Dose rate constants for 125I, 103Pd, 192Ir and 169Yb brachytherapy sources: an EGS4 Monte Carlo study

An exhaustive revision of dosimetry data for 192Ir, 125I, 103Pd and 169Yb brachytherapy sources has been performed by means of the EGS4 simulation system. The DLC-136/PHOTX cross section library, water molecular form factors, bound Compton scattering and Doppler broadening of the Compton-scattered photon energy were considered in the calculations. The absorbed dose rate per unit contained activity in a medium at 1 cm in water and air-kerma strength per unit contained activity for each seed model were calculated, allowing the dose rate constant (DRC) A to be estimated. The influence of the calibration procedure on source strength for low-energy brachytherapy seeds is discussed. Conversion factors for 125I and 103Pd seeds to obtain the dose rate in liquid water from the dose rate measured in a solid water phantom with a detector calibrated for dose to water were calculated. A theoretical estimate of the DRC for a 103Pd model 200 seed equal to 0.669 +/- 0.002 cGy h(-1) U(-1) is obtained. Comparison of obtained DRCs with measured and calculated published results shows agreement within 1.5% for 192Ir, 169Yb and 125I sources.     

The psychosocial impact of caregiving on young people who have a parent with an illness or disability: Comparisons between young caregivers and noncaregivers.

Objective: To investigate the psychosocial impact of young caregiving by empirically validating prominent qualitative themes. This was achieved through developing an inventory called the Young Caregiver of Parents Inventory (YCOPI) designed to assess these themes and by comparing young caregivers and noncaregivers. Method: Two hundred forty-five participants between 10 and 25 years completed questionnaires: 100 young caregivers and 145 noncaregivers. In addition to the YCOPI, the following variables were measured: demographics, caregiving context, social support, appraisal, coping strategies, and adjustment (health, life satisfaction, distress, positive affect). Results: Eight reliable factors emerged from the YCOPI that described the diverse impacts of caregiving and reflected the key themes reported in prior research. The factors were related to most caregiving context variables and theoretically relevant stress and coping variables. Compared with noncaregivers, young caregivers reported higher levels of young caregiving impact, less reliance on problem-solving coping, and higher somatization and lower life satisfaction. Conclusions: Findings delineate key impacts of young caregiving and highlight the importance of ensuring that measures used in research on young caregivers are sensitive to issues pertinent to this population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Composite materials with an intermetallic matrix based on nickel and titanium monoaluminides hardened by oxide particles or fibers

Hardening phase/intermetallic matrix pairs are chosen for composite materials (CMs) intended for long-term high-temperature operation. These materials must have high and stable mechanical properties during a long time at high temperatures and loads. The compatibility of the physicochemical and mechanical properties of CM components is estimated to choose hardening phase/intermetallic matrix pairs in which the matrix is represented by an alloy based on NiAl or TiAl monoaluminide and the hardening phase is a refractory thermodynamically stable oxide of a Group III transition metal M ₂O₃. The following two schemes are used to perform hardening of a CM with a matrix consisting of a TiAl or NiAl alloy by the most thermodynamically stable interstitial phases, i.e., refractory oxides, at temperatures higher than the operating temperature (T _op) of the IMM. The first scheme consists in creating Al₂O₃/TiAl CMs hardened by continuous single-crystal sapphire fibers using the impregnation of a bundle of single-crystal fibers with a matrix melt followed by directional solidification. The TiAl-based matrix in these CMs serves as a binder connecting oxide phase fibers and preventing them from fracture due to high adhesion forces between oxide fibers and the matrix and a high fiber/matrix interface strength. In the second scheme, Y₂O₃/NiAl CMs are produced by powder metallurgy methods, which include severe deformation by extrusion accompanied by the formation of deformation texture and subsequent recrystallization annealing. In these CMs, disperse refractory oxide particles stabilize grain boundaries in a recrystallized matrix material and lead to the formation of directional structures with coarse elongated grains and a low fraction of transverse boundaries. Al₂O₃/TiAl CMs containing 20–25 vol % hardening single-crystal sapphire Al₂O₃ fibers can operate at temperatures of 1000–1050°C (∼0.7T _m of matrix), which is 250–300°C higher than the maximum values of T _op of a TiAl-based matrix and 400-450°C higher than the maximum values of T _op of a Ti-based matrix. An Y₂O₃/NiAl composite with a directionally recrystallized structure of a NiAl-based matrix hardened by 2.5 vol % Y{ia2}O₃ particles can be recommended for operation at temperatures of 1400–1500°C ((0.8–0.9)T _m of matrix), which are higher by 100–400°C than not only T _op but also T _m of Ni superalloys.     

