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1.
J Allergy Clin Immunol ; 154(1): 222-228.e4, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38521096

RESUMO

BACKGROUND: Acute infusion reactions to oxaliplatin, a chemotherapeutic used to treat gastrointestinal cancers, are observed in about 20% of patients. Rapid drug desensitization (RDD) protocols often allow the continuation of oxaliplatin in patients with no alternative options. Breakthrough symptoms, including anaphylaxis, can still occur during RDD. OBJECTIVE: Our aim was to evaluate whether pretreatment with acalabrutinib, a Bruton tyrosine kinase inhibitor, can prevent anaphylaxis during RDD in a patient sensitized to oxaliplatin. METHODS: A 52-year-old male with locally advanced gastric carcinoma developed anaphylaxis during his fifth cycle of oxaliplatin. As he required 6 additional cycles to complete his curative-intent treatment regimen, he underwent RDD to oxaliplatin but still developed severe acute reactions. The risks and benefits of adding acalabrutinib before and during RDD were reviewed, and the patient elected to proceed. RESULTS: With acalabrutinib taken before and during the RDD, the patient was able to tolerate oxaliplatin RDD without complication. Consistent with its mechanism of action, acalabrutinib completely blocked the patient's positive skin prick response to oxaliplatin. Acalabrutinib did not alter the percentage of circulating basophils (1.24% vs 0.98%) before the RDD but did protect against basopenia (0.74% vs 0.09%) after the RDD. Acalabrutinib was associated with a drastic reduction in the ability of basophils to upregulate CD63 in vitro following incubation with oxaliplatin (0.11% vs 2.38%) or polyclonal anti-human IgE antibody (0.08% vs 44.2%). CONCLUSIONS: Five doses of acalabrutinib, 100 mg, orally twice daily starting during the evening 2 days before and continuing through RDD allowed a sensitized patient to receive oxaliplatin successfully and safely.


Assuntos
Tirosina Quinase da Agamaglobulinemia , Antineoplásicos , Benzamidas , Dessensibilização Imunológica , Hipersensibilidade a Drogas , Oxaliplatina , Pirazinas , Humanos , Oxaliplatina/efeitos adversos , Pessoa de Meia-Idade , Masculino , Hipersensibilidade a Drogas/imunologia , Hipersensibilidade a Drogas/prevenção & controle , Dessensibilização Imunológica/métodos , Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Pirazinas/efeitos adversos , Pirazinas/administração & dosagem , Pirazinas/uso terapêutico , Benzamidas/uso terapêutico , Benzamidas/administração & dosagem , Antineoplásicos/efeitos adversos , Anafilaxia/prevenção & controle , Anafilaxia/induzido quimicamente , Anafilaxia/imunologia , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/imunologia
2.
Clin Exp Allergy ; 52(7): 859-867, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35524339

RESUMO

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) is a type 2 inflammatory disease of the upper airways. AZD1981 is a selective antagonist of chemoattractant receptor-homologous molecule expressed on T helper type 2 and other type 2 cells, including innate lymphoid cells type 2, eosinophils, and basophils. OBJECTIVE: To evaluate the efficacy of AZD1981 in reducing nasal polyp size when added to intranasal corticosteroids in adult patients with CRSwNP. METHODS: Eighty-one subjects (18-70 years of age) with CRSwNP were recruited and screened for trial eligibility from allergy and otolaryngology clinics from a single tertiary care site between June 2016 and August 2019. Eligible patients were randomized in a double-blind fashion to receive either AZD1981 (n = 22) or placebo (n = 21) orally three times a day for 12 weeks, added to intranasal corticosteroids. The primary endpoint was a change in nasal polyp score (NPS) at 12 weeks. Secondary endpoints included improvement in sinus computed tomography using Lund Mackay scoring, symptoms using visual analog scale, quality of life using Sino Nasal Outcome Test-22, and the Brief Smell Identification Test. RESULTS: Forty-three patients met the inclusion criteria and were enrolled. At 12 weeks, there was no difference in NPS change in the AZD1981 arm (mean 0, standard error 0.34, n = 15) compared with placebo (mean 0.20, standard error 0.36, n = 17); mean difference -0.20 (95% confidence interval: -1.21, 0.81; p = .69). No significant differences were observed for Lund Mackay score, symptoms, quality of life, or smell test. AZD1981 was well tolerated except for one case of hypersensitivity reaction. CONCLUSION: In patients with CRSwNP, the addition of AZD1981 to intranasal corticosteroids did not change nasal polyp size, radiographic scores, symptoms, or disease-specific quality of life.


