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1.
J Sports Med Phys Fitness ; 59(4): 648-654, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29877678

RESUMO

BACKGROUND: The aim of this investigation was to provide a detailed analysis of accidents on ski slopes of Styrian resorts comparing two winter seasons. METHODS: Accident data requiring the presence of the ski patrol of the seasons 2007/08 (10 skiing resorts with 1029 injuries) and 2014/15 (8 resorts with 1844 injuries) were recorded. Accidents were normalized to 1000 skier days and 10000 lift transports. Patients were followed to hospitals to obtain information about injured body region, final diagnosis and type of treatment. RESULTS: A slight increase of injuries from 0.5 to 0.7 per 1000 skier-days was found (P=0.046). Overall, the knee was most commonly affected followed by shoulder, lower leg, head and forearm. While the shoulder was most often affected in men the knee was most commonly affected in women. Patients <15 years had a higher prevalence of forearm injuries. Comparing the two seasons the use of helmets and spine protectors increased, associated with decreased injuries of these body regions. The hospitalization rate was 26% in both seasons; patients <15 years required less inpatient treatment than older ones. CONCLUSIONS: Different injury patterns between gender and age-groups have to be taken into account for future preventive measures. The increased acceptance of safety equipment was associated with reduced injury rates of the respective body regions. Results of the present study can facilitate to develop future injury prevention strategies in order to further decrease the number of casualties on ski slopes.


Assuntos
Acidentes/estatística & dados numéricos , Traumatismos em Atletas/epidemiologia , Esqui/lesões , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Equipamentos de Proteção , Estações do Ano
2.
Am J Surg ; 213(6): 1038-1041, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27765183

RESUMO

BACKGROUND: In an experimental study the performance of different closed abdominal drainage systems was tested. METHODS: A vacuum bottle designed for Redon Drainage, a flexible plastic bulb designed for Jackson-Pratt drains and a V.A.C.® Negative Pressure Wound Therapy System were used. In a porcine cadaveric study mimicking the abdominal cavity the intrinsic pressure (IP) at one and three minutes (T0, T3) and the amount of evacuated fluid were measured. RESULTS: The Redon and Jackson drainage displayed a rapid decline to IP values of almost zero comparing T0 and T3. Only the V.A.C.® system was able to preserve constant values of negative IP values measured at both time points. Only the V.A.C.® system was able to remove almost the whole amount of inserted fluid. CONCLUSIONS: In an experimental setting the V.A.C.® system was superior to the other two tested systems in delivering constant negative IP and the amount of evacuated fluid.


Assuntos
Cavidade Abdominal/cirurgia , Drenagem/instrumentação , Tratamento de Ferimentos com Pressão Negativa/instrumentação , Animais , Desenho de Equipamento , Complicações Pós-Operatórias , Suínos
3.
Foot Ankle Int ; 36(1): 60-3, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25237176

RESUMO

BACKGROUND: Foot fractures account for 5% to 13% of pediatric fractures. Fractures of the hallux require special attention due to its role in weight bearing, balance, and pedal motion. In this study, a large series of children with hallux fractures is presented. METHODS: All children treated with fractures of the hallux between June 2004 and December 2011 were included. The medical records were analyzed and X-rays were reviewed. The fractures were classified according to their anatomic location and the type of fracture. Three hundred seventeen patients (mean age = 11.7 years; range, 1-18 years; 65% male) sustained a fracture of the hallux. RESULTS: Most accidents (28%) occurred at sports facilities, and soccer was the most common cause of a fracture of the hallux (28%). Closed injuries were diagnosed in 92% of the patients; 8% of the children presented with open fractures. In 144 children, the growth plate was affected. Fifty-nine patients presented with diaphyseal fractures, 42 patients with osseous avulsions, and 40 patients with fractures of the distal part of the phalanx. Nineteen children had incomplete and 13 patients comminuted fractures. The vast majority of the children (86%) were treated conservatively. Operative interventions were required in 14% of the patients. Good outcome was achieved in both conservatively and operatively treated patients. CONCLUSION: In children, fractures of the hallux were most often caused by ball sports and had a good prognosis. The vast majority of these fractures could be treated conservatively yielding good outcome. LEVEL OF EVIDENCE: Level IV, case series.