GBR with an e-PTFE membrane associated with DFDBA: histologic and histochemical analysis in a human implant retrieved after 4 years of loading

As a result of a fracture to the cemented post and core, a pure titanium implant was extracted from a 54-year-old patient after 4 years of clinical loading. At implantation, the implant was positioned into an extraction socket and the defect was treated with an e-PTFE membrane associated with a DFDBA graft. At retrieval the implant underwent histologic and histochemical examination to assess the characteristics of the regenerated bone after 4 years of prosthetic loading. The implant showed an angular bony defect at the smooth collar, but the bone-implant direct contact rate seemed to be elevated in the remaining implant surface. Normal transmitted and polarized light examinations demonstrated that most of the DFDBA particles were resorbed and substituted by vital newly formed bone. The regenerated bone appeared compact with secondary osteons and large haversian canals; however, some partially mineralized remnants residuated in the spaces, between the osteons. Within the limits of this study, the authors concluded that DFDBA can be substituted by the host bone, but the rate of substitution is very slow and not complete after 4 years. From a clinical point of view, however, the load-bearing capacity of the bone regenerated with the membrane technique associated with DFDBA appeared to be similar to that of normal bone.     

The impact of an information pack on patients with stroke and their carers: a randomized controlled trial

OBJECTIVES: To assess the impact of information packs on patients with stroke and their carers, and to pilot some of the methodology for a trial of a Family Support Organiser (FSO). SUBJECTS: Seventy-one patients admitted to Oxford hospitals with acute stroke during February-July 1995, and 49 informal carers of these patients. DESIGN: Randomized controlled trial. Intervention group received an Information pack containing various Stroke Association publications one month after their stroke, or at discharge from hospital, whichever was sooner. Control group received nothing. Follow-up was by interview at the place of residence of the patients six months after their stroke. MEASURES: Outcome measures assessed knowledge about stroke; satisfaction with information received; patient behaviour in terms of access to community services and benefits; and health status and quality of life. RESULTS: Patients and carers in the intervention group tended to know more about stroke, but these differences were not significant once adjusted for age. Patients in the intervention group (but not carers) tended to be more satisfied with the information that they had received, but the differences were not significant. There were no differences with regard to any aspects of quality of life in patients in the intervention group, though carers in the intervention group were found to have significantly better mental health (p = 0.04). CONCLUSIONS: While the study was too small to generate firm conclusions, information leaflets may lead to improved knowledge about stroke several months after they have been distributed. This finding is worth following up with larger studies. The stroke knowledge questionnaire that was piloted in this trial seems to be able to detect differences between groups.     

Phototoxicity associated with diclofenac: a photophysical, photochemical, and photobiological study on the drug and its photoproducts

Diclofenac (1) is a photosensitizing nonsteroidal antiinflammatory drug. Its photodecomposition gives rise to chlorocarbazole 2a. This product undergoes photodehalogenation to 3a in a subsequent step. When the photobiological activities of 1, 2a, and 3a are compared by means of the photohemolysis test, it is clearly observed that chlorocarbazole 2a causes cell lysis with a markedly higher efficiency than the parent drug or the secondary photoproduct 3a. Laser flash photolysis studies suggest that photodehalogenation of 2a occurs from its excited triplet state via quenching by ground-state 2a and formation of an excimer. As a consequence, an aryl radical plus an N-centered carbazolyl radical are formed. These radical intermediates appear to be responsible for the observed photobiological effects of diclofenac, via hydrogen abstraction from the target biomolecules, which initiates a type-I photodynamic effect. The efficient peroxidation of model lipids, such as linoleic acid, photosensitized by 2a are in favor of this proposal. Thus, the photosensitizing properties of diclofenac appear to be associated with the photochemical and photobiological activity of its major photoproduct.     

