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O Luz

Publications and source records attributed to O Luz.

18 recordsLinked to original sources
PubMed2004

[Evaluation of different 16-row CT colonography protocols using a porcine model].

PURPOSE: To develop and to test an easily produced biological colon model with simulated polypoid lesions. Application of this phantom for the selection of an optimized scan protocol of 16-row CT colonography (CTC) for clinical use. METHODS AND MATERIAL: Six polypoid lesions (1 - 6 mm) were simulated with sutures on the inner face of a porcine colon segment (20 cm). After distending the colon segment with air, the phantom was placed in a water quench and CT scans were performed on a MDCT-scanner (Somatom Sensation 16, Siemens, Forchheim). At constant values for collimation (16x0.75 mm) and voltage (120 kV), 54 different combinations of mAs values (50, 75 and 100 mAs), pitch factors (1, 1.25 and 1.5) and slice thicknesses (0.75, 1.0, 1.5, 2.0, 3.0 and 5.0 mm) were tested systematically. The phantom was scanned in the longitudinal and transverse axis to simulate the different orientation of the colon in the abdomen. Axial slice images and virtual endoscopic views of all data sets were presented separately to 2 radiologists who independently determined number and size of detectable polyps. Dose exposure was measured with an Alderson phantom. RESULTS: The colon model offered a realistic imitation of a polyp-covered, human colon. The experimental set-up allowed a systematic evaluation of polyp detection related to lesion size, orientation of the colon and CTC parameters, with other influencing factors mostly excluded. Polyps were significantly better detected in the longitudinal than in the transverse orientation of the colon. For the detection of lesions of at least 3 mm, a low dose (50 mAs) 16-row CTC should be combined with a pitch of 1.5 and a maximum slice thickness of 3 mm. For the depiction of polyps smaller than 3 mm, slice thickness and pitch should amount to 1 mm and 1.0, respectively. Effective dose of this low dose protocol is 4.08 mSv. CONCLUSION: The porcine colon phantom represents a realistic and easily produced alternative to other colonography models. It allows a preselection of a CTC-protocol for subsequent clinical testings. If the high in vitro performance of the low-dose 16-row CTC-protocol is confirmed on a human collective, the use of 16-row technique would represent a big step for CTC toward a screening method.

Animals↗
PubMed2003

Assessment of peripheral arterial occlusive disease: comparison of multislice-CT angiography (MS-CTA) and intraarterial digital subtraction angiography (IA-DSA).

PURPOSE: The aim of the study was to assess the arterial vascular system of the lower extremities in patients with peripheral arterial occlusive disease using Multislice-CT angiography (MS-CTA) and to compare the results with the standard of reference, intraarterial digital subtraction angiography (IA-DSA). MATERIALS AND METHODS: MS-CTA and IA-DSA of the lower extremities were carried out on 23 patients with peripheral arterial occlusive disease (Fontain Stage IIb: 18, III: 3, IV: 2). MS-CTA comprised a 4 x 2.5 mm collimation, 15 mm table feed/rotation, 0.5 sec rotation time and 3 mm slice thickness (1.5 mm reconstruction increment). Delay time was determined by bolus tracking. 150 ml of contrast media were injected intravenously at a flow rate of 3 ml/sec. Maximum intensity projection (MIP) reformations were performed using a semi-automatic vessel tracking program. MS-CTA (axial and MIP-reformatted images) and IA-DSA were reviewed by two radiologists. The grade of vascular stenosis as well as occlusion were rated on a scale of 0 to 3 (0=0-50% stenosis, 1 = 51-75% stenosis, 2 = 76-99% stenosis, 3 = occlusion). RESULTS: For MS-CTA, the mean delay time was 30.2 s (23-40 s), mean scan time was 37.4 (33-42 s). Data analysis was based upon a total of 1136 vascular segments for both methods (568 each). A comparison of all the evaluated segments in both techniques revealed a MS-CTA / IA-DSA 86.3% match. Out of 442 segments proximal the trifurcation, 386 were correctly assessed in MS-CTA (87.3%) and distal the trifurcation, 101 out of 126 segments were rated correctly (80.2%). In MS-CTA, an overall confidence interval of 95% can be achieved in 83.2% to 89.0% for correctly rated stenosis grading. CONCLUSIONS: In patients with peripheral arterial occlusive disease, MS-CTA of the lower extremity is a promising minimal-invasive method for detection of relevant arterial stenoses. However, the technique was limited to routine diagnostic purposes due to severe calcifications and time consuming reconstruction procedures.

Aged↗
PubMed2002

Endovascular treatment of peripheral artery disease with expanded PTFE-covered nitinol stents: interim analysis from a prospective controlled study.

