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Biomedical subjects

J R Fraser

Publications and source records attributed to J R Fraser.

At least 109 records · Page 6Linked to original sources
PubMed1983

The exanthem of Ross River virus infection: histology, location of virus antigen and nature of inflammatory infiltrate.

The exanthem of epidemic polyarthritis, a disease caused by Ross River (RR) virus, was examined three days after onset of the common erythematous and the rare purpuric forms of the eruption. The dermis showed a light perivascular infiltrate of mononuclear cells in both, with extravasation of erythrocytes in the latter. No immunoglobulins (IgM, IgG, IgA) or complement components (Clq, C3) were detected. Most of the infiltrating cells were T lymphocytes of the T suppressor-cytotoxic class. Their perivascular location, the scarcity of other lymphocytes or phagocytes, and rapid resolution of the rash indicated that the T lymphocytes were responsible for cytotoxic destruction of virus-infected cells. A few monocyte-macrophage cells were identified in the perivascular infiltrate. RR virus antigen was found in the basal epidermal and eccrine duct epithelial cells of both types of lesion and in the perivascular zone of the erythematous lesion, but appeared to have been eliminated from this region in the purpuric lesion. It is suggested that secondary effects of the T-cytotoxic reaction on nearby capillaries are responsible for erythema, oedema and purpura in the exanthem.

Adult↗
PubMed1981

Plasma clearance, tissue distribution and metabolism of hyaluronic acid injected intravenously in the rabbit.

The plasma clearance, tissue distribution and metabolism of hyaluronic acid were studied with a high average molecular weight [3H]acetyl-labelled hyaluronic acid synthesized in synovial cell cultures. After intravenous injection in the rabbit the label disappeared from the plasma with a half-life of 2.5--4.5 min, which corresponds to a normal hyaluronic acid clearance of approx. 10 mg/day per kg body weight. Injection of unlabelled hyaluronic acid 15 min after the tracer failed to reverse its absorption. Clearance of labelled polymer was retarded by prior injection of excess unlabelled hyaluronic acid. The maximum clearance capacity was estimated in these circumstances to be about 30 mg/day per kg body wt. The injected material was concentrated in the liver and spleen. As much as 88% of the label was absorbed by the liver, where it was found almost entirely in non-parenchymal cells. Degradation was rapid and complete, since volatile material, presumably 3H2O, appeared in the plasma within 20 min. Undegraded [3H]hyaluronic acid, small labelled residues and 3H2O were detected in the liver, but there was little evidence of intermediate oligosaccharides. No metabolite except 3H2O was recognized in plasma or urine. Two-thirds of the radioactivity was retained in the body water 24 h later, and small amounts were found in liver lipids. Radioactivity did not decline in the spleen as rapidly as in the liver. The upper molecular weight limit for renal excretion was about 25 000. Renal excretion played a negligible part in clearance. It is concluded that hyaluronic acid is removed from the plasma and degraded quickly by an efficient extrarenal system with a high reserve capacity, sited mainly in the liver.

Animals↗
PubMed1981

Handling the emotional response to disaster: the case for American Red Cross/community mental health collaboration.

This paper presents the theory, rationale, and a working model for integrating professional resources at the time of a disaster. Red Cross and community mental health agencies have worked for too long in parallel. A collaborative approach to meeting the emotional needs of disaster victims makes optimal use of indigenous resources; provides skill and knowledge normally lacking in each agency alone; and helps provide, through early intervention, a preventive factor to thwart long term community distress. Options for maintenance of readiness, local or regional adaptation and piloting are also discussed.

Adjustment Disorders↗
PubMed1981

Specific and non-specific immunological changes in epidemic polyarthritis patients.

T-lymphocytes from epidemic polyarthritis patients exhibited a virus specific proliferative response when exposed to Ross River virus in vitro. The magnitude of this response was greater than that of lymphocytes from asymptomatic seropositive donors. The natural killer cell activity of peripheral blood mononuclear leucocytes from these patients was depressed early in disease but returned to normal levels as the severity of the symptoms decreased. Although no in vivo role can yet be assigned to natural killer cells in epidemic polyarthritis, changes in their activity appeared to be more closely associated with the presence or absence of disease symptoms than were levels of anti-viral antibody or the ability or T-lymphocytes from peripheral blood to proliferate on re-exposure to Ross River virus.

