Polymorphisms of the GSTM1 and GSTT1 genes in patients with allergic diseases in the Czech population

BACKGROUND: Allergic diseases belong to the most common chronic disorders affecting mankind and their prevalence in population is increasing. Several studies have indicated that oxidative stress impairs pulmonary function and makes existing asthma worse. Members of the glutathione-S-transferase (GST) superfamily of genes are important in protection of cells from reactive oxygen species. AIMS OF THE STUDY: Relationships among allergic diseases including asthma and variations in the GST mu (GSTM1) and GST theta (GSTT1) genes were investigated in 1,006 Caucasian subjects. METHODS: The multiplex polymerase chain reaction protocol was used for simultaneous amplification of both genes for molecular analysis. Genotype frequencies among patients and controls were assessed and the associations of the genotypes with intermediary phenotypes of allergy were statistically determined. RESULTS: The frequencies of GST null genotypes did not differ significantly between patients with allergic diseases (or asthma alone) and healthy controls. However, when compared with patients homozygous or heterozygous for GSTM1 functional allele, asthmatics carrying both GSTM1 null alleles displayed significantly worse lung function, assessed by forced expiratory volume in 1 s/forced vital capacity (FEV(1)/FVC) ratio (Tiffenau index), (P < 0.01). CONCLUSIONS: Genetic polymorphisms of the GSTM1 and GSTT1 genes, both individually and in combination, were not associated with the development of allergic diseases including asthma in the Czech population, the GSTM1 gene variability, however, may influence lung functions in our asthmatics.     

高三尖杉酯碱酰胺的结构测定

三尖杉树皮粗提取物中的一个新生物碱—高三尖杉酯碱酰胺(homoharringtonamide)的结构,经质谱—质谱分析,初步建议为16。类似的酰胺类生物碱,例如三尖杉碱酰胺(cephalotaxamide,6)、11-羟基三尖杉碱酰胺(11-hydroxycephalotaxamide,9)、三尖杉酯碱酰胺(harfingtonamide,14)或异三尖杉酯碱酰胺(isoharringtonamide,15)也可能存在,后三者(9,14,15)尚未见报道。     

Blood loss and replacement in total hip arthroplasty: a multicenter study. The Preoperative Autologous Blood Donation Study Group

To determine blood loss, the number of transfusions, and the hemoglobin levels achieved in patients via transfusion in the course of total hip arthroplasty, 324 patient records from 1987 through 1989 were reviewed at three university and three community hospitals. Calculated blood loss was 3.2 +/- 1.3 units in primary procedures and 4.0 +/- 2.1 units in revision procedures (mean +/- SD). Of 777 red cell units transfused, 455 (59%) were autologous units. Transfused patients received 2.0 +/- 1.8 units for primary procedures and 2.9 +/- 2.3 units for revision procedures (mean +/- SD). The maximum number of units given to 95 percent of the transfused patients was 4 for primary procedures and 6 for revision procedures. The mean postoperative hemoglobin level after all transfusions was 103 to 110 g per L, regardless of patient age group of physical status, autologous donor status, or hospital. No difference in length of hospital stay was observed for patients less than 65 years old with hemoglobin concentrations of 80 to 139 g per L at discharge.     

Serum profiles of insulin-like growth factors and their binding proteins in adults with growth hormone receptor deficiency treated with insulin like growth factor I

Six adult patients with growth hormone receptor deficiency (GHRD) (2 men, 4 women) with an identical defect in the growth hormone receptor (GHR) gene, were treated with recombinant human insulin-like growth factor I (IGF-I), 40 μgikg S.C. twice daily, for 7 days. Serum concentrations of IGF peptide and IGF binding protein-3 (IGFBP-3) were measured by specific radioimmunoassays; serum IGFBPs were also measured by Western ligand blotting. The size distribution of both IGF-I and IGF-II was measured in serum following size-exclusion fast-performance liquid chromatography. IGF-I treatment resulted in a normalization of serum IGF-I levels on days 1–7 of treatment and a decrease in serum IGF-II levels. The fall in IGF-II levels and the simultaneous rise in IGF-I levels, however, resulted in an unchanged total serum IGF level. The low IGFBP-3 values did not significantly change during treatment, whereas there was a slight increase in IGFBP-2 levels. Preliminary analysis of size-fractionated sera suggested an increase in IGF-I levels in the 40 and 150 kDa regions at the expense of IGF-II levels. The results suggest that despite the failure of IGF-I treatment to increase IGFBPs significantly, serum IGFBP concentrations were sufficient to maintain normal levels of IGF-I. 0 Laron syndrome, growth hormone receptor deficiency, insulin-like growth factors, insulin-like growth factor binding protein     

Quality assurance of dynamic parameters in volumetric modulated arc therapy

Objectives

The purpose of this study was to demonstrate quality assurance checks for accuracy of gantry speed and position, dose rate and multileaf collimator (MLC) speed and position for a volumetric modulated arc treatment (VMAT) modality (Synergy® S; Elekta, Stockholm, Sweden), and to check that all the necessary variables and parameters were synchronous.

Methods

Three tests (for gantry position–dose delivery synchronisation, gantry speed–dose delivery synchronisation and MLC leaf speed and positions) were performed.

