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Biomedical subjects

J Beier

Publications and source records attributed to J Beier.

At least 55 records · Page 3Linked to original sources

[Computer graphics methods for 3-dimensional imaging of intrapulmonary space-occupying lesions of CT and MRI images].

AIM: To improve the pre-operative planning of interventional procedures in thorax surgery different methods of computer-graphical visualization of intrapulmonary lesions and adjacent anatomical structures based on CT and MR data were realized and compared to each other. DESIGN: In 21 patients with intrapulmonary lesions the image data was segmented by interactive and automatic algorithms and different reconstruction techniques were applied (maximum intensity projection; color-encoded and transparent surfaces; volume rendering). Based on these three-dimensional reconstructions, different views from arbitrary perspectives (including simulated endoscopic images) were generated and animated film sequences of the 3D scene were displayed with 30 frames/second. RESULTS: For all patients under review, a high-quality presentation of the relevant structures was obtained by use of the applied computer-graphical techniques. Even combinations of different visualization methods in one image can be generated with the software we developed. CONCLUSIONS: The various methods for image segmentation allow a fast and comfortable processing even of large data sets. The calculated values of tumor surface and volume can be used for quantitative studies and therapy control. The planning of surgical and interventional procedures can be supported by the simultaneous visualization of the intrathoracic lesion and the surrounding structures.

Aged↗

Thrombospondin-related adhesive protein (TRAP) of Plasmodium falciparum: expression during sporozoite ontogeny and binding to human hepatocytes.

Plasmodium sporozoites collected from oocysts, haemocoel and salivary glands of the mosquito show profound differences in their biological properties such as motility, ability to induce protective immune response and infectivity for vertebrate host cells. Sporozoites from salivary glands are much more infectious than those from oocysts and haemocoel. Differential expression of proteins, such as the circumsporozoite (CS) protein and the thrombospondin-related adhesive protein (TRAP), implicated in sporozoite recognition and entry into hepatocytes may account for the development of infectivity during ontogeny. We have carried out a series of experiments to: (i) analyse the expression and localization of TRAP in P.falciparum sporozoites during development in the mosquito; and (ii) elucidate the biochemical and adhesive properties of recombinant TRAP. Our data indicate that TRAP is not expressed in oocysts, whereas variable amounts of CS protein are found in this parasite developmental stage. Hemocoel sporozoites display the distinct phenotypes TRAP- CS protein+ and TRAP+ CS protein+ at a frequency of 98.5 and 1.5% respectively. Salivary gland sporozoites are all TRAP+ CS protein+. We also provide experimental evidence showing that recombinant TRAP binds to the basolateral cell membrane of hepatocytes in the Disse's space and that sulfated glycoconjugates function as TRAP ligands on human hepatocytes.

Amino Acid Sequence↗

[The correction for motion and visualization of subtraction angiographic data from the spiral CT].

Conventional image subtraction of CT sequences is hampered by extended motion artifacts. In this paper a motion correction procedure for the subtraction of images from two time-separate CT investigations is introduced. Native images are obtained in the first CT sequence, and a contrast medium examination is imaged in the second. The aim of image subtraction is sole presentation of the contrast medium. In contrast to conventional digital subtraction angiography (DSA), CT angiography rules out the possibility of direct image subtraction due to occurrence of extended motion artifacts in the time-shifted images. Such shortcomings can now be corrected by means of a new registration method developed for determination of local displacement vectors between the two images. This motion pattern is used to compute a new synthetic mask of maximum congruence with the contrast medium image. The resulting three-dimensional data record is presented by means of a special-purpose hardware enabling fast rotations and cut planes. New diagnostic possibilities can be achieved such as the creation of views that are not obtainable with conventional modalities and the assessment of calcified vessels.

Angiography, Digital Subtraction↗

Determinants for hospitalization from an emergency mental health service.

There has been limited systematic study of determinants of acute psychiatric hospitalization of children and adolescents. This study reviewed the records of children and adolescents who received emergency mental health services in one New Jersey county during 6 months of 1990 (N = 226). Using a structured form to abstract data, information was obtained on demographics, precipitating problems, past mental health services, substance use, family problems, and disposition. While suicidal behavior was not a predictor of acute hospitalization, the interaction of assaultive and suicidal behavior was predictive. Other contributory factors identified in the multivariate analysis included: child's substance use, family member's substance use, and initial emergency screening site. Recognition of present utilization patterns will facilitate the development of intensive community-based options for those with acute mental health problems.

