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1.
Angew Chem Int Ed Engl ; 63(24): e202403119, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38604974

RESUMO

Nickel-catalyzed cross-electrophile coupling reactions of two aliphatic alcohol derivatives remain a challenge. Herein, we report a nickel-catalyzed reductive methylation reaction of aliphatic mesylates with methyl tosylate. This reaction provides straightforward access to compounds bearing aliphatic methyl groups from alkyl alcohol derivatives. Isotopically labelled substrates and reagents can be employed in the reaction to provide perdeuterated and 13C-labelled products. This transformation can be achieved by employing stoichiometric Mn reductant or electrochemically. Additionally, mechanistic experiments show that alkyl iodides are key intermediates in the transformation which undergo a stereoablative reaction via radical intermediates.

2.
ACS Catal ; 13(8): 5472-5481, 2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37123596

RESUMO

Understanding mechanistic details of the nickel-catalyzed coupling reactions of Csp3 alcohol derivatives is key to developing selective reactions of this widely prevalent functional group. In this manuscript, we utilize a combination of experimental data and DFT studies to define the key intermediates, stereochemical outcome, and competing pathways of a nickel-catalyzed cross-electrophile coupling reaction of 1,3-dimesylates. Stereospecific formation of a 1,3-diiodide intermediate is achieved in situ by the Grignard reagent. The overall stereoablative stereochemical outcome is due to a nickel-catalyzed halogen atom abstraction with a radical rebound that is slower than epimerization of the alkyl radical. Finally, lifetimes of this alkyl radical intermediate are compared to radical clocks to enhance the understanding of the lifetime of the secondary alkyl radical.

3.
ACS Catal ; 13(7): 4488-4499, 2023 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-37066042

RESUMO

Cross-electrophile coupling reactions involving direct C-O bond activation of unactivated alkyl sulfonates or C-F bond activation of allylic gem-difluorides remain challenging. Herein, we report a nickel-catalyzed cross-electrophile coupling reaction between alkyl mesylates and allylic gem-difluorides to synthesize enantioenriched vinyl fluoride-substituted cyclopropane products. These complex products are interesting building blocks with applications in medicinal chemistry. Density functional theory (DFT) calculations demonstrate that there are two competing pathways for this reaction, both of which initiate by coordination of the electron-deficient olefin to the low-valent nickel catalyst. Subsequently, the reaction can proceed by oxidative addition of the C-F bond of the allylic gem-difluoride moiety or by directed polar oxidative addition of the alkyl mesylate C-O bond.

4.
Front Cardiovasc Med ; 9: 1038353, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36523356

RESUMO

Objective: The aim of this study is to compare the quality-of-life (QOL) outcomes and the tibio-pedal arterial pressure post-endovascular intervention. Background: Physiological assessment of peripheral arterial lesions is infrequently performed during endovascular interventions. Materials and methods: We retrospectively reviewed all 343 patients with intermittent claudication who underwent an endovascular intervention via tibio-pedal artery access from October 2018 to May 2021. The baseline and post-intervention tibio-pedal arterial pressures from the pedal sheaths were measured. QOL was assessed using a pre-validated Walking Impairment Questionnaire (WIQ) score before and at 30-day after intervention. We compared the baseline tibio-pedal arterial pressure, post-intervention tibio-pedal arterial pressure, delta pressure (post-intervention minus baseline), baseline WIQ scores, 30-day WIQ scores, and delta score (30-day minus baseline). Results: All 343 patients had successful tibio-pedal accesses. The average tibio-pedal arterial pressure at baseline was 87.0 ± 1.8 mmHg vs. 135.5 ± 1.7 mmHg post-intervention (p < 0.001). Average baseline and 30-day WIQ scores were summation (99.8 ± 3.3 vs. 115.0 ± 3.1, p < 0.001), walking distance (35.7 ± 1.3 vs. 42.5 ± 1.3, p < 0.001), walking speed (21.1 ± 0.9 vs. 23.6 ± 0.8, p = 0.036), stair climbing (4.7 ± 1.4 vs. 24.2 ± 1.4, p = 0.019), and symptoms (18.8 ± 0.2 vs. 20.1 ± 0.2, p < 0.001), respectively. When comparing the increased post-intervention tibio-pedal arterial pressure <60 mmHg vs. ≥60 mmHg, the average delta WIQ scores were all significantly improved with summation (10.0 ± 3.9 to 25.8 ± 5.5, p = 0.01), walking distance (4.1 ± 1.7 to 9.8 ± 2.5, p = 0.02), walking speed (1.5 ± 1.1 to 4.3 ± 1.5, p = 0.02), stair climbing (2.3 ± 1.8 to 9.4 ± 2.5, p = 0.02), and symptoms (1.0 ± 0.3 to 1.8 ± 0.4, p = 0.04), respectively. Conclusion: Increasing the post-intervention tibio-pedal arterial pressure by 60 mmHg can enhance QOL as suggested by improvement of WIQ scores.