Assuntos
Fraturas Ósseas/terapia , Fraturas Cominutivas/cirurgia , Hallux , Adolescente , Traumatismos em Atletas/epidemiologia , Traumatismos em Atletas/terapia , Criança , Pré-Escolar , Feminino , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/cirurgia , Hallux/diagnóstico por imagem , Hallux/cirurgia , Humanos , Lactente , Masculino , Traumatismo Múltiplo/epidemiologia , Radiografia , Futebol/lesões
4.
Wound Repair Regen ; 22(5): 654-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25139317

RESUMO

Silver-containing wound dressings are an integral part of wound therapy in adult and pediatric burn patients. The antimicrobial effect of silver is well known and has been described in numerous studies. Side effects are rarely reported from silver-containing wound care products, even though systemic absorption of silver has been shown by elevated levels of silver in the blood of patients after silver exposure during wound therapy. This animal study investigated the silver levels of blood and in which organs and tissues silver is detectable after long-term application of silver-containing wound dressings after a burn trauma. In male rats, a major full-thickness scald was created on their backs according to a standardized burn model. Two different silver-containing wound dressings (nanocrystalline silver [NCS] and silver sulphate foam [SSF]) were applied initially and changed every 7 days. Weekly blood drawings revealed an increase of blood silver in week three with significant higher values in the SSF compared with NCS group (Ag µg/kg 135.8 vs. 61.7; means; p ≤ 0.05). Thereafter, the NCS group showed significantly higher blood silver levels than the SSF group at week five (Ag µg/kg 192.3 vs. 81.3; means; p ≤ 0.01) and six (Ag µg/kg 168.2 vs. 32.9; means; p ≤ 0.01). After 6 weeks, the animals were sacrificed, and the organs and tissues were analyzed for their silver content by inductively coupled plasma mass-spectrometry. Silver was detectable in all analyzed organs and tissue samples, with higher silver values in parenchymatous organs in the NCS than SSF group (Ag µg/kg; spleen: 3,469 vs. 260; kidney: 3,186 vs. 289; liver: 2,022 vs. 313; means; p ≤ 0.05). Silver was also detectable in brain, testis, lung, heart, and muscle tissue.


Assuntos
Bandagens , Queimaduras/terapia , Rim/metabolismo , Fígado/metabolismo , Compostos de Prata/metabolismo , Absorção Cutânea , Baço/metabolismo , Animais , Rim/química , Fígado/química , Masculino , Espectrometria de Massas , Nanopartículas Metálicas , Ratos , Compostos de Prata/sangue , Baço/química
5.
J Pediatr Surg ; 49(3): 474-6, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24650481

RESUMO

BACKGROUND/PURPOSE: Ulnar polydactylies present with a wide variation in the size and appearance of the affected finger, ranging from small cutaneous appendages to fully formed additional fingers. Since ulnar polydactyly is rarely associated with functional disabilities, psychological and cosmetic reasons are the main rationale for surgical treatment. The aim of this study was to present the appearance, treatment regimen, and outcome of a series of children treated with ulnar polydactylies. METHODS: Data of all pediatric patients treated between 2000 and 2010 were included. For assessing long-term outcome, patients were contacted via mail and asked to complete a questionnaire concerning location and appearance of the scar as well as functional and cosmetic satisfaction (VAS 0-100). RESULTS: In that period, 32 patients (20 male, 12 female) with 53 ulnar polydactylies were treated. In 20 patients the polydactyly occurred bilaterally (63%), in 10 patients on the left side (31%), and 2 patients presented with right-sided ulnar polydactyly (6%). The vast majority of ulnar polydactylies were floating cutaneous appendages. The mean age of the patients at operation was 8.6 months (range 0 to 10 years). 20 patients (63%) responded to the postal questionnaire. Follow-up time was 4.9 years (range 2.1 to 10 years). The majority of patients reported a flat scar (n=18, 90%). Mean overall satisfaction with the postoperative result using a VAS 0-100 score was 89. CONCLUSION: We were able to report a good postoperative outcome of a series of patients suffering from ulnar polydactylies.


