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Biomedical subjects

W Becker

Publications and source records attributed to W Becker.

At least 397 records · Page 22Linked to original sources
PubMed1988

Lid-eye coordination during vertical gaze changes in man and monkey.

1. To investigate the coordination between the upper lid and the eye during vertical gaze changes, the movements of the lid and the eye were measured by the electromagnetic search-coil technique in three humans and two monkeys. 2. In both man and monkey, there was a close correspondence between the metrics of the lid movement and those of the concomitant eye movement during vertical fixation, smooth pursuit, and saccades. 3. During steady fixation, the eye and lid assumed essentially equal average positions; however, in man the lid would often undergo small idiosyncratic movements of up to 5 degrees when the eye was completely stationary. 4. During sinusoidal smooth pursuit between 0.2 and 1.0 Hz, the gain and phase shift of eye and lid movements were remarkably similar. The smaller gain and larger phase lag for downward smooth pursuit eye movements was mirrored in a similar reduced gain and increased phase lag for downward lid movements. 5. The time course of vertical lid movements associated with saccades was generally a faithful replica of the time course of the concomitant saccade; the similarity was especially impressive when the details of the velocity profiles were compared. Consequently, lid movements associated with vertical eye saccades are called lid saccades. 6. On average, lid saccades start some 5 ms later than the concomitant eye saccades but reach peak velocity at about the same time as the eye saccade. Concurrent lid and eye saccades in the downward direction have similar amplitudes and velocities. Lid saccades in the upward direction are often smaller and slower than the concomitant eye saccades. The relation of peak velocity versus amplitude and of duration versus amplitude are similar for lid and eye saccades. 7. To investigate the neural signal responsible for lid saccades, isometric tension and EMG activity were recorded from the lids of the two authors. 8. The isometric tensions during upward lid saccades exceeded the tensions required to hold the lid in its final position.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1988

A longitudinal study comparing scaling, osseous surgery and modified Widman procedures. Results after one year.

The purpose of this study was to compare, longitudinally, the effectiveness of scaling and root planing, osseous surgery, and the modified Widman procedures. The study was carried out in a private practice setting. Sixteen adult patients with moderate to advanced adult periodontitis were treated with initial scaling and oral hygiene procedures. Posthygiene data were used for comparison of changes in probing depth, clinical attachment levels and gingival recession. The initial examination data were used to compare changes in plaque and gingival indices. Frequency distributions were used to compare changes that occurred at individual sites. At one year, plaque and gingival indices were significantly reduced when compared with the initial examination. At one year, shallow pockets (1-3 mm) were reduced when compared to posthygiene. Four- to six-millimeter pockets were significantly reduced by the three procedures. Osseous surgery and modified Widman had significantly greater pocket reduction when compared with scaling. For pockets greater than 7 mm, osseous surgery and the modified Widman had significantly greater reduction when compared with scaling. For pockets 1-3 mm at one year osseous surgery had significantly greater clinical attachment loss when compared with scaling. For 4-6 mm pockets at one year, the three procedures had slight gains in clinical attachment levels. The results were similar for pockets with greater than 7 mm. Interproximal soft tissue craters were measured for six postoperative weeks. Initially, the modified Widman had a higher percentage of soft tissue craters when compared with osseous surgery. At six weeks, however, there were no significant differences when the surgical procedures were compared. Recession was measured at each examination. Recession for 1-3 mm pockets at one year was greater for osseous surgery when compared with scaling and the modified Widman. Recession for 4-6 mm and greater than 7 pockets was greater for the surgical procedures than scaling. The results from this study indicate that with three-month maintenance recalls, both the modified Widman and osseous surgery are effective for pocket reduction, and each will produce a slight gain of clinical attachment over one year. Scaling was effective at maintaining attachment levels but was not as effective in reducing pocket depth.

Adult↗
PubMed1988

[Preventative vaccination against EHV (equine herpesvirus) abortion].