5.
J Org Chem ; 87(18): 12352-12369, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36049783

RESUMO

Grignard reagents are commonly used as carbanion equivalents. Herein, we report an example of Grignard reagents acting as halide nucleophiles to form alkyl iodides and bromides. We establish that Grignard reagents can convert alkyl mesylates into alkyl halides, as well as be employed in a one-pot halogenation reaction starting from alcohols, which proceed through mesylate intermediates. The halogenation reaction is confirmed to occur by an SN2 pathway with inversion of configuration and is demonstrated to be efficient on multi-gram scale.

6.
Front Cardiovasc Med ; 9: 929472, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35911530

RESUMO

Background: Aorto-ostial interventions are challenging due to the limitations of contemporary equipment, imprecise ostial demarcation, and problematic ostial lesion characteristics. Suboptimal stent placement is common and portends worse clinical outcomes. Procedural and long-term outcomes of the bumper wire technique with intravascular ultrasound (IVUS) assessment have not been investigated. Methods: A single-center retrospective study was conducted. Patients who underwent ostial lesion percutaneous coronary intervention (PCI) with the bumper wire technique between January 2019 and September 2020 were identified. The primary endpoint was to determine the geographic miss rate defined by inadequate ostial coverage or excess stent protrusion of > 2 mm by IVUS or angiography. The secondary endpoint was target lesion failure (TLF) at 6 months after PCI, defined as the composite of cardiovascular death, target vessel myocardial infarction (MI), and target lesion revascularization. Results: In total, 45 patients were identified. The average age was 71.7 years old, and 85.4% were men. Indication for PCI was acute coronary syndrome in about a third of patients. Twenty-six patients had left main ostial lesions and 19 patients had right coronary artery ostial lesions. Geographic miss was detected in two patients (4.4%): one patient (2.2%) had excess proximal stent protrusion and one patient (2.2%) had an ostial miss. Six patients were lost to follow-up. TLF, stroke, or major bleeding were not observed in any of the patients. Conclusion: The bumper wire technique is safe and efficient with low rates of geographic miss or adverse clinical outcomes. This is the first study to confirm precise aorto-ostial stent implantation with the bumper wire technique using IVUS confirmation.

