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4.
Pneumologie ; 63(12): 718-25, 2009 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-19941265

RESUMO

The time delay between the start of respiratory symptoms and the correct diagnosis of alpha-1-antitrypsin (AAT) deficiency is often 6 to 8 years. Most patients are misdiagnosed as having COPD or asthma. Recent estimates suggest that only 15 % of patients have already been identified. The PiZZ genotype leads to severely decreased AAT serum concentrations, and is associated with a high risk of pulmonary emphysema. Disease manifestation is earlier in smokers than in non-smokers. Since cigarette smoke is able to reduce AAT activity by a factor of 2000, it can accelerate the progression of emphysema. Patients are therefore recommended to stop smoking. The EXACTLE study assessed the development of emphysema by means of CT densitometry in 77 patients with severe AAT deficiency over a period of 2.5 years. CT densitometry was able to detect the progressive loss of lung tissue, and it was found to be more sensitive than pulmonary function or quality of life variables. With weekly intravenous supplementation of alpha-1-antitrypsin, emphysema progressed more slowly compared to placebo (albumin) infusions. In Germany, of about 900 patients are currently receiving supplementation therapy with human AAT. The treatment is well tolerated and well accepted by the patients. Symptomatic treatment consists of long- and short-acting beta-agonists, anticholinergic bronchodilators, and inhaled corticosteroids. Alpha-1 centres provide particular expertise, and it is recommended that every patient should be seen in one of these specialised outpatient clinics.


Assuntos
Pneumologia/tendências , Deficiência de alfa 1-Antitripsina/diagnóstico , Deficiência de alfa 1-Antitripsina/terapia , Ensaios Clínicos como Assunto/tendências , Humanos , Deficiência de alfa 1-Antitripsina/genética
5.
Lab Anim ; 42(2): 222-30, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18435880

RESUMO

Airway access is needed for a number of experimental animal models, and the majority of animal research is based on mouse models. Anatomical conditions in mice are small, and the narrow glottic opening allows intubation only with a subtle technique. We therefore developed a microscopic endotracheal intubation method with a wire guide technique in mice anaesthetized with halothane in oxygen. The mouse is hung perpendicularly with its incisors on a thread fixed on a vertical plate. The tongue is placed with a pair of forceps between the left hand's thumb and forefinger and slightly pulled, while the neck and thorax are positioned using the third and fourth fingers. By doing so, the neck can be slightly stretched, which allows optimal visualization of the larynx and the vocal cords. To ensure a safe intubation, a fine wire guide is placed under vision between the vocal cords and advanced about 5 mm into the trachea. An intravenous 22G x 1 in. plastic or Teflon catheter is guided over this wire. In a series of 41 mice, between 21 and 38 g, the success rate for the first intubation attempt was >95%. Certainty of the judgement procedure was 100% and success rate was higher using the described method when compared with a transillumination method in a further series. The technique is safe, less invasive than tracheostomy and suitable for controlled ventilation and pulmonary substance application.


Assuntos
Intubação Intratraqueal/veterinária , Camundongos Endogâmicos BALB C/cirurgia , Camundongos Endogâmicos C3H/cirurgia , Camundongos Knockout/cirurgia , Animais , Intubação Intratraqueal/métodos , Intubação Intratraqueal/normas , Camundongos , Estudos Prospectivos , Distribuição Aleatória , Transiluminação/veterinária
6.
Surg Endosc ; 20(10): 1607-13, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16823647

