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1.
Pituitary ; 27(2): 129-140, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38189862

RESUMO

PURPOSE: This study was undertaken to assess the unmet needs within the endogenous Cushing's syndrome (CS) care paradigm from the endocrinologist's perspective, including data abstracted from patient charts. The study evaluated endocrinologists' perceptions on burden of illness and treatment rationale along with the long-term clinical burden of CS, tolerability of CS treatments, and healthcare resource utilization for CS. METHODS: Retrospective medical chart data from treated patients with a confirmed diagnosis of CS was abstracted using a cross-sectional survey to collect data from qualified endocrinologists. The survey included a case report form to capture patient medical chart data and a web-enabled questionnaire to capture practitioner-level data pertaining to endocrinologists' perceptions of disease burden, CS treatments, and treatment attributes. RESULTS: Sixty-nine endocrinologists abstracted data from 273 unique medical charts of patients with CS. Mean patient age was 46.5 ± 13.4 years, with a 60:40 (female:male) gender split. The mean duration of endogenous CS amongst patients was 4.1 years. Chart data indicated that patients experienced a high burden of comorbidities and symptoms, including fatigue, weight gain, and muscle weakness despite multi-modal treatment. When evaluating treatments for CS, endocrinologists rated improvement in health-related quality of life (HRQoL) as the most important treatment attribute (mean score = 7.8; on a scale of 1 = Not at all important to 9 = Extremely important). Surgical intervention was the modality endocrinologists were most satisfied with, but they agreed that there was a significant unmet treatment need for patients with CS. CONCLUSION: Endocrinologists recognized that patients with CS suffered from a debilitating condition with a high symptomatic and HRQoL burden and reported that improvement in HRQoL was the key treatment attribute influencing their treatment choices. This study highlights unmet needs for patients with CS. Patients with CS have a high rate of morbidity and comorbidity, even after treatment.


Assuntos
Síndrome de Cushing , Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Síndrome de Cushing/terapia , Síndrome de Cushing/diagnóstico , Endocrinologistas , Qualidade de Vida , Estudos Retrospectivos , Estudos Transversais
2.
Reprod Domest Anim ; 59(6): e14634, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38860761

RESUMO

The impact of beta-carotene on cattle fertility has been investigated in various studies; however, consensus on this issue has not been reached. In the present study, we systematically reviewed and meta-analysed 29 publications conducted between 1984 and 2022, focusing on seven fertility measures, clinical mastitis and milk yield in cows. We did not find statistically significant results in 8 out of 11 parameters (p > .05). Statistically significant results were observed for milk yield (MD: 216.25 kg in 305 days, p = .01, CI: 50.73-381.77), pregnancy at first service (OR: 1.38 CI: 1.08-1.76, p = .01) and clinical mastitis (OR: 0.59, CI: 0.44-0.80, p = .006) in favour of beta-carotene supplementation. The meta-regression revealed significant effects of 'plasma beta-carotene levels' on 'service to per pregnancy' and dose on 'milk yield' (p = .04 and p = 0). In binary outcomes, 'dose × day' and 'plasma beta-carotene concentration in the control group' positively influenced pregnancy at first service (p = .02 and .03). In conclusion, given the positive point direction observed for some variables and insignificant results for others, there is a need for more studies. We note the very high heterogeneity of outcomes and suggest caution in interpreting results.


Assuntos
Lactação , Mastite Bovina , Leite , beta Caroteno , Animais , beta Caroteno/administração & dosagem , Feminino , Bovinos , Leite/química , Gravidez , Suplementos Nutricionais , Fertilidade
3.
J Pharmacol Exp Ther ; 371(2): 476-486, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31110114

RESUMO

There is an unmet medical need for nonopioid pain therapies in human populations; several pathways are under investigation for possible therapeutic intervention. Tetrahydrobiopterin (BH4) has received attention recently as a mediator of neuropathic pain. Recent reports have implicated sepiapterin reductase (SPR) in this pain pathway as a regulator of BH4 production. To evaluate the role of SPR inhibition on BH4 reduction, we developed analytical methods to monitor the relationship between the plasma concentration of test article and endogenous pterins and applied these in the rat spinal nerve ligation pain model. Sepiapterin is an endogenous substrate, which accumulates upon inhibition of SPR. In response to a potent inhibitor of SPR, plasma concentrations of sepiapterin increased proportionally with exposure. An indirect-effect pharmacokinetic/pharmacodynamic model was developed to describe the relationship between the plasma pharmacokinetics of test article and plasma sepiapterin levels in the rat, which was used to determine an in vivo SPR IC50 value. SPR inhibition and mechanical allodynia were assessed coordinately with pterin biomarkers in plasma and at the site of neuronal injury (i.e., dorsal root ganglion). Upon daily oral administration for 3 consecutive days, unbound plasma concentrations of test article exceeded the unbound in vivo rat SPR IC90 throughout the dose intervals, leading to a 60% reduction in BH4 in the dorsal root ganglion. Despite evidence for pharmacological modulation of the BH4 pathway, there was no significant effect on the tactile paw withdrawal threshold relative to vehicle-treated controls.


