La Chronique amusante / dir. G. Montferrier

1899/04/13 (A14,N15).

La Chronique amusante / dir. G. Montferrier

1899/07/13 (A14,N28).

Chemical indexes calculated for 8,11,13-trien-abietane diterpenoids isolated from Swartzia species

The disparity found in the molecular structures of compounds isolated from nine plants of the Swartzia genus indicates that the Swartzia species that furnished cassane diterpenoids and triterpenoidal saponins are more recent, since these metabolites have adopted the mevalonic acid route of formation, abandoning the shikimic acid/acetate route that produces the isoflavonoids found in the remaining species. Chemical indexes calculated from the molecular structure diversities of sixteen 8,11,13-trien-abietane diterpenoids isolated from Swartzia langsdorffii and S. arborescens indicate that S. arborescens is more recent than S. langsdorffii. The results suggest a more evolved position in Swartzia species of the section Possira.

Papel protetor do alelo G do polimorfismo no gene Interleucina 10 (-1082G/A) contra o desenvolvimento de pré-eclâmpsia

OBJETIVOS:Identificar a frequência do polimorfismo no gene IL-10, rs1800896 (-1082 A/G), em mulheres com pré-eclâmpsia (PE) e em mulheres do grupo controle e associar a presença deste polimorfismo com a proteção contra o desenvolvimento da PE.MÉTODOS:Estudo do tipo caso-controle, no qual foram selecionadas 54 mulheres com PE, classificadas de acordo com os critérios da National High Blood Pressure Education Program e 172 mulheres do grupo controle, com pelo menos duas gestações saudáveis. O polimorfismo proposto foi estudado utilizando-se a técnica de reação em cadeia da polimerase em tempo real (qPCR), com sondas de hidrólise. A análise estatística foi realizada utilizando-se o teste de associação do χ2. Odds ratio e seu intervalo de confiança de 95% foram usados para medir a força de associação entre o polimorfismo estudado e o desenvolvimento da PE.RESULTADOS:Foi observado aumento significativo da frequência do genótipo AG entre mulheres do grupo controle (85 versus 15% nas mulheres com PE). O alelo G é significativamente mais frequente entre as mulheres do grupo controle do que nas com PE (Teste χ2; p=0,01). Oodds ratio para as portadoras do alelo G foi de 2, 13, indicando que apresentam menor risco de desenvolver PE do que as não portadoras.CONCLUSÕES:Sugere-se associação entre a presença do alelo G do polimorfismo no geneIL-10, rs1800896 (-1082 A/G), e a proteção contra o desenvolvimento da PE. Mais estudos sobre a contribuição dessas variações e os mecanismos pelos quais afetam o risco de desenvolver PE ainda necessitam de ser realizadas.

Hoito- ja ajo-ohjeita : puuhiilikäyttöinen G. M. vaunut

kuv., 13 x 20 cm

Very High Energy Gamma-Rays emitting BL LAC's Population Study

Context: BL Lacs are the most numerous extragalactic objects which are detected in Very High Energy (VHE) gamma-rays band. They are a subclass of blazars. Large flux variability amplitude, sometimes happens in very short time scale, is a common characteristic of them. Significant optical polarization is another main characteristics of BL Lacs. BL Lacs' spectra have a continuous and featureless Spectral Energy Distribution (SED) which have two peaks. Among 1442 BL Lacs in the Roma-BZB catalogue, only 51 are detected in VHE gamma-rays band. BL Lacs are most numerous (more than 50% of 514 objects) objects among the sources that are detected above 10 GeV by FERMI-LAT. Therefore, many BL Lacs are expected to be discovered in VHE gamma-rays band. However, due to the limitation on current and near future technology of Imaging Air Cherenkov Telescope, astronomers are forced to predict whether an object emits VHE gamma-rays or not. Some VHE gamma-ray prediction methods are already introduced but still are not confirmed. Cross band correlations are the building blocks of introducing VHE gamma-rays prediction method. Aims: We will attempt to investigate cross band correlations between flux energy density, luminosity and spectral index of the sample. Also, we will check whether recently discovered MAGIC J2001+435 is a typical BL Lac. Methods: We select a sample of 42 TeV BL Lacs and collect 20 of their properties within five energy bands from literature and Tuorla blazar monitoring program database. All of the data are synchronized to be comparable to each other. Finally, we choose 55 pair of datasets for cross band correlations finding and investigating whether there is any correlation between each pair. For MAGIC J2001+435 we analyze the publicly available SWIFT-XRT data, and use the still unpublished VHE gamma-rays data from MAGIC collaboration. The results are compared to the other sources of the sample. Results: Low state luminosity of multiple detected VHE gamma-rays is strongly correlated luminosities in all other bands. However, the high state does not show such strong correlations. VHE gamma-rays single detected sources have similar behaviour to the low state of multiple detected ones. Finally, MAGIC J2001+435 is a typical TeV BL Lac. However, for some of the properties this source is located at the edge of the whole sample (e.g. in terms of X-rays flux). Keywords: BL Lac(s), Population study, Correlations finding, Multi wavelengths analysis, VHE gamma-rays, gamma-rays, X-rays, Optical, Radio