RESUMO

BACKGROUND: Postoperative systemic immune function is suppressed after open abdominal surgery, as compared with that after minimally invasive abdominal surgery. As a first line of defense, peritoneal macrophages (PMo) and polymorphonuclear neutrophil granulocytes (PMNs) are of primary importance in protecting the body from microorganisms. Previous studies have shown changes in these cell populations over time after open versus laparoscopic surgery. This study aimed to investigate the dynamics of cell recruitment and clearance of peritoneal cells. METHODS: Female NMRI mice (33 +/- 2 g) were randomly assigned to carbon dioxide (CO2) or air insufflation. Intravasal cells with phagocytic capabilities were selectively stained by intravenous injection of the fluorescent dye PKH26 24 h before surgery. Gas was insufflated into the peritoneal cavity through a catheter, and the pneumoperitoneum was maintained for 30 min. Peritoneal lavage was performed 1, 3, 8, or 24 h after surgery. Apoptotic cells were assessed by flow cytometry using a general caspase substrate. RESULTS: The total peritoneal cell count did not differ between groups. The PKH26-positive PMo level was significantly increased after CO2, as compared with air, at 1 h and 24 h. The ratio of apoptotic PMo did not differ between the groups. In the peritoneal lavage, polymorphonuclear leukocytes (PMNs) were tripled in the air group, as compared with the CO2 group, whereas the ratio of apoptotic PMNs was significantly decreased. There was a higher fraction of PKH26-positive PMNs after air exposure, as compared with that after CO2. CONCLUSIONS: Air exposure triggered a higher transmigration rate of PMNs from the blood compartment into the peritoneal cavity and decreased PMN apoptosis, as compared with CO2. The lower proportion of PKH26-positive peritoneal macrophages in the air group might have been attributable to a higher inflammatory stimulation than in the CO2 group, leading to increased emigration of PMo to draining lymph nodes. All the findings underscore a complex cell-specific regulation of cell recruitment and clearance in the peritoneal compartment.


Assuntos
Ar , Dióxido de Carbono/administração & dosagem , Neutrófilos/fisiologia , Peritônio/citologia , Pneumoperitônio Artificial , Animais , Apoptose , Movimento Celular , Feminino , Citometria de Fluxo , Corantes Fluorescentes , Laparoscopia , Contagem de Leucócitos , Camundongos , Compostos Orgânicos , Fagocitose
7.
Br J Cancer ; 94(4): 524-31, 2006 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-16450002

RESUMO

Circulating endothelial cells (CECs) as well as bone-marrow-derived endothelial precursor cells (EPC) play an important role in neovascularisation and tumour growth. To study the impact of neoadjuvant chemotherapy on the amounts of CEC and their precursor cells, mature CEC and their progenitors were quantified by flow cytometry in peripheral blood of breast cancer patients during anthracycline and/or taxane based neoadjuvant chemotherapy and subsequent surgery in comparison to age-matched healthy controls. Cell numbers were tested for correlation with serum levels of angiopoietin-2, erythropoietin, endostatin, endoglin, VEGF and sVCAM-1 as well as clinical and pathological features of breast cancer disease. Circulating endothelial cells were significantly elevated in breast cancer patients and decreased during chemotherapy, whereas EPC (CD34+/VEGFR-2+) as well as their progenitor cell population CD133+/CD34+ and the population of CD34+ stem cells increased. Concomitantly with the increase of progenitor cells an increase of VEGF, erythropoietin and angiopoietin-2 was observed. These data suggest that chemotherapy can only reduce the amounts of mature CEC, probably reflecting detached cells from tumour vessels, whereas the EPC and their progenitors are mobilised by chemotherapy. Since this mobilisation of EPC may contribute to tumour neovascularisation an early antiangiogenic therapy in combination with chemotherapy could be beneficial for the success of cancer therapy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/fisiopatologia , Células Endoteliais , Neovascularização Patológica/fisiopatologia , Células-Tronco , Adulto , Inibidores da Angiogênese/uso terapêutico , Biomarcadores Tumorais/sangue , Estudos de Casos e Controles , Movimento Celular , Progressão da Doença , Feminino , Citometria de Fluxo , Substâncias de Crescimento/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante
10.
Lab Anim ; 39(2): 209-14, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15901364