Heat-induced membrane damage combined with adriamycin on prostate carcinoma PC-3 cells: correlation of cytotoxicity, permeability and P-glycoprotein or metallothionein expression

Sodium thiopental, as other amphiphilic molecules, interacts with the membrane by inserting into the lipid bilayer and causing alterations of the membrane properties such as curvature and hypotonic lysis resistance. But can it modify the mechanical properties of the membrane? In the present work it was observed that sodium thiopental affected the membrane rheological properties by improving erythrocyte deformability; this effect resulted from a reduction of both the elastic modulus and surface viscosity. In erythrocytes devoid of sialic acid after treatment with neuraminidase, sodium thiopental membrane concentration was significantly higher than in normal cells, suggesting that drug access to the lipid bilayer be facilitated by the absence of the steric and electrostatic barrier of the glycocalyx negative charges. From a rheological point of view, desialated and normal cells showed the same response to the anesthetic as regards elastic modulus but in opposite direction if surface viscosity was considered. This finding supports the hypothesis that sodium thiopental molecules enter the bilayer of desialated cells in a higher proportion, as compared to the normal erythrocyte, promoting a disorganization that results in a greater inner friction. The changes in the rheological parameters, triggered by sodium thiopental, could be attributed to the bilayer contribution to the membrane mechanical properties, either directly or through interaction between the bilayer and the cytoskeleton.     

Genetic and environmental influences on the continuous scales of the Myers-Briggs Type Indicator: an analysis based on twins reared apart

The effects of 1/1000 field recommended concentration of the organophosphorus compounds; edifenphos and glyphosate on the immune response and protein contents were investigated after different time intervals. The cell mediated immune response assessed by proliferative response of splenocytes to mitogens; phytohemagglutinin (PHA) and concanavalin A (Con A) for T cell and lipopolysaccharide (LPS) for B cell decreased significantly in tems of the level of stimulation index in the treated fish and reached maximal depression after 4 weeks. Humoral immunity assessed as splenic antibody plaque forming cells (PFC) measured after 5 days in vitro immunization to sheep erythrocytes (SRBC's) were suppressed in a concentration dependent pattern by the two compounds. The estimated ED50 for the PFC/10(6) cells of edifenphos and glyphosate were 1.48 x 10(-2) uM and 1.65 x 10(-2) uM respectively. The data also showed that serum antibody titres in the treated fish were decreased in a time dependent manner. The total protein content of serum treated with the two pesticides was decreased after different time periods compared with control. The blood serum of treated and untreated Tilapia nilotica were analyzed electrophoretically for protein components and the percentage of proteins in each fraction was determined.     

Trends and patterns of mortality associated with birth defects and genetic diseases in the United States, 1979-1992: an analysis of multiple-cause mortality data

Contemporary information on the trends and patterns of mortality associated with birth defects and genetic diseases is lacking in the United States. To study these trends and patterns, we used the Multiple-Cause Mortality Files of the National Center for Health Statistics. From 1979 through 1992, 320,208 deaths in the United States were associated with birth defects and genetic diseases. The age-adjusted mortality rates for people with birth defects declined from about 8.2/100,000 in 1979 to about 6.7/100,000 in 1992, and the mortality rates for people with genetic diseases increased from 2.2/100,000 in 1979 to 2.5/100,000 in 1992. The mortality rate was higher among men than among women and higher among blacks than among whites or other races for both birth defect- and genetic disease-associated deaths. The rate among infants with birth defects was more than 25 times higher than that among other age groups. About half of the children whose deaths were associated with birth defects had cardiovascular system defects, 15% had central nervous system defects, and 12% had chromosomal defects. For deaths associated with genetic diseases, hereditary neurologic or storage disorders were the most common genetic diseases (38%), followed by metabolic disorders (21%), sickle cell and thalassemia (12%). The decline in the rate of mortality from birth defects in the United States probably reflects improvements in medical and surgical care and other factors. Most of the mortality associated with birth defects remains in the pediatric age group (less than 15 years old). The upward trend we detected for the deaths with genetic diseases was most likely related to improved recognition and reporting of some genetic diseases rather than to the increased prevalence.     

