drp, A novel cell density regulated protein

Growing cells are continuously processing signals of all varieties and responding to these signals by changes in cellular gene expression. One signal that cells in close proximity relay to each other is cell-cell contact. Non-transformed cells respond to cell-cell contact by arrest of growth and entry into G$\sb0,$ a process known as contact inhibition. Transformed cells do not respond to contact inhibition and continue to grow to high cell density, forming foci when in cell culture and tumors in the living organism. The events surrounding the generation, transduction, and response to cellular contact are poorly understood. In the present study, a novel gene product, drp, is shown to be expressed at high levels in cultured cells at high cell density. This density regulated protein, drp, has an apparent molecular weight of 70 kDa. Northern analysis shows drp to be highly expressed in cardiac and skeletal muscle and least abundant in lung and kidney tissues. By homology to two independently derived sequence tagged sites (STSs) used in the human genome project, drp or a closely related sequence maps to human chromosome 12. Density-dependent increases in drp expression have been demonstrated in six different cell lines including NIH 3T3, Hela and a human teratocarcinoma cell line, PA-1. Cells exhibit increased drp expression both when they are plated at increasing concentrations per unit area, or plated at low density and allowed to grow naturally to higher cell density. Cells at high density can exhibit several phenotypes including growth arrest, accumulation of soluble factors in the media, and increased numbers of cell contacts. Growth arrest by serum starvation or TGF-$\beta$ treatment fails to produce an increase in drp expression. Similarly, treatment of low density cells with conditioned media from high density cells fails to elicit drp expression. These results argue that neither soluble factors accumulated or expressed at high density nor simple exit from the cell cycle is sufficient to produce an increase in drp expression. The expression of drp appears to be uniquely regulated by cell density alone. ^

Characterization of a novel CYP19A1 (aromatase) R192H mutation causing virilization of a 46,XX newborn, undervirilization of the 46,XY brother, but no virilization of the mother during pregnancies.

BACKGROUND P450 aromatase (CYP19A1) is essential for the biosynthesis of estrogens from androgen precursors. Mutations in the coding region of CYP19A1 lead to autosomal recessive aromatase deficiency. To date over 20 subjects have been reported with aromatase deficiency which may manifest during fetal life with maternal virilization and virilization of the external genitalia of a female fetus due to low aromatase activity in the steroid metabolizing fetal-placental unit and thus high androgen levels. During infancy, girls often have ovarian cysts and thereafter fail to enter puberty showing signs of variable degree of androgen excess. Moreover, impact on growth, skeletal maturation and other metabolic parameters is seen in both sexes. OBJECTIVE AND HYPOTHESIS We found a novel homozygous CYP19A1 mutation in a 46,XX girl who was born at term to consanguineous parents. Although the mother did not virilize during pregnancy, the baby was found to have a complex genital anomaly at birth (enlarged genital tubercle, fusion of labioscrotal folds) with elevated androgens at birth, normalizing thereafter. Presence of 46,XX karyotype and female internal genital organs (uterus, vagina) together with biochemical findings and follow-up showing regression of clitoral hypertrophy, as well as elevated FSH suggested aromatase deficiency. Interestingly, her older brother presented with mild hypospadias and bilateral cryptorchidism and was found to carry the same homozygous CYP19A1 mutation. To confirm the clinical diagnosis, genetic, functional and computational studies were performed. METHODS AND RESULTS Genetic analysis revealed a homozygous R192H mutation in the CYP19A1 gene. This novel mutation was characterized for its enzymatic activity (Km, Vmax) in a cell model and found to have markedly reduced catalytic activity when compared to wild-type aromatase; thus explaining the phenotype. Computational studies suggest that R192H disrupts the substrate access channel in CYP19A1 that may affect binding of substrates and exit of catalytic products. CONCLUSION R192H is a novel CYP19A1 mutation which causes a severe phenotype of aromatase deficiency in a 46,XX newborn and maybe hypospadias and cryptorchidism in a 46,XY, but no maternal androgen excess during pregnancy.

Fatal contact shot to the chest caused by the gas jet from a muzzle-loading pistol discharging only black powder and no bullet: case study and experimental simulation of the wounding effect.

