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Biomedical subjects

K Harvey

Publications and source records attributed to K Harvey.

At least 55 records · Page 3Linked to original sources
PubMed1994

Parallel up-regulation of CD11B and CD45 on neutrophilic leukocytes exposed to soluble factors of oral pathogens.

We tested culture supernatants from a battery of oral bacterial strains for their ability to influence the expression of CD11b and CD45 on the neutrophil plasma membrane. Several bacterial extracts stimulated the up-regulation of both CD11b and CD45 simultaneously. Two supernatants in particular (a clinical isolate of A. actinomycetemcomitans and F. nucleatum ATCC25586) potently stimulated the deployment of CD11b and CD45 from their intracellular storage site to the plasma membrane. Both supernatants inhibited superoxide release stimulated by exposure of neutrophils to formyl methionyl leucyl phenylalanine (FMLP) but had variable effects on superoxide release stimulated by phorbol myristate acetate (PMA). The ability of products of oral bacteria to modulate neutrophil plasma membrane antigen composition may regulate functional reactivity and thus be an important factor in the pathogenesis of periodontal infection and inflammation.

Antigens, CD↗
PubMed1993

Pharmacokinetics and serum bactericidal titers of ciprofloxacin and ofloxacin following multiple oral doses in healthy volunteers.

Fourteen adult males participated in a randomized three-way crossover study to compare the pharmacokinetics and serum bactericidal titers (SBTs) of 500 mg of ciprofloxacin (regimen A), 750 mg of ciprofloxacin (regimen B), and 400 mg of ofloxacin (regimen C) administered every 12 h for seven doses. Mean steady-state peak concentrations in serum for regimens A, B, and C were 3.0, 4.4, and 6.5 micrograms/ml, respectively (P < 0.01, all comparisons) and mean half-lives were 4.5, 4.3, and 6.5 h, respectively (P < 0.05, C versus A and B). Mean steady-state areas under the concentration-time curve were 14.1, 21.1, and 48.1 micrograms/h/ml for regimens A, B, and C, respectively (P < 0.05, all comparisons). SBTs were determined at different times postdose for three isolates each of Streptococcus pneumoniae, Staphylococcus aureus, Escherichia coli, Enterobacter cloacae, and Pseudomonas aeruginosa. Mean steady-state peak SBTs for regimens A, B, and C, respectively, were as follows: S. pneumoniae, < 1:2, 1:8, 1:8, S. aureus, 1:16, 1:16, 1:16; E. coli, 1: > or = 128, 1: > or = 128, 1:64; E. cloacae, 1: > or = 128, 1: > or = 128, 1:64; P. aeruginosa, 1:8, 1:8, 1:2. These differences in SBTs within each genus were statistically significant. The majority of predicted SBTs were within one dilution of measured SBTs. Areas under the serum bactericidal time curves for E. coli, E. cloacae, and P. aeruginosa were significantly higher for ciprofloxacin; areas under the serum bactericidal time curves for S. pneumoniae and S. aureus were significantly greater for ofloxacin. Ofloxacin achieved higher concentrations in serum than ciprofloxacin, but differences in in vitro activity were a more important determinant of SBTs.

Administration, Oral↗
PubMed1992

Beta endorphin release in patients after spontaneous and provoked acute myocardial ischaemia.

BACKGROUND: In animal models of circulatory shock and heart failure concentrations of the endogenous opioid peptide beta endorphin are raised and opioid receptor blockade improves haemodynamic variables and survival. This study was performed to identify whether acute myocardial ischaemia provokes the release of beta endorphin in humans. METHODS: Observational study in a university cardiology centre. Serial measurements of beta endorphin made by specific radioimmunoassay were correlated with other clinical and neuroendocrine variables that were measured prospectively. Fifty five patients with acute myocardial ischaemia and 26 patients undergoing elective coronary angioplasty of the left anterior descending coronary artery were studied. RESULTS: beta endorphin concentrations were raised above the upper limit of normal in 31/42 (74%) patients with confirmed myocardial infarction, 3/13 (23%) patients with unstable angina, and 10/24 (42%) patients after coronary angioplasty. There was no evidence of myocardial release of beta endorphin. There were significant positive correlations between beta endorphin and the concentrations of adrenocorticotrophic hormone, cortisol, and arginine vasopressin. In patients with acute myocardial ischaemia there was a significant positive correlation between the peak concentrations of creatine kinase and beta endorphin but no correlation with visual analogue scores of the intensity of chest pain. The highest beta endorphin concentrations were seen in patients whose clinical course was complicated by the development of heart failure. CONCLUSIONS: beta endorphin release is a component of the neuroendocrine activation associated with myocardial ischaemia/infarction.

