Search PubMed⌕ Search

Biomedical subjects

J C Stewart

Publications and source records attributed to J C Stewart.

At least 55 records · Page 3Linked to original sources
PubMed1990

Re-examination of CPM performance and neglect in lateralized brain injury.

The current study examines the effects of lateralized brain injury on Raven's Coloured Progressive Matrices (CPM) performance. Archival data on 106 unilateral brain-damage patients, 59 with right hemisphere damage and 47 with left, was utilized to examine four aspects of differential performance. Right brain-damaged subjects performed significantly lower than left brain-damaged subjects overall on the CPM. They also showed evidence of a higher incidence of and greater severity of hemi-neglect. After partialling out the effects of hemi-neglect, the subject groups were no longer significantly different on overall CPM performance. Evidence supporting the presence of heterogeneous subtests was not found. The results support the emerging pattern in research findings indicating that hemi-neglect plays a central role in differential performance. The CPM appears limited in its application and interpretation for patients with hemi-neglect.

Adult↗
PubMed1990

Treatment of recurrent herpes simplex labialis with oral acyclovir.

In a double-blind, randomized, patient-initiated clinical trial, 174 nonimmunocompromised patients with a history of virus-culture-confirmed herpes simplex labialis were treated with acyclovir capsules, 400 mg five times daily for 5 days, or placebo capsules. For 97% of the patients, treatment started within 1 h of the first sign or symptom of a recurrence. The frequency of positive lesion virus cultures was significantly lower among acyclovir-treated subjects (29/114, 25%) than among placebo-treated subjects (29/60, 48%; P = .004). Drug treatment did not affect the development of lesions, measured by the frequency of macular and papular (aborted) lesions and mean maximum lesion size. However, acyclovir hastened lesion resolution among the patients who could start treatment in the prodrome or erythema lesion stage. For this group, the mean duration of pain was reduced by 36% (P = .02) and the mean healing time to loss of crust by 27% (P = .03). Thus, oral acyclovir alleviated some of the clinical manifestations of herpes simplex labialis.

Acyclovir↗
PubMed1990

Early application of topical 15% idoxuridine in dimethyl sulfoxide shortens the course of herpes simplex labialis: a multicenter placebo-controlled trial.

In a double-blind, randomized, patient-initiated treatment study at five medical centers, 301 immunocompetent patients experiencing a recurrence of herpes labialis were treated with topical 15% idoxuridine (IDU) in dimethyl sulfoxide (DMSO), 80% DMSO control solution, or 2% DMSO control solution. IDU did not prevent the development of lesions but significantly accelerated lesion resolution in comparison with the combined control groups. For the total population, the mean duration of pain was reduced by 1.3 days (35%, P = .01) and the mean healing time to loss of crust by 1.7 days (21%, P = .004). Analysis of subpopulations revealed that the beneficial activity of the treatment was concentrated among the patients who began treatment in the prodrome or erythema lesion stage. For these patients, the mean duration of pain was reduced by 1.8 days (42%, P = .08) and the mean healing time to loss of crust by 3.3 days (38%, P less than .001). If only patients with classic herpes lesions (vesicle, ulcer, or crust formation) were considered, there was a greater drug effect on the duration of pain (reduction by 2.6 days, 49%; P = .03) and the mean healing time to normal skin was significantly shortened (reduction by 2.3 days, 23%; P = .004). Adverse reactions to the medication were minimal.

Administration, Topical↗
PubMed1989

Meta-analysis of placebo-controlled studies of the efficacy of Epogam in the treatment of atopic eczema. Relationship between plasma essential fatty acid changes and clinical response.

Gamma-linolenic acid in the form of a particular variety of evening primrose oil (Epogam) has been reported of value in the treatment of atopic eczema. Nine controlled trials of evening primrose oil were performed in eight centres. Four of the trials were parallel and five cross-over. Doctors and patients assessed the severity of eczema by scoring measures of inflammation, dryness, scaliness, pruritus and overall skin involvement. Individual symptom scores were combined to give a single global score at each assessment point. In the analysis of the parallel studies, both patient and doctor scores showed a highly significant improvement over baseline (P less than 0.0001) due to Epogam: for both scores the effect of Epogam was significantly better than placebo. Similar results were obtained on analysis of the cross-over trials, but in this case the difference between Epogam and placebo in the doctors' global score, although in favour of Epogam, failed to reach significance. The effects on itch were particularly striking. There was no placebo response to this symptom, whereas there was a substantial and highly significant response to Epogam (P less than 0.0001). When the improvements, or otherwise, in clinical condition were related to changes in plasma levels of dihomogammalinolenic and arachidoni acids, it was found that there was a positive correlation between an improvement in clinical score and a rise in the fatty acid levels.

