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BACKGROUND: This is a multicentre, single-arm, phase II study aimed at further exploring the activity of trabectedin as second-/further-line treatment in retroperitoneal leiomyosarcoma (LMS) and well-differentiated/dedifferentiated liposarcoma (LPS). MATERIALS AND METHODS: The primary endpoint was the growth modulation index (GMI) defined as the ratio between PFS under trabectedin (PFS) and during previous chemotherapy treatment: time to progression (TTP-1). Secondary endpoints were objective response rate (ORR) and PFS. As per protocol, patients were considered responders if the GMI was >1.33, non-responders if <0.75 and neither if 0.76-1.32. RESULTS: Overall 91 patients were assessable for the primary endpoint (32 patients with LMS and 59 patients with LPS): the median number of cycles received was 6.0 (Q1-Q3 3.0-12.0), and the main reason for treatment discontinuation was disease progression in 72% of patients. The median PFS was 6.0 months, while the median TTP1 was 7.5 months (8.1 and 6.4 months for LMS and LPS, respectively). Thirty-three patients [52%, 95% confidence interval (CI) 36% to 58%, P = 0.674, odds of response 1.1] had a GMI >1.33 (LMS 46%, 95% CI 26% to 67%, odds of response 0.85; LPS 56%, 95% CI 40% to 72%, odds of response 1.3). Overall, in LPS we observed 15/47 patients with a GMI <0.5 and 15/47 patients with a GMI >2. Among LMS patients, 9/26 had a GMI <0.5 and 10/26 had a GMI >2. Overall, ORR (complete response + partial response) was 16% (24% for LMS and 12% for LPS). CONCLUSIONS: While the primary endpoint of the study was not met, we noticed a subgroup of patients with a markedly discrepant TTP with trabectedin in comparison to previous therapy (GMI <0.5 or >2, the latter including some patients with a long TTP with trabectedin). A mismatch between PFS and overall survival was observed, possibly due to the natural history of the two different histologies and the availability of further lines in LMS.
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BACKGROUND: Despite its proven activity as third-line treatment in gastrointestinal stromal tumors (GIST), regorafenib can present a poor tolerability profile which often leads to treatment modifications and transient or permanent discontinuation; thus, in clinical practice physicians usually adopt various dosing and interval schedules to counteract regorafenib-related adverse events and avoid treatment interruption. The aim of this real-world study was to investigate the efficacy and safety of personalized schedules of regorafenib in patients with metastatic GIST, in comparison with the standard schedule (160 mg daily, 3-weeks-on, 1-week-off). PATIENTS AND METHODS: Institutional registries across seven Italian reference centers were retrospectively reviewed and data of interest retrieved to identify patients with GIST who had received regorafenib from February 2013 to January 2021. The Kaplan-Meier method was used to estimate survival and the log-rank test to make comparisons. RESULTS: Of a total of 152 patients with GIST, 49 were treated with standard dose, while 103 received personalized schedules. At a median follow-up of 36.5 months, median progression-free survival was 5.6 months [95% confidence interval (CI) 3.73-11.0 months] versus 9.7 months (95% CI 7.9-14.5 months) in the standard-dose and the personalized schedule groups, respectively [hazard ratio (HR) 0.51; 95% CI 0.34-0.75; P = 0.00052]. Median overall survival was 16.6 months (95% CI 14.1-21.8 months) versus 20.5 months (95% CI 15.0-25.4 months), respectively (HR 0.75; 95% CI 0.49-1.22; P = 0.16). CONCLUSIONS: Regorafenib-personalized schedules are commonly adopted in daily clinical practice of high-volume GIST expert centers and correlate with significant improvement of therapeutic outcomes. Therefore, regorafenib treatment optimization in patients with GIST may represent the best strategy to maximize long-term therapy.