Assuntos
Amputação Cirúrgica/métodos , Dedos/anormalidades , Polidactilia/cirurgia , Criança , Pré-Escolar , Cicatriz/epidemiologia , Cicatriz/psicologia , Denervação/métodos , Estética , Feminino , Dedos/inervação , Dedos/cirurgia , Seguimentos , Deformidades Adquiridas da Mão/epidemiologia , Deformidades Adquiridas da Mão/psicologia , Humanos , Lactente , Recém-Nascido , Masculino , Neuroma/prevenção & controle , Satisfação do Paciente , Polidactilia/psicologia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/psicologia , Estudos Retrospectivos , Inquéritos e Questionários , Resultado do Tratamento
6.
BMC Pediatr ; 14: 55, 2014 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-24571577

RESUMO

BACKGROUND: Failure to thrive and hematochezia in children may be alarm signs warranting endoscopy. In contrast, vascular malformations of the small intestine are uncommon in this age group. We report on a female toddler in whom various imaging techniques revealed an unusually large segmental vascular malformation of the ileum as the cause of the child's main clinical symptoms. CASE PRESENTATION: A 19 months old girl presented with severe anemia (Hb 3 mmol/l), failure to thrive and chronic diarrhea. Diagnostics for intestinal blood loss and pathogens were negative. The child had duodenoscopy, also for histological diagnosis of celiac disease, with negative results. A dietary protocol was suggestive for inadequate iron intake and she was supplemented. After symptomless four-months the child presented again, now with mild abdominal pain and, for the first time, hematochezia. An orienting abdominal ultrasound (US) study showed a suspicious tumorous bowel condition. A subsequent detailed abdominal US supplemented by a saline enema during investigation (i.e., "hydrocolon", to improve outlining of the formation's localization) revealed a large circumferential cystiform vascular mass of the ileum causing segmental ileal obstruction.Complementing preoperative abdominal hydro-MRI, planned based on the findings of the US study, confirmed the suspected vascular malformation of the ileum and exquisitely outlined the extent, location and anatomy.The patient was successfully operated laparoscopically, the affected ileum segment with the mass was completely removed as proven by histology, and the child recovered well. CONCLUSIONS: The huge segmental vascular malformation of the distal ileum described here is an extreme rarity in young children. Although the reported child's presenting symptoms malabsorption and malnutrition could have been responsible for its severe anemia, this was obviously caused by blood losses from the ileal vascular malformation. It was due to incipient abdominal pain rather than hematochezia that abdominal US was performed and proved crucial for correctly diagnosing this rare malformation. Even in this extensive case detailed imaging work-up including adapted MRI added all information necessary for minimal invasive laparoscopic en bloc resection.


Assuntos
Íleo/irrigação sanguínea , Malformações Vasculares/diagnóstico , Feminino , Hemorragia Gastrointestinal/etiologia , Humanos , Lactente , Malformações Vasculares/complicações
7.
J Minim Invasive Gynecol ; 20(5): 714-6, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23680516

RESUMO

Intrauterine ovarian torsion is a rare event, but it is a possible cause for unilateral ovarian aplasia. Most commonly the ovary undergoes autolysis after torsion so that no tissue or remnants can be discovered on the involved side. We report a rare case of unilateral intrauterine torsion followed by autoamputation and abdominal reimplantation resulting in an intra-abdominal complex cystic mass with a review of the literature.


