Photodissociation and formation of an ion-pair in CH2 FCl (HCFC-31).

Although CH2 FCl (HCFC-31) recently became of great atmospheric importance, studies concerning its excited states are almost nonexistent. Several excited singlet states were studied (valence nσ* and Rydberg n3s, n3p, σ3s, and σ3p) through highly correlated multireference configuration interaction with singles and doubles, including extensivity correction. Comparison with the states of CH3 Cl indicates a strong influence of the F atom. Potential energy curves suggest formation of an electrostatically bound complex that relaxes to a hydrogen-bonded contact ion-pair (HBCIP) which can decay yielding CH2 F + Cl or to the ground state minimum of CH2 FCl. The HBCIP has a dipole moment of 9.57 D, a CI wavefunction described as 0.65ionic + 0.20biradical and it is strongly bonded by 4.72 eV. Its H bond has characteristics of moderate and strong H bonds. The simulated absorption spectrum confirms the nσ* assignment for the first and suggests the n3s + n3pσ assignment for the second band.

Superabsorbent Hydrogels Based to Polyacrylamide/Cashew Tree Gum for the Controlled Release of Water and Plant Nutrients.

Agricultural production is influenced by the water content in the soil and availability of fertilizers. Thus, superabsorbent hydrogels, based on polyacrylamide, natural cashew tree gum (CG) and potassium hydrogen phosphate (PHP), as fertilizer and water releaser were developed. The structure, morphology, thermal stability and chemical composition of samples of polyacrylamide and cashew tree gum hydrogels with the presence of fertilizer (HCGP) and without fertilizer (HCG) were investigated, using X-ray diffractometry (XRD), Fourier Transformed Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA/DTG) and Energy Dispersive Spectroscopy (EDS). Swelling/reswelling tests, textural analysis, effect of pH, release of nutrients and kinetics were determined; the ecotoxicity of the hydrogels was investigated by the Artemia salina test. The results showed that PHP incorporation in the hydrogel favored the crosslinking of chains. This increased the thermal stability in HCGP but decreased the hardness and adhesion properties. The HCGP demonstrated good swelling capacity (~15,000 times) and an excellent potential for reuse after fifty-five consecutive cycles. The swelling was favored in an alkaline pH due to the ionization of hydrophilic groups. The sustained release of phosphorus in HCGP was described by the Korsmeyer-Peppas model, and Fickian diffusion is the main fertilizer release mechanism. Finally, the hydrogels do not demonstrate toxicity, and HCGP has potential for application in agriculture.

Synthesis and Characterization of Cassava Gum Hydrogel Associated with Chlorhexidine and Evaluation of Release and Antimicrobial Activity.

Hydrogels from natural sources are attracting increasing interest due to their ability to protect biologically active molecules. Starch extracted from cassava tubers is a promising material for synthesizing these hydrogels. Copolymerization of cassava gum and incorporation of chlorhexidine digluconate (CLX) into the hydrogels is confirmed by changes in the crystallographic profile, as observed through X-ray diffraction, and a shift in the 1000 cm-1 band in the Fourier-transform infrared spectroscopy spectrum. The differential scanning calorimetry reveals changes in the decomposition temperature of the synthesized hydrogels related to CLX volatility. Micrographs illustrate the material's porosity. Release tests indicate a constant linear release over 72 h, while antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans is satisfactory, with 100% effectiveness from 0.5% CLX and the formation of inhibition halos. Toxicity and biocompatibility studies show no cytotoxicity. The continuous release of chlorhexidine is promising for components of biomedical implants and applications as it can ensure antimicrobial action according to specific therapeutic needs.

Mutation of tumor suppressor gene Men1 acutely enhances proliferation of pancreatic islet cells.