Effect of taxol on chromosome aberrations induced by gamma radiation or by doxorubicin in Chinese hamster ovary cells

Combined therapy with radiation and chemotherapy has being increasingly used in cancer treatment. The effect of combinations of taxol (0.08 mug/ml) with doxorubicin (DXR, 0.5 or 1.0 mug/ml) or gamma radiation (20 or 40 cGy) was examined in two different treatment schedules (pretreatment or simultaneous treatment) using Chinese hamster ovary (CHO) cells treated at the G2 phase of the cell cycle. The results showed that taxol did not have a radiosensitizing effect on the chromosomal aberrations induced by gamma radiation nor did it have a potentiating effect on the chromosomal aberrations induced by DXR in CHO cells treated in the G2 phase of the cell cycle

Effect of gamma irradiation on the behavioral properties of crotoxin

Crotoxin has been detoxified with gamma radiation in order to improve crotalic antiserum production. Nevertheless, present knowledge of the biological characteristics of irradiated crotoxin is insufficient to propose it as an immunizing agent. Crotoxin is known to increase the emotional state of rats and to decrease their exploratory behavior (Moreira EG, Nascimento N, Rosa GJM, Rogero JR and Vassilieff VS (1996) Brazilian Journal of Medical and Biological Research, 29: 629-632). Therefore, we decided 1) to evaluate the effects of crotoxin in the social interaction test, which has been widely used for the evaluation of anxiogenic drugs, and 2) to determine if irradiated crotoxin induces behavioral alterations similar to those of crotoxin in the social interaction, open-field and hole-board tests. Male Wistar rats (180-220 g) were used. Crotoxin (100, 250, and 500 µg/kg) was injected intraperitoneally 2 h before the social interaction test. Similarly, irradiated crotoxin (2000 Gy gamma radiation from a 60Co source) was administered at the doses of 100, 250, and 500 µg/kg for the hole-board test, and at the doses of 1000 and 2500 µg/kg for the open-field and social interaction tests. ANOVA complemented with the Dunnett test was used for statistical analysis (P<0.05). Crotoxin decreased the social interaction time (s) at the doses of 100, 250 and 500 µg/kg (means ± SEM) from 51.6 ± 4.4 to 32.6 ± 3.7, 28.0 ± 3.6 and 31.6 ± 4.4, respectively. Irradiated crotoxin did not induce behavioral alterations. These results indicate that 1) crotoxin may be an anxiogenic compound, and 2) in contrast to crotoxin, irradiated crotoxin was unable to induce behavioral alterations, which makes it a promising compound for the production of crotalic antiserum

Interferon gamma is a key cytokine in lung phase immunity to schistosomes but what is its precise role?

