Occupational sensitization to laboratory animals.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to S Gordon.
Explore the source record for details and available documents.
A two-part study was conducted with sport physiotherapists to examine their perceptions of both frequency and significance of emotions and behaviours displayed by injured athletes during treatment, and the importance of psychological skills in rehabilitation. A questionnaire, developed from a preliminary study (Part 1) with experienced sport physiotherapists (N = 10), was mailed to 500 sport physiotherapists in Australia, New Zealand and Canada (Part 2). Responses from Australian (N = 147), New Zealand (N = 65) and Canadian (N = 45) subjects suggested that: (i) anxiety and frustration is experienced frequently by injured athletes, and non-compliance to the rehabilitation program is a significant problem preventing effective recovery and rehabilitation; (ii) psychological skills training and learning to deal with psychological responses to injury would facilitate more effective treatment; and (iii) athlete self-presentation styles influence the support and attention received from physiotherapists. Results are discussed in relation to previous research and recommendations for improving both the art (applied skills) and science (theoretical content) of professional training programs for sport physiotherapists are provided.
OBJECTIVES: Evidence is now accumulating that the prevalence of allergy to laboratory animals is related to the intensity of exposure to animal allergens. Whilst airborne animal allergen concentrations may be influenced by the litter type, cage design and stock density, the effectiveness of methods to reduce personal exposure has not been objectively assessed. METHODS: Air samples were collected at 2 L/min and 180 L/min onto polytetrafluoroethylene (PTFE) filters and the rat urinary aeroallergen (RUA) and mouse urinary aeroallergen (MUA) concentrations were measured by radioallergosorbent test (RAST) inhibition. RESULTS: When 545 mice (11.l mice/m3) were housed in ventilated cages (Thoren Maximiser cage system) operated at positive pressure to the environment, the static MUA concentration (n = 24, median = 0.10 microg/m3) was reduced sevenfold when compared with conventional cage systems (n = 12, median =0.67 microg/m3, P< 0.001). MUA could be further reduced if the ventilated cage system was operated at lower pressure; static samples (n = 1) collected at 180 L/min at negative, ambient and positive pressure registered < 0.003, 0.02 and 0.28 microg/m3, respectively. During cleaning out, the intensity of personal exposure to RUA was apparently reduced twofold when soiled litter was removed by vacuum (n = 17, median = 22.87 microg/m3) when compared with tipping (n = 18, median = 38.15 microg/m3), P = 0.002) although the task took twice as long to perform. The RUA exposure associated with handling rats was'reduced 25-fold when performed in a ventilated cabinet (n = 21, median = 2.67 microg/m3) compared with handling of rats on an open bench (n = 17, median = 54.39 microg/m3, P = 0.0001). CONCLUSIONS: Effective reduction of exposure to animal allergens can now be achieved by the use of ventilated systems both for housing and handling rats and mice providing safety equipment is used correctly. The vacuum removal of soiled litter during the task of cleaning out was less efficient and additional respiratory protection is therefore recommended for this procedure.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
BACKGROUND: Mouse and rat urinary proteins are potent occupational allergens for exposed personnel. Methods of measuring airborne allergens differ greatly, and reported levels of allergens vary considerably between laboratories. OBJECTIVES: To compare the values obtained using two different methods of allergen detection. METHODS: Air samples were collected in rat rooms in Sweden and the United Kingdom at 2 L/min on to polytetrafluoroethylene (PTFE) filters and extracted in buffer containing 0.5% v/v Tween 20. Airborne rat urinary allergen (RUA) was measured in all samples by both RAST inhibition using a polyclonal human serum pool (UK) and a two monoclonal antibody sandwich ELISA employing antibodies specific for Rat n 1.02 (alpha2u-globulin) (Sweden). RESULTS: The two methods gave values which were correlated (r2 log values = 0.72, P<0.0001), but differed by several orders of magnitude (median [range] ratio of RAST inhibition/ELISA = 316 [7-26(80)]. There was a systematic bias: as the absolute values increased, the difference in the measurements increased. The rat urine standards used were antigenically similar. CONCLUSIONS: A large contrast in RUA values obtained from the two assays was observed in this study. This may be primarily due to methodological differences, but variations in antibody specificities or composition of allergenic epitopes in the air samples may contribute. The results demonstrate that standardization of methods and antibodies is necessary before interlaboratory comparisons can be made.
There is increasing awareness of the importance of psychopathological and behavioral changes in dementia and a need for a technique to measure these noncognitive features. Such a schedule should keep screening questions to a minimum, include a severity measure, exclude symptoms resulting from physical illness, be as brief as possible, and not mix domains of psychopathology. To test the reliability, sensitivity, and validity of a newly developed test, 30 carers were interviewed four times during 6 weeks. An obligatory stem question in each category was followed by supplementary questions. The interviewer recorded the presence of each symptom, its severity, when each symptom started, its duration, and whether it was still present. To detect the presence of delusions, the informant was asked about the patient's insight. Satisfactory differences in mean kappa values were demonstrated in test-retest and interrater reliability and validity compared with other techniques. This test may be useful to measure the outcome of drug trials, for correlating psychopathological and behavioral changes with autopsy findings and in epidemiological surveys.
The synthesis of a series of 2-amino-4-hydroxy-delta-valerolactam derivatives is described (compounds 4 to 10). These compounds showed a high anthelmintic in vitro activity against the Nippostrongylus brasiliensis model.