RESUMO

Mouse skin transplantation is an established in vivo model used to investigate the T-cell-mediated immune response of acute allograft rejection. The critical endpoint of this model is complete rejection of the allograft. However, visual judgement of this end stage of rejection is an arbitrary process and difficult to standardize. To overcome this problem, we established a monitoring method based on digital photography. Serial pictures from skin allografts of individual animals (C57BL/6 on BALB/c) were taken with a digital camera mounted on a microsurgical microscope. Thereby, the description and the correct assessment of early stages of rejection were possible due to the magnification of grafts by the microscope. Rejection scores were introduced to describe different stages from retained to completely rejected grafts. With cyclosporine A as a standard immunosuppressive treatment, we showed that early stages of skin rejection were unambiguously identified. This procedure allows the earlier termination of the experiment and reduction of animal distress, and it can be re-evaluated anywhere and any time after completion.This study demonstrates the suitability of monitoring experimental skin allograft rejection by digital photography, entailing several refinements in animal experimentation, both for the researcher and for the animal.


Assuntos
Rejeição de Enxerto/patologia , Transplante de Pele/fisiologia , Transplante Homólogo/fisiologia , Animais , Ciclosporina , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Monitorização Fisiológica/métodos , Fotografação
11.
Surg Endosc ; 19(7): 958-63, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15920692

RESUMO

BACKGROUND: The authors previously demonstrated postoperative preservation of the immune function measured by delayed-type skin reaction and tumor growth after laparoscopic surgery, as compared with laparotomy. For further elucidation of the origin of the demonstrated immune preservation, peritoneal macrophage (PMo) function was investigated 1 h after different surgical procedures. METHODS: Female NMRI mice were divided into five groups: anesthesia only, abdominal skin incision, laparotomy, peritoneal carbon dioxide (CO2) insufflation, and peritoneal air insufflation. Escherichia Coli phagocytosis, tumor necrosis factor-alpha (TNF-alpha), transforming growth factor-beta1 (TGF-beta1), and interleukin-10 (IL-10) release of isolated PMo were investigated. RESULTS: All invasive interventions reduced the PMo phagocytosis by factors of approximately 2 to 4.7, as compared with the sham control group. Spontaneous ex vivo TNF-alpha release was significantly increased whenever the abdominal cavity was exposed to ambient air. The macrophage's ability to release TNF-alpha after E. coli exposure was diminished in the abdominal air exposure groups, as compared with the CO2 insufflation group. CONCLUSION: Reduced phagocytosis 1 h after surgical interventions suggests a contribution of PMo to the altered immune function. When exposed to CO2, PMo show a decreased basal TNF-alpha release. However, PMo also show an increased TNF-alpha release after a second immune stimulation (E. coli), suggesting a greater competency of interaction in an immune defense reaction after CO2 exposure.


Assuntos
Laparoscopia , Laparotomia , Macrófagos Peritoneais/fisiologia , Pneumoperitônio Artificial , Animais , Dióxido de Carbono , Citocinas/análise , Escherichia coli/fisiologia , Feminino , Insuflação/métodos , Macrófagos Peritoneais/imunologia , Camundongos , Camundongos Endogâmicos , Modelos Animais , Fagocitose , Distribuição Aleatória , Fator de Necrose Tumoral alfa/metabolismo
12.
Eur Respir J ; 25(2): 289-94, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15684293

