Thermal decomposition of methyl 2-azidopropionate studied by UV photoelectron spectroscopy and matrix isolation IR spectroscopy: heterocyclic intermediate vs imine formation.

Methyl 2-azidopropionate (N(3)CH(3)CHCOOCH(3), M2AP) has been synthesized and characterized by different spectroscopic methods, and the thermal decomposition of this molecule has been investigated by matrix isolation infrared (IR) spectroscopy and ultraviolet photoelectron spectroscopy (UVPES). Computational methods have been employed in the spectral simulation of both UVPES and matrix IR spectra and in the rationalization of the thermal decomposition results. M2AP presents a HOMO vertical ionization energy (VIE) of 9.60 ± 0.03 eV and contributions from all four lowest-energy conformations of this molecule are detected in the gas phase. Its thermal decomposition starts at ca. 400 °C and is complete at ca. 650 °C, yielding N(2), CO, CO(2), CH(3)CN, and CH(3)OH as the final decomposition products. Methyl formate (MF) and CH(4) are also found during the pyrolysis process. Analysis of the potential energy surface of the decomposition of M2AP indicates that M2AP decomposes preferentially into the corresponding imine (M2IP), through a 1,2-H shift synchronous with the N(2) elimination (Type 1 mechanism), requiring an activation energy of 160.8 kJ/mol. The imine further decomposes via two competitive routes: one accounting for CO, CH(3)OH, and CH(3)CN (ΔE(G3) = 260.2 kJ/mol) and another leading to CO(2), CH(4), and CH(3)CN (ΔE(G3) = 268.6 kJ/mol). A heterocyclic intermediate (Type 2 mechanism)-4-Me-5-oxazolidone-can also be formed from M2AP via H transfer from the remote O-CH(3) group, together with the N(2) elimination (ΔE(G3) = 260.2 kJ/mol). Finally, a third pathway which accounts for the formation of MF through an M2AP isomer is envisioned.

Expression of genes encoding extracellular matrix macromolecules and metalloproteinases in avian tibial dyschondroplasia.

Avian tibial dyschondroplasia (TD) is a skeletal disease characterized by disruption of endochondral bone formation. The aim of this study was to determine the expression of extracellular matrix (ECM) macromolecules and ECM-degrading enzymes [matrix metalloproteinases (MMPs)] in the growth plates of normal and TD-affected 3-week-old broiler chicks (Cobb strain). Protein levels were analyzed by immunoblotting and gelatin zymography and gene expression by polymerase chain reaction. Expression of genes encoding the ECM macromolecules (collagen types II, IX, X and XI; and aggrecan) was not altered in dyschondroplasia; however, there was down-regulation of genes encoding MMP-9, MMP-13, MMP-10 and MMP-11 in addition to reduced amounts of MMP-2 and MMP-13 proteins. In contrast, there was up-regulation of genes encoding MMP-7 and the vascular endothelial growth factor. These findings suggest that the accumulation of cartilage associated with the disease may be the result of decreased proteolysis due to the down-regulation of MMPs and not to an increased production of ECM macromolecules.

Allergic asthma in patients with common variable immunodeficiency.

BACKGROUND: Many patients with common variable immunodeficiency (CVID) have a clinical history suggestive of allergic respiratory disease. However, in such individuals, the prevalence of asthma and the role of atopy have not been well established. The objective of this study was to evaluate pulmonary function and identify asthma in patients with CVID. We also investigated the role of IgE as a trigger of asthma in these patients. METHODS: Sixty-two patients diagnosed with CVID underwent spirometry, as well as skin prick testing and in vitro determination of serum-specific IgE levels for aeroallergens, together with bronchial provocation with histamine and allergen. RESULTS: The most common alteration identified through spirometry was obstructive lung disease, which was observed in 29 (47.5%) of the 62 patients evaluated. Eighteen (29.0%) of the 62 patients had a clinical history suggestive of allergic asthma. By the end of the study, asthma had been diagnosed in nine (14.5%) patients and atopy had been identified in six (9.7%). In addition, allergic asthma had been diagnosed in four patients (6.5% of the sample as a whole; 22.2% of the 18 patients with a clinical history suggestive of the diagnosis). CONCLUSION: In this study, CVID patients testing negative for specific IgE antibodies and suspected of having allergic asthma presented a positive response to bronchial provocation tests with allergens. To our knowledge, this is the first such study. When CVID patients with a history suggestive of allergic asthma test negative on traditional tests, additional tests designed to identify allergic asthma might be conducted.

