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1.
Cancers (Basel) ; 15(12)2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37370789

RESUMO

Breast cancer alone accounts for the majority of cancer deaths among women, with the most commonly diagnosed subtype being estrogen receptor positive (ER+). Survival has greatly improved for patients with ER+ breast cancer, due in part to the development of antiestrogen compounds, such as tamoxifen. While treatment of the primary disease is often successful, as many as 30% of patients will experience recurrence and metastasis, mainly due to developed endocrine therapy resistance. In this study, we discovered two tamoxifen combination therapies, with simeprevir and VX-680, that reduce the tumor burden in animal models of ER+ breast cancer more than either compound or tamoxifen alone. Additionally, these tamoxifen combinations reduced the expression of HER2, a hallmark of tamoxifen treatment, which can facilitate acquisition of a treatment-resistant phenotype. These combinations could provide clinical benefit by potentiating tamoxifen treatment in ER+ breast cancer.

2.
Cancers (Basel) ; 15(5)2023 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-36900375

RESUMO

Basal-like triple-negative breast cancer (TNBC) tumor cells are difficult to eliminate due to resistance mechanisms that promote survival. While this breast cancer subtype has low PIK3CA mutation rates when compared to estrogen receptor-positive (ER+) breast cancers, most basal-like TNBCs have an overactive PI3K pathway due to gene amplification or high gene expression. BYL-719 is a PIK3CA inhibitor that has been found to have low drug-drug interactions, which increases the likelihood that it could be useful for combinatorial therapy. Alpelisib (BYL-719) with fulvestrant was recently approved for treating ER+ breast cancer patients whose cancer had developed resistance to ER-targeting therapy. In these studies, a set of basal-like patient-derived xenograft (PDX) models was transcriptionally defined with bulk and single-cell RNA-sequencing and clinically actionable mutation profiles defined with Oncomine mutational profiling. This information was overlaid onto therapeutic drug screening results. BYL-719-based, synergistic two-drug combinations were identified with 20 different compounds, including everolimus, afatinib, and dronedarone, which were also found to be effective at minimizing tumor growth. These data support the use of these drug combinations towards cancers with activating PIK3CA mutations/gene amplifications or PTEN deficient/PI3K overactive pathways.

3.
J Mol Diagn ; 25(2): 69-86, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36503149

RESUMO

To assess the clinical implementation of the 2017 Standards and Guidelines for the Interpretation and Reporting of Sequence Variants in Cancer: A Joint Consensus Recommendation of the Association for Molecular Pathology, American Society of Clinical Oncology, and College of American Pathologists, identify content that may result in classification inconsistencies, and evaluate implementation barriers, an Association for Molecular Pathology Working Group conducted variant interpretation challenges and a guideline implementation survey. A total of 134 participants participated in the variant interpretation challenges, consisting of 11 variants in four cancer cases. Results demonstrate 86% (range, 54% to 94%) of the respondents correctly classified clinically significant variants, variants of uncertain significance, and benign/likely benign variants; however, only 59% (range, 39% to 84%) of responses agreed with the working group's consensus intended responses regarding both tiers and categories of clinical significance. In the implementation survey, 71% (157/220) of respondents have implemented the 2017 guidelines for variant classification and reporting either with or without modifications. Collectively, this study demonstrates that, although they may not yet be optimized, the 2017 guideline recommendations are being adopted for standardized somatic variant classification. The working group identified significant areas for future guideline improvement, including the need for a more granular and comprehensive classification system and education resources to meet the growing needs of both laboratory professionals and medical oncologists.


Assuntos
Neoplasias , Patologia Molecular , Humanos , Estados Unidos , Patologistas , Neoplasias/diagnóstico , Neoplasias/genética , Sequenciamento de Nucleotídeos em Larga Escala , Oncologia
4.
Diagn Cytopathol ; 51(1): 83-94, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36345929

RESUMO

Molecular diagnostics has expanded to become the standard of care for a variety of solid tumor types. With limited diagnostic material, it is often desirable to use cytological preparations to provide rapid and accurate molecular results. This review covers important pre-analytic considerations and limitations, and a description of common techniques that the modern cytopathologist should understand when ordering and interpreting molecular tests in practice.


