Ln3I5(S2N2)(S2)(THF)10 - a new type of molecular compounds.

Unprecedented complexes of the composition Ln3I5(S2N2)(S2)(THF)10 were obtained in the reactions of neodymium and dysprosium iodide-nitrides with sulfur. The inorganic core of the molecules contains the cyclic fragments Ln(µ-S2)Ln, LnSNSN and LnSN. Ten of the fourteen atoms of the core are coplanar, the remaining four S2 and I2 atoms lie in the other two orthogonal planes. The dysprosium complex upon excitation with UV light exhibits the metal-centered luminescence characteristic of the Dy(3+) ion. Geometric parameters of the molecules, computational data, electron spectroscopy and fluorescence suggest the existence of some conjugation in the mentioned heterocycles.

Expression of the tumour suppressor gene CADM1 is associated with favourable outcome and inhibits cell survival in neuroblastoma.

Cell adhesion molecule 1 (CADM1) is a putative tumour suppressor gene, which is downregulated in many solid tumours. In neuroblastoma, loss of CADM1 expression has recently been found in disseminated tumours with adverse outcome, prompting us to investigate its role in neuroblastoma tumour progression. Oligonucleotide-microarray analysis of 251 neuroblastoma specimens demonstrated that CADM1 downregulation is associated with unfavourable prognostic markers like disseminated stage 4, age >18 months, MYCN amplification and chromosome 11q alterations (P<0.001 each). Furthermore, low CADM1 expression was significantly correlated with unfavourable gene expression-based classification (P<0.001) and adverse patient outcome (P<0.001). Bisulphite sequencing and genetic analysis of 18 primary neuroblastomas suggested that neither haploinsufficiency nor hypermethylation is regularly involved in CADM1 gene silencing in neuroblastoma, which is in contrast to results obtained in other malignancies. In addition, no mutations disrupting the CADM1 reading frame were found in 25 primary neuroblastomas. Over-expression of CADM1 in neuroblastoma cells resulted in significant reduction of proliferation, viability and colony formation in soft agar. Collectively, our results suggest that downregulation of CADM1 tumour suppressor gene expression is a critical event in neuroblastoma pathogenesis resulting in tumour progression and unfavourable patient outcome.

Heparin contamination in coagulation testing and a protocol to avoid it and the risk of inappropriate FFP transfusion.

Artifactual heparin contamination of blood samples drawn for coagulation testing is an ongoing problem. A retrospective analysis of activated partial thromboplastin times (APTTs) greater than 45 seconds from patients on neither heparin nor Coumadin (Dupont, Wilmington, DE) therapy shows complete correction of the APTT to normal in 39% of such samples after treatment with heparinase. Recheck of samples with significantly prolonged APTTs after treatment with heparinase is proposed as the best method to avoid inappropriate transfusion of fresh frozen plasma.

Lactate dehydrogenase isoenzyme composition of human platelets.

The LDH isoenzyme composition of 12 platelet preparations was determined by electrophoresis. The mean (+/- SD) percentages of LDH-1, LDH-2, LDH-3, LDH-4, and LDH-5 were 16.6 +/- 1.7, 30.1 +/- 1.0, 34.2 +/- 1.3, 18.2 +/- 1.3, and 0.9 +/- 1.1, respectively. In comparison with previous data, these data show identical ranking of the prevalence of each isoenzyme but significantly different percentages, particularly of LDH-1 and LDH-4. The release of platelet LDH by freezing and thawing differed little from that by homogenization.

Heritable alpha 2-macroglobulin deficiency in a patient with arterial thrombosis: alpha 2-macroglobulin deficiency Irvine.