7.
Subst Abuse Treat Prev Policy ; 7: 37, 2012 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-22958624

RESUMO

BACKGROUND: Substance use disorders and perpetration of intimate partner violence (IPV) are interrelated, major public health problems. METHODS: We surveyed directors of a sample of substance use disorder treatment programs (SUDPs; N=241) and batterer intervention programs (BIPs; N=235) in California (70% response rate) to examine the extent to which SUDPs address IPV, and BIPs address substance abuse. RESULTS: Generally, SUDPs were not addressing co-occurring IPV perpetration in a formal and comprehensive way. Few had a policy requiring assessment of potential clients, or monitoring of admitted clients, for violence perpetration; almost one-quarter did not admit potential clients who had perpetrated IPV, and only 20% had a component or track to address violence. About one-third suspended or terminated clients engaging in violence. The most common barriers to SUDPs providing IPV services were that violence prevention was not part of the program's mission, staff lacked training in violence, and the lack of reimbursement mechanisms for such services. In contrast, BIPs tended to address substance abuse in a more formal and comprehensive way; e.g., one-half had a policy requiring potential clients to be assessed, two-thirds required monitoring of substance abuse among admitted clients, and almost one-half had a component or track to address substance abuse. SUDPs had clients with fewer resources (marriage, employment, income, housing), and more severe problems (both alcohol and drug use disorders, dual substance use and other mental health disorders, HIV + status). We found little evidence that services are centralized for individuals with both substance abuse and violence problems, even though most SUDP and BIP directors agreed that help for both problems should be obtained simultaneously in separate programs. CONCLUSIONS: SUDPs may have difficulty addressing violence because they have a clientele with relatively few resources and more complex psychological and medical needs. However, policy change can modify barriers to treatment integration and service linkage, such as reimbursement restrictions and lack of staff training.


Assuntos
Maus-Tratos Conjugais/prevenção & controle , Centros de Tratamento de Abuso de Substâncias/organização & administração , Transtornos Relacionados ao Uso de Substâncias/terapia , Violência/prevenção & controle , Adulto , California , Coleta de Dados , Feminino , Humanos , Masculino , Encaminhamento e Consulta/estatística & dados numéricos , Maus-Tratos Conjugais/psicologia , Centros de Tratamento de Abuso de Substâncias/métodos , Transtornos Relacionados ao Uso de Substâncias/psicologia , Resultado do Tratamento , Violência/psicologia
8.
Am J Pathol ; 180(2): 626-35, 2012 02.
Artigo em Inglês | MEDLINE | ID: mdl-22155109

RESUMO

An immature intestinal epithelial barrier may predispose infants and children to many intestinal inflammatory diseases, such as infectious enteritis, inflammatory bowel disease, and necrotizing enterocolitis. Understanding the factors that regulate gut barrier maturation may yield insight into strategies to prevent these intestinal diseases. The claudin family of tight junction proteins plays an important role in regulating epithelial paracellular permeability. Previous reports demonstrate that rodent intestinal barrier function matures during the first 3 weeks of life. We show that murine paracellular permeability markedly decreases during postnatal maturation, with the most significant change occurring between 2 and 3 weeks. Here we report for the first time that commensal bacterial colonization induces intestinal barrier function maturation by promoting claudin 3 expression. Neonatal mice raised on antibiotics or lacking the toll-like receptor adaptor protein MyD88 exhibit impaired barrier function and decreased claudin 3 expression. Furthermore, enteral administration of either live or heat-killed preparations of the probiotic Lactobacillus rhamnosus GG accelerates intestinal barrier maturation and induces claudin 3 expression. However, live Lactobacillus rhamnosus GG increases mortality. Taken together, these results support a vital role for intestinal flora in the maturation of intestinal barrier function. Probiotics may prevent intestinal inflammatory diseases by regulating intestinal tight junction protein expression and barrier function. The use of heat-killed probiotics may provide therapeutic benefit while minimizing adverse effects.


Assuntos
Claudinas/metabolismo , Mucosa Intestinal/metabolismo , Lacticaseibacillus rhamnosus/fisiologia , Probióticos/farmacologia , Animais , Animais Recém-Nascidos , Antibacterianos/farmacologia , Claudina-3 , Feminino , Intestinos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fator 88 de Diferenciação Mieloide/deficiência , Permeabilidade , RNA Mensageiro/metabolismo , Transdução de Sinais/fisiologia , Receptores Toll-Like/fisiologia
9.
J Immunol ; 184(12): 7186-95, 2010 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20483731

