Tumor cells, but not endothelial cells, mediate eradication of primary sarcomas by stereotactic body radiation therapy

Cancer clinics currently use high-dose stereotactic body radiation therapy as a curative treatment for several kinds of cancers. However, the contribution of vascular endothelial cells to tumor response to radiation remains controversial. Using dual recombinase technology, we generated primary sarcomas in mice with targeted genetic mutations specifically in tumor cells or endothelial cells. We selectively mutated the proapoptotic gene Bax or the DNA damage response gene Atm to genetically manipulate the radiosensitivity of endothelial cells in primary soft tissue sarcomas. Bax deletion from endothelial cells did not affect radiation-induced cell death in tumor endothelial cells or sarcoma response to radiation therapy. Although Atm deletion increased endothelial cell death after radiation therapy, deletion of Atm from endothelial cells failed to enhance sarcoma eradication. In contrast, deletion of Atm from tumor cells increased sarcoma eradication by radiation therapy. These results demonstrate that tumor cells, rather than endothelial cells, are critical targets that regulate sarcoma eradication by radiation therapy. Treatment with BEZ235, a small-molecule protein kinase inhibitor, radiosensitized primary sarcomas more than the heart. These results suggest that inhibiting ATM kinase during radiation therapy is a viable strategy for radiosensitization of some tumors.

The development of a population of 4D pediatric XCAT phantoms for imaging research and optimization

PURPOSE

We previously developed a set of highly detailed 4D reference pediatric extended cardiac-torso (XCAT) phantoms at ages of newborn, 1, 5, 10, and 15 yr with organ and tissue masses matched to ICRP Publication 89 values. In this work, we extended this reference set to a series of 64 pediatric phantoms of varying age and height and body mass percentiles representative of the public at large. The models will provide a library of pediatric phantoms for optimizing pediatric imaging protocols.

METHODS

High resolution positron emission tomography-computed tomography data obtained from the Duke University database were reviewed by a practicing experienced radiologist for anatomic regularity. The CT portion of the data was then segmented with manual and semiautomatic methods to form a target model defined using nonuniform rational B-spline surfaces. A multichannel large deformation diffeomorphic metric mapping algorithm was used to calculate the transform from the best age matching pediatric XCAT reference phantom to the patient target. The transform was used to complete the target, filling in the nonsegmented structures and defining models for the cardiac and respiratory motions. The complete phantoms, consisting of thousands of structures, were then manually inspected for anatomical accuracy. The mass for each major tissue was calculated and compared to linearly interpolated ICRP values for different ages.

RESULTS

Sixty four new pediatric phantoms were created in this manner. Each model contains the same level of detail as the original XCAT reference phantoms and also includes parameterized models for the cardiac and respiratory motions. For the phantoms that were 10 yr old and younger, we included both sets of reproductive organs. This gave them the capability to simulate both male and female anatomy. With this, the population can be expanded to 92. Wide anatomical variation was clearly seen amongst the phantom models, both in organ shape and size, even for models of the same age and sex. The phantoms can be combined with existing simulation packages to generate realistic pediatric imaging data from different modalities.

CONCLUSIONS

This work provides a large cohort of highly detailed pediatric phantoms with 4D capabilities of varying age, height, and body mass. The population of phantoms will provide a vital tool with which to optimize 3D and 4D pediatric imaging devices and techniques in terms of image quality and radiation-absorbed dose.

Organ localization: toward prospective patient-specific organ dosimetry in computed tomography

PURPOSE

With increased focus on radiation dose from medical imaging, prospective radiation dose estimates are becoming increasingly desired. Using available populations of adult and pediatric patient phantoms, radiation dose calculations can be catalogued and prospectively applied to individual patients that best match certain anatomical characteristics. In doing so, the knowledge of organ size and location is a required element. Here, the authors develop a predictive model of organ locations and volumes based on an analysis of adult and pediatric computed tomography (CT) data.

METHODS

Fifty eight adult and 69 pediatric CT datasets were segmented and utilized in the study. The maximum and minimum points of the organs were recorded with respect to the axial distance from the tip of the sacrum. The axial width, midpoint, and volume of each organ were calculated. Linear correlations between these three organ parameters and patient age, BMI, weight, and height were determined.