Assuntos
Pólipos Nasais , Rinite , Sinusite , Acetatos , Corticosteroides/uso terapêutico , Adulto , Doença Crônica , Humanos , Imunidade Inata , Indóis , Linfócitos , Pólipos Nasais/complicações , Pólipos Nasais/tratamento farmacológico , Qualidade de Vida , Rinite/complicações , Rinite/tratamento farmacológico , Sinusite/tratamento farmacológico
3.
Artigo em Inglês | MEDLINE | ID: mdl-30473713

RESUMO

BACKGROUND: Chorioamnionitis is a risk factor for future asthma development. Animal models of chorioamnionitis demonstrate increased TH17-to-Treg ratios associated with proinflammatory cytokine elevations. The association of chorioamnionitis on human neonatal immune cells systemically and within tissues is not known. METHODS: We enrolled two cohorts to evaluate TH17 and regulatory T cell (Treg) phenotypic markers in chorioamnionitis. From a cohort of 19 live birth infants, we collected cord blood and placenta samples to evaluate for signs of acute and chronic histologic inflammation and cell phenotype characterization. We analyzed a second cohort of stillborn infants with and without chorioamnionitis to classify and enumerate cell infiltrate phenotypes in the spleen, thymus, and lung. We used linear regression analysis determine the association of retinoic acid-related orphan receptor gamma t positive (RORγt+) and Treg cell frequency with different types of inflammation seen in the live cohort subjects. Using linear mixed models, we evaluated for any associations between chorioamnionitis and T- and B-cell with a logarithmic scale for level of expression of cellular markers. We then performed Wilcoxon rank sum tests to assess the associations between cell count and chorioamnionitis. RESULTS: In the live birth subjects with chronic placental inflammation we observed an increased proportion of RORγt+ cells in Foxp3+ cells, regardless of the presence of acute inflammation, compared to subjects with neither acute nor chronic inflammation. We also found an increased proportion of RORγt+ cells within Foxp3+ cells in subjects with acute high stage fetal and maternal inflammation compared to those without acute or chronic inflammation. In the stillborn subjects with chorioamnionitis, we observed a decrease in splenic Foxp3+ cells and an increase in lung CD3+ cells compared with subjects that did not have chorioamnionitis. CONCLUSION: Exposure to chorioamnionitis in utero may affect immune activation in neonates with an increased frequency of RORγt+ cells systemically as well as lymphocytic infiltrate in the lung. Our findings suggest an increase in RORγt+ cells during chorioamnionitis and thus may support the known associations between chorioamnionitis with asthma.

4.
Prog Community Health Partnersh ; 11(1): 87-91, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28603155

RESUMO

BACKGROUND: In 2008, the Minnesota Department of Health (MDH) awarded Statewide Health Improvement Partnership (SHIP) funding to community health boards (CHBs), directing them to partner with schools, worksites, communities, and health care to address obesity and tobacco use/exposure. METHODS: Each CHB selected one of two health care strategies: implement obesity and healthy lifestyle guidelines or connect clinics to community resources. The CHB in rural west-central Minnesota chose to champion clinical guideline implementation, assigning one of its own county-level public health nurses the role of practice facilitator (PF). This decision set the stage for a novel community partnership between public health, clinical guideline developers, and local providers of relevant clinical services. LESSONS LEARNED: This community perspective describes how the PF organized support for clinical guideline implementation using the TRANSLATE framework, and explores the capacity of the TRANSLATE framework to accommodate particularities of clinical partners that is necessary in working to transform evidence-based knowledge into real-world practice.