In modern medico-legal literature, only a small number of publications deal with fatal injuries from black powder guns. Most of them focus on the morphological features such as intense soot soiling, blast tattooing and burn effects in close-range shots or describe the wound ballistics of spherical lead bullets. Another kind of "unusual" and potentially lethal weapons are handguns destined for firing only blank cartridges such as starter and alarm pistols. The dangerousness of these guns is restricted to very close and contact range shots and results from the gas jet produced by the deflagration of the propellant. The present paper reports on a suicide committed with a muzzle-loading percussion pistol cal. 45. An unusually large stellate entrance wound was located in the precordial region, accompanied by an imprint mark from the ramrod and a faint greenish discoloration (apparently due to the formation of sulfhemoglobin). Autopsy revealed an oversized powder cavity, multiple fractures of the anterior thoracic wall as well as ruptures of the heart, the aorta, the left hepatic lobe and the diaphragm. In total, the zone of mechanical destruction had a diameter of approx. 15 cm. As there was no exit wound and no bullet lodged in the body, the injury was caused exclusively by the inrushing combustion gases of the propellant (black powder) comparable with the gas jet of a blank cartridge gun. In contact shots to ballistic gelatine using the suicide's pistol loaded with black powder but no projectile, the formation of a nearly spherical cavity could be demonstrated by means of a high-speed camera. The extent of the temporary cavity after firing with 5 g of black powder roughly corresponded to the zone of destruction found in the suicide's body.

The Conflict between Basescu and Tariceanu – A Governmental System Viewpoint

Semi-presidential systems of democratic governance risk ending up in a stalemate when it is not clear which of the two „heads” – head of State or head of Government – shall take the lead. The current political situation in Romania features some of the commonly observed characteristics of such an institutional blockade. However, after addressing these formal aspects of political Romania, the author argues for not forgetting to take into account the informal, actor-related factors. The nature of the Romanian political parties and party system seems to hinder the finding of a consensus needed to exit the self-imposed blockade. More specifically, it is the Democratic Party (PD) that is the key to understanding the recent developments. The Government of April the third has yet to prove its efficiency.

Laminar and turbulent nozzle-jet flows and their acoustic near-field

We investigate numerically the effects of nozzle-exit flow conditions on the jet-flow development and the near-field sound at a diameter-based Reynolds number of Re D = 18 100 and Mach number Ma = 0.9. Our computational setup features the inclusion of a cylindrical nozzle which allows to establish a physical nozzle-exit flow and therefore well-defined initial jet-flow conditions. Within the nozzle, the flow is modeled by a potential flow core and a laminar, transitional, or developing turbulent boundary layer. The goal is to document and to compare the effects of the different jet inflows on the jet flow development and the sound radiation. For laminar and transitional boundary layers, transition to turbulence in the jet shear layer is governed by the development of Kelvin-Helmholtz instabilities. With the turbulent nozzle boundary layer, the jet flow development is characterized by a rapid changeover to a turbulent free shear layer within about one nozzle diameter. Sound pressure levels are strongly enhanced for laminar and transitional exit conditions compared to the turbulent case. However, a frequency and frequency-wavenumber analysis of the near-field pressure indicates that the dominant sound radiation characteristics remain largely unaffected. By applying a recently developed scaling procedure, we obtain a close match of the scaled near-field sound spectra for all nozzle-exit turbulence levels and also a reasonable agreement with experimental far-field data.

A Plasmodium phospholipase is involved in disruption of the liver stage parasitophorous vacuole membrane

The coordinated exit of intracellular pathogens from host cells is a process critical to the success and spread of an infection. While phospholipases have been shown to play important roles in bacteria host cell egress and virulence, their role in the release of intracellular eukaryotic parasites is largely unknown. We examined a malaria parasite protein with phospholipase activity and found it to be involved in hepatocyte egress. In hepatocytes, Plasmodium parasites are surrounded by a parasitophorous vacuole membrane (PVM), which must be disrupted before parasites are released into the blood. However, on a molecular basis, little is known about how the PVM is ruptured. We show that Plasmodium berghei phospholipase, PbPL, localizes to the PVM in infected hepatocytes. We provide evidence that parasites lacking PbPL undergo completely normal liver stage development until merozoites are produced but have a defect in egress from host hepatocytes. To investigate this further, we established a live-cell imaging-based assay, which enabled us to study the temporal dynamics of PVM rupture on a quantitative basis. Using this assay we could show that PbPL-deficient parasites exhibit impaired PVM rupture, resulting in delayed parasite egress. A wild-type phenotype could be re-established by gene complementation, demonstrating the specificity of the PbPL deletion phenotype. In conclusion, we have identified for the first time a Plasmodium phospholipase that is important for PVM rupture and in turn for parasite exit from the infected hepatocyte and therefore established a key role of a parasite phospholipase in egress.