RESUMO

Effective treatment of respiratory symptoms, airway inflammation and impairment of lung function is the goal of any asthma therapy. Although montelukast has been shown to be a possible add-on therapy for anti-inflammatory treatment in older children, its efficacy in infants and young children is not well known. The aim of this study was to investigate its effect in infants and young children with early childhood asthma. In a prospective randomised double-blind placebo-controlled study, 24 young children (10-26 months) with wheeze, allergy and a positive family history of asthma consistent with the diagnosis of early childhood asthma were randomised to receive montelukast 4 mg or placebo. The forced expiratory volume in 0.5 seconds (FEV0.5) was measured using the raised volume rapid thoracic compression technique, and fractional exhaled nitric oxide (FeNO) and symptom scores were determined. No change was noted in FEV0.5, FeNO or symptom score in the placebo group following the treatment period. In contrast, significant improvements in mean+/-SD FEV0.5 (189.0+/-37.8 and 214.4+/-44.9 mL before and after treatment, respectively), FeNO (29.8+/-10.0 and 19.0+/-8.5 ppb) and median symptom score (5.5 and 1.5) were noted following treatment with montelukast. In conclusion, montelukast has a positive effect on lung function, airway inflammation and symptom scores in very young children with early childhood asthma.


Assuntos
Acetatos/uso terapêutico , Antiasmáticos/uso terapêutico , Asma/tratamento farmacológico , Quinolinas/uso terapêutico , Administração por Inalação , Análise de Variância , Asma/metabolismo , Asma/fisiopatologia , Ciclopropanos , Método Duplo-Cego , Feminino , Volume Expiratório Forçado/efeitos dos fármacos , Humanos , Lactente , Masculino , Óxido Nítrico/metabolismo , Estudos Prospectivos , Estatísticas não Paramétricas , Sulfetos , Resultado do Tratamento
13.
Eur Respir J ; 19(1): 54-60, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11843327

RESUMO

Lung volume reduction surgery (LVRS) improves dyspnoea, pulmonary function, and physical performance in patients with severe pulmonary emphysema. This study investigated the impact of LVRS on health-related quality of life (HRQL) over a 2-yr period following surgery. Thirty-nine consecutive patients were prospectively assessed before LVRS, and followed over 24 months postoperatively. The assessments included pulmonary function, dyspnoea (Medical Research Council (MRC) dyspnoea score), 6-min walking distance (6MWD) and HRQL using the Short Form 36-item questionnaire (SF-36). Several domains of SF-36 improved considerably over 2 yrs after surgery: Physical Functioning: 39 +/- 4 (mean +/- SEM) versus 16 +/- 2 (p<0.01); Vitality: 51 +/- 3 versus 32 +/- 3 (p<0.01); Social Functioning: 72 +/- 4 versus 51 +/- 5 (p<0.01). Also, improvements in pulmonary function (forced expiratory volume in one second (FEV1): 27 +/- 1% predicted, residual volume (RV)/total lung capacity (TLC): 0.65 +/- 0.01), 6 MWD (274 +/- 16 m) and dyspnoea (MRC: 3.9 +/- 01) were sustained for up to 2 yrs after LVRS (FEV1 36 +/- 2% pred, RV/TLC: 0.58 +/- 0.02; 6 MWD: 342 +/- 19 m; MRC: 2.0 +/- 0.2; p<0.05). In patients with severe emphysema, lung volume reduction surgery had positive effects on health-related quality of life and pulmonary function over 2 yrs.


Assuntos
Pneumonectomia , Enfisema Pulmonar/cirurgia , Qualidade de Vida , Dispneia/fisiopatologia , Feminino , Seguimentos , Volume Expiratório Forçado , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Enfisema Pulmonar/fisiopatologia , Inquéritos e Questionários
14.
Artigo em Inglês | MEDLINE | ID: mdl-12701434