Acute Disease↗
PubMed1991

PBS charges.

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Australia↗
PubMed1987

The nasopharynx and adenoid in children with glue ear compared with normal controls.

This study was designed to demonstrate whether any differences could be detected in the nasopharyngeal soft tissue size and postnasal space airway in children with glue ear compared with controls. Lateral cephalometric radiographs of 34 children with bilateral glue ear confirmed by paracentesis were compared with those of normal children matched for age and sex. There was no difference in the measurement of adenoid depth between the 2 groups. However, it was found that the palatal airway size was significantly smaller in children with bilateral glue ear than in normal children. Reduction in the palatal airway to 4 mm or less is found in most cases with bilateral glue ear, but only in 15% of normal controls.

Adenoids↗
PubMed1986

Drug sensitivity of non small cell carcinoma of lung by clonogenic assay in several media.

Lung tumours of non small cell pathology were cultured by clonogenic assay in several media. Culture was successful in spleen conditioned medium, but only 57% grew and low plating efficiencies (PE) meant that only 23% of the original number produced significant drug results. Comparison of rat erythrocyte lysate (REL) medium with serum free defined medium (HITES) and HITES + 10% FBS demonstrated clear enhancement of PE in REL although growth was 100% successful in all these media. Ninety-three percent of samples tested against drugs in REL produced significant results. A later comparison of REL with McCoy's 5A + rbc +/- hydrocortisone produced relatively poor culture success for these 3 media and equivocal growth patterns. Low PE was attributed to age of rats used for rbc. Vindesine and cis-platinum cytotoxicity in spleen conditioned medium were 61% and 15% sensitivity respectively. These do not concur with clinical experience but the figures for overt resistance, at 39% and 69%, correspond with expected non-responders to these regimes. Drug testing in REL produced figures correlating more closely with clinical performance at 45% sensitivity to platinum and 36% of patients sensitive to both drugs, but the vindesine sensitivity at 55% is again discrepant with performance of this drug as a single agent.

Carcinoma, Non-Small-Cell Lung↗
PubMed1985

MRSA revisited.

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Humans↗
PubMed1984

Effects of acute marijuana smoking on pulse rate and mood states in women.

The effects of marijuana cigarette (1.8% THC) smoking on pulse rate and mood were studied under double-blind placebo-controlled conditions in 28 adult female volunteers during the follicular, luteal, and ovulatory phases of the menstrual cycle. Statistically significant increases in pulse rate, subjective levels of intoxication, and the POMS confusion factor occurred after marijuana smoking. However, no statistically significant differences for any measure were observed following marijuana smoking as a function of menstrual cycle phase. Subjects with a past history of intermittent marijuana use (five or less times weekly) had significantly higher pulse rates, subjective levels of intoxication, and POMS confusion factor scores than did subjects with a past history of regular (six or more times weekly) marijuana use. Persistence of marijuana-induced changes in pulse rate, intoxication, and confusion were also of longer duration for subjects with a past history of intermittent marijuana smoking. The influence of past history of marijuana use on marijuana-induced alterations in pulse rate, intoxication, and mood for females appears to be similar to males. These similarities are not attenuated as a function of the menstrual-cycle phase of females.

Adult↗
PubMed1984

Orthodontic force characteristics of open coil springs.

Applications of open coil springs in orthodontic tooth movement are many and varied. Current descriptions of force production by open coil springs are based upon force values produced in series of discrete compression tests. It was the purpose of this study to analyze and compare open-coil-spring force production from continuous load-deflection curves, thereby assisting the clinician in the selection of the ideal spring for a given application. Load-deflection curves were generated for open coil springs of various wire diameters and lumen sizes, as well as four wire alloys from three manufactures. Testing was performed on an Instron test machine using 0.016 inch round and 0.018 by 0.022 inch rectangular arch wires. With a constant lumen size, an increase in wire size produced an increase in force at a given activation. With a constant wire size, an increase in lumen size produced a decrease in force at a given activation. The effect of the arch wire size and shape was not significantly different for the coil springs with the smaller lumen sizes. For the larger lumen sizes, the springs used with the rectangular arch wire manifested a greater linear range than those used with the smaller arch wire. The difference between the load-deflection characteristics of the coil springs from different manufacturers was attributed to the difference in the pitch of the coils.

Equipment Design↗