Multiple endocrine neoplasia type 1 (MEN1), an inherited tumor syndrome affecting endocrine organs including pancreatic islets, results from mutation of the tumor suppressor gene Men1 that encodes protein menin. Although menin is known to be involved in regulating cell proliferation in vitro, it is not clear how menin regulates cell cycle and whether mutation of Men1 acutely promotes pancreatic islet cell proliferation in vivo. Here we show that excision of the floxed Men1 in mouse embryonic fibroblasts (MEF) accelerates G(0)/G(1) to S phase entry. This accelerated S-phase entry is accompanied by increased cyclin-dependent kinase 2 (CDK2) activity as well as decreased expression of CDK inhibitors p18(Ink4c) and p27(Kip1). Moreover, Men1 excision results in decreased expression of p18(Ink4c) and p27(Kip1) in the pancreas. Furthermore, complementation of menin-null cells with wild-type menin represses S-phase entry. To extend the role of menin in repressing cell cycle in cultured cells to in vivo pancreatic islets, we generated a system in which floxed Men1 alleles can be excised in a temporally controllable manner. As early as 7 days following Men1 excision, pancreatic islet cells display increased proliferation, leading to detectable enlargement of pancreatic islets 14 days after Men1 excision. These observations are consistent with the notion that an acute effect of Men1 mutation is accelerated S-phase entry and enhanced cell proliferation in pancreatic islets. Together, these results suggest a molecular mechanism whereby menin suppresses MEN1 tumorigenesis at least partly through repression of G(0)/G(1) to S transition.

Energetics of lizard embryos are not canalized by thermal acclimation.

In some species of ectotherms, temperature has little or no effect on the amount of energy expended during embryonic development. This phenomenon can result from either of two mechanisms: (1) a shorter incubation period at higher temperatures, which offsets the expected increase in metabolic rate, or (2) a compensatory decrease in the rate at which embryos expend energy for maintenance. To distinguish the relative importance of these two mechanisms, we quantified the acute and chronic effects of temperature on embryonic metabolism in the eastern fence lizard (Sceloporus undulatus). First, we measured metabolic rates of individual embryos at 27 degrees, 31 degrees, and 34 degrees C. Second, we examined the capacity for thermal acclimation by measuring the metabolic rates of embryos at 30 degrees C, after a period of incubation at either 28 degrees or 32 degrees C. As with adult reptiles, the metabolic rates of embryos increased with an acute increase in temperature; the Q(10) of metabolic rate from 27 degrees to 34 degrees C was 2.1 (+/-0.2). No evidence of thermal acclimation was observed either early or late in development. In S. undulatus, a shorter incubation period at higher temperatures appears to play the primary role in canalizing the energy budget of an embryo, but a reduction in the cost of growth could play a secondary role.

Functional interaction between tumor suppressor menin and activator of S-phase kinase.

Multiple endocrine neoplasia type I (MEN1), a hereditary tumor syndrome, is characterized by the development of tumors in multiple endocrine organs. The gene mutated in MEN1 patients, Men1, encodes a tumor suppressor, menin. Overexpression of menin leads to inhibition of Ras-transformed cells. However, it is unclear whether menin is essential for repression of cell proliferation, and if it is, how it inhibits cell proliferation. Here, we show that targeted disruption of the Men1 gene leads to enhanced cell proliferation, whereas complementation of menin-null cells with menin reduces cell proliferation. Moreover, menin interacts with activator of S-phase kinase (ASK), a component of the Cdc7/ASK kinase complex that is crucial for cell proliferation, but does not appear to alter Cdc7 kinase activity in in vitro kinase assays. We identify the COOH terminus of menin as the domain that mediates the specific interaction with ASK. Notably, wild-type menin completely represses ASK-induced cell proliferation, although it does not obviously affect the steady-state cell cycle profile of ASK-infected cells. Interestingly, disease-related COOH-terminal menin mutants that do not interact with ASK completely fail to repress ASK-induced cell proliferation. Together, these findings demonstrate a functional link between menin and ASK in the regulation of cell proliferation.

Menin associates with FANCD2, a protein involved in repair of DNA damage.

