Percutaneous coronary intervention with adjunctive abciximab and clopidogrel in a patient with chronic idiopathic thrombocytopaenic purpura

The use of the antiplatelet agents abciximab and clopidogrel is now accepted therapy in percutaneous coronary intervention. We present a case in which these agents were used in a patient with idiopathic thrombocytopaenic purpura and a platelet count of 40x10(9)/l undergoing primary multivessel coronary stenting. This case shows that unstable coronary syndromes can occur in patients with thrombocytopaenia and that antiplatelet agents may be used safely in this context.     

Buccal Spectral Markers for Lung Cancer Risk Stratification

Lung cancer remains the leading cause of cancer deaths in the US with >150,000 deaths per year. In order to more effectively reduce lung cancer mortality, more sophisticated screening paradigms are needed. Previously, our group demonstrated the use of low-coherence enhanced backscattering (LEBS) spectroscopy to detect and quantify the micro/nano-architectural correlates of colorectal and pancreatic field carcinogenesis. In the lung, the buccal (cheek) mucosa has been suggested as an excellent surrogate site in the “field of injury”. We, therefore, wanted to assess whether LEBS could similarly sense the presence of lung. To this end, we applied a fiber-optic LEBS probe to a dataset of 27 smokers without diagnosed lung cancer (controls) and 46 with lung cancer (cases), which was divided into a training and a blinded validation set (32 and 41 subjects, respectively). LEBS readings of the buccal mucosa were taken from the oral cavity applying gentle contact. The diagnostic LEBS marker was notably altered in patients harboring lung cancer compared to smoking controls. The prediction rule developed on training set data provided excellent diagnostics with 94% sensitivity, 80% specificity, and 95% accuracy. Applying the same threshold to the blinded validation set yielded 79% sensitivity and 83% specificity. These results were not confounded by patient demographics or impacted by cancer type or location. Moreover, the prediction rule was robust across all stages of cancer including stage I. We envision the use of LEBS as the first part of a two-step paradigm shift in lung cancer screening in which patients with high LEBS risk markers are funnelled into more invasive screening for confirmation.     

Contrasting population structure from nuclear intron sequences and mtDNA of humpback whales

Powerful analyses of population structure require information from multiple genetic loci. To help develop a molecular toolbox for obtaining this information, we have designed universal oligonucleotide primers that span conserved intron-exon junctions in a wide variety of animal phyla. We test the utility of exon-primed, intron-crossing amplifications by analyzing the variability of actin intron sequences from humpback, blue, and bowhead whales and comparing the results with mitochondrial DNA (mtDNA) haplotype data. Humpback actin introns fall into two major clades that exist in different frequencies in different oceanic populations. It is surprising that Hawaii and California populations, which are very distinct in mtDNAs, are similar in actin intron alleles. This discrepancy between mtDNA and nuclear DNA results may be due either to differences in genetic drift in mitochondrial and nuclear genes or to preferential movement of males, which do not transmit mtDNA to offspring, between separate breeding grounds. Opposing mtDNA and nuclear DNA results can help clarify otherwise hidden patterns of structure in natural populations.      

High-Density Microarray of Small-Subunit Ribosomal DNA Probes

Ribosomal DNA sequence analysis, originally conceived as a way to provide a universal phylogeny for life forms, has proven useful in many areas of biological research. Some of the most promising applications of this approach are presently limited by the rate at which sequences can be analyzed. As a step toward overcoming this limitation, we have investigated the use of photolithography chip technology to perform sequence analyses on amplified small-subunit rRNA genes. The GeneChip (Affymetrix Corporation) contained 31,179 20-mer oligonucleotides that were complementary to a subalignment of sequences in the Ribosomal Database Project (RDP) (B. L. Maidak et al., Nucleic Acids Res. 29:173-174, 2001). The chip and standard Affymetrix software were able to correctly match small-subunit ribosomal DNA amplicons with the corresponding sequences in the RDP database for 15 of 17 bacterial species grown in pure culture. When bacteria collected from an air sample were tested, the method compared favorably with cloning and sequencing amplicons in determining the presence of phylogenetic groups. However, the method could not resolve the individual sequences comprising a complex mixed sample. Given these results and the potential for future enhancement of this technology, it may become widely useful.     

