Cruciferous phytoalexins: antiproliferative effects in T-Jurkat leukemic cells.

We tested antiproliferative activity of selected cruciferous phytoalexins including brassinin, 1-methoxybrassinin, (+/-)-spirobrassin, (+/-)-1-methoxyspirobrassinin and (+/-)-1-methoxyspirobrassinol, in leukemic Jurkat cell. The most effective of the tested phytoalexins was 1-methoxybrassinin with IC(50) 10 micromol l(-1). However, significant effect of all phytoalexines was also determined at concentration 1 micromol l(-1). In 1-methoxybrassinin-treated Jurkat cells, we found significant increase in the fraction of cells with a sub-G(0)/G(1) DNA content, which is considered to be a marker of cell death by apoptosis. Apoptosis was also confirmed by the annexin V staining. In summary, 1-methoxybrassinin exerted potent antiproliferative activity probably due to cell cycle arrest and apoptosis induction.

Phytoalexins from Thlaspi arvense, a wild crucifer resistant to virulent Leptosphaeria maculans: structures, syntheses and antifungal activity.

Phytoalexins are inducible chemical defenses produced by plants in response to diverse forms of stress, including microbial attack. Our search for phytoalexins from cruciferous plants resistant to economically important fungal diseases led us to examine stinkweed or pennycress (Thlaspi arvense), a potential source of disease resistance to blackleg. We have investigated phytoalexin production in leaves of T. arvense under abiotic (copper chloride) and biotic elicitation by Leptosphaeria maculans (Desm.) Ces. et de Not. [asexual stage Phoma lingam (Tode ex Fr.) Desm.], and report here two phytoalexins, wasalexin A and arvelexin (4-methoxyindolyl-3-acetonitrile), their syntheses and antifungal activity against isolates of P. lingam/L. maculans, as well as the isolation of isovitexin, a constitutive glycosyl flavonoid of stinkweed, having antioxidant properties but devoid of antifungal activity.

Synthesis, absolute configuration, and enantiomeric enrichment of a cruciferous oxindole phytoalexin, (S)-(-)-spirobrassinin, and its oxazoline analog.

Stereochemical studies of a cruciferous oxindole phytoalexin, (S)-(-)-spirobrassinin [(-)-4], and its oxazoline analogue, spirooxazoline (11), were carried out. Racemic spirobrassinin [(+/-)-4] was synthesized by SOCl(2)- or MsCl-mediated cyclization of dioxibrassinin [(+/-)-8]. Treatment of (3-hydroxyoxindol-3-yl)methylammonium chloride [(+/-)-9] with CSCl(2) and subsequent methylation of the obtained spirooxazolidinethione (+/-)-10 afforded spirooxazoline [(+/-)-11]. Enantioresolution of (+/-)-4 and (+/-)-11 was achieved by derivatization with (S)-(-)-1-phenylethyl isocyanate (12), chromatographic separation of diastereomeric amides 13, 14 or 15, 16, and their cleavage with CH(3)ONa. Absolute configuration of the stereogenic center in natural (S)-(-)-4 was derived from the exciton, calculated via CD methods, and unequivocally confirmed by X-ray crystallographic analyses of 1-[1'S,4'R-(-)-camphanoyl] derivatives [(-)-19 and (-)-20] of (+)- and (-)-4. Novel enantiomeric enrichment phenomena of 4 and 11 were discovered during their chromatographic separations under achiral HPLC conditions. Screening of antifungal activity against the fungus Bipolaris leersiae revealed no significant dependence of this activity on absolute configuration.

Enantiomeric excess of a cruciferous phytoalexin, spirobrassinin, and its enantiomeric enrichment in an achiral HPLC system.

Enantiomeric purity of a cruciferous phytoalexin, spirobrassinin (1), was determined by chiral HPLC analysis. The enantiomeric excesses of two natural spirobrassinin fractions separated by nonchiral chromatography were considerably different. A significant enantiomeric enrichment was observed during the nonchiral chromatographic separation of an artificial enantiomeric mixture of 1.

Restoration of the self-splicing activity of a defective group II intron by a small trans-acting RNA.

The yeast mitochondrial group II intron bI1 is self-splicing in vitro. We have introduced a deletion of hairpin C1 within the structural domain 1 that abolishes catalytic activity of the intron in the normal splicing reaction in cis, but does less severely affect a reaction in trans, the reopening of ligated exons. Since exon reopening is supposed to correspond to a reverse 3' cleavage this suggests that the deletion specifically blocks the first reaction step. The intron regains its activity to self-splice in cis by intermolecular complementation with a small RNA harbouring sequences lacking in the mutant intron. These results demonstrate the feasibility to reconstitute a functionally active structure of the truncated intron by intermolecular complementation in vitro. Furthermore, the data support the hypothesis that group II introns are predecessors of nuclear pre-mRNA introns and that the small nuclear RNAs of the spliceosome arose by segregation from the original intron.

[Radionuclide venography in occlusions of the inferior vena cava]. / Radionuklidová venografie pri uzáverech dolní duté zíly.