Antibodies, Viral↗
PubMed1981

Cytology of synovial effusions in epidemic polyarthritis.

Examination of synovial fluid in eight patients with epidemic polyarthritis following Ross River virus infection showed cell counts ranging from 1,500 to 13,800 per mm3. Stained smears were notable for a paucity of neutrophils and high proportions of monocytes and vacuolated macrophages, which were further characterised by light and electron microscopy. Ross River virus antigen was detected by specific immunofluorescence in monocytes and macrophages of four cases early in the course of the illness, but intact virus was not identified by electron microscopy or cell culture. No cell-associated C3 component of complement or immunoglobulin of IgM or IgG class was detected in any cell-type. These findings indicate that cell counts and simple smears may be useful in the early diagnosis of suspected epidemic polyarthritis, and provide further information pertinent to the pathogenesis of this disease.

Adolescent↗
PubMed1981

Some in-vitro comparisons of synovial cells dispersed by trypsin from rheumatoid and nonrheumatoid synovium.

Life spans, growth rate, glucose utilisation, response to hydrocortisone, and intracellular activity of lysosomal N-acetyl-beta-glucosaminidase of rheumatoid synovial cells in culture were compared with these properties in nonrheumatoid synovial cells. Except for a small group of RA cells derived from tissue explants, the cells were all isolated by trypsinisation of synovial tissue, either within intact joints or after synovectomy. Cell lines were established by passaging with trypsin. In a study of 56 nonrheumatoid and 24 rheumatoid synovial lines isolated during a 7-year period the latter were found to have a shortened mean life expectancy in culture, though there was wide variation between individual lines. This is in agreement with reported findings from untrypsinised explant-derived synovial lines. However, in the present study mean multiplication rates were identical for nonrheumatoid and rheumatoid synovial cells, and on clear differences could be demonstrated for the other properties studied. No correlation could be found between the life spans of synovial cell lines and the age of the cell donors, whether from rheumatoid or nonrheumatoid sources. Rheumatoid synovial cells isolated from intact joints were notable for especially high proportions of macrophage-like cells and suppression of fibroblasts. In most cases cell lines could not be established from these rheumatoid primary cultures, and in others the lines were short-lived. Early association with relatively high proportions of macrophage-like cells in rheumatoid cultures might thus be important in influencing the establishment and behaviour of synovial cell lines.

Acetylglucosaminidase↗
PubMed1980

Incubation time of epidemic polyarthritis.

The incubation time of epidemic polyarthritis was estimated in 20 patients with evidence of Ross River virus infection after spending less than three weeks in areas of risk. The smallest estimate consistent with all cases was a range of seven to nine days.

Arbovirus Infections↗
PubMed1980

Epidemic polyarthritis acquired in Fiji.

Four cases of epidemic polyarthritis which was acquired in Fiji between April and July of 1979 are described. The manifestations of the illness were similar to those of the disease in Australia. Knowledge of the geographic distribution of this disease can be valuable in diagnosis, but it is likely that its range is not yet fully known.

Adult↗
PubMed1980

Possible genetic determinants in epidemic polyarthritis caused by Ross River virus infection.

HLA D locus-related (DR) antigens and Gm phenotypes were determined in 30 patients with epidemic polyarthritis following Ross River virus (RRV) infection and contrasted with those in comparison series of 119 (DR) and 1220 (Gm) normal subjects. HLA DR7 (46.7% cf. 21.0%) and the heterozygous Gm phenotype a+x+b+ (33.3% cf. 15.3%) were significantly increased in the patients, with relative risks of 3.3 and 2.8 respectively. The occurrence of Gm a+x+b+ was independent of DR7, and conferred a relative risk of 4.3 in DR7-negative patients. Differences found in clinical features, specific lymphocyte proliferative responses and antibody titres did not reach significant levels. The association with DR7 was inversely related to age in residents of an area of moderate endemic risk, and to levels of natural cell-mediated immunity (natural killer cell activity). These correlations point to possible mechanisms by which genetic traits might influence the occurrence or consequence of RRV infection.