Assuntos
Oxirredutases do Álcool/antagonistas & inibidores , Oxirredutases do Álcool/metabolismo , Hiperalgesia/metabolismo , Neuralgia/metabolismo , Medição da Dor/métodos , Animais , Biopterinas/análogos & derivados , Biopterinas/antagonistas & inibidores , Biopterinas/metabolismo , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Humanos , Hiperalgesia/tratamento farmacológico , Masculino , Neuralgia/tratamento farmacológico , Medição da Dor/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Tato/efeitos dos fármacos , Tato/fisiologia
4.
Telemed J E Health ; 25(1): 18-24, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29742036

RESUMO

BACKGROUND: Emergency departments (EDs) have recognized an increasing number of patients presenting with mental health (MH) concerns. This trend imposes greater demands upon EDs already operating at capacity. Many ED providers do not feel they are optimally prepared to provide the necessary MH care. One consideration in response to this dilemma is to use advanced telemedicine technology for psychiatric consultation. INTRODUCTION: We examined a rural- and community-based health system operating 21 EDs, none of which has direct access to psychiatric consultation. Dedicated beds to MH range from zero (in EDs with only 3 beds) to 6 (in an ED with 38 beds). MATERIALS AND METHODS: We conducted a needs assessment of this health system. This included a survey of emergency room providers with a 67% response rate and site visits to directly observe patient flow and communication with ED staff. A visioning workshop provided input from ED staff. Data were also obtained, which reflected ED admissions for the year 2015. RESULTS: The data provide a summary of provider concerns, a summary of MH presentations and diagnosis, and age groupings. The data also provide a time when most MH concerns present to the ED. DISCUSSION: Based upon these results, a proposed model for delivering comprehensive regional emergency telepsychiatry and behavioral health services is proposed. CONCLUSIONS: Emergency telepsychiatry services may be a tenable solution for addressing the shortage of psychiatric consultation to EDs in light of increasing demand for MH treatment in the ED.


Assuntos
Serviço Hospitalar de Emergência/organização & administração , Transtornos Mentais/terapia , Serviços de Saúde Mental/organização & administração , Consulta Remota/organização & administração , Serviços de Saúde Rural/organização & administração , Adolescente , Adulto , Idoso , Feminino , Acessibilidade aos Serviços de Saúde/organização & administração , Humanos , Masculino , Transtornos Mentais/epidemiologia , Pessoa de Meia-Idade , Avaliação das Necessidades , Psiquiatria/organização & administração , População Rural , Adulto Jovem
5.
Radiology ; 284(2): 530-540, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28387639

RESUMO

Purpose To assess the effect of intravenous contrast media on renal function in neonates. Materials and Methods Institutional review board approval was obtained with waiver of consent. Electronic health records from January 2011 to April 2013 were reviewed retrospectively. Measures of renal function were obtained in inpatient neonates who underwent magnetic resonance (MR) imaging or computed tomography (CT) and for whom serum creatinine (Cr) levels were obtained within 72 hours before imaging and at least one time after imaging (>1 day after administration of contrast material). A total of 140 neonates who received contrast material (59 who underwent CT with iohexol or iodixanol and 81 who underwent MR imaging with gadopentetate dimeglumine) were identified. These neonates were frequency matched according to sex, gestational and postnatal age, and preimaging serum Cr levels with neonates who underwent unenhanced MR imaging or CT. Cr levels and glomerular filtration rates (GFRs) were grouped according to when they were obtained (before imaging, 1-2 days after imaging, 3-5 days after imaging, 6-9 days after imaging, 10-45 days after imaging, and more than 45 days after imaging). Serum Cr levels and GFRs for each time period were compared between groups by using hierarchic regressions or χ2 or Fisher exact tests and with repeated-measures analysis of variance to compare groups on the rate of change in serum Cr levels and GFRs from before to after imaging. Results Cr levels decreased and GFRs increased in both groups from before to after imaging (CT group, P ≤ .01; MR imaging group, P ≤ .01). The neonates who underwent contrast material-enhanced imaging and the neonates who underwent unenhanced imaging showed similar serum Cr levels at all examined time periods. Groups also did not differ in the proportion of neonates with serum Cr levels higher than the reference range (>0.4 mg/dL) at any time point (iodine- [P > .12] or gadolinium-based [P > .13] contrast material). Similar findings were observed for GFRs. None of the neonates developed nephrogenic systemic fibrosis. Conclusion In the absence of known renal failure, neonates receiving standard inpatient care do not appear to be at increased risk for developing renal toxicity due to administration of intravenous iodine- and gadolinium-based contrast material. © RSNA, 2017.


Assuntos
Meios de Contraste/administração & dosagem , Creatinina/sangue , Nefropatias/sangue , Nefropatias/induzido quimicamente , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , Administração Intravenosa , Meios de Contraste/efeitos adversos , Feminino , Gadolínio DTPA/administração & dosagem , Gadolínio DTPA/efeitos adversos , Taxa de Filtração Glomerular/efeitos dos fármacos , Humanos , Recém-Nascido , Iohexol/administração & dosagem , Iohexol/efeitos adversos , Masculino , Estudos Retrospectivos , Fatores de Risco , Ácidos Tri-Iodobenzoicos/administração & dosagem , Ácidos Tri-Iodobenzoicos/efeitos adversos
6.
FASEB J ; 30(1): 102-10, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26316271