Assuntos
Citologia , Técnicas de Diagnóstico Molecular , Humanos , Técnicas Citológicas
5.
Exp Clin Transplant ; 20(11): 1031-1034, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35297330

RESUMO

Graft-versus-host disease is an uncommon complication of solid-organ transplant and is associated with a high rate of mortality. Here, we describe a female patient with primary biliary cholangitis who developed graft-versus-host disease following an orthotopic liver and renal allotransplant from a deceased male donor. Systemic donor lymphoid chimerism is one of several important findings to confirm a diagnosis of graft-versus-host disease after solid-organ transplant, along with clinical and histologic findings. In this case, cytogenetic analyses and chimerism studies performed on blood, blood components, and bone marrow specimens obtained at several timepoints supported the diagnosis of graft-versus-host disease and demonstrated sustained near-complete donor engraftment of the lymphoid compartment. This case report illustrates the utility of chimerism testing to rapidly diagnose this serious condition in patients who have received a solid-organ transplant.


Assuntos
Doença Enxerto-Hospedeiro , Transplante de Órgãos , Humanos , Masculino , Feminino , Quimerismo , Resultado do Tratamento , Doença Enxerto-Hospedeiro/diagnóstico , Doença Enxerto-Hospedeiro/etiologia , Análise Citogenética
6.
Artigo em Inglês | MEDLINE | ID: mdl-31604779

RESUMO

Pediatric glioblastoma multiforme (GBM) has a poor prognosis as a result of recurrence after treatment of surgery and radiochemotherapy. A small subset of pediatric GBMs presenting with an ultra-high tumor mutational burden (TMB) may be sensitive to immune checkpoint inhibition. Here we report a 16-yr-old male with an ultra-hypermutated GBM. After incomplete surgical resection, molecular analysis of the tumor identified unusually high numbers of mutations and intratumor heterogeneity by a hotspot next-generation sequencing (NGS) panel. Further comprehensive molecular profiling identified a TMB of 343 mutations/Mb. An ultra-hypermutation genotype in pediatric GBMs is suggestive of a constitutive mismatch repair deficiency syndrome (CMMRD), which often acquires additional somatic driver mutations in replicating DNA polymerase genes. Tumor sequencing identified two MSH6 nonsense variants, a hotspot POLE mutation and a mutational signature supportive of a germline MMR deficiency with a somatic POLE mutation. However, constitutional testing identified only one nonsense MSH6 variant consistent with a Lynch syndrome diagnosis. This case represents the first confirmed Lynch syndrome case mimicking CMMRD by manifesting as an ultra-hypermutated pediatric GBM, following somatic mutations in MSH6 and POLE These findings permitted the patient's enrollment in an anti-PD-1 clinical trial for children with ultra-hypermutated GBM. Immunotherapy response has resulted in the patient's stable condition for over more than 1 year postdiagnosis.


Assuntos
Neoplasias Encefálicas/genética , Neoplasias Colorretais/genética , Reparo de Erro de Pareamento de DNA/genética , Glioblastoma/genética , Síndromes Neoplásicas Hereditárias/genética , Adolescente , Neoplasias Colorretais Hereditárias sem Polipose/genética , Reparo de Erro de Pareamento de DNA/fisiologia , Proteínas de Ligação a DNA/genética , Glioblastoma/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Mutação , Recidiva Local de Neoplasia/genética
8.
Surgery ; 165(6): 1199-1202, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31043235

