Anomalous right coronary artery from the pulmonary artery in Taussig-Bing anomaly

The presence of associated anomalies in patients with double-outlet right ventricle can significantly alter surgical intervention. Preoperative delineation of these anomalies can facilitate surgical planning and improve outcome. We describe a case in which the right coronary artery and anterior descending coronary artery arose from the pulmonary artery in a patient with double-outlet right ventricle with subpulmonary ventricular septal defect (Taussig-Bing anomaly). Recognition of this important anomaly prevented significant intraoperative myocardial damage by altering techniques of cardioplegia administration for myocardial preservation.     

NO/cGMP pathway is involved in exocrine secretion from rat pancreatic acinar cells

OBJECTIVE: To identify factors associated with the initiation of breast-feeding in a predominantly Puerto Rican population living in inner-city Hartford, Conn. DESIGN: Retrospective study of 144 Latino women (mean +/- standard deviation age = 26.3 +/- 5.7 years) with children at least 1 year old but younger than 6 years old (mean +/- standard deviation age = 3.0 +/- 1.2 years) at the time of the survey. Women were recruited from agencies sponsoring health programs for mothers and children. They were interviewed in their homes (69%) or at the Hispanic Health Council, Hartford, Conn (31%). SUBJECTS/SETTING: Low-income Latino women who had at least 1 preschooler at the time of the interview. The women lived in inner-city Hartford, and the overwhelming majority were Puerto Rican and received welfare assistance and food stamps. Seventy-eight percent of the women chose to be interviewed in Spanish; the other 22% were interviewed in English. STATISTICAL ANALYSES: Explanatory variables that related to breast-feeding initiation (P < or = .2) in bivariate chi 2 analyses were entered into a multivariate logistic regression model that was reduced using backward stepwise elimination procedures. RESULTS: Multivariate analyses indicated that breast-feeding the previous child, shorter length of maternal residence in the United States, not receiving prenatal bottle-feeding advice, more recent birth, and higher birth weight were positively associated with breast-feeding initiation. A major reason for choosing not to breast-feed was that women felt socially uncomfortable doing it. APPLICATIONS: Breast-feeding initiation was more likely in Latino women who received prenatal breast-feeding counselling and postpartum support. Mothers of low-birth-weight infants and women breast-feeding for the first time may need additional help. These findings can be used by programs like the Special Supplemental Nutrition Program for Women, Infants, and Children to increase breast-feeding initiation.     

Inhibition of platelet function by A02131-1, a novel inhibitor of cGMP-specific phosphodiesterase, in vitro and in vivo

The effect of A02131-1 [3-(5'-hydroxymethyl-2'-furyl)-1-benzyl thieno (3,2-c)pyrazole], a cGMP-specific phosphodiesterase (PDE) inhibitor, on platelet function was investigated. The compound was found to inhibit the aggregation of and adenosine triphosphate (ATP) release from human platelet-rich plasma and washed platelets that were induced by aggregation inducing drugs such as arachidonic acid (AA), collagen, U46619, platelet-activating factor (PAF), adenosine diphosphate (ADP) and A23187, and the inhibitory effect was concentration-dependent. A02131-1 also disaggregated the performed platelet aggregates induced by these inducers. Thromboxane B2 (TXB2) formations caused by collagen, PAF, ADP, and A23187 were inhibited by A02131-1 at concentrations that did not affect the AA-induced formation of TXB2 and prostaglandin D2 (PGD2). A02131-1 suppressed both the generation of inositol 1,4,5-triphosphate (IP3) and the increase of intracellular Ca2+ concentration stimulated by these aggregation inducers. A02131-1 was shown to increase the cAMP and cGMP levels in platelets and the extent was found to be dependent on concentration as well as time. A02131-1 increased the cAMP level much more slowly than the cGMP level. Activities of adenylate cyclase, guanylate cyclase, and PDEs (type I and III) were not altered by A02131-1. However, the activity of cGMP-specific PDE (type V) was inhibited by A02131-1. The antiplatelet aggregation activity and the effect on raising cAMP level of A02131-1 were both potentiated by prostaglandin E1 (PGE1). In the mouse tail bleeding test, A02131-1 was clearly shown to be more effective than dipyridamole in prolonging the tail bleeding time of conscious mice. These data indicate that A02131-1 is a cGMP-specific PDE (type V) inhibitor in human platelets.     

