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Biomedical subjects

J Davidson

Publications and source records attributed to J Davidson.

At least 199 records · Page 11Linked to original sources
PubMed1988

Mandibulotomy and radical radiotherapy: compatible or not?

The mandibular swing, as an approach to upper aerodigestive tract malignancies, has been gaining popularity in recent years. Little has been reported in the literature as to the feasibility of this procedure in subjects having received radical preoperative radiotherapy. The preliminary results of a retrospective analysis of 23 subjects, 70% of whom received radical preoperative radiotherapy, is presented. There was no statistically significant difference between the complication rates in the irradiated and nonirradiated subject populations. All subjects, ultimately, were orally rehabilitated.

Adult↗
PubMed1988

Epidemiology of hearing impairment in childhood.

Consensus about the etiology and prevalence of childhood hearing loss (HL) is difficult to discern. Genuine effects, such as those attributable to environment, are obscured by inconsistencies in data collection and analysis techniques. Prevalence, for example, depends upon test type, hearing loss criteria and age at evaluation. An etiologic classification which clarifies the interaction between time of insult, causation and time of expression of hearing loss is proposed and used for selective review. Much sensorineural hearing loss (SNHL) is of unknown cause. Where the cause is known, genetic causes are common, and influenced by consanguinity. Infectious causes of HL reflect seasonal and epidemic fluctuation, as well as geographic and temporal variation. Non-infectious causes vary more closely with differences in the environment and level of health care. In the western world, the most common cause of conductive hearing loss (CHL) is serous otitis media. In many developing regions, middle ear disease abounds and often is of the dangerous cholesteatomatous type. Certain populations are intermediate, with acute suppurative and chronic otitis media being almost endemic, yet rarely cholesteatomatous.

Adolescent↗
PubMed1988

The response of depressed inpatients to isocarboxazid.

Fifty-six inpatients with unipolar depression completed treatment with isocarboxazid. In comparing the differences between responders and nonresponders, it was found that psychomotor retardation, pathological guilt, daily persistence of unremitting symptoms, phobic anxiety, dexamethasone suppression test nonsuppression, and neuroticism were significantly more common among nonresponders. Reactivity of mood, blaming others, and extraversion were more common in responders. Total endogenous depression scores on the Newcastle 1, Newcastle 2, and Michigan scales were also significantly higher in nonresponders. Attained platelet monoamine oxidase inhibition was similar in both groups.

Adult↗
PubMed1987

Human immunodeficiency virus and drug misuse: the Edinburgh experience.

During 1985 many drug abusers who lived in Edinburgh were found to be infected with the human immunodeficiency virus (HIV). As a result an alternative counselling and screening clinic for testing for antibodies to HIV was established for use by drug abusers. Four hundred and forty one patients were counselled in the first year, and over 60% were either drug abusers or their sexual contacts. One hundred and fourteen (26%) patients were positive for HIV antibody, and 100 (88%) of these were current or former drug abusers. The HIV seropositivity rate in drug abusers was 52% but was only 7% in their sexual contacts. Services were provided for these people as well as counselling before and after the test. The cost of this counselling service for the first year was 27,000 pounds or 61.22 pounds per patient. The unexpected mobility of 23% of the Edinburgh drug abusers, particularly to other areas of Britain, suggests that similar services need to be set up elsewhere.

Acquired Immunodeficiency Syndrome↗
PubMed1987

The pyrogenic actions of the interferon-inducer, polyinosinic:polycytidylic acid are antagonised by ketoprofen.

The effect of various doses of polyinosinic:polycytidilic acid (Poly I:C) in the range (0.25-250 micrograms/kg) administered i.v. on the body temperature of rabbits was investigated. The effect of ketoprofen on the febrile responses was also studied. The threshold dose of Poly I:C administered which produced a fever was between 0.25 and 0.5 micrograms/kg and a double-sigmoidal dose-response relationship was observed. A sigmoidal relationship was obtained with lower doses from 0.25 micrograms/kg to an apparent maximum with 2.5 micrograms/kg and another with higher doses from 5 micrograms/kg to another apparent maximum with 250 micrograms/kg. Ketoprofen (3 mg/kg) given s.c. 15 min prior to Poly I:C inhibited the production of fever. Ketoprofen administered after the onset of fever resulted in an immediate deffervescence. These results suggest that febrile responses to Poly I:C involve prostaglandin biosynthesis.

Animals↗
PubMed1987

Dexamethasone pre-treatment is antipyretic toward polyinosinic: polycytidylic acid, lipopolysaccharide and interleukin 1/endogenous pyrogen.

