyanosis and tachypnea. He was diagnosed as asplenia syndrome with TAPVR and hiatus hernia. After he was admitted to our hospital, pulmonary congestion gradually progressed in a month. At 58 days of age, a palliative operation (repair of TAPVR and pulmonary artery banding with band of 20 mm in length) was performed. The postoperative course was uneventful. At 114 days of age, he underwent curative operation for hiatus hernia without cardiac failure. Postoperative cardiac catheterization at 179 days of age showed appropriate pulmonary artery pressure. We emphasize that pulmonary artery banding which is tighter than usual well controls pulmonary blood flow, although the length of the band in each case should be considered individually.

Cloning and characterization of two human cDNAs encoding the mRNA capping enzyme.

Previous studies demonstrated that the mammalian mRNA capping enzyme is a bifunctional enzyme containing RNA 5'-triphosphatase and mRNA guanylyl-transferase activities in a single polypeptide. In yeast, both the above activities are separated into two different subunits, alpha and beta, the genes for which we have cloned recently. It is thus interesting to compare the structural and functional relationships between the mammalian and yeast capping enzymes. Here we isolated two human cDNAs encoding mRNA capping enzymes termed hCAP1a and hCAP1b which encode 597 and 541 amino acids, respectively. They are different only at the region coding for the C-terminal portion of the enzyme. Comparison of the deduced amino acid sequences with other cellular and viral capping enzymes showed that all the regions conserved among mRNA guanylyltransferases are observed in our clones except one conserved C-terminal region which was absent in the hCAP1b protein. The purified recombinant hCAP1a gene product, hCAP1a, exhibited both RNA 5'-triphosphatase and mRNA guanylyltransferase activities. Deletion mutant analysis of hCAP1a showed that the N-terminal 213 amino acid fragment containing a tyrosine specific protein phosphatase motif catalyzed the RNA 5'-triphosphatase activity and the C-terminal 369 amino acid fragment exhibited the mRNA guanylyltransferase activity. On the other hand, hCAP1b showed RNA 5'-triphosphatase activity, but neither enzyme-GMP covalent complex formation nor cap structure formation was detected.

[Ca2+ channels in the central nervous system].

Roles of Ca2+ channels in physiological functions of mammalian central synapses were discussed from a system-oriented point of view. In the presynaptic terminals of the mammalian CNS so far studied, synaptic transmission is mediated by the subclass of Ca2+ channels designated as the N-type (alpha 1B channels) and/or by that designated as the P/Q-type (alpha 1A channels). In some central synapses such as those between neocortical pyramidal neurons, synaptic transmission is presynaptically suppressed by various transmitter-modulators. Our electrophysiological data indicate that the receptors for amines, glutamate, GABA and adenosine co-exist on individual terminals, and they exert a common modulatory effect on synaptic transmission. Details of the intracellular cascade, i.e., G-protein and Ca2+ channel subtypes that are linked in this modulation, remain to be elucidated. Although the direct 'membrane delimited' action of G-proteins on Ca2+ channels is strongly suggested as a modulatory mechanism by the resemblance to the modulation observed in other neurons, the indirect second messenger pathways, however, may also be involved in the control of Ca2+ channels. Postsynaptically located Ca2+ channels are considered to play important roles in the regulation of neuronal excitability and synaptic plasticity. Individual dendritic spines apparently serve as a primary unit in an increase in Ca2+ level. This compartmentalized increase of Ca2+ seems essential for determining plastic changes of the synaptic efficacy in those particular spines. There is ample evidence indicating that the postsynaptic Ca2+ channels are involved in this Ca2+ transient. In order to understand the physiological significance of Ca2+ channels in CNS functions, further elucidation of channel subtypes, intracellular cascades of the modulator actions and characterization of the channel modifications will be essential.

Coincident induction of K rev-1/rap 1A, rap 1B and H-ras mRNAs in the rat spinal cord by noxious stimulation.

Two cDNA fragments, K rev-1/rap 1A and rap 1B, were amplified from total cellular RNA of the rat spinal cord by reverse transcription-polymerase chain reaction with a set of oligonucleotide primers specific for the human rap 1A cDNA. We report here using Northern blot analysis with these cDNA probes that noxious stimulation causes a marked and coincident increase in rap 1A, rap 1B and H-ras mRNAs in the rat spinal cord. This suggests that Rap 1 participates in sensory processing in spinal neurons in parallel with Ras.

Histometry and three-dimensional image reconstruction of the lung in congenital diaphragmatic hernia.

A small lung capacity, hypoplasia of the airway system, and abnormalities of the pulmonary artery system have been demonstrated as pathologic characteristics of congenital diaphragmatic hernia, but opinions have differed on the degree of hypoplasia of the acinus and terminal airspace. In this study, acinar size, mean wall thickness of the terminal airspace, an surface area of the terminal airspace were histometrically evaluated in four clinical cases. In addition, the pulmonary artery system was investigated by computerized three dimensional image reconstruction. Hypoplasia of the lung acinus and terminal airspace was observed in all four cases, and hypoplasia was more marked as lung capacity decreased. Thickening of the walls of pulmonary arterioles was confirmed, and previously undescribed abnormal branching of the pulmonary artery was recorded.

K rev-1 protein is abundantly expressed in the rat spinal cord.

