Investigation of an apodized imaged Hartmann wavefront sensor.

Quantitative wavefront measurements are demonstrated using a Hartmann mask re-imaged onto a camera. The wavefront is reconstructed using standard algorithms applied to the difference of beamlet centroids determined from fluence distributions obtained for two different longitudinal locations of the mask. The wavefront of the optical wave in the object plane is measured independently of imaging-system collimation. Apodization obtained with spatially dithered distributions of small transparent or opaque pixels improves the measurement accuracy by reducing the spatial-frequency content of the mask holes. Simulations and experiments demonstrate the excellent accuracy of this diagnostic over a wide range of parameters, making it suitable, for example, to characterize laser systems.

Experimental discrimination of ion stopping models near the Bragg peak in highly ionized matter.

The energy deposition of ions in dense plasmas is a key process in inertial confinement fusion that determines the α-particle heating expected to trigger a burn wave in the hydrogen pellet and resulting in high thermonuclear gain. However, measurements of ion stopping in plasmas are scarce and mostly restricted to high ion velocities where theory agrees with the data. Here, we report experimental data at low projectile velocities near the Bragg peak, where the stopping force reaches its maximum. This parameter range features the largest theoretical uncertainties and conclusive data are missing until today. The precision of our measurements, combined with a reliable knowledge of the plasma parameters, allows to disprove several standard models for the stopping power for beam velocities typically encountered in inertial fusion. On the other hand, our data support theories that include a detailed treatment of strong ion-electron collisions.

Maximum Proton Energy above 85 MeV from the Relativistic Interaction of Laser Pulses with Micrometer Thick CH_{2} Targets.

We present a study of laser-driven ion acceleration with micrometer and submicrometer thick plastic targets. Using laser pulses with high temporal contrast and an intensity of the order of 10^{20} W/cm^{2} we observe proton beams with cutoff energies in excess of 85 MeV and particle numbers of 10^{9} in an energy bin of 1 MeV around this maximum. We show that applying the target normal sheath acceleration mechanism with submicrometer thick targets is a very robust way to achieve such high ion energies and particle fluxes. Our results are backed with 2D particle in cell simulations furthermore predicting cutoff energies above 200 MeV for acceleration based on relativistic transparency. This predicted regime can be probed after a few technically feasible adjustments of the laser and target parameters.

[The surgical repair of thoracic deformities in adult patients]. / Chirurgische Behandlung von Brustkorbdeformitäten bei erwachsenen Patienten.

The authors' experience with the surgical repair of thoracic deformities in 45 adult patients is reported. The most frequent deformity was pectus excavatum (n = 42), the asymmetric form of which was observed in 59 % of our patients. The patients were treated by means of a modified Ravitch method, with the retrosternal introduction of a Jensen strut. The strut was left in place for one year and then was removed via a small incision. With the exception of two cases of postoperative pneumothorax, no other postoperative complications were seen and no patient died. In the follow-up 1 year after removal of the Jensen strut, no recurrent deformities were observed in 36 patients. On the basis of these results, we consider the described technique as the method of choice in the treatment of congenital thoracic deformities in adult patients.

The value of 18-FDG PET/CT imaging in a patient with atypical metastatic colorectal cancer--case report: 18-FDG PET/CT in colorectal cancer.

BACKGROUNDS: Cancer metastasis to skeletal muscle is very rare. Lung cancer, renal cell carcinoma and malignant melanoma have been reported as the most frequent primary tumours. Diagnosis of muscle metastasis from other primary cancer sites is more than problematic. CASE: In this paper we report a case of metastasis of colorectal cancer in a 44-year-old man who underwent left-sided hemicolectomy due to the tumour mass in his left colic flexure followed by liver metastasectomy and cryocautery of the non-resectable metastasis in the VII segment. Subsequently, the patient was treated with two lines of chemotherapy. However, shortly after initiation of the second chemotherapy line he started to suffer from unbearable pain in the lumbosacral region. Neither a whole spinal cord MRI nor abdominal CT scan and scintigraphy explained the origin of the pain. Finally, PET/CT examination clarified the origin of the pain and showed massive hypermetabolic metastatic lesions in the muscles, further confirmed by autopsy. CONCLUSION: Thus, among the different imaging techniques, FDG PET/CT enables the detection of metabolically highly active tumour cells, undetectable by other conventional imaging means.

Tracheal stenosis complicated with tracheoesophageal fistula.