Adolescent↗
PubMed1989

Hypercholesterolemia in the aviator.

Cholesterol is becoming increasingly implicated in the pathogenesis of coronary artery disease (CAD). We reviewed lipid physiology, National Institute of Health recommendations, current USAF policies, and the lipid profiles of four active duty flying squadrons. A significant number of fliers are in a high or extremely high risk category for the development of CAD based on NIH criteria.

Adult↗
PubMed1989

Deep venous thrombosis in the military pilot.

Deep venous thrombosis (DVT) is a common clinical problem. The aeromedical dispositions of three United States Air Force pilots with lower extremity deep venous thrombosis from Altus Air Force Base, OK are discussed, as well as the etiology, diagnosis, and treatment of this problem.

Adult↗
PubMed1988

Isolation of soybean trypsin inhibitors by affinity chromatography on anhydrotrypsin-Sepharose 4B.

By repeated treatments of trypsin with phenylmethylsulfonyl fluoride (PMSF), followed by base elimination of PMS from the PMS-trypsin, a catalytically inactive anhydrotrypsin preparation of low (less than 1%) active trypsin content was obtained. Inactive material was removed by affinity chromatography on trypsin inhibitor-Sepharose 4B and the purified anhydrotrypsin with full binding capacity for trypsin inhibitors was coupled to cyanogen bromide-activated Sepharose 4B. When used below its maximum capacity for trypsin inhibitors the anhydrotrypsin-Sepharose-4B affinity column absorbed both classes of inhibitors present in soybean. When overloaded, the Kunitz type was bound preferentially. Based on this observation, conditions for the partial separation of the two types of inhibitors were worked out.

Chromatography, Affinity↗
PubMed1988

Office hypertension in the military aviator.

High blood pressure is a common problem in aerospace medicine. The standard for evaluating blood pressure in the United States Air Force is the routine blood pressure check and the 5-d blood pressure check. There is a subset of fliers with "office hypertension" who may be on medication needlessly. An Air Force "office hypertensive" is discussed. Home blood pressure recording and 24-h ambulatory blood pressure monitoring will identify these patients who may then be managed more appropriately.

Adult↗
PubMed1986

Immunohistochemical study of idiopathic histiocytosis of the mandible and maxilla.

Recent evidence suggests that the proliferative cells of idiopathic histiocytosis may be derived from Langerhans cells. In this study, antisera to S-100 protein, HLA-DR (la-like) antigen, muramidase, and alpha 1-antichymotrypsin were tested on formalin-fixed, paraffin-embedded tissue from nine cases of idiopathic histiocytosis using an immunoperoxidase technique. Tumor cells were positive for S-100 protein and HLA-DR antigen but negative for muramidase and alpha 1-antichymotrypsin. Mononuclear phagocytes were positive for HLA-DR antigen, muramidase, and alpha 1-antichymotrypsin but negative for S-100 protein. The immunohistochemical staining pattern of the tumor cells in these cases of idiopathic histiocytosis is similar to that seen for normal Langerhans cells. When these results are coupled with electron microscopic and histochemical data, it would appear that the origin of cells in idiopathic histiocytosis is from the Langerhans cell or its precursor. Thus, this condition might be better designated "Langerhans cell disease."

Chymotrypsin↗
PubMed1986

Topical application of isotretinoin gel improves oral lichen planus. A double-blind study.

In a double-blind study, 20 patients with oral lichen planus were treated twice daily with 0.1% isotretinoin gel or the vehicle alone for two months. Subsequently, patients who used the placebo received the active preparation for another two months. Patients treated with the active medication displayed significantly greater improvement than patients receiving the placebo. Patients who were treated initially with the placebo showed statistically significant improvement after receiving the topical isotretinoin treatment for two months. Side effects from using the gel were primarily a transient burning sensation or irritation on initial application.

Administration, Topical↗
PubMed1985

Immunohistochemical staining of Langerhans cells and macrophages in oral lichen planus.