Cardosins: a new and efficient plant enzymatic tool to dissociate neuronal cells for the establishment of cell cultures.

In the present work, we examined the feasibility of using cardosins, plant aspartic-proteinases from Cynara cardunculus L., to isolate cells from rat embryonic brain. Using morphological and functional assays, we compared cell cultures obtained with cardosins with those prepared with a well-established trypsin protocol. Cardosins and trypsin dissociation produced cells with similar yield, viability, and GABA release in response to a depolarizing stimulus. However, cardosins-dissociated cells appeared to recover faster in culture, as assessed by the MTT-test and by the number and length of neurtites, suggesting that cardosins are less aggressive to neurons than trypsin. This feature might be helpful for research and medical purposes requiring fast manipulations of cells.

Comparação da secreção de citocinas (IL-4, IL-5, IL-6, IL-10) entre pacientes com nefropatia da IgA e deficiência de IgA / Comparison of the cytokine secretion (IL-4, IL-5, IL-6, IL-10) among patients with IgA nephropathy and IgA deficiency

Objetivo: A nefropatia primária da IgA (NIgA) e adeficiência de IgA (DIgA) constituem as formas maiscomuns de glomerulonefrite e de deficiência primáriade anticorpos, respectivamente, despertando interesseespecial o fato de ambas envolverem distúrbios contrastantes da produção da IgA. O objetivo deste trabalho foi comparar os níveis de citocinas possivelmente implicadas na produção da IgA (IL-4, IL-5, IL-6, IL-10) em pacientes com NIgA ou DIgA. Casuística e Métodos: Foram estudados 18 pacientes com NIgA (hematúria microscópica e proteinúria persistente ou intermitente e biópsia renal percutânea com depósito de IgA em mesângio glomerular detectado por imunofluorescência), sendo nove do gênero masculino e nove do feminino, com média de idade de 33,2 anos; 17 pacientes com DIgA (níveis séricos de IgA menores do que 7 mg/dL e níveis normais ou elevados de IgG e IgM), sendo 13 do gênero masculino e quatro do feminino, com média de idade de 25,5 anos; dez voluntários sadios (dois do gênero masculino e oito do feminino com média de idade de 30,7 anos). As citocinas foram quantificadas por método imunoenzimático em sobrenadante de cultura de PMBC após 48 horas de estímulo com fitohemaglutinina . Resultados: Foram observados: 1) níveis elevadosde IL-5 e de IL-10 e baixos de IL-6 em pacientes com NIgA em relação aos pacientes com DIgA e controlessadios; 2) níveis semelhantes de IL-4 em ambos gruposde pacientes e mais elevados na NIgA em comparaçãoaos controles sadios; 3) níveis similares de todasas citocinas testadas em pacientes com DIgA e controlessadios. Conclusões: Os níveis elevados de IL-5 encontrados na NIgA reforçam a importância desta citocina na síntese de IgA, cujos níveis séricos estão aumentados em aproximadamente 50 per cent dos casos; os níveis elevados de IL-4 e IL-5 encontrados nestes pacientes sugerem que estas duas citocinas possam estar envolvidas na glicosilação da IgA e seu conseqüente depósito em mesângio renal; os níveis elevados de IL-10 e baixos de IL-6 observados em pacientes com NIgA reforçam a hipótese de que a IL-10 esteja implicada na síntese da IgA em humanos e sugerem que esta citocina possa desempenhar um papel regulador sobre a produção deIL-6.

The effect of diethylamine on Stille alkylations with tetraalkylstannanes.

