Biomedical subjects

P Qvist

Publications and source records attributed to P Qvist.

12 recordsLinked to original sources

PubMed1995

Applications of an enzyme immunoassay for a new marker of bone resorption (CrossLaps): follow-up on hormone replacement therapy and osteoporosis risk assessment.

An enzyme-linked immunosorbent immunoassay (ELISA) for a new marker of bone resorption (CrossLaps) was evaluated. The ELISA procedure determines degradation products of type I collagen in urine. Values obtained in the ELISA and in pyridinoline by high pressure liquid chromatography were correlated after a correction for creatinine. A high correlation was found (r = 0.77; n = 81). A group of postmenopausal women (n = 180) showed an increase of more than 70% compared to values in premenopausal women (n = 104). Hydroxyproline was increased by 23%, osteocalcin by 52%, pyridinoline by 31%, and deoxypyridinoline by 50%. A highly significant decrease (60.7%) in the CrossLaps values was seen after 12 months in samples from patients receiving hormone replacement therapy compared to a placebo group. The spontaneous bone loss in an untreated group of women was determined by repeated forearm bone mass measurement over 24 months. Baseline values obtained in the CrossLaps ELISA were correlated to the rate of loss, yielding a highly significant r value of -0.61, indicating that CrossLaps might be a useful parameter for assessment of the risk of osteoporosis in postmenopausal women.

Amino Acid Sequence↗

PubMed1995

Measurement of a more stable region of osteocalcin in serum by ELISA with two monoclonal antibodies.

Intact human osteocalcin purified from femoral bones as well as tryptic fragments of the intact molecule [amino acids (aa) 1-19, 20-43, and 45-49] were used to raise and screen monoclonal antibodies (MAbs). A two-site ELISA for measurement of human osteocalcin in serum was developed with use of these MAbs. A MAb recognizing midregion human osteocalcin (aa20-43) was used as capture antibody, and an NH2 terminus (aa7-19)-specific peroxidase-conjugated MAb was used for detection. Human osteocalcin obtained from bone was used for calibration, and parallelism was observed for osteocalcin from serum samples, NH2-terminal midfragments (aa1-43), and synthetic human osteocalcin. Both inter- and intraassay variations were < 7%. Serum osteocalcin in healthy premenopausal women (n = 49) was 18.3 +/- 4.2 micrograms/L (mean +/- SD) and 28.6 +/- 9.7 micrograms/L in early postmenopausal women (n = 114). The mean serum concentration (n = 10) decreased by 10% after 7 days of storage at 4 degrees C, whereas the concentration of intact human osteocalcin was reduced 63%. The N-MID ELISA and an IRMA measuring intact human osteocalcin were used to monitor the effect of hormone replacement therapy in a retrospective study. A significant decrease to the premenopausal concentration was detected only in the N-MID ELISA.

Antibodies, Monoclonal↗

PubMed1994

Endoscopic treatment and restrictive surgical policy in the management of peptic ulcer bleeding. Five years' experience in a central hospital.

BACKGROUND: Despite improved surgical and endoscopic technics, acute bleeding from peptic ulcer is still a serious condition, and management remains controversial. The aim of the study was to evaluate a management policy of aggressive endoscopic and restrictive surgical treatment for acute peptic ulcer bleeding. METHODS: We retrospectively investigated the course of all 341 hospital admissions during 1986 to 1990 caused by bleeding peptic ulceration from the first bleeding episode until 30 days after discharge. RESULTS: Total mortality, in-hospital 30 days' mortality, and operative mortality were 6.3%, 4.4%, and 23.5%, respectively. Risk factors associated with mortality were age and number of concomitant diseases, malignant disease, rebleeding episodes, and surgical complications. No patients without associated illness died. In 73 cases (21%) patients were treated endoscopically one or more times, and altogether 17 patients (5%) were operated on. Rebleeding occurred in 67 cases (23%), and only 23 of these were treated endoscopically at admission. Twenty-six (51%) of the rebleeding patients were treated endoscopically and 13 rebleeding patients were operated on. Two-thirds of patients presenting with arterial bleeding were managed endoscopically. No complications occurred in endoscopically treated patients, whereas there were complications in 8 of 17 operated patients. Operated patients needed significantly more intensive care unit observation time and had longer hospital stay than patients treated endoscopically. CONCLUSIONS: Endoscopic treatment is a safe procedure with a low mortality, and, if successful, the need for emergency surgery is substantially reduced. In the relatively few patients requiring surgery after unsuccessful endoscopy, the mortality remains high.