Adolescent↗

[Benign metastatic leiomyoma of the lung].

The authors report on the case of a woman of 41 years of age presenting with asymptomatic multiple circular foci in the lung that were primarily suspected of being malignomas. Diagnosis of benign metastasising leiomyomas was confirmed for bilateral multiple circular foci suspected of lung metastasising originating from an unknown tumour of the lung. This diagnosis was achieved by open biopsy. The seemingly contradictory diagnosis of a benign but metastasising tumour is characteristic of a rare disease pattern that, however, is well documented in the literature. The course of the disease is compared with the data given in the literature.

Adult↗

[Experiences with a modified nephrostomy instrument kit in ultrasound-guided kidney fistulization].

During a period of 24 months, ultrasound-guided percutaneous nephrostomies were performed in 51 patients in the Hospital at Köln-Merheim. The procedure was carried out with a modified nephrostomy instrument manufactured by Angiomed, Ettlingen, according to our own design. The procedure was successful in 49 patients. In one case it had to be abandoned because of lack of patient co-operation. In one patient a pyonephrosis was found and the patient was treated surgically.

Humans↗

Hemodynamic response to LBNP following 2 hours HDT (-6 degrees).

Central hemodynamics have been determined during stepwise decreasing LBP in head-down tilt (HDT) of -6 degrees. Measurements were performed on eight healthy volunteers using right heart catheterization. During LBNP, pressures in the right atrium, pulmonary artery, and pulmonary capillary (preload) decreased in parallel with the increase of negative pressure applied to the lower part of the body. Similarly, stroke volume and cardiac output decreased with increasing negative pressure. Heart rate moderately increased (30%) as well as total peripheral resistance. The left ventricular function curve was shifted downward and to the left during LBNP indicating hypovolemia with no evidence of decreased contractility. Cardiac dimensions determined by echocardiography changed in a similar way as those obtained by invasive measurements. There was a very close correlation between stroke volume determined by thermodilution and by echocardiography. Plasma norepinephrine and dopamine tended to increase at the end of LBNP. Echocardiography proved a useful and reliable approach to hemodynamic measurement during LBNP and is recommended for analysis of hemodynamic parameters during zero G and Gz simulation.

Adult↗

Central hemodynamics during zero gravity simulated by head-down bedrest.

Central hemodynamics during head-down tilt of -6 degrees lasting for 2 h were studied using catheterization of the pulmonary artery. M-mode echocardiography was performed simultaneously. Significant increases occurred for pressures in the right atrium, pulmonary artery in pulmonary wedge position, and for pulmonary vascular resistance. Cardiac and stroke volume index, heart rate, mean arterial pressure, and total systemic resistance remained constant throughout the exposure time. Constancy was also observed for echocardiographic measures of cardiac dimensions. It is concluded that head-down tilt leads to an increase of preload without any evidence of disturbed left ventricular function. No distinct time course of hemodynamic variables could be seen. Echocardiography proved a useful method to study cardiovascular adaptations during head-down tilting.

Adaptation, Physiological↗

[Functional late results following peripheral replantation].

To obtain comparable ratings of late results after replantations a plan of examination is presented, including sensibility, function of tendons, degree of decrease in total hand function, integration of the replanted finger into hand function, subjective judgement of the result by the injured person, and persistent pain. Examination of 84 finger replantations showed the following results: 20% very good, 45% good, 27% satisfactory, and 10% poor.

Amputation, Traumatic↗

Avian malaria in African black-footed penguins.

Ten captive-reared African black-footed penguins (Spheniscus demersus) from a large outdoor colony were monitored for avian malaria, using several diagnostic tests. One treatment regimen was evaluated. Thin smear blood evaluation enabled detection of seven parasitemias involving Plasmodium relictum and Plasmodium elongatum in the penguins. Leukocytosis (relative lymphocytosis) was characteristic of infected birds. Parasitemia was detected as early as 21 days prior to onset of clinical signs (depression, anorexia, regurgitation, pale mucous membranes, and respiratory distress). The single bird that died had clinical signs only a few hours prior to its death. Treatment consisted of 0.03 mg of primaquine phosphate base/kg body weight, administered orally once daily for 3 days. Oral chloroquine phosphate therapy, given simultaneously, was administered in an initial loading dose of 10 mg of chloroquine phosphate base/kg body weight, followed by doses of 5 mg/kg at 6, 18 and 24 hours after the initial chloroquine dose. This treatment regimen prevented mortality and cleared parasites from the blood. Recurrences of malaria occurred in two birds that had received this treatment.