Assuntos
Abdome/cirurgia , Cistos Ovarianos/cirurgia , Anormalidade Torcional/cirurgia , Abdome/diagnóstico por imagem , Feminino , Humanos , Lactente , Cistos Ovarianos/diagnóstico por imagem , Anormalidade Torcional/diagnóstico por imagem , Resultado do Tratamento , Ultrassonografia
9.
J Trauma ; 71(2): E19-25, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21045737

RESUMO

BACKGROUND: Injury represents a major concern for children and adolescents worldwide. It is estimated that 10% to 25% of all pediatric injuries will result in fractures. This study aimed to analyze the epidemiology, gender distribution, age, and circumstances of fractures in childhood in a Level I Trauma Center in Austria. METHODS: Children managed with fractures between December 2004 and October 2006 were prospectively evaluated. Patients were divided into four age groups: infants (<1 year), preschool children (1-6 years), school-aged children (6-14 years), and adolescents (>14 years). RESULTS: The study included 3,339 patients younger than 19 years, who presented with 3,421 fractures. There was a male predominance (61.3%, n = 2,096). Girls (38.7%, n = 1,325) had a lower mean age at presentation of 8.2 years (boys, 9.8 years). An increase in the incidences of fractures was observed until a peak of 11 years in girls and 12 years in boys. A majority of fractures occurred in sports facilities (34.7%), followed by those at home (17.6%) and outdoors (16.7%). The most frequent mechanisms were falls on level surface (41.9%), falls from a height <3 m (23.2%), and involuntary contact with persons or objects (18.2%). The most common fractures were those of the distal radius (15.3%), followed by those of the finger (14%) and distal forearm fractures (8%). CONCLUSION: As the Department of Pediatric Surgery in Graz serves as the referral center at least for nearly all major pediatric fractures in the Austrian state of Styria, mechanisms and patterns of major fractures in this study can serve as the basis for state-wide pediatric injury prevention efforts. These prevention strategies should not aim to reduce the level of exposure but should increase the risk awareness and encourage children and their parents to use necessary precautions.


Assuntos
Fraturas Ósseas/epidemiologia , Acidentes Domésticos/estatística & dados numéricos , Acidentes de Trânsito/estatística & dados numéricos , Adolescente , Traumatismos em Atletas/epidemiologia , Áustria/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Traumatismo Múltiplo/epidemiologia , Fraturas do Rádio/epidemiologia , Centros de Traumatologia
10.
Acta Paediatr ; 99(9): 1370-3, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20219026

RESUMO

INTRODUCTION: The aim of this study was to evaluate our experience with single-port appendectomy (SPA) in obese children. METHODS: From January 2003 to June 2009, 94 SPA (65 women and 29 men, mean age of 12.4 years) were performed in children with appendicitis. Sixty-five of these patients were found to have normal weight, whereas 29 were obese. Patients' records were evaluated regarding operative time, intra- and post-operative complications, initiation of oral intake and histopathological findings. RESULTS: There was no significant difference in operative time between obese and normal weight patients. In the obese group, one wound healing disturbance was documented. In the normal weight group, there were one post-operative bleeding and one wound infection. There was no difference with regards to the introduction of feeds following appendectomy between the groups. Histological examinations revealed 15 normal, 32 acute, 21 phlegmonous, 20 chronic and two perforated cases of appendicitis, three neurogenic appendicopathies and one case of enterobius vermicularis related appendicitis. CONCLUSIONS: Our results indicate that the advantages of single-port appendectomy in the evaluation of the peritoneal cavity, the minimal rate of intra-operative incidents with this technique and superior cosmetics validate this alternative approach of minimal access appendectomy in obese children.