RESUMO

BACKGROUND: To determine whether utilization of a retrieval bag during laparoscopic appendectomy for uncomplicated and complicated appendicitis (perforation/abscess) is associated with postoperative surgical site infection rates. METHODS: We studied patients presented in the database of the 2016 Appendectomy-Targeted American College of Surgeons National Surgical Quality Improvement Program who underwent laparoscopic appendectomy for pathology-confirmed appendicitis. The primary predictor variable was intraoperative utilization of a specimen retrieval bag for removal of the appendix from the peritoneal cavity. The primary outcome variable was 30-day postoperative surgical site infection. Logistic regression analysis was used to determine the association between use of a specimen retrieval bag and postoperative surgical site infection rate after adjustment for patient- and disease-related variables. RESULTS: A total of 10,357 patients were included for analysis. Of these procedures, 9,585 (92.6%) included the use of a specimen bag and 772 (7.5%) did not. The 30-day incidence of postoperative surgical site infection was 4.2% in the group in which no bag was used and 3.6% in the group in which a bag was used (adjusted odds ratio of surgical site infection with no bag utilization was 1.15 [95% confidence interval 0.78-1.69; P = .49]). The lack of a statistically significant association between bag utilization and postoperative surgical site infection incidence was also demonstrated for a subgroup of patients with perforated appendicitis. CONCLUSION: Utilization of a retrieval bag during laparoscopic appendectomy is not associated with a statistically significant decrease in postoperative surgical site infection for either uncomplicated or complicated acute appendicitis.


Assuntos
Apendicectomia/instrumentação , Apendicite/cirurgia , Laparoscopia/instrumentação , Manejo de Espécimes/instrumentação , Infecção da Ferida Cirúrgica/prevenção & controle , Adulto , Idoso , Idoso de 80 Anos ou mais , Apendicectomia/métodos , Apendicite/complicações , Feminino , Humanos , Laparoscopia/métodos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Manejo de Espécimes/métodos , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/etiologia , Resultado do Tratamento
9.
Genet Med ; 21(2): 426-430, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29875428

RESUMO

PURPOSE: The reclassification of genetic variants poses a significant challenge for laboratories and clinicians. Variant review has resulted in the reclassification of variants of unknown significance as well as the reclassification of previously established pathogenic and likely pathogenic variants. These reclassifications have the potential to alter the clinical management of patients with hereditary cancer syndromes. METHODS: Results were reviewed for 1694 patients seen for hereditary cancer evaluation between August 2012 and May 2017 to determine the frequency and types of variant reclassification. Patients with reclassifications with high potential for impact were monitored for alterations in organ surveillance, prophylactic surgery, and cascade testing. RESULTS: One hundred forty-two variants were reclassified representing 124/1694 (7.3%) patients; 11.3% of reclassifications (16/142) had a high potential for clinical impact with 94% (15/16) altering clinical management of patients with 56% (9/16) changing multiple areas of management. CONCLUSION: While reclassifications are rare, the impact on clinical management is profound. In many cases, patients with downgraded pathogenic/likely pathogenic variants had years of unnecessary organ surveillance and underwent unneeded surgical intervention. In addition, cascade testing misidentified those at risk for developing cancers, thereby altering the management across generations. The frequency and types of alterations to clinical management highlight the need for timely variant reclassification.


Assuntos
Genes Neoplásicos , Síndromes Neoplásicas Hereditárias/classificação , Síndromes Neoplásicas Hereditárias/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Variação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes Neoplásicas Hereditárias/genética , Adulto Jovem
10.
J Glob Oncol ; 4: 1-8, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30241169

RESUMO

PURPOSE: Cervical cancer is a leading cause of cancer-related mortality in low- and middle-income countries (LMICs) and screening in LMICs is extremely limited. We aimed to implement on-site high-risk human papillomavirus (hrHPV) DNA testing in cohorts of women from an urban factory and from a rural village. METHODS: A total of 802 women were recruited for this study in partnership with La Liga Contra el Cancer through the establishment of women's health resource fairs at two locations in Honduras: a textile factory (n = 401) in the city of San Pedro Sula and the rural village of El Rosario (n = 401) in Yoro. Participants received a routine cervical examination during which three sterile cytobrushes were used to collect cervical samples for testing. hrHPV genotyping was performed using a hrHPV genotyping assay and a real-time polymerase chain reaction instrument. RESULTS: hrHPV status across all participants at both sites was 13% hrHPV positive and 67% hrHPV negative. When hrHPV status was compared across all three testing sites, hrHPV-positive rates were approximately equal among the factory (13%), village (12%), and confirmatory testing at Dartmouth-Hitchcock Medical Center (Lebanon, NH; 14%). hrHPV genotype was compared across sites, with HPV16 showing the highest infection rate (15%), followed by HPV59 (12%), and HPV68 (11%). There was a low prevalence of HPV18 observed in both populations compared with the hrHPV-positive population in the United States. CONCLUSION: In collaboration with oncologists and pathologists from La Liga Contra el Cancer, we were able to provide a continuum of care once health-fair testing was performed. We established a method and implementation plan for hrHPV testing that is sustainable in LMICs.


