FLASH radiotherapy for the treatment of symptomatic bone metastases in the thorax (FAST-02): protocol for a prospective study of a novel radiotherapy approach.

BACKGROUND: FLASH therapy is a treatment technique in which radiation is delivered at ultra-high dose rates (≥ 40 Gy/s). The first-in-human FAST-01 clinical trial demonstrated the clinical feasibility of proton FLASH in the treatment of extremity bone metastases. The objectives of this investigation are to assess the toxicities of treatment and pain relief in study participants with painful thoracic bone metastases treated with FLASH radiotherapy, as well as workflow metrics in a clinical setting. METHODS: This single-arm clinical trial is being conducted under an FDA investigational device exemption (IDE) approved for 10 patients with 1-3 painful bone metastases in the thorax, excluding bone metastases in the spine. Treatment will be 8 Gy in a single fraction administered at ≥ 40 Gy/s on a FLASH-enabled proton therapy system delivering a single transmission proton beam. Primary study endpoints are efficacy (pain relief) and safety. Patient questionnaires evaluating pain flare at the treatment site will be completed for 10 consecutive days post-RT. Pain response and adverse events (AEs) will be evaluated on the day of treatment and on day 7, day 15, months 1, 2, 3, 6, 9, and 12, and every 6 months thereafter. The outcomes for clinical workflow feasibility are the occurrence of any device issues as well as time on the treatment table. DISCUSSION: This prospective clinical trial will provide clinical data for evaluating the efficacy and safety of proton FLASH for palliation of bony metastases in the thorax. Positive findings will support the further exploration of FLASH radiation for other clinical indications including patient populations treated with curative intent. REGISTRATION: ClinicalTrials.gov NCT05524064.

CD18 dependency of transendothelial neutrophil migration differs during acute pulmonary inflammation.

Neutrophil extravasation during inflammation can occur either by a mechanism that requires the neutrophil integrin complex, CD18, or by an alternative CD18-independent route. Which of the two pathways is used has been shown to depend on the site and nature of the inflammatory insult. More recent evidence suggests that selection may also depend on whether inflammation is chronic or acute, but why this is the case remains unknown. Using an in vitro model that supports both migratory mechanisms, we examined the CD18 dependency of migration of neutrophils isolated from patients with either chronic or acute pulmonary infection. Chronic neutrophils were found to behave like normal neutrophils by migrating to IL-8 and leukotriene B(4) using the CD18-independent pathway, but to the bacterial product, FMLP, using the CD18-dependent route. In contrast, migration of acute neutrophils to all of these stimuli was CD18 dependent. Normal neutrophils could be manipulated to resemble acute neutrophils by exposing them to FMLP before migration, which resulted in a "switch" from the CD18-independent to -dependent mechanism during migration to IL-8 or leukotriene B(4). Although treatment of normal neutrophils with FMLP caused selective down-regulation of the IL-8 receptor, CXCR2, and acute neutrophils were found to have less CXCR2 than normal, a functional relationship between decreased CXCR2 and selection of CD18-dependent migration was not demonstrated. Results indicate that selection of the CD18-dependent or -independent migration mechanism can be controlled by the neutrophil and suggest that the altered CD18 requirements of acute neutrophils may be due to priming in the circulation during acute infection.

Utilisation of nutrients by embryos of the enigmatic Australian viviparous skink Niveoscincus coventryi.

The Eugongylus species group of Australian lygosomine skinks provides an unparalleled opportunity to study the evolution of placentotrophy. Viviparity and placentotrophy have evolved in two lineages, currently recognised as the genera Pseudemoia and Niveoscincus. The genus Niveoscincus is important because it is the only lineage of squamates in which variation in placental morphology and in the pattern of embryonic nutrition is known. Niveoscincus coventryi has the least complex placental morphology among species currently assigned to the genus. We quantified the net uptake of nutrients across the placenta of N. coventryi for comparison with other species in the genus and with other viviparous and oviparous lizards. The pattern of embryonic nutrition of N. coventryi is similar to other viviparous lizards with simple placentae in that there is no net uptake of dry matter during development but there is a net uptake of water, calcium, potassium, and sodium. There is no net uptake of lipid, nitrogen (an index of protein), or magnesium. We conclude that N. coventryi is predominantly lecithotrophic. Further, if N. coventryi is the sister taxon to Tasmanian Niveoscincus, then the distribution of patterns of embryonic nutrition among members of this clade suggests that the evolution of placentotrophy occurred during radiation of this lineage in Tasmania.