Assuntos
Apendicectomia/métodos , Apendicite/cirurgia , Laparoscopia/métodos , Obesidade , Adolescente , Criança , Contraindicações , Feminino , Humanos , Complicações Intraoperatórias/prevenção & controle , Masculino , Complicações Pós-Operatórias/prevenção & controle , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
11.
Eur J Pediatr ; 168(2): 163-6, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18461361

RESUMO

While it has been shown that non-parental child care is associated with a reduced risk for unintentional injuries, a considerable number of accidents in kindergartens do result in severe injuries. We have collected data on the behavioral and environmental aspects of accidents that occurred in kindergartens in Austria with the aim of determining possible prevention measures. Included in the study were all kindergarten-related injuries (347) from among 21,582 pediatric trauma cases treated in a 22-month period in Graz, Austria. Kindergarten-related injuries that were treated during the same period at six participating hospitals located throughout Austria were used for comparison. A questionnaire was completed at first attendance, and additional information was achieved by interviews with the parents and kindergarten teachers. Only the 347 kindergarten accidents that occurred in Graz were analyzed in detail. Half of the injuries occurred in an outdoor environment (outside), even though most of the time was spent indoors. Boys were more frequently involved in accidents than girls (male:female=3:2). We identified seasonal and circadian differences, with most children being injured during the first 2 months of attendance (September and October), during the first 3 days of the week (Monday to Wednesday) and in the hour before and after lunch, respectively. Of the 347 accidents analyzed, 24% resulted in serious injury, and injuries occurring outdoors were more severe than those occurring indoors. Most parents felt that the accidents were unpreventable (47%), while 18% stated that improved supervision may have prevented the accident. Kindergarten accidents in Austria still result in a significant number of severe injuries. Kindergarten injuries were related to gender, season, time of day and location. Our results indicate the necessity of a continuous child safety training program that involves the participation of all teachers in day-care functions.


Assuntos
Acidentes/estatística & dados numéricos , Creches/estatística & dados numéricos , Ferimentos e Lesões/epidemiologia , Áustria , Causalidade , Pré-Escolar , Ritmo Circadiano , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Jogos e Brinquedos , Estudos Prospectivos , Fatores de Risco , Estações do Ano , Fatores Sexuais , Ferimentos e Lesões/prevenção & controle
12.
Clin Orthop Relat Res ; 466(7): 1705-9, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18443894

RESUMO

UNLABELLED: A Galeazzi fracture is defined as a fracture of the radius associated with dislocation of the distal radioulnar joint. Treatment in children and adolescents is usually possible with closed reduction and casting. The objective of this retrospectively designed study was to describe all Galeazzi lesions treated at our department during a 3-year period. One hundred ninety-eight patients with displaced fractures of the radius alone or both bones of the forearm were reviewed. In 26 (13%) cases, a Galeazzi lesion was found and these patients formed the study group. Outcome was assessed using the Gartland-Werley score. Eight of 26 (31%) fractures were recognized initially and classified as a Galeazzi lesion. Casting after fracture reduction was possible in 22 patients. Thirteen patients were treated with immobilization in a below-elbow cast and nine with an above-elbow cast. Four patients were treated operatively. The results were excellent in 23 cases and good in three cases. In cases of distal forearm fractures, a possible Galeazzi lesion should be considered. However, proper reduction of the radius with concomitant reduction of the distal radioulnar joint and cast immobilization provides good to excellent outcome even if the Galeazzi lesion is primarily not recognized. LEVEL OF EVIDENCE: Level IV, therapeutic study.