RESUMO

Stability of endothelial cell (EC) adherens junctions (AJs) is central for prevention of tissue edema, the hallmark of chronic inflammatory diseases including acute respiratory distress syndrome. Here, we demonstrate a previously unsuspected role of sphingosine kinase 1 (SPHK1) in the mechanism by which transient receptor potential channel 1 (Trpc1)-mediated Ca(2+) entry destabilizes AJs. Trpc1(-/-) monolayers showed a 2.2-fold increase in vascular endothelial (VE)-cadherin cell-surface expression above wild-type (WT) monolayers. Thrombin increased endothelial permeability (evident by a 5-fold increase in interendothelial gap area and 60% decrease in transendothelial electrical resistance) in WT but not Trpc1(-/-) ECs. Trpc1(-/-) mice resisted the hyperpermeability effects of the edemagenic agonists used and exhibited 60% less endotoxin-induced mortality. Because sphingosine-1-phosphate (S1P) strengthens AJs, we determined if TRPC1 functioned by inhibiting SPHK1 activity, which generates S1P. Intriguingly, Trpc1(-/-) ECs or ECs transducing a TRPC1-inactive mutant showed a 1.5-fold increase in basal SPHK1 expression compared with WT ECs, resulting in a 2-fold higher S1P level. SPHK1 inhibitor SK1-I decreased basal transendothelial electrical resistance more in WT ECs (48 and 72% reduction at 20 and 50 µM, respectively) than in Trpc1(-/-) ECs. However, SK1-I pretreatment rescued thrombin-induced EC permeability in Trpc1(-/-) ECs. Thus, TRPC1 suppression of basal SPHK1 activity enables EC-barrier destabilization by edemagenic agonists.


Assuntos
Junções Aderentes/metabolismo , Células Endoteliais/metabolismo , Endotélio/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Canais de Cátion TRPC/metabolismo , Animais , Caderinas/metabolismo , Cálcio/metabolismo , Permeabilidade da Membrana Celular , Camundongos Knockout , Transdução de Sinais/fisiologia , Canais de Cátion TRPC/genética
7.
J Am Soc Nephrol ; 27(11): 3308-3319, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27020855

RESUMO

Gain-of-function mutations of classic transient receptor potential channel 6 (TRPC6) were identified in familial FSGS, and increased expression of wild-type TRPC6 in glomeruli is observed in several human acquired proteinuric diseases. Synaptopodin, an actin binding protein that is important in maintaining podocyte function, is downregulated in various glomerular diseases. Here, we investigated whether synaptopodin maintains podocyte function by regulating podocyte surface expression and activity of TRPC6. We show indirect interaction and nonrandom association of synaptopodin and TRPC6 in podocytes. Knockdown of synaptopodin in cultured mouse podocytes increased the expression of TRPC6 at the plasma membrane, whereas overexpression of synaptopodin decreased it. Mechanistically, synaptopodin-dependent TRPC6 surface expression required functional actin and microtubule cytoskeletons. Overexpression of wild-type or FSGS-inducing mutant TRPC6 in synaptopodin-depleted podocytes enhanced TRPC6-mediated calcium influx and induced apoptosis. In vivo, knockdown of synaptopodin also caused increased podocyte surface expression of TRPC6. Administration of cyclosporin A, which stabilizes synaptopodin, reduced LPS-induced proteinuria significantly in wild-type mice but to a lesser extent in TRPC6 knockout mice. Furthermore, administration of cyclosporin A reversed the LPS-induced increase in podocyte surface expression of TRPC6 in wild-type mice. Our findings suggest that alteration in synaptopodin levels under disease conditions may modify intracellular TRPC6 channel localization and activity, which further contribute to podocyte dysfunction. Reducing TRPC6 surface levels may be a new approach to restoring podocyte function.


Assuntos
Proteínas dos Microfilamentos/fisiologia , Podócitos/metabolismo , Proteinúria/metabolismo , Canais de Cátion TRPC/biossíntese , Animais , Membrana Celular/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Podócitos/ultraestrutura , Canal de Cátion TRPC6
8.
Pediatr Blood Cancer ; 63(3): 493-8, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26579879

RESUMO

BACKGROUND: The combination of topotecan and cyclophosphamide is active in relapsed Ewing sarcoma family of tumors (ESFT). The feasibility of adding these agents combined with vincristine (vincristine-topotecan-cyclophosphamide [VTc]) to standard five-drug chemotherapy with vincristine-doxorubicin-cyclophosphamide (VDC) and ifosfamide-etoposide (IE) administered in an interval-compressed (2-week instead of 3-week intervals) schedule was investigated. PROCEDURE: Newly diagnosed patients with localized ESFT < 31 years, with good performance status and adequate organ function were eligible. Seventeen alternating cycles of chemotherapy with VTc, VDC, and IE were administered at 2-week intervals. Local control (LC) of the primary tumor occurred following six cycles. Primary endpoints were the ability to deliver chemotherapy in an interval-compressed schedule, and the rate of grade 3 or greater nonhematologic toxicity and grade 4 hematologic toxicity, which delayed chemotherapy by ≥2 weeks. Secondary endpoints were event-free survival (EFS) and overall survival (OS). RESULTS: Thirty-five patients with a median age of 11 years were enrolled. The mean time to last dose of chemotherapy prior to LC was 12.6 ± 1.4 weeks and 45.5% of patients received intended chemotherapy without any delay prior to LC. There were no toxic deaths or unexpected toxicities. Five-year EFS was 79.6% (95% confidence interval [CI]: 61.8-89.7%) and 5-year OS was 88% (95% CI: 71.4-95.3%). CONCLUSIONS: The addition of VTc to standard therapy was tolerable with sufficient interval compression compared to historical standard 3-week cycles.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Ciclofosfamida/administração & dosagem , Sarcoma de Ewing/tratamento farmacológico , Vincristina/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/toxicidade , Criança , Doxorrubicina/administração & dosagem , Esquema de Medicação , Etoposídeo/administração & dosagem , Feminino , Humanos , Ifosfamida/administração & dosagem , Masculino , Projetos Piloto , Neoplasias de Tecidos Moles/tratamento farmacológico , Topotecan/administração & dosagem
9.
Cancer ; 121(3): 467-75, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25251206