Nutrient uptake by embryos of the Australian viviparous lizard Eulamprus tympanum.

Eulamprus tympanum is a high-altitude viviparous lizard that was probably used to help define a Type I chorioallantoic placenta. In this article, we (1) describe the net transport of nutrients across the placenta of E. tympanum, and (2) compare placental uptake in E. tympanum with a previous study of Eulamprus quoyii, which occurs in warmer environments, to assess the potential importance of thermal regime on placentotrophy. Freshly ovulated eggs are 387.3+/-19.7 mg. There is a significant net uptake of water and a net loss of dry matter during development, so the dry neonate is only 84% the size of the dry egg. There is no significant change in the total ash or nitrogen in eggs during embryonic development, with the entire loss of dry matter being lipid. Almost the entire loss of lipid occurs in the triacylglycerol fraction, with no net change in phospholipids. A net increase in total cholesterol suggests that cholesterol is synthesised by the developing embryo. The lipid profile of eggs of E. tympanum reflects that of other species with simple placentae in having a relatively high proportion of triacylglycerol and little cholesterol. The fatty acid composition of eggs reflects that expected in the diet of E. tympanum. There is a preservation and some synthesis of arachidonic (20:4n-6) and docosahexaenoic (22:6n-3) acids in the phospholipid fraction during embryonic development. Despite there being no net uptake of ash, there is a net increase in calcium, potassium, sodium, and magnesium in the neonate compared with the egg. We conclude that E. tympanum, like E. quoyii, is predominantly lecithotrophic with little, if any, uptake of organic molecules but with significant uptake of some inorganic ions and water. In addition, there is no difference in placentotrophy correlated with differences in the environments inhabited by each species.

Utilisation of lipids, protein, ions and energy during embryonic development of Australian oviparous skinks in the genus Lampropholis.

The contents of eggs and neonates of the Australian skinks, Lampropholis guichenoti and L. delicata, are described and compared to allow interpretation of nutrient utilisation by the developing embryo. Even though the females are the same size, L. guichenoti lay smaller clutches of larger eggs (egg contents=41.6+/-1.2 mg dry mass) than L. delicata (26.6+/-2.8 mg). The energy density is the same for eggs (30.5+/-0.9 J/g ash-free dry mass for L. guichenoti and 29.9+/-1.1 J/mg for L. delicata) and neonates (22.5+/-1.3 J/mg for L. guichenoti and 23.5+/-0.4 J/mg for L. delicata) between species. The amount of nitrogen (protein) in neonates is only slightly lower than that in eggs, whereas there is a large and significant decline in total lipids. Thus, like some other skinks, protein is a source of metabolic energy during embryogenesis, although not as important as lipid. Triacylglycerol is the major lipid component of the eggs (80% of total lipid), with phospholipid forming only approximately 10% of the total lipid. The fatty acid profile of the phospholipid is distinguished by a high proportion of arachidonic acid (8%), a significant proportion of eicosapentaenoic acid (2-4%) and a relatively low proportion of docosahexaenoic acid (2-3%) compared to chickens. Eggs of both species have remarkably low concentrations of free cholesterol compared to other amniote eggs (0.7% for L. guichenoti and 1.3% for L. delicata). The loss of lipid during embryonic development is almost entirely due to the selective utilisation of yolk triacylglycerol, presumably for energy. By contrast, the amount of phospholipid recovered from the neonates was the same as that originally in the eggs. Moreover, significantly more total cholesterol was present in the neonates than in the eggs, suggesting that biosynthesis of additional cholesterol occurred during development. The phospholipids of the neonates contain higher proportions of arachidonic (11-12%) and docosahexaenoic (8%) acids than the phospholipids of the eggs. Eicosapentaenoic acid is less prevalent in phospholipids in neonates than in eggs. Neonates of both species contain significantly more calcium than the fresh egg contents (L. guichenoti, eggs 0.303+/-0.051 mg, neonates 0.641+/-0.047 mg; L. delicata, eggs 0.187+/-0.013 mg, neonates 0.435+/-0.033 mg), presumably as a result of resorption of calcium from the eggshell. Interestingly, there is also significantly more sodium in neonates than in the contents of fresh eggs (L. guichenoti, eggs 0.094+/-0.010 mg, neonates 0.184+/-0.011 mg; L. delicata, eggs 0.084+/-0.011 mg, neonates 0.151+/-0.010 mg). There is no significant difference in the content of potassium and magnesium in eggs and neonates of either species. Although the fresh eggs of L. delicata have a significantly higher sodium concentration than L. guichenoti, there is no difference in the concentrations of calcium, magnesium, potassium or sodium in the neonates of the two species.