Explore the source record for details and available documents.
Ligands for the cysteine-rich (CR) domain of the mannose receptor (MR) were detected by incubating murine tissues with a chimeric protein containing CR fused to the Fc region of human IgG1 (CR-Fc). In naive mice, CR-Fc bound to sialoadhesin+, F4/80low/-, macrosialin+ macrophages (M phi) in spleen marginal zone (metallophilic M phi) and lymph node subcapsular sinus. Labeling was also observed in B cell areas of splenic white pulp. Western blotting analysis of spleen and lymph nodes lysates revealed a restricted number of molecules that interacted specifically with CR-Fc. In immunized mice, labeling was upregulated on germinal centers in splenic white pulp and follicular areas of lymph nodes. Kinetic analysis of the pattern of CR-Fc labeling in lymph nodes during a secondary immune response to ovalbumin showed that CR ligand expression migrated towards B cell areas, associated with cells displaying distinctive dendritic morphology, and accumulated in developing germinal centers. These studies suggest that MR+ cells or MR-carbohydrate-containing antigen complexes could be directed towards areas where humoral immune responses take place, through the interaction of the MR CR domain with molecules expressed in specialized macrophage populations and antigen transporting cells.
Numerous immature thymocytes undergo apoptosis and are rapidly engulfed by phagocytic thymic macrophages. The macrophage surface receptors involved in apoptotic thymocyte recognition are unknown. We have examined the role of the class A macrophage scavenger receptor (SR-A) in the engulfment of apoptotic thymocytes. Uptake of steroid-treated apoptotic thymocytes by thymic and inflammatory-elicited SR-A positive macrophages is partially inhibited by an anti-SR-A mAb and more completely by a range of scavenger receptor ligands. Thymic macrophages from mice with targeted disruption of the SR-A gene show a 50% reduction in phagocytosis of apoptotic thymocytes in vitro. These data suggest that SR-A may play a role in the clearance of dying cells in the thymus.
Explore the source record for details and available documents.
Inactivation of HIV-1 contaminated materials or biological samples is of great importance and requires the use of a reliable assay to detect residual infectivity. In this study we treated cell-free or cell-associated (monocyte-derived macrophages) HIV-1 with two chemicals known for their antiviral activities, beta-propiolactone (beta PL) and formaldehyde (FO), and tested it for the presence of residual infectivity. HIV-1 infected primary monocyte-derived macrophages (MDM) or cell-free HIV-1 were fixed with increasing concentrations of either beta PL or FO for 1 day at 4 degrees C. Then either fresh primary MDM or fresh medium was added, and the supernatant p24 levels were assayed up to 12 days after infection. All the supernatants harvested were added to indicator cells, fresh primary MDM, to assess for residual infectivity. The results show that p24 measurement is not a reliable assay for the detection of residual infectious virions after chemical fixation of HIV-infected primary MDM. In contrast, the use of indicator primary cells (MDM) is a much more sensitive and reliable assay. By performing an indicator cell assay we showed that FO efficiently inactivates cell-associated and cell-free HIV-1 at concentrations as low as 1% v/v. In contrast beta PL is more efficient in inactivating cell-free than cell-associated virus and does not inactivate cell-associated HIV-1 at concentrations as high as 1% v/v.
The transport of solutes between blood and brain is regulated by a specific barrier. Capillary endothelial cells of brain are known to mediate barrier function and facilitate transport. Here we report that specific cells surrounding arterioles, known as Mato's fluorescent granular perithelial (FGP) cells or perivascular microglial cells, contribute to the barrier function. Immunohistochemical and in situ hybridization studies indicate that, in normal brain cortex, type I and type II macrophage scavenger receptors are expressed only in FGP/perivascular microglial cells, and surface markers of macrophage lineage are also detected on them. These cells mediate the uptake of macromolecules, including modified low density lipoprotein, horseradish peroxidase, and ferritin injected either into the blood or into the cerebral ventricles. Accumulation of scavenged materials with aging or after the administration of a high-fat diet results in the formation of honeycomb-like foam cells and the narrowing of the lumen of arterioles in the brain cortex. These results indicate involvement of FGP/perivascular microglial cells in the barrier and scavenger functions in the central nervous system.
Explore the source record for details and available documents.
The 5' region of the human lysozyme gene from -3500 to +25 was fused to a chloramphenicol acetyltransferase (CAT) reporter gene and three transgenic founder mice were obtained. All three transgenic lines showed the same pattern of CAT enzyme expression in adult mouse tissues that was consistent with the targeting of elicited, activated macrophages in tissues and developing and elicited granulocytes. In normal mice high CAT enzyme activity was found in the spleen, lung, and thymus, tissues rich in phagocytically active cells, but not in many other tissues, such as the gut and muscle, which contain resident macrophages. Cultured resident peritoneal macrophages and cells elicited 18 hr (granulocytes) and 4 days (macrophages) after injection of sterile thioglycollate broth expressed CAT activity. Bacillus Calmette-Guérin infection of transgenic mice resulted in CAT enzyme expression in the liver, which contained macrophage-rich granulomas, whereas the liver of uninfected mice did not have any detectable CAT enzyme activity. Although the Paneth cells of the small intestine in both human and mouse produce lysozyme, the CAT gene, under the control of the human lysozyme promoter, was not expressed in the mouse small intestine. These results indicate that the human lysozyme promoter region may be used to direct expression of genes to activated mouse myeloid cells.