Assuntos
Fidelidade a Diretrizes , Promoção da Saúde/organização & administração , Melhoria de Qualidade , Pesquisa Participativa Baseada na Comunidade , Prática Clínica Baseada em Evidências , Humanos , Minnesota , Inovação Organizacional , Objetivos Organizacionais , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Saúde Pública , População Rural
6.
Public Health Nurs ; 32(1): 34-42, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25040771

RESUMO

OBJECTIVE: The purpose of the study was to investigate the perceptions of administrators and clinicians regarding a public health facilitated collaborative supporting the translation into practice of the Institute for Clinical Systems Improvement (ICSI) Adult Obesity Guideline. DESIGN AND SAMPLE: This qualitative study was conducted with 10 health care organizations participating in a voluntary, interprofessional obesity management collaborative. A purposive sample of 39 participants included two to three clinicians and an administrator from each organization. Interview analysis focused on how the intervention affected participants and their practices. RESULTS: Four themes described participant experiences of obesity guideline translation: (1) a shift from powerlessness to positive motivation, (2) heightened awareness coupled with improved capacity to respond, (3) personal ownership and use of creativity, and (4) a sense of the importance of increased interprofessional collaboration. CONCLUSIONS: The investigation of interprofessional perspectives illuminates the feelings and perceptions of clinician and administrator participants regarding obesity practice guideline translation. These themes suggest that positive motivation, improved capacity, personal creative ownership, and interprofessional collaboration may be conducive to successful evidence-based obesity guideline implementation. Further research is needed to evaluate these findings relative to translating the ICSI obesity guideline and other guidelines into practice in diverse clinical settings.


Assuntos
Atitude do Pessoal de Saúde , Enfermeiros de Saúde Pública/organização & administração , Obesidade/enfermagem , Guias de Prática Clínica como Assunto , Adulto , Comportamento Cooperativo , Feminino , Humanos , Masculino , Pesquisa Qualitativa
7.
Public Health Nurs ; 32(3): 222-31, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25424421

RESUMO

OBJECTIVE(S): A public health nurse (PHN) in the Midwestern United States (U.S.) led a collaborative system-level intervention to translate the Institute of Clinical Systems Improvement (ICSI) Adult Obesity Guideline into interprofessional practice. This study (1) evaluated the extent of guideline translation across organizations and (2) assessed the Omaha System as a method for translating system-level interventions and measuring outcomes. DESIGN AND SAMPLE: This retrospective, mixed methods study was conducted with a purposeful sample of one administrator (n = 10) and two to three clinicians (n = 29) from each organization (n = 10). MEASURES: Omaha System Problem Rating Scale for Outcomes Knowledge, Behavior, and Status (KBS). KBS ratings gathered from semi-structured interviews and Omaha System documentation were analyzed using standard descriptive and inferential statistics and triangulated findings with participant quotes. RESULTS: KBS ratings and participant quotes revealed intervention effectiveness in creating sustained system-level changes. Self-reported and observed KBS ratings demonstrated improvement across organizations. There was moderate to substantial agreement regarding benchmark attainment within organizations. On average, self-reported improvement exceeded observer improvement. CONCLUSIONS: System-level PHN practice facilitator interventions successfully translated clinical obesity guidelines into interprofessional use in health care organizations. The Omaha System Problem Rating Scale for Outcomes reliably measured system-level outcomes.


Assuntos
Obesidade/terapia , Avaliação de Resultados em Cuidados de Saúde/métodos , Guias de Prática Clínica como Assunto/normas , Adulto , Benchmarking , Comportamento Cooperativo , Humanos , Meio-Oeste dos Estados Unidos , Enfermagem em Saúde Pública , Estudos Retrospectivos , Vocabulário Controlado
9.
Mil Med ; 178(1): 34-6, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23356116

