Total anomalous pulmonary venous connection: surgical experience in Indians

BACKGROUND: We report a retrospective analysis of the demographic. morphological and clinical profiles of patients along with results of operative repair for total anomalous pulmonary venous connection. METHODS AND RESULTS: In the last 15 years, 248 patients (168 boys, 80 girls) underwent repair for total anomalous pulmonary venous connection. Their ages ranged from I day to 24 years (median 8 months) and 145 of them were < or = 1 year of age. The patients' weight ranged from 2 to 52 kg (median 5 kg). About 70% of patients (n = 174) were less than the 50th percentile of predicted weight for age and sex. The anomalous connection was supracardiac in 134 (54%), cardiac in 80 (32.2%), infracardiac in 9 (3.6%) and mixed in 25 (10.1%) patients. Fifty (20.2%) patients had obstructed drainage and 76 patients (30.2%) had moderate or severe pulmonary arterial hypertension. Forty-five patients (18.1%) had to be operated upon on an emergency basis. All the patients were operated upon using moderately hypothermic cardiopulmonary bypass. In 114 patients, circulatory arrest was used. There were 45 (19.1%) in-hospital deaths. The major causes of early death were pulmonary arterial hypertensive crisis in 19 (7.7%) and low cardiac output syndrome in 17 (6.9%) patients. Age < or = 1 year (odds ratio 2.16; 95% confidence interval: 1.22-3.82, p=0.008), severe pulmonary arterial hypertension (odds ratio 5.86; 95% confidence interval: 2-17, p=0.001), and need for emergency surgery (odds ratio 3.65; 95% confidence interval: 1.59-8.38, p=0.002) were independent risk factors for early death. Follow-up ranged from 1 to 180 months (median 48 months). There were 4 lake deaths. Actuarial survival at 12 years was 92.6% +/- 2.8%. CONCLUSIONS: In Indian circumstances, mortality continues to be high in infants with total anomalous pulmonary venous connection. Severe pulmonary arterial hypertension appears to be the most important predictor of operative mortality. Severe malnutrition, delayed diagnosis and late referrals possibly contribute to the high mortality.     

Identification of 32 novel mutations in the factor VIII gene in Indian patients with hemophilia A

Seventy-five unrelated hemophilia A patients from India were analyzed for factor VIII gene defects. Intron 22 inversion was identified in 22 patients and intron 1 inversion in 2 patients. In the remaining 51 patients without inversions screening the FVIII gene by denaturing high performance liquid chromatography (DHPLC) revealed 42 different mutations in 44 unrelated subjects. These included 14 missense, 7 nonsense, 9 splice site, 8 deletional, 3 insertional mutations and one indel mutation. Of these, 32 were novel gene alterations. The hotspots included intron 22 inversion, CpG and adenine runs.     

Risk factors for thrombosis in nonembolic cerebrovascular disease

Thirty-seven young patients (less than 42 years of age) presenting with sudden onset of idiopathic nonembolic cerebrovascular disease were evaluated for underlying prothrombotic factors. Activated protein C resistance (APC-R) was measured by Dahlback's method and the modified method using factor V-deficient plasma. Activities of antithrombin (AT) III, protein C and S were measured. Anticardiolipin antibody was estimated by ELISA and lupus anticoagulant by kaolin clotting tests. APC-R was the most common defect (21.62%) followed by AT III deficiency and presence of anticardiolipin antibodies (5.6% each). The latter two were present together in one case. It is thus concluded that APC-R is the most common defect underlying idiopathic nonembolic cerebrovascular infarction in young individuals.     

Hemophilia A: role of FVIIIC/vWF Ag in assisting linkage analysis for carrier detection.

Carrier detection for hemophilia A was carried out in 52 females from 30 families presenting to the Haematology Department AIIMS, using linkage analysis and factor VIIIC (FVIIIC)-von Willebrand factor (vWF) antigen assay. The allelic frequency for the marker Bcl 1 and Xba 1 was 0.58 and 0.54, respectively, for the positive alleles and 0.42 and 0.46, respectively, for the negative alleles. The heterozygosity frequency of Bcl I and Xba 1 was 0.65 and 0.55, respectively. Of the 52 females, 30 were mothers of hemophilic patients and 22 were sisters of hemophilic patients. Of the 30 mothers, positive family history was present in 14. In these patients, the defective X chromosome was tracked in 10, and in four the defective X chromosome could not be tracked because the mothers were homozygous for the marker used. Of the 16 mothers without a family history of disease, three were observed to be carriers based on linkage analysis and reduced factor VIII levels in mother/sister. Possible defective X chromosome was tracked in 11 mothers and five were noninformative because they did not show heterozygosity for the markers used. Using linkage analysis, nine of the 22 sisters were found to be definite carriers, 10 noncarriers, and three were noninformative. It is thus concluded that using Bcl 1 and Xba 1 linkage analysis, carrier status can be definitely ascertained in 50% females and this level of information can be increased to 61.5% by measuring FVIIIC/vWF antigen levels in them.     