Animals↗

[Comparison of two point discrimination on the thumb and the big toe].

The functional value of operations for the replacement of thumbs by autotransplantation of the great toe depends on the recovery of sensibility. The two-point-discrimination of 107 thumbs compared to 121 great toes in persons aged between 10 and 70 years was examined. The thumb had age-independent mean value of 4,5 mm while that of the great toe decreased from 9,1 to 16,0 mm.

Adolescent↗

Relative efficacy of the proposed Space Shuttle antimotion sickness medications.

Space motion sickness has been estimated as affecting between 1/3 and 1/2 of all space flight participants. NASA has at the moment proposed a combination of promethazine and ephedrine (P/E) and one of scopolamine and dextroamphetamine (S/D), both given orally, as well as a transdermally applied scopolamine (TAS), as preventive and ameliorative measures. The reported double-blind study, tests the early phase actions and efficacy of the transdermal scopolamine (Transderm (TM)-V of ALZA Corporation) and compares these in detail to the oral medications. Motion sickness resistance was tested by standardized head movements while accelerating at 0.2 degree/sec2 to a maximum rotation of 240 degrees/sec, with an intermediate plateau of 10 min at 180 degrees/sec. To permit weighting motion sickness protection against other system influences, cardiovascular, psychological (subjective and objective), and visual parameter changes were documented for the three therapeutic modes. The relative impact of the various modalities on operational and experimental components of space missions is discussed. A comparison to intramuscularly administered promethazine (a backup therapeutic mode suggested for Space Shuttle use) is also included.

Administration, Cutaneous↗

Newly diagnosed chronic obstructive pulmonary disease. Clinical features and distribution of the novel stages of the Global Initiative for Obstructive Lung Disease.

BACKGROUND: The new guidelines of the Global Initiative for Obstructive Lung Disease (GOLD) propose a novel staging system for COPD. This study describes the frequency distribution of GOLD stages in newly diagnosed COPD patients in a large city pulmonary practice. METHODS: All patients newly admitted between 1995 and 1996 were analyzed retrospectively. Incident COPD cases were classified according to GOLD criteria. RESULTS: Among 1,434 patients, 210 were diagnosed with chronic obstructive pulmonary disease (COPD) (60% males, age 55 years, range 20-82 years). 67.5% of the patients were current smokers, 27% ex-smokers, and 5.5% nonsmokers. Based on GOLD criteria, 37% had stage 0, 5% stage I, 46% stage II, and 12% stage III COPD. Symptoms leading patients to seek medical advice were cough (84%), exertional dyspnea (70%), and sputum (45%), with a median symptom duration of 12 months (range 1-240 months). Compared with patients with GOLD stages 0-1, those with stages 2-3 were older (60 vs. 47 years, p < 0.001), heavier smokers (40 vs. 20 pack-years, p < 0.001), had a longer duration of symptoms (24 vs. 6 months, p < 0.001), and elevated IgE (stage 3 only, p < 0.04 vs. stages 0-2). Interestingly, stage 0 COPD patients did not have 'normal' spirometry, as indicated by significantly lower FEV(1) (% predicted) and FEF(25-75) (% predicted), compared with age-matched nonsmoking controls (93.1 +/- 1.8 vs. 99 +/- 1.6, p = 0.004; and 76.2 +/- 2.8 vs. 91.2 +/- 2.9, p = 0.0003, respectively). CONCLUSIONS: The majority of COPD patients seek medical advice at advanced disease stages, and smoke actively despite severe symptoms and functional impairment. However, nearly every second patient presents at stages 0-1, thus opening a window for therapeutic or behavioral intervention. GOLD guidelines are a useful basis to reinforce screening programs aimed at early detection and prevention of progressive COPD in individuals at risk and smoking cessation.

Adult↗