An improved formula for determination of the activity via the sum-peak method.

The sum-peak method principally enables determination of the absolute activity of gamma cascade emitting sources based only on the use of spectral data, without knowledge of the detector efficiencies. However, to achieve better accuracy of the activity results, corrections due to pile-up, accidental coincidences, electronic noise and angular correlations must be introduced into the proposed method. Such corrections usually require the collection of a few gamma spectra and additional extrapolations, thereby further complicating the experimental procedures. In this paper, it is shown that by using pile-up peaks for corrections of accidental coincidences, Monte Carlo techniques for angular correlation, and LLD corrections, the source activity can be measured with accuracy and reproducibility below 1% using only one gamma spectrum, without any additional extrapolations.

Granulation effects on the radon emanation rate.

The radon emanation and the granulation effect on the emanation rate of several building materials (ceramic plates, sand, red brick and siporex brick) with different (226)Ra concentrations were investigated. A ball mill was used to achieve different granulations of the materials. The particle size distributions were determined by a particle size analyser (Mastersizer 2000). The increase in the (222)Rn concentration inside a closed chamber (volume ≈5.4 × 10(-3) m(3)) due to emanation from each material with different granulations was measured by an alpha spectrometer (RAD7). Thus, time-dependent curves for radon concentrations were obtained. The highest radon emanation coefficient (27 %) was obtained for the siporex sample with the smallest grain size (0.34 µm). For the ceramic pads, the granulation effect was negligible and the emanation coefficient was very low (∼0.4 %). The strongest influence of granulation on the radon emanation rate was found for the siporex brick sample.

Solution equilibria between ethylenediamine-N,N'-di-3-propionate and some transition metal(II) ions.

Solution equilibria between the ligand ethylenediamine-N,N'-di-3-propionate (eddp(2-)) and copper(II), nickel(II) or cobalt(II) ions were studied by glass electrode pH-metric and spectrophotometric measurements in 0.1 M NaCl ionic medium at 298.0+/-0.2 K. In the concentration limits 1.0

Metanephric adenoma: histology, immunophenotype, cytogenetics, ultrastructure.

Metanephric adenoma is a rare renal neoplasm that is histologically and clinically unique. We found this neoplasm in a 54-year-old woman. This large, well-circumscribed, solid, tan tumor showed histologic similarity to developing metanephric tubular epithelium. It is composed of uniformly small epithelial cells forming tubules. Immunohistochemical evaluation showed that the tumor cells express proximal tubule marker URO-2 and wt1 gene protein product, commonly expressed in Wilms' tumors. Ultrastructurally, the epithelial cells were characterized by the presence of cilia on the luminal side and were resting on an abundant basement membrane. Cytogenetic analysis showed normal female karyotype. The unique features of metanephric adenoma should be clinically and pathologically recognized because of its invariably benign course.

Defining the proper attribution of responsibility for quality of care.

The term "medical care" is frequently used when either "health care" or "patient care" would be more accurate. This inaccurate use of terminology not only fosters the impression that physicians have sole responsibility for the entire health care system, but also hinders efforts to place properly the actual responsibility for the quality of care. This article proposes three precise definitions, based on the unique features that distinguish health care, patient care, and medical care, which emphasize the characteristics of each domain. Proper use of these definitions can prevent the confusion of one area of care with another, and should ultimately result in the quality of each area becoming better defined, and thereby better controlled.

[Prenatal diagnosis using chorionic biopsy in the 1st trimester of pregnancy]. / Antenatalna dijagnostika horionom biopsijom u I trimestru trudnoce.

One hundred-sixteen pregnant women were subjected to chorionic villi sampling at the gestational age of 8-11 weeks. In 12 cases, the transabdominal approach was used, and in the rest of the cases, a flexible catheter was placed transcervically. The most frequent indication was the age of the pregnant women (over 35). Chorionic villi sampling was successfully performed in 97.5% of cases. Fetal loss amounted to 1.9%.

[Obstetrical approach in prenatal diagnosis in the first and second trimester of pregnancy]. / Akuserski postupci antenatalne dijagnostike u prvom i drugom trimestru trudnoce.

From 712 women-patients in Genetic Consultation Department 284 of them were submitted to antenatal diagnostics. The most common indications were old age of pregnant women or a malformed child in the previous pregnancies or in the family. Horion biopsy was done in 118 patients and amniocentesis was performed in the I and II trimester of pregnancy in 188 of them. The fetal loss according to the weeks of pregnancy in the groups, where was done the antenatal diagnostic treatment was not significantly different from horion biopsy was 1.9% and the success of cultivating of horion tissue was 98%. The findings of chromosome analysis were confirmed in all cases.

Organizational control of hospital infrastructure determines the quality of care.

Hospital personnel and their performance underlie all hospital facilities and patient services (the hospital infrastructure). Hence, quality patient care is not exclusively in the domain of the medical staff and must be regarded as a comprehensive responsibility of the hospital. Hospitals must establish behavioral quality systems and teach employees not only how to do their job well to meet technical quality standards, but also how to fulfill patient expectations. Critical and life threatening problems are thereon prevented or minimized, and protection of physicians and hospitals from litigation improves as a result. Governing boards must provide a role model and demand excellence of everyone, in order to improve the performance of the hospital infrastructure.

The hospital infrastructure: the key to quality patient care.

The quality of patient care depends on the strength of a hospital's infrastructure. In this article, the author discusses ways to strengthen the hospital infrastructure and thereby improve the hospital environment and the quality of hospital services.

A simple technique for obtaining high quality chromosome preparations from chorionic villus samples using FdU synchronization.

A fluorordeoxyuridine (FdU) synchronization technique was applied to 30 chorionic villus samples (CVS) from patients undergoing first trimester fetal diagnosis. The villi were incubated for 15 h in the presence of FdU. The block in DNA synthesis was subsequently released using thymidine and after an additional 5 h of incubation the mitotic cells were arrested in metaphases using a high concentration of colcemid. This method results in improved morphology of the chromosomes and a high mitotic index. A diagnostic chromosome analysis could be obtained in each clinical case using at least 15 well-spread metaphases. G-banded karyotypes were prepared of four metaphases in each case. The diagnostic procedure was completed within 48 h from the time of CVS. Use of this technique significantly improves the success rate of 'direct' chromosome analyses from CVS in a busy cytogenetic laboratory.