Twenty patients with clinically and microscopically confirmed lichen planus were studied immunohistochemically. Monoclonal antibody to HLA-DR antigens and polyclonal antisera to S-100 protein and muramidase were applied to paraffin-embedded sections for the purpose of elaborating on the pathogenesis of this disease. Trypsin incubation of sections was also done in order to determine its effect on immunostaining. Langerhans cells were identified with anti-S-100 and anti-HLA-DR, and macrophages were identified with antimuramidase and anti-HLA-DR. Keratinocytes also expressed HLA-DR membrane activity in lichen planus tissue. Trypsinization significantly improved the expression of S-100 protein and muramidase antigens. It was concluded that Langerhans cells, macrophages, and keratinocytes play important roles in antigen processing and/or phagocytosis during the natural history of this disease.

Follow-Up Studies↗
PubMed1983

Purification of the major endoglucanase from Aspergillus fumigatus Fresenius.

Aspergillus fumigatus (Fresenius), IMI 246651, A.T.C.C. 46324, produces two beta-glucosidase enzymes, cotton-solubilizing activity, xylanase and endoglucanase enzymes which can be separated by gel-filtration chromatography. The major endoglucanase does not bind to concanavalin A-Sepharose and does not stain with periodic acid/Schiff reagent. It is homogeneous on polyacrylamide isoelectric focusing (pI = 7.1) and has a mol.wt. of 12500 by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The endoglucanase produces glucose and a mixture of oligosaccharides from cellulose; the purified enzyme has a small dextranase activity. It is stable at 50 degrees C and pH 6.

Aspergillus fumigatus↗
PubMed1983

A survey of the nutritional and haemagglutination properties of legume seeds generally available in the UK.

Eighty-five samples from fifteen different legume seed lines generally available in the UK were examined by measurements of their net protein utilization by rats and by haemagglutination tests with erythrocytes from a number of different animal species. From these results the seeds were classified into four broad groups. Group a seeds from most varieties of kidney (Phaseolus vulgaris), runner (Phaseolus coccineus) and tepary (Phaseolus acutifolius) beans showed high reactivity with all cell types and were also highly toxic. Group b, which contained seeds from lima or butter beans (Phaseolus lunatus) and winged bean (Psophocarpus tetragonolobus), agglutinated only human and pronase-treated rat erythrocytes. These seeds did not support proper growth of the rats although the animals survived the 10 d experimental period. Group c consisted of seeds from lentils (Lens culinaris), peas (Pisum sativum), chick-peas (Cicer arietinum), blackeyed peas (Vigna sinensis), pigeon peas (Cajanus cajan), mung beans (Phaseolus aureus), field or broad beans (Vicia faba) and aduki beans (Phaseolus angularis). These generally had low reactivity with all cells and were non-toxic. Group d, represented by soya (Glycine max) and pinto (Phaseolus vulgaris) beans, generally had low reactivity with all cells but caused growth depression at certain dietary concentrations. This growth depression was probably mainly due to antinutritional factors other than lectins. Lectins from group a seeds showed many structural and immunological similarities. However the subunit composition of the lectin from the tepary bean samples was different from that of the other bean lectins in this or any other groups.

Animals↗
PubMed1982

Plasma and cerebrospinal fluid pharmacokinetics of acivicin in Ommaya reservoir-bearing rhesus monkeys.

Acivicin was administered iv to rhesus monkeys bearing Ommaya reservoirs, and serial blood and cerebrospinal fluid (CSF) samples were collected and analyzed to determine the time course of drug concentrations in these body fluids. After iv doses of 4 or 20 mg/kg (50 or 250 mg/m2), acivicin plasma concentrations demonstrated a rapid initial decline (distribution phase), and then declined exponentially with a terminal (elimination phase) half-life of 3--4 hrs. CSF concentrations increased over a period of 2--2.5 hrs, reaching peak values of 2.0--2.7 micrograms/ml at 20 mg/kg and 0.3--0.5 microgram/ml at 4 mg/kg; thereafter, CSF levels declined in parallel with plasma, with a CSF/plasma concentration ratio of 0.10--0.17. A three-compartment pharmacokinetic model gave a close fit of predicted and observed plasma and CSF concentration data. Significant and predictable CSF penetration by iv administered acivicin in monkeys is consistent with observation of CNS side effects in patients in the phase I clinical trial and suggests that acivicin should be evaluated in the treatment of CNS malignancies and metastases.

Animals↗