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Tumores do Estroma Gastrointestinal , Tumores do Estroma Gastrointestinal/tratamento farmacológico , Humanos , Compostos de Fenilureia/uso terapêutico , Piridinas/uso terapêutico , Estudos RetrospectivosRESUMO
Proper reduction and stable fixation of articular fractures is essential for an early recovery and to avoid late complications. Arthroscopically assisted techniques for minimally invasive fixation have been introduced to reduce local morbidity and improve anatomic reduction of the fragments. However up to date no clear indications for surgery have been given. In addition, the precise rates of functional outcomes and complications are controversial. The hypothesis was the systematic analysis of the available literature would provide precise indications, outcomes and complications of arthroscopically assisted techniques for patellar fracture fixation. A comprehensive literature review was performed using the keywords "patellar fracture", "arthroscopy" with no limit regarding the year of publication. All the selected articles were in English language and were evaluated with the Coleman score by three independent surgeons. The interclass correlation coefficient between the three examiners was calculated. Six full text articles were retrieved. The initial cohort included 60 patients with a displaced transverse fracture in the majority of the cases. At an average FU of 27.2 months the Lysholm score was 91.3. The rate of complication was 7%; Average Coleman score for the three observers was 55.8±6.5 with an ICC of 0.89, indicating adequate inter-rater agreement. Arthroscopically assisted techniques for minimally invasive fixation of patellar fractures represent a reliable option. The positive clinical outcomes and low rates of complications must be confirmed with further studies including larger series and longer FU. LEVEL OF EVIDENCE: Level IV, systematic review of retrospective series.
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Artroscopia/métodos , Fixação Interna de Fraturas/métodos , Fraturas Ósseas/cirurgia , Traumatismos do Joelho/cirurgia , Patela/lesões , Humanos , Patela/cirurgia , Estudos Retrospectivos , Resultado do TratamentoRESUMO
OBJECTIVE: The aim of open anatomic reconstruction of the acromioclavicular (AC) joint is combined reconstruction of the AC and coracoclavicular ligaments using a tendon graft. INDICATIONS: Symptomatic instabilities of the AC joint > type III. CONTRAINDICATIONS: Asymptomatic instabilities < type III and general contraindication against elective surgery. SURGICAL TECHNIQUE: Through the open surgical approach, the exact anatomical insertion sites of the ligamentous structures can be reproduced. In addition, this approach enables accurate repositioning of the AC joint under direct vision (including possible debridement of the intraarticular discus) and an additional fixation of deltotrapezoidal fascia. POSTOPERATIVE MANAGEMENT: Postoperatively, the arm is positioned in an abduction brace for 6-8 weeks. Passive exercises in flexion up to 90° and in external rotation up to 30° are permitted during this period. After 6-8 weeks, free and active motion is allowed. RESULTS: Between January 2003 and December 2010, 46 patients (9 women and 37 men, mean age 42 ± 13 years) underwent AC combined reconstruction. Complete outcome data were available for 25 patients. Mean length of follow-up was 31 ± 26 months. The mean preoperative coracoclavicular distance was 20.1 ± 5.6 mm; postoperatively the mean distance was 7.1 ± 3.0 mm (p < 0.001) The mean clinical scores also statistically improved (p < 0.001): American Shoulder and Elbow Score improved from 53.4 ± 18.7 points preoperatively to 80.6 ± 25.7 points postoperatively and the Constant Murley Score improved from 60.0 ± 16.7 points preoperatively to 85.2 ± 22.8 points postoperatively.
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Articulação Acromioclavicular/cirurgia , Artroplastia/métodos , Artroplastia/reabilitação , Terapia por Exercício/métodos , Imobilização/métodos , Instabilidade Articular/cirurgia , Adulto , Feminino , Humanos , Instabilidade Articular/diagnóstico , Instabilidade Articular/reabilitação , Masculino , Resultado do TratamentoRESUMO
Chemoresistance is an important concern in the treatment of metastatic colon cancer. It may emerge through selection of clones that are inherently resistant from the outset or through mechanisms acquired during treatment. Cell fusion represents an efficient means of rapid phenotypic evolution that make cells with new properties at a rate exceeding that achievable by random mutagenesis. Here, we first identified a number of proteins involved in cell fusion using a shotgun proteomics approach, then we investigated the role of these proteins namely tetraspanin CD81/CD9, ADAM10, GTP-binding protein α13, radixin, myosin regulatory light chain and RhoA in the regulation of colon cancer cell fusion. We also found a previously unrecognized role of ADAM10, Gα13 and RhoA in promoting cell fusion. Finally, we show that the occurrence of cell fusion in a metastatic model of colon carcinoma causes the appearance of cells resistant to both 5-fluorouracil and oxaliplatin. These findings highlight the importance of cell fusion in cancer progression and raise significant implications for overcoming chemoresistance in metastatic colon cancer.