RESULTS

No statistically significant correlations were found in adult patients between the axial width, midpoint, and volume of the organs versus the patient age or BMI. Slight, positive linear trends were found for organ midpoint versus patient weight (max r(2) = 0.382, mean r(2) = 0.236). Similar trends were found for organ midpoint versus height (max r(2) = 0.439, mean r(2) = 0.200) and for organ volume versus height (max r(2) = 0.410, mean r(2) = 0.153). Gaussian fits performed on probability density functions of the adult organs resulted in r(2)-values ranging from 0.96 to 0.996. The pediatric patients showed much stronger correlations overall. Strong correlations were observed between organ axial midpoint versus age, height, and weight (max r(2) = 0.842, mean r(2) = 0.790; max r(2) = 0.949, mean r(2) = 0.894; and max r(2) = 0.870, mean r(2) = 0.847, respectively). Moderate linear correlations were also observed for organ axial width versus height (max r(2) = 0.772, mean r(2) = 0.562) and for organ volume versus height (max r(2) = 0.781, mean r(2) = 0.601).

CONCLUSIONS

Adult patients exhibited small variations in organ volume and location with respect to height and weight, but no meaningful correlation existed between these parameters and age or BMI. Once adulthood is reached, organ morphology and positioning seem to remain static. However, clear trends are evident between pediatric organ locations versus age, height, and weight. Such information can be incorporated into a matching methodology that may provide the highest probability of representing the anatomy of a patient undergoing a clinical exam to prospectively estimate the radiation dose.

A set of 4D pediatric XCAT reference phantoms for multimodality research

PURPOSE

The authors previously developed an adult population of 4D extended cardiac-torso (XCAT) phantoms for multimodality imaging research. In this work, the authors develop a reference set of 4D pediatric XCAT phantoms consisting of male and female anatomies at ages of newborn, 1, 5, 10, and 15 years. These models will serve as the foundation from which the authors will create a vast population of pediatric phantoms for optimizing pediatric CT imaging protocols.

METHODS

Each phantom was based on a unique set of CT data from a normal patient obtained from the Duke University database. The datasets were selected to best match the reference values for height and weight for the different ages and genders according to ICRP Publication 89. The major organs and structures were segmented from the CT data and used to create an initial pediatric model defined using nonuniform rational B-spline surfaces. The CT data covered the entire torso and part of the head. To complete the body, the authors manually added on the top of the head and the arms and legs using scaled versions of the XCAT adult models or additional models created from cadaver data. A multichannel large deformation diffeomorphic metric mapping algorithm was then used to calculate the transform from a template XCAT phantom (male or female 50th percentile adult) to the target pediatric model. The transform was applied to the template XCAT to fill in any unsegmented structures within the target phantom and to implement the 4D cardiac and respiratory models in the new anatomy. The masses of the organs in each phantom were matched to the reference values given in ICRP Publication 89. The new reference models were checked for anatomical accuracy via visual inspection.

RESULTS

The authors created a set of ten pediatric reference phantoms that have the same level of detail and functionality as the original XCAT phantom adults. Each consists of thousands of anatomical structures and includes parameterized models for the cardiac and respiratory motions. Based on patient data, the phantoms capture the anatomic variations of childhood, such as the development of bone in the skull, pelvis, and long bones, and the growth of the vertebrae and organs. The phantoms can be combined with existing simulation packages to generate realistic pediatric imaging data from different modalities.

CONCLUSIONS

The development of patient-derived pediatric computational phantoms is useful in providing variable anatomies for simulation. Future work will expand this ten-phantom base to a host of pediatric phantoms representative of the public at large. This can provide a means to evaluate and improve pediatric imaging devices and to optimize CT protocols in terms of image quality and radiation dose.

Chromosome translocations in couples with in-vitro fertilization implantation failure

Recurrent miscarriage is known to be associated with parental chromosomal abnormalities, particularly balanced reciprocal and Robertsonian translocations. The aim of this study was to test the hypothesis that couples with in-vitro fertilization (IVF) implantation failure, like those with recurrent miscarriage, have a higher than expected prevalence of translocations which may impact on pregnancy outcome. Patients who previously had at least 10 embryos transferred without achieving clinical pregnancy were evaluated for chromosome abnormalities as part of screening investigations for implantation failure. Recurrent miscarriage patients with a history of at least three consecutive first-trimester abortions were also tested. Results were compared to reports of infertility patients presenting for treatment and population neonatal screening programmes. Chromosomal abnormalities overall were detected in 13/514 individuals with implantation failure (2.5%), and 15/319 individuals with recurrent miscarriage (4. 7%). Translocations (reciprocal and Robertsonian) were found in 7/514 individuals (1.4%) and 7/219 couples (3.2%) with implantation failure (P < 0.0005 compared with infertile controls and P < 0.0001 compared with screened neonates). Translocations were found in 13/319 individuals (4.1%) and 12/130 couples (9.2%) with recurrent miscarriage. Balanced parental translocations may be implicated in the pathogenesis of IVF-implantation failure. Genetic evaluation should be considered as part of the investigation of these patients.