RESUMO

Appropriate microbial colonization protects the developing intestine by promoting epithelial barrier function and fostering mucosal tolerance to luminal bacteria. Commensal flora mediate their protective effects through TLR9-dependent activation of cytokines, such as type I IFNs (alpha, beta) and IL-10. Although IFN-beta promotes apoptosis, IFN-alpha activates specific antiapoptotic target genes whose actions preserve epithelial barrier integrity. We have recently identified guanylate binding protein-1 (GBP-1) as an antiapoptotic protein, regulated by both type I and type II IFNs, that promotes intestinal epithelial barrier integrity in mature intestine. However, the mechanisms by which commensal bacteria regulate epithelial apoptosis during colonization of immature intestine and the contributions of GBP-1 are unknown. The healthy newborn intestine is initially colonized with bacterial species present in the maternal gastrointestinal tract, including nonpathogenic Escherichia coli. Therefore, we examined the influence of commensal E. coli on cytokine expression and candidate mediators of apoptosis in preweaned mice. Specifically, enteral exposure of 2 wk-old mice to commensal E. coli for 24 h selectively increased both IFN-alphaA and GBP-1 mRNA expression and prevented staurosporine-induced epithelial apoptosis. Exogenous IFN-alphaA treatment also induced GBP-1 expression and protected against staurosporine-induced apoptosis in a GBP-1 dependent manner, both in vitro and ex vivo. These findings identify a role for IFN-alphaA-mediated GBP-1 expression in the prevention of intestinal epithelial apoptosis by commensal bacteria. Thus IFN-alphaA mediates the beneficial effects of commensal bacteria and may be a promising therapeutic target to promote barrier integrity and prevent the inappropriate inflammatory responses seen in developing intestine as in necrotizing enterocolitis.


Assuntos
Escherichia coli/imunologia , Proteínas de Ligação ao GTP/imunologia , Imunidade nas Mucosas/fisiologia , Interferon gama/imunologia , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Animais , Apoptose/imunologia , Proteínas de Ligação ao GTP/biossíntese , Expressão Gênica , Regulação da Expressão Gênica/imunologia , Humanos , Marcação In Situ das Extremidades Cortadas , Interferon gama/metabolismo , Mucosa Intestinal/crescimento & desenvolvimento , Camundongos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
10.
Bone ; 47(1): 102-10, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20362703

RESUMO

Oncogenic activation of the RAS-ERK MAP kinase signaling pathway can lead to uncontrolled proliferation but can also result in apoptosis or premature cellular senescence, both regarded as natural protective barriers to cell immortalization and transformation. In FGFR3-related skeletal dyplasias, oncogenic mutations in the FGFR3 receptor tyrosine kinase cause profound inhibition of cartilage growth resulting in severe dwarfism, although many of the precise mechanisms of FGFR3 action remain unclear. Mutated FGFR3 induces constitutive activation of the ERK pathway in chondrocytes and, remarkably, can also cause both increased proliferation and apoptosis in growing cartilage, depending on the gestational age. Here, we demonstrate that FGFR3 signaling is also capable of inducing premature senescence in chondrocytes, manifested as reversible, ERK-dependent growth arrest accompanied by alteration of cellular shape, loss of the extracellular matrix, upregulation of senescence markers (alpha-GLUCOSIDASE, FIBRONECTIN, CAVEOLIN 1, LAMIN A, SM22alpha and TIMP 1), and induction of senescence-associated beta-GALACTOSIDASE activity. Our data support a model whereby FGFR3 signaling inhibits cartilage growth via exploiting cellular responses originally designed to eliminate cells harboring activated oncogenes.


Assuntos
Senescência Celular , Condrócitos/patologia , Oncogenes/genética , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais , Animais , Apoptose , Proliferação de Células , Forma Celular , Condrócitos/enzimologia , Matriz Extracelular/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fenótipo , Ratos
11.
Gut Microbes ; 1(3): 186-95, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21327024

RESUMO

While our current knowledge of probiotic interaction in the developing gut remains poorly understood, emerging science is providing greater biological insight into their mechanism of action and therapeutic potential for human disease. Given their beneficial effects, probiotics remain promising agents in neonatal gastrointestinal disorders. Probiotics may restore or supply essential bacterial strains needed for gut maturation and homeostasis, particularly in hosts where this process has been disrupted. Here we highlight the unique characteristics of developing intestinal epithelia with a focus on gut development and colonization as well as the inflammatory propensity of immature epithelia. Additionally, we review potential mechanisms of beneficial probiotic interaction with immature intestinal epithelia including immunomodulation, upregulation of cytoprotective genes, prevention and regulation of apoptosis and maintenance of barrier function. Improved knowledge of gut-probiotic interaction in developing epithelia will allow for a better understanding of how probiotics exert their beneficial effects and help guide their therapeutic use.