OBJECTIVE: The aim of the present study was to evaluate the results of surgical treatment in patients with simultaneous occurrence of postintubation tracheal stenosis (TS) and tracheoesophageal fistula (TEF). METHODS: In the group of 51 patients with postcannulation tracheal stenosis who underwent segmental resection, TEF was identified simultaneously in five (10%) of them. The mean age of the TS-TEF patients was 43 years (range 35-60 years). The patients underwent a single-stage operation during which TEF was sealed and resection of the stenotic tracheal segment was performed. RESULTS: The cause of TEF and of TS was artificial pulmonary ventilation by tracheostomy tube (n=4) or by endotracheal tube (n=1) with a simultaneous insertion of nasogastric tube. In one of the patients with tracheostomy the fistula resulted from an injury to the pars membranacea tracheae and the esophageal wall during tracheostomy. All the patients were respiring spontaneously before the surgical treatment. The mean length of the fistula was 24.0 mm (range 15-30 mm), the fistulae were located at the junction of the upper and middle third of the trachea. The mean length of the resected tracheal segment was 29.6 mm (range 26-32 mm). Postoperative complications were not observed in the group of the TS-TEF patients, none of them died. CONCLUSIONS: The method of choice of the surgical treatment of TEF associated with TS is a single-stage procedure in the patient who respires spontaneously.

[Role of morphology in medical education, clinical practice and research]. / Postavení morfologie ve výuce medicíny a v klinické praxi a výzkumu.

Rapid development of molecular biology, biochemistry, physiology and other sciences has diminished the previously dominant role of morphology in the theoretical part of medical studies. Morphology, closely related to various disciplines, should, however, be included in clinical lectures. Changes in the curricula would require concise and well-structured textbooks, based on recent clinico-morphological studies, for the theoretical parts of both medical and allied health care study programmes. Comprehensive textbooks are still necessary for the specific needs of clinicians and researches.

[Topical fibrinolysis with streptokinase in coagulated hemothorax]. / Lokální fibrinolýza koagulovaného hemotoraxu streptokinázou.

Local fibrinolysis using streptokinase was used in two patients with an organizing extensive haemothorax. In both patients the coagula were dissolved and the pleural cavity was effectively evacuated by means of a drain without the necessity of an extensive surgical intervention. The authors did not record any side-reactions to the local administration of streptokinase. In the authors' opinion proper timing is important for achieving a satisfactory effect of local fibrinolysis. Fibrinolysis cannot be used in case of clinical signs of proceeding haemorrhage or closely after its termination.

Bronchial carcinoid tumors: long-term outcome after surgery.

The objective of the present study was to evaluate clinical condition and results of surgical treatment of patients with typical and atypical bronchial carcinoids. The study was based on retrospective analysis of a total of 96 patients (mean age 47.3 year, age range 21-76, 44 men and women 52), who were surgically treated for bronchial carcinoid between 1985-2001. We assessed symptomatology of the disease, type of surgical intervention, tumor histology and staging, and postoperative 5-year and 10 year survival rates. The main sign of disease was respiratory inflammation. The carcinoid syndrome was not found in any patient. Most patients (n=68) were operated for central form of the tumor. The micromorphological tumor diagnosis was established prior to surgery in 76.5% patients with the central form of carcinoid. Surgical treatment included lobectomy (n=49), bronchoplastic procedure (n=14), sleeve lobectomy (n=9), atypical resection and segmentectomy (n=11), pneumonectomy (n=7) and tumor enucleation (n=5). Histological analysis revealed typical carcinoid in 77 cases (80.2%) and atypical carcinoid in 19 (19.8%). Lymph nodes (N1 and/or N2) were examined by histology in 84 patients and lymph node metastases were found in 13 (19.4%) of 67 patients with typical carcinoid and in 5 cases (29.4%) of 17 with atypical carcinoid. In the postoperative period on patient died from embolism to the arteria pulmonalis. Postoperative complications (atelectasis, prolonged air leak, bronchopleural fistula) were observed in 11.4% of patients. Tumor relapse occurred only in two patients with typical carcinoid. Postoperative 5-year and 10-year rates amounted to 98.6% and 87.3%, respectively, in typical carcinoid 94.5% and 73.5% in atypical carcinoid. The survival rates of patients with typical and atypical bronchial carcinoids were not significantly different (p>0.05). The surgical management is the treatment of choice in bronchial carcinoids. Results of this study indicate that the 5-year survival in patients with either histological type of bronchial carcinoid is excellent and the prognosis of operated patients is very good even in the case of regional lymph nodes infiltration by the tumors.

