Distribution of hemoglobin phenotypes in four different districts of Porto Velho, Rondônia, Brazil.

Hemoglobin profile studies have been carried out in four samples from different districts of Porto Velho (Rondônia State) in the western Amazonian region of Brazil: Candelária, Bate Estaca, Hemeron (at the State Blood Bank), and São Carlos. Samples from 337 unrelated individuals were collected during medical and paramedical team visits by professionals from the Instituto de Pesquisa em Patologia Tropical and the Centro de Pesquisa em Patologias Tropicais (both research institutes in tropical diseases). The aim of this study is to assess the frequency of alleles in the hemoglobin system, mainly alleles HB*A, *S, and *E. The overall phenotype frequencies were HB A,S = 0.025, HB A,E = 0.006, and HB A,A = 0.969. Samples from the blood bank subjects and samples from the homogeneous areas of São Carlos and Candelária plus Bate Estaca have a chi-square of heterogeneity of 6.383 (p = 0.041) and 8.406 (p = 0.015), respectively. The allele frequencies (HB*A = 0.984, HB*S = 0.012, and HB*E = 0.003) do not significantly differ from frequencies found in other Brazilian regions.

Comparison of quantitative cytomegalovirus (CMV) PCR in plasma and CMV antigenemia assay: clinical utility of the prototype AMPLICOR CMV MONITOR test in transplant recipients.

The correlation between the prototype AMPLICOR CMV MONITOR test (Roche Molecular Systems), a quantitative PCR assay, and the cytomegalovirus (CMV) pp65 antigenemia assay was evaluated in transplant recipients. Sequential blood specimens were collected on 29 patients (491 specimens), the leukocyte fraction was tested by CMV antigenemia, and quantitative PCR was performed on plasma specimens. None of the 15 patients (242 specimens) who were antigenemia negative were positive for CMV DNA by PCR, and none of these patients developed active CMV disease. There were 14 antigenemia-positive patients, 8 of whom developed active CMV disease. In all patients, there was a good association between the antigenemia and PCR assays. Ganciclovir-resistant virus was isolated from three patients with active CMV disease. These three patients had persistently elevated levels of antigenemia and CMV DNA by PCR when resistance to ganciclovir developed. This standardized, quantitative CMV PCR assay on plasma has clinical utility for the diagnosis of active disease and in monitoring the response to antiviral therapy in transplant recipients.

Effect of bedside shielding on air-kerma rates around gynecologic intracavitary brachytherapy patients containing 226Ra or 137Cs.

An anthropomorphic phantom was implanted with 226Ra or 137Cs gynecologic intracavitary brachytherapy sources. Air-kerma rate measurements were taken at 10-cm increments along a horizontal plane from the side of the bed at 50 cm, 87 cm, and 136 cm heights above the floor. Five portable lead shields were placed at the head, at the foot and along one side of the bed and readings were taken again at the corresponding heights above, below and behind the shields. The readings were normalized to 100-mg Ra equivalence, and air-kerma rate curves were drawn allowing for the comparison of 226Ra and 137Cs with and without lead shields. The data demonstrated that the air-kerma rates for 137Cs were reduced more than those for 226Ra with the use of the portable lead shields. There was four times the transmission with 226Ra than with 137Cs. The optimal placement was with the lateral bedside shields proximal to the head and foot closest to the bed, with the middle shield overlapping in back. The shields at the head and foot should extend out and overlap the bedside shields. The level of the sources should be positioned near the bottom of the shields. This information will provide the medical health physicist with an estimate of air-kerma rates for both 226Ra and 137Cs with and without shielding for evaluating personnel exposures as well as the effectiveness of current shielding in relation to radiation protection requirements in adjacent rooms or hallways.

Effects of asymmetric photopeak windows on flood field uniformity and spatial resolution of scintillation cameras.

Pulse height analyzer windows that are set on the high side of the photopeak are known to improve spatial resolution and contrast when used for scintillation camera imaging. Asymmetric windows can be used with some scintillation cameras that have energy correction circuitry. In this study the improvement in spatial resolution and loss of field uniformity for 99mTc, 201Tl, and 131I were measured as a function of window asymmetry (up to 30%, defined relative to the loss of counts as compared to a symmetric window under intrinsic conditions). Flood field uniformity was inversely related to the degree of window asymmetry. With 10 cm of scatter the 99mTc integral uniformity deteriorated from 7.9% with a symmetric window to 11.5% for a 30% asymmetric window. The corresponding values for 201Tl were 9.9 and 10.9%. Even without additional scatter, the values for 131I were 23.0 and 26.5%. Spatial resolution, as measured by the full width at half maximum in 10 cm of scatter improved by only 5% for 99mTc and 7% for 201Tl. However, the full width at tenth maximum increased by as much as 20% for 99mTc and 201Tl. A large percentage of this improvement was attained with small degrees of asymmetry. This study demonstrates that 10% or less asymmetry can provide most of the benefit in spatial resolution and contrast that is to be gained without significant losses in field uniformity and count rate.

Improved emergency room medication distribution.

A system developed to improve drug distributions, safety and control in the emergency room of a 400-bed hospital is described. The system centers around the use of a special cabinet containing medication bins which store selected and limited quantities of medications packaged in single-unit containers. A dditionally, intravenous solutions, irrigating solutions, eye tray medications, medications for cardiopulmonary resuscitation and refrigated drugs are kept in areas of ready access. Punched cards containing information on the drug are stored with the medication and are used for billing and reordering purposes. A 24-hour supply of medications that may be dispensed after the pharmacy closes are packaged in prelabeled, zipper-locked plastic bags. The system results in improved safety as well as long-term cost savings.