Results

The average error in gantry position was 0.5° and the average difference was 3 MU for a linear and a parabolic relationship between gantry position and delivered dose. In the third part of this test (sawtooth variation), the maximum difference was 9.3 MU, with a gantry position difference of 1.2°. In the sweeping field method test, a linear relationship was observed between recorded doses and distance from the central axis, as expected. In the open field method, errors were encountered at the beginning and at the end of the delivery arc, termed the “beginning” and “end” errors. For MLC position verification, the maximum error was −2.46 mm and the mean error was 0.0153 ±0.4668 mm, and 3.4% of leaves analysed showed errors of >±1 mm.

Conclusion

This experiment demonstrates that the variables and parameters of the Synergy® S are synchronous and that the system is suitable for delivering VMAT using a dynamic MLC.The concept of volumetric modulated arc therapy (VMAT) has been described in many studies [1-5]. VMAT is a system for intensity-modulated radiotherapy treatment (IMRT) delivery that achieves high dose conformity by optimising the dose rate, gantry speed and leaf positions of the dynamic multileaf collimator (MLC) [6]. One study [5] demonstrated quality assurance (QA) checks using dynamic MLC controller log files (Dynalog) for VMAT systems such as RapidArc® (Varian Medical Systems Inc., Palo Alto, CA). It is assumed that the actual delivery process is truly represented in the log files [6]. The major disadvantage of this method is that Dynalog files need to be validated against an independent system. The electronic portal imaging device (EPID) is a dependable system when corrections are made for systematic tilts and shifts [7,8] and when image sagging due to gantry angle [9] has been taken into account. A significant number of researchers have investigated MLC QA by film or EPID [7-13] to measure the accuracy of the MLC controller independently and ensure that the MLC edge positions agree with the radiation field edges to within 0.3 mm [14]. EPID measurements are highly reproducible, with a standard deviation of <0.1 mm for individual leaf/collimator positions and <0.05 mm for a 10×10 cm² field [7]. Few studies [15-17] have demonstrated commissioning, QA and patient-specific QA for VMAT using both the RapidArc and the Synergy® S (Elekta, Stockholm, Sweden) systems. The purpose of this study was to demonstrate QA checks for accuracy of gantry speed and position, dose rate, MLC leaf speed and MLC position, and to ensure that all the necessary variables and parameters were synchronous. These simple tests were designed to fulfil the requirements and limits recommended by the American Association of Physicists in Medicine (AAPM) for the clinical implementation of IMRT [18] and a recent recommendation by AAPM task group 142 (TG-142) [19] for the QA of medical accelerators.     

Mid-trimester loss--appraisal of a screening protocol

The main causes for mid-trimester loss are known. There is likely to be overlap with those of first trimester loss, but the proportions may be different. We wished to perform an aetiological survey in a large population of patients with a history of recurrent miscarriage, for possible explanations for their second trimester miscarriages. Database analysis of 636 patients attending a UK University Teaching Hospital dedicated miscarriage clinic between 1991 and 1996 revealed a 25% prevalence (n = 158) for second trimester miscarriage. Results from an investigative screening protocol were positive in 50% of cases: 33% (n = 52) tested positive for antiphospholipid syndrome (APS); 8% (n = 13) fulfilled strict criteria for cervical incompetence; there was a 4% prevalence of uterine anomaly; 3% for infection (n = 5) and 2% of patients (n = 3) proved to be hypothyroid. Importantly, dual pathology was found in 5% of patients with a history of second trimester miscarriage. As idiopathic mid-trimester loss is a diagnosis by exclusion, a high index of suspicion is required, as are modern diagnostic techniques.      

Breast MR imaging with loop-gap resonators

Breast images obtained at 1.5 T using a loop-gap resonator pair as both the excitation and detection device are presented. The efficiency of this approach is high, as judged by the low level of radio frequency (RF) power required to obtain a 90 degree pulse and the uniformity of the RF field within the resonator pair. A modification of the pair geometry provides for reasonable observation of the tissues through the chest wall and laterally to the axillae.     

Polymorphisms of glutathione S-transferase M1, T1 and P1 in patients with reflux esophagitis and Barrett’s esophagus

Reflux esophagitis (RE) and Barrett’s esophagus (BE) belong to the most common esophageal complications of gastroesophageal reflux disease. Glutathione S-transferase (GST) enzymes play an important role in cellular protection against oxidative stress and toxic foreign chemicals. Therefore, we investigated the hypothesis that polymorphisms in genes for these detoxifying enzymes could influence susceptibility to RE and BE. GSTM1, GSTT1 and GSTP1 loci were analyzed by PCR-based methods in 64 patients with RE (and an additional group of 22 subjects with BE as the fourth grade of esophagitis) and 173 unrelated controls. There were no significant differences in the distributions of GSTM1 and GSTT1 genotypes between the controls and patients with RE or BE. Similarly, frequencies of GSTP1 alleles were non-significantly different between the control and RE groups. However, GSTP1 B allele carriers were more frequent among the patients with BE compared to those in the reflux esophagitis group (P = 0.04, OR = 2.10, 95% CI 0.99–4.44) and most significantly when compared to the controls (P = 0.0067, P _corr < 0.05, OR = 2.56, 95%CI 1.30–5.05). Although the GSTM1 and GSTT1 genes did not show any relationship with reflux disease, the GSTP1 gene might be one of the risk factors associated with susceptibility to RE, especially to BE.