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Biomedical subjects

A Quinn

Publications and source records attributed to A Quinn.

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

Antibodies directed against neutrophils (C-ANCA and P-ANCA) are of distinct diagnostic value in systemic vasculitis.

In a prospective study, sera from over 700 patients with suspected vasculitis, including over 200 patients undergoing renal biopsy, were examined for antibodies to neutrophil cytoplasmic antigen (ANCA). An indirect immunofluorescence assay on ethanol fixed human neutrophils identified two types of autoantibody: C-ANCA, which produces diffuse cytoplasmic staining and P-ANCA, which produces an artefactual nuclear/perinuclear staining pattern. The diagnosis of patients in whom ANCA of either form was found was established following case note review according to defined diagnostic criteria. Forty of 45 patients whose sera contained C-ANCA at a titre of greater than or equal to 1/40 satisfied the diagnostic criteria for Wegener's granulomatosis or microscopic polyarteritis. Twelve of 30 patients with P-ANCA at a titre of greater than or equal to 1/40 were also classified as having one of these disorders. Seventeen of the remaining 18 patients had immune-mediated disorders with deep organ damage. Of 47 ANCA-positive patients who underwent renal biopsy, 21 had glomerulonephritis associated with Wegener's glomerulonephritis and a further 22 had a necrotizing or crescentic glomerulonephritis. Ethanol fixation is important for discrimination of C-ANCA and P-ANCA. C-ANCA are highly specific for Wegener's granulomatosis and microscopic polyarteritis. In patients undergoing renal biopsy, the presence of these antibodies is highly specific for a necrotizing or crescentic glomerulonephritis.

Arteritis↗
PubMed1989

Brain tumour mortality in immigrants.

All Canadian deaths due to malignant brain tumour for the years 1970-73 were identified and analysed for country of birth. The years 1970-73 were chosen since in later years country of birth was no longer available for each death. The brain tumour population consisted of 1551 male and 1058 female deaths and matched controls were chosen from deaths due to other causes. Americans who died of brain tumour in Canada had a standardized mortality ratio (SMR) of 1.0 compared to their fellow Americans in the USA. Italian, German, Dutch and British immigrants had SMR between 1.5 and 2.6 compared to rates in their home countries and between 1.24 and 2.09 when compared to Canadian rates. A series of graphs shows the increased risk for male immigrants quite dramatically, and indicates that for females the increases were less pronounced. Further analysis showed that the excess risk is confined to those who were born in Western Europe while their Canadian-born children experienced the same rates as all Canadians. Based on the limited information available, occupation could not be shown to play a role in establishing risk. An attempt was made to pinpoint the years of immigration which showed the greatest risk. It is concluded that the determination of risk of brain tumour has a strong environmental component. The possibilities for identification of this component are discussed.

Adult↗
PubMed1988

An ELISA for the detection of anti-acetylcholine receptor antibodies using biotinylated alpha-bungarotoxin.

An antibody-capture enzyme immunoassay has been developed for the detection of anti-acetylcholine receptor (AChR) antibodies in tissue culture supernatants using biotinylated alpha-bungarotoxin (B alpha BGT). Immunoglobulins in culture supernatants were bound indirectly to microtitre plates via an anti-globulin antibody already coupled to polyvinyl plates. Anti-AChR antibodies were then detected by incubation with AChR crude extract. Bound AChR was revealed by incubation with B alpha BGT followed by horseradish peroxidase-conjugated avidin. This assay is specific, more sensitive than the commonly used double antibody radioimmunoassay, avoids the use of radioactive material, is practical for large numbers of samples and is particularly suitable for detecting anti-AChR antibodies in tissue culture supernatants.

Animals↗
PubMed1987

Noninvasive continuous blood pressure measurement from the finger: optimal measurement conditions and factors affecting reliability.

