Impact of knee support and shape of tabletop on rectum and prostate position

PURPOSE: To evaluate the impact of different tabletops with or without a knee support on the position of the rectum, prostate, and bulb of the penis; and to evaluate the effect of these patient-positioning devices on treatment planning. METHODS AND MATERIALS: For 10 male volunteers, five MRI scans were made in four different positions: on a flat tabletop with knee support, on a flat tabletop without knee support, on a rounded tabletop with knee support, and on a rounded tabletop without knee support. The fifth scan was in the same position as the first. With image registration, the position differences of the rectum, prostate, and bulb of the penis were measured at several points in a sagittal plane through the central axis of the prostate. A planning target volume was generated from the delineated prostates with a margin of 10 mm in three dimensions. A three-field treatment plan with a prescribed dose of 78 Gy to the International Commission on Radiation Units and Measurements point was automatically generated from each planning target volume. Dose-volume histograms were calculated for all rectal walls. RESULTS: The shape of the tabletop did not affect the rectum and prostate position. Addition of a knee support shifted the anterior and posterior rectal walls dorsally. For the anterior rectal wall, the maximum dorsal shift was 9.9 mm (standard error of the mean [SEM] 1.7 mm) at the top of the prostate. For the posterior rectal wall, the maximum dorsal shift was 10.2 mm (SEM 1.5 mm) at the middle of the prostate. Therefore, the rectal filling was pushed caudally when a knee support was added. The knee support caused a rotation of the prostate around the left-right axis at the apex (i.e., a dorsal rotation) by 5.6 degrees (SEM 0.8 degrees ) and shifts in the caudal and dorsal directions of 2.6 mm (SEM 0.4 cm) and 1.4 mm (SEM 0.6 mm), respectively. The position of the bulb of the penis was not influenced by the use of a knee support or rounded tabletop. The volume of the rectal wall receiving the same dose range (e.g., 40-75 Gy) was reduced by 3.5% (SEM 0.9%) when a knee support was added. No significant differences were observed between the first and fifth scan (flat tabletop with knee support) for all measured points, thereby excluding time trends. CONCLUSIONS: The rectum and prostate were significantly shifted dorsally by the use of a knee support. The rectum shifted more than the prostate, resulting in a dose benefit compared with irradiation without knee support. The shape of the tabletop did not influence the rectum or prostate position.     

Oral risperidone plus oral lorazepam versus standard care with intramuscular conventional neuroleptics in the initial phase of treating individuals with acute psychosis

Although atypical antipsychotics are now considered first line treatments for schizophrenia, intramuscular (i.m.) conventional neuroleptics are often still considered necessary in emergency treatment of acute psychoses. This European, multicentre, open-label, active-controlled trial compared oral risperidone plus oral lorazepam to standard care with i.m. conventional neuroleptics with or without lorazepam in the emergency treatment of acutely psychotic patients. Patients were allowed to choose either oral risperidone (a single dose of 2 mg and 2.0-2.5 mg lorazepam; 121 patients) or standard i.m. treatment (conventional neuroleptic with or without lorazepam; 105 patients). No additional treatment was allowed for 2 h. Primary outcome was the percentage of patients with treatment success (asleep or at least much improved on Clinical Global Impression-global improvement scale) 2 h after treatment initiation. Baseline characteristics were similar in both treatment groups. Oral risperidone plus oral lorazepam was more successful at 2 h (66.9%) and significantly non-inferior compared to standard i.m. care (54.3%; P=0.0003), and the incidence of extrapyramidal symptoms (EPS) was lower (1.7%) compared to standard i.m. care (9.5%). In acutely psychotic patients requiring emergency treatment, oral risperidone/oral lorazepam was at least as effective as i.m. conventional neuroleptic treatment with or without lorazepam. Oral risperidone plus lorazepam rapidly reduces symptoms, including aggression, and causes fewer EPS.     

Group work in a Dutch home care organization: does it improve the quality of working life?