RESUMO

BACKGROUND: Patients with Ewing sarcoma require local primary tumor control with surgery, radiation, or both. The optimal choice of local control for overall and local disease control remains unclear. METHODS: Patients with localized Ewing sarcoma of bone who were treated on 3 consecutive protocols with standard-dose, 5-drug chemotherapy every 3 weeks were included (n=465). Propensity scores were used to control for differences between local control groups by constructing multivariate models to assess the impact of local control type on clinical endpoints (event-free survival [EFS], overall survival, local failure, and distant failure) independent of differences in their propensity to receive each local control type. RESULTS: Patients who underwent surgery were younger (P=.02) and had more appendicular tumors (P<.001). Compared with surgery, radiation had higher unadjusted risks of any event (hazard ratio [HR], 1.70; 95% confidence interval [CI], 1.18-2.44), death (HR, 1.84; 95% CI, 1.18-2.85), and local failure (HR, 2.57; 95% CI, 1.37-4.83). On multivariate analysis, compared with surgery, radiation had a higher risk of local failure (HR, 2.41; 95% CI, 1.24-4.68), although there were no significant differences in EFS (HR, 1.42; 95% CI, 0.94-2.14), overall survival (HR, 1.37; 95% CI, 0.83-2.26), or distant failure (HR, 1.13; 95% CI, 0.70-1.84) between local control groups. CONCLUSIONS: In this large group of similarly treated patients, choice of the mode of local control was not related significantly to EFS, overall survival, or distant failure, although the risk of local failure was greater for radiation compared with surgery. These data support surgical resection when appropriate, whereas radiotherapy remains a reasonable alternative in selected patients.


Assuntos
Neoplasias Ósseas/terapia , Sarcoma de Ewing/terapia , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/radioterapia , Neoplasias Ósseas/cirurgia , Criança , Estudos de Coortes , Feminino , Humanos , Masculino , Análise Multivariada , Ensaios Clínicos Controlados Aleatórios como Assunto , Sarcoma de Ewing/tratamento farmacológico , Sarcoma de Ewing/radioterapia , Sarcoma de Ewing/cirurgia
10.
Anaerobe ; 28: 104-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24930431

RESUMO

Periodontal disease is a common disease of dogs and cats often requiring antimicrobial treatment as an adjunct to mechanical debridement. However, correct compliance with oral antimicrobial therapy in companion animals is often difficult. Cefovecin is a recently introduced veterinary cephalosporin that has demonstrated prolonged concentrations in extracellular fluid, allowing for dosing intervals of up to 14 days. Subgingival samples were collected from the oral cavity of 29 dogs and eight cats exhibiting grade 2 or grade 3 periodontal disease. Samples were cultivated on Wilkin Chalgrens agar and incubated in an anaerobic chamber for seven days. Selected anaerobic bacteria were isolated and identified to species level using 16S rRNA gene sequence analysis. Minimum inhibitory concentrations were determined for cefovecin and six additional antimicrobials using the agar dilution methodology recommended by the Clinical and Laboratory Standards Institute. The 65 clinical isolates were identified as Porphyromonas gulae (n = 45), Porphyromonas crevioricanis (n = 12), Porphyromonas macacae (n = 1), Porphyromonas cangingivalis (n = 1) Fusobacterium nucleatum (n = 2), Fusobacterium russii (n = 1) and Solobacterium moorei (n = 3). This is the first report of S. moorei being isolated from companion animals with periodontal disease. All isolates were highly susceptible to cefovecin, with a MIC90 of ≤0.125 µg/ml. Conversely, different resistance rates to ampicillin, amoxicillin and erythromycin between isolates were detected. Cefovecin is thus shown to be effective in vitro against anaerobic bacteria isolated from dogs and cats with periodontal disease.


Assuntos
Antibacterianos/farmacologia , Bactérias Anaeróbias/efeitos dos fármacos , Bactérias Anaeróbias/isolamento & purificação , Doenças do Gato/microbiologia , Cefalosporinas/farmacologia , Doenças do Cão/microbiologia , Doenças Periodontais/veterinária , Animais , Bactérias Anaeróbias/classificação , Gatos , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Placa Dentária/microbiologia , Cães , Testes de Sensibilidade Microbiana , Doenças Periodontais/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
11.
Radiology ; 269(1): 198-207, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23696684