We recorded finger arterial blood pressure (FINAP) in 50 male patients during various types of surgical operations. Three different types of cuffs were used on four fingers of each patient. Measurements were made by the arterial volume-clamp method of Penaz. The FINAP measurements were compared with pressure data obtained ipsilaterally from a radial artery catheter-transducer system (intraarterial pressure [IAP]) to find optimal recording conditions and to document factors affecting FINAP readings. The thumb, with a specially designed cuff, gave the most accurate results. The mean FINAP - IAP difference for the thumb was -4.8 mm Hg for systolic pressure, 1.49 mm Hg for diastolic pressure, and 0.29 mm Hg for mean pressure. The differences were statistically significant for systolic and diastolic pressure but not for mean pressure. The regression slope for thumb systolic FINAP/IAP was 0.979, that for thumb diastolic FINAP/IAP was 0.963, and that for mean thumb FINAP/IAP was 0.996, whereas the intercepts were 7.499 for systolic pressure, 0.802 for diastolic pressure, and 0.083 for mean pressure. The correlation coefficients were 0.945 (systolic), 0.884 (diastolic), and 0.949 (mean). The correlation coefficients with the other fingers ranged from 0.502 to 0.922 for systolic pressure, 0.757 to 0.932 for diastolic pressure, and 0.767 to 0.892 for mean pressure. The slopes for the various finger-cuff combinations ranged from 0.537 to 0.996, and the intercepts ranged from 0.083 to 32.387 from mean pressure. In 3 patients (6%) the FINAP measurement was not possible because of insufficient peripheral circulation. In 9 other patients (18%) the FINAP measurements were not accurate during some periods of time.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Concentrations of antibodies in paired maternal and infant sera: relationship to IgG subclass.

Previous studies comparing IgG subclass concentrations in cord and maternal sera have indicated that IgG1 is transported across the placenta to a greater extent than is IgG2. The purpose of our study was to examine the relationship between the transport of IgG1 and IgG2 and the transport of specific antibodies that are relatively restricted to a particular subclass, either IgG1 or IgG2. The concentrations of total serum IgG1 and IgG2 and those of IgG-anti-tetanus toxoid (TT) and anti-group A streptococcal carbohydrate (GAC) were measured in 30 paired maternal and cord sera. Previous studies have shown that anti-TT in adults is predominantly IgG1, whereas anti-GAC is predominantly IgG2. The mean cord/maternal concentration ratios of IgG1 and anti-TT were similar (1.77 +/- 0.56 and 1.93 +/- 0.67, respectively), but differed significantly (P = 0.0001) from those of IgG2 and anti-GAC (0.99 +/- 0.39 and 1.01 +/- 0.45, respectively). We confirmed the difference in cord/maternal concentration ratios of IgG1 and IgG2 antibodies by measuring IgG1 and IgG2 antibodies specific for Haemophilus influenzae type b capsular polysaccharide; the mean cord/maternal concentration ratio of IgG1-anti-Hib PS was significantly higher than that of IgG2-anti-Hib PS (2.23 +/- 0.83 compared with 0.94 +/- 0.49, P = 0.01). These results indicate that placental transport of IgG antibodies is related to their subclass composition.

Adult↗
PubMed1986

Health concerns and health-related behaviours of adolescents.

Health promotion and treatment programs for adolescents must be tailored to the unique concerns and needs of this population. A questionnaire was mailed to 1000 adolescents aged 12 to 20 years in the Ottawa-Carleton region; 729 responded, giving information on their health concerns and habits. The teenagers reported worrying mostly about chronic conditions such as acne, menstrual disorders, emotional problems, dental problems and being overweight. Some of these conditions can be treated if care is sought. The psychosocial problems most important to the adolescents were school and family problems. Girls tended to report health concerns more often than boys, but there was little variation by age or social group. Although the proportions of adolescents who were smoking cigarettes, drinking alcoholic beverages or using "recreational" drugs or who had ever had sexual intercourse were relatively high, the number of respondents who perceived such habits as health problems was low. There was a low level of concern about birth control among the respondents, including those who indicated that they had had sexual intercourse. The fact that significantly more girls than boys reported that they smoked and had engaged in sexual intercourse suggests specific targets for health promotion activities.

Adolescent↗
PubMed1986

Adolescent health needs. II: Utilization of health care by adolescents.