RESUMO

Vehicle-mounted high-power microwave systems have been developed to counter the improvised explosive device threat in southwest Asia. Many service members only vaguely comprehend the nature of these devices and the nonionizing radio frequency (RF) radiation they emit. Misconceptions about the health effects of RF radiation have the potential to produce unnecessary anxiety. We report an incident in which concern for exposure to radiation from a high-power microwave device thought to be malfunctioning led to an extensive field investigation, multiple evaluations by clinicians in theater, and subsequent referrals to an Occupational Health clinic upon return from deployment. When acute exposure to RF does occur, the effects are thermally mediated and immediately perceptible--limiting the possibility of injury. Unlike ionizing radiation, RF radiation is not known to cause cancer and the adverse health effects are not cumulative. Medical officers counseling service members concerned about potential RF radiation exposure should apply established principles of risk communication, attend to real and perceived risks, and enlist the assistance of technical experts to properly characterize an exposure when appropriate.


Assuntos
Comunicação em Saúde , Micro-Ondas , Militares , Exposição Ocupacional , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Veículos Automotores
10.
Carbohydr Polym ; 90(3): 1216-25, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22939334

RESUMO

The preparation and characterization of natural polymer-based hydrogels that contain 50-nm diameter magnetite (i.e., FeO:Fe(2)O(3)) nanoparticles are described herein. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the efficiency of the polysaccharide-modifying process. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and compressive moduli demostrate that the presence of magnetite improves thermal and mechanical resistance. Transient diffusion of water in magnetic hydrogels was analyzed via boundary layer mass transfer across an expaning interface, and the degree of swelling of these polysaccharide hydrogels decreases in the presence of magnetite, with no variation in the binary diffusion mechanism. The absence of hysteresis loops and coercivity observed via magnetometry suggests that magnetic hydrogels are useful for remote-controlled drug release, as demonstrated by magnetic-field-induced release of curcumin. Experiments reveal that magnetic hydrogels with greater magnetic susceptibility have the potential to release larger concentrations of drugs from the hydrogel network.


Assuntos
Preparações de Ação Retardada/química , Óxido Ferroso-Férrico/química , Hidrogéis/química , Polissacarídeos/química , Campos Magnéticos
11.
Acta Biomater ; 8(4): 1551-9, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22210184

RESUMO

Here we present a novel matrix-mimetic nanoassembly based on polysaccharides. Chitosan electrospun fiber networks are decorated with heparin-containing polyelectrolyte complex nanoparticles (PCNs) that present basic fibroblast growth factor (FGF-2), both stably adsorbed to the surfaces and released into solution. These FGF-2/PCN complexes can be released from the fibers with zero-order kinetics over a period of 30 days. Further modification of fibers with a single bilayer of polyelectrolyte multilayer (PEM) composed of N,N,N-trimethyl chitosan and heparin completely prevent release, and the FGF-2/PCN complexes are retained on the fibers for the duration of the release experiment (30 days). We also compare the mitogenic activity of these FGF-2/PCN complexes delivered in two different states: adsorbed to a surface and dissolved in solution. FGF-2/PCN complexes exhibit mitogenic activity with respect to ovine bone marrow-derived mesenchymal stem cells, even after being preconditioned by incubating for 27 days at 37°C in solution. However, when the FGF-2/PCN complexes are adsorbed to chitosan and coated with PEMs, the mitogenic activity of the FGF-2 steadily decreases with increasing preconditioning time. This work demonstrates a new system for stabilizing and controlling the delivery of heparin-binding growth factors, using polysaccharide-based matrix-mimetic nanomaterials. This work also contributes to our understanding of the preferred mode of growth factor delivery from porous scaffolds.


Assuntos
Quitosana/química , Sistemas de Liberação de Medicamentos/métodos , Fator 2 de Crescimento de Fibroblastos/farmacologia , Heparina/química , Nanopartículas/química , Nanotecnologia/métodos , Animais , Eletrólitos , Feminino , Humanos , Cinética , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Microscopia Confocal , Nanopartículas/ultraestrutura , Ovinos , Sus scrofa
12.
Biomacromolecules ; 12(7): 2755-65, 2011 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-21644518