Placental nutrition in the Tasmanian skink, Niveoscincus ocellatus.

Niveoscincus ocellatus is an important species in historical analyses of the evolution of viviparity because it is the species upon which the type II chorioallantoic placenta was based. Here we describe the net nutrient uptake across the placenta of N. ocellatus for comparison with other species of skinks with complex placentae. N. ocellatus is highly placentotrophic, with neonates being 1.68-times larger in dry matter than the fresh eggs. There is an increase of nitrogen from 6.3 +/- 0.2 mg to 9.2 +/- 0.6 mg, and ash from 3.8 +/- 0.3 mg to 6.7 +/- 0.6 mg. The increase in ash is made up by a more than two-fold increase in the amounts of calcium, potassium and sodium. There is no significant difference in lipids in the neonates compared to fresh eggs, so considerable lipid must have crossed the placenta to provide energy for embryonic development. N. ocellatus is significantly more placentotrophic than Niveoscincus metallicus, which also has a complex chorioallantoic placenta. Discovery of substantial placentotrophy in this genus confirms that two lineages of Australian lygosomine skinks (represented by the genera Pseudemoia and Niveoscincus) have evolved this pattern of embryonic nutrition and supports the hypothesis that the evolution of reptilian placentotrophy involves specialisations in addition to structural modifications of the chorioallantoic placenta.

Evidence for the expression of radiation-induced potentially lethal damage being a p53-dependent process.

PURPOSE: To test the hypothesis that the expression of potentially lethal damage (PLD) is a p53-dependent process. MATERIALS AND METHODS: Previously reported data on radiation sensitivity, DNA double-strand break rejoining, PLD expression and repair (PLDR) were analyzed for a group of 12 human tumor cell lines and three human diploid fibroblast cell lines. Seven of these cell lines had normal p53 gene expression while the other eight were functionally p53-deficient. None of the cell lines was sensitive to radiation-induced apoptosis. RESULTS: Cell lines with a normal p53 expression were more sensitive to radiation, but only when sensitivity was measured in plateau-phase cultures under conditions where PLDR was minimized. Mutation or functional inactivation of p53 by HPV E6-transformation led to a more radioresistant phenotype under these conditions as well as a significant reduction in PLDR. PLDR was inversely proportional to the percentage of radiation-induced DNA double-strand breaks rejoined in 1 h in the p53 normal cell lines. CONCLUSIONS: These results suggest that the expression of PLD is primarily a p53-dependent process. In the absence of functional p53 gene expression, the effects of PLD are minimized. These observations help clarify the role of p53 in tumor response to radiation therapy because they suggest that the effects of alterations in p53 are highly dependent on the microenvironment of the tumor, i.e. whether conditions allow for PLDR.

Interleukin-8 and leukotriene-B(4), but not formylmethionyl leucylphenylalanine, stimulate CD18-independent migration of neutrophils across human pulmonary endothelial cells in vitro.