[Resection of the trachea for cicatrical stenosis]. / Trachealresektion bei Narbenstenosen.

UNLABELLED: Tracheal stenosis represents a serious complication of tracheostomy or of endotracheal intubation. The objective of this article was to evaluate the results of resective therapy of patients with tracheal stenosis. METHODS: In 41 patients treated by tracheal resection for tracheal stenosis the diagnosis was established by bronchoscopy, tracheal tomography or CT. The following parameters were evaluated: the reasons for artificial pulmonary ventilation, basic parameters of stenosis (site of stenosis, length, diameter), the relationship between the duration of cannulation and asymptomatic interval, and postoperative complications. RESULTS: The most frequent reason for cannulation was trauma (n = 23), most patients were cannulated for 4-5 weeks (n = 16), the symptoms of stenosis appeared mostly within 4-5 weeks (n = 11) after decannulation. The asymptomatic interval was longer in patients with longer periods of cannulation (p < 0.01) than in patients with a shorter cannulation period. The most frequent site of stenoses was the medium third of the trachea (n = 22). The longest resected section measured 60 mm. In 3 patients (7.3 %) a tracheoesophageal fistula was found together with the stenosis. In 3 patients (7.3 %) restenosis appeared. Tracheocutaneous fistula with osteomyelitis of the sternum developed in one patient. Granulation tissue on the anastomosis site (n = 4, 9.7 %) was treated by laser or disappeared spontaneously. None of the patients died within 30 days after operation. CONCLUSION: Resection is the optimum therapeutic method for tracheal stenosis with low postoperative mortality and a small number of postoperative complications. Successful tracheal resection is a definitive solution in comparison with stent placement.

[Mechanical loading of the human femoral neck]. / Mechanické namáhání krcku femuru cloveka.

PURPOSE OF THE STUDY: The aim of the study is to explain what is the actual loading of human proximal femur. MATERIAL: Measuring of stress is based on 5 femurs of normal shape (bones obtained from dissection and ossuary). In order to determine the direction of the resultant force the authors used 30 ossuary bones of different age but of analogical shape. METHODS: By means of their own graphic method the authors identified the direction of appositional growth of femoral neck which contains with the longitudinal diaphyseal axis the angle of 26 degrees (alpha angle). The value of the angle is identical with the direction of the resultant force acting on the femoral head in vivo. Tensometric method was used for the measuring of stress on the medial and lateral surfaces of femoral neck during loading in direction of the determined resultant force. Linear strain gauges of Hottinger type were used for the measuring and Instron apparatus was applied for biomechanical analysis in which femoral heads were loaded by a standard force of 50 kg, first in the direction of femoral diaphyseal axis and then gradually (always by 5 degrees) in the divergence from the diaphyseal axis up to 50 degrees. RESULTS: Appositional growth of femoral neck with regard to the longitudinal diaphyseal axis is progressing under the alpha angle (alpha = 26 degrees), which corresponds to the direction of the resultant force. The value of the compression stress on the medial surface of the neck ranged between--165 and -300 microstrain (mean value -239 microstrain). On the lateral surface there is a tension stress ranging between +20 up to +140 microstrain (main value +64 microstrain). The ratio of stress on both sides (surfaces) was 3.8:1. The point of zero stress is located in the lateral part of the neck, i.e. in the area of lateral trajectorial system of cancellous bone. DISCUSSION: The method of measuring of the direction of the resultant force on the basis of the bone development (on the basis of superposition of successive growth stages) is despite certain inaccuracies a correct procedure. The alpha angle (alpha = 26 degrees) identified by the authors corresponds with Pauwels' calculation (24 degrees) and Bergman's findings (22 degrees up to 27 degrees). The identified values of stress show that the opinion on a purely axial loading of the neck is wrong and has to be corrected. Femur is not exposed in the frontal plane to the action of the resultant force only in one direction as supposed e.g. by Pauwels but the direction of the resultant force oscillates within a limited extent from different directions. It means that the lateral wall of femoral neck is exposed to alternating both tensile and compression loading. CONCLUSION: The presented work allows to specify the opinions on the way of loading of human proximal femur. Our experiments have shown that apart from axial pressure the femoral neck is exposed also to bending forces. This way of loading also corresponds with the oval shape and thickened medial wall of the neck.