Acute Disease↗

PubMed1994

Immunoassay for quantifying type I collagen degradation products in urine evaluated.

An enzyme-linked immunosorbent assay (ELISA) for measuring type I collagen degradation products in urine < 3 h was evaluated. The measuring range was 0.5-10.5 mg/L with a detection limit of 0.2 mg/L. Within-run and total CVs were 5.3% and 6.6%, respectively. Analytical recovery averaged 100%. The mean (+/- SD) concentrations in urine samples from a healthy premenopausal population (n = 102) were 250 +/- 110 mg/mol creatinine (Cr). A group of healthy postmenopausal women (n = 410) gave a mean value of 416 +/- 189 mg/mol Cr. Values obtained in the ELISA correlated well (r = 0.83) to HPLC values for the established bone resorption marker deoxypyridinoline (n = 214), slightly better than the correlation to hydroxyproline measurements (r = 0.78, n = 421). We conclude that the assay described here presents a useful tool for further elucidating the importance of type I collagen degradation products in urine.

Amino Acid Sequence↗

PubMed1994

A simple enzyme-linked immunosorbent assay of human osteocalcin.

A heterologous ELISA for measurement of osteocalcin (bone Gla-protein) is described, involving biotinylated bovine osteocalcin and polyclonal antibodies. The log-linear range was 2.3-37.5 micrograms/L. Between-run (total) and within-run CVs (n = 10) were 5.7-6.4 and 5.9-6.1%, respectively; analytical recoveries ranged from 92% to 108%. Comparison of our method (x) with an RIA (y) yielded y = 1.10 x -0.01 microgram/L, Sylx = 1.4 micrograms/L, r = 0.958 (n = 167). Serum osteocalcin in healthy premenopausal women (n = 29) was 8.7 +/- 3.3 micrograms/L (mean +/- SD) and 11.8 +/- 4.5 micrograms/L in early-postmenopausal women (n = 24). The assay was evaluated in a double-blind placebo-controlled study of healthy early-postmenopausal women, treated for 12 months with either (a) estrogen valerate plus medroxyprogesterone acetate (n = 18), (b) 17 beta-estradiol and desogestrel (n = 22), or (c) placebo (n = 17). Serum osteocalcin decreased significantly (P < 0.001) with either therapy, but increased (P < 0.05) with placebo.

Biotin↗

PubMed1993

[Open access upper endoscopy. Can the practice be improved?].

150 patients who were referred to the open access endoscopical unit in a county hospital for upper gastrointestinal examination were evaluated. The aim was to answer the following questions: How often is this upper GI-endoscopy of value for medical treatment of the patient, and is "open access endoscopy" a practical system? In order to obtain a more reliable diagnosis it is necessary to examine the patient without delay, and thereby avoid the masking effect of H-2 blockers and omeprazole. More attention to anamnestic risk factors would improve case selection. In many cases it is possible to rely on X-ray examination, and thus reduce the burden on the endoscopy unit and allow for instant endoscopy service.

Adult↗

PubMed1992

A monoclonal blocking ELISA detecting serum antibodies to Mycoplasma hyopneumoniae.

A monoclonal blocking enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to Mycoplasma hyopneumoniae in porcine serum has been developed. The monoclonal antibody (mAb) reacts with an M. hyopneumoniae specific epitope on a molecule of approximately 74 kDa. Only sera from M. hyopneumoniae infected pigs were able to block the binding of the mAb although antibodies from M. flocculare infected pigs also recognized a 74 kDa molecule. Sera from experimentally infected pigs as well as field samples were compared by the ELISA and by an indirect hemagglutination assay (IHA). In experimental pigs, the earliest detectable antibody response was found to be almost identical for both assays, but for some of the pigs the time of detection was significantly earlier by blocking ELISA than by IHA. In naturally infected herds more samples were found to be positive by ELISA than by IHA. Furthermore, the results indicate that sera from naturally M. flocculare infected pigs may give rise to cross-reactions in the IHA. The blocking ELISA appears to be a valuable and reproducible tool in the surveillance and serodiagnosis of M. hyopneumoniae infections in pigs.