RESUMO

PURPOSE: To validate a multicenter protocol that examines lower extremity skeletal muscles of children with Duchenne muscular dystrophy (DMD) by using magnetic resonance (MR) imaging and MR spectroscopy in terms of reproducibility of these measurements within and across centers. MATERIALS AND METHODS: This HIPAA-compliant study was approved by the institutional review boards of all participating centers, and informed consent was obtained from each participant or a guardian. Standardized procedures with MR operator training and quality assurance assessments were implemented, and data were acquired at three centers by using different 3-T MR imaging instruments. Measures of maximal cross-sectional area (CSAmax), transverse relaxation time constant (T2), and lipid fraction were compared among centers in two-compartment coaxial phantoms and in two unaffected adult subjects who visited each center. Also, repeat MR measures were acquired twice on separate days in 30 boys with DMD (10 per center) and 10 unaffected boys. Coefficients of variation (CVs) were computed to examine the repeated-measure variabilities within and across centers. RESULTS: CSAmax, T2 from MR imaging and MR spectroscopy, and lipid fraction were consistent across centers in the phantom (CV, <3%) and in the adult subjects who traveled to each site (CV, 2%-7%). High day-to-day reproducibility in MR measures was observed in boys with DMD (CSAmax, CV = 3.7% [25th percentile, 1.3%; 75th percentile, 5.1%]; contractile area, CV = 4.2% [25th percentile, 0.8%; 75th percentile, 4.9%]; MR imaging T2, CV = 3.1% [25th percentile, 1.2%; 75th percentile, 4.7%]; MR spectroscopy T2, CV = 3.9% [25th percentile, 1.5%; 75th percentile, 5.1%]; and lipid fraction, CV = 4.7% [25th percentile, 1.0%; 75th percentile, 5.3%]). CONCLUSION: The MR protocol implemented in this multicenter study achieved highly reproducible measures of lower extremity muscles across centers and from day to day in ambulatory boys with DMD.


Assuntos
Lipídeos/análise , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/metabolismo , Distrofia Muscular de Duchenne/patologia , Adolescente , Adulto , Biomarcadores/análise , Criança , Pré-Escolar , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estados Unidos
12.
J Biol Chem ; 286(15): 13414-22, 2011 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-21343294

RESUMO

Single-channel conductance in Cys-loop channels is controlled by the nature of the amino acids in the narrowest parts of the ion conduction pathway, namely the second transmembrane domain (M2) and the intracellular helix. In cationic channels, such as Torpedo ACh nicotinic receptors, conductance is increased by negatively charged residues exposed to the extracellular vestibule. We now show that positively charged residues at the same loop 5 position boost also the conductance of anionic Cys-loop channels, such as glycine (α1 and α1ß) and GABA(A) (α1ß2γ2) receptors. Charge reversal mutations here produce a greater decrease on outward conductance, but their effect strongly depends on which subunit carries the mutation. In the glycine α1ß receptor, replacing Lys with Glu in α1 reduces single-channel conductance by 41%, but has no effect in the ß subunit. By expressing concatameric receptors with constrained stoichiometry, we show that this asymmetry is not explained by the subunit copy number. A similar pattern is observed in the α1ß2γ2 GABA(A) receptor, where only mutations in α1 or ß2 decreased conductance (to different extents). In both glycine and GABA receptors, the effect of mutations in different subunits does not sum linearly: mutations that had no detectable effect in isolation did enhance the effect of mutations carried by other subunits. As in the nicotinic receptor, charged residues in the extracellular vestibule of anionic Cys-loop channels influence elementary conductance. The size of this effect strongly depends on the direction of the ion flow and, unexpectedly, on the nature of the subunit that carries the residue.


Assuntos
Subunidades Proteicas/metabolismo , Receptores de GABA-A/metabolismo , Substituição de Aminoácidos , Animais , Glicina , Células HEK293 , Humanos , Mutação de Sentido Incorreto , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Subunidades Proteicas/genética , Receptores de GABA-A/genética , Xenopus laevis
13.
Equine Vet J ; 54(3): 457-466, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34428330

RESUMO

BACKGROUND: Accuracy of baseline ACTH for the diagnosis of PPID in horses varies between studies. OBJECTIVES: To estimate the diagnostic accuracy of ACTH as a biomarker for PPID in adult horses and appraise potential causes of heterogeneity. STUDY DESIGN: Systematic review and meta-analysis. METHODS: A literature review identified studies reporting diagnostic accuracy data for extraction. Risk of bias was evaluated using QUADAS-2. Two random-effects models, the hierarchical summary receiver operating curve (HSROC) and the bivariate binomial normal model (BBN) were used to pool accuracy measurements. We performed meta-regression using study-level variables. The impact of diagnostic test accuracy on the frequency of false-positive and false-negative results at various pretest probabilities was calculated using the BBN model's accuracy results. RESULTS: Patient selection and index test evaluation demonstrated significant risk of bias. Mean and 95% confidence intervals for sensitivity and specificity for all studies (n = 11) based upon the HSROC model were (0.72, 95% CI: 0.62 to 0.82) and (0.88, 95% CI: 0.79 to 0.93), respectively. When studies with a common positivity threshold of 35 pg/mL ACTH were evaluated (n = 6), sensitivity and specificity were (0.66, 95% CI:0.54 to 0.77) and (0.87, 95% CI: 0.74 to 0.94). In a hypothetical group of one thousand horses with PPID prevalence of 2%, 20%, and 90%, the frequency of resulting false-positive and false-negatives would be (127 and 7), (104 and 68) and (13 and 306), respectively. Factors leading to increased accuracy were case-control design, clinical reference standard and data-driven choice of ACTH threshold. MAIN LIMITATIONS: A small number of primary studies (n = 11) were available, demonstrating significant biases. CONCLUSIONS: Less biased studies examining diagnostic accuracy of ACTH are needed. In horses with a high pretest probability of PPID, ACTH may be a functional "rule-in" test. Baseline ACTH is not recommended for screening purposes or use in horses without clinical signs of PPID.