Assuntos
Infecções por Papillomavirus/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Adulto , DNA Viral , Países em Desenvolvimento , Detecção Precoce de Câncer , Feminino , Genótipo , Humanos , Pessoa de Meia-Idade , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , Educação de Pacientes como Assunto , Projetos Piloto , Reação em Cadeia da Polimerase , Neoplasias do Colo do Útero/virologia
11.
Exp Mol Pathol ; 103(2): 172-177, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28822769

RESUMO

Advanced stage malignant melanoma often responds poorly to therapy with low survival rates. New therapeutic approaches are based upon a growing understanding of the underlying molecular abnormalities. We demonstrate the feasibility of a next generation sequencing (NGS) assay, which targets hotspots in 50 cancer genes, to assess genotypes that may influence therapeutic selection and response. DNA was extracted from formalin fixed paraffin embedded (FFPE) melanoma specimens to create multiplexed libraries which were sequenced. Of the 121 cases, BRAF mutations were present in 48 cases (40%) and NRAS mutations in 24 cases (20%). We identified other gene variants in 20 BRAF-mutated cases. Additional gene variants were also identified in the 57 BRAF wild-type cases. Four patients harbored different gene mutations at metastatic sites as compared to their primary lesions or metastasis from different sites. Concurrent gene variants may provide additional targets for future therapies and may suggest alternative mechanisms of secondary resistance.


Assuntos
Biomarcadores Tumorais/genética , Análise Mutacional de DNA/métodos , GTP Fosfo-Hidrolases/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Melanoma/diagnóstico , Proteínas de Membrana/genética , Mutação , Proteínas Proto-Oncogênicas B-raf/genética , Feminino , Genótipo , Humanos , Masculino , Melanoma/genética , Pessoa de Meia-Idade , Metástase Neoplásica , Inclusão em Parafina , Prognóstico , Estudos Retrospectivos
12.
Clin Cancer Res ; 23(12): 3003-3011, 2017 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-27932416

RESUMO

Purpose: To assess the clinical and pharmacodynamic activity of dovitinib in a treatment-resistant, molecularly enriched non-muscle-invasive urothelial carcinoma of the bladder (NMIUC) population.Experimental Design: A multi-site pilot phase II trial was conducted. Key eligibility criteria included the following: Bacillus Calmette-Guerin (BCG)-unresponsive NMIUC (>2 prior intravesical regimens) with increased phosphorylated FGFR3 (pFGFR3) expression by centrally analyzed immunohistochemistry (IHC+) or FGFR3 mutations (Mut+) assessed in a CLIA-licensed laboratory. Patients received oral dovitinib 500 mg daily (5 days on/2 days off). The primary endpoint was 6-month TURBT-confirmed complete response (CR) rate.Results: Between 11/2013 and 10/2014, 13 patients enrolled (10 IHC+ Mut-, 3 IHC+ Mut+). Accrual ended prematurely due to cessation of dovitinib clinical development. Demographics included the following: median age 70 years; 85% male; carcinoma in situ (CIS; 3 patients), Ta/T1 (8 patients), and Ta/T1 + CIS (2 patients); median prior regimens 3. Toxicity was frequent with all patients experiencing at least one grade 3-4 event. Six-month CR rate was 8% (0% in IHC+ Mut-; 33% in IHC+ Mut+). The primary endpoint was not met. Pharmacodynamically active (94-5,812 nmol/L) dovitinib concentrations in urothelial tissue were observed in all evaluable patients. Reductions in pFGFR3 IHC staining were observed post-dovitinib treatment.Conclusions: Dovitinib consistently achieved biologically active concentrations within the urothelium and demonstrated pharmacodynamic pFGFR3 inhibition. These results support systemic administration as a viable approach to clinical trials in patients with NMIUC. Long-term dovitinib administration was not feasible due to frequent toxicity. Absent clinical activity suggests that patient selection by pFGFR3 IHC alone does not enrich for response to FGFR3 kinase inhibitors in urothelial carcinoma. Clin Cancer Res; 23(12); 3003-11. ©2016 AACR.