Animals↗

PubMed1991

Comparison of flow cytometry and virus isolation in cell culture for identification of cattle persistently infected with bovine viral diarrhea virus.

Detection of bovine viral diarrhea virus in 143 blood samples by virus isolation in cell culture and flow cytometry was performed. The material included 37 samples later shown to originate from persistently infected cattle. Thirty-three samples were positive by virus isolation, and all 37 samples were positive by the flow cytometric assay.

Animals↗

PubMed1990

Detection by enzyme-linked immunosorbent assay of Aujeszky's disease virus in tissues of infected pigs.

An enzyme-linked immunosorbent assay was developed for the detection of Aujeszky's disease virus antigen in tissue extracts and in nasal swabs. The enzyme-linked immunosorbent assay is based on two different monoclonal antibodies with specificity for the gII glycoprotein of Aujeszky's disease virus. Viral antigen was detected in 81 of 93 tissue extracts prepared from virus-infected organs. Fifteen outbreaks of Aujeszky's disease were analyzed in this study, and they were all identified by the gII antigen enzyme-linked immunosorbent assay.

Animals↗

PubMed1990

Flow cytometric detection of bovine viral diarrhea virus in peripheral blood leukocytes of persistently infected cattle.

Flow cytometry was investigated for detection of bovine viral diarrhea virus (BVDV) in peripheral blood mononuclear leukocytes of persistently infected cattle. The mononuclear leukocytes were purified by sedimentation in a gradient of Ficoll-Paque, fixed, permeabilized, and then labelled by indirect immunofluorescence using biotinylated immunoglobulins from a porcine antiserum to BVDV. Flow cytometric analysis of blood samples obtained from persistently infected cattle revealed virus in 3.0-21.0% (mean +/- SD, 11.2% +/- 6.4%) of the mononuclear leukocytes. Fluorescent cells were not observed in controls. Flow cytometric detection of BVDV in blood cells of persistently infected bovines is a rapid and objective technique which does not require cell culture facilities.

Animals↗

PubMed1989

[Thyrotoxicosis in patients hospitalized because for atrial fibrillation].

The thyroid parameters were investigated in 99 out of 167 patients with atrial fibrillation as the main diagnosis during a period of two years. Out of these, 22 had current or previous thyrotoxicosis. Sixteen patients with thyrotoxicosis out of 93 (17%) had raised thyroid parameters in connection with the present admission with atrial fibrillation. The mean age was 72 years. The indication for measurement of the thyroid parameters in the 16 patients with thyrotoxicosis and atrial fibrillation was the clinical suspicion of thyrotoxicosis in half of the patients while the remaining half had monosymptomatic atrial fibrillation. Thus, in eight out of 85 patients, the diagnosis of thyrotoxicosis was established solely by screening. Thyrotoxicosis should always be considered as a possible precipitating cause in patients with atrial fibrillation. On account of the frequency (15-20%) and the uncharacteristic symptoms, the thyroid parameters should always be examined routinely.

Adult↗

PubMedDate not supplied

Monoclonal blocking ELISA detecting serum antibodies to the glycoprotein gII of Aujeszky's disease virus.

A monoclonal blocking enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to Aujeszky's disease virus (ADV) in porcine serum was developed. This ELISA is based on the reaction between virus antigen immobilized in a microdilution plate and a monoclonal antibody (MAb) reactive with a highly stable epitope on a glycoprotein complex, gII, of ADV. The viral epitope was expressed by 18 European field, laboratory and vaccine strains of ADV. The MAb used in the test was selected among 15 MAbs all reactive with viral epitopes apparently recognized by the porcine immune system as well. Good agreement was found when serum samples from 375 pigs were tested in both a polyclonal and the monoclonal blocking ELISA.

Animals↗