RESUMO

Polyelectrolyte multilayers using the polycations chitosan and N,N,N-trimethyl chitosan and the polyanions hyaluronan, chondroitin sulfate, and heparin are studied. Chitosan and hyaluronan behave as a weak polycation and weak polyanion, respectively, whereas N,N,N-trimethyl chitosan, chondroitin sulfate, and heparin behave as strong polyelectrolytes. Hydrophilicity is determined by water contact angle measurements and by comparing wet and dry film thickness measurements. Wet thickness is obtained using Fourier transform surface plasmon resonance, whereas dry thickness is obtained through ellipsometry. For the very thin PEMs studied here, the surface hydrophilicity and swelling in water are highly correlated. The multilayer chemistry is assessed by FT-IR and X-ray photoelectron spectroscopy (XPS). FT-IR and XPS provide information about the composition, degree of ionization, and by inference, the ion pairing. We find that hydrophilicity and swelling are reduced when one polyelectrolyte is strong and the other is weak, whereas ion pairing is increased. By this combination of techniques, we are able to compose a unified description of how the PEM swelling is dictated by the ion pairing in thin polysaccharide-based PEMs.


Assuntos
Membranas Artificiais , Polissacarídeos/química , Configuração de Carboidratos , Eletrólitos/síntese química , Eletrólitos/química , Espectrofotometria , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química , Molhabilidade , Raios X
13.
Am J Physiol Regul Integr Comp Physiol ; 296(5): R1661-70, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19279288

RESUMO

Hyperexcitability of C-fiber bladder afferent pathways has been proposed to contribute to urinary frequency and bladder pain in chronic bladder inflammation including interstitial cystitis. However, the detailed mechanisms inducing afferent hyperexcitability after bladder inflammation are not fully understood. Thus, we investigated changes in the properties of bladder afferent neurons in rats with bladder inflammation induced by intravesical application of hydrochloric acid. Eight days after the treatment, bladder function and bladder sensation were analyzed using cystometry and an electrodiagnostic device of sensory function (Neurometer), respectively. Whole cell patch-clamp recordings and immunohistochemical staining were also performed in dissociated bladder afferent neurons identified by a retrograde tracing dye, Fast Blue, injected into the bladder wall. Cystitis rats showed urinary frequency that was inhibited by pretreatment with capsaicin and bladder hyperalgesia mediated by C-fibers. Capsaicin-sensitive bladder afferent neurons from sham rats exhibited high thresholds for spike activation and a phasic firing pattern, whereas those from cystitis rats showed lower thresholds for spike activation and a tonic firing pattern. Transient A-type K(+) current density in capsaicin-sensitive bladder afferent neurons was significantly smaller in cystitis rats than in sham rats, although sustained delayed-rectifier K(+) current density was not altered after cystitis. The expression of voltage-gated K(+) Kv1.4 alpha-subunits, which can form A-type K(+) channels, was reduced in bladder afferent neurons from cystitis rats. These data suggest that bladder inflammation increases bladder afferent neuron excitability by decreasing expression of Kv1.4 alpha-subunits. Similar changes in capsaicin-sensitive C-fiber afferent terminals may contribute to bladder hyperactivity and hyperalgesia due to acid-induced bladder inflammation.


Assuntos
Cistite/metabolismo , Canal de Potássio Kv1.4/metabolismo , Neurônios Aferentes/fisiologia , Subunidades Proteicas/metabolismo , Bexiga Urinária Hiperativa/metabolismo , Bexiga Urinária/inervação , Animais , Capsaicina/farmacologia , Cistite/induzido quimicamente , Modelos Animais de Doenças , Feminino , Ácido Clorídrico/efeitos adversos , Fibras Nervosas Amielínicas/efeitos dos fármacos , Fibras Nervosas Amielínicas/metabolismo , Neurônios Aferentes/efeitos dos fármacos , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Fármacos do Sistema Sensorial/farmacologia , Bexiga Urinária Hiperativa/induzido quimicamente
14.
Am J Physiol Renal Physiol ; 288(3): F466-73, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15692058