Assuntos
Fenômenos Fisiológicos Bacterianos , Mucosa Intestinal/crescimento & desenvolvimento , Mucosa Intestinal/microbiologia , Probióticos/metabolismo , Animais , Tratamento Farmacológico , Humanos , Mucosa Intestinal/imunologia , Mucosa Intestinal/fisiopatologia , Probióticos/uso terapêutico
12.
Free Radic Biol Med ; 47(8): 1205-11, 2009 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-19660542

RESUMO

Uncontrolled inflammatory responses in the immature gut may play a role in the pathogenesis of many intestinal inflammatory syndromes that present in newborns or children, such as necrotizing enterocolitis (NEC), idiopathic inflammatory bowel diseases (IBD), or infectious enteritis. Consistent with previous reports that murine intestinal function matures over the first 3 weeks of life, we show that inflammatory signaling in the neonatal mouse gut increases during postnatal maturation, with peak responses occurring at 2-3 weeks. Probiotic bacteria can block inflammatory responses in cultured epithelia by inducing the generation of reactive oxygen species (ROS), which inhibit NF-kappaB activation through oxidative inactivation of the key regulatory enzyme Ubc12. We now report for the first time that the probiotic Lactobacillus rhamnosus GG (LGG) can induce ROS generation in intestinal epithelia in vitro and in vivo. Intestines from immature mice gavage fed LGG exhibited increased GSH oxidation and cullin-1 deneddylation, reflecting local ROS generation and its resultant Ubc12 inactivation, respectively. Furthermore, prefeeding LGG prevented TNF-alpha-induced intestinal NF-kappaB activation. These studies indicate that LGG can reduce inflammatory signaling in immature intestines by inducing local ROS generation and may be a mechanism by which probiotic bacteria can prevent NEC in premature infants or reduce the severity of IBD in children.


Assuntos
Inflamação , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Lacticaseibacillus rhamnosus , Probióticos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Animais Recém-Nascidos , Western Blotting , Células Cultivadas , Proteínas Culina/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Glutationa/metabolismo , Humanos , Mucosa Intestinal/patologia , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Oxirredução , Transdução de Sinais
13.
Cancer Res ; 69(14): 5876-84, 2009 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-19605406

RESUMO

Pancreatic cancer is an aggressive malignancy that is generally refractory to chemotherapy, thus posing experimental and clinical challenges. In this study, the antiproliferative effect of the triterpenoid compound cucurbitacin B was tested in vitro and in vivo against human pancreatic cancer cells. Dose-response studies showed that the drug inhibited 50% growth of seven pancreatic cancer cell lines at 10(-7) mol/L, whereas clonogenic growth was significantly inhibited at 5 x 10(-8) mol/L. Cucurbitacin B caused dose- and time-dependent G(2)-M-phase arrest and apoptosis of pancreatic cancer cells. This was associated with inhibition of activated JAK2, STAT3, and STAT5, increased level of p21(WAF1) even in cells with nonfunctional p53, and decrease of expression of cyclin A, cyclin B1, and Bcl-XL with subsequent activation of the caspase cascade. Interestingly, the combination of cucurbitacin B and gemcitabine synergistically potentiated the antiproliferative effects of gemcitabine on pancreatic cancer cells. Moreover, cucurbitacin B decreased the volume of pancreatic tumor xenografts in athymic nude mice by 69.2% (P < 0.01) compared with controls without noticeable drug toxicities. In vivo activation of JAK2/STAT3 was inhibited and expression of Bcl-XL was decreased, whereas caspase-3 and caspase-9 were up-regulated in tumors of drug-treated mice. In conclusion, we showed for the first time that cucurbitacin B has profound in vitro and in vivo antiproliferative effects against human pancreatic cancer cells, and the compound may potentate the antiproliferative effect of the chemotherapeutic agent gemcitabine. Further clinical studies are necessary to confirm our findings in patients with pancreatic cancer.