Multiple endocrine neoplasia type I (MEN1) is an inherited tumor syndrome characterized by tumors in multiple endocrine organs including the parathyroids, pancreatic islets, and the pituitary. The gene mutated in MEN1 patients, Men1, encodes a protein of 610 amino acid residues, menin, and mutations in the Men1 gene lead to the MEN1 syndrome. Although the chromosomal instability in the peripheral lymphocytes from the MEN1 patients has been reported previously, it is not clear whether menin is involved in repair of DNA damage. Here we show that menin specifically interacts with FANCD2, a protein encoded by a gene involved in DNA repair and mutated in patients with an inherited cancer-prone syndrome, Fanconi anemia. The interaction between menin and FANCD2 is enhanced by gamma-irradiation. Moreover, loss of menin expression in mouse embryonic fibroblasts leads to increased sensitivity to DNA damage. Furthermore, menin is localized to chromatin and nuclear matrix, and the association with nuclear matrix is enhanced by gamma-irradiation. Together, these results suggest that menin plays a critical role in repair of DNA damage in concert with FANCD2.

Tumor suppressor menin regulates expression of insulin-like growth factor binding protein 2.

Multiple endocrine neoplasia type I (MEN1) is an inherited tumor syndrome characterized by development of tumors in multiple endocrine organs. The gene mutated in MEN1 patients, Men1, encodes a nuclear protein, menin. Menin interacts with several transcription factors and inhibits their activities. However, it is unclear whether menin is essential for the repression of the expression of endogenous genes. Here, using menin-null cells, we show that menin is essential for repression of the endogenous IGFBP-2, a gene that can regulate cell proliferation. Additionally, complementation of menin-null cells with wild-type menin, but not with a MEN1 disease-related point mutant, restores the function of menin in repressing IGFBP-2. Consistent with this, the promoter of IGFBP-2 is repressed by wild-type menin, but not by a MEN1-related point mutant. Menin also alters the structure of the chromatin surrounding the promoter of the IGFBP-2 gene, as demonstrated by the deoxyribonuclease I hypersensitivity assay. Furthermore, nuclear localization signals in menin are crucial for repressing the expression of IGFBP-2. Together, these results suggest that menin regulates the expression of the endogenous IGFBP-2 gene at least in part through the promoter of IGFBP-2.

Menin-mediated caspase 8 expression in suppressing multiple endocrine neoplasia type 1.

Multiple endocrine neoplasia type 1 (MEN1) is a familial tumor syndrome linked to mutation of the MEN1 gene, which encodes a tumor suppressor, menin. We previously reported that menin up-regulates the caspase 8 expression and promotes TNF-alpha-induced apoptosis. However, it remains unclear how menin up-regulates caspase 8 expression and whether menin-mediated caspase 8 expression plays a role in repressing MEN1 development. Here we show that menin binds the 5'-untranslated region (5'-UTR) of the Caspase 8 locus in vivo and activates transcription of a reporter gene through the 5'-UTR. Menin directly binds the 5'-UTR in a sequence-independent manner in vitro. Moreover, Men1 ablation in cells reduces acetylation of histones H3 and H4 at the 5'-UTR of the caspase 8 locus bound by menin in vivo. Notably, the MEN1-derived menin point mutants lose their ability to bind the caspase 8 locus and fail to induce caspase 8 expression and TNF-alpha-mediated apoptosis. Consistent with these observations, the expression level of caspase 8 is markedly reduced in insulinomas from Men1(+/-) mice. Together, our results indicate that menin enhances the caspase 8 expression by binding the caspase 8 locus, and suggest that menin suppresses MEN1 tumorigenesis, at least in part, by up-regulating caspase 8 expression.

Cdx4 and menin co-regulate Hoxa9 expression in hematopoietic cells.