RESUMO

Substance P (SP) binding to neurokinin 1 receptors (NK1R) in the spinal cord reportedly plays an important role in the micturition reflex as well as in nociceptive responses. We therefore investigated the effect of ablation of NK1R-expressing neurons in the spinal cord using saporin, a ribosome-inactivating protein, conjugated with [Sar9, Met (O2)11]SP, a specific ligand of NK1R (SSP-saporin), on the micturition reflex in rats. In female Sprague-Dawley rats, SSP-saporin (1.0 or 1.5 microM) or saporin (1.5 microM) only was injected through an intrathecal catheter implanted at the L6-S1 level of the spinal cord. Three weeks after intrathecal administration of SSP-saporin, NK1R immunoreactivity in lamina I of the spinal cord was significantly reduced, but cystometric parameters in awake rats were not altered. Instillation of capsaicin (15 microM) into the bladder of normal rats induced bladder overactivity. This response to capsaicin was significantly suppressed in SSP-saporin-treated animals. SSP-saporin treatment also decreased c-fos expression in the dorsal horn of the spinal cord induced by instillation of capsaicin into the bladder. These data indicate that NK1R-expressing neurons in the superficial layer of the dorsal horn play an important role in transmission of nociceptive afferent information from the bladder to induce bladder overactivity and spinal c-fos expression elicited by bladder irritation. Toxin-induced damage of NK1R-expressing neurons in the lumbosacral spinal cord may provide an effective modality for treating overactivity and/or nociceptive responses in the bladder without affecting normal micturition.


Assuntos
Cistite/metabolismo , Genes fos/genética , Neurônios/metabolismo , Neurônios/fisiologia , Receptores da Neurocinina-1/metabolismo , Medula Espinal/metabolismo , Medula Espinal/fisiologia , Substância P/análogos & derivados , Bexiga Urinaria Neurogênica/fisiopatologia , Animais , Capsaicina/farmacologia , Núcleo Celular/metabolismo , Feminino , Imunofluorescência , Imuno-Histoquímica , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Ratos Sprague-Dawley , Substância P/farmacologia , Bexiga Urinária/patologia
15.
Eur J Neurosci ; 20(2): 474-82, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15233756

RESUMO

In order to clarify the functional role of the isolectin B4 (IB4)-binding afferent pathway in the micturition reflex, we investigated the effects on bladder activity of intrathecal application of the IB4-saporin conjugate, a targeting cytotoxin that destroys neurons binding IB4. In rats, IB4-saporin (2.5 micro m) or vehicle was administered through an intrathecal catheter implanted at the level of the L6-S1 spinal cord. Three weeks after IB4-saporin administration, cystometry in conscious animals revealed a reduction in bladder overactive responses induced by intravesical capsaicin or ATP infusion without affecting normal voiding function. In histochemical studies, double staining for IB4 and saporin was detected in L6 dorsal root ganglia (DRG) neurons 2 days after the treatment. Three weeks after the treatment, the area in lamina II of the L6 spinal cord stained with IB4 was significantly reduced compared with the area stained in control rats. The staining in the L1 spinal cord was not affected. The percentage of neurons in the L6 DRG intensely labeled with IB4 was also reduced in IB4-saporin-treated rats. These results indicate that intrathecal treatment with the IB4-saporin conjugate at the level of L6-S1 spinal cord, which reduces IB4 afferent nerve terminal staining in lamina II of the L6 spinal cord as well as the number of IB4-binding neurons in L6 DRG, suppressed bladder overactivity induced by bladder irritation without affecting normal micturition. Thus targeting IB4-binding, non-peptidergic afferent pathways sensitive to capsaicin and adenosine 5'-triphosphate may be an effective treatment for overactivity and/or pain responses in the bladder.