Assuntos
Apoptose/efeitos dos fármacos , Desoxicitidina/análogos & derivados , Transdução de Sinais/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Western Blotting , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desoxicitidina/administração & dosagem , Desoxicitidina/farmacologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Feminino , Citometria de Fluxo , Células Gigantes/efeitos dos fármacos , Células Gigantes/metabolismo , Células Gigantes/patologia , Humanos , Janus Quinases/metabolismo , Camundongos , Estrutura Molecular , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Fatores de Transcrição STAT/metabolismo , Fatores de Tempo , Triterpenos/administração & dosagem , Triterpenos/química , Ensaios Antitumorais Modelo de Xenoenxerto , Gencitabina
14.
Pediatr Res ; 64(5): 511-6, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18552706

RESUMO

Necrotizing enterocolitis (NEC) remains a leading cause of morbidity and mortality in preterm infants. Although its pathogenesis is poorly understood, inappropriate apoptosis of the mucosal epithelia has been implicated. Recent clinical trials have shown that probiotics may reduce the incidence of NEC, and probiotics have been shown to suppress intestinal epithelial apoptosis in cultured cells. However, little is known about their mechanism of action in the developing intestine in vivo. Here, we confirm that the probiotic Lactobacillus rhamnosus GG (LGG) reduces chemically induced intestinal epithelial apoptosis in vitro. Furthermore, we report for the first time that LGG administered orally to live animals can reduce chemically induced epithelial apoptosis ex vivo, as measured by staining for active caspase 3 and terminal deoxynucleotidyltransferase. Using cDNA microarray analysis from the intestine of live, orally inoculated mice, we show that LGG up-regulates a battery of genes with known and likely cytoprotective effects. These studies indicate that probiotics such as LGG may augment intestinal host defenses in the developing intestine by stimulating antiapoptotic and cytoprotective responses. Because apoptosis may be a precursor to NEC, understanding the mechanism behind probiotic modulation of apoptotic pathways may allow for development of more specifically targeted therapies or preventive strategies in the future.


Assuntos
Apoptose , Citoproteção , Mucosa Intestinal/microbiologia , Intestino Delgado/microbiologia , Lacticaseibacillus rhamnosus/crescimento & desenvolvimento , Probióticos , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Células CACO-2 , Citoproteção/genética , Enterocolite Necrosante/microbiologia , Enterocolite Necrosante/patologia , Enterocolite Necrosante/prevenção & controle , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/crescimento & desenvolvimento , Mucosa Intestinal/patologia , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/crescimento & desenvolvimento , Intestino Delgado/patologia , Camundongos , Camundongos Endogâmicos C57BL , Ratos , Estaurosporina/toxicidade
15.
Semin Perinatol ; 32(2): 70-82, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18346530

RESUMO

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality among infants in the neonatal intensive care unit. Here we review the epidemiology and pathophysiology of NEC, with an emphasis on the latest research findings and potential areas for future research. NEC continues to be one of the most devastating and unpredictable diseases affecting premature infants. Despite decades of research, the pathogenesis of this disease remains unclear, and prevention and treatment strategies are limited. Hopefully, future studies aimed at understanding premature intestinal defenses, commensal or probiotic bacterial influences, and possible genetic predisposition will lead to the improvement of prevention and treatment strategies.