Home care in The Netherlands is facing a trend towards increasing workloads, giving it the image of an unattractive sector to work in. To deal with increasing workloads and their effects, many solutions have been developed, including the concept of team or group work. This paper will address the possibilities, conditions and effects involved in the implementation of group work in home care as a means of improving the quality of working life (QWL) in this sector. To this end I have studied QWL in three jobs in two organizations for home care, one of which implemented group work. This comparison concludes that jobs in the team-based organization are more complete and challenging, bringing more job decision latitude, but also higher work pressure.     

1H-NMR spectroscopy of cerebrospinal fluid of fetal sheep during hypoxia-induced acidemia and recovery

The purpose of the study was to investigate the sequence of processes occurring during and after hypoxia-induced acidemia. We used proton nuclear magnetic resonance spectroscopy, which provides an overview of metabolites in cerebrospinal fluid (CSF), reflecting neuronal metabolism and damage. The pathophysiological condition of acute fetal asphyxia was mimicked by reducing maternal uterine blood flow in 14 unanesthetized pregnant ewes. CSF metabolites were measured during hypoxia-induced acidemia, and during the following recovery period, including the periods at 24 and 48 h after the hypoxic insult. Maximum values of the following CSF metabolites were reached during severe hypoxia (pH 相似文献   

Maturity of the adrenal cortex in very preterm infants is related to gestational age

To study the maturity of the adrenal cortex in preterms born before 33 wk of gestation, basal levels of cortisol and cortisone and the cortisol and 17-hydroxyprogesterone (17-OHP) response to 1 microg/kg adrenocorticotropic hormone stimulation were measured in 24 appropriate-for-gestational age preterm infants (26-33 wk; 690-1985 g). Gestational age influenced the response of cortisol, 17-OHP, and the ratio between cortisol/17-OHP in the studied infants. In preterms born <30 wk of gestation, levels of cortisol, and the ratio between cortisol/17-OHP were lower compared with preterms born between 30 and 33 wk. Levels of cortisone were higher in preterms born <30 wk, suggesting a lower activity of 11 beta-hydroxysteroid dehydrogenase that may be related to maturity as well. These findings indicate that the adrenal cortex function in preterm infants is closely related to the duration of gestation and may be important in neonatal morbidity.     

Contralateral inhibition in a release from forward masking

The current study investigated contralateral inhibition involved in a release from forward masking. The masker and probe were 1-kHz pure tones shaped by a 20-Hz modulation. Durations of the masker and probe were 500 ms and 50 ms (single cycle) respectively. A 10-ms delay between the masker and probe was added to rule out any confusion. A contralateral component (cue), with various spectral and temporal properties, could be added during the masker. The first experiment showed that masking release occurred more often or increased with an increasing number of spectral cue components. The second experiment showed that increasing cue duration, leaving the cue and masker offsets synchronous, increased detection thresholds. In the third experiment the temporal position of a short cue relative to the masker was varied. The lowest thresholds were obtained for 0- and 150-ms delays between the cue and masker offsets. Despite large individual differences, the obtained release from forward masking provided support for a contralateral inhibition process. Contralateral inhibition seemed to be dependent on the number of spectral cue components and on the delay between the cue onset and the masker offset.     

Three-dimensional display modes for CT colonography: conventional 3D virtual colonoscopy versus unfolded cube projection

The authors compared a conventional two-directional three-dimensional (3D) display for computed tomography (CT) colonography with an alternative method they developed on the basis of time efficiency and surface visibility. With the conventional technique, 3D ante- and retrograde cine loops were obtained (hereafter, conventional 3D). With the alternative method, six projections were obtained at 90 degrees viewing angles (unfolded cube display). Mean evaluation time per patient with the conventional 3D display was significantly longer than that with the unfolded cube display. With the conventional 3D method, 93.8% of the colon surface came into view; with the unfolded cube method, 99.5% of the colon surface came into view. Sensitivity and specificity were not significantly different between the two methods. Agreements between observers were kappa = 0.605 for conventional 3D display and kappa = 0.692 for unfolded cube display. Consequently, the latter method enhances the 3D endoluminal display with improved time efficiency and higher surface visibility.     