The effect of intravenously injected dexamethasone on the febrile response of rabbits to Polyinosinic: Polycytidylic acid (Poly I:C), lipopolysaccharide (LPS) and interleukin 1/endogenous pyrogen (IL1/E.P.) was studied. Dexamethasone (1 mg/kg) attenuated the febrile response to Poly I:C (5 micrograms/kg) but only if administered between 0.5 to 2 h before Poly I:C. If it was given after Poly I:C this resulted in a potentiation of the fever. Antagonism of the febrile response to Poly I:C by dexamethasone pre-treatment was dose-dependent and a maximal effect was observed with 3 mg/kg, a higher dose (6 mg/kg) resulted in a lesser effect on the Poly I:C fever. DEX injected alone (0.5-6 mg/kg) did not have any effect on body temperature. Fevers in response to LPS (50 ng/kg) and IL1/E.P. were also attenuated by dexamethasone. It is concluded that Poly I:C, LPS and IL1/E.P. induce fever by a common mechanism which is either directly or indirectly inhibited by dexamethasone.

Animals↗
PubMed1987

Correlation of immunocytochemically demonstrated estrogen receptor distribution and histopathologic features in primary breast cancer.

Frozen sections of breast cancer specimens from 114 patients were assayed for the presence of estrogen receptor (ER) with an immunocytochemical method (ERICA). Significant positive correlations were found between receptor status and various pathologic features, including better histologic degrees of differentiation (P less than 0.001), smaller tumor cell size (P = 0.001), and lower levels of either tumor necrosis (P less than 0.001) or lymphocytic infiltration (P less than 0.001). There was a significant relationship between tubular formation and ER positivity (P = 0.003). This study confirms the results from some previous studies in which ER, assessed by biochemical means, has shown a correlation with good-prognosis pathologic features.

Adult↗
PubMed1987

The DST and posttraumatic stress disorder.

The dexamethasone suppression test (DST) was administered to 28 male combat veterans with posttraumatic stress disorder. Six subjects (21%) were nonsuppressors. The nonsuppression rates for the subgroups with and without major depressive disorder according to the Research Diagnostic Criteria were 50% and 6%, respectively. The authors conclude that cortisol nonsuppression is rare in posttraumatic stress disorder unless there is concomitant major depression.

Adolescent↗
PubMed1987

Functional assessment after laryngotracheoplasty.

Laryngotracheal stenosis is a difficult problem to manage. Functional assessment is measured primarily on the ability to successfully decannulate the patient. In an effort to identify reliable, objective parameters for postoperative functional assessment, we present a retrospective study of 10 postlaryngotracheoplasty patients. All subjects underwent analysis with computerized tomography, translaryngeal manometry, acoustic reflection, flow volume loops (FVL), and voice analysis. Our results led us to conclude that accurate functional assessment is best provided by use of a combination of CT and spectral voice analysis.

Adult↗
PubMed1987

The spatial distribution of neurons and glia in human cortex based on the poisson distribution.

A method was devised that employs deviations from the Poisson distribution to analyze the spatial arrangement of neurons and glia in human cerebral cortex. A field of randomly distributed points equal in number of a sample field of neuronal or glial cells is generated by computer, and the proportion of cells in the sample field that are closer to the nearest neighboring cells than to the nearest randomly distributed point is determined. We call this proportion the "Poisson ratio." When the cells are randomly distributed, the Poisson ratio is equal to 0.5. If the Poisson ratio is less than 0.5, the cells are farther away from one another than a random distribution would predict (exclusionary pattern); if the Poisson ratio is greater than 0.5, the cells are closer to one another than a random distribution would predict (clustering). A simple nonparametric statistical test is used to determine the significance of differences in the ratios. This method was applied to samples of human cerebral cortex in order to test the hypothesis that patients with schizophrenic psychosis may have an altered pattern of neuronal clustering. The analysis revealed that there is no difference in the nearest-neighbor distribution of either neurons or glia between psychotic patients and controls. It was found, however, that there is a highly significant difference in the spatial distribution of neurons versus glia in human cerebral cortex. Neurons of layers II to VI in the human cortex show greater-than-expected distances among them and are distributed according to an exclusionary pattern, while neurons in layer I show a clustering pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Cortex↗
PubMed1987

An outpatient evaluation of phenelzine and imipramine.

Phenelzine and imipramine were evaluated in a 5-week double-blind study of outpatients with major depression. Median daily doses of phenelzine 75 mg and imipramine 150 mg were employed. Of 27 patients 26 completed the 5-week study. Both drugs produced an equal overall effect, as measured by the Hamilton Rating Scale for Depression (HAM-D) and the Beck Depression Inventory (BDI). When patients were grouped on the basis of panic attack symptoms, phenelzine was found to be more effective than imipramine (p less than .05 for all patients on the BDI; p less than .05 for women on both rating scales).

Adult↗
PubMed1987

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Information Systems↗