Search PubMed⌕ Search

Biomedical subjects

S Rogers

Publications and source records attributed to S Rogers.

At least 307 records · Page 17Linked to original sources
PubMed1981

Relapse rate and long-term management of plaque psoriasis after treatment with photochemotherapy and dithranol.

The relapse rate of plaque psoriasis after initial clearing with the "Ingram" dithranol regimen or photochemotherapy was comparable when no maintenance treatment was given. It was estimated that psoriasis recurs to half of its pretreatment extent after about six months in half the patients. Maintenance treatment with photochemotherapy once a week or once every three weeks was useful in reducing the relapse rate. This study failed to show any statistical difference in relapse rates between these two maintenance schedules. If this finding turns out to be true over longer periods of study the maintenance schedule entailing treatment once every three weeks with its lower cumulative dose of long-wave ultraviolet light will clearly be preferable. The psoriasis in most patients was under better overall control with maintenance treatment than with intermittant clearing courses given when the extent of the psoriasis had become unacceptable to them. There was, however, a group of roughly one-fifth of patients who remained in satisfactory remission for over 16 months after initial clearing. Regular maintenance treatment was unnecessary in them. Much more information is needed on response to treatment in subgroups of patients to permit recognition from the start of which patients are likely to have long remission and which are not.

Adult↗
PubMed1981

Epileptic discharges produced in monkeys by injection of spleen cells from rabbits immunised with monkey brain.

Cell suspension from the spleen of rabbits immunised with monkey brain gave rise to epileptic discharges in the monkey when injected intracortically, except in the case of one injection from a rabbit not recently given a booster treatment. In contrast, cell suspensions from the spleen of unimmunised rabbits, or of a rabbit immunised with a non-brain material, in all cases failed to be effective. The epileptic discharges began about 2 weeks after injection, were variable in frequency, and lasted throughout the period of recording.

Animals↗
PubMed1981

Mutagenicity of a series of hexacoordinate rhodium(III) compounds.

19 rhodium(III) compounds have been tested for genetic damaging capabilities using an Escherichia coli differential repair assay and for mutagenicity in the strains of Salmonella typhimurium. 10 of these were active in both assays. Presence of the plasmid pKM101 was required for mutagenicity in Salmonella. Both the composition of the ligands and the free-dimensional structures of the coordination complexes profoundly affect genetic activity. In general, the structure--activity relationships appear to favor complexes with (1) a +1 charge, (2) 2-relatively labile leaving groups with 4 more strongly bonded amine ligands, and (3) a relatively slow rate of exchange of the ligands which is characteristic of substitutionally inert coordination complexes.

Escherichia coli↗
PubMed1981

Mutagenicity of a series of hexacoordinate chromium (III) compounds.

17 chromium(III) compounds have been tested for DNA-damaging capabilities using an E. coli differential repair assay and for mutagenicity in strains of Salmonella typhimurium. 4 of these compounds were active in both assays. Another 4 compounds were positive only in the repair assay and 9 were devoid of activity in both assays. Most of the doubly active complexes contain aromatic amine ligands like 2,2'-bipyridine and 1,10-phenanthroline. Closely related complexes of ligands derived from saturated amines are much less active. It appears that chromium(III) in the proper ligand environment can have considerable genetic toxicity and could represent one of the several possible ultimate species in a mechanism for chromium mutagenesis and carcinogenesis.

Chromium↗
PubMed1981

Blood lactate concentration following maximum exercise in trained subjects.

The time when blood lactate reaches peak concentration following maximum exercise is unclear. The post exercise venous blood lactate concentration was determined serially for 30 minutes in 13 trained men following maximum exercise on a motor driven treadmill. Lactates were determined enzymatically in duplicate. The VO2 max and percent body fat was 65.1 +/- 4.8 ml.kg-1.min-1 and 11.4 +/- 1.4, respectively. The venous lactate reached a peak concentration at the 6th minute (14.2 mmol.L-1) of an inactive recovery, and declined linearly thereafter to reach a concentration of 7.43 +/- 0.60 mmol.L-1 at the 30th minute. The net rate of lactate removal was .30 mmol.L-1.min-1. Statistical analysis found no significant difference in lactate concentration during the 4th, 5th and 6th minute post exercise, indicating that these post exercise times may be appropriate to sample venous blood for peak lactate concentration.

Adult↗
PubMed1981

Changing activities of galactose-metabolizing enzymes during perfusion of suckling-rat liver.