PURPOSE: Current covered peripheral stent designs have significant drawbacks in terms of stent delivery characteristics and flexibility. The aim of this study was to analyze the technical performance, safety and initial clinical efficacy of expanded polytetrafluoroethylene (PTFE)-covered nitinol stents for arteriosclerotic peripheral artery disease. METHODS: Eighty-two patients underwent implantation of PTFE-covered nitinol stents for iliac and/or femoral obstructions. The study was conducted prospectively in seven European centers and one Canadian center. Patients were controlled clinically and by duplex ultrasound follow-up. Data up to discharge were collected in 79 patients. Seventy-four patients have thus far received 1 month follow-up and 32 patients, 6 month follow-up examinations. RESULTS: The average lesion length measured 47 mm for the common and external iliac arteries and 50 mm for the femoral arteries. The mean severity of the stenoses was reduced from 94% to 4% in the iliac arteries and from 98% to 7% in the femoral arteries after stent placement and dilatation. One device deviation (inadvertent stent misplacement) and one puncture-related severe adverse event with formation of a pseudoaneurysm occurred. There were occlusions of the stent in five patients. No infections were noticed. CONCLUSION: The interim analysis of this trial using PTFE-covered nitinol stents indicates that a strategy using primary implantation of this stent type is technically feasible, has an acceptable safety profile and is effective from a short-term perspective.

Alloys↗
PubMed2002

[CT-colonography: current status and future directions in consideration of the technical evolution].

Computertomography and with it CT-colonography evolves technically and also possibilities of data processing proceed rapidly. The current status of CTC can be summarized as follows:The method represents a true alternative to barium enema if technical conditions are given.CTC can be performed with excellent results immediately following an incomplete colonoscopy. In pretherapeutic diagnosis of colorectal carcinoma, CTC can be combined with a staging CT of the abdomen. The recent technical advances with new 16 row technology in image quality and data acquisition - mainly concerning the spatial and temporal resolution - are very promising. Developments in postprocessing of CT data can also contribute to a higher efficiency of labor. Alternative preparation schemata can lead to a more comfortable bowel cleansing and stool labeling can even avoid this procedure, resulting both in an even improved compliance. Radiation exposure in low dose technique is comparable to a double contrast barium enema and can be still reduced by optimisation of scanning parameters.The aim of the following article is (1 to give an overview of the current status of patient preparation, image acquisition and data processing; (2) to review recent clinical trials and experimental studies and to show future directions of CTC with regard to the clinical development.

Colonic Polyps↗
PubMed2001

Peripheral artery occlusion: treatment with abciximab plus urokinase versus with urokinase alone--a randomized pilot trial (the PROMPT Study). Platelet Receptor Antibodies in Order to Manage Peripheral Artery Thrombosis.

PURPOSE: To evaluate the combination of a platelet glycoprotein IIb/IIIa complex receptor inhibitor and urokinase for treatment of recent (<or=6 weeks) arterial occlusion of the legs. MATERIALS AND METHODS: Seventy patients with lower extremity arterial occlusion of less than 6 weeks duration were randomly separated into two treatment groups: urokinase plus abciximab or urokinase plus placebo. Primary end points were the rate of major complications at 30 days after randomization and the rates of amputation-free survival and survival without open surgery or major amputation at follow-up of 90 days. Two readers unaware of the patients' treatment group assignments analyzed digital subtraction angiograms as they related to the study end points, with a final consensus reading. RESULTS: Thrombolysis relative to clot length was faster in the urokinase-plus-abciximab group (odds ratio, 0.52; 95% CI: 0.35, 0.76; P < .001). There were no procedure-related deaths or intracranial hemorrhages, but the rate of nonfatal major bleeding was higher with urokinase plus abciximab (four of 50 patients) than with urokinase alone (none of 20 patients; P = .32). At 90 days, amputation-free survival was 96% (48 of 50 patients) in the urokinase-plus-abciximab group compared with 80% (16 of 20 patients) in the urokinase alone group. The hazard ratio for the two Kaplan-Meier curves was 0.42 (95% CI: 0.16, 0.96; P = .04). CONCLUSION: In patients with lower extremity arterial occlusion who were undergoing urokinase thrombolysis, adjunctive abciximab treatment resulted in faster thrombus dissolution and improved amputation-free survival, despite an increase in major bleeding.

Abciximab↗
PubMed2000

[Pulsed spray lysis with reteplase in peripheral arterial occlusions--technique and initial results].