Assuntos
Imunotoxinas/toxicidade , Lectinas/toxicidade , N-Glicosil Hidrolases/toxicidade , Proteínas de Plantas/toxicidade , Bexiga Urinaria Neurogênica/induzido quimicamente , Bexiga Urinária/efeitos dos fármacos , Trifosfato de Adenosina/farmacologia , Animais , Capsaicina/farmacologia , Citotoxinas/toxicidade , Interações Medicamentosas , Feminino , Citometria de Fluxo/métodos , Técnicas Histológicas , Imunotoxinas/metabolismo , N-Glicosil Hidrolases/metabolismo , Proteínas de Plantas/metabolismo , Células do Corno Posterior/efeitos dos fármacos , Células do Corno Posterior/fisiopatologia , Ratos , Ratos Sprague-Dawley , Proteínas Inativadoras de Ribossomos Tipo 1 , Saporinas , Medula Espinal/citologia , Medula Espinal/efeitos dos fármacos , Bexiga Urinária/efeitos da radiação
16.
J Neurosci ; 23(10): 4355-61, 2003 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-12764124

RESUMO

We investigated whether primary afferent neurons innervating different regions of the lower urinary tract have different histochemical and electrophysiological properties. Neurons in rat L6-S1 DRG were identified by axonal transport of a fluorescent dye. Neurofilament-negative C-fiber cells comprise approximately 70% of bladder and proximal urethral afferent neurons that send axons through the pelvic nerves, but comprise a smaller proportion (51%) of distal urethral neurons that send axons through the pudendal nerves. Isolectin-B4 (IB4) binding was detected in a higher percentage (49%) of C-fiber neurons innervating the distal urethra than in those innervating the bladder or proximal urethra (18-22%). Neurofilament-positive A-fiber neurons innervating the distal urethra had a larger average somal size than neurons innervating the bladder or proximal urethra. In patch-clamp recordings, the majority (70%) of bladder and proximal urethral neurons were sensitive to capsaicin and exhibited TTX-resistant, high-threshold action potentials, whereas a smaller proportion (53%) of distal urethral neurons exhibited TTX-resistant spikes. T-type Ca2+ currents were observed in 47% of distal urethral neurons with TTX-sensitive spikes, but not in TTX-sensitive bladder or proximal urethral neurons. In summary, afferent neurons innervating bladder or proximal urethra differ from those innervating distal urethra. The latter, which more closely resemble cutaneous afferent neurons, consist of a smaller number of C-fiber neurons containing a higher percentage of IB4-positive cells and a more diverse population of A-fiber neurons, some of which exhibit T-type Ca2+ channels. These differences may be related to different functions of respective target organs in the lower urinary tract.


Assuntos
Gânglios Espinais/fisiologia , Neurônios Aferentes/fisiologia , Técnicas de Patch-Clamp , Sistema Urinário/inervação , Amidinas/metabolismo , Animais , Transporte Axonal/efeitos dos fármacos , Transporte Axonal/fisiologia , Canais de Cálcio Tipo T/metabolismo , Canais de Cálcio Tipo T/fisiologia , Capsaicina/farmacologia , Feminino , Corantes Fluorescentes/metabolismo , Gânglios Espinais/química , Gânglios Espinais/citologia , Gânglios Espinais/efeitos dos fármacos , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Proteínas de Neurofilamentos/análise , Proteínas de Neurofilamentos/imunologia , Neurônios Aferentes/química , Neurônios Aferentes/efeitos dos fármacos , Lectinas de Plantas/metabolismo , Ratos , Ratos Sprague-Dawley , Tetrodotoxina/farmacologia , Uretra/química , Uretra/citologia , Uretra/efeitos dos fármacos , Uretra/inervação , Bexiga Urinária/química , Bexiga Urinária/citologia , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/inervação , Sistema Urinário/efeitos dos fármacos
17.
Inorg Chem ; 42(4): 932-4, 2003 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-12588119

RESUMO

Triazapentadienides, C(3)F(7)-C(=NR)-N=C(NHR)-C(3)F(7), result from the reaction of primary amines RNH(2) with the fluorinated imine C(3)F(7)-CF=N-C(4)F(9). The aniline derivative (R = Ph) is a weak monoprotic acid in dmso. Its conjugate base exhibits an extensive coordination chemistry. It acts as a bidentate ligand toward the molecular fragments Pd(C(3)H(5)), Rh(c-C(8)H(12)), Ir(c-C(8)H(12)), and Rh(CO)(2). The chelates [C(3)F(7)-C(NPh)-N-C(NPh)-C(3)F(7)](2)M, M = Mg, Mn, Fe, Co, Ni, Cu, Zn, and Pd, were prepared. In the crystallographically characterized Co complex, the metal is 3d(7), S = (3)/(2) and tetrahedrally coordinated. Spin densities at carbon in the C(6)H(5) and C(3)F(7) groups were estimated from the (1)H and (19)F contact shifts. Spin delocalization onto phenyl sp(2) carbons is approximately 10 times greater than onto the fluorinated sp(3) carbons.