Comparison of a 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-t etrazolium hydroxide (XTT) colorimetric method with the standardized National Committee for Clinical Laboratory Standards method of testing clinical yeast isolates for susceptibility to antifungal agents

MICs for clinical Candida and Cryptococcus isolates were determined by a method incorporating the colorimetric indicator 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl] -2H-tetrazolium hydroxide (XTT), and the results were compared with MICs obtained by the National Committee for Clinical Laboratory Standards approved standard method (M27-A). One hundred percent of all isolates demonstrated agreement within 2 dilutions between the MICs of amphotericin B, fluconazole, itraconazole, ketoconazole, and flucytosine obtained by the two methods. These data suggest that an XTT-based method could provide a useful means for the determination of antifungal susceptibility of yeasts.

Drug calculation competencies of graduate nurses

This study describes the analysis of the mathematical ability of 220 registered nurses (RNs) from six Victorian universities who applied for a graduate year program at St Vincent's Hospital, Melbourne. Each applicant completed a drug calculation competency test (DCCT) which required them to calculate 11 drug dosages commonly performed by RNs in clinical practice. The results revealed that 58 percent (n = 127) of the 220 applicants were not able to accurately calculate all 11 drug dosages. The results also demonstrated significant differences between applicants from respective universities. The findings suggest that there are fundamental problems with the mathematical competencies of this group of newly graduated nurses. The results may also support the assertion that the educational preparation of these nurses at the undergraduate level could be enhanced in some universities and does not appear to adequately prepare nurses to perform basic drug calculations which are frequently required in the acute setting.

Effect of castration on metalloprotease activities in the lateral, dorsal, and anterior lobes of the rat prostate

Several proteolytic enzymes are involved in mediating the regression of the prostate gland following castration. A previous study showed that plasminogen activator activities are elevated only in the ventral lobe by castration in the rat. Since matrix metalloproteases represent a different class of protease that degrade extracellular matrix, this study examined their activities in the lateral, dorsal, and anterior lobes of the rat in response to androgen deprivation. The results indicate that, in contrast to plasminogen activators, metalloprotease activities are increased in the lateral, dorsal, and anterior lobes following orchiectomy. This suggests that differences in regulation of certain proteases by androgens may occur in individual prostatic lobes.

Onset, natural history and outcome in idiopathic adult motor neuron disease

Cases of adult-onset idiopathic motor neuron disease (MND) identified from January 1970 through December 1986 were studied in a defined area of California. The patients were followed prospectively throughout the illness in 99% of cases. Among 708 cases aged 25-74 years at onset, the most common type (86%) was typical, sporadic amyotrophic lateral sclerosis (SporALS). The risk of bulbar onset and shorter survival times increased with age in both men and women. About 4%, mainly younger men, experienced unusually long courses with milder paralysis, but could not be identified early in the illness. They probably represent one extreme of the ALS spectrum rather than a distinct subtype. Familial ALS (FamALS) was diagnosed in 7%. It developed earlier in life but ran a slightly longer course, which suggests a different disease process. Overall there was a statistically significant predominance of males, especially in 17 cases (2%) of progressive muscular atrophy (PMA). There were 26 cases (4%) classified as primary lateral sclerosis (PLS). Progressive bulbar palsy was not found; that diagnosis usually denotes merely the bulbar onset of ALS.

Spinal fluid cells and protein in amyotrophic lateral sclerosis

The cerebrospinal fluid total protein in 385 cases of sporadic amyotrophic lateral sclerosis showed no relationship to survival, but it was related to survival time in 34 cases of familial amyotrophic lateral sclerosis. Infrequent and mild pleocytosis, and oligoclonal bands seemed to have no clinical significance in well established cases of amyotrophic lateral sclerosis.