Although neutrophil migration from the systemic circulation involves the beta2- (or CD18) integrin family, the existence of an alternative, CD18-independent route of neutrophil extravasation to tissues has been demonstrated in animal models. The molecular interactions involved in this alternative migratory route have not yet been characterized. The objective of this study was to assess the CD18-dependency of neutrophil migration across human endothelial cells from an organ known to support CD18-independent migration, the lung, with a view to establishing an in vitro model to facilitate study of CD18-independent migration. Neutrophil migration across human pulmonary artery endothelial cells (HPAECs) in response to three different chemoattractants, formylmethionyl leucylphenyl-alanine (FMLP), interleukin (IL)-8, and leukotriene (LT) B(4), was examined. Results demonstrated that a function-blocking antibody to CD18 decreased FMLP-stimulated migration by 71.7 +/- 4.4% (P < 0.001). In contrast, migration in response to LTB(4) was decreased by only 20.5 +/- 10.2% (P < 0.01), and no significant decrease was observed with migration to IL-8. Neutrophils that migrated to FMLP had 1.7-fold more surface CD11b/CD18 compared with nonmigrated neutrophils (P < 0.01), whereas this integrin complex was not significantly upregulated on neutrophils that had migrated to IL-8 or LTB(4). Further investigation of this migratory route indicated that it did not involve the beta1 integrins (CD29) or the endothelial selectins, E- or P-selectin, nor did it require the activity of either metalloproteinases or neutrophil elastase. These results indicate that neutrophil migration across HPAECs in vitro to IL-8 and LTB(4) is predominantly CD18-independent and provides a much-needed in vitro system for examination of the neutrophil-endothelial interactions involved in this alternative migratory route.

Preliminary report of toxicity following 3D radiation therapy for prostate cancer on 3DOG/RTOG 9406.

PURPOSE: A prospective Phase I dose escalation study was conducted to determine the maximally-tolerated radiation dose in men treated with three-dimensional conformal radiation therapy (3D CRT) for localized prostate cancer. This is a preliminary report of toxicity encountered on the 3DOG/RTOG 9406 study. METHODS AND MATERIALS: Each participating institution was required to implement data exchange with the RTOG 3D quality assurance (QA) center at Washington University in St. Louis. 3D CRT capabilities were strictly defined within the study protocol. Patients were registered according to three stratification groups: Group 1 patients had clinically organ-confined disease (T1,2) with a calculated risk of seminal vesicle invasion of < 15%. Group 2 patients had clinical T1,2 disease with risk of SV invasion > or = 15%. Group 3 (G3) patients had clinical local extension of tumor beyond the prostate capsule (T3). All patients were treated with 3D techniques with minimum doses prescribed to the planning target volume (PTV). The PTV margins were 5-10 mm around the prostate for patients in Group 1 and 5-10 mm around the prostate and SV for Group 2. After 55.8 Gy, the PTV was reduced in Group 2 patients to 5-10 mm around the prostate only. Minimum prescription dose began at 68.4 Gy (level I) and was escalated to 73.8 Gy (level II) and subsequently to 79.2 Gy (level III). This report describes the acute and late toxicity encountered in Group 1 and 2 patients treated to the first two study dose levels. Data from RTOG 7506 and 7706 allowed calculation of the expected probability of observing a > or = grade 3 late effect more than 120 days after the start of treatment. RTOG toxicity scores were used. RESULTS: Between August 23, 1994 and July 2, 1997, 304 Group 1 and 2 cases were registered; 288 cases were analyzable for toxicity. Acute toxicity was low, with 53-54% of Group 1 patients having either no or grade 1 toxicity at dose levels I and II, respectively. Sixty-two percent of Group 2 patients had either none or grade 1 toxicity at either dose level. Few patients (0-3%) experienced a grade 3 acute bowel or bladder toxicity, and there were no grade 4 or 5 toxicities. Late toxicity was very low in all patient groups. The majority (81-85%) had either no or mild grade 1 late toxicity at dose level I and II, respectively. A single late grade 3 bladder toxicity in a Group 2 patient treated to dose level II was recorded. There were no grade 4 or 5 late effects in any patient. Compared to historical RTOG controls (studies 7506, 7706) at dose level I, no grade 3 or greater late effects were observed in Group 1 and Group 2 patients when 9.1 and 4.8 events were expected (p = 0.003 and p = 0.028), respectively. At dose level II, there were no grade 3 or greater toxicities in Group 1 patients and a single grade 3 toxicity in a Group 2 patient when 12.1 and 13.0 were expected (p = 0.0005 and p = 0.0003), respectively. Multivariate analysis demonstrated that the relative risk of developing acute bladder toxicity was 2.13 if the percentage of the bladder receiving > or = 65 Gy was more than 30% (p = 0.013) and 2.01 if patients received neoadjuvant hormonal therapy (p = 0.018). The relative risk of developing late bladder complications also increased as the percentage of the bladder receiving > or = 65 Gy increased (p = 0.026). Unexpectedly, there was a lower risk of late bladder complications as the mean dose to the bladder and prescription dose level increased. This probably reflects improvement in conformal techniques as the study matured. There was a 2.1 relative risk of developing a late bowel complication if the total rectal volume on the planning CT scan exceeded 100 cc (p = 0.019). CONCLUSION: Tolerance to high-dose 3D CRT has been better than expected in this dose escalation trial for Stage T1,2 prostate cancer compared to low-dose RTOG historical experience. With strict quality assurance standards and review, 3D CRT can be safely studied in a co