Assuntos
Traumatismos do Antebraço/terapia , Luxações Articulares/terapia , Fraturas do Rádio/terapia , Adolescente , Áustria , Moldes Cirúrgicos , Criança , Erros de Diagnóstico/estatística & dados numéricos , Feminino , Traumatismos do Antebraço/epidemiologia , Humanos , Incidência , Luxações Articulares/complicações , Luxações Articulares/epidemiologia , Masculino , Rádio (Anatomia) , Fraturas do Rádio/complicações , Fraturas do Rádio/epidemiologia , Estudos Retrospectivos , Resultado do Tratamento , Ulna
14.
J Pediatr Surg ; 42(9): 1584-7, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17848253

RESUMO

BACKGROUND: This study aimed to evaluate the incidence and severity of pin tract infections in a series of pediatric trauma patients. METHODS: All pediatric trauma patients with external fixation who were treated at our institution between 1998 and 2003 were included. The charts of 30 children (20 males; 10 females; mean age, 13.2 years; range, 7-19 years) with 37 episodes of external fixation were reviewed. The average duration of external fixation was 17.5 weeks (range, 1-94 weeks). Pin tract infections were graded using the Dahl classification. Bacterial cultures were obtained in case of drainage from the pin site. RESULTS: In 18 (48%) of 37 external fixations, no signs of infection occurred during the treatment period. In the remaining 19 (52%) external fixations, 35 episodes of infection were documented. Most infections were mild or moderate, whereas only 3 (9%) severe deep infections were noted (grade 5). Six (17%) infections healed with local application of rifamycin, whereas 27 (77%) of 35 infections were successfully treated with systemic antibiotics (cefuroxime, clindamycin). The remaining 2 infections (6%) required removal of a pin. CONCLUSIONS: Pin tract infection occurred in half of the patients who were treated with external fixations. Most of the pin site infections in the present series were mild and could be managed by local or systemic application of antibiotics. The occurrence of pin tract infections did not require a change of the method of stabilization.


Assuntos
Infecções Bacterianas/etiologia , Pinos Ortopédicos/efeitos adversos , Fixadores Externos/efeitos adversos , Fixação de Fratura/efeitos adversos , Adolescente , Adulto , Infecções Bacterianas/diagnóstico , Criança , Feminino , Humanos , Masculino
16.
Pediatrics ; 117(3): e374-9, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16510617

RESUMO

OBJECTIVES: This study focuses on the pattern of incidence, mechanisms, and circumstances of accident and injury in a series of pediatric patients who sustained dog bites. METHODS: In our retrospective survey, the medical charts of all children who were younger than 17 years and sought medical attention after a dog bite between 1994 and 2003 were reviewed. To obtain the total number of each dog breed in the administrative district, we analyzed 5873 files from the community dog registers. For establishment of a risk index, the representation of a dog breed among the total canine population was divided by the frequency of dog bites from this breed. RESULTS: A total of 341 children (mean age: 5.9 years) were identified. The annual incidence of dog bites was 0.5 per 1000 children between 0 and 16 years of age. Incidence was highest in 1-year-old patients and decreased with increasing age. The relative risk for a dog attack by a German shepherd or a Doberman was approximately 5 times higher than that of a Labrador/retriever or cross-breed. The vast majority (82%) of the dogs were familiar to the children. Most (322; 94%) of the children had injuries to 1 body region; in the remaining 19 (6%) children, up to 3 body regions were injured. Of 357 injuries, the face, head, and neck region was the leading site affected (50%). Inpatient treatment was required in 93 (27%) patients. CONCLUSIONS: Dog bites in children are frequent and influenced by the breed-related behavior of dogs, dog owners, children, and parents. Therefore, prevention strategies should focus on public education and training of dogs and their owners. Children who are younger than 10 years represent the high-risk group for dog attacks.


Assuntos
Mordeduras e Picadas , Cães , Adolescente , Animais , Áustria/epidemiologia , Mordeduras e Picadas/complicações , Mordeduras e Picadas/epidemiologia , Mordeduras e Picadas/terapia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino
17.
Am J Physiol Gastrointest Liver Physiol ; 290(6): G1203-10, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16469824