The addition of diethylamine to Stille alkylation reactions using stannanes improves yields by reducing beta-hydride elimination and reduction reactions, it also serves as a substitute for other additives such as Cu(I)I.

The first synthesis of (-)-asperpentyn and efficient syntheses of (+)-harveynone, (+)-epiepoformin and (-)-theobroxide.

A generally applicable strategy for the synthesis of a range of polyoxygenated cyclohexane natural products has been developed. The enantioselective syntheses of (-)-theobroxide, a polyoxygenated cyclohexane natural compound with potent growth inducing properties in potato microtubers has been achieved via a 1,2 O-silyl migration between trans-hydroxyl groups and a remote hydroxyl directed epoxidation of an enone derived from quinic acid. A thus derived alpha-iodoenone was subjected to Stille coupling with tetramethylstannane to afford the first title compound. A similar strategy enabled a route to the complete asymmetric synthesis of the acetylenic phytotoxin (+)-harveynone. By selective reduction of (-)-theobroxide, (+)-epiepoformin was also prepared in enantiopure form and similarly, stereoselective reduction of (+)-harveynone completed the first enantioselective synthesis of (-)-asperpentyn, another natural compound with antimicrobial activity.

Preparation of sucrose heptaesters unsubstituted at the C-1 hydroxy group of the fructose moiety via selective O-desilylation.

Selective O-desilylation of 6,1',6'-tri-O-tert-butyldiphenylsilyl-2,3,4,3',4'-penta-O-benzo ylsucrose with hydrofluoric acid in acetonitrile led to the 1'-O-tert-butyldiphenylsilyl derivative (96% yield), which was further perbenzoylated and deprotected at OH-1' with tetrabutylammonium fluoride (86%). An analogous sequence with the corresponding O-acetylated sucrose derivative and tetrabutylammonium fluoride as desilylating agent resulted in a lower yield of the C-1' hydroxy derivative.

Diarrhea and malabsorption in primary humoral immunodeficiency.

Patients with Humoral immunodeficiency syndromes frequently present recurrent infections, mainly of the digestive and respiratory tracts. This study carried out a clinical and laboratorial evaluation in 15 humoral immunodeficiency patients presenting chronic gastrointestinal symptoms. Out results emphasize the relevance of immunodeficiency syndromes in the differential diagnosis of chronic diarrhea.

Nephrotic syndrome associated with hepatointestinal schistosomiasis.

Schistosomal nephropathy has long been related to the hepatosplenic form of schistosomiasis. In the last few years, 24 patients with hepatointestinal schistosomiasis and the nephrotic syndrome were studied. Aiming at evaluating a possible etiologic participation of schistosomiasis in the development of the nephropathy, this group was comparatively studied with a group of 37 patients with idiopathic nephrotic syndrome. Both groups had a different distribution of the histologic lesions. In the group with schistosomiasis there was a statistically significant prevalence of proliferative mesangial glomerulonephritis (33.3%), whereas in the control group there was prevalence of membranous glomerulonephritis (32.4%). On immunofluorescence, IgM was positive in 94.4% of the patients with schistosomiasis versus 55.0% in the control group (P < 0.01). In the group with schistosomiasis, 8 patients evidenced mesangial proliferative glomerulonephritis and 5, membranoproliferative glomerulonephritis. In both histological types immunofluorescence showed IgM and C3 granular deposits in the glomeruli. The data in this study suggests that mesangial proliferative and membranoproliferative glomerulonephritis, with glomerular granular IgM and C3 deposits, represent the renal lesions of the schistosomiasis associated nephropathy.