Decreased expression of phospholipase C-beta 2 isozyme in human platelets with impaired function

Platelets from a patient with a mild inherited bleeding disorder and abnormal platelet aggregation and secretion show reduced generation of inositol 1,4,5-trisphosphate, mobilization of intracellular Ca2+, and phosphorylation of pleckstrin in response to several G protein mediated agonists, suggesting a possible defect at the level of phospholipase C (PLC) activation (see accompanying report). A procedure was developed that allows quantitation of platelet PLC isozymes. After fractionation of platelet extracts by high-performance liquid chromatography, 7 out of 10 known PLC isoforms were detected by immunoblot analysis. The amount of these isoforms in normal platelets decreased in the order PLC- gamma 2 > PLC-beta 2 > PLC-beta 3 > PLC-beta 1 > PLC-gamma 1 > PLC- delta 1 > PLC-beta 4. Compared with normal platelets, platelets from the patient contained approximately one-third the amount of PLC-beta 2, whereas PLC-beta 4 was increased threefold. These results suggest that the impaired platelet function in the patient in response to multiple G protein mediated agonists is attributable to a deficiency of PLC-beta 2. They document for the first time a specific PLC isozyme deficiency in human platelets and provide an unique opportunity to understand the role of different PLC isozymes in normal platelet function.     

Simultaneous device closure of muscular ventricular septal defect and pulmonary valve balloon dilatation.

Percutaneous closure of ventricular septal defect and pulmonary valvuloplasty appears to be an attractive modality when compared to surgical treatment for both lesions. We report successful transcatheter closure of muscular ventricular septal defect with pulmonary valve balloon dilation performed simultaneously in a 27-year-old woman. Technical considerations in such a setting are being discussed.     

Elastin-like polypeptides and their applications in anticancer drug delivery systems: a review

Abstract

Elastin-like polypeptides (ELPs) are large molecular weight biopolymers. They have been widely studied as macromolecular carriers for targeted delivery of drugs. The aim of the present article is to review the available information on ELPs (including our recent investigations), their properties, drug delivery applications to tumor sites and future perspectives. This review also provides information on the use of short synthetic ELPs for making ELP-drug conjugates, for targeted delivery of anticancer drugs. In the present review we also focus on the point that short ELPs can also be used for targeting anticancer drugs to tumor sites as they behave similar to long ELPs regarding their capacity to undergo inverse temperature transition (ITT) behavior.     

Superoxide does not mediate the acute vasoconstrictor effects of angiotensin II: a study in human and porcine arteries

OBJECTIVE: To investigate whether superoxide mediates angiotensin (Ang) II-induced vasoconstriction. METHODS: Human coronary arteries (HCAs), porcine femoral arteries (PFA) and porcine coronary arteries (PCAs) were mounted in organ baths and concentration-response curves to Ang II, the nitric oxide (NO) donor S-nitroso-N-acetylpenicillamine (SNAP) and the NAD(P)H oxidase substrate NADH were constructed in the absence and presence of superoxide inhibiting and activating drugs. Extracellular superoxide was measured using cytochrome c reduction. RESULTS: Ang II constricted both HCAs and PFAs. In HCAs, the NAD(P)H inhibitors diphenyleneiodonium (DPI) and apocynin, and the xanthine oxidase (XO) inhibitor allopurinol, but not the superoxide dismutase (SOD) mimetic tempol or the SOD inhibitor diethyldithiocarbamate (DETCA), reduced this constriction. Catalase potentiated Ang II in HCAs, indicating a vasodilator role for H2O2. DPI, tempol and SOD did not affect Ang II in PFAs. DPI, apocynin and allopurinol relaxed preconstricted HCAs. Although the relaxant effects of the NO donor SNAP in PCAs was reduced by DETCA, indicating that superoxide-induced constrictions depend on NO inactivation, the apocynin-induced relaxations were NO independent. Moreover, NADH relaxed all vessels, and this effect was blocked by KCl but not DPI or NO removal. Xanthine plus XO also relaxed HCAs and PCAs. Incubation of human or porcine arteries with Ang II or NADH did not result in detectable increases of extracellular superoxide within 1 h. CONCLUSIONS: Acute vasoconstriction by Ang II is not mediated via superoxide generated through NAD(P)H oxidase and/or XO activation. Such activation, if occurring, rather results in the generation of the vasodilator H2O2.     

Human platelet signaling defect characterized by impaired production of inositol-1,4,5-triphosphate and phosphatidic acid and diminished Pleckstrin phosphorylation: evidence for defective phospholipase C activation

Signal transduction on platelet activation involves phosphoinositide- specific phospholipase C (PLC)-mediated hydrolysis of phosphatidylinositides and formation of inositol-1,4,5-triphosphate [I(1,4,5)P3], which mediates Ca2+ mobilization, and diacylglycerol (DG), which activates protein kinase C (PKC) to phosphorylate a 47-kD protein (Pleckstrin). We studied these events in two related patients previously reported (Blood 74:664, 1989) to have abnormal aggregation and 14C-serotonin secretion, and impaired intracellular Ca2+ mobilization in response to several agonists. Thrombin-induced I(1,4,5)P3 and phosphatidic acid formation were diminished. Pleckstrin phosphorylation was impaired on activation with thrombin, platelet- activating factor, and ionophore A23187, but was normal with PKC activator 1,2-dioctonyl-sn-glycerol (DiC8). Ca2+ mobilization induced by guanosine triphosphate (GTP) analog guanosine 5'-0-(3 thiotriphosphate) (GTP gamma S) was diminished. Pretreatment with either A23187 or DiC8 did not correct the impaired adenine diphosphate- induced secretion; however, upon stimulation with A23187 plus DiC8, pleckstrin phosphorylation and secretion were normal, indicating that both PKC activation and Ca2+ mobilization are essential for normal secretion. We conclude that these patients have a unique inherited platelet defect in formation of two key intracellular mediators [I(1,4,5)P3 and DG] and in the responses mediated by them due to a defect in postreceptor mechanisms of PLC activation.