RESUMO

The acute phase of intestinal ischemia-reperfusion (I/R) injury is mediated by leukocytes and is characterized by oxidative stress and blood cell recruitment. Upregulation of angiotensin II type 1 receptors (AT1-R) has been implicated in the pathogenesis of conditions associated with oxidative stress. The AT1-R-antagonist Losartan (Los) attenuates leukocyte recruitment following I/R. However, the role of AT1-R in intestinal I/R injury and the associated platelet-leukocyte interactions remains unclear. The objective of this study was to define the contribution of AT1-R to I/R-induced blood cell recruitment in intestinal venules. Leukocyte and platelet adhesion were quantified by intravital microscopy in the small bowel of C57Bl/6 [wild-type (WT)] mice exposed to sham operation or 45 min of ischemia and 4 h of reperfusion. A separate WT group received Los for 7 days before gut I/R (WT-I/R + Los). AT1-R bone marrow chimeras that express AT1-R on the vessel wall but not blood cells also underwent I/R. Platelet and leukocyte adhesion as well as AT1-R expression in the gut microvasculature were significantly elevated after I/R. All of these responses were attenuated in the WT-I/R + Los group, compared with untreated I/R mice. A comparable abrogation of I/R-induced blood cell adhesion was noted in AT1-R bone marrow chimeras. I/R-induced platelet adhesion was unaltered in mice overexpressing Cu,Zn-SOD or mice deficient in NAD(P)H oxidase. These data suggest that although gut I/R upregulates endothelial expression of AT1-R, engagement of these angiotensin II receptors on blood cells is more important in eliciting the prothrombogenic and proinflammatory state observed in postischemic gut venules, through a superoxide-independent pathway.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/irrigação sanguínea , Microcirculação/metabolismo , Microcirculação/patologia , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Animais , Intestinos/patologia , Camundongos , Camundongos Endogâmicos C57BL
18.
Arterioscler Thromb Vasc Biol ; 26(2): 313-8, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16254200

RESUMO

OBJECTIVE: Hypercholesterolemia elicits a proinflammatory and prothrombogenic phenotype in the microvasculature that is characterized by activation and adhesion of blood cells. The angiotensin II receptor-1 antagonist Losartan prevents the induction of these responses. The objective of this study was to determine the relative contributions of blood cell-associated versus endothelium-associated AT1a-R to these hypercholesterolemia-induced microvascular alterations. METHODS AND RESULTS: Leukocyte adhesion and emigration and platelet adhesion were quantified by intravital microscopy in postcapillary venules. C57Bl/6 mice were placed on a normal (ND) or high-cholesterol (HCD) diet for 2 weeks. AT1a-R bone marrow chimeras that express AT1a-R on the vessel wall but not blood cells and AT1a-R knockouts were placed on HCD. Venular shear rate was comparable in all groups. Platelet and leukocyte adhesion and leukocyte emigration were significantly increased in HCD mice versus ND. Leukocyte recruitment was significantly reduced in the HCD-AT1a-R bone marrow chimera group, whereas platelet adhesion remained at HCD levels. However, in HCD-AT1a-R knockout mice, platelet and leukocyte adhesion were reduced to ND levels. CONCLUSIONS: These data indicate that the platelet-vessel wall adhesion elicited by hypercholesterolemia is mediated by AT1a-R engagement on the endothelial cell rather than the platelet, whereas leukocyte recruitment is mediated by blood cell-associated AT1a-R.


Assuntos
Endotélio Vascular/metabolismo , Hipercolesterolemia/imunologia , Hipercolesterolemia/metabolismo , Leucócitos/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo , Vasculite/metabolismo , Animais , Plaquetas/citologia , Plaquetas/metabolismo , Pressão Sanguínea , Transplante de Medula Óssea , Adesão Celular/imunologia , Colesterol/sangue , Endotélio Vascular/citologia , Endotélio Vascular/imunologia , Leucócitos/citologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microcirculação , Adesividade Plaquetária , Receptor Tipo 1 de Angiotensina/genética , Quimeras de Transplante , Vasculite/imunologia
19.
Hypertension ; 45(2): 209-15, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15655122