Nephrotic syndrome associated with hepatointestinal schistosomiasis

Schistosomal nephropathy has long been related to the hepatosplenic form of schistosomiasis. In the last few years, 24 patients with hepatointestinal schistosomiasis and the nephrotic syndrome were studied. Aiming at evaluating a possible etiologic participation of schistosomiasis in the development of the nephropathy, this group was comparatively studied with a group of 37 patients with idiopathic nephrotic syndrome. Both groups had a different distribution of the histologic lesions. In the group with schistosomiasis there was a statistically significant prevalence of proliferative mesangial glomerulonephritis (33.3%), whereas in the control group there was prevalence of membranous glomerulonephritis (32.4%). On immunofluorescence, IgM was positive in 94.4% of the patients with schistosomiasis versus 55.0% in the control group (P < 0.01). In the group with schistosomiasis, 8 patients evidenced mesangial proliferative glomerulonephritis and 5, membranoproliferative glomerulonephritis. In both histological types immunofluorescence showed IgM and C3 granular deposits in the glomeruli. The data in this study suggests that mesangial proliferative and membranoproliferative glomerulonephritis, with glomerular granular IgM and C3 deposits, represent the renal lesions of the schistosomiasis associated nephropathy

Comparison of clinical significance and allergenic cross-reactivity of storage mites Blomia kulagini and Lepidoglyphus destructor in Sweden and Brazil.

Comparison of the clinical significance and allergenic cross-reactivity of Blomia kulagini (B. kulagini) and Lepidoglyphus destructor (L. destructor) was made on sera from Sweden and Brazil using the radio-allergo-sorbent test (RAST) and the RAST inhibition technique. RAST-positive sera were obtained from 53 allergic Swedish farmers and 31 allergic subjects from Brazil who were positive to B. kulagini and/or L. destructor. B. kulagini was shown to be a common cause of sensitization especially in Brazil. There was a fairly high correlation between positive RAST results to L. destructor and B. kulagini based on sera from both Sweden and Brazil. The highest RAST scores were found against L. destructor in Swedish sera and against B. kulagini in Brazilian sera. The RAST inhibition studies showed that the L. destructor extract was able to inhibit the B. kulagini system (a positive RAST to B. kulagini allergen disc) in Swedish but not in Brazilian sera. In contrast, the B. kulagini extract was only able to inhibit the L. destructor system in sera from Brazil and not in sera from Sweden. This study shows that results obtained with RAST inhibition are not entirely dependent on the overall specificity of the IgE antibodies in the patient's sera, since the more subtle specificity of the primarily sensitizing allergen will dominate. Thus, conclusions drawn regarding allergenic cross-reactivity are dependent on the populations tested, and conclusions on the existence or absence of cross-reactivity, e.g. between two species of mites may be contradictory.

Immune response to Blomia kulagini and Dermatophagoides pteronyssinus in Sweden and Brazil.

The immune responses to the non-pyroglyphid mite Blomia kulagini and the pyroglyphid mite Dermatophagoides pteronyssinus were compared in 440 Swedish farmers and 34 allergic subjects from Brazil using the radioallergosorbent test (RAST). Both B. kulagini and D. pteronyssinus were shown to be a common cause of sensitization, particularly in Brazil. The highest RAST scores were found against D. pteronyssinus in sera from both countries. Allergenic cross-reactivity between the two mites was studied by the RAST inhibition technique. Both B. kulagini and D. pteronyssinus possess their own unique allergens as well as allergens in common. Thus, besides mites belonging to the Dermatophagoides genus, other pyroglyphid and non-pyroglyphid mites in different countries should be taken into consideration before starting hyposensitization treatments.

[Polyglandular autoimmune type I syndrome with hypoparathyroidism, chronic mucocutaneous candidiasis and intestinal malabsorption]. / Síndrome poliglandular autoimmune do tipo I com hipoparatireoidismo, candidíase mucocutânea crônica e malabsorção intestinal.

The occurrence of chronic mucocutaneous candidiasis accompanying polyglandular autoimmune syndrome type I is reported in a female aged 13. Apart the candidiasis, since the age of 3, she had convulsions beginning at 6, cataract at 9, teeth abnormalities, and basal ganglia calcifications. Laboratory data confirmed the diagnosis of hypoparathyroidism. This picture was accompanied by intestinal malabsorption, leading to a state of progressive malnutrition, with intense hypoalbuminemia and anemia. Although the pathophysiology of malabsorption, in these cases, is still not clear, the therapeutic response to pancreatin, in the present case, suggested pancreatic insufficiency, reinforced by the normal d-xylose test and the small intestinal biopsy with inexpressive result.