Assuntos
Benzimidazóis/administração & dosagem , Carcinoma de Células de Transição/tratamento farmacológico , Quinolonas/administração & dosagem , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/genética , Neoplasias da Bexiga Urinária/tratamento farmacológico , Idoso , Benzimidazóis/efeitos adversos , Carcinoma de Células de Transição/genética , Carcinoma de Células de Transição/patologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Imuno-Histoquímica/métodos , Masculino , Pessoa de Meia-Idade , Mutação , Mycobacterium bovis , Quinolonas/efeitos adversos , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia , Urotélio/patologia
13.
Am J Clin Pathol ; 146(4): 448-55, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27686171

RESUMO

OBJECTIVES: To describe three methods used to screen for frameshift mutations in exon 9 of the CALR gene. METHODS: Genomic DNA from 47 patients was extracted from peripheral blood and bone marrow using the EZ1 DNA Blood Kit (Qiagen, Valencia, CA) and quantified by the Quant-iT PicoGreen dsDNA Assay Kit (Invitrogen, San Diego, CA). After clinical history, cytogenetics, and molecular tests, patients were diagnosed with either clonal or nonclonal hematologic diseases. CALR screening was primarily performed using fragment analysis polymerase chain reaction, then next-generation sequencing and Sanger sequencing. RESULTS: Among the 18 patients diagnosed with clonal diseases, one had acute myeloid leukemia (positive for trisomy 8), and 17 had myeloproliferative neoplasms (MPNs), including chronic myeloid leukemia (CML), essential thrombocythemia (ET), primary myelofibrosis (PMF), and polycythemia vera (PV). Patients with CML were positive for the BCR-ABL1 fusion. Ten patients were positive for JAK2 (PMF, n = 1; ET, n = 2; PV, n = 7), and three were CALR positive (ET, n = 1; PMF, n = 2). Patients diagnosed with a nonclonal disease were negative for JAK2, BCR-ABL, and CALR mutations. CONCLUSIONS: Screening for CALR mutations is essential in BCR-ABL-negative MPNs since it not only provides valuable diagnostic and prognostic information but also identifies potential treatment targets. Since this study describes the importance of screening for known and novel biomarkers, we described in detail three methods that could be easily integrated into a clinical laboratory.


Assuntos
Calreticulina/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mieloide Aguda/diagnóstico , Policitemia Vera/diagnóstico , Mielofibrose Primária/diagnóstico , Trombocitemia Essencial/diagnóstico , Análise Mutacional de DNA , Proteínas de Fusão bcr-abl/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Janus Quinase 2/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mieloide Aguda/genética , Mutação , Policitemia Vera/genética , Mielofibrose Primária/genética , Trombocitemia Essencial/genética
14.
J Mol Diagn ; 18(3): 331-335, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26923179

RESUMO

Accurate identification of somatic mutations in formalin-fixed, paraffin-embedded tumor tissue is required for enrollment into clinical trials for many novel targeted therapeutics, including trials requiring EGFR mutation status in non-small-cell lung carcinomas. Central clinical trial laboratories contracted to perform this analysis typically rely on US Food and Drug Administration-approved targeted assays to identify these mutations. We present two cases in which central laboratories inaccurately reported EGFR mutation status because of improper identification and isolation of tumor material and failure to accurately report assay limitations, resulting in enrollment denial. Such cases highlight the need for increased awareness by clinical trials of the limitation of these US Food and Drug Administration-approved assays and the necessity for a mechanism to reevaluate discordant results by alternative laboratory-developed procedures, including clinical next-generation sequencing.