Assuntos
Doenças dos Cavalos , Doenças da Hipófise , Adeno-Hipófise Parte Intermédia , Hormônio Adrenocorticotrópico , Animais , Biomarcadores , Doenças dos Cavalos/diagnóstico , Cavalos , Doenças da Hipófise/diagnóstico , Doenças da Hipófise/veterinária , Prevalência
14.
Sci Rep ; 11(1): 10256, 2021 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-33986433

RESUMO

N-type voltage-gated calcium channels (CaV2.2) are predominantly expressed at presynaptic terminals, and their function is regulated by auxiliary α2δ and ß subunits. All four mammalian α2δ subunits enhance calcium currents through CaV1 and CaV2 channels, and this increase is attributed, in part, to increased CaV expression at the plasma membrane. In the present study we provide evidence that α2δ-1, like α2δ-2, is recycled to the plasma membrane through a Rab11a-dependent endosomal recycling pathway. Using a dominant-negative Rab11a mutant, Rab11a(S25N), we show that α2δ-1 increases plasma membrane CaV2.2 expression by increasing the rate and extent of net forward CaV2.2 trafficking in a Rab11a-dependent manner. Dominant-negative Rab11a also reduces the ability of α2δ-1 to increase CaV2.2 expression on the cell-surface of hippocampal neurites. In contrast, α2δ-3 does not enhance rapid forward CaV2.2 trafficking, regardless of whether Rab11a(S25N) is present. In addition, whole-cell CaV2.2 currents are reduced by co-expression of Rab11a(S25N) in the presence of α2δ-1, but not α2δ-3. Taken together these data suggest that α2δ subtypes participate in distinct trafficking pathways which in turn influence the localisation and function of CaV2.2.


Assuntos
Canais de Cálcio Tipo L/metabolismo , Canais de Cálcio/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Animais , Encéfalo/metabolismo , Cálcio/metabolismo , Canais de Cálcio/genética , Canais de Cálcio/fisiologia , Canais de Cálcio Tipo L/genética , Canais de Cálcio Tipo N/genética , Canais de Cálcio Tipo N/metabolismo , Linhagem Celular , Membrana Celular/metabolismo , Ácidos Cicloexanocarboxílicos/metabolismo , Gabapentina/metabolismo , Hipocampo/metabolismo , Neuritos/metabolismo , Neurônios/metabolismo , Terminações Pré-Sinápticas/metabolismo , Cultura Primária de Células , Transporte Proteico , Ratos , Ácido gama-Aminobutírico/metabolismo , Proteínas rab de Ligação ao GTP/genética
15.
J Immunother Cancer ; 9(9)2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34531247

RESUMO

BACKGROUND: We describe intratumoral injection of a slow-release emulsion of killed mycobacteria (complete Freund's adjuvant (CFA)) in three preclinical species and in human cancer patients. METHODS: Efficacy and safety were tested in mammary tumors in mice, in mastocytomas in mice and dogs, and in equine melanomas. In mice, survival, tumor growth, and tumor infiltration by six immune cell subsets (by flow cytometry) were investigated and analyzed using Cox proportional hazards, a random slopes model, and a full factorial model, respectively. Tumor growth and histology were investigated in dogs and horses, as well as survival and tumor immunohistochemistry in dogs. Tumor biopsies were taken from human cancer patients on day 5 (all patients) and day 28 (some patients) of treatment and analyzed by histology. CT scans are provided from one patient. RESULTS: Significantly extended survival was observed in mouse P815 and 4T1 tumor models. Complete tumor regressions were observed in all three non-human species (6/186 (3%) of mouse mastocytomas; 3/14 (21%) of canine mastocytomas and 2/11 (18%) of equine melanomas). Evidence of systemic immune responses (regression of non-injected metastases) was also observed. Analysis of immune cells infiltrating mastocytoma tumors in mice showed that early neutrophil infiltration was predictive of treatment benefit. Analysis of the site of mastocytoma regression in dogs weeks or months after treatment demonstrated increased B and T cell infiltrates. Thus, activation of the innate immune system alone may be sufficient for regression of some injected tumors, followed by activation of the acquired immune system which can mediate regression of non-injected metastases. Finally, we report on the use of CFA in 12 human cancer patients. Treatment was well tolerated. CT scans showing tumor regression in a patient with late-stage renal cancer are provided. CONCLUSION: Our data demonstrate that intratumoral injection of CFA has major antitumor effects in a proportion of treated animals and is safe for use in human cancer patients. Further trials in human cancer patients are therefore warranted. Our novel treatment provides a simple and inexpensive cancer immunotherapy, immediately applicable to a wide range of solid tumors, and is suitable to patients in developing countries and advanced care settings.