Erdheim-Chester disease. A case report.

A 63-year old man had a history of diabetes insipidus, arthralgias and myalgias, weight loss, relapsing fever and malaise. Increased uptake of Tc-99m was found predominantly in distal antebrachia, in distal femurs and in both trochanters and tibias on the bone scintigraphy. The chest radiograph showed reticulonodular pattern and the high resolution computed tomography (HRCT) scans revealed diffuse infiltrative lung disease with small multiple nodules and widening of interlobular septs. Videothoracoscopic lung biopsy and biopsy of tibial lesion were perfomed. The histopathologic examination proved non-Langerhans cell histiocytosis-Erdheim-Chester disease. Treatment with prednisone reduced the pain and fever and improved the vital capacity of the lungs while the changes in the lungs and bones remained unchanged.

[An unusual complication after tracheal resection for cicatricial stenosis]. / Neobvyklá komplikace po resekci prudusnice pro jizevnatou stenózu.

The authors describe the case of a patient where after segmental resection of the trachea on account of cicatricial postcannulation stenosis of the trachea osteomyelitis of the sternum developed with a tracheocutaneous fistula. The cause of the fistula was probably a small dehiscence not detected after operation at the site of the anastomosis with subsequent development of chronic inflammatory changes in the anterior mediastinum and sternum. The authors describe the diagnostic procedure and surgical solution of this uncommon complication.

[Surgical treatment of pulmonary aspergilloma and its complications]. / Chirurgická lécba plicního aspergilomu a její komplikace.

The authors present an account of their experience with the surgical treatment of 44 patients with pulmonary aspergilloma who were treated at the Clinic of Pneumology and Thoracic Surgery of the Third Medical Faculty Charles University in Prague during 1957-1999. The diagnosis of the disease before surgery was made in 39 patients (88.6%), in five patients it was established only after histological examination following resection of the lung. The presence of an aspergilloma was observed most frequently in a TB cavern (n = 30) and in bronchiectatic cavities (n = 9) with the most frequent localization in the upper pulmonary lobes (n = 38) and prevalence on the right side (n = 23). The most frequent symptom of the disease was haemoptysis (n = 39). All patients with the established diagnosis were treated before surgery by antimycotics. Treatment was however not successful and therefore the patients were indicated for surgery. The preoperative diagnosis of aspergilloma was based on X-ray or CT examination, serological examination (positive in 92.8%) and cultivation of sputum (positive in 58.9%). The most frequent surgical operation was lobectomy (n = 20), segmentectomy (n = 9), atypical resection (n = 8), pneumonectomy (n = 3); cavernostomy was performed in four patients. The most serious postoperative complication was a bronchopleural fistula with subsequent empyema (n = 2). During the postoperative period three patients died from respiratory failure associated with bronchopneumonia (6.8%). The authors recommend, based on their own experience, an active approach in patients with pulmonary aspergilloma and consider surgery as the main therapeutic method.

[Resection of the trachea in acquired cicatricial stenosis]. / Resekce trachey pro získanou jizevnatou stenózu.

The objective of the submitted paper is to draw attention to the possible occurrence of post-cannulation ciccatrial stenoses of the trachea after long-term artificial pulmonary ventilation and possibilities of a surgical solution. The optimal therapeutic method is resection of the stenotic portion of the trachea. The authors present an account on 22 patients where during the period from 1996-1998 a resection of the trachea was performed. Of basic importance for indication for resection of the trachea is bronchoscopic, X-ray (tomograms) and CT examination which assesses the diameter, site and length of the stenosis. The limiting factor is assessment of the length of the stenotic portion. In stenoses longer than 5-6 cm it is useful to consider insertion of a stent. The authors made resections of the trachea of a maximum length of 55 mm. As to postoperative complications restenoses were most frequent and were resolved by implantation of a Montgomery T-tube. Indications of patients for surgery on account of stenosis of the trachea calls for close interdisciplinary collaboration of the bronchologist, radiologist and thoracic surgeon. Due to the small number of patients operated with this complication it is useful to concentrate these patients in specialized departments.

Developmental defects and chromosomal aberrations in spontaneous abortions and stillbirths.

The authors analysed 1488 cases of spontaneous abortions and stillbirths in Bratislava. They focused on the course of human embryogenesis and the chromosomal constitution. A high mean frequency rate of both developmental defects (14.4%) and chromosomal aberrations (33.6%) was revealed and both were found to be in close relation with the length of gestation. The most severe developmental defects occurred mostly in early stages of human embryogenesis, i.e. in the 1st trimester of gestation.