The specific activities of the galactose-metabolizing enzymes, galactokinase (EC 2.7.1.6), galactose-1-phosphate uridyltransferase (EC 2.7.7.12), and UDPgalactose 4-epimerase (EC 5.1.3.2), in suckling-rat livers perfused for 90 min with 1 and 4 mM galactose fluctuate significantly with a different pattern of change for each enzyme. Perfusion for 30 min with galactose resulted in a significant increase of transferase specific activity followed by a precipitous decline to about one-fifth of the activity in unperfused liver at 90 min. The increase in transferase activity was also observed when D-glucose was perfused but not when L-glucose, D-fructose, D-xylose, or D-ribose was added to the perfusate. No such changes in transferase activity were observed when adult-rat liver was perfused with galactose. Epimerase activity in the suckling-rat liver was relatively low, and the changes in its activity correlated best with the uptake rate of galactose. The perfused suckling-rat liver may provide a model system for examination of factors that modulate the specific activity of galactose-metabolizing enzymes and effect the metabolism of galactose.

Animals↗
PubMed1981

Itch following photochemotherapy for psoriasis.

Itch was measured quantitatively as nocturnal scratch in 12 patients with psoriasis treated with 8-methoxypsoralen and UVA and in 7 treated with dithranol. Three of those treated with PUVA showed an increase in nocturnal limb movement which was mostly due to itch but partly due to restlessness. There was little change in nocturnal limb movement in patients treated with dithranol.

Adult↗
PubMed1980

Photochemotherapy of psoriasis: DNA damage in blood lymphocytes.

DNA synthesis assessed by 3H thymidine incorporation was measured in lymphocytes from patients with psoriasis receiving photochemotherapy with 8-methoxypsoralen (8-MOP) and UV-A (PUVA). The emission from the UVA source contained sufficient short wavelengths (UV-B) to impair 3H-thymidine incorporation but could be screened out with clear plastic screens. When lymphocytes were irradiated in vitro in a 1/10 dilution of plasma containing 8-MOP, increasing doses of UV-A produced progressive inhibition of phytohaemagglutinin (PHA)-induced DNA synthesis. Cells from patients given several previous treatments were inhibited significantly more than those from patients receiving their first exposure. This was also true for unirradiated cells sugesting either an accumulation of 8-MOP within cells, persistence of DNA damage or alteration of the lymphocyte population. Lymphocytes removed immediately after patients were irradiated showed less 3H thymidine incorporation than cells taken just prior to irradiation, which confirms that PUVA treatment exerts in vivo effects on circulating lymphocytes.

DNA↗
PubMed1980

Decreased epidermal aryl hydrocarbon hydroxylase and localized pustular psoriasis.

Microsomal aryl hydrocarbon hydroxylase (AHH) activity was measured in suction separated epidermis from forearm skin of thirteen patients with localized palmo--plantar pustular psoriasis and thirteen normal subjects before and after induction by benzanthracene. AHH activity had a mean value of 2 . 32 micrometer 30H-BP/mg microsomal protein/h +/- 0 . 23 (s.e.) in the patients and 3 . 41 +/- 0 . 23 in the normal subjects. AHH induction was also decreased with a mean value of 1 . 15 +/- 0 . 1 (s.e.) compared with 1 . 98 +/-- 0 . 14 for the normal subjects. Since in twelve of the patients the psoriasis had always been localized to the palms and soles, the decreased basal and induced AHH activity appears to be a primary characteristic of psoriatic skin; AHH activity initiate an increase in epidermal cell turnover through modulation of prostaglandin and adenylate cyclase activity.

Adolescent↗
PubMed1979

Interaction of bovine platelets with bovine glomerular basement membrane.

The interaction of bovine platelets with bovine glomerular basement membrane has been studied by aggregometry, transmission and scanning electron microscopy and measurement of [3H] serotonin release. In the absence of added calcium platelets adhere to basement membrane but fail to undergo the release reaction or aggregation. In the presence of 0.2-0.5 mM calcium release of serotonin and complete aggregation of the platelets are observed when sufficient basement membrane is present. Platelets were strongly adhered to the basement membrane surface, the platelet surface in the aggregates closely following the surface of the basement membrane. Platelet morphology in aggregates with basement membrane closely resembled that of platelets from collagen-induced aggregates. Basement membrane differed from collagen in its requirement for calcium for the aggregation and release reactions. In addition purified basement membrane was 1.5-3 fold less active on a weight basis than bovine tendon collagen in promoting aggregation.

Animals↗