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Neoplasias do Colo/metabolismo , Resistencia a Medicamentos Antineoplásicos , Modelos Biológicos , Proteínas de Neoplasias/metabolismo , Animais , Antimetabólitos Antineoplásicos/farmacologia , Bovinos , Fusão Celular , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Fluoruracila/farmacologia , Humanos , Camundongos , Metástase Neoplásica , Proteínas de Neoplasias/genética , Compostos Organoplatínicos/farmacologia , Oxaliplatina , ProteômicaRESUMO
The combination of pegylated interferon (Peg-IFN) and ribavirin is currently the gold standard therapy in patients with HCV chronic infection. The duration of therapy, as well as the therapeutic dosage, depend on the genotype. Identification of the genotype and rapid virological response (RVR) are widely accepted as the most important predictors of clinical outcome during antiviral therapy but to optimize cost-benefits and to reduce possible side effects, further prognostic factors are needed. Squamous cell carcinoma antigens immunocomplex (SCCA-IC) has been reported to be increased in the serum of patients with liver cancer. In this multicentric prospective study, we investigated the serum levels of SCCA-IC in 103 patients with HCV chronic infection. Serum HCV-RNA was detected before the beginning of treatment, after 4, 12, 24 or 48 weeks, and at week 24 during follow-up. RVR, early virological response and sustained virological response (SVR) were assessed following the international guidelines. SCCA-IC levels were higher in responders (238 AU, interquartile difference 130-556 AU) and decreased significantly to 125 AU (70-290 AU). The mean baseline value in nonresponders was 149 AU (86.5-306.5 AU), but after 4 weeks of treatment the serum levels decreased to 115 AU (80-280 AU): the profile of reduction was different between patients with or without a positive SVR. Logistic regression with SVR as dependent variable identified as significant independent variables: the reduction in SCCA-IC after 1 month (OR = 4.82; 95% CI 1.39-16.67; P = 0.131) and a genotype other than 1 (OR = 0.094; 95% CI 0.21-0.42; P = 0.002); sex and age were also significant factors influencing SVR. SCCA-IC seems to be a reliable independent prognostic marker of therapeutic effectiveness in anti-HCV positive patients undergoing antiviral therapy.
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Complexo Antígeno-Anticorpo/sangue , Antígenos de Neoplasias/sangue , Antivirais/administração & dosagem , Biomarcadores/sangue , Hepatite C Crônica/tratamento farmacológico , Serpinas/sangue , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , RNA Viral/sangue , Resultado do Tratamento , Carga ViralRESUMO
BACKGROUND: Most functions of tetraspanins are not related to cell-surface receptor ligand binding, but are mediated by direct interactions with their partner proteins. Functions of trimeric FcÉRI, expressed by antigen-presenting cells (APCs), range from amplification of allergic inflammatory reactions to their active suppression. Cell-type-specific protein-protein interactions might play a role in the regulation of these bidirectional tasks. Therefore, we intended to study the interactions of trimeric FcÉRI with tetraspanins. METHODS: The expression levels of tetraspanins CD9, CD37, CD53, CD63, CD81, CD82, and CD151 on skin dendritic cells of atopic dermatitis (AD) patients or healthy individuals were detected by flow cytometry. Tetraspanin expression on FcÉRI(pos) and FcÉRI(neg) monocyte subpopulations was evaluated. Flow cytometry, confocal microscopy, immunoprecipitation, and immunoblotting experiments were performed to observe the relationship between tetraspanins CD9 and CD81 and FcÉRI. Furthermore, plate stimulation experiments were performed, and cytokines in the supernatants were detected. RESULTS: We found that human FcÉRI(pos) APCs expressed high amounts of tetraspanins and that the tetraspanins CD9 and CD81 were associated with FcÉRI. Concomitant activation of FcÉRI and CD9 on human monocytes increased FcÉRI-mediated cytokine release. CONCLUSION: Taken together, we show for the first time that CD9 and CD81 act as molecular partners of trimeric FcÉRI on human APC, which might be of importance in allergic diseases such as AD.