RESUMO

Hot pepper (Capsicum annuum. L.) is a traditionally and economically important spice crop in Ethiopia. Chronic infection with viruses is reported as major constraint, that often force farmers to ban its production. However, epidemiological studies on these viruses are lacking in the country. Knowledge of the weed flora as virus reservoir is essential to reduce the spread of plant viruses. The potential role of some frequently and abundantly occurring weed species as host plants for Capsicum viruses was therefore investigated. Surveys were conducted during the 2000/2001 cropping- and off-season. Samples of various weed species revealing virus symptoms were collected from different districts. Collection was done from inside and at the border of pepper cropped and fallow fields. It was also performed along road sides and irrigation channels. The identity of the collected isolates was established based on serology, electron microscopy and host range studies. Moreover, seeds were collected from natural populations of the most prevalent weeds, namely Datura stramonium and Nicandra physalodes. They were grown under glass house conditions and tested for their ability to host viruses. To verify their role further, healthy seedlings from these weeds were artificially inoculated with all viruses isolated from weeds and Capsicum leaf samples. Natural infection of different Potyviruses with an average incidence of 33% in the weed samples were the most dominant. In addition, the occurrence of Cucumber mosaic virus, Tomato mosaic virus and Potato virus X in these weeds was demonstrated. However, none of the isolated viruses was found to be seed borne in the tested weed species and pepper crop (var.Mrkofanna) under glass house conditions. Recently, there was an explosion in population size of some solanaceous weeds, particularly Datura and Nicandra species in the area. The presence of infected weeds throughout the year means, that they are an important reservoir and source for secondary spread. It is suggested therefore, that a rigorous weed control is an important step to reduce the incidence of viruses infecting Capsicum in the area.


Assuntos
Capsicum/virologia , Doenças das Plantas/virologia , Vírus de Plantas/isolamento & purificação , Solanaceae/virologia , Etiópia , Microscopia Eletrônica , Vírus de Plantas/ultraestrutura
15.
Am J Respir Crit Care Med ; 163(5): 1171-5, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11316655

RESUMO

Part of the functional benefit provided by lung volume reduction surgery (LVRS) may be related to improvement in respiratory muscle function resulting from changes in diaphragm dimension and configuration. To study these changes, we obtained 3D reconstructions of the muscle using spiral computed tomography in 11 patients with severe emphysema before and 3 mo after surgery, and in 11 normal subjects matched for sex, age, height, and weight. Bilateral LVRS was performed by thoracoscopy in eight patients and by sternotomy in three patients. Acquisitions were made in the supine posture at relaxed FRC, midinspiratory capacity, and TLC. On average, LVRS produced a 51 +/- 11% increase in FEV(1) and a 30 +/- 4% decrease in FRC. The total surface area of the diaphragm (A(di)) and of the zone of apposition (A(ap)) at FRC increased by 17 +/- 4% and 43 +/- 8%, respectively, but the surface area of the dome did not change. Compared with the values recorded in the normal subjects, postoperative values of A(di) and A(ap) at FRC were reduced by 11% (p < 0.05) and 24% (p < 0.005), respectively. The curvature of the dome increased at TLC in the left sagittal plane, but was otherwise unaffected by the procedure. We conclude that LVRS substantially increases A(di) and A(ap), but does not significantly improve diaphragm configuration at FRC.


Assuntos
Pneumonectomia , Enfisema Pulmonar/cirurgia , Antropometria , Diafragma/diagnóstico por imagem , Feminino , Capacidade Residual Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Enfisema Pulmonar/fisiopatologia , Mecânica Respiratória , Tomografia Computadorizada por Raios X , Capacidade Pulmonar Total , Resultado do Tratamento
17.
J Pharmacol Exp Ther ; 297(1): 128-32, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11259536

RESUMO

In septic shock excessive nitric oxide and superoxide are produced, thus generating peroxynitrite. This study investigates whether and how intravasal peroxynitrite causes lung dysfunction. To generate peroxynitrite, isolated and ventilated rat lungs were perfused blood-free in a pressure-constant, recirculating mode with hypoxanthine/xanthine oxidase plus sodium nitroprusside. Airway and vascular resistance, and release of thromboxane A2, prostacyclin, and endothelin-1 were assessed over 200 min. Peroxynitrite generation, as demonstrated by oxidation of the marker 2',7'-dichlorodihydrofluorescein diacetate, caused broncho- and vasoconstriction starting after 100 min. Both reactants alone, i.e., NO. or O2, had no effect. The thromboxane A2/prostaglandin H2 receptor antagonist BM13.177 did not affect peroxynitrite-induced broncho- and vasoconstriction. Combined endothelin(A/B) (ET(A/B)) receptor antagonism (BQ123 plus BQ788) prevented broncho- and vasoconstriction more effectively than the ET(A) receptor antagonist BQ123 alone. In tissue from lungs exposed to peroxynitrite, significantly increased amounts of endothelin-1 were detected. This study identifies endothelin-1 rather than prostanoids as a distal mediator induced by the reaction product of superoxide and nitric oxide, i.e., peroxynitrite. It is concluded that 1) endothelin-1 is a causal mediator of peroxynitrite-induced acute rat lung injury, and 2) peroxynitrite-induced broncho- and vasoconstriction are mediated by both ET(A) and ET(B) receptors.