PURPOSE: Urokinase followed by rt-PA are the most frequently used drugs approved for thrombolysis in peripheral arteries in the USA and Europe. We wanted to test the safety and efficacy of low-dose reteplase administered by pulsed spray technique. MATERIALS AND METHODS: 10 patients with acute or subacute occlusion of a peripheral artery (n = 8) or graft (n = 2) were treated (history 8 +/- 17 days; occlusion length 4-60 cm, mean 23 cm). Reteplase was administered as an intra-arterial (i.a.) bolus (0.5 U/10 cm of occlusion length) followed by pulsed spray lysis (1 U/h for the first 2 h, then 0.5 U/h). The catheter was placed into the occlusion. In addition the patients received heparin (i.a.) and aspirin (oral). The site of puncture was closed with a percutaneous suturing system prior to discontinuation of heparin treatment. RESULTS: A total dose of 3.3 +/- 1.2 U reteplase was administered. The primary success rate was 7/10. Two distal embolizations and two bleeding complications were observed (one minor bleeding at the site of puncture and one rupture of the suture which had to be treated surgically). CONCLUSION: With regard to our limited data, low-dose i.a. reteplase seems to be safe and effective. Two bleeding complications were observed which both occurred at the site of puncture. Discontinuation of heparin treatment prior to sheath removal is recommended. Fibrinolysis with reteplase may be an alternative to urokinase or rt-PA.

Aged↗
PubMed1997

Plasma extravasation and neuropeptide release in human skin as measured by intradermal microdialysis.

Time course of plasma extravasation in neurogenic inflammation elicited by histamine iontophoresis and topical capsaicin application was measured in vivo by a modified intradermal microdialysis technique in humans. Single linear plasmapheresis fibers were inserted intracutaneously at the volar forearm and perfused with Ringer's solution (4 microl/min) with one microdialysis fiber located at the planned stimulation site and a second inside the axon reflex area. Protein concentration in the dialysate increased by 300% in the histamine wheal but no increase was found in the surrounding flare area. There was no protein extravasation in the skin treated with capsaicin nor in the surrounding flare region. Inside the histamine-induced flare reaction a significant increase of calcitonin gene related peptide (CGRP) was found, whereas the increase of substance P (SP) was not significant.

Adult↗
PubMed1992

Capillary versus arterial plasma catecholamines as markers for sympatho-adrenal activity in infants.

In this study, we investigated whether capillary plasma catecholamines can be used as a suitable substitute for arterial catecholamines. Analysis was done radioenzymatically. Catecholamine concentrations were not different in arterial and simultaneously collected "arterialized" (warmed foot) capillary plasma obtained by heel-prick from 18 neonatal intensive care patients as assessed by linear regression analysis (correlation coefficient: 0.966 for noradrenaline; 0.894 for adrenaline; p less than 0.05) and by a Wilcoxon test [noradrenaline: 2.13 (0.61-10.47) versus 2.41 (1.05-10.23); adrenaline: 0.75 (0.16-1.70) versus 0.72 (0.10-1.37) nmol/L, median (range)]. However, "arterialization" of capillary blood is important; when blood was obtained in nine neonates without warming their feet, capillary concentrations of noradrenaline were higher than arterial values (p less than 0.03) and those of adrenaline were not different from arterial values. Catecholamine concentrations in arterialized capillary plasma collected in healthy full-term infants at 1 h [n = 9; noradrenaline: 6.85 (3.09-8.88) nmol/L; adrenaline: 1.34 (0.86-2.85) nmol/L] and 5 d after birth [n = 27; noradrenaline: 1.58 (0.89-3.16) nmol/L; adrenaline: 0.59 (0.25-1.64) nmol/L] reflect the well-known fall (p less than 0.01) in catecholamine levels after delivery. With a highly sensitive analytical technique, catecholamine concentrations can reliably be assessed in minute samples (100-200 microL) of arterialized capillary blood, even when concentrations have dropped to low "resting" basal levels. Moreover, the capillary sampling procedure is simple and safe, can easily be applied to healthy infants, and does not have the practical and ethical limitations of arterial blood sampling.

Adrenal Glands↗
PubMed1987

[Identification of group B streptococcal infection by the latex test].

A commercial latex agglutination test (Wellcogen Strep B) has been prepared for testing body fluids. This test does not require a special equipment and is very easy to handle. Results are established within few minutes. We examined this method in unconcentrated urine specimens of 98 pre- and full term neonates suffering from RDS. In all 48 cultural proven cases of strep. B sepsis LAT was positive, the test was performed 2.5 h-19 h after onset of RDS. Four times we could not exclude false positive results definitively, but no false negative results were found.

Diagnosis, Differential↗
PubMed1987

[Early detection of mucoviscidosis patients using trypsin RIA in dried blood stains].

Trypsin radioimmunoassay in dried blood spots has proven as a simple and reliable method for early detection of CF. We tested this method in 6524 newborns. Two cases of CF were found, no false negative results occurred. However in this time usefulness of screening for cystic fibrosis remains in question; although better results in lung-function and weight-gain can be found by early onset physiotherapy and substitution of pancreatic enzymes a specific therapy is still missing.