Adolescent↗
PubMed1979

Crisis intervention in the court room: the case of the night prosecutor.

Often the cases seen in a municipal court or a mental health center's crisis department are identical. The concepts used to describe these common cases and the resultant agency actions taken differ drastically between the legal and mental health arenas. This paper presents a working model that combines mental health and legal concepts and personnel to deal effectively with this overlapping body of problems. The model provides for crisis intervention for the clients, preventive education for young attorneys, and system change in the criminal justice system.

Community Mental Health Services↗
PubMed1979

67Gallium uptake in psittacosis infection.

67Gallium citrate isotope scanning was performed in a febrile patient with pneumonitis and hepatitis who was later shown to have psittacosis. Focal isotope uptake was detected in both lungs in the absence of radiological changes. There was no enhanced concentration in the liver where inflammatory cell infiltration was slight.

Female↗
PubMed1979

A study of synovial fluid and cytology in arthritis associated with herpes zoster.

A case of herpes zoster complicated by acute arthritis with effusions is described. The white cell count in the synovial fluid was low, with a predominance of neutrophils. The synovium showed superficial deposits of fibrin, slight intimal hyperplasia, and subintimal polymorph infiltration. Varicella virus was not detected by culture or electron microscopy, but varicella antigen was demonstrated in the cytoplasm of macrophages in the effusion. Other findings did not determine whether the antigen had appeared in the joint from circulating immune complexes, or following synovial phagocytosis or proliferation of virus.

Aged↗
PubMed1979

Patterns of induced variation in the morphology, hyaluronic acid secretion, and lysosomal enzyme activity of cultured human synovial cells.

In contrast with newly isolated cells or early primary cultures, synovial cell lines in standardised growth conditions assume a rather uniform fibroblast-like appearance. However, 2 distinct variations in the cytological pattern can be induced at this stage. The first is characterised primarily by increased numbers of small phase-dense organelles that show the distinctive fluorescence of lysosomes after supravital staining, and are interspersed with vacuoles. The associated functional changes include increased enzyme activity and decreased net synthesis of hyaluronic acid. This variation can be induced by exposure to indigestible neutral sugars, adenosine, or its 5' nucleotides. The second variation consists of a striking reorganisation of cytoplasm by condensation into dense ridges or a dendritic network of processes. It is accompanied by increased hyaluronic acid secretion and is induced by agents that enhance intracellular activity of cyclic adenosine monophosphate, such as dibutyryl cyclic adenosine monophosphate and cholera enterotoxin. It appears possible to direct differentiation in synovial cell lines to correspond at least in part with the presumed functions of the different cell types in the parent tissue. The 2 patterns may be useful markers to correlate with other aspects of synovial cell function in vitro.

Acetylglucosaminidase↗
PubMed1979

Effects of carrageenin on human synovial cells in vitro: morphology, hyaluronic acid production, growth, and the lysosomal system.

Some in-vitro effects of the arthritogenic polysaccharide carrageenin were studied on cells from human synovium. Synovial cells were isolated from intact human knee joints, and cell lines were developed by passaging with trypsin. Carrageenin was ingested by the cells but did not significantly affect cell growth, numbers of lysosomes, intracellular lysosomal enzyme activity (N-acetyl-beta-D-glucosaminidase), or release of lysosomal enzyme from cells. Carrageenin produced a reduction in net hyaluronic acid synthesis. It also induced a striking morphological change in a high proportion of synovial cells, characterised by increased spreading over the culture surface and apparent condensation of the cytoplasm into a pattern of ridges. Nonrheumatoid and rheumatoid synovial cells behaved similarly to one another.

Acetylglucosaminidase↗
PubMed1978

Effect of blood pH on anionic ferritin transport through rat aortic endothelium.

Acute lowering of blood pH between 7.4 and 6.9 in rats by ventilation with 10 or 20% CO2 does not increase the passage of ferritin molecules across the aortic endothelium. These results do not rule out alteration of endothelial permeability to anionic macromolecules in local circulatory disturbances when blood pH drops to levels much lower than 6.9.

Animals↗