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Células Apresentadoras de Antígenos/química , Antígenos CD/metabolismo , Células Dendríticas/química , Dermatite Atópica/imunologia , Glicoproteínas de Membrana/metabolismo , Receptores de IgE/metabolismo , Células Apresentadoras de Antígenos/imunologia , Antígenos CD/análise , Estudos de Casos e Controles , Humanos , Glicoproteínas de Membrana/análise , Ligação Proteica , Receptores de IgE/análise , Pele/patologia , Tetraspanina 28 , Tetraspanina 29RESUMO
The objective of this study was to evaluate the expression of MMP-2 and MMP-9 in sentinel lymph node and serum of breast cancer patients in order to evaluate their clinical significance and usefulness as diagnostic tumour markers. Expression of MMP-2 and MMP-9 was performed on sentinel lymph node by immunohistochemistry while gelatine zymography was used to determinate the serum expression. The association of gelatinases with clinicopathological features, were analysed. Metastatic and non-metastatic breast cancer patients and 34 healthy women were involved. Gelatinases expression were significantly higher in metastatic breast cancer in comparison to non-metastatic cancer and the control group both in the sentinel lymph node and serum. Results showed a statistically significant correlation between MMP-2 or MMP-9 and cancer familiality, MMP-9 and CA 15.3 levels, and MMP-9 and grading. This study suggests a clinical utility of these proteolytic markers in malignant tumour, growth, invasion and metastasis in breast cancer.
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Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Metaloproteinase 2 da Matriz/biossíntese , Metaloproteinase 9 da Matriz/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Neoplasias da Mama/sangue , Feminino , Humanos , Imuno-Histoquímica , Linfonodos/enzimologia , Metástase Linfática/patologia , Metaloproteinase 2 da Matriz/sangue , Metaloproteinase 9 da Matriz/sangue , Pessoa de Meia-Idade , Invasividade Neoplásica/patologia , Prognóstico , Biópsia de Linfonodo Sentinela , Adulto JovemRESUMO
BACKGROUND AND AIMS: Myofibroblast-like cells, originating from activation of hepatic stellate cells (HSC/MFs), play a key role in liver fibrosis, a potentially reversible process that may rely on induction of HSC/MFs apoptosis. While this possibility has been shown in cultured rat HSC, very limited data are currently available for human HSC/MFs. METHODS: Cultured human HSC/MFs were exposed to several proapoptotic stimuli, including those known to induce apoptosis in rat HSC/MFs, and induction of cell death and related mechanisms were investigated using morphology, molecular biology, and biochemical techniques. RESULTS: In this study we report that fully activated human HSC/MFs did not undergo spontaneous apoptosis and survived to prolonged serum deprivation, Fas activation, or exposure to nerve growth factor, tumour necrosis factor alpha (TNF-alpha), oxidative stress mediators, doxorubicin, and etoposide. Induction of caspase dependent, mitochondria driven apoptosis in HSC/MFs was observed only when protein synthesis or transcription were inhibited. Importantly, the process of HSC activation was accompanied by changes in expression of a set of genes involved in apoptosis control. In particular, activated human HSC/MFs in culture overexpressed Bcl-2. The role of Bcl-2 was crucial as Bcl-2 silenced cells became susceptible to TNF-alpha induced apoptosis. Finally, Bcl-2 was markedly expressed in HSC/MFs present in liver tissue obtained from patients with hepatitis C virus related cirrhosis. CONCLUSIONS: Human activated HSC/MFs are resistant to most proapoptotic stimuli due to Bcl-2 overexpression and this feature may play a key role in the progression of fibrosis in chronic liver diseases.
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Apoptose , Cirrose Hepática/patologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/farmacologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Progressão da Doença , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Cirrose Hepática/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/fisiologia , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
Expression of the integrin, alpha6beta1, a receptor for laminins, is associated with the progression of hepatocellular carcinoma (HCC). The approach to investigating the alpha6beta1 integrin signaling in HCC cells was to express a deletion mutant of the beta4 integrin cytoplasmic domain (beta4-Deltacyt) in 2 HCC cell lines, HepG2 and Huh7. Expression of this mutant prevents formation of the alpha6beta1 heterodimer. As expected, adhesion of both the HepG2/beta4-Deltacyt and Huh7/beta4-Deltacyt transfectants to laminin, but not to collagen, was reduced compared with the mock transfectants. However, migration of the beta4-Deltacyt transfectants toward both collagen and laminin was inhibited, suggesting a role for alpha6beta1 in the signaling of migration. Migration of HCC cells requires mitogen-activated protein (MAP) kinase. The adhesion of the beta4-Deltacyt transfectants to collagen resulted in a substantial reduction in MAP kinase activation in comparison with the mock transfectants, although their ability to activate MAP kinase in response to epidermal growth factor (EGF) stimulation was not impaired. In addition, matrix adhesion of the beta4-Deltacyt transfectants did not stimulate the tyrosine phosphorylation of focal adhesion kinase (FAK), and this defect correlated with reduced binding of adaptor protein Grb2 to FAK. These results suggest that FAK tyrosine phosphorylation is dependent on alpha6beta1 expression, and that FAK-Grb2 association plays a central role in alpha6beta1-mediated activation of MAP kinase. Moreover, the expression of alpha6beta1 in HCC cells is necessary for FAK/MAP kinase-dependent migration.