In a random, mailed survey, 730 adolescents supplied information on their patterns and preferences for health care. The majority of respondents reported that they usually receive medical care from a private physician. Girls consulted physicians more frequently than boys, but there was no significant variation by age or social group. As the age of the respondent increased, the proportion visiting pediatricians decreased. When asked what they liked and disliked about their physician, respondents placed great emphasis upon the personal characteristics of the practitioner. Long waiting periods were the most common complaint. A significant proportion of adolescents with health concerns do not consult a health professional, even in cases where efficacious treatment may be available. Nervous/emotional problems, obesity, and birth control are concerns of adolescents which should be discussed with health professionals.

Adolescent↗
PubMed1984

Measurement of urinary leukocyte esterase activity: a screening test for urinary tract infections.

We evaluated the efficacy of testing for the presence of esterase (an enzyme released only from leukocytes) in the urine as an indicator of the presence of pyuria. We hypothesized that a "dipstick" test for urinary leukocyte esterase activity would be a rapid and simple screening technique for detecting urinary tract infections (UTI). To test our hypothesis we collected fresh urine specimens from 203 patients (148 outpatients, 55 inpatients) with a suspected UTI. Each specimen was divided into three aliquots; one was used for reagent strip testing (for leukocyte esterase, nitrite, and blood), one for microscopy, and one for culture. Of the 203 specimens, 49 showed significant bacteriuria (greater than or equal to 10(5) organisms/mL). The leukocyte esterase test was 100% sensitive (0% false negatives) with a 76% specificity (24% false positives) in predicting significant bacteriuria. Although a positive nitrite reaction was more specific (99% specificity, 0.6% false positives), it was insensitive (27% sensitivity, 73% false negatives). The high sensitivity of reagent strip leukocyte esterase testing for pyuria makes it a valuable screening test that should lead to the elimination of many needless urine cultures and microscopic examinations.

Adult↗
PubMed1984

Tumorigenicity in athymic mice of the human colon carcinoma cell line SW1116 expressing the tumor-associated antigenic determinant CA 19-9.

The human colorectal carcinoma cell line SW1116 under optimal growth conditions synthesized and shed antigens bearing the monoclonal antibody-defined carbohydrate determinant CA 19-9. Antigen expressing CA 19-9 in cell culture supernatant was quantitated by an immunoradiometric assay for CA 19-9. Injection of SW1116 cells s.c. into athymic BALB/c mice resulted in the growth of moderately differentiated tumors possessing a distinct morphological resemblance to a typical adenocarcinoma of the colon. Intervals to tumor appearance were dependent on inoculum dose, but 95% of mice at both 5 X 10(6) and 10(7) cells/mouse developed tumors within 14 to 21 days. CA 19-9 antigen was detected in the sera of all nude mice with SW1116 tumors, and antigen concentration correlated (r = 0.77) with tumor volume throughout the 9-week study. The half-life of this antigen in serum following tumor excision from nude mice was 6.5 +/- 1.5 (S.D.) hr. Carcinoembryonic antigen was also detected in serum from mice bearing SW1116 tumors by an immunoradiometric assay for carcinoembryonic antigen, but its concentration correlated (r = 0.86) with tumor volume for only the first 4 weeks of tumor growth. Significant levels of endogenous immunoglobulin G1 and immunoglobulin G3 antibodies to CA 19-9 antigen were found in the serum of nude mice with SW1116 tumors by radioimmunodiffusion, but no apparent relationship between antibody titer and tumor growth or CA 19-9 antigen level in serum was evident. This tumor model may be useful in devising radioimmunodetection and immunotherapeutic strategies for primary and metastatic human colon carcinomas.

Animals↗
PubMedDate not supplied

Data mining in child welfare.

Data mining is the sifting through of voluminous data to extract knowledge for decision making. This article illustrates the context, concepts, processes, techniques, and tools of data mining, using statistical and neural network analyses on a dataset concerning employee turnover. The resulting models and their predictive capability, advantages and disadvantages, and implications for decision support are highlighted.

Child↗
PubMedDate not supplied

Adolescents at risk.

Explore the source record for details and available documents.

Adolescent↗