Migration of neutrophils across human pulmonary endothelial cells is not blocked by matrix metalloproteinase or serine protease inhibitors.

It has long been speculated that neutrophils deploy proteases to digest subendothelial matrix as they migrate from the bloodstream. Direct evidence for the involvement of proteases in neutrophil transendothelial migration is, however, lacking. To address this issue we used transmission electron microscopy to verify the presence of continuous basal lamina beneath pulmonary endothelial cells grown on microporous filters, and then examined the effects of protease inhibitors on neutrophil migration through the endothelial cells and their associated subcellular matrix. Inhibitors of the two major matrix-degrading protease groups present in neutrophils, the matrix metalloproteinases (MMPs) and serine proteases, were assessed for their ability to modulate neutrophil transendothelial migration in response to the chemoattractant n-formylmethionyl leucylphenylalanine (FMLP). Neither the naturally occurring MMP inhibitor, tissue inhibitor of metalloproteinase-1, nor the hydroxamic acid-based inhibitors GM-6001, BB-3103, or Ro 31-9790 had any significant effect on FMLP-stimulated neutrophil migration across endothelial cells and associated basal lamina, with >/= 80% of neutrophils migrating through the system, even in the presence of inhibitors, at concentrations that totally inhibited all the gelatinase B (MMP-9) released upon stimulation with FMLP. Similarly, with serine protease inhibitors no significant inhibition of neutrophil migration was observed with a naturally occurring inhibitor, secretory leukocyte protease inhibitor, or a low molecular-weight synthetic inhibitor, Pefabloc SC. These results indicate that neither MMP nor serine protease digestion of sub-endothelial matrix is required for successful neutrophil transendothelial migration.

Functional inactivation of p53 by HPV-E6 transformation is associated with a reduced expression of radiation-induced potentially lethal damage.

PURPOSE: To examine the effect of functional loss of p53 on radiation sensitivity and potentially lethal damage repair (PLDR). MATERIALS AND METHODS: Radiation sensitivity and PLDR were examined in an isogenic pair of human tumour cell lines created by HPV-E6 transformation. RESULTS: Inactivation of p53 by E6 transformation resulted in a cell line that was more resistant to killing by radiation but showed little enhancement in survival (PLDR) when plateau-phase cells were held non-cycling after radiation exposure. Holding p53-normal cells in plateau-phase after radiation exposure not only led to enhanced survival, but also to a reduction in the proportion of cells that blocked in G1 subsequent to release. CONCLUSIONS: These results suggest that p53 expression influences that component of radiation sensitivity associated with PLDR.