18.
Toxicol Sci ; 65(1): 35-42, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11752683

RESUMO

The metabolism and genotoxicity of the carcinogenic mycotoxin, aflatoxin B1 (AFB), was studied in the lower eukaryotic yeast Saccharomyces cerevisiae. Recombinant strains of yeast were engineered to express human cDNAs for CYP1A1, CYP1A2, and microsomal epoxide hydrolase (mEH). Coexpression of mEH with CYP1A1 or CYP1A2 resulted in significant decreases in measurements of AFB genotoxicity. In cells expressing CYP1A2 and mEH, the level of AFB-DNA adducts was decreased by 50% relative to cells expressing CYP1A2 alone. Mitotic recombination, as assayed by gene conversion at the trp5 locus, was diminished by 50% or greater in cells coexpressing mEH and CYP1A2 compared to CYP1A2 alone. The mutagenicity of AFB in the Ames assay was also decreased by approximately 50% when AFB was incubated with microsomes containing CYP1A1 or CYP1A2 and mEH versus CYP1A1 or CYP1A2 alone. The biotransformation of AFB by CYPs is known to involve the generation of a reactive epoxide intermediate, AFB-8,9-epoxide, but previous direct biochemical and kinetic studies have failed to demonstrate any functional role for mEH in AFB detoxification. By reconstructing a metabolic pathway in intact yeast, we have shown, for the first time, that mEH may play a role in mitigating the carcinogenic effects of AFB.


Assuntos
Aflatoxina B1/toxicidade , Epóxido Hidrolases/metabolismo , Microssomos/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos , Aflatoxina B1/metabolismo , Citocromo P-450 CYP1A1/efeitos dos fármacos , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP1A2/efeitos dos fármacos , Citocromo P-450 CYP1A2/genética , Citocromo P-450 CYP1A2/metabolismo , Adutos de DNA/efeitos dos fármacos , Epóxido Hidrolases/administração & dosagem , Epóxido Hidrolases/genética , Regulação Enzimológica da Expressão Gênica , Humanos , Microssomos/enzimologia , Testes de Mutagenicidade , Organismos Geneticamente Modificados , Plasmídeos , Saccharomyces cerevisiae/enzimologia
19.
Oecologia ; 109(4): 608-614, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28307346

RESUMO

Although a predator's mass should influence the suitability of its prey, this subject has received little direct attention. We studied the capture and processing of an abundant syrphid fly Toxomerus marginatus (c. 4 mg) by 0.6- to 40-mg juvenile crab spiders Misumena vatia (Thomisidae) to determine how profitability, relative profitability (profitability/predator mass), overall gain in mass, and relative gain in mass differed with predator mass, and whether foraging changed concurrently. In multi-prey experiments, the smallest successful spiders (0.6-3.0 mg) extracted less mass from flies, and did so more slowly, than large spiders. This gain was proportionately similar to that of 10- to 40-mg spiders with access to many Toxomerus. However, many small spiders failed to capture flies. When we gave spiders only a single Toxomerus, the smallest ones again extracted mass more slowly than the large ones and increased in mass less than the large ones, but increased in mass proportionately more than large ones. Relative gain in mass from a single prey decreased with increasing spider mass. Spiders larger than 10 mg all extracted similar amounts of mass from a single Toxomerus at similar rates, but varied in time spent between captures. Thus, Toxomerus changes with spider mass from a large, hard-to-capture bonanza to a small, easy-to-capture item of low per capita value. However, Toxomerus is common enough that large spiders can capture it en masse, thereby compensating for its decline in per capita value.

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