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Carcinoma Hepatocelular/patologia , Matriz Extracelular/fisiologia , Integrinas/fisiologia , Neoplasias Hepáticas/patologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteínas Tirosina Quinases/metabolismo , Adesão Celular , Movimento Celular , Colágeno , Meios de Cultura , Ativação Enzimática , Quinase 1 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Humanos , Integrina alfa6beta1 , Cinética , Laminina , Fosforilação , Fosfotirosina/metabolismo , Células Tumorais CultivadasRESUMO
The purpose of this study was to compare retrospectively the results of a single-stage dorsal approach versus the posterior approach for the surgical treatment of congenital vertical talus (CVT) at a single institution. Twenty-four patients (33 feet) with CVT were treated surgically between 1960 and 1998. Eighteen patients (25 feet) underwent a posterior release (group 1), and six patients (eight feet) underwent surgery via the dorsal approach (group 2). All patients were evaluated at a minimal follow-up of 3 years. Preoperative and follow-up radiographs were evaluated, and a modified version of the clinical score by Adalaar was used. Group 1 had 45 procedures on 25 feet, whereas group 2 had no repeated or revision operations. The clinical score was 6.75 for group 1 and 8.0 for group 2. Tourniquet time was 123 minutes and 87 minutes for groups 1 and 2, respectively. Twelve group 1 patients (48%) had avascular necrosis (AVN) versus none of the group 2 patients. Both groups had similar preoperative and postoperative radiographic measurements. Both approaches were able to reduce successfully the talonavicular joint; however, the single-stage dorsal incision group required significantly less operative time, had better clinical scores, and had fewer complications 3 years after surgery.
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Deformidades Congênitas do Pé/cirurgia , Procedimentos Ortopédicos/métodos , Tálus/anormalidades , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-OperatóriasRESUMO
Pathogenic mechanisms of B-cell lymphoproliferative disorders in chronic hepatitis C virus (HCV) infection are unclear. We studied t(14;18) translocation by polymerase chain reaction in peripheral blood mononuclear cells from 50 patients with HCV-related liver disease (group A), 7 with mixed cryoglobulinemia syndrome (group B), 55 with HCV-negative liver disease (group C), and 30 with HCV-negative chronic rheumatic disorders or chronic infection by nonhepatotropic agents (group D). T(14;18) was significantly more frequent in group A (13/50 patients = 26 %) and group B (5/7 = 71.4%) patients than in group C (1/55 = 3.6%) and group D (1/30 = 3.3%) ones. Immunoblot analysis showed bcl-2 over-expression in all t(14;18)-positive samples. In group A, 10/13 (77%) patients with t(14;18) and 13/37 (35%) without t(14;18) had serum cryoglobulins in the absence of mixed cryoglobulinemia symptoms (P <.05). These data indicate that t(14;18) and bcl-2 over-expression in lymphoid cells are frequent in chronic HCV infection and suggest that this event may contribute to the pathogenesis of HCV-related lymphoproliferative disorders.