[Implantation of the T-tube in patients with postintubation tracheal stenosis]. / Zkusenosti s implantací T-tubusu u nemocných s postkanylacní stenózou prudusnice.

The authors submit an account on their experience with implantation of a Montgomery T-tube in patients with postcannulation stenosis of the trachea. The T-tube was implanted in 10 patients during an 11-year period (1987-1997). In three patients the tube was inserted on account of restenosis which developed after resection of the trachea. In three patients resection treatment was not indicated because of the considerable length of the stenosis (60 mm), in two patients because of the finding of two stenoses at different levels of the trachea, in one patient because of a high stenosis of the trachea with penetrating granulation into the subglottic space and in one patient because of a medical contraindication. The diagnosis of stenosis and its character was based on tomograms of the trachea, bronchoscopy and possibly CT. The T-tube was implanted under general anaesthesia after revision of the tracheal stenosis and if necessary dilatation. The length of the tube always extended over the stenotic portion, in three patients it extended from the bifurcation to the stoma. The T-tube was very well tolerated by the patients and was renewed usually after one year. Only in one patient it proved possible to perform decannulation and close the stoma by a plastic operation using costal cartilage. In the remaining patients the cannula is gradually reduced in length and in some possible decannulation with closure of the stoma in future is assumed. The authors consider the use of a T-tube in some patients with tracheal stenosis a very good therapeutic method which should be used at present in indicated cases.

[Surgical treatment of bronchogenic carcinoma. Long-term results in 496 surgical patients]. / Soucasné moznosti resekcní lécby bronchogenního karcinomu. Dlouhodobé výsledky u 496 operovaných nemocných.

BACKGROUND: The operability of lung cancer and the period of survival after resection of the lungs in our country does not yet attain the standard recorded in some advanced countries. The objective of the present work is to analyze factors which influence the survival period after resection therapy of lung cancer. METHODS AND RESULTS: In 1985-90 in our department 496 patients were operated on account of lung cancer. This number comprised 31 patients subjected to explorative thoracototomy and three patients with pulmonary resection on account of a stage IIIb (pTNM) tumour who were excluded from the statistical analysis. The retrospective study proper analyzes the results of 462 patients (403 men and 59 women) operated in stages I, II and IIIa. Their mean age was 57 years (range 30-74 years, SD 7.5 years). The most frequent histological type was epidermoid carcinoma (68.8%), adenocarcinoma 18.2%, small-cell tumours 5.4% (25 patients). In 262 patients operated on account of lung cancer in stage I (pTNM) the probability of five-year survival was 49.2%, in patients in stage II 42.1%, in 158 patients in stage IIIa 20.9% (for all histological types combined). In 437 patients after resection of the lungs on account of non-small-cellular carcinoma the probability of five-year survival was as follows: stage I 50.0%, stage II 45.0%, stage IIIa 21.2%. CONCLUSIONS: The probability of five-year survival for the whole group of 462 patients in stages I, II and IIIa was 38.8%. The most important factor which influenced the probability of five-year survival was the stage of the disease. Neither age nor sex of the patients nor the histological type of the tumour had a statistically significant effect on the probability of five-year survival.

[Explorative thoracotomy in patients with bronchogenic carcinoma]. / Explorativní torakotomie u nemocných s bronchogenním karcinomem.

The authors analyse in a retrospective study a group of 31 patients with explorative thoracotomy, which was performed on account of inoperable bronchogenic carcinoma. The causes of inoperability were assessed and the period of survival after explorative thoracotomy was evaluated. From the total number of 496 patients indicated in 1985-1990 for surgery on account of bronchogenic carcinoma 465 pulmonary resections were made and 31 (6.25%) explorative thoracotomies. In all these patients the c TNM and p TNM classification was assessed. Disagreement in the evaluation of these parameters was found in particular in parameter T which was in agreement only in three instances. Conversely agreement was more frequent in parameter cN and pN (n = 18). The most frequent cause of inoperability was penetration of the tumour into the mediastinum (n = 25). Death within 30 days after surgery was not recorded in the group, three patients of 31 survived 5 years after exploration. Explorative thoracotomy did not exert a negative effect on the period of survival which corresponded to the given stage of the disease. Due to improving preoperative examination methods the number of explorative thoracotomies will probably decline in future, but at present it cannot be completely eliminated.