BACKGROUND: Transcription factor Cdx4 and transcriptional coregulator menin are essential for Hoxa9 expression and normal hematopoiesis. However, the precise mechanism underlying Hoxa9 regulation is not clear. METHODS AND FINDINGS: Here, we show that the expression level of Hoxa9 is correlated with the location of increased trimethylated histone 3 lysine 4 (H3K4M3). The active and repressive histone modifications co-exist along the Hoxa9 regulatory region. We further demonstrate that both Cdx4 and menin bind to the same regulatory region at the Hoxa9 locus in vivo, and co-activate the reporter gene driven by the Hoxa9 cis-elements that contain Cdx4 binding sites. Ablation of menin abrogates Cdx4 access to the chromatin target and significantly reduces both active and repressive histone H3 modifications in the Hoxa9 locus. CONCLUSION: These results suggest a functional link among Cdx4, menin and histone modifications in Hoxa9 regulation in hematopoietic cells.

Prevalência de esteatose hepática e consumo de álcool em participantes do Projeto Atividade Física na Vila / Prevalence of nonalcoholic fatty liver disease and alcoholism in the participants of the Physical Activity in Community Project / Prevalencia de esteatosis hepática y consumo de alcohol en participantes del Projeycto Actividad Física en la Vila

A esteatose hepática é um achado cada vez mais frequente em exames de rastreamento por estudo de imagem. Tem sido descrita associação entre esteatose, obesidade, resistência à insulina e síndrome metabólica (SM). Também parece existir sinergismo entre esteatose hepática, álcool e fibrose hepática. O objetivo foi descrever a prevalência de esteatose e de etilismo nos participantes do Projeto "Atividade Física na Vila" e avaliar sua associação com a presença de obesidade e obesidade visceral. Foi realizada ultrassonografia abdominal em 69 participantes, 53,02±1,26 anos, sendo avaliados a presença e o grau de esteatose e as medidas da gordura subcutânea e visceral (GV). Foram excluídos os pacientes com hepatite viral e com etilismo significativo na anamnese ou após teste AUDIT. Após análise inicial, 60 pacientes foram avaliados quanto aos dados antropométricos e divididos em 2 grupos: com e sem esteatose. A prevalência de etilismo foi de 8,7%. A esteatose hepática foi observada em 37% dos pacientes sendo a maioria classificada como leve e moderada (91%). O grupo com esteatose apresentou aumento significativo de IMC (34,±8,7 versus 29,8±6,5kg/m2), cintura abdominal (102,6±12,7 versus 95,3±12,3cm), peso (85,8±18,7 versus 74,5±17,7kg) e GV (47,9±10,5 versus 36,0±12,7mm). A esteatose hepática é comum em obesos, especialmente naqueles com obesidade visceral. Sabemos que o álcool e a obesidade visceral podem estar envolvidos em seu mecanismo fisiopatológico. Por isso, os pacientes com esteatose hepática e consumo excessivo de álcool podem apresentar maior chance de evoluir desfavoravelmente para a cirrose e insuficiência hepática.

Screening image studies have shown that the frequency of hepatic steatosis findings has been progressivly increasing. The risk of developing NAFLD has been described and associated with obesity, insulin resistance and metabolic syndrome. There seems to be a correlation between NAFLD, alcohol e hepatic fibrosis. Our objective was to describe the prevalence of NAFLD and alcoholism in the participants of the of the Physical Activity in Community Project and to evaluate the associations between hepatic steatosis and presence of obesity and visceral obesity. Abdominal ultrasound was performed in 69 patients, 53.02±1.26 years old, looking for the presence and for the degree of fatty liver as well as subcutaneous and visceral fat. Patients with viral hepatitis and significant alcoholism were excluded after the AUDIT test. After this analysis, 60 patients were evaluated according to their anthropometrics data and were allocated into two groups: with and without fatty liver disease. The prevalence of alcoholism was 8.7%. Thirty seven percent of the patients showed up with NAFLD and were considered low to moderate risk (91%). The NAFLD showed a significant rise in the body mass index (34.1±8.7 versus 29.8±6.5kg/m2), waist circumference (102,6±12,7 versus 95.3±12.3cm), overall weight, (85,8±18,7 versus 74,5± 17.7kg), and visceral fat (47.9±10.5 versus 36.0±12.7mm). Hepatic steatosis is common in obese, especially in those with visceral obesity. We know that alcohol and visceral obesity are involved in the physiopathologic process of hepatic steatosis. For this reason, patients with Hepatic steatosis and excessive alcohol consumption may be at greater risk for Cirrhossis and hepatic insufficiency.