Mutation in the Monocarboxylate Transporter 12 Gene Affects Guanidinoacetate Excretion but Does Not Cause Glucosuria

A heterozygous mutation (c.643C>A; p.Q215X) in the monocarboxylate transporter 12-encoding gene MCT12 (also known as SLC16A12) that mediates creatine transport was recently identified as the cause of a syndrome with juvenile cataracts, microcornea, and glucosuria in a single family. Whereas the MCT12 mutation cosegregated with the eye phenotype, poor correlation with the glucosuria phenotype did not support a pathogenic role of the mutation in the kidney. Here, we examined MCT12 in the kidney and found that it resides on basolateral membranes of proximal tubules. Patients with MCT12 mutation exhibited reduced plasma levels and increased fractional excretion of guanidinoacetate, but normal creatine levels, suggesting that MCT12 may function as a guanidinoacetate transporter in vivo. However, functional studies in Xenopus oocytes revealed that MCT12 transports creatine but not its precursor, guanidinoacetate. Genetic analysis revealed a separate, undescribed heterozygous mutation (c.265G>A; p.A89T) in the sodium/glucose cotransporter 2-encoding gene SGLT2 (also known as SLC5A2) in the family that segregated with the renal glucosuria phenotype. When overexpressed in HEK293 cells, the mutant SGLT2 transporter did not efficiently translocate to the plasma membrane, and displayed greatly reduced transport activity. In summary, our data indicate that MCT12 functions as a basolateral exit pathway for creatine in the proximal tubule. Heterozygous mutation of MCT12 affects systemic levels and renal handling of guanidinoacetate, possibly through an indirect mechanism. Furthermore, our data reveal a digenic syndrome in the index family, with simultaneous MCT12 and SGLT2 mutation. Thus, glucosuria is not part of the MCT12 mutation syndrome.

Discovery and characterization of a novel non-competitive inhibitor of the divalent metal transporter DMT1/SLC11A2

Divalent metal transporter-1 (SLC11A2/DMT1) uses the H+ electrochemical gradient as the driving force to transport divalent metal ions such as Fe2+, Mn2+ and others metals into mammalian cells. DMT1 is ubiquitously expressed, most notably in proximal duodenum, immature erythroid cells, brain and kidney. This transporter mediates H+-coupled transport of ferrous iron across the apical membrane of enterocytes. In addition, in cells such as to erythroid precursors, following transferrin receptor (TfR) mediated endocytosis; it mediates H+-coupled exit of ferrous iron from endocytic vesicles into the cytosol. Dysfunction of human DMT1 is associated with several pathologies such as iron deficiency anemia hemochromatosis, Parkinson's disease and Alzheimer's disease, as well as colorectal cancer and esophageal adenocarcinoma, making DMT1 an attractive target for drug discovery. In the present study, we performed a ligand-based virtual screening of the Princeton database (700,000 commercially available compounds) to search for pharmacophore shape analogs of recently reported DMT1 inhibitors. We discovered a new compound, named pyrimidinone 8, which mediates a reversible linear non-competitive inhibition of human DMT1 (hDMT1) transport activity with a Ki of ∼20 μM. This compound does not affect hDMT1 cell surface expression and shows no dependence on extracellular pH. To our knowledge, this is the first experimental evidence that hDMT1 can be allosterically modulated by pharmacological agents. Pyrimidinone 8 represents a novel versatile tool compound and it may serve as a lead structure for the development of therapeutic compounds for pre-clinical assessment.

Natural History of Geographic Atrophy Progression Secondary to Age-Related Macular Degeneration (Geographic Atrophy Progression Study).