Blood Stains↗
PubMed1987

[Severe course of osteopathy in Lowe's oculocerebrorenal syndrome].

A boy with oculo-cerebro-renal syndrome died at the age of 5 months after a rapid course of this disease with severe osteopathy resistant to therapy. Radiological findings and parameters of mineralisation metabolism will be shown. There are signs indicating both, a disturbed osteoid production due to the underlying disease and a diminished bone mineralisation because of the renal involvement.

Bone and Bones↗
PubMed1985

[Percutaneously implanted silastic catheters in the neonate].

In 21 infants requiring total parenteral nutrition 23 Silastic central venous catheters were placed by percutaneous insertion into the basilic vein. Weight of the infants was 1770 g (980-3540 g), age at time of insertion 1,6 days (1-16 d), gestational age 32 weeks (29-39) weeks. Catheters remained in place between 3 and 37 days, total 451 patient days. No problems as infection or thrombophlebitis or caval obstruction occurred.

Catheters, Indwelling↗
PubMed1985

[Development of premature children below a birth weight of 1,500 g].

5,928 newborn infants were admitted between the years 1974 and 81 to the University of Innsbruck, Department of Pediatrics. 418 (7%) of them were premature infants with a birthweight of less than 1,500 g. 21 (18%) of the premature infants with a birthweight below 1,000 g survived (21 of 117). Among those 21 surviving infants only 7 (33%) had an appropriate birthweight, 14 (67%) were too small for their gestational age. Survival in the weight range between 1,000-1,500 g was 71% (213 of 301). The percentage of dystrophic infants was 23% (49 of 213). The place of birth has a significant influence on the survival of these very small immature infants. 24% (n = 84) of patients delivered in the nearby Clinic of Obstetrics survived in contrast to only 3% (n = 33) of those born in peripheral hospitals. This is reemphasized by the evaluation of psychomotor development of surviving infants; of 14 patients with normal psychomotor milestones 13 were delivered at our obstetric department. 157 patients were regularly followed up during their first year of life. 43% can be considered normal by all parameters. 57% show some abnormalities in their development during the first years of life. During their second year of life only 13% showed psychomotor problems and this number decreased to 5% in the third year. All these children show varying degrees of hemi- or diplegia and/or seizure activities. A routine check up at 12 month of life seems important as all patients with permanent retardation can be correctly diagnosed at this age.(ABSTRACT TRUNCATED AT 250 WORDS)

Body Height↗
PubMed1985

[Unusual cutaneous emphysema in a newborn infant following bilateral pneumothorax].

We report a patient with subcutaneous emphysema after a bilateral pneumothorax of gigantic extent: Subcutaneous emphysema extended over the chest, neck, axilla and both arms. The scalp was severed from the galea by an enormous air-cushion. Theories about the pathogenetic mechanisms are discussed. Therapy consisted of treatment of the underlying condition e. g. thoracocentesis with pleural drainage and artificial ventilation. The subcutaneous emphysema resolved without further therapeutic measures; only the subgaleal air was removed by aspiration.

Emphysema↗
PubMed1984

[Pneumothorax as a cause of acute and recurrent neonatal hypoxia].

In 191 children suffering from RDS treated by mechanical ventilation or CPAP + PEEP according to the same protocol the incidence of pneumothorax was determined with 23% (44 infants). Mean birthweight and mean gestational age were lower in infants who developed pneumothorax. Pneumothorax occurred more frequently in children with bad pre- and perinatal history. Children who developed pneumothorax had received a lower fluid intake than those without. Incidence varied with severity of RDS and intensity of respiratory assistance. We tried to asses the duration and severity of hypoxia by means of transcutaneous pO2 measure and arterial blood gas analyses. As fast diagnosis and therapy helps to shorten the duration of hypoxia, we listened up the most frequent alternations of vital signs associated with pneumothorax. We found cyanosis, changes in heart rate and respiratory rate, arterial blood pressure and decrease of paO2. Hints to avoid a pneumothorax are given.

Humans↗
PubMed1984

[Follow-up study of children with hypoxia following pneumothorax].

A group of 23 children suffering from neonatal hypoxia (pO2 less than 50 mm Hg) due to pneumothorax was examined at an average age of 14 months. Evaluation at this early developmental stage was accomplished by combination of "Motoscopy", "Vojta's postural reactions" and the "Concept of provocation of normal behaviour under adverse conditions". Development of the group as a whole was found to be unexpectedly good: Two children with cerebral palsy, and seven with yet undefinable developmental course versus fourteen obviously normally developing children. Pneumothorax and drainage did not cause the frequent transient postural asymmetries in this group.

Age Factors↗