The effect of functional inactivation of TP53 by HPV-E6 transformation on the induction of chromosome aberrations by gamma rays in human tumor cells.

The influence of expression of TP53 (formerly known as p53) on the induction of chromosome aberrations by gamma rays was examined in an isogenic pair of human tumor cell lines where TP53 expression was normal or inactivated by human papillomavirus (HPV) type 16 E6 expression. Plateau-phase cultures were exposed to 0-8 Gy gamma rays and then either immediately released by subculture or held for 24 h prior to subculture and subsequent cytogenetic analysis. Aberration frequency was determined only in cells entering their first mitosis after irradiation, and cells were sampled over a 48-h period to include cells whose progression into mitosis was delayed. While aberration frequencies were similar at early harvest times, there was evidence for a subpopulation of more heavily damaged cells in the E6-transformed cells that cycled into late mitosis. Holding cells noncycling for 24 h to allow repair of potentially lethal damage eliminated this subpopulation of more heavily damaged cells. The E6-transformed cells also had higher levels of chromatid-type aberrations and sister chromatid exchanges, consistent with an additional defect in kinetics of repair of base damage that is associated with the E6 transformation. Holding cells noncycling for 24 h eliminated the elevated levels of chromatid-type aberrations and sister chromatid exchanges. These studies demonstrate that E6 transformation of human tumor cells will influence both the frequency and types of chromosome aberrations observed after radiation exposure, and that these effects are related to the expression of potentially lethal damage.

Can general practitioner referral letters for acute medical admissions be improved?

BACKGROUND: General practitioner (GP) referral letters for emergency medical admissions should contain enough information to ensure that patients are managed safely and effectively. AIM: Our aim was to assess the quality of referral letters for acute medical admissions. METHOD: GP letters from 300 consecutive acute medical admissions were prospectively assessed by the admitting doctor and then independently assessed by a senior house officer (SHO), and a senior registrar. A random sample of 25 were assessed by a general practitioner. Content and legibility were evaluated for demographic details, current history, past history, social history, drugs and allergies, in order to grade the overall quality as "excellent", "good", "adequate" or "inadequate". RESULTS: Two hundred and ninety one letters were received, of which 208 (71%) were from the patients' own GP practice and 83 (28%) from a co-operative or deputising service. The admitting doctor rated 38 (13%) as excellent, 108 (37%) as good, 96 (33%) as adequate and 49 (17%) as inadequate. Kappa values for overall quality between the admitting doctors and the other doctors (senior house officer, senior registrar and our general practitioner) were 0.32, 0.26 and 0.44 respectively, representing fair to moderate interobserver agreement. Co-operatives or deputising services used proformas more often than GP practices (65/83, 78% and 17/208, 8% respectively, p < 0.01). There was no significant difference in overall quality between GP practices and co-operatives or deputising services, or between letters received on headed note paper or proformas. CONCLUSION: Most letters are satisfactory for the individual management of acutely ill patients, but collaborative work could usefully be undertaken to address the factors which result in the production of sub-optimal referral letters.

Fast neutrons in prostatic adenocarcinomas: worldwide clinical experience.