From 1981 until 1987 we investigated the more detailed circumstances regarding a prophylactic vaccination in altogether 37 stud farms with a history of virus abortion. In 23 cases, in which Prevaccinol and/or Resequin were used, it was found that the following of vaccination schedule and necessary immunization programmes respectively, had considerable imperfections. In seven cases prophylactic vaccinations were not carried out or corresponding questionnaires were not answered. The fact that in the present data no case of virus abortion was observed, when the mare was vaccinated according to the instructions within a regular vaccinated population, certainly speaks for the vaccination. Of course the inquiries made have also shown that in practice it is very difficult to meet all the requirements fixed in the instructions for immunization. But with regard to the general problems at control of herpes virus infections and at avoidance of any discrimination of the vaccination, these requirements may not be loosened. Those who are concerned must be aware of the fact that every variation of the vaccination instructions is linked to an increased risk of illness and that vaccination cannot substitute a sound management.

Abortion, Veterinary↗
PubMed1988

Hysterosalpingoscintigraphy: a simple and accurate method of evaluating fallopian tube patency.

A prospective study was designed to evaluate the efficacy of radionuclide hysterosalpingoscintigraphy using 99mTc-labelled human serum albumin macroaggregates in 17 patients (34 tubes). In normal females the macroaggregates migrate spontaneously through the female reproductive tract following application into the posterior vaginal fornix. They can be seen in the uterine fornix 20 min p.i. (range: 5-90 min) and as free pelvic activity 120 min p.i. (range 40-180 min). Free pelvic activity could also be demonstrated by culdocentesis. In infertile patients with failure of tubal patency images after 180 min offered no additional information. For the routine diagnosis camera images 5, 60 and 180 min p.i. are recommended. Using 5-10 MBq 99mTc the radiation exposure to the ovaries is about 1/9th of the exposure from a normal radiologic hysterosalpingogram. The reported data show results comparable with those of hysterosalpingography (HSG) in females with patent or with nonpermeable tubes, but in cases of high-pressure by patency by HSG the results of scintigraphy are superior to those of HSG. Moreover, this method provides new insights into sperm motility under various physiological and pathological conditions.

Adult↗
PubMed1988

New immunodiagnostic systems.

Two new systems for homogeneous plasma protein immunoassays, the Behring Nephelometer System and the Behring TurbiTimeSystem, as well as the Behring ELISA System for heterogeneous enzyme immunoassays are described.

Blood Proteins↗
PubMed1987

The 111In-granulocyte scan in prosthetic vascular graft infections: imaging technique and results.

Fourteen patients were examined between 3 weeks and 11 years after implantation of an aortobifemoral vascular graft with 111In labelled leukocytes isolated with discontinuous gradient centrifugation. The camera acquisition was performed with a three phase technique (acquisitions at 30 min, 4 h and 24 h p.i.). The presence and extent of a graft or perigraft infection including complicating fistulas could be correctly diagnosed in six of eight patients with surgically proven infections. Leukocyte uptake index was calculated as 1.77 +/- 0.4 (30 min p.i.) and 2.4 +/- 0.7 (24 h p.i.). All infections could be diagnosed by 30 min p.i., fistulas only could be seen 24 h p.i. In two of eight patients, false positive results were observed. These patients suffered from suspected perigraft hematomas and noninfected aortic graft aneurysms. Both had a negative 30 min scan and a slight uptake in the late scans comparable to bone marrow activity. Six patients with fever of unknown origin showed true negative scans. There were no false negative scans. We conclude that only the leukocyte scan can diagnose the presence and the extent, including fistulas, of vascular graft infections. The three phase technique is recommended to localize the blood pool in the 30 min scan and to diagnose complications 24 h p.i. In cases of a negative 30 min scan and positive 4 h and 24 h scans, false positive results should be suspected. All infections have a leukocyte uptake index higher than 1.2.

Aged↗
PubMed1987

[Meniscus imaging in MR tomography using surface coils. Anatomy, areas of degeneration, laceration formation].

High resolution MR imaging using surface coils and thin-section techniques provides specific information when evaluating meniscal diseases. Extension and localisation of meniscal tears can be demonstrated as well as meniscal attachment areas. Diagnosis of degenerative changes is possible. We examined 7 healthy volunteers and 58 patients with suspected knee injuries. This study was done to discuss the use of MRI in the evaluation of meniscal diseases.

Arthrography↗