La esteatosis hepática es un descubrimiento cada vez más frecuente en exámenes de rastreamento por estudio de imágenes. Ha sido descripta asociación entre esteatosis, obesidad, resistencia a la insulina y síndrome metabólica (SM) .También parece existir sinergismo entre esteatosis hepática, alcohol y fibrosis hepática. El objetivo ha sido de describir la prevalencia de esteatosis hepática y de etilismo en los participantes del Proyecto Actividad Física en Vila y evaluar su asociación con la presencia de obesidad y obesidad visceral. Ha sido realizada ultrasonido abdominal en 69 participantes, 53,02±1,26 años, siendo evaluado la presencia y el grado de esteatosis y las medidas de grasa subcutánea y visceral (GV). Han sido excluidos los pacientes con la hepatitis viral y con etilismo significativo en las anamnesis o después del teste AUDIT. Después del análisis inicial, 60 pacientes se evaluaron cuanto a los datos antropométricos y divididos en 2 grupos: con y sin esteatosis. La prevalencia de etilismo ha sido de 8,7%.La esteatosis hepática ha sido observada en 37% de los pacientes siendo la mayoría clasificada como leve y moderada (91%). El grupo con esteatosis ha presentado aumento significativo de IMC (34,±8,7 x 29,8±6,5Kg/m2), cintura abdominal (102,6±12,7 x 95,3±12,3cm) peso (85,8±18,7 x 74,5±17,7 Kg) e GV (47,9±10,5 x 36,0±12,7 mm). La esteatosis hepática es común en obesos, especialmente en aquellos con obesidad visceral. Sabemos que el alcohol y la obesidad visceral pueden estar envueltos en su mecanismo fisiopatológico. Por eso, los pacientes con esteatosis hepática y consumo excesivo de alcohol pueden presentar mayor chance de evolucionar desfavorablemente para la cirrosis y insuficiencia hepáticas.

The tumor suppressor menin regulates hematopoiesis and myeloid transformation by influencing Hox gene expression.

Menin is the product of the tumor suppressor gene Men1 that is mutated in the inherited tumor syndrome multiple endocrine neoplasia type 1 (MEN1). Menin has been shown to interact with SET-1 domain-containing histone 3 lysine 4 (H3K4) methyltransferases including mixed lineage leukemia proteins to regulate homeobox (Hox) gene expression in vitro. Using conditional Men1 knockout mice, we have investigated the requirement for menin in hematopoiesis and myeloid transformation. Men1 excision causes reduction of Hoxa9 expression, colony formation by hematopoietic progenitors, and the peripheral white blood cell count. Menin directly activates Hoxa9 expression, at least in part, by binding to the Hoxa9 locus, facilitating methylation of H3K4, and recruiting the methylated H3K4 binding protein chd1 to the locus. Consistent with signaling downstream of menin, ectopic expression of both Hoxa9 and Meis1 rescues colony formation defects in Men1-excised bone marrow. Moreover, Men1 excision also suppresses proliferation of leukemogenic mixed lineage leukemia-AF9 fusion-protein-transformed myeloid cells and Hoxa9 expression. These studies uncover an important role for menin in both normal hematopoiesis and myeloid transformation and provide a mechanistic understanding of menin's function in these processes that may be used for therapy.

Menin induces apoptosis in murine embryonic fibroblasts.