Vaccination of mice with radiation-attenuated cercariae of Schistosoma mansoni induces a high level of protection against challenge with normal larvae. The immune effector mechanism, which operates in the lungs, is a cell-mediated delayed-type hypersensitivity response and involves the formation of a tight focus of mononuclear cells around embolised larvae. CD4+ T cells with Th1 characteristics are a major component of the infiltrate. They secrete abundant interferon gamma (IFNg) upon antigen stimulation in vitro, whilst in vivo neutralisation of the cytokine results in 90% abrogation of immunity. IFNg can induce a large number of genes and an attempt has been made to identify the ones which are essential components of the effector mechanism. Inducible nitric oxide synthase (iNOS) is such a candidate and nitric oxide (NO) is produced by cultures of airway leucocytes from the lungs of vaccinated mice post-challenge. However, the continued resistance of mice with a disrupted iNOS gene indicates that NO has only a minor role in the protective response. Mice with a disrupted IFNg receptor gene have been used to dissect the role of the cytokine. After vaccination and challenge, CD4+ T cells from the pulmonary interstitium have reduced levels of ICAM-1 and LFA-1 expression, compared to wild-type animals, which coincides with a reduced cohesiveness of foci. However, immunity is not significantly impaired in mice with a disrupted ICAM-1 gene, and focus formation is normal. Similarly, a role has not been found for CD2/CD48 interactions in cell aggregation. Possible IFNg-inducible molecules yet to be fully investigated include other ligand-receptor pairs, chemokines, and tumour necrosis factor a.

A chromatographic method for the production of a human immunoglobulin G solution for intravenous use

Immunoglobulin G (IgG) of excellent quality for intravenous use was obtained from the cryosupernatant of human plasma by a chromatographic method based on a mixture of ion-exchange, DEAE-Sepharose FF and arginine Sepharose 4B affinity chromatography and a final purification step by Sephacryl S-300 HR gel filtration. The yield of 10 experimental batches produced was 3.5 g IgG per liter of plasma. A solvent/detergent combination of 1% Tri (n-butyl) phosphate and 1% Triton X-100 was used to inactivate lipid-coated viruses. Analysis of the final product (5% liquid IgG) based on the mean for 10 batches showed 94% monomers, 5.5% dimers and 0.5% polymers and aggregates. Anticomplementary activity was 0.3 CH50/mg IgG and prekallikrein activator levels were less than 5 IU/ml. Stability at 37ºC for 30 days in the liquid state was satisfactory. IgG was stored in flasks (2.5 g/flask) at 4 to 8ºC. All the characteristics of the product were consistent with the requirements of the 1997 Pharmacopée Européenne.

Administration of interferon-g to pregnant rats reverses the depressed adjuvant-induced arthritis of their chronically Trypanosoma cruzi-infected offspring

We demonstrated that administration of interferon gamma (IFN-g) to the inbred "l" strain of pregnant rats conferred partial resistance on their offspring to challenge with Trypanosoma cruzi. We now examine if this intervention also modifies the reportedly immunodepressed cellular responses which occur during chronic infection. Offspring were born to mothers undergoing one of the following procedures during gestation: subcutaneous injections of recombinant rat IFN-g, 50,000 IU/rat, five times/week for 3 weeks, which was started on the day of mating (IFN-Mo); infection with 106 trypomastigotes of T. cruzi at 7, 14, and 21 days after mating plus IFN-g treatment as given to the former group (TcIFN-Mo); the same protocol except that physiological saline was injected instead of IFN-g (Tc-Mo); injection of physiological saline only (control-Mo). All offspring groups (N = 8-10/group) were infected at weaning and were assessed 90 days later for their adjuvant-induced arthritic response or levels of major T cell subsets in spleen and lymph nodes. TcIFN-Mo and IFN-Mo offspring showed a reestablished arthritic response, which remained within the range seen in controls. Immunolabeling studies on parallel groups of 90-day-infected offspring showed that the inverse CD4/CD8 cell ratio that is usually seen in lymphoid organs from these chronically infected rats (median 0.61) appeared to have recovered in the TcIFN-Mo and IFN-Mo groups (median 1.66 and 1.78, respectively) and was not different from uninfected controls (1.96). These studies indicate that early stimulation with IFN-g is able to reverse the immunosuppressive state that is usually present during the chronic period of the experimental infection.

