[Thrombosis of muscle veins of the crus in patients operated on for varicose disease].

UNLABELLED: The necessity of preventing venous thromboembolic complications in patients after endured surgical interventions for varicose disease remains a debatable problem. The study was aimed at assessing the incidence of deep vein thrombosis after phlebectomy and determining its clinical significance. MATERIAL AND METHODS: The authors carried out a prospective cohort study comprising a total of 86 patients (73 women and 13 men, aged from 16 to 64 years, the mean age 39.1±11.8 years) presenting with class C2-C4 varicose disease. All patients under conduction and tumescent anaesthesia were subjected to crossectomy, stripping, and miniphlebectomy. The operations lasted from 60 minutes to 3 hours 30 min (average duration--123±23 min). According to the Caprini score, in 58 patients the risk of thromboembolic complications was assessed as moderate (3-4 points), and in 28 patients as high (5 points and greater). In the postoperative period elastic compression was used in all patients, the activation began 1-2 hours after the operation. Anticoagulants in preventive doses were indicated in 6 patients due to the presence of additional risk factors. RESULTS: Ultrasonographic examination in the postoperative period revealed 3 (3.5%) cases of crural muscle vein thrombosis. Anticoagulation therapy was not indicated in these patients. Detecting thrombosis was followed by dynamic follow up. Ultrasonographic study revealed complete recanalization of thrombosed veins by the end of the second month of follow up. The incidence rate of thrombosis in the group with the moderate baseline risk of thrombosis amounted to 1.7% and in the group with high risk of thrombosis to 9.1% (p>0.1). CONCLUSION: Crossectomy, stripping of subcutaneous veins, and miniphlebectomy carried out under conduction and local anaesthesia are not significant risk factors for the development of thromboembolic complications.

MALDI-TOF mass spectrometric method for detection of hybridized DNA oligomers.

Two new approaches for nucleic acid hybridizations by MALDI-TOF mass spectrometry are described. Hybridization using genomic DNA without polymerase chain reaction was demonstrated. Total genomic DNA of bacteriophages bound to charge-modified nylon membranes was identified by the hybridization of species-specific oligonucleotide probes. lambda-Phage DNA and M13 were used for the test with good success. Since MALDI-TOF mass spectrometry can be used to measure the molecular weights of different probes, mass spectrometry can be used for the detection of hybridizations with multiple probes. We demonstrate that multiple-probe hybridization can be resolved by mass spectrometry. Six probes with different mass tag were used for hybridization on a single spot. MALDI-TOF mass spectrometry was successfully used to measure these probes simultaneously. This provides a simple nonradioactive method for multiplex hybridization analysis. It has the potential to drastically increase the speed for microarray hybridization analysis in the future.

Nonresonant MALDI of oligonucleotides: mechanism of ion desorption.

Oligonucleotide ions have been detected using matrix-assisted laser desorption/ionization (MALDI) under nonresonant laser irradiation of the sample. When mass resolution was not limited by adduct attachment to the analyte ions, the nonresonant MALDI spectra demonstrated better resolution than the spectra acquired with resonant ultraviolet irradiation. We found that preparation of thin-film samples on absorbing substrate surfaces was critical for the success of NR-MALDI. The possible acoustic mechanisms of ion formation and desorption are discussed.

Gender identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

A rapid, simple, and reliable gender determination of human DNA samples was successfully obtained using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Detection sensitivity reached 0.01 ng or less for DNA samples.

Detection of trinucleotide expansion in neurodegenerative disease by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Genotyping of the dentatorubral-pallidoluysian atrophy (DRPLA) locus in six patient samples, representing four normal individuals and two DRPLA patients, was successfully obtained using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). DRPLA is a dominantly inherited neurodegenerative disorder associated with the expansion of an unstable trinucleotide (CAG) repeat. The accurate determination of repeat length utilizing MALDI supports the use of this methodology for the analysis of genes containing unstable CAG trinucleotide repeats.

Sequencing DNA using mass spectrometry for ladder detection.

Sequencing of DNA fragments of 130 and 200 bp using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for DNA ladder detection was demonstrated. With further improvement in mass resolution and detection sensitivity, mass spectrometry shows great promise for routine DNA sequencing in the future.

Matrix-assisted laser desorption/ionization for short tandem repeat loci.

Matrix-assisted laser desorption/ionization was used for the detection of four base short tandem repeats (STR) for clinical samples using a time-of-flight mass spectrometer. Since STR plays an important role in genetic disease and human identification, this work indicates that laser desorption mass spectrometry has the potential to achieve rapid DNA typing for both forensic applications and genetic disease diagnosis.

Matrix-assisted laser desorption/ionization for sequencing single-stranded and double-stranded DNA.

The DNA sequence of a single-stranded and double-stranded template was determined. The templates were sequenced using the chain termination method and cycle sequencing method and detected by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The sequencing products were analyzed successfully without the laborious and expensive methods for removal of the template. Direct sequencing of the double-stranded template was achieved with minimal post-reaction purifications, which could be extremely important for mutation analysis and clinical diagnosis. A systematic study of the mechanisms and kinetics of sequencing reactions was also performed. The details of this analysis and directions for future improvements of the quality of sequencing are presented.