Multiple endocrine neoplasia type I (MEN1) is a hereditary tumor syndrome characterized by multiple endocrine and occasionally non-endocrine tumors. The tumor suppressor gene Men1, which is frequently mutated in MEN1 patients, encodes the nuclear protein menin. Although many tumor suppressor genes are involved in the regulation of apoptosis, it is unclear whether menin facilitates apoptosis. Here we show that ectopic overexpression of menin via adenoviruses induces apoptosis in murine embryonic fibroblasts. The induction of apoptosis depends on Bax and Bak, two proapoptotic proteins. Moreover, loss of menin expression compromises apoptosis induced by UV irradiation and tumor necrosis factor-alpha (TNF-alpha), whereas complementation of menin-null cells with menin restores sensitivity to UV- and TNF-alpha-induced apoptosis. Interestingly, loss of menin reduces the expression of procaspase 8, a critical protease that is essential for apoptosis induced by death-related receptors, whereas complementation of the menin-null cells up-regulates the expression of procaspase 8. Furthermore, complementation of menin-null cells with menin increases the activation of caspase 8 in response to TNF-alpha treatment. These results suggest a proapoptotic function for menin that may be important in suppressing the development of MEN1.

Direct binding of DNA by tumor suppressor menin.

Menin is a tumor suppressor that is mutated in patients with multiple endocrine neoplasia type I (MEN1), an inherited tumor-prone syndrome. Because there is no obvious conserved structural domain in menin that suggests a biochemical function, little is known as to how menin suppresses tumorigenesis. Although menin interacts with a variety of nuclear proteins including transcription factors, it is unknown whether menin itself can directly bind DNA. Here we show that menin directly binds to double-stranded DNA. It also binds a variety of DNA structures, including Y-structures, branched structures, and 4-way junction structures. The COOH terminus of menin mediates binding to DNA, but MEN1 disease-derived mutations in the COOH terminus abolish the ability of menin to bind DNA. Importantly, these MEN1 disease-related menin mutants also fail to repress cell proliferation as well as cell cycle progression at the G2/M phase. Furthermore, detailed mutagenesis studies indicate that positively charged residues in two nuclear localization signals mediate direct DNA binding as well as repression of cell proliferation. Collectively, these results demonstrate, for the first time, a novel biochemical activity of menin, binding to DNA, and link its DNA binding to the regulation of cell proliferation.

Doença hepática gordurosa não-alcoólica: associação com síndrome metabólica e fatores de risco cardiovascular / Nonalcoholic fatty liver disease: association with metabolic syndrome and cardiovascular risk factors

Fundamentos: A doença hepática gordurosa não-alcoólica (DHGNA)) é uma condição comum, que ocorre em indivíduos sem ingestão etílica significativa. Tem sido descrita associação entre obesidade, resistência à insulina, síndrome metabólica (SM e a DHDNA. Objetivo: Descrever a prevalência de DHGNA e sua associação com a SM e os fatores de risco cardiovasculat nos participantes do projeto "Atividade Física na Vila". Métodos: foi realizada ultra-sonografia abdominal em 69 participantes, 53,02 mais ou menos 1,26 anos, sendo avaliada a presença e o grau de esteanose e as medidas da gordura subcutânea e visceral (GV). Após exclusão de hepatite viral e etilismo, 60 pacientes foram avaliados quanto aos dados antropométricos, à presença de SM e aos fatores de risco cardiovascular, estratificados em dois grupos: com e sem DHGNA. Resultados: A DHGNA foi observada em 37 por cento, sendo a maioria classificada como leve e moderada (91 por cento). O grupo com DHGNA apresentou aumento significativo de IMC (34 mais ou menos 8,7kg/m² x 29,8 mais ou menos 6,5kg/m²), cintura abdominal (102,6 mais ou menos 12,7cm x 95,3 mais ou menos 12,3cm), peso (85,8kg mais ou menos 18,7 x 74,5 mais ou menos 17,7kg), pressão arterial diastólica...