The K rev-1 gene, which was originally identified as a dominantly functioning tumor suppressor gene inducing a flat revertant of a v-K-ras-transformed NIH 3T3 cell line, was abundantly expressed in the mammalian brain [Kitayama et al. (1989) Cell 56, 77-84]. To investigate where K rev-1 and its family ras proteins are distributed in the central nervous system, we isolated the membrane fractions from several regions of the brain and spinal cord of rats by subcellular fractionation and analyzed those proteins by immunoblot analysis with the specific monoclonal antibodies, K rev-1 protein was detected at the highest level in the spinal cord among areas of the central nervous system which included cerebral cortex, cerebellum, hippocampus, and olfactory bulb. On the other hand, ras proteins were found at similar levels in these regions. Within the spinal cord, K rev-1 and ras proteins were detected at a comparable level in the ventral and dorsal parts, while they were much less in the dorsal root ganglion than in the spinal cord. They showed the differential expression during early postnatal development: K rev-1 protein increased and ras proteins were at relatively high levels. When K rev-1 and ras proteins were examined in synaptosomes from the lumbar spinal cord of newborn rats, most of them were detected not in the synaptic vesicles but in the synaptic plasma membranes. K rev-1 protein as well as ras proteins might be involved in neuronal functions in the spinal cord such as sensory processing and motor control.

[The relationship between flow velocity waveforms of umbilical and fetal middle cerebral arteries and cord blood gas values].

Umbilical artery (UA) and fetal middle cerebral artery (MCA) flow velocity waveforms were obtained from 55 fetuses just prior to elective cesarean section at 36-39 weeks of gestation and the resistance index (RI) was calculated for each waveform. Cord blood samples were obtained from both the umbilical artery and the vein at cesarean section and the blood gas values were measured immediately. The coefficients of correlation between the cord blood gas values and the resistance indices were obtained. 1. UA-RI had a significant negative correlation with pH and Po2, and a positive correlation with Pco2. 2. MCA-RI had a significant positive correlation with pH and Po2, and a negative correlation with Pco2. 3. The UA-RI/MCA-RI ratio had a significant negative correlation with pH and Po2, and a positive correlation with Pco2. 4. The best correlation was found in the UA-RI/MCA-RI ratio, and the UA-RI, MCA-RI and UA-RI/MCA-RI ratios had a closer correlation with umbilical arterial blood gas values than with umbilical venous blood gas values. A Doppler study of fetal blood distribution would be a useful method in the noninvasive assessment of the fetal blood gas state at 36-39 weeks of gestation.

[Pathology of the anomalous choledocho-pancreatic junction--action of pancreatic juice on the biliary tract].

The mechanism of action of pancreatic juice on the biliary tract was investigated in a 5-year-old girl with choledochal cyst and animal models of the anomalous choledocho-pancreatic junction produced by pancreatico-cholecystostomy in 26 dogs. The results are as follows: Pancreatic enzymes are activated when bile and pancreatic juice are mixed in the biliary tract. Successively, lysolecithin and free fatty acids are produced by hydrolysis of lecithin in bile with phospholipase A2. These substances including phospholipase A2 destroy the mucosal barrier. The initial site receiving mucosal damage appears to be the epithelial apical cell membrane. The transfer of phospholipase A2 but not amylase from the biliary tract to the blood stream was suggested by comparing enzyme activity of portal and hepatic venous blood. The presence of some mutagenic substances in the contents of the choledochal cyst was confirmed by Ames assay and Rec-assay. This suggests that activated pancreatic enzymes and successively produced harmful substances in the anomalous choledocho-pancreatic junction are responsible for not only inflammatory but positively carcinogenic action on the biliary tract. In conclusion, the anomalous choledocho-pancreatic junction requires operative separation of the bile duct from the pancreatic duct despite the presence or absence of a choledochal cyst.

[Significance of fibrinopeptide A as an indicator for coagulative analysis in thrombotic diseases].

This study was made to know the significance of fibrinopeptide A(FPA) as an indicator for coagulative analysis in thrombotic diseases. In normal control subjects (n=21), values of FPA by the radioimmunoassay were 0.5 +/- 1.4 ng/ml (mean +/- SD). In animal models, using Lyoplastin (tissue thromboplastin, n=5) or Ancrod (n=5) to piglets, plasma FPA levels elevated rapidly as a reflection of fibrin formation, and these changes of FPA were found to be most rapid and sensitive among the indicators for coagulation and fibrinolysis. In patients with thrombosis (n=32), elevated FPA levels (14.7 +/- 13.8 ng/ml) and beta-thromboglobulin (beta-TG)(86.1 +/- 65.6 ng/ml) were found. FPA levels in these patients positively correlated to beta-TG (r=0.5539, P less than 0.05) and inversely to fibrinogen (fbg) (r= -0.3622, P less than 0.05). In patients with acute myelocytic leukemia (AML, n=112), acute promyelocytic leukemia (APL, n=18) and acute lymphocytic leukemia (ALL, n=15), mean FPA levels in patients with active signs and symptoms were significantly higher (AML: 13.5 ng/ml, APL: 20.8 ng/ml, ALL: 12.4 ng/ml) than those examined during remission states (AML: 7.7 ng/ml, P less than 0.02, APL: 3.9 ng/ml, P less than 0.01, ALL: 2.7 ng/ml, P less than 0.01). FPA levels in patients with APL inversely correlated to fbg (r= -0.6399, P less than 0.01). In patients with lung cancer (n=75), mean FPA level in advanced stage (17.7 ng/ml, n=67) were significantly higher than those examined in early stage 6.5 ng/ml, n=8, P less than 0.001). In patients with acute disseminated intravascular coagulation (n=12), prolonged prothrombin time and activated partial thromboplastin time, severely reduced fbg and platelets, and remarkably elevated fibrin degradation product were found. Elevated FPA and beta-TG levels were also found (FPA: 23.5 +/- 15.0 ng/ml, beta-TG: 100.0 +/- 63.0 ng/ml). In five patients with thrombotic diseases who were treated successfully with 12500 IU of heparin per 12 hours (subcutaneous injection), plasma FPA levels were reduced to near normal levels quicker than changes of other indicators. These clinical and experimental data suggested that FPA was an useful indicator for active coagulation process.