Assuntos
Endotelinas/fisiologia , Pulmão/efeitos dos fármacos , Nitratos/toxicidade , Animais , Broncoconstrição/efeitos dos fármacos , Feminino , Nitratos/metabolismo , Oligopeptídeos/farmacologia , Peptídeos Cíclicos/farmacologia , Perfusão , Piperidinas/farmacologia , Prostaglandina-Endoperóxido Sintases/fisiologia , Ratos , Ratos Wistar , Vasoconstrição/efeitos dos fármacos
18.
J Thorac Cardiovasc Surg ; 120(6): 1078-84, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11088029

RESUMO

BACKGROUND: The nonspecific immune response with activation of the complement system and polymorphonuclear leukocytes is important for the mediation of reperfusion injury after lung transplantation. In this study, we investigated the combined blockade of the complement system and leukocyte adhesion by a novel drug combining soluble complement receptor type 1 (sCR1, CD35) with the selectin ligand sialyl Lewis X (sLe(X), CD15s) synthesized to sCR1sLe(X). Both sCR1 and sCR1sLe(X) were supplied by AVANT Immunotherapeutics, Inc, Needham, Massachusetts. METHODS: Orthotopic allogeneic single left lung transplantation was performed in male rats (Brown Norway to Fischer F344; n = 5 in all groups) after a total ischemic time of 20 hours. Recipients received either no specific treatment (control) or administration of sCR1 (10 mg/kg) or sCR1sLe(X) (10 mg/kg) 15 minutes before reperfusion by intracardiac injection. Twenty-four hours after reperfusion, the native contralateral lung was occluded to assess gas exchange of the graft only. In additional animals (5 per group), lung tissue was frozen 24 hours after reperfusion and assessed for myeloperoxidase activity as a measurement of neutrophil migration into the graft and thiobarbituric acid reactive substances to quantify lipid peroxidation. RESULTS: Graft function as assessed by arterial PO (2) in recipients treated with sCR1sLeX was superior not only to that of controls (383 +/- 53 vs 56 +/- 7 mm Hg, P =. 000095) but also to that of animals treated with sCR1 (243 +/- 45 mm Hg, P =.031). This improvement was confirmed by significant reduction of neutrophil migration (0.33 +/- 0.05 vs control, 1.0 +/- 0.09 DeltaOD/mg/min, P =.0000024) and lipid peroxidation (6.2 +/- 0. 38 vs control, 10.6 +/- 0.54 pmol/g, P =.00021). CONCLUSIONS: Our data indicate that combined inhibition of complement activation and leukocyte adhesion with sCR1sLe(X) reduces reperfusion injury significantly and that both mechanisms are effectively inhibited in this model.