PURPOSE The Geographic Atrophy Progression (GAP) study was designed to assess the rate of geographic atrophy (GA) progression and to identify prognostic factors by measuring the enlargement of the atrophic lesions using fundus autofluorescence (FAF) and color fundus photography (CFP). DESIGN Prospective, multicenter, noninterventional natural history study. PARTICIPANTS A total of 603 participants were enrolled in the study; 413 of those had gradable lesion data from FAF or CFP, and 321 had gradable lesion data from both FAF and CFP. METHODS Atrophic lesion areas were measured by FAF and CFP to assess lesion progression over time. Lesion size assessments and best-corrected visual acuity (BCVA) were conducted at screening/baseline (day 0) and at 3 follow-up visits: month 6, month 12, and month 18 (or early exit). MAIN OUTCOME MEASURES The GA lesion progression rate in disease subgroups and mean change from baseline visual acuity. RESULTS Mean (standard error) lesion size changes from baseline, determined by FAF and CFP, respectively, were 0.88 (0.1) and 0.78 (0.1) mm(2) at 6 months, 1.85 (0.1) and 1.57 (0.1) mm(2) at 12 months, and 3.14 (0.4) and 3.17 (0.5) mm(2) at 18 months. The mean change in lesion size from baseline to month 12 was significantly greater in participants who had eyes with multifocal atrophic spots compared with those with unifocal spots (P < 0.001) and those with extrafoveal lesions compared with those with foveal lesions (P = 0.001). The mean (standard deviation) decrease in visual acuity was 6.2 ± 15.6 letters for patients with image data available. Atrophic lesions with a diffuse (mean 0.95 mm(2)) or banded (mean 1.01 mm(2)) FAF pattern grew more rapidly by month 6 compared with those with the "none" (mean, 0.13 mm(2)) and focal (mean, 0.36 mm(2)) FAF patterns. CONCLUSIONS Although differences were observed in mean lesion size measurements using FAF imaging compared with CFP, the measurements were highly correlated with one another. Significant differences were found in lesion progression rates in participants stratified by hyperfluorescence pattern subtype. This large GA natural history study provides a strong foundation for future clinical trials.

Modification of aviary design reduces incidence of falls, collisions and keel bone damage in laying hens

Non-cage housing systems for laying hens such as aviaries provide greater freedom to perform species-specific behavior and thus are thought to improve welfare of the birds; however, aviaries are associated with a high prevalence of keel bone damage (fractures and deviations), which is a major welfare problem in commercial laying hens. Potential causes of keel bone damage are falls and collisions with internal housing structures that occur as birds move between tiers or perches in the aviary. The aim of this study was to investigate the scope for reducing keel bone damage by reducing falls and collisions through modifications of aviary design. Birds were kept in 20 pens in a laying hen house (225 hens per pen) that were assigned to four different treatments (n = 5 pens per treatment group) including (1) control pens and pens modified by the addition of (2) perches, (3) platforms and (4) ramps. Video recordings at 19, 22, 29, 36 and 43 weeks of age were used to analyze controlled movements and falls (including details on occurrence of collision, cause of fall, height of fall and behavior after fall) during the transitional dusk and subsequent dark phase. Palpation assessments (focusing on fractures and deviations) using 20 focal hens per pen were conducted at 18, 20, 23, 30, 37, 44, 52 and 60 weeks of age. In comparison to the control group, we found 44% more controlled movements in the ramp (P = 0.003) and 47% more controlled movements in the platform treatments (P = 0.014) as well as 45% fewer falls (P = 0.006) and 59% fewer collisions (P < 0.001) in the ramp treatment. There were no significant differences between the control and perch treatments. Also, at 60 weeks of age, 23% fewer fractured keel bones were found in the ramp compared with the control treatment (P = 0.0053). After slaughter at 66 weeks of age, no difference in keel bone damage was found between treatment groups and the prevalence of fractures increased to an average of 86%. As a potential mechanism to explain the differences in locomotion, we suggest that ramps facilitated movement in the vertical plane by providing a continuous path between the tiers and thus supported more natural behavior (i.e. walking and running) of the birds. As a consequence of reducing events that potentially damage keel bones, the installation of ramps may have reduced the prevalence of keel fractures for a major portion of the flock cycle. We conclude that aviary design and installation of specific internal housing structures (i.e. ramps and platforms) have considerable potential to reduce keel bone damage of laying hens in aviary systems.