Based on 1234 examinations made by radionuclide venography the authors evaluated a group of 11 patients, where an occlusion of the vena cava was proved. In five instances ascension of thrombosis from the area of the pelvic veins was involved. in three instances compression by a tumour, twice the cause of occlusion was surgical ligature of the vena cava inferior. In one instance suppurative thrombosis developed as a result of spread of the infection from an intraabdominal abscess. Radionuclide venography provided evidence of a collateral circulation, as a rule a combination of several collateral routes was involved. Most frequently parietal collaterals in the abdominal aorta were present (9X), 4X paravertebral venous routes and only once anastomoses into the system of the azygos vein. In six patients anastomoses via the portal vein were found (cavoportal anastomoses). Based on their own experience, the authors evaluated the importance of radionuclide venography. Its advantage is the possible administration of the radiopharmaceutical preparation into the peripheral vein on the leg, the simple, safe procedure, the reproducibility and diagnostic yield during detection of high occlusions in the area of the vena cava inferior.

Use of radionuclides in the diagnosis of thromboembolism of venous origin: its potential and limitations. A review.

The review discusses the potential and limitations of radionuclide (RN) techniques of examination in diagnosing thromboembolic disease of venous origin. The advantages and drawbacks of perfusion pulmonary scintigraphy as the most commonly used method are weighed especially with a view to the diagnosis of pulmonary embolism (PE). The need for a combined examination including inhalation scintigraphy and chest X-ray is underlined. The criteria for interpreting results of RN techniques of examination in assessing the presence of PE are defined. Of the methods used in the diagnosis of venous thrombosis, the benefits and limitations of the fibrinogen uptake test (FUT) and radionuclide venography (RNV) are pointed out. When comparing RNV with X-ray phlebography, the authors found a low sensitivity in the crural area (54%) and, on the contrary, a 100% agreement in the areas of iliac veins and the vena cava inferior.

[Comparison of radionuclide venography with roentgen phlebography]. / Srovnání radionuklidové venografie s rtg-flebografií.

The authors evaluated a group of 78 patients where in addition to radionuclide venography (RNV) also X-ray phlebography was used (RTGF) within a time interval of not more than 72 hours. The results of 102 examinations were compared, 276 areas were correlated at six different sites. Agreement was recorded in 249 instances (90%), a false negative finding in 23 (8%) and a false positive finding in 4 (2%). Sensitivity was low in the area of the calf (55%), high in the femoral area, iliac area and in the area of the inferior vena cava (92-100%). The specificity was in all areas, incl. the calf, relatively high (94-100%). The investigation revealed the disadvantages of RNV--a low reliability in the area of the calf, the impossibility to detect small and parietal thrombi, the inability to assess the "activity and age" of the thrombus, the more difficult interpretation in insufficiency of venous perforators, and advantages of RNV--a great reliability at higher parts of the venous system and after administration of radiopharmaceutical preparations (RF) into peripheral veins, the possibility of simultaneous examination of pulmonary perfusion without further administration of RF, a low failure rate of intravenous administration of RF (less than 2%); RF do not irritate the venous endothelium and therefore thrombosis cannot develop; in case of paravenous escape of RF local inflammations do not develop, the radiation load is low, there is a small probability of allergic reactions, the method is non-invasive, it can be frequently repeated and used for the follow-up of treatment.

[Initial experience with autologous thrombocytes labeled with 111indium-oxine]. / První zkusenosti s autologními trombocyty znacenými 111indium-oxinem.

The authors elaborated their own modification of the separation and labelling of autologous thrombocytes by means of 111indium-oxine which can be implemented in Czechoslovak departments of nuclear medicine with standard equipment. A total of 123 separations and labellings were made and 85 administrations to patients. The effectiveness of labelling by the described method was 79.5 +/- 6.9%, the separation yield of thrombocytes with regard to complete blood 44.3 +/- 13.8%. The aggregating capacity of the labelled platelets assessed in vitro after ADP stimulation (adenosine diphosphate) was 39.5 +/- 10.1% difference in optic density of platelet rich and platelet poor plasma which is evidence of the preserved viability of thrombocytes. "Recovery" during the 120th minute after administration of normal suspensions was 62.2 +/- 17.9%, the survival time of labelled thrombocytes 8.2 +/- 0.74 days. In patients with idiopathic thrombocytopenic purpura the "recovery" was 49.4 +/- 18%, the survival period 2.9 +/- 1.8 days. In patients after transplantation of the kidney complicated by acute rejection there was an increased accumulation of labelled platelets in the area of the kidney (count rate index 2.32 +/- 0.45). In normally functioning transplanted kidneys the count rate index was 1.42 +/- 0.06. On their own material the authors demonstrate other possibilities of clinical application of scintigraphy by means of labelled autologous platelets (a method hitherto not described in the Ccezhoslovak literature) for the detection of intracardial and arterial thrombosis.

6,10,14-Trimethylpentadecan-2-one and 6,10,14-trimethyl-5-trans, 9-trans, 13-pentadecatrien-2-one from the androgenic glands of the male crab Carcinus maenas.

2 C18 isoprenoid ketones, hexahydrofarnesylacetone (1) and farnesylacetone (2) have been identified for the first time in lipid extracts from the androgenic glands of the male crab Carcinus maenas, using coupled gas chromatography-mass spectrometry. The 2 compounds prepared by synthesis, are biologically active, inhibiting the incorporation of 3H-leucine in Crustaceans ovaries subcultures.