Assuntos
Proteínas Inativadoras do Complemento/uso terapêutico , Modelos Animais de Doenças , Transplante de Pulmão/efeitos adversos , Receptores de Complemento/uso terapêutico , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/prevenção & controle , Animais , Ativação do Complemento/efeitos dos fármacos , Ativação do Complemento/imunologia , Proteínas Inativadoras do Complemento/imunologia , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Leucócitos/efeitos dos fármacos , Leucócitos/imunologia , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/imunologia , Transplante de Pulmão/imunologia , Masculino , Camundongos , Neutrófilos/efeitos dos fármacos , Neutrófilos/imunologia , Ratos , Ratos Endogâmicos F344 , Receptores de Complemento/imunologia , Traumatismo por Reperfusão/imunologia , Traumatismo por Reperfusão/patologia , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Fatores de Tempo , Transplante Homólogo
19.
AJNR Am J Neuroradiol ; 21(9): 1654-60, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11039345

RESUMO

BACKGROUND AND PURPOSE: CT is a frequent examination that is performed using ionizing radiation. We sought to assess image-quality changes on CT scans of the head when the radiation dose is reduced by changing tube current and kilovoltage. METHODS: A formalin-fixed cadaver was examined in conventional and helical mode by use of two CT-scanners. Surface dose was measured with standard scanning parameters, and after reduction of tube current and kilovoltage. Five experienced examiners independently evaluated subjective image quality. RESULTS: In the conventional mode, the highest surface dose was 83.2 mGy (scanner 1: helical mode, 55.6 mGy), and 66.0 mGy (scanner 2: helical mode, 55.9 mGy). By changing kVp and mAs, a dose reduction of up to 75% (scanner 1), and 60% (scanner 2) was achieved. No observable differences in image quality between scans obtained with doses from 100% to 60% of standard settings were noted. Ten of 20 images obtained with the highest dose and 13 of 20 images obtained with lowest dose (19-29.4 mGy) were reliably identified by subjective quality assessment. Scans produced with a surface dose of less than 30 mGy were judged uninterpretable. CONCLUSION: Standard parameters used in cranial CT are oriented toward best image quality. A dose reduction up to 40% may be possible without loss of diagnostic image quality.


Assuntos
Cabeça/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Cadáver , Humanos , Doses de Radiação , Intensificação de Imagem Radiográfica
20.
Chest ; 117(6): 1560-7, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10858383

RESUMO

STUDY OBJECTIVE: To evaluate the activity and evolution in the field of lung volume reduction surgery (LVRS) performed at surgical centers in Europe. BACKGROUND: LVRS is a novel surgical therapy with the potential to improve lung function, exercise performance, and quality of life in selected patients suffering from severe pulmonary emphysema. METHODS: Questionnaire addressed to 75 European thoracic surgical centers presumed to perform LVRS, and review of the literature. RESULTS: Of 45 responding centers, 42 centers in 17 countries covering a population of 423 million reported performing LVRS. Until the end of 1998, 1,120 patients were reported to have undergone LVRS, corresponding to 2.6 patients/million inhabitants. Thirty-one of 40 centers (78%) perform the operation bilaterally. Most centers (83%) evaluate their activity prospectively. The average perioperative mortality rate of 4.1% is moderate. The most commonly utilized technique is video-assisted thoracoscopy, which is most frequently performed bilaterally. Two thirds of the centers treat patients with alpha(1)-antitrypsin deficiency, and half of the centers will consider patients with homogenous morphology of emphysema on CT scan for LVRS. Half of the centers also perform lung transplantation. The five largest centers have operated on 49% of all LVRS patients assessed by this survey. CONCLUSIONS: LVRS is performed at few thoracic surgical centers throughout Europe, with a large variation in the operative activity between different regions. Half of the centers also perform lung transplantation. Between 1995 and 1997, the number of LVRS procedures performed per year nearly tripled but has reached a plateau since then. As five centers perform nearly half the total number of operations, an optimal exchange of knowledge with smaller centers seems important.


Assuntos
Pneumonectomia , Enfisema Pulmonar/cirurgia , Europa (Continente) , Mortalidade Hospitalar , Humanos , Avaliação de Processos e Resultados em Cuidados de Saúde , Cuidados Paliativos , Complicações Pós-Operatórias/etiologia , Enfisema Pulmonar/mortalidade , Taxa de Sobrevida
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