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M E Roberts

Publications and source records attributed to M E Roberts.

32 records · Page 2Linked to original sources

Comparative study of pure-tone, impedance, and otoscopic hearing screening methods. A survey of native Indian children in British Columbia.

A survey of 1,109 native Indian children in five communities in British Columbia was conducted to determine incidence of middle ear pathologic features and to compare impedance and pure-tone audiometry as hearing screening methods. Survey teams included a public health nurse, two otologists, and two audiologists. On ear, nose, and throat (ENT) otoscopic examination, the incidence of middle ear disease requiring treatment was 12%. Disease was most prevalent in the preschool- and primary school-aged children. Pure-tone audiometry yielded 62% normal and 19% abnormal results. Nineteen percent of the children could not be tested by this method. Impedance audiometry yielded 54% normal and 38% abnormal results on the stringent criteria used to define the parameters of normality. Eight percent of the children could not be tested. Since there was a high incidence of middle ear pathologic features in the preschool group of children who could not be successfully evaluated by pure-tone audiometry, it is suggested that further investigation of impedance audiometry be undertaken in order to define parameters that will provide the most reliable referral criteria.

Adolescent↗

Psoriatic arthritis. Follow-up study.

227 patients with psoriasis and various forms of arthritis have been kept under review. Psoriasis and inflammatory arthropathy was present in 168 patients, of whom 94 have been followed up for more than 10 years. An arthritis indistinguishable from rheumatoid disease was present in 78%, distal joint arthritis in 16-6%, and deforming arthritis in 4-8%. There was a female predominance in the sex ratio of patients, although males predominated in the distal joint group (male:female 1-5:1). The peak age of onset was between 36 and 45 years, although in the deforming group the arthritis began before the age of 20 three times as commonly as it did in the indistinguishable group. Onset was acute in nearly half of the patients. At onset the distal joints were affected in one-third of the distal joint group. A synchronous onset of skin and joint changes was uncommon. Skin lesions usually preceded the arthritis but occurred after onset in 16%. Apart from in the deforming group, the arthritis was mild, judged by the number of admissions to hospital for treatment of the joint disease, and the time off work. Deterioration clinically and radiographically occurred in only a small portion of the distal joint and indistinguishable groups. Antimalarial drugs have been used in 7 patients, with deterioration of the skin condition in 4. Uveitis occurred particularly in the men of all three groups, but was most frequent in those with deforming arthritis. A family history of psoriasis was obtained in 26% of first-degree relatives and 13% of second-degree relatives. A history of polyarthritis was most common in patients in the deforming group. The sheep cell agglutination test was negative in the majority, but was positive in 16% of the indistinguishable group, fluctuating in a further 10%. A small number of joints only deteriorated radiographically (10% of the distal and indistinguishable groups). The men in the distal group showed greater radiographic changes and more deterioration in the terminal interphalangeal joints of the fingers than the women. Similarly they showed more deterioration of the metatarsophalangeal joints than the women. 18 patients died, one with gastric haemorrhage resulting from treatment of exfoliative psoriasis with immunosuppressive therapy, and 2 from bronchopneumonia thought to be related to immobility caused by the arthritis.

Adult↗

Automated instrument for the fluorescent treponemal antibody-absorption test and other immunofluorescence tests.

An automated diagnostic test instrument and its development program are described. The instrument automates the fluorescent treponemal antibody-absorption test for syphilis to the extent that only 4 hr of technician time is required to conduct approximately 200 tests daily. Evaluation to date suggests its efficacy. In addition, preliminary studies indicate the feasibility of detecting antibodies to Toxoplasma gondii, Plasmodium malariae, and nucleoprotein (antinuclear factor). The instrument would seem to have broad application for routine and research immunofluorescence testing. Two elements comprise the instrument: a slide processor and a microscope attachment. The slide processor is an electro-pneumatically actuated device which automatically feeds special laboratory slides, on which antigen or other reagents are prefixed, through a series of operations which provide reagent application, incubation, washing, drying, and stacking of the finished slides for readout. The instrument provides flexibility in that incubation time and temperature as well as point, sequence, and duration of reagent application can be varied to accommodate a variety of immunofluorescence techniques. The microscope attachment can be fitted to all conventional dark-field fluorescence microscopes and makes possible the reading of three to six slides per minute. The reacted slides from the processor are injected sequentially onto the stage of the microscope by movement of a lever. As injected, slides are automatically in visual focus; fine focus is occasionally required. Scanning of the reacted field is accomplished by means of the normal microscope controls. A buffered glycerol coupling is maintained between the darkfield condenser substage lens and the slide cover glass by means of a pushbutton-actuated feed system.

Absorption↗

Reduction of nonspecific background staining in the fluorescent treponemal antibody-absorption test.

The nonspecific background fluorescence which occurs with the fluorescent treponemal antibody-absorption test for syphilis was found to result from a reaction between serum-treated Treponema pallidum organisms and the conjugated antihuman gamma-globulin. It was also shown that beta-lipoprotein and albumin were the important contributing factors in human serum. Various dilutions of 2.5% trypsin in phosphate-buffered saline specifically reduced background fluorescence under proper test conditions. By employing a trypsin digestion method, a semiautomated procedure utilizing a visual readout has been postulated as feasible.

Antibodies, Anti-Idiotypic↗

Shelf life of fluorescent treponemal antibody-absorption test reagents.

Properly prepared, standarized, and stored fluorescent treponemal antibody-absorption (FTA-ABS) reagents have been shown to have stabilities equal to other biological reagents. A liquid antigen over 10 years old has been shown to give a satisfactory reaction. Newer preparations have now been shown to be stable for over 5 years, and the tests on each are being continued. The very new liquid antigens which were originally standardized by the FTA-ABS method have shown no decrease in potency over a 20-month period. Stability studies on antigens dried on slides are now in their eighth month, with no apparent loss in potency. The stability of the conjugate is constant when stored frozen at -20 C or lyophilized. When stored as a liquid at 4 C, the stability is governed by the pH and the molarity of the buffer. The standardized and lyophilized sorbent has been shown to be stable for over 1 year.

Antigens↗