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W Becker

Publications and source records attributed to W Becker.

At least 433 records · Page 24Linked to original sources
PubMed1986

Three-phase white blood cell scan: diagnostic validity in abdominal inflammatory diseases.

Indium-111-oxine saline-labeled "mixed" leukocyte (n = 16) and "pure" granulocyte (n = 66) scans were prospectively performed as "three-phase" white blood cell (WBC) scans (imaging: 30 min, 4 hr, and 24 hr after reinjection of the cells) in 82 patients suspected of having abdominal or retroperitoneal abscesses or inflammatory lesions. Inflammation was verified histologically, endoscopically, radiologically or by autopsy in 51 and excluded in 31 patients. Sensitivity, specificity, and diagnostic accuracy of the 30-min scan (90%, 56%, 72%) were statistically significantly lower than the 4-hr scan (96%, 97%, 98%). Of the 24-hr scan sensitivity, specificity, and diagnostic accuracy were only 84%, 98%, and 89% because many patients with chronic inflammatory bowel diseases had excreted a portion of intestinal 111In activity by 24 hr. The overall sensitivity, specificity, and accuracy of the "three-phase" WBC scan were 98%, 97%, and 98%, respectively. Only one female patient showed a false-positive scan with granulocyte uptake in an ulcerating adenocarcinoma of the colon. The 4-hr scan or the three-phase study are recommended because of their high sensitivity, specificity, and excellent diagnostic accuracy (98%). The 30-min scan is less specific (56%); the 24-hr scan less sensitive (84%). The three-phase study additionally allows the differentiation between inflammatory bowel diseases and abscesses because it allows observation of granulocyte kinetics for 24 hr.

Abdomen↗
PubMed1986

[New approaches to electronic data processing in clinical evaluation of coagulation diagnosis].

The present paper describes several possibilities of electronic data processing (EDP) in clinical evaluation of new diagnostic reagents for coagulation. In order to evaluate two novel assays for determination of prothrombin time (PT) new statistical and graphical methods were developed and tested for their practicability. These methods are especially useful for establishing reference curves, for checking the characteristics of new PT reagents, for determining the "International Sensitivity Index" of each lot of reagents and of the specific therapeutic range for oral anticoagulation as well as for testing the comparability with other PT reagents. The results show that the statistical and graphical methods have proved their usefulness for clinical evaluation of new PT methods and that there might be further applications for such methods in comparison tests of similar coagulation assays.

Blood Coagulation Tests↗
PubMed1986

Immunoscintigraphy in medullary thyroid cancer using an 123I- or 111In-labelled monoclonal anti-CEA antibody fragment.

The monoclonal anti-CEA F(ab')2 fragment MAb BW 431/31, labelled with 123I or 111In, was used for immunoscintigraphy (IS) in 9 patients with medullary cancer of the thyroid (CCC). The results of 11 studies lead to the following conclusions: When using radioiodine as a label for MAb in IS, potassium iodide is absolutely necessary to block the thyroid which is of special importance in patients with thyroid cancer; Preinjection of "cold" MAb reduces the relatively high unspecific uptake (especially in bone marrow) of MAb BW 431/31, which is of special importance for the antibody labelled with 111In; IS with MAb BW 413/31 in patients with CCC and elevated serum CEA is positive only in cases with large secondaries; and In patients with CCC and several manifestations of secondaries, only a single (large) metastasis may be apparent.

Antibodies, Monoclonal↗
PubMed1985

Canal-neck interaction in vestibular neurons of the cat's cerebral cortex.

Interaction of semicircular canal and neck proprioceptive inputs was studied in the cerebral cortex of awake, intact cats. Neuronal responses were recorded extracellularly in the anterior suprasylvian gyrus of the left hemisphere. Stimulations consisted of horizontal rotations in the dark applied as sinusoids or position ramps. There were three stimulus conditions: (1) Pure canal stimulation; rotation of whole body. (2) Pure neck stimulation; rotation of trunk about stationary head. (3) Canal-neck interaction; rotation of head about stationary trunk. We recorded 105 neurons with either Type I or Type II canal response. These showed often pronounced non-linearities such as a clear firing increase upon rotation in the "on-direction" and hardly any decrease in the opposite direction. The responses reflected mostly angular velocity, but angular position signals were also obtained. In 79 neurons, either Type I or Type II neck responses were obtained. They coded either angular velocity, velocity plus position, or position. Canal-neck convergence was found in 67 of 88 neurons tested. In the majority of neurons, interaction was "antagonistic" in the sense that the canal and neck responses tended to cancel each other during rotation of the head about the stationary trunk. These neurons could signal trunk rotation in space rather than head in space or head relative to trunk. Most of the remaining neurons showed a "synergistic" interaction such that the response upon head rotation was enhanced as compared to whole body or trunk rotation. These neurons might be involved in the dual task of monitoring head rotation in space and relative to trunk. Interaction was compatible with linear summation of canal and neck inputs in 70% of the neurons. In part of these, however, the assumption had to be made that the interaction had taken place already at some stage prior to the cortical neurons investigated. The response characteristics of cortical canal neurons are discussed in comparison to vestibular nuclear neurons. Furthermore, parallels are drawn between the observed canal-neck interactions in the cortical neurons and (i) interactions of canal and neck dependent postural reflexes in the decerebrate cat, and (ii) interactions of canal and neck induced turning sensations in man.

