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J Lehtovirta

Publications and source records attributed to J Lehtovirta.

6 recordsLinked to original sources
PubMed2001

General practitioners' willingness to request plain lumbar spine radiographic examinations.

OBJECTIVES: To examine general practitioners' attitudes to plain lumbar spine radiographic examinations. DESIGN: A postal questionnaire consisting of questions on background data and doctors' opinions about plain lumbar spine radiographic examinations, as well as eight vignettes (imaginary patient cases) presenting indications for lumbar radiography, and five vignettes focusing on the doctors' willingness to request lumbar radiography on the basis of patients' age and duration of symptoms. The data were analysed according to the doctor's age, sex, workplace and the medical school of graduation. SETTING: Finland. SUBJECTS: Six hundred and fifteen randomly selected physicians working in primary health care (64% of original target group). RESULTS: The vignettes revealed that the use of plain lumbar radiographic examination varied between 26 and 88%. Patient's age and radiation protection were the most prominent factors influencing doctors' decisions to request lumbar radiographies. Only slight differences were observed between the attitudes of male and female doctors, as well as between young and older doctors. Doctors' willingness to request lumbar radiographies increased with the patient's age in most vignettes. The duration of patients' symptoms had a dramatic effect on the doctor's decision: in all vignettes, doctors were more likely to request lumbar radiography when patient's symptoms had exceeded 4 weeks. CONCLUSIONS: General practitioners commonly use plain lumbar spine radiographic examinations, despite its limited value in the diagnosis of low back pain. Further consensus and medical education is needed to clarify the indications for plain lumbar radiographic examination.

Adult↗
PubMed1996

Evaluation of a rapid strip test for insulin-like growth factor binding protein-1 in the diagnosis of ruptured fetal membranes.

We evaluated the clinical usefulness of a new bedside test (PROM TEST) for insulin-like growth factor binding protein-1 (IGFBP-1) in the detection of ruptured fetal membranes (ROM). Cervicovaginal secretion was sampled between 15 and 37 weeks of gestation from asymptomatic women with apparently intact membranes and from women with clinically confirmed ROM, as well as from symptomatic women with suspected ROM based on history. IGFBP-1 in samples was detected with a dipstick based on immunochromatography. The test result was positive in 100% of cases with unequivocal ROM and in 5.3% of cases with apparently intact membranes. Furthermore, the PROM TEST was positive in 64 of 181 patients evaluated for suspected ROM based on history, but in whom the diagnosis could not be clinically confirmed at the initial evaluation. Fifty of the 64 women (78.1%) were delivered prematurely (< 37 weeks). Five of the 117 PROM-negative patients had elective cesarean section for reasons unrelated to ROM before 37 weeks and 10 of the remaining 112 patients (8.9%) had preterm delivery. Women with equivocal ROM and a positive test result had a 6.9-fold increased relative risk (95% confidence interval 4.2-11.4) of preterm delivery compared with women who had a negative result at the time of evaluation. Multiple logistic regression including PROM TEST result, contractions, vaginal bleeding and cervical changes indicated that a positive PROM TEST result was an independent predictor of preterm delivery (P = 0.0001). In summary, a positive PROM TEST result identifies ROM with high sensitivity and a negative result effectively excludes those with intact membranes. In patients with suspected but clinically unconfirmed ROM, the positive test result is associated with increased risk of preterm delivery, suggesting that microruptures of fetal membranes can also be detected by the PROM TEST.

Adult↗
PubMed1994

Type IV collagenases in human amniotic fluids and amnion epithelial cells.

Gelatin zymograms revealed in human second trimester amniotic fluids a constant M(r) 66,000 proteolytically active polypeptide that in immunoblotting was recognized by antiserum against the human fibroblast gelatinase/type IV collagenase. Isolated cultured human amnion epithelial cells produced the M(r) 66,000 proteinase and frequently a M(r) 92,000 one. The production of the former was enhanced by transforming growth factor-beta and that of the latter by tetradecanoyl phorbol acetate. Immunoprecipitation experiments indicated that the M(r) 66,000 amnion epithelial cell proteinase was identical with that found in the amniotic fluids and that the M(r) 92,000 one corresponded to the human macrophage/granulocyte gelatinase/type IV collagenase. Approximate quantifications of the M(r) 66,000 proteinase in amniotic fluids and sera from same individuals were assessed by comparison of dilution series of the samples and standard enzyme preparations in zymography. These measurements indicated that the amount of the proteinase in the amniotic fluids was about 5-10 micrograms/ml representing 0.1-0.2% of total proteins. In sera the corresponding figures were 30-40 micrograms/ml and 0.03-0.06%, respectively. Thus the relative concentration of the M(r) 66,000 proteinase in amniotic fluids was approx. 3-4-fold that in sera, suggesting local production of the protein. The proteinase may be produced by amnion epithelial cells that under so far unknown physiologic stimulus also may start secreting the M(r) 92,000 enzyme.

Amnion↗
PubMedDate not supplied

Image processing in digital chest radiography: effect on diagnostic efficacy.

The usefulness of digital image processing of chest radiographs was evaluated in a clinical study. In 54 patients, chest radiographs in the posteroanterior projection were obtained by both 14 inch digital image intensifier equipment and the conventional screen-film technique. The digital radiographs (512 x 512 image format) viewed on a 625 line monitor were processed in three different ways: (1) standard display; (2) digital edge enhancement for the standard display; and (3) inverse intensity display. The radiographs were interpreted independently by three radiologists. The diagnoses were confirmed by CT, follow-up radiographs and clinical records. Chest abnormalities of the films analyzed included 21 primary lung tumors, 44 pulmonary nodules, 16 cases with mediastinal disease and 17 cases with pneumonia/atelectasis. Interstitial lung disease, pleural plaques, and pulmonary emphysema were found in 30, 18 and 19 cases, respectively. The sensitivity of conventional radiography when averaged overall findings was better than that of the digital techniques (P less than 0.001). The differences in diagnostic accuracy measured by sensitivity and specificity between the three digital display modes were small. Standard image display showed better sensitivity for pulmonary nodules (0.74 vs 0.66; P less than 0.05) but poorer specificity for pulmonary emphysema (0.85 vs. 0.93; P less than 0.05) compared with inverse intensity display. We conclude that when using 512 x 512 image format, the routine use of digital edge enhancement and tone reversal at digital chest radiographs is not warranted.

Adolescent↗