A heritable deficiency in α(2)-macroglobulin (α(2)M) was identified in a 61-year-old man with arterial thrombosis. Plasma α(2)M levels among the patient's symptom-free relatives consistently ranged from 43 to 55 percent of laboratory mean-normal values. The new α(2)M variant displayed retarded anodal immunoelectrophoretic mobility when studied in plasma and serum. The affected members of this lineage showed no evidence of acquired or inherited thrombotic or consumptive derangements involving other plasma proteins. The significance of a possible causal association between α(2)M deficiency and the predisposition to arterial thrombosis is considered. The uncomplicated use of streptokinase and urokinase to treat the reference patient's arterial thrombosis is described. Recommendations are made for the adoption of a descriptive nomenclature. The new familial deficiency is tentatively designated α(2) (+)-macroglobulin deficiency Irvine.

Trials of commercial reagents in anion-exchange coagulation procedures: ortho diagnostics.

The suitability of Ortho Diagnostics one-stage prothrombin time (PT) reagent (Ortho Brain Thromboplastin) and activated partial thromboplastin (aPTT) reagent (Activated Thrombofax) has been evaluated for use in conjunction with the anion-exchange heparin removal maneuver. The PT/HR and aPTT/HR are tests used to follow the anticoagulant influence of coumarins when heparin also is being administered. After establishing a coumarin therapeutic range for Activated Thrombofax, a parallel trial was conducted with Ortho Brain Thromboplastin on coumarin-treated patient plasmas. Determinations also were made after heparin (0.2 mu/mL) was added and then removed by ECTEOLA microchromatography columns. Ortho Brain Thromboplastin was found to induce a shortening bias associated with a spurious improvement in the precision of tests run on anion-exchange treated plasmas that potentially could result in coumarin overdosage. The systematic error did not appear to result either from protracted incubation or the activation of prekallikrein, high molecular weight kininogen, Factor XI or XII. This reagent was found to perform appropriately with plasma not exposed to ECTEOLA. Activated Thrombofax gave reliable and reproducible results before and after heparin removal. This aPTT reagent could be used in the aPTT/HR anticoagulant surveillance scheme.

Use of activated partial thromboplastin time to monitor coumarin anticoagulation.

The activated partial thromboplastin time after heparin removal (aPTT/HR) is an anionexchange procedure that permits the unobstructed monitoring of the progress of coumarin anticoagulation by removing interfering heparin. An all-intrinsic-pathway anticoagulant surveillance scheme based upon the aPTT/HR has been proposed and provisionally tested. The adoption of the new scheme will depend upon the identification of partial thromboplastins that are as predictable and reliable as the tissue thromboplastins in modern one-stage prothrombin times. In this study, the commercial APTT Reagent and Simplastin performed with equal sensitivity and specificity when evaluated by means of prothrombin group factor assays on coumarintreated subject plasmas. It is concluded that this commercial partial thromboplastin (1) is capable of being used for the purpose of following heparin, heparin plus coumarin, and coumarin anticoagulation; (2) is potentially able to identify more of the inherited and acquired derangements that can lead to anticoagulation-associated hemorrhage; and (3) is a universally available alternative to the traditional anticoagulant monitoring approach.

Activated partial thromboplastin time after heparin removal (aPTT/HR) in a new scheme of anticoagulant monitoring.

Activated partial thromboplastin time after heparin removal (aPTT/HR), a test employing anion exchange chromatography, was devised as an alternative to the prothrombin time after heparin removal (PT/HR) to monitor simultaneous anticoagulation with heparin and coumarins. The potential utility of the aPTT/HR was assessed by performing parallel PTs and aPTTs on 62 consecutive plasmas from coumarin-treated outpatients. All samples had 0.2 units/ml of heparin added and then removed to see if the maneuver influenced therapeutic group assignment. In no instance did reassignment occur. A conditional Irwin-Fisher test (P = 0.000604) and a special multinomial trial analysis (P = 0.002) indicated that the aPTT would be at least comparable to the PT for following coumarin antithrombotic prophylaxis. Since the heparin removal procedure had no influence on therapeutic categorization, the same statistical proof could be applied to the relationship between aPTT/HR and PT/HR. This study indicates that the aPTT can be used to monitor all stages of heparin and /or coumarin anticoagulation.