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Biomedical subjects

H Davis

Publications and source records attributed to H Davis.

At least 181 records · Page 10Linked to original sources
PubMed1982

Symptoms of TMJ dysfunction as related to stress measured by the social readjustment rating scale.

The data supported both research hypotheses. Patients with TMJ pain syndrome scored higher (p = .009) than the control subjects o the SRRS. As the number of symptoms increased, there was a tendency for scores on the SRRS to increase for all subjects (r = 0.58, p less than or equal to .05). The SRRS may be useful in evaluation and treatment planning of patients with these symptoms. Further research utilizing a larger sample size is necessary to determine the consistency of rating scores of patients versus nonpatients. Continued research is needed involving TMJ dysfunction to improve the multidisciplinary approach to and treatment of patients with problems in this area.

Disease Susceptibility↗
PubMed1982

Auditory brainstem responses in preterm neonates: maturation and follow-up.

Seventy-five neonatal intensive care unit patients with given auditory brainstem response screening tests at 40 db and 70 db above the normal adult hearing threshold. The presence of wave V, the criterion for pass, was strongly related to postconceptual age: It appeared at 70 db in 50% of the infants tested at 32 weeks' PCA and at 40 db in 50% of the infants tested at 40 weeks' PCA. Forty-four infants failed the last test before NICU discharge (15 at 70 db and 29 at 40 db), but most infants were discharged at a PCA of less than 40 weeks. No significant correlation appeared between ABR test failure and intraventricular hemorrhage, hyaline membrane disease, perinatal asphyxia, hyperbilirubinemia, or aminoglycoside therapy. Follow-up information was obtained in 23 of the 36 "failing" infants who survived (8 died). This consisted of definitive hearing tests in ten patients and historical information supporting normal auditory function in 13 patients. One case of severe hearing loss was confirmed. Thus, most failures of the ABR screen apparently resulted from immaturity. These data raise doubts regarding the effectiveness of ABR screening in the NICU.

Age Factors↗
PubMed1982

TMJ symptoms and referred pain patterns.

The purpose of this study was to determine the relationship between TMJ symptoms, (muscle tenderness, joint noise, deviant jaw opening and closing patterns, and limited jaw opening), and a history of referred pain patterns (earaches, headaches, neck pain, and sinus problems). A questionnaire was completed by 100 subjects regarding histories of the previously mentioned problems. The researcher then examined the subject's TMJs, and their symptoms were recorded as being present or absent. The following relationships were found to be significant: Headaches and lateral pterygoid muscle tenderness, Earache and medial pterygoid muscle tenderness, Neck pain and one or more tender muscles, Sinus problems and one or more tender muscles, Sinus problems and temporal muscle tenderness, Sinus problems and medial pterygoid muscle tenderness. However, r values for the above relationships were between 0.22 and 0.3 indicating that the relationships were not strong. It appears that some normal patients already have patterns of masticatory muscle tenderness and associated referred pain patterns prior to seeking treatment for acute TMJ symptoms.

Adult↗
PubMed1982

Predictability, control, and the pituitary-adrenal response in rats.

Five experiments were performed to compare to effects of signaled and unsignaled shock on the pituitary-adrenal response of rats. In Experimental 1, exposure to the two procedures yielded no difference in plasma corticosterone levels. In Experiment 2, the addition of a food-reinforced lever-pressing baseline produced conditioned suppression in the signaled condition but bo group difference in steroid values. In Experiment 3, in order to guard against steroid elevations produced by exposure to shock per se, blood samples were obtained during brief test sessions prior to the occurrence of shock. The procedure resulted in a significant elevation in the steroid levels of the signaled shock group. In Experiment 4, a within-subjects sampling procedure revealed that disparate group steroid values obtained earlier in the session had converged by the end of the test session. The final experiment replicated the original failure to obtain a steroid difference due to predictability in the absence of a behavioral baseline, despite the fact that blood samples were obtained by using the early "probe" sampling procedure. Collectively, these results suggest that (a) the effects of predictability are largely seen in the temporal pattern of steroid elevation and not in their terminal values, (b) the effects of predictability on steroids are modulated by the availability of control, and (c) control is not confined to the stimulus that is being predicted.

Animals↗
PubMed1981

Purification and characterization of a uracil-DNA glycosylase from the yeast. Saccharomyces cerevisiae.

An activity which releases free uracil from bacteriophage PBS1 DNA has been purified over 10,000 fold from extracts of Saccharomyces cerevisiae. The enzyme is active on both native and denatured PBS1 DNA and is active in the absence of divalent cation, and in the presence of 1 mM EDTA. The enzyme has a negative molecular weight of 27,800 as estimated by glycerol gradient centrifugation and gel filtration. Enzyme activity has been recovered after denaturation in SDS and electrophoresis in an SDS polyacrylamide gel. This analysis suggests that the enzyme consists of a single polypeptide chain of about 27,000 daltons. Normal levels of uracil-DNA glycosylase activity were found in partially purified extracts of the nitrous-acid sensitive rad18-2 mutant of yeast.