Assuntos
Enterocolite Necrosante/complicações , Enterocolite Necrosante/prevenção & controle , Predisposição Genética para Doença , Probióticos/uso terapêutico , Digestão , Enterocolite Necrosante/etiologia , Enterocolite Necrosante/patologia , Motilidade Gastrointestinal , Humanos , Imunidade Inata , Mortalidade Infantil , Recém-Nascido , Recém-Nascido Prematuro , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia
16.
Pediatr Dermatol ; 24(5): E40-3, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17958778

RESUMO

Linear immunoglobulin A bullous disease is an autoimmune subepidermal blistering disease that has been described in both children and adults. Reports have shown that as many as two-thirds of occurrences may be drug-induced. The offending drugs include antibiotics, predominantly vancomycin, nonsteroidal anti-inflammatory agents and diuretics. We report childhood linear immunoglobulin A bullous dermatosis developing following amoxicillin-clavulanic acid administration. The patient presented with characteristic blisters in an annular fashion, likened to a ''crown of jewels.'' The diagnosis was confirmed by the presence of a linear band of immunoglobulin A at the dermoepidermal junction on direct immunofluorescence. The lesions resolved with withdrawal of the drug, and systemic therapy was not required. We review the current literature and concepts of drug-induced linear immunoglobulin A bullous disease.


Assuntos
Combinação Amoxicilina e Clavulanato de Potássio/efeitos adversos , Antibacterianos/efeitos adversos , Toxidermias/patologia , Dermatopatias Vesiculobolhosas/induzido quimicamente , Dermatopatias Vesiculobolhosas/patologia , Pré-Escolar , Toxidermias/imunologia , Humanos , Imunoglobulina A/imunologia , Masculino , Dermatopatias Vesiculobolhosas/imunologia
17.
J Exp Med ; 204(3): 547-57, 2007 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-17312008

RESUMO

The common gamma chain cytokines interleukin (IL)-2 and IL-7 are important regulators of T cell homeostasis. Although IL-2 is implicated in the acute phase of the T cell response, IL-7 is important for memory T cell survival. We asked whether regulated responsiveness to these growth factors is determined by temporal expression of the cytokine-specific IL-2 receptor (R) alpha and IL-7Ralpha chains. We demonstrate that IL-2Ralpha is expressed early after priming in T cell receptor-transgenic CD4(+) T cells, whereas IL-7Ralpha expression is lost. In the later stage of the response, IL-7Ralpha is reexpressed while IL-2Ralpha expression is silenced. This reciprocal pattern of IL-2Ralpha/IL-7Ralpha expression is disturbed when CD4(+) T cells are primed in the absence of IL-2 signals. Primed IL-2(-/-) or CD25(-/-) (IL-2Ralpha(-/-)) CD4(+) T cells, despite showing normal induction of activation markers and cell division, fail to reexpress IL-7Ralpha late in the response. Because the generation of CD4(+) memory T cells is dependent on IL-7-IL-7Ralpha interactions, primed IL-2(-/-) or CD25(-/-) CD4(+) T cells develop poorly into long-lived memory cells. Retrovirus-mediated expression of IL-7Ralpha in IL-2(-/-) T cells restores their capacity for long-term survival. These results identify IL-2 as a factor regulating IL-7Ralpha expression and, consequently, memory T cell homeostasis in vivo.


Assuntos
Adjuvantes Imunológicos/fisiologia , Linfócitos T CD4-Positivos/imunologia , Diferenciação Celular/imunologia , Memória Imunológica , Interleucina-2/fisiologia , Receptores de Interleucina-7/biossíntese , Animais , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/metabolismo , Diferenciação Celular/genética , Células Cultivadas , Regulação da Expressão Gênica/imunologia , Homeostase/genética , Homeostase/imunologia , Memória Imunológica/genética , Subunidade alfa de Receptor de Interleucina-2/biossíntese , Subunidade alfa de Receptor de Interleucina-2/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Camundongos Transgênicos , Receptores de Interleucina-7/genética
18.
Lancet ; 368(9543): 1271-83, 2006 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-17027734

RESUMO

Necrotising enterocolitis is one of the most common gastrointestinal emergencies in newborn infants. Here we review the epidemiology, clinical presentation, and pathophysiology of the disease, as well as strategies for diagnosis, management, and prevention. Necrotising enterocolitis is one of the most devastating and unpredictable diseases affecting premature infants. Despite decades of research, its pathogenesis remains unclear; diagnosis can be difficult; and treatment is challenging. We will need to improve our understanding of intestinal defences in premature infants, dietary and bacterial factors, and genetic effects that could predispose infants to necrotising enterocolitis before we can develop new strategies for prevention and treatment.