The lifestyle assessment questionnaire: an instrument to measure the impact of disability on the lives of children with cerebral palsy and their families

Suitable measures of health and morbidity are less readily available for children than they are for adults. We present a measure, which is used to describe the impact of impairment and disability on the lives of children with cerebral palsy and their families. The development of this measure involved data collected from 691 children with cerebral palsy contained within the North-East England Cerebral Palsy Register and born between 1960 and 1985. Uniquely, multidimensional scaling techniques were used to derive dimensions analogous with those described in the International Classification of Impairments, Disabilities, and Handicaps. We present the analyses undertaken to test the properties of the tool, which show that it is a reliable and valid measure of the disadvantages experienced by children with cerebral palsy.     

Microfabricated device coupled with an electrospray ionization quadrupole time-of-flight mass spectrometer: protein identifications based on enhanced-resolution mass spectrometry and tandem mass spectrometry data

We describe the coupling of a microfabricated fluidic device to an electrospray ionization (ESI) quadrupole time-of-flight mass spectrometer (QqTOFMS) for the identification of protein samples. The microfabricated devices consisted of three reservoirs connected via channels to a main capillary, which in turn was linked via a microspray interface to the QqTOFMS. Here we present preliminary results obtained using this system. Standardized solutions of myoglobin tryptic digest were analyzed indicating a limit of detection at the low to sub fmol/microL. The combination of the microfabricated device for rapid sample delivery and the rapid acquisition capability, enhanced resolution and mass accuracy of the QqTOF offers unique possibilities for the rapid identification of proteins by database searching. This platform can generate MS data suitable for protein database searching by the peptide-mass fingerprinting approach and MS/MS data suitable for protein database searching. Here the results of the two database-searching approaches are compared and the possibilities of combining the two approaches for rapid identification of protein are discussed. Also, we present a comparison of the results obtained using the three-position microfabricated device coupled to the ESI-QqTOFMS and to an ESI-ion trap MS. Finally the combination of C-terminal 18O labeling of peptides and the microfabricated system for automated combined peptide-mass fingerprinting and sequence-tag database searching is discussed.     

Cytopathology of retrograde renal pelvis brush specimens: an analysis of 40 cases with emphasis on collecting duct carcinoma and low-intermediate grade transitional cell carcinoma

We report our experience with 40 retrograde renal brush samples of pelvic-calyceal lesions with confirmatory tissue studies. On-site cytopathologic evaluation was performed in 38 of these specimens. The final histologic diagnoses included 24 cases of transitional cell carcinoma (TCC), 17 of which were low-intermediate grade tumors. All 24 cases were diagnosed cytologically as TCC (22), or as suspicious for TCC (2). Three cases classified as collecting duct carcinomas were resected; the cytologic specimens in 2 of these cases were interpreted as TCC, and one as reactive change. There were three renal cell carcinomas (RCC); cytologically, one was considered a papillary neoplasm, one suspicious for malignancy, and one as reactive. Two cases of atypical renal cysts were reported as suspicious for malignancy in both cytologic and histologic material. There was one case of metastatic colon carcinoma identified in the brush specimen. Finally, tissue studies in the remaining 7 cases showed reactive/inflammatory changes; however, four of the corresponding pelvic brush specimens were considered abnormal. A review of the above cases is reported with the objective of presenting the cytologic features seen in collecting duct carcinoma, low-intermediate grade TCC, and diagnostically difficult cases with cyto/histomorphologic discrepancies. The contribution of on-site assessment to diagnostic accuracy is also discussed.     