RESUMO

Hypercholesterolemia elicits an inflammatory response in the microvasculature that is accompanied by an increased expression of angiotensin II type-1 receptors (AT1-R) on platelets, leukocytes, and endothelial cells. AT1-R blockade attenuates inflammatory responses to angiotensin II (eg, adhesion molecule expression and reactive oxygen species production). We investigated whether AT1-R antagonism attenuates the platelet and leukocyte recruitment induced by acute hypercholesterolemia in postcapillary venules. Leukocyte and platelet adhesion and oxidative stress were quantified by intravital microscopy in cremaster muscle, and P-selectin and AT1-R expression was determined in mice placed on a normal diet (ND) or high-cholesterol diet (HCD) for 2 weeks. Platelet and leukocyte adhesion was significantly elevated by hypercholesterolemia. In HCD mice receiving losartan (HCD-Los) in drinking water, platelet and leukocyte recruitment was reduced to ND levels. Increased platelet adhesion was observed in HCD mice receiving platelets from HCD-Los mice, consistent with a direct beneficial action of losartan on the vessel wall. Hypercholesterolemia elicited an oxidative stress in venules and an increased expression of P-selectin and AT1-R. The oxidative stress and AT1-R upregulation were reduced by losartan, but the P-selectin response was not. We propose that AT1-R engagement contributes to the prothrombogenic and proinflammatory state induced in venules by hypercholesterolemia.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Hipercolesterolemia/complicações , Losartan/farmacologia , Trombose/prevenção & controle , Vasculite/prevenção & controle , Vênulas/efeitos dos fármacos , Animais , Plaquetas/metabolismo , Movimento Celular , Endotélio Vascular/metabolismo , Hipercolesterolemia/fisiopatologia , Leucócitos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Oxidantes/biossíntese , Selectina-P/metabolismo , Adesividade Plaquetária , Receptor Tipo 1 de Angiotensina/sangue , Receptor Tipo 1 de Angiotensina/metabolismo , Trombose/etiologia , Vasculite/etiologia , Vênulas/metabolismo
20.
Hypertension ; 43(5): 924-31, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15007038

RESUMO

There is a growing body of evidence that inflammation might play an important role in the initiation and progression of cardiovascular diseases (CVDs). The designation of CVD as a chronic inflammatory process is further supported by evidence that the risk factors for CVD cause endothelial cells throughout the vascular tree to assume an inflammatory phenotype. These activated endothelial cells characteristically exhibit oxidative stress and increased adhesiveness for circulating leukocytes. Although initial efforts to define the mechanisms underlying the inflammatory phenotype in diseased endothelial cells have focused on the linkage between oxidative stress and adhesion molecule activation/expression, recent work has implicated a variety of additional factors that can modulate the magnitude and/or nature of the inflammatory responses in CVD. Platelets, angiotensin II, and the CD40/CD40 ligand signaling system are gaining recognition as contributors to the pathogenesis of CVD. These factors appear to converge with known pathways that link oxidative stress with adhesion molecule expression and help to explain the apparent integration of coagulation with inflammation in CVD. These factors also hold the promise of offering multiple sites for therapeutic intervention in CVD.


Assuntos
Doenças Cardiovasculares/fisiopatologia , Inflamação/fisiopatologia , Angiotensina II/fisiologia , Animais , Plaquetas/fisiologia , Antígenos CD40/fisiologia , Ligante de CD40/fisiologia , Doenças Cardiovasculares/etiologia , Moléculas de Adesão Celular/fisiologia , Progressão da Doença , Endotélio Vascular/patologia , Endotélio Vascular/fisiopatologia , Humanos , Inflamação/complicações , Integrinas/fisiologia , Modelos Animais , Estresse Oxidativo , Sistema Renina-Angiotensina/fisiologia , Fatores de Risco , Trombofilia/etiologia , Trombofilia/fisiopatologia
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