Assuntos
Enterocolite Necrosante/fisiopatologia , Enterocolite Necrosante/diagnóstico , Enterocolite Necrosante/epidemiologia , Feminino , Mortalidade Hospitalar , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Recém-Nascido Prematuro , Tempo de Internação , Masculino , Prevalência
19.
Am J Physiol Gastrointest Liver Physiol ; 290(1): G96-G108, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16179598

RESUMO

Flagellin, the primary structural component of bacterial flagella, is recognized by Toll-like receptor 5 (TLR5) present on the basolateral surface of intestinal epithelial cells. Utilizing biochemical assays of proinflammatory signaling pathways and mRNA expression profiling, we found that purified flagellin could recapitulate the human epithelial cell proinflammatory responses activated by flagellated pathogenic bacteria. Flagellin-induced proinflammatory activation showed similar kinetics and gene specificity as that induced by the classical endogenous proinflammatory cytokine TNF-alpha, although both responses were more rapid than that elicited by viable flagellated bacteria. Flagellin, like TNF-alpha, activated a number of antiapoptotic mediators, and pretreatment of epithelial cells with this bacterial protein could protect cells from subsequent bacterially mediated apoptotic challenge. However, when NF-kappaB-mediated or phosphatidylinositol 3-kinase/Akt proinflammatory signaling was blocked, flagellin could induce programmed cell death. Consistently, we demonstrate that flagellin and viable flagellate Salmonella induces both the extrinsic and intrinsic caspase activation pathways, with the extrinsic pathway (caspase 8) activated by purified flagellin in a TLR5-dependant fashion. We conclude that interaction of flagellin with epithelial cells induces caspase activation in parallel with proinflammatory responses. Such intertwining of proinflammatory and apoptotic signaling mediated by bacterial products suggests roles for host programmed cell death in the pathogenesis of enteric infections.


Assuntos
Apoptose , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Flagelina/metabolismo , Salmonella typhimurium/fisiologia , Receptor 5 Toll-Like/metabolismo , Caspases/genética , Linhagem Celular , Ativação Enzimática , Perfilação da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Humanos , Inflamação/metabolismo , Inflamação/microbiologia , NF-kappa B/metabolismo , Transdução de Sinais , Transcrição Gênica , Fator de Necrose Tumoral alfa/metabolismo , Regulação para Cima
20.
Ann Behav Med ; 30(2): 164-73, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16173913

RESUMO

BACKGROUND: The chronic illness model encourages consideration of patients' treatment preferences. Moreover, research suggests that matching treatment to preference might affect outcomes for patients with depression. PURPOSE: This investigation explored factors associated with treatment preference matching and the effects of matching on depression treatment outcomes. METHODS: Treatment preferences were assessed among primary care patients with depression participating in a large randomized trial of depression management. Patients were offered antidepressant medication and/or counseling based on preference and several other factors. Depression was assessed at 3 and 9 months. RESULTS: Participants who preferred medication were older, were in worse physical health, and were more likely to already be taking antidepressants. Participants who preferred both medication and counseling evidenced greater agreement with the statement that depression is a medical illness. Overall, 72% of participants were matched with their preferred treatment; matched participants demonstrated more rapid improvement in depression symptomatology than unmatched participants. CONCLUSIONS: Obtaining preferred treatment appears to contribute to improved treatment outcome. Continued attempts to assess for and accommodate treatment preferences might result in better response to depression treatment.


Assuntos
Antidepressivos/uso terapêutico , Depressão/psicologia , Depressão/terapia , Aceitação pelo Paciente de Cuidados de Saúde , Psicoterapia/estatística & dados numéricos , Idoso , Comportamento Cooperativo , Aconselhamento/estatística & dados numéricos , Atenção à Saúde , Depressão/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Satisfação do Paciente , Ensaios Clínicos Controlados Aleatórios como Assunto , Análise de Regressão
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