High-density microarray of small-subunit ribosomal DNA probes

Ribosomal DNA sequence analysis, originally conceived as a way to provide a universal phylogeny for life forms, has proven useful in many areas of biological research. Some of the most promising applications of this approach are presently limited by the rate at which sequences can be analyzed. As a step toward overcoming this limitation, we have investigated the use of photolithography chip technology to perform sequence analyses on amplified small-subunit rRNA genes. The GeneChip (Affymetrix Corporation) contained 31,179 20-mer oligonucleotides that were complementary to a subalignment of sequences in the Ribosomal Database Project (RDP) (B. L. Maidak et al., Nucleic Acids Res. 29:173-174, 2001). The chip and standard Affymetrix software were able to correctly match small-subunit ribosomal DNA amplicons with the corresponding sequences in the RDP database for 15 of 17 bacterial species grown in pure culture. When bacteria collected from an air sample were tested, the method compared favorably with cloning and sequencing amplicons in determining the presence of phylogenetic groups. However, the method could not resolve the individual sequences comprising a complex mixed sample. Given these results and the potential for future enhancement of this technology, it may become widely useful.     

Affinity chromatography in the industrial purification of plasma proteins for therapeutic use.

Affinity chromatography is a powerful technique for the purification of many proteins in human plasma. Applications cover the isolation of proteins for research purposes but also, to a large extent, for the production of therapeutic products. In industrial plasma fractionation, affinity chromatography has been found to be particularly advantageous for fine and rapid capture of plasma proteins from industrial plasma fractions pre-purified by ethanol fractionation or by ion-exchange chromatography. To date, affinity chromatography is being used in the production of various licensed therapeutic plasma products, such as the concentrates of Factor VIII, Factor IX, von Willebrand Factor, Protein C, Antithrombin III, and Factor XI. Most commonly used ligands are heparin, gelatin, murine antibodies, and, to a lesser extent, Cu(2+). Possible development of the use of affinity chromatography in industrial plasma fractionation should be associated to the current development of phage display and combinatorial chemistry. Both approaches may lead to the development of tailor-made synthetic ligands that would allow implementation of protein capture technology, providing improved productivity and yield for plasma products.     

Impact of Triton X-100 on alpha 2-antiplasmin (SERPINF2) activity in solvent/detergent-treated plasma

Large-pool solvent/detergent (SD) plasma for transfusion exhibits reduced alpha 2-antiplasmin (alpha2-AP; SERPINF2) functional activity. The reason for the loss of alpha2-AP has not been described and could be due to the SD incubation itself and/or to the processing steps implemented to remove the solvent and the detergent. We have studied alpha2-AP activity during six down-scale preparations of plasma virally-inactivated by 1% (v/v) TnBP combined with two different non-ionic detergents, either 1% Triton X-100 or 1% Triton X-45, at 31 degrees C for 4h. The SD-treated plasmas were then extracted with 7.5% (v/v) soybean oil, centrifuged at 3800 x g for 30 min, and subjected to hydrophobic interaction chromatography (HIC) to remove the SD agents. Control runs without TnBP and Triton were performed to evidence possible impacts of each process step on alpha2-AP activity. TnBP, Triton X-100, and Triton X-45 were measured at all stages of the processes to evaluate potential interferences with the alpha2-AP assay. Alpha 2-AP activity was about 10% that of starting plasma after 1% TnBP-1% Triton X-100 incubation and about 50% after oil extractions, centrifugation, and HIC. By contrast about 73% of the antiplasmin activity was found after the incubation with 1% TnBP and 1% Triton X-45, 88% after removal of the SD agents by oil extractions, 90% after centrifugation and 92% after HIC. The control runs performed without SD agents showed that the process steps did not affect the alpha2-AP activity. In conclusion, the agent altering alpha2-AP activity in SD-plasma is Triton X-100. The choice of detergents for the SD viral inactivation of therapeutic plasma fractions used in patients at risk of fibrinolysis should consider the impact on alpha2-AP activity.