Cytogenetic abnormalities in pediatric myelodysplastic syndrome: a report of three cases

Three consecutive cases of pediatric myelodysplastic syndrome (MDS) diagnosed over a three-year period in Queen Mary Hospital, Hong Kong, were described. Depending on the classification system used, they comprised two cases of chronic myelomonocytic leukemia (CMMoL) of which one can be reclassified as juvenile chronic myeloid leukemia (JCML) and one cases of refractory anemia with excess of blasts (RAEB) or an alternative diagnosis of atypical CML. Cytogenetic abnormalities were detected in all of them on examination of bone marrow cells. Of the two CMMoL, one had monosomy 21, whereas the other had hypodiploidy. The patient with RAEB had a complex karyotype of 46,X,del(X)(q24),t(1;7) (p22;q32),add(15)(q26)(8). The balanced translocation (1;7) seen in this patient was exceedingly rare and, to the best of our knowledge, was reported only twice in the literature. The karyotypic abnormalities that we saw in our patients were not well recognized in pediatric MDS. This report emphasizes the importance of cytogenetic study in children suspected of suffering from MDS, which remains a rare disorder of childhood, and a need to rationalize current classification schemes.     

A novel role of ImmE7 in the autoregulatory expression of the ColE7 operon and identification of possible RNase active sites in the crystal structure of dimeric ImmE7

Site-specific cleavage of mRNA has been identified in vivo for the polycistronic colicin E7 operon (ColE7), which occurs between G and A nucleotides located at the Asp52 codon (GAT) of the immunity gene (ceiE7). In vitro, this specific cleavage occurs only in the presence of the ceiE7 gene product (ImmE7). The crystal structure of dimeric ImmE7 has been determined at 1.8 A resolution by X-ray crystallographic analysis. We found that several residues located at the interface of dimeric ImmE7 bear surprising resemblance to the active sites of some RNases. These results suggest that dimeric ImmE7 may possess a novel RNase activity that cleaves its own mRNA at a specific site and thus autoregulates translational expression of the downstream celE7 gene as well as degradation of the upstream ceaE7 mRNA.     

Increased prevalence of hypertension and long-term arsenic exposure

A possible role of endothelin (ET)-1 in mediating hypoxic pulmonary vasoconstriction (HPV) was examined by comparing haemodynamic differences between ET-1-induced vasoconstriction and HPV in isolated perfused rat lungs. An ETA receptor antagonist (BQ123) was also employed to assess the effects of ET-1. The pulmonary arterial pressure (Ppa) was significantly increased by alveolar hypoxia (3% O2) and by ET-1 (5 nM). The pulmonary microvascular pressure was not changed by hypoxia, but increased more than two-fold by ET-1 (P < 0.01). Hypoxia significantly increased pulmonary arterial resistance (P < 0.01) while ET-1 significantly increased pulmonary venous resistance (P < 0.01), and slightly increased arterial resistance. Lung weight was increased by ET-1 and decreased by hypoxia, accompanied by similar Ppa responses in both cases. BQ123 (10(-6) M and 10(-5) M) did not influence the changes in Ppa and lung weight induced by hypoxia or angiotensin II (0.3 micrograms). BQ123 did, however, suppress (P < 0.05) the increase in Ppa and lung weight induced by 5 nM ET-1. Thus, it appears unlikely that ET-1 is involved in changes in pulmonary vascular tone during acute HPV.     

Acute alcohol blocks neurosteroid modulation of synaptic transmission and long-term potentiation in the rat hippocampal slice

Effects of ethanol (22 mM) on the modulation of synaptic transmission and long-term potentiation (LTP) by the neurosteroid dehydroepiandrosterone sulfate (DHEAS; 10 microM) was examined in the in vitro rat hippocampal slice preparation. The synaptic responses were elicited by Schaffer collateral stimulation and recorded extracellularly in the somatic and dendritic regions of CA1 pyramidal neurons. LTP induction produced an increase (approximately 55% to 75%) in the amplitude of synaptic responses in ethanol and ethanol plus DHEAS (ethanol/DHEAS) treated slices. These increases were significantly smaller than the approximately 130% increase observed previously in slices treated with DHEAS, but were not significantly different from the approximately 82% increase observed in control slices. These results indicate that an ethanol/DHEAS interaction prevents the enhancement of LTP normally observed with DHEAS treatment of hippocampal slices. An ethanol/DHEAS interaction also altered DHEAS's effects on individual synaptic components of the synaptic response to Schaffer collateral stimulation. Ethanol applied before but not after DHEAS prevented DHEAS's enhancement of the NMDA receptor-mediated synaptic component. DHEAS's depression of the GABAA receptor-mediated synaptic component was also blocked by ethanol. Ethanol or DHEAS individually had no effect on the AMPA receptor-mediated synaptic component, but application of ethanol after DHEAS resulted in a small enhancement of this synaptic component, an effect that was not observed if ethanol was applied before DHEAS. These results show that ethanol and DHEAS interact, altering DHEAS's effects on synaptic transmission and LTP in the hippocampus. Such an interaction may be involved in ethanol's actions on the CNS and raises the possibility that ethanol and DHEAS may act via a common site or pathway.