Animals↗
PubMed1985

Prediction in the oculomotor system: smooth pursuit during transient disappearance of a visual target.

Eye movements were recorded in human subjects who tracked a target spot which moved horizontally at constant speeds. At random times during its trajectory, the target disappeared for variable periods of time and the subjects attempted to continue tracking the invisible target. The smooth pursuit component of their eye movements was isolated and averaged. About 190 ms after the target disappeared, the smooth pursuit velocity began to decelerate rapidly. The time course of this deceleration was similar to that in response to a visible target whose velocity decreased suddenly. After a deceleration lasting about 280 ms, the velocity stabilized at a new, reduced level which we call the residual velocity. The residual velocity remained more or less constant or declined only slowly even when the target remained invisible for 4 s. When the same target velocity was used in all trials of an experiment, the subjects' residual velocity amounted to 60% of their normal pursuit velocity. When the velocity was varied randomly from trial to trial, the residual velocity was smaller; for target velocities of 5, 10, and 20 deg/s it reached 55, 47, and 39% respectively. The subjects needed to see targets of unforeseeable velocity for no more than 300 ms in order to develop a residual velocity that was characteristic of the given target velocity. When a target of unknown velocity disappeared at the very moment the subject expected it to start, a smooth movement developed nonetheless and reached within 300 ms a peak velocity of 5 deg/s which was independent of the actual target velocity and reflected a "default" value for the pursuit system. Thereafter the eyes decelerated briefly and then continued with a constant or slightly decreasing velocity of 2-4 deg/s until the target reappeared. Even when the subjects saw no moving target during an experiment, they could produce a smooth movement in the dark and could grade its velocity as a function of that of an imagined target. We suggest that the residual velocity reflects a first order prediction of target movement which is attenuated by a variable gain element. When subjects are pursuing a visible target, the gain of this element is close to unity. When the target disappears but continued tracking is attempted, the gain is reduced to a value between 0.4 and 0.6.

Adult↗
PubMed1985

Autologous 111In-oxine-labeled granulocytes in Yersinia infections.

Autologous 111In-oxine-labeled granulocytes have proved to be valuable for the localization of inflammatory bowel diseases, especially Crohn's disease and ulcerative colitis. Other rare inflammatory bowel diseases also yield positive 111In scans. One case of Yersinia infection of the terminal ileum (Yersinia enterocolitica) showing an accumulation of 111In-oxine-labeled granulocytes 0.5, 4, and 24 h after the reinjection of the labeled cells is described. The 4-day fecal excretion of 111In-oxine granulocytes showed a slight inflammatory activity of the terminal ileum. One negative scan is reported in a cotrimoxazole-treated patient with Yersinia infection.

Female↗
PubMed1985

[Value of preoperative nuclear medicine diagnosis in hyperthyroidism and thyroid cancer].

The optimal diagnostic procedure before surgery in thyrotoxicosis and thyroid malignancies is a combination of scintigraphy, sonography and fine-needle-aspiration biopsy. In diffuse toxic goiters the differentiation of immunogenic and non immunogenic thyrotoxicosis is predominant. In toxic nodular goiters the sonographic localisation in relation to the thyroid capsule is necessary to prevent recurrent autonomies. Malignomas should be subclassified (fine-needle-aspiration biopsy, calcitonin) to differentiate between carcinomas with necessary aggressive or conservative surgical treatment. After thyroidectomy in differentiated carcinomas a high I-131-uptake requires once more surgical resection to decrease radiation exposure during I-131-therapy.

Adenocarcinoma↗
PubMed1985

Measuring eye movements with a search coil: non-linear filter allows simultaneous recording of horizontal and vertical eye position by means of the phase modulation method.

Measuring eye position from the phase angle of the signal induced by a rotating magnetic field in a search coil presents a number of advantages. So far, however, existing schemes using this principle either record eye position in one dimension only or require two search coils. We describe here a simple analog circuit which singles out a signal of given frequency from a frequency composite without changing the signal's phase. This makes it feasible to measure horizontal and vertical eye position with a single search coil by using two orthogonal rotating fields of different frequency.

Electronics↗