Treatment with calcium antagonists does not increase the risk of fatal or non-fatal cancer in an elderly mid-European population: results from STEPHY II. Starnberg Study on Epidemiology of Parkinsonism and Hypertension in the Elderly

OBJECTIVE: To assess the relationship between use of calcium antagonists and incidence of fatal or non-fatal cancer over 3 years in the Starnberg Study on Epidemiology of Parkinsonism and Hypertension in the Elderly (STEPHY) population. DESIGN: A prospective cohort study with follow-up analysis after 3 years. PATIENTS AND METHODS: In 1992 STEPHY workers investigated the total population aged > 65 years (n = 1190) of two villages in Bavaria, Germany. With 982 participants (response rate 83%) the prevalence of 'actual' hypertension (blood pressure > or = 160/95 mmHg or treatment) was 53%. Of all hypertensives (n = 491), 54% were being treated, 28% (n = 137) with calcium antagonists. Participants with a history of cancer or manifest cancer were excluded from further analysis. In 1995 in STEPHY II, the 3-year follow-up, we assessed total mortality (including cases of fatal cancer), cardiovascular events and cases of non-fatal cancer between 1992 and 1995. The evaluation included a second interview, use of case records of general practitioners and hospitals and analysis of the official death certificates. The total incidence of fatal and non-fatal cancer (a combined end point) was calculated for participants treated with calcium antagonists and those not taking calcium antagonists. RESULTS: Total mortality over 3 years was 12.1 % (n = 119). There were 22 deaths due to cancer and 75 cases of newly diagnosed non-fatal cancer. The combined incidence of fatal and non-fatal cancer (primary end point) was 10.9% (n = 15) for participants treated with calcium antagonists and 9.7% (n = 82) for those not taking calcium antagonists (odds ratio 1.12, 95% confidence interval 0.7-1.8). There was also no significant difference between the incidences of fatal cancer (2.2% in both groups), non-fatal cancer (12.5% for participants treated with calcium antagonists and 10.8% for those not taking calcium antagonists) and total mortality (14.6% for participants taking calcium antagonists and 11.7% for those not treated with calcium antagonists). CONCLUSION: Use of calcium antagonists does not increase the risk of fatal or non-fatal cancer over 3 years in an elderly mid-European population.     

The influence of HLA-matched sibling donor availability on treatment outcome for patients with AML: an analysis of the AML 8A study of the EORTC Leukaemia Cooperative Group and GIMEMA. European Organization for Research and Treatment of Cancer. Gruppo Italiano Malattie Ematologiche Maligne dell'Adulto

To determine whether patients with a HLA-identical sibling donor have a better outcome than patients without a donor, an analysis on the basis of intention-to-treat principles was performed within the framework of the EORTC-GIMEMA randomized phase III AML 8A trial. Patients in complete remission (CR) received one intensive consolidation course. Patients with a histocompatible sibling donor were then allocated allogeneic bone marrow transplantation (alloBMT), the patients without a donor were randomized between autologous BMT (ABMT) and a second intensive consolidation (IC2). 831 patients <46 years old and alive >8 weeks from diagnosis were included. HLA typing was performed in 672 patients. AlloBMT was performed during CR1 in 180 (61%) out of 295 patients with a donor. Another 38 patients were allografted: five in resistant disease, 14 during relapse and 19 in CR2. ABMT was performed in 130 (34%) out of 377 patients without a donor in CR1, in six (2%) patients during relapse and in 38 (10%) patients during CR2. The disease-free survival (DFS) from CR for patients with a donor was significantly longer than for patients without a donor (46% v 33% at 6 years; P=0.01, RR 0.78, 95% confidence interval 0.63-0.96). The overall survival from diagnosis for patients with a donor was longer, but not statistically significant, than for patients without a donor (48% v 40% at 6 years; logrank P=0.24). When patients were stratified according to prognostic risk groups, the same trend in favour of patients with a donor was seen for survival duration and the DFS remained significantly longer for this group of patients.