Assuntos
Imunoterapia/métodos , Neoplasias/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Cães , Feminino , Cavalos , Humanos , Masculino , Camundongos
16.
Am J Physiol Regul Integr Comp Physiol ; 299(3): R960-7, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20554933

RESUMO

Postprandial hypotension occurs frequently and is associated with increased morbidity. Gastric distension may attenuate the postprandial fall in blood pressure (BP). Using a barostat, we sought to determine the effects of gastric distension on BP, heart rate (HR), and superior mesenteric artery (SMA) blood flow responses to intraduodenal glucose in eight (6 men, 2 women) healthy older (65-75 yr old) subjects. BP and HR were measured using an automated device and SMA blood flow was measured using Doppler ultrasound on 4 days in random order. SMA blood flow was calculated using the radius of the SMA and time-averaged mean velocity. Subjects were intubated with a nasoduodenal catheter incorporating a duodenal infusion port. On 2 of the 4 days, they were intubated orally with a second catheter, incorporating a barostat bag, positioned in the fundus and set at 8 mmHg above minimal distending pressure. Each subject received a 60-min (0-60 min) intraduodenal infusion of glucose (3 kcal/min) or saline (0.9%); therefore, the four study conditions were as follows: intraduodenal glucose + barostat (glucose + distension), intraduodenal saline + barostat (saline + distension), intraduodenal glucose (glucose), and intraduodenal saline (saline). Systolic and diastolic BP fell during glucose compared with saline (P = 0.05 and P = 0.003, respectively) and glucose + distension (P = 0.01 and P = 0.05, respectively) and increased during saline + distension compared with saline (P = 0.04 and P = 0.006, respectively). The maximum changes in systolic BP were -14 +/- 5, +11 +/- 2, -3 +/- 4, and +15 +/- 3 mmHg for glucose, saline, glucose + distension, and saline + distension, respectively. There was an increase in HR during glucose and glucose + distension (maximum rise = 14 +/- 2 and 14 +/- 3 beats/min, respectively), but not during saline or saline + distension. SMA blood flow increased during glucose and glucose + distension (2,388 +/- 365 and 1,673 +/- 187 ml/min, respectively), but not during saline, and tended to decrease during saline + distension (821 +/- 115 and 864 +/- 116 ml/min, respectively). In conclusion, gastric distension has the capacity to abolish the fall in BP and attenuate the rise in SMA blood flow induced by intraduodenal glucose in healthy older subjects.


Assuntos
Pressão Sanguínea/fisiologia , Glucose/farmacologia , Artéria Mesentérica Superior/fisiologia , Pressão , Estômago/fisiologia , Idoso , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea/efeitos dos fármacos , Duodeno/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Edulcorantes/farmacologia
17.
Chem Res Toxicol ; 23(6): 1025-33, 2010 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-20521778

RESUMO

The key to the discovery of new pharmaceuticals is to develop molecules that interact with the intended target and minimize interaction with unintended molecular targets, therefore minimizing toxicity. This is aided by the use of various in vitro selectivity assays that are used to select agents most potent for the desired target. Typically, molecules from similar chemical series, with similar in vitro potencies, are expected to yield comparable in vivo pharmacological and toxicological profiles, predictive of target effects. However, in this study, we investigated the in vivo effects of two analogue compounds that similarly inhibit several receptor tyrosine kinases such as vascular endothelial growth factor receptor 1 (VEGFR/Flt1), vascular endothelial growth factor 2 (VEGFR2/kinase domain receptor/Flk-1), vascular endothelial growth factor receptor 3 (VEGFR3/Flt4), platelet-derived growth factor receptor (PDGFR), and Kit receptors, which bear similar chemical structures, have comparable potencies, but differ markedly in their rodent toxicity profiles. Global gene expression data were used to generate hypotheses regarding the existence of toxicity triggers that would reflect the perturbation of signaling in multiple organs such as the liver, adrenal glands, and the pancreas in response to compound treatment. We concluded that differences in pharmacokinetic properties of the two analogues, such as volume of distribution, half-life, and organ concentrations, resulted in marked differences in the chemical burden on target organs and may have contributed to the vast differences in toxicity profiles observed with the two otherwise similar molecules. We propose including select toxicokinetic parameters such as V(ss), T(1/2), and T(max) as additional criteria that could be used to rank order compounds from the same pharmacological series to possibly minimize organ toxicity. Assessment of toxicokinetics is not an atypical activity on toxicology studies, even in early screening studies; however, these data may not always be used in decision making for selecting or eliminating one compound over another. Finally, we illustrate that in vivo gene expression profiles can serve as a complementary assessor of this activity and simultaneously help provide an assessment of on or off-target biological activity.


Assuntos
Expressão Gênica/efeitos dos fármacos , Inibidores de Proteínas Quinases/efeitos adversos , Inibidores de Proteínas Quinases/farmacocinética , Proteínas Proto-Oncogênicas c-kit/antagonistas & inibidores , Receptores do Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Genômica , Masculino , Inibidores de Proteínas Quinases/química , Ratos , Ratos Sprague-Dawley , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores
18.
J Med Econ ; 23(7): 744-750, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32162983