Gelatinolytic and caseinolytic proteinase activities in human prostatic secretions

Seminal fluid contains a number of proteinase activities, many of which are secreted by the prostate gland. Our objective was to determine proteinase activities in human prostatic secretions which can degrade gelatin and/or casein. Prostatic secretions were collected by prostate massage from men with benign prostatic hyperplasia prior to surgery to relieve obstruction. Significant proteinase activities towards gelatin of about 81, 86, 94, 111, 115 and 163 Kd as well as less active forms of 23, 36, 38, 132, 137, and 148 Kd were detected using protein substrate-polyacrylamide gel zymography. In addition, Ca2+ stimulated activities of approximately 64, 66, 71 and 76 Kd; however, EDTA and EGTA inhibited all activities but the 23, 36 and 38 Kd forms (these were inhibited by benzamidine and epsilon-amino caproic acid). This suggests that the gelatinolytic activities of 64 Kd and greater were metalloproteinases and those of 23, 36, and 38 Kd were serine proteinases. Significant caseinolytic activities of 22, 25, 35, 37, 57, 90, 96, 102 and 116 Kd were found as well as several less active forms and a 12 Kd activity stimulated by Ca2+. Caseinolytic activities of 12, 14, 16, 96, 102, 116, and 126 Kd were inhibited by EDTA and EGTA indicating they are metalloproteinases. The 35, 37, 57 and 58 Kd caseinolytic activities were inhibited by benzamidine, and the 57 and 58 Kd forms by epsilon-aminocaproic acid suggesting they were serine proteinases. There was considerable variability among individuals in the molecular forms of proteinase activity expressed as well as the level of their activity. A significant decrease in the frequency of expression of the 132 Kd gelatinolytic activity was found in secretions from men with atypia or adenocarcinoma, as compared with men with benign prostatic hyperplasia alone. Our results show that human prostatic secretion contains a variety of proteinase activities. The expression of the 132 Kd gelatinolytic activity could prove useful in further evaluation of neoplastic prostatic disease.

Multidimensional Health Locus of Control: a new perspective on the psychopathology of anxiety and depression?

The primary purpose of the study was to assess the validity of the reported relationship between an ‘externalised’ locus of control and the psychopathology of anxiety and depression. 36 clinical out-patients primarily presenting as anxious, depressed or both and 46 normal controls were tested on the Multidimensional Health Locus of Control together with self-rating scales of anxiety and depression. With regard to the clinical group in particular, the hypothesised relationships between the ‘Chance’ and ‘Powerful Others’ dimensions of locus of control and the psychopathology of depression and anxiety did not emerge. In contrast, although the normal group showed no correlation of locus of control scores with depression, a positive and significant correlation was displayed with anxiety as measured by Spielberger's State-Trait Anxiety Inventory. Implications for current theoretical formulations for psychopathology, scale specificity, and the need to delineate client populations carefully were discussed.

Optical effects of gas flow through an optical train: an experimental determination

High power laser optical systems often require gas flow in the optical train to control effects such as thermal blooming. The gas flow is itself a source of optical degradation for the laser beam. An experimental investigation has been performed for a scale simulation of a typical optical train. Optical effects of the type of gas used and the method of flow injection have been ascertained. It was determined that substantial optical degradation can be caused by the flow, and a number of qualitatively desirable flow implementations, which produced little degradation, were identified.

The obsessive compulsive syndrome as a neurotic device for the reduction of self-uncertainty

In 1957, Lewis, writing about obsessional neurotic illness, stated: ‘There has been no marked increase in our state of knowledge of it in recent years, and indeed much of what can be found on the subject in current textbooks had already been fully stated and closely discussed in the first two decades of this century ….’ A recurrent theme in the literature is the supposed relationship between obsessional neurotic illness and ‘obsessional’ character traits. The psychoanalytic view that there is a strong association between obsessional symptoms and the ‘anal’ character traits was disputed by Lewis (1935). He found little evidence to support the existence of a well-marked constellation of character traits, or of a relationship between ‘obsessional’ traits and obsessional neurotic illness. Sandler and Hazari (1960) gave supportive evidence for the psychoanalytic view, but Reed (1970) doubted whether their conclusions were justified by the findings. Makhlouf-Norris (1968) summarized the literature in fourteen points, two of which are outlined below.