Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Error Sources”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 973 records · Page 54Linked to original sources
PubMed1981

[Tocolysis in imminent premature delivery: limits of indication--assessment of success--sources of error (author's transl)].

303 imminent premature deliveries were treated from 1977 to 1978 with hexoprenaline (Gynipral) on an inpatient basis. Indication for tocolysis was obtained according to the tocolysis index (Baumgarten). Cases with an index of three and more were evaluated only. This criterion enabled accurate separation between prophylactic and therapeutic tocolysis. By means of postpartal determination of the age of gestation via the Dubowitz score, the period of gestation was controlled which had been determined at the beginning of the tocolysis. This made it possible to detect erroneous indication due to false estimation of the gestation period. Tocolysis success was assessed according to two different aspects. Pharmacodynamic success was assumed if 15 or more points were attained according to the Weidinger success score. This occurred in 56,5% of all treated patients. Clinical success, defined by delivery of a child which did not die perinatally nor suffered from the respiratory distress syndrome, was seen in 90.7% of all treated patients.

Adult↗
PubMed1981

Comparison of derived and actual transferrin: a potential source of error in clinical nutritional assessment.

A prospective study was undertaken to evaluate the utility of calculating transferrin from total iron-binding capacity in the nutritional assessment of burned patients. Regression analysis was used to compare total iron-binding capacity with radial immunodiffusion transferrin determinations. The method used for calculating transferrin (0.8 TIBC - 43) is a frequently published conversion formula for deriving transferrin. One hundred twenty-five data sets were obtained from 45 burned patients. Values for derived transferrin ranged from 39 to 235 mg/dl, averaging 121 mg/dl. Actual transferrin averaged 162 mg/dl, ranging from 41 to 320 mg/dl. Forty-eight actual serum transferrin samples were normal (greater than 172 mg/dl) whereas only 17 derived transferrin values were normal. While there is a correlation between total iron-binding capacity and serum transferrin (r = 0.85), to calculate transferrin according to the formula above would have resulted in significant error in the clinical assessment of the patients' nutritional status (p less than 0.001). From our studies, the formula for conversion of total iron-binding capacity to transferrin was found to be (0.68 TIBC + 21). These results suggest that the development of a universal conversion factor is not feasible. Modification of the formula may be necessary at each institution for clinically useful evaluations of serum transferrins are to be derived from iron-binding capacity for use in nutritional assessment.

Adolescent↗
PubMed1981

[The anatomical basis and sources of error of selective and supraselective gastric vagotomies (author's transl)].

An anatomical study, based essentially upon 38 dissections of formol-preserved specimens, was used to identify the different characteristics of the vagus nerve which might have an influence on different vagotomy techniques. The arrangement of the different vagal structures (principal and accessory) at the oesophageal orifice is described in full. The most criminal branches are pointed out with particular emphasis. Distribution branches unknown or poorly known up to the present have been demonstrated. The principal nerves of the lesser curvature and their endings are reviewed in the context of supraselective vagotomy. The discussion emphasis the most important anatomical details relevant to the achievement of adequate supraselective vagotomy.

Adult↗
PubMed1980

Nonspecific binding as a source of error in thyrotropin radioimmunoassay with polyethylene glycol as separating agent.

We investigated the effects of nonspecific binding on thyrotropin values obtained by radioimmunoassay in which polyethylene glycol is used as precipitant. Differences in nonspecific binding among individual samples were significant (F-test, p less than 0.001, range 5.5 to 14.1%). Non-specific binding and total serum protein were directly correlated (r = 0.472, n = 59; p less than 0.001). Nonspecific binding increased with increasing concentrations of globulins but showed no relation to albumin concentration. If globulin concentration was less than 15 g/L, precipitation of the antigen--antibody complex by polyethylene glycol was incomplete. The mean value for thyrotropin in sera from 67 healthy subjects was 2.7 (SD 0.3) milli-international units per liter (milli-int. unit/L) without individual serum nonspecific binding correction, significantly (p less than 0.005) higher than that with nonspecific binding correction (1.6, SD 0.1, milli-int. unit/L). Evidently, inter-sample variations in nonspecific binding may cause significant errors under these conditions, which can be minimized by taking into account the individual nonspecific binding of each serum sample.

Evaluation Studies as Topic↗
PubMed1980

Dilution as a source of error: implications for preparation and calibration of laboratory standards and for quality control of radioimmunoassays.

Although dilution of materials is generally accepted to involve some error, workers often assume that this error may be discounted. However, comparing solutions of two identical materials diluted in the same way shows that dilution errors can cause a considerable departure from the expected identity. I describe this effect and its dependence on the errors at various stages of the dilution process.

Quality Control↗