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Biomedical subjects

B K Smith

Publications and source records attributed to B K Smith.

9 recordsLinked to original sources
PubMed1992

Human IL-1 receptor antagonist partially suppresses LPS fever but not plasma levels of IL-6 in Fischer rats.

A human recombinant interleukin-1 receptor antagonist (IL-1ra) recognizes the two known IL-1 receptors and blocks the binding and many biological effects of both IL-1 alpha and IL-1 beta. The effectiveness of IL-1ra in modifying the fever and plasma IL-6 responses elicited by lipopolysaccharide (LPS) in vivo was tested in Fischer 344 rats. Animals that received IL-1ra 0.5 mg/kg intraperitoneally followed 10 min later by 10 micrograms/kg of LPS displayed significantly lower mean fever responses 2-4 h after injection than rats that received vehicle and LPS (0.48 +/- 0.13 vs. 0.95 +/- 0.16 degrees C, P = 0.016). Plasma levels of IL-6 at 4 h after injection were not different in IL-1ra-treated rats compared with controls (407,725 vs. 729,169 U/ml). Based on our previous finding that preadministration of antiserum to IL-1 beta markedly suppressed plasma IL-6 after LPS, and recent evidence that molar excesses of IL-1ra blocked IL-1-induced circulating IL-6 levels, the possibility that IL-1 is responsible for the induction of bioactive IL-6 during inflammation cannot be ruled out. Similarly, the inability of the IL-1ra to completely suppress the febrile responses of rats to LPS in the present study may be dose related. Alternatively, the induction of bioactive IL-6 by IL-1 in the rat may be mediated primarily through some receptor other than the type I (e.g., the type II receptor).

Animals↗
PubMed1991

Management of the oral and maxillofacial surgery patient on anabolic steroids.

Recent Food and Drug Administration estimates indicate that the anabolic steroid market has reached the $100 million level. Although the news media report steroid-related deaths, there is little in the medical literature communicating the clinical implications concerning these drugs. Electrolyte disturbances, coagulopathies, hypertension, and dysrhythmias are a few of the potential side effects. The pharmacology and pathophysiology of anabolic steroids are presented with a discussion of the anesthetic and surgical concerns for the patient undergoing oral and maxillofacial surgery.

Anabolic Agents↗
PubMed1990

Hearing a mistuned harmonic in an otherwise periodic complex tone.

The ability of a listener to detect a mistuned harmonic in an otherwise periodic tone is representative of the capacity to segregate auditory entities on the basis of steady-state signal cues. By use of a task in which listeners matched the pitch of a mistuned harmonic, this ability has been studied, in order to find dependences on mistuned harmonic number, fundamental frequency, signal level, and signal duration. The results considerably augment the data previously obtained from discrimination experiments and from experiments in which listeners counted apparent sources. Although previous work has emphasized the role of spectral resolution in the segregation process, the present work suggests that neural synchrony is an important consideration; our data show that listeners lose the ability to segregate mistuned harmonics at high frequencies where synchronous neural firing vanishes. The functional form of this loss is insensitive to the spacing of the harmonics. The matching experiment also permits the measurement of the pitches of mistuned harmonics. The data exhibit shifts of a form that argues against models of pitch shifts that are based entirely upon partial masking.

Adult↗
PubMed1985

Use of helium-oxygen to examine the effect of cold acclimation on the summit metabolism of a marsupial, Dasyuroides byrnei.

To determine whether marsupial mammals increase their metabolic capabilities during cold acclimation, the metabolism of both warm and cold acclimated Dasyuroides byrnei was examined by exposure to cold in a helium-oxygen atmosphere. Mean values of heat production and conductance were significantly higher in a helium-oxygen atmosphere than in air. Body temperature did not change until metabolic capacity was exhausted. Both cold and warm acclimated groups could maintain a metabolic scope of 10-11 times the basal or standard level for this species. Such a metabolic scope is much higher than levels recorded for placental mammals. At very low ambient temperatures cold acclimated D. byrnei could sustain a high level of heat production longer than could warm acclimated animals. While there are some similarities between marsupial mammals and placental mammals in their responses to cold acclimation, an increase in maximum metabolism, as reported for placentals, does not seem to occur in marsupials.

Acclimatization↗
PubMed1975

Serum pyridoxal, folate, and vitamin B12 levels in institutionalized epileptics.

Serum pyridoxal, folate, and vitamin B12 concentrations were measured in 68 institutionalized patients with severe epilepsy. Twenty-five patients had a reduced level of pyridoxal and thirty-three a reduced level of folate. There was no instance of a low serum vitamin B12 although in three patients the levels were found to be abnormally high. Fifteen patients had both a low serum pyridoxal and a low serum folate but there was no significant correlation. All patients had a normal hemoglobin concentration and a normal mean corpuscular volume. There was no close relationship between reduced serum vitamin levels and single or groups of anticonvulsant agents, although the size of the groups was too small to permit a detailed study.

Adolescent↗