MINERALOCORTICOID REGULATION OF ION CONDUCTIVE PATHWAYS OF THE CORTICAL COLLECTING DUCT

Mineralocorticoids (DOCA) are known to increase Na('+) absorption and K('+) secretion in the rabbit cortical collecting duct (CCD). However, the mechanism of regulation of the apical and basolateral cell membranes and tight junction ion conductive pathways (G('a), G('b), and G('tj), respectively) by mineralocorticoids are only partially understood. Using electrophysiological techniques and microelectrodes it was demonstrated that the apical cell membrane contained a dominant Ba('2+) sensitive K('+) conductive pathway, G(,K)('a), and an amiloride sensitive Na('+) conductive pathway, G(,Na)('a). The basolateral membrane contained a dominant Cl('-) conductive pathway, G(,Cl)('b), and a significant Ba('2+) sensitive K('+) conductive pathway, G(,K)('b). Upon elevating the mineralocorticoid levels of rabbits with intact adrenal glands it was found that V('te) was significantly increased after 1 day with a further increase after 13-16 days. These results indicated both primary and secondary effects of mineralocorticoid elevation. After 1 day of DOCA treatment, G(,Na)('a), I(,Na)('a) and I(,K)('a) increased by more than 2-fold and were maintained at high levels after 13-16 days of DOCA treatment. Secondary (chronic) effects of mineralocorticoids were evident after 4 days or more of DOCA treatment. These included a significant increase in G(,K)('a) from 4.0 to 10.2 mS.cm('-2) and a hyperpolarization of V('b) by -20 mV after 4 days of treatment. After 13-16 days of DOCA treatment V('b) remained hyperpolarized at -98.1 mV and G('tj) decreased from 5.6 to 4.2 mS.cm('-2). The hyperpolarization of V('b) was due to an increase in electrogenic Na('+) pump activity as the pump current, I(,act)('b), increased significantly from 35.7 to 195.2 (mu)A.cm('-2). Whereas net passive K('+) current across the basolateral membrane, I(,K)('b), was near zero in the control group of animals, i.e., K('+) near equilibrium, I(,K)('b) was approximately -40 (mu)A.cm('-2) in chronic DOCA treated animals. These results demonstrate that the initial effect of mineralocorticoid elevation is to increase G(,Na)('a). The ensuing depolarization of the apical membrane increases the driving force for K('+) exit into the lumen. Between 1 and 4 days of elevation, G(,K)('a) more than doubles in magnitude and at the same time the electrogenic activity of the Na('+) pump increases. This results in a hyperpolarization of V('b) which increases the driving force for K('+) uptake from the bath to the cell through a basolateral membrane conductive pathway. After 13-16 days G('tj) decreases thereby serving to maintain high electrochemical gradients across the epithelium. Therefore, the long term effects of mineralocorticoid elevation on the CCD appear to be adaptive mechanisms that serve to maintain high levels of K('+) secretion and Na('+) absorption. ^

An 'Ideal' Decomposition of Industry Dynamics: An Application to the Nationwide and State Level U.S. Banking Industry

This paper considers the aggregate performance of the banking industry, applying a modified and extended dynamic decomposition of bank return on equity. The aggregate performance of any industry depends on the underlying microeconomic dynamics within that industry . adjustments within banks, reallocations between banks, entry of new banks, and exit of existing banks. Bailey, Hulten, and Campbell (1992) and Haltiwanger (1997) develop dynamic decompositions of industry performance. We extend those analyses to derive an ideal decomposition that includes their decomposition as one component. We also extend the decomposition, consider geography, and implement decomposition on a state-by-state basis, linking that geographic decomposition back to the national level. We then consider how deregulation of geographic restrictions on bank activity affects the components of the state-level dynamic decomposition, controlling for competition and the state of the economy within each state and employing fixed- and random-effects estimation for a panel database across the fifty states and the District of Columbia from 1976 to 2000.

An 'Ideal' Deconposition of Industry Dynamics: An Application to the Nationwide and State Level U.S. Banking Industry

This paper considers the aggregate performance of the banking industry, applying a modified and extended dynamic decomposition of bank return on equity. The aggregate performance of any industry depends on the underlying microeconomic dynamics within that industry --- adjustments within banks, reallocations between banks, entry of new banks, and exit of existing banks. Bailey, Hulten, and Campbell (1992) and Haltiwanger (1997) develop dynamic decompositions of industry performance. We extend those analyses to derive an ideal dynamic decomposition that includes their dynamic decomposition as one component. We also extend the decomposition, consider geography, and implement decomposition on a state-by-state basis, linking that geographic decomposition back to the national level. We then consider how deregulation of geographic restrictions on bank activity affects the components of the state-level dynamic decomposition, controlling for competition and the state of the economy within each state and employing fixed- and random-effects estimation for a panel database across the fifty states and the District of Columbia from 1976 to 2000.