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Cromossomos Humanos Par 14/genética , Cromossomos Humanos Par 18/genética , Hepatite C Crônica/genética , Translocação Genética/genética , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Crioglobulinemia/sangue , Crioglobulinemia/genética , Crioglobulinas/análise , Feminino , Frequência do Gene , Hepatite C Crônica/sangue , Hepatite C Crônica/complicações , Humanos , Infecções/sangue , Infecções/genética , Hepatopatias/sangue , Hepatopatias/genética , Hepatopatias/virologia , Masculino , Pessoa de Meia-Idade , Monócitos/fisiologia , Proteínas Proto-Oncogênicas c-bcl-2/sangue , Doenças Reumáticas/sangue , Doenças Reumáticas/genéticaAssuntos
Fator de Crescimento Insulin-Like I/fisiologia , Hepatopatias/complicações , Osteocalcina/fisiologia , Osteoporose/etiologia , Osteoporose/fisiopatologia , Idoso , Hepatite B/complicações , Hepatite C/complicações , Humanos , Fator de Crescimento Insulin-Like I/análise , Cirrose Hepática/complicações , Pessoa de Meia-Idade , Osteocalcina/sangue , Osteoporose/sangueRESUMO
The proximal radioulnar joint was dissected in 24 cadaveric elbows to localize the area of the radial head that did not articulate with the lesser sigmoid notch of the ulna. The nonarticulating portion of the radial head was posterolateral in the anatomic position of full supination. Gross observations of the nonarticulating portion of the radial head revealed a thinner band of yellowish cartilage relative to a wider, white, glistening cartilage of the articular portion of the radial head. The nonarticular portion of the radial head did not contain the angled peak, which is most prominent in the middle of the articular portion. The average arc of the nonarticulating radial head was 113 degrees (range, 106 degrees to 120 degrees; standard deviation, 4 degrees). This nonarticulating portion of the radial head (or safe zone for prominent fixation) consistently encompassed a 90 degrees angle localized by palpation of the radial styloid and Lister's tubercle. Using these palpable distal landmarks to localize the safe zone of the radial head, 24 different cadaveric elbows were internally fixed with a plate and screws through 3 different approaches (anterior, lateral, and posterolateral). Regardless of approach, the internal fixation allowed full forearm rotation in all the specimens. Utilization of this method and anatomic landmarks to localize the nonarticular portion of the radial head may assist the surgeon in open reduction and internal fixation of fractures of the radial head and neck.
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Articulação do Cotovelo/anatomia & histologia , Fixação Interna de Fraturas/métodos , Fraturas do Rádio/cirurgia , Rádio (Anatomia)/anatomia & histologia , Cadáver , Cartilagem Articular/anatomia & histologia , Articulação do Cotovelo/fisiologia , Humanos , Pronação , Rotação , SupinaçãoRESUMO
In intact bovine heart mitochondria, cAMP-dependent phosphorylation of 42, 29, 18 and 6.5 kDa proteins was inhibited by carboxyatractyloside. This shows that both mitochondrial cAMP-dependent protein kinase (mtPKA) and its protein substrates are localized at the matrix side of the inner mitochondrial membrane. Proteins of 42, 29, 18, and 6.5 kDa were also bound at the outer surface of mitochondria where they were phosphorylated by the added purified catalytic subunit of PKA. In the cytosol from bovine heart proteins of the above molecular weights were phosphorylated by the cytosolic PKA.
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Proteínas Quinases Dependentes de AMP Cíclico/análise , Membranas Intracelulares/enzimologia , Proteínas de Membrana/metabolismo , Mitocôndrias Cardíacas/enzimologia , Animais , Atractilosídeo/análogos & derivados , Atractilosídeo/farmacologia , Bovinos , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Citosol/metabolismo , Proteínas de Membrana/análise , FosforilaçãoRESUMO
Good exercise prescriptions provide work rates (WRs) that maintain heart rates (HR) in a target zone and at a percent of maximum metabolic equivalent (%METmax). HR and MET were evaluated from computer-controlled and set WR (constant speed) sessions (20 min at 65% METmax). Computer-controlled WR used a control algorithm to adjust speed and grade to maintain the target HR. The set WR (mean +/- S.D.) HR (139 +/- 8 bpm) was lower (p less than 0.05) than the target (147 +/- 3 bpm) and computer-controlled HRs (153 +/- 5 bpm). The set WR MET (8.6 +/- 2.2) was not different than the target (8.6 +/- 2.2), but both were lower than computer-controlled exercise (9.7 +/- 2.2). Computer-control time in target HR zone (16 +/- 5 min) was significantly (p less than 0.004) greater than set WR exercise (6 +/- 5 min). Computer-controlled WR was significantly better in maintaining target HR and the MET values were not physiologically different than target WRs.