Assuntos
Análise Mutacional de DNA/normas , Receptores ErbB/genética , Testes Genéticos/normas , Mutação , Idoso , Serviços de Laboratório Clínico/normas , Análise Mutacional de DNA/métodos , Éxons , Feminino , Testes Genéticos/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Laboratórios/normas , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Masculino , Pessoa de Meia-Idade , Medicina de Precisão/métodos , Medicina de Precisão/normas , Reprodutibilidade dos Testes
15.
Ann Surg ; 258(3): 508-15, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24022443

RESUMO

OBJECTIVE: To assess the long-term crossover (CO) rate in men undergoing watchful waiting (WW) as a primary treatment strategy for their asymptomatic or minimally symptomatic inguinal hernias. BACKGROUND: With an average follow-up of 3.2 years, a randomized controlled trial comparing WW with routine repair for male patients with minimally symptomatic inguinal hernias led investigators to conclude that WW was an acceptable option [JAMA. 2006;295(3):285-292]. We now analyze patients in the WW group after an additional 7 years of follow-up. METHODS: At the conclusion of the original study, 254 men who had been assigned to WW consented to longer-term follow-up. These patients were contacted yearly by mail questionnaire. Nonresponders were contacted by phone or e-mail for additional data collection. RESULTS: Eighty-one of the 254 men (31.9%) crossed over to surgical repair before the end of the original study, December 31, 2004, with a median follow-up of 3.2 (range: 2-4.5) years. The patients have now been followed for an additional 7 years with a maximum follow-up of 11.5 years. The estimated cumulative CO rates using Kaplan-Meier analysis was 68%. Men older than 65 years crossed over at a considerably higher rate than younger men (79% vs 62%). The most common reason for CO was pain (54.1%). A total of 3 patients have required an emergency operation, but there has been no mortality. CONCLUSIONS: Men who present to their physicians because of an inguinal hernia even when minimally symptomatic should be counseled that although WW is a reasonable and safe strategy, symptoms will likely progress and an operation will be needed eventually.


Assuntos
Hérnia Inguinal/terapia , Herniorrafia/estatística & dados numéricos , Conduta Expectante , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Assintomáticas , Progressão da Doença , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Resultado do Tratamento , Adulto Jovem
16.
Microvasc Res ; 84(3): 345-50, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22835521

RESUMO

The cutaneous hyperemic response following the release of direct pressure occlusion lasts much longer than the short-term hyperemia that occurs after proximal arterial occlusion. Post-pressure hyperemia may be an important mechanism to prevent pressure induced injury to the skin. The role of vasoactive mediators in modulating post-pressure hyperemia is unknown. In an effort to better understand this phenomenon, we performed an initial study using microdialysis infusion to measure the effect of several known mediators of vascular response on post-pressure hyperemia. A vise clamp was used to apply direct occlusive pressure to a laser Doppler sensor on the skin surface overlying the microdialysis fiber. Skin blood flow was measured continuously pre, during and post-occlusion while infusing the vasoactive substance or control phosphate buffer. Angiotensin II, Calcitonin gene related peptide and histamine had minimal effect on post pressure blood flow. Conversely, prostaglandin E1, prostaglandin E2, and L-NAME diminished the early phase of the post-occlusion hyperemic response. Perhaps the most profound effect we observed was the decrease in post-occlusive blood flow due to administration of epinephrine, dopamine and prostaglandin F2alpha. In contrast, adenosine and caffeine augmented blood flow post occlusion. In this initial survey study, we have demonstrated differential effects of various vascular mediators on the post-pressure hyperemic phenomenon. Our findings may lead to the development of agents to prevent pressure sores by augmenting the skin blood flow response to locally applied pressure.


Assuntos
Hiperemia/tratamento farmacológico , Vasoconstritores/farmacologia , Adenosina/farmacologia , Alprostadil/metabolismo , Animais , Área Sob a Curva , Pressão Arterial , Soluções Tampão , Cafeína/farmacologia , Dinoprostona/metabolismo , Dopamina/farmacologia , Epinefrina/farmacologia , Humanos , Hiperemia/metabolismo , Microdiálise , NG-Nitroarginina Metil Éster/farmacologia , Fosfatos/química , Ratos , Ratos Wistar , Fluxo Sanguíneo Regional/fisiologia , Pele/irrigação sanguínea , Fatores de Tempo
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