RESUMO

Research aim: To model the annual value of a novel ready-to-use, room-temperature stable liquid glucagon rescue pen and prefilled syringe (GRP, G-PFS; Xeris Pharmaceuticals, Inc.) for treatment of severe hypoglycemia events (SHE) versus current lyophilized powder glucagon emergency kits (GEK). GRP is a prefilled auto-injector designed to promptly administer concentrated liquid glucagon in a simple two-step process. G-PFS is a stable liquid formulation of glucagon in a prefilled syringe. In simulated emergencies, GRP and G-PFS demonstrated high functional efficacy, where 99% of users successfully administered a full-dose of drug. Studies with currently available injectable GEK suggest very low success rates (6-31%). The high functional efficacy of GRP and G-PFS significantly reduces user errors and may reduce utilization across emergency medical services (EMS), emergency departments (ED), and inpatient and outpatient costs for SHE.Methods: To estimate the economic impact of GRP and G-PFS, we developed a one-year budget impact model from a US commercial health plan perspective. Cost offsets from successful glucagon administration incorporated EMS, ED, inpatient, and outpatient utilization. Diabetes prevalence and event probabilities were estimated from publicly-available sources and clinical expert opinion. Costs (US$) were obtained from the 2018 Medicare Fee Schedules and adjusted to represent commercial payer costs.Results: GRP and G-PFS led to fewer EMS, ED, inpatient, and outpatient costs compared to GEK and no kit, resulting in total per-patient SHE costs of $2,564, $3,606, and $3,849, respectively. Costs for 1 million covered lives were 8.2 million following the introduction of GRP and G-PFS compared to almost 9 million before GRP and G-PFS.Limitations: The model is limited by reliance on assumptions based on expert opinion for key variables, primarily the probability of: (1) ambulance calls, (2) ambulance transport to the ED, and (3) non-ambulance transport to the ED.Conclusions: A budget impact model suggests GRP and G-PFS can lead to significant annual cost savings for US commercial payers.


Assuntos
Orçamentos , Redução de Custos , Formas de Dosagem , Glucagon/administração & dosagem , Glucagon/economia , Custos de Cuidados de Saúde , Hormônios/administração & dosagem , Hipoglicemia/tratamento farmacológico , Hipoglicemia/fisiopatologia , Seguradoras/economia , Bases de Dados Factuais , Custos de Cuidados de Saúde/estatística & dados numéricos , Humanos , Modelos Econômicos , Índice de Gravidade de Doença , Estados Unidos
19.
ChemSusChem ; 13(17): 4557-4566, 2020 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-32413243

RESUMO

Many valorization approaches for lignin rely on its organic solvent (organosolv) extraction. However, the severity of the extraction conditions required to obtain high lignin extraction generally results in low-quality lignin for downstream processing. To better understand the secondary reaction pathways and kinetics related to molecular alterations that result from organosolv extraction under extreme conditions, extractions were conducted at temperatures of 150, 180, and 210 °C. Lignin was collected at residence times between 0.25 and 18 h and analyzed by NMR techniques to quantify the concentrations of key chemical moieties that appear or disappear upon reactions of lignin molecules during and after their fractionation from biomass. The kinetics of chemical moiety evolution was modeled as processes in-series. In these models, pseudo first-order kinetics were used to describe the change in concentration of chemical moieties on extracted lignin as a function of residence time.

20.
Am J Physiol Regul Integr Comp Physiol ; 297(3): R716-22, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19553500

RESUMO

Postprandial hypotension occurs frequently, particularly in the elderly. The magnitude of the fall in blood pressure (BP) and rise in heart rate (HR) in response to enteral glucose are greater when gastric emptying (GE) or small intestinal infusion are more rapid. Meal ingestion is associated with an increase in splanchnic blood flow. In contrast, gastric distension may attenuate the postprandial fall in BP. The aims of this study were to evaluate, in older subjects, the comparative effects of intraduodenal glucose infusion, at a rate similar to GE of oral glucose, on BP, HR, superior mesenteric artery (SMA) flow, and blood glucose. Eight healthy subjects (5 men, 3 women, age 66-75 yr) were studied on two occasions. On day 1, each subject ingested 300 ml of water containing 75 g glucose. GE was quantified by three-dimensional ultrasonography between time t = 0-120 min, and the rate of emptying (kcal/min) was calculated. On day 2, glucose was infused intraduodenally at the same rate as that on day 1. On both days, BP, HR, SMA flow, and blood glucose were measured. The mean GE of oral glucose was 1.3 +/- 0.1 kcal/min. Systolic BP (P < 0.01), SMA flow (P < 0.05), and blood glucose (P < 0.01) were greater and HR less (P < 0.01) after oral, compared with intraduodenal, glucose. There were comparable falls in diastolic BP during the study days (P < 0.01 for both). We conclude that the magnitude of the fall in systolic BP and rise in HR are less after oral, compared with intraduodenal, glucose, presumably reflecting the "protective" effect of gastric distension.


Assuntos
Pressão Sanguínea , Glucose/administração & dosagem , Frequência Cardíaca , Hipotensão/fisiopatologia , Circulação Esplâncnica , Administração Oral , Fatores Etários , Idoso , Glicemia/metabolismo , Duodeno , Feminino , Esvaziamento Gástrico , Glucose/metabolismo , Humanos , Hipotensão/induzido quimicamente , Hipotensão/diagnóstico por imagem , Intubação Gastrointestinal , Masculino , Artérias Mesentéricas/diagnóstico por imagem , Artérias Mesentéricas/fisiopatologia , Período Pós-Prandial , Valores de Referência , Fluxo Sanguíneo Regional , Fatores de Tempo , Ultrassonografia Doppler Dupla
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