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Biomedical subjects

B Walker

Publications and source records attributed to B Walker.

At least 289 records · Page 16Linked to original sources
PubMed1977

Reliable in vivo model for latent herpes simplex virus reactivation with peripheral virus shedding.

A long-sought laboratory model, a reliable system for in vivo reactivization of latent herpes simplex infection with peripheral shedding of active virus, is present. Results demonstrate that surgical stimulation of latently infected rabbit trigeminal ganglia induces peripheral release of infectious herpes simplex virus. Virus could be cultured from the tear film in 83% of the stimulated animals' eyes within 48 h.

Animals↗
PubMed1977

The preventability of "bloody taps" in second trimester amniocentesis by ultrasound scanning.

In 856 patients over a 6-year period, amniocentesis was performed in the midtrimester for prenatal genetic counseling. The use of ultrasound scanning of the gravid uterus prior to the procedure reduced the incidence of bloody taps threefold and the withdrawal of grossly bloody amniotic fluid by fourfold. The best results (7.6% overall and 2.0% grossly bloody taps) were obtained when the procedure was performed by an operator not only experienced and adept at intrauterine manipulation but who had training and experience in ultrasonography as well. These results contrast favorably with that of operators utilizing but not trained in ultrasound scanning (36% overall, 8% grossly bloody taps) and of those who had the uterus "mapped out" by a sonographist but performed the amniocentesis later in their offices (18% overall, 12.1% grossly bloody taps). Other advantages of prior sonography are also discussed.

Amniocentesis↗
PubMed1976

Renal failure, hemodialysis, and nafcillin kinetics.

Nafcillin (N) pharmacokinetics was studied in 27 subjectswith and without renal failure (RF) (determined by endogenous creatinine clearance, Ccr). Elimination rate constants (K) were calculated from serial serum levels of N measured from 2 to 12 hr after a single 500-mg intramuscular injection. Only 4 of 9 hemodialysis patients had measurable levels of N at 24 hr. The K values for the groups with normal renal function,moderate RF, severe RF, and on hemodialysis were 0.477 hr(-1), 0.432 hr (1), 0.369 hr(-1), and 0.306 hr (-1), respectively...

Adult↗
PubMed1976

Heterogeneity of the alpha subunit of tubulin and the variability of tubulin within a single organism.

When tubulins obtained from particular microtubules of the sea urchin (ciliary doublet A tubules, flagellar doublet microtubules, and mitotic microtubules) are analyzed by electrophoresis in a polyacrylamide gel system containing sodium dodecyl sulfate and urea, heterogeneity of the alpha subunit, and differences between the tubulins are revealed. The alpha subunit of tubulin from mitotic apparatus and from A microtubules of ciliary doublets is resolved into two bands, while the alpha subunit of flagellar doublet tubulin gives a single band. The mitotic and ciliary tubulins differ in the mobilities of their two alpha species, or in the relative amounts present, or both. The existence of differences between the tubulins has been confirmed by a preliminary analysis of their cyanogen bromide peptides.

Animals↗
PubMed1976

Nursing care in a combined adolescent medical-psychiatric unit.

In spite of the problems we have encountered in combining adolescent medical and psychiatric patients, we have found this to be a workable model. In summary, several areas are important in making this model functional: staff interest in both medical and psychiatric patients, in-service programs particularly in psychiatry, and open communication between health care givers. Certainly one of the most positive aspects of this unit is that it provides an environment which allows for easier adjustment to the community after hospitalization. Avoidance of such terms as "mental hospital," "crazy person" is less traumatic to the adolescent patient and his family.

Adolescent↗
PubMed1975

Responses of muscle spindles in a tortoise.

Responses were recorded from muscle spindles in the extensor digitorum longus muscle of the freshwater tortoise Chelodina longicollis. Most spindles showed no resting discharge unless the muscle was stretched up to a millimetre beyond the minimum body length. The firing rate then increased by 2-5 imp./sec/mm extension. All spindles were relatively insensitive to the rate of change of muscle length. The dynamic index was small and increased in direct proportion to the rate of stretch. Stimulation of selected filaments of the nerve produced a response from the spindle that was attributed to intrafusal contraction. A comparison of the response of the spindle to muscle stretch with the response during simultaneous stretch and stimulation of a motor filament revealed two distinct types of behaviour. In the first, a dynamic effect, motor stimulation greatly increased the response of the spindle to the velocity component of stretch. Other filaments had a static action: an increase in firing of the spindle with the muscle at constant length, but little change in the response to the velocity component of stretch. Stimulation of up to 7 different filaments produced an effect on a spindle. When the motor effects for a given spindle could be clearly characterised, they were all static or all dynamic. Both static and dynamic effects on the one spindle were seen only rarely.

Action Potentials↗