DNA Glycosylases↗
PubMed1981

Rheumatoid scleritis.

A 59-year-old black female with rheumatoid arthritis developed diffuse anterior scleritis with orbital and adnexal involvement. Computerized axial tomograhy (CAT) demonstrated the location and extent of the lesion. Biopsy of subconjunctival tissue revealed a rheumatoid nodule, characterized by granulomatous inflammation and fibrinoid necrosis. The patient improved rapidly on large doses of systemic corticosteroids. The relationship of scleritis to rheumatoid arthritis is discussed. The histopathologic features of rheumatoid scleritis, its apppearance on the CAT scan, and the management of this disease are also presented.

Arthritis, Rheumatoid↗
PubMed1981

The second filter is real, but how does it work?

The following speculative suggestions are offered informally concerning the "second filter" in the cochlea. Increased sensitivity is an advantage as important as increased sharpness of tuning. These two features and the "cochlea echo" strongly suggest a resonant system with high Q, which would also explain the prolonged latency near threshold of the action potential of the auditory nerve. The viscous damping of a mechanical resonator in the organ of Corti might be overcome by positive feedback. The seond filter is mechanically fragile and is vulnerable to anoxia. The source of the energy for positive feedback might be the cochlear microphonic of the outer hair cells. A possible transducer is hyaluronic acid located between the cilia and known to have piezoelectric properties.

Action Potentials↗
PubMed1981

Posterior packs and the nasopulmonary reflex.

Increased mortality and arterial hypoxemia have long been associated with posterior nasal packs placed for control of severe epistaxis. Several authors have postulated a nasopulmonary reflex to partially explain this clinically observed phenomenon. In ten young, healthy subjects, using a multiparameter pulmonary evaluation, posterior nasal packs were placed and no significant changes were observed in lung volumes, flow and alveolar gas exchange, especially oxygenation. These findings suggest that aspiration, sedation, and degeneration of pulmonary function with age, not a nasopulmonary reflex, have not been adequately emphasized in previously performed studies.

Adult↗
PubMed1980

Prolonged mechanically assisted ventilation. An analysis of outcome and charges.

Mechanically assisted ventilation is frequently used, but there are little data regarding cost and long-term outcome. Therefore, all patients who required mechanical ventilation for 48 hours or more were studied, their hospitalization charges analyzed, and the survivors observed for two years after discharge. The mean charge for the hospitalization was $12,300, compared with $1,600 for all other hospitalized patients. Although the overall mortality at discharge was 56%, the patients with pulmonary disease had the lowest mortality (29%) with the lowest cost at time of discharge. The mortality for the postoperative and miscellaneous medical group of patients demonstrated no significant increase during the period following discharge, unlike the cardiac and pulmonary groups, whose mortality increased each year of follow-up. Hospitalization for these patients was eight times as costly as for all other hospitalized patients during the same 12 months, with a two-year mortality of 72%.

Aged↗
PubMed1980

Auditory function in newborn intensive care unit patients revealed by auditory brain-stem potentials.

The relations between clinical illness and auditory response (as revealed by auditory brain-stem potentials) were prospectively studied in a neonatal intensive care unit. Forty-nine tests were performed on 29 infants with gestational age 24 to 43 weeks and birth weight 530 to 3,380 gm. Auditory test results were classified as pass or fail, depending on the presence or absence of wave V at a latency of 7 to 11 ms in response to clicks 60 dB above the normal adult threshold. Six patients failed and 23 patients passed. The failures were not correlated with excessive noise exposure or ototoxic medication. Five of the patients who failed had intracranial hemorrhage. Routine screening of infants in the NICU for auditory impairment is a clinically feasible and useful procedure.

Brain Stem↗
PubMed1980

Word memory in non-psychotic depression.

Two diverging explanations can be given for the fact that depressed persons often show deficits on verbal learning tasks: (a) researchers have suggested that memory deficits are the result of interference in the transfer from short- to long-term memory; (b) other researchers have suggested that depressives may not have cognitive deficits but may instead simply show deficits in performance. The present study assessed differences in recognition memory, free recall, organization in multitrial free recall, and final free recall among short-term and long-term non-psychotic depressives (ns = 15) to determine whether such depressed adults show deficits on verbal learning tasks. No verbal learning deficits wee demonstrated for 30 depressives relative to 30 nondepressives. The implications of these findings are discussed in terms of interference and the possibility that poor verbal learning in depression is a problem of performance and not learning.

Adult↗
PubMed1979

Psychiatric aspects of shoplifting.

Clinical evidence of depression present for some months before an episode of shoplifting without criminal intent was found in all 17 patients interviewed after the offence. The person at risk would appear to be a depressed middle-aged woman with a passive-dependent personality, married to an ineffectual rejecting husband who is unable to meet her dependency in times of crisis. Recognition of her depression and appropriate intervention are essential if a criminal deed is to be avoided.

Age Factors↗