The Relationship of Student Demographics to 10th Grade MCAS Test Anxiety

The intensification of consequential testing situations is associated with an increase in anxiety among American students (Casbarro, 2005). Test anxiety can have negative effects on student test performance (Everson, Millsap, & Rodriguez, 1991). If test anxiety has the potential to decrease students’ test scores, it becomes a factor that can threaten the validity of any inferences drawn between test scores and student progress (Cizek & Burg, 2006). There are several factors that relate closely to test anxiety (Cizek & Burg, 2006). Variables of key influence include gender, socioeconomic status, and teacher-manifested anxiety (Hembree, 1988). Another influence upon test anxiety is students’ participation in academic support programs to prepare them for exit examinations. The purpose of this study was to examine the relationship between 10th grade high school student gender, socioeconomic status, perceived teacher anxiety, and student preparedness with levels of the Massachusetts Comprehensive Assessment System (MCAS) test anxiety. It appears that few studies have examined levels of high school test anxiety in regards to this specific high-stakes MCAS exit exam required for high school graduation. A two-phase sequential mixed-methods research design was used to survey (N=156) 10th grade students represented by a sampling of (n=80) students with low socioeconomic status and (n=76) students with high socioeconomic status regarding their levels of test anxiety in relation to upcoming MCAS testing. A multiple regression analysis was used to measure the relationship between the predictor variables (gender, socioeconomic status, perceived teacher anxiety, and student preparedness) with the criterion variable of student test anxiety using the Test Anxiety Inventory (TAI). Personal interviews with (n=20) volunteer students provided rich explanations of students’ academic self-efficacy, their perceptions of their performance on the upcoming MCAS exam, and their use of strategies to reduce their levels of test anxiety. Personal interviews with (n=12) volunteer school administrators and teachers provided descriptions of their perceptions of how test anxiety affected their students’ performance. A major quantitative finding of this study was that the variables of student socioeconomic status and student ratings of teacher anxiety accounted for the variance in students’ levels of surveyed test anxiety (R2 = .06, p = .033, small to medium effect size). These results indicate that different student populations vary in their readiness skills to successfully participate in consequential testing situations. Consequently, high-test anxious students would require emotional preparation as well as academic preparation when confronting high-stakes testing. The results have the potential to re-shape the format of schools’ MCAS test preparation efforts.

Verification of intensity modulated stereotactic radiotherapy using Monte Carlo calculations and EPID dosimetry

The purpose of this work was to develop a comprehensive IMSRT QA procedure that examined, using EPID dosimetry and Monte Carlo (MC) calculations, each step in the treatment planning and delivery process. These steps included verification of the field shaping, treatment planning system (RTPS) dose calculations, and patient dose delivery. Verification of each step in the treatment process is assumed to result in correct dose delivery to the patient. ^ The accelerator MC model was verified against commissioning data for field sizes from 0.8 × 0.8 cm 2 to 10 × 10 cm 2. Depth doses were within 2% local percent difference (LPD) in low gradient regions and 1 mm distance to agreement (DTA) in high gradient regions. Lateral profiles were within 2% LPD in low gradient regions and 1 mm DTA in high gradient regions. Calculated output factors were within 1% of measurement for field sizes ≥1 × 1 cm2. ^ The measured and calculated pretreatment EPID dose patterns were compared using criteria of 5% LPD, 1 mm DTA, or 2% of central axis pixel value with ≥95% of compared points required to pass for successful verification. Pretreatment field verification resulted in 97% percent of the points passing. ^ The RTPS and Monte Carlo phantom dose calculations were compared using 5% LPD, 2 mm DTA, or 2% of the maximum dose with ≥95% of compared points required passing for successful verification. RTPS calculation verification resulted in 97% percent of the points passing. ^ The measured and calculated EPID exit dose patterns were compared using criteria of 5% LPD, 1 mm DTA, or 2% of central axis pixel value with ≥95% of compared points required to pass for successful verification. Exit dose verification resulted in 97% percent of the points passing. ^ Each of the processes above verified an individual step in the treatment planning and delivery process. The combination of these verification steps ensures accurate treatment delivery to the patient. This work shows that Monte Carlo calculations and EPID dosimetry can be used to quantitatively verify IMSRT treatments resulting in improved patient care and, potentially, improved clinical outcome. ^