Serum cytokine levels in autoimmune and non-autoimmune hyperthyroid states

Although the role of interleukin-2 (IL-2) and interferon gamma (gIFN) is still poorly understood in hyperthyroid diseases, it is reasonable to assume that these cytokines may be present at higher levels in Graves' disease (GD) than in other primarily non-autoimmune thyroid diseases. In order to look for an easy method to distinguish GD from primarily non-autoimmune causes of hyperthyroidism, we compared 13 healthy individuals with 21 treated and untreated hyperthyroid GD patients and with 19 patients with hyperthyroidism due to other etiologies: 7 cases of multinodular goiter, 5 cases of excessive hormone replacement and 7 cases of amiodarone-associated hyperthyroidism. All patients presented low TSH levels and a dubious clinical thyroid state. We found a good correlation between TSH and serum IL-2 levels (r = 0.56; P<0.01). Serum IL-2 (P<0.01) and gIFN (P<0.01) levels were lower in the hyperthyroid group of patients than in control subjects, suggesting a depressed TH1 pattern in the T-cell subset of hyperthyroid patients. GD had normal IL-2 levels, while patients with other forms of thyrotoxicosis presented decreased IL-2 levels (P<0.05). There was no difference between treated and untreated GD patients. We suggest that the direct measurement of serum IL-2 level may help to confirm hyperthyroidism caused by GD.

The Agamma-195 (C->G) mutation in hereditary persistence of fetal hemoglobin is not associated with activation of a reporter gene in vitro

Hereditary persistence of fetal hemoglobin is an uncommon, benign disorder in which the expression of gamma-globin genes persists into adult life. Several point mutations have been associated with the increased gamma-globin gene promoter activity. We evaluated the -195 (C->G) mutation by a functional in vitro assay based on the luciferase reporter gene system. The results indicated that the increased promoter activity observed in vivo could not be reproduced in vitro under the conditions employed, suggesting that other factors may be involved in the overexpression of the gamma-globin gene containing the -195 (C->G) mutation. Furthermore, this is the first time that the -195 (C->G) mutation of the Agamma-globin gene has been evaluated by in vitro gene expression.

Effects of 60Co gamma radiation on crotamine

Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide (pI 10.3) from Crotalus durissus terrificus venom composed of 42 amino acid residues. It induces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. The objective of the present study was to carry out a biochemical study and a toxic activity assay on native and irradiated crotamine. Crotamine was purified from C.d. terrificus venom by Sephadex G-100 gel filtration followed by ion-exchange chromatography, and irradiated at 2 mg/ml in 0.15 M NaCl with 2.0 kGy gamma radiation emitted by a 60Co source. The native and irradiated toxins were evaluated in terms of structure and toxic activity (LD50). Irradiation did not change the protein concentration, the electrophoretic profile or the primary structure of the protein although differences were shown by spectroscopic techniques. Gamma radiation reduced crotamine toxicity by 48.3%, but did not eliminate it.

Kinetics of TNF-alpha and IFN-gamma mRNA expression in islets and spleen of NOD mice

Insulin-dependent diabetes mellitus is caused by autoimmune destruction of pancreatic ß cells. Non-obese diabetic (NOD) mice spontaneously develop diabetes similar to the human disease. Cytokines produced by islet-infiltrating mononuclear cells may be directly cytotoxic and can be involved in islet destruction coordinated by CD4+ and CD8+ cells. We utilized a semiquantitative RT-PCR assay to analyze in vitro the mRNA expression of TNF-alpha and IFN-gamma cytokine genes in isolated islets (N = 100) and spleen cells (5 x 10(5) cells) from female NOD mice during the development of diabetes and from female CBA-j mice as a related control strain that does not develop diabetes. Cytokine mRNAs were measured at 2, 4, 8, 14 and 28 weeks of age from the onset of insulitis to the development of overt diabetes. An increase in IFN-gamma expression in islets was observed for females aged 28 weeks (149 ± 29 arbitrary units (AU), P<0.05, Student t-test) with advanced destructive insulitis when compared with CBA-j mice, while TNF-alpha was expressed in both NOD and CBA-j female islets at the same level at all ages studied. In contrast, TNF-alpha in spleen was expressed at higher levels in NOD females at 14 weeks (99 ± 8 AU, P<0.05) and 28 weeks (144 ± 17 AU, P<0.05) of age when compared to CBA-j mice. The data suggest that IFN-gamma and TNF-alpha expression in pancreatic islets of female NOD mice is associated with ß cell destruction and overt diabetes.