Inactivation of deoxycytidine kinase and overexpression of P-glycoprotein in AraC and daunorubicin double resistant leukemic cell lines

AraC resistance in vitro is explained by inactivation of dCK, while resistance to DNR is described by overexpression of multidrug efflux pumps like Pgp or MRP. Thus far, no correlation between resistance mechanisms in vitro and in patients with AML has been documented. We generated AraC and DNR double resistant cell lines to investigate resistance mechanisms of both agents. In these cell lines involvement of dCK was extensively investigated and Pgp expression and activity was determined. Our data implicate that similar resistance mechanisms like inactivation of dCK coincided by alternatively spliced dCK forms and overexpression of Pgp are induced in single-as well as in double resistant leukemic cell lines.     

Free and total 2,5-hexanedione in biological monitoring of workers exposed to n-hexane in the shoe industry

OBJECTIVES: To analyse the role of total 2,5-hexanedione (2,5-HD) compared with free 2,5-HD as a biological indicator of exposure to n-hexane at work. METHODS: One-hundred and thirty two workers in contact with this solvent during their occupation in the shoe industry in the province of Alicante (Spain) were studied. Environmental and biological tests were carried out analysing variations of the concentration of the metabolite in urine corresponding to different working conditions. Environmental exposure was evaluated in each work place using active personal monitors and measured by gas chromatography (GC). Dichloromethane extracts of the urine samples collected at the end of the working shifts were analysed, before (determining free 2,5-HD, the toxic metabolite) and after acid hydrolysis (pH 0.1) (yielding the total 2,5-HD) and also by GC. The concentration of conjugated metabolite 4,5-dihydroxy-2-hexanone was calculated from the difference between total and free 2,5-HD. RESULTS: Free 2,5-HD represented an average of 14.2% of the total 2,5-HD determined in urine, and this percentage increased significantly (P<0.01) with higher environmental levels of acetone. Other factors, such as absorption through the skin (depending on the use of gloves) and the day on which samples were taken also significantly affected the relation between the two indicators and their respective relationships with environmental concentrations of n-hexane. CONCLUSION: Although analyses of the relationship between the levels of atmospheric n-hexane and those of metabolites in urine show a greater correlation for total 2,5-HD than for free 2,5-HD, our results suggest that free 2,5-HD could be a better indicator in evaluating risk of exposure to n-hexane, since the concentration is directly related to the neurotoxic effect.     

Very low levels of the glucocorticoid receptor beta isoform in the human hippocampus as shown by Taqman RT-PCR and immunocytochemistry

The hippocampus is an important target for glucocorticoid hormones. Glucocorticoid receptor (GR) mediated feedback in this area is important for control of behavioural adaptation. An alternative splice variant, the GRbeta (GRbeta) isoform, does not bind ligand and has been proposed to inhibit classic GRalpha-mediated transactivation of target genes. Hence, an increased ratio of GRbeta to GRalpha may induce relative corticosteroid-resistance, as e.g. presumed to occur in major depression. To investigate whether GRbeta is involved in the human hippocampus, we studied GRalpha and GRbeta expression levels in postmortem hippocampal tissue of control subjects by quantitative PCR (Taqman RT-PCR) and immunocytochemistry. Taqman RT-PCR demonstrated a very low relative abundance of GRbeta in the human hippocampus (GRalpha:GRbeta ratio approximately 14,500:1). Immunohistochemical analysis confirmed the occurrence of isolated profiles indeed displaying nuclear staining in the main hippocampal subregions. Subsequent double immunofluorescent analysis revealed that >98% of these GRbeta positive cells were double positive for leucocyte common antigen, that identifies exclusively blood-derived cells of haematopoietic origin, including microglia. We conclude that GRbeta is present in very low amounts in the control human hippocampus, and that of these low numbers of cells, notably, almost all are derived from blood which is inevitably present in postmortem tissue. A functionally relevant role for the GRbeta in control of the human hippocampus is therefore not very likely. Whether this is altered in disease conditions awaits further research.