Primary tumor control remains a major problem in the treatment of locally advanced prostate carcinoma. Clinical local failure rates approach 30-40% and may be significantly higher when results of prostatic biopsy or prostate-specific antigen (PSA) levels are considered. The low growth rate and cycling fraction of prostate adenocarcinoma suggest potential therapeutic advantage for the high linear energy transfer (LET) of neutrons. The Radiation Therapy Oncology Group (RTOG) performed a multi-institutional randomized trial (RTOG 77-04) comparing mixed beam (neutron plus photon) irradiation to conventional photon irradiation for the treatment of locally advanced prostate cancer. A subsequent trial by the Neutron Therapy Collaborative Working Group (NTCWG 85-23) compared pure neutron irradiation to standard photon irradiation. Both randomized trials demonstrate significant improvement in locoregional control with neutron irradiation compared to conventional photon irradiation in the treatment of locally advanced prostate carcinoma. To date, only the mixed beam trial has shown a significant survival benefit. Future analysis of the larger NTCWG trial at the 10-year point should confirm whether or not improved locoregional control translates into a survival advantage. These findings have significant implications for all local treatment strategies including dose-escalated conformal photon irradiation, prostate implantation, and neutron radiation. Given the large numbers of patients afflicted with this disease, a positive survival advantage for neutrons or mixed beam therapy would provide a strong incentive for the development of economically feasible clinical neutron facilities.

Neutron beam radiotherapy for recurrent prostate cancer following radical prostatectomy.

PURPOSE: To evaluate the effectiveness of neutron beam radiotherapy (NXRT) to treat recurrent prostate cancer following radical prostatectomy (RP). METHODS AND MATERIALS: Twenty-five patients who failed RP received NXRT at our institution. The pathological stages ranged from T2c-T3c, with 16 patients having either seminal vesicle involvement and/or nodal metastases. Sixteen patients also received neoadjuvant hormones. Freedom from relapse (FFR) was defined by an undetectable PSA (PSA < or =0.2). Median follow-up was 27 months, with no patients lost to follow-up. RESULTS: Postneutron PSA became initially undetectable in 84% of patients. The actuarial FFR is 36% at 3 years. Nine patients remain NED, 12 patients have an elevated PSA only, 2 patients have clinical recurrence, and 2 patients are dead of prostate cancer. Pre-NXRT PSA levels of < or =1.0 vs. >1.0 predicted for outcome, with a FFR at 3 years of 76 vs. 14% (p = 0.003). Patients with a persistently elevated PSA following RP were not effectively salvaged by NXRT, with a 12% FFR at 3 years compared to a 62% FFR for patients whose PSA initially normalized following RP (p = 0.03). There was no difference in treatment outcomes based on fields encompassing pelvic nodes vs. fields directed to the prostatic fossa only. There were no severe (RTOG Grade 3) late complications. CONCLUSION: NXRT is an effective salvage treatment for carefully selected patients. This group includes patients whose PSA initially normalized following RP, and whose pre-NXRT PSA < or =1.0.

Neutrophil adhesion molecule surface expression and responsiveness in cystic fibrosis.

The neutrophil-dominated inflammation of the lung in cystic fibrosis (CF) has traditionally been seen as a physiological response to continuous opportunistic infection. Recent studies suggest, however, that regulation of the inflammatory response itself may be altered in CF. Neutrophil migration from the bloodstream involves alterations in surface expression of the adhesion molecules L-selectin and Mac-1 (CD11b/CD18). The aim of this study was to assess neutrophil adhesion molecule expression and responsiveness in CF. Neutrophils from chronic (n = 16) and acutely infected (n = 13) CF patients and 15 normal control subjects were directly assessed by Fluorescence-activated cell sorter (FACS) analysis for surface expression of L-selectin and CD11b before and after stimulation with interleukin 8 (IL-8) or f-Met-Leu-Phe (fMLP). Neutrophils from stable (n = 5) and acutely infected (n = 5) non-CF bronchiectasis patients were also assessed. Surface upregulation of CD11b was similar in all groups. Basal levels of L-selectin were also comparable among all groups, however, when stimulated, neutrophils from both stable and acutely infected CF patients shed significantly less L-selectin than those from control subjects (p < 0.05 and p < 0.01, respectively). This decreased responsiveness was not observed in either stable or acutely infected non-CF bronchiectasis patients. These results add to the accumulating evidence suggestive of a defective inflammatory response in CF.

Matrix metalloproteinase expression and production by alveolar macrophages in emphysema.

The aim of this study was to examine the hypothesis that alveolar macrophages represent a significant source of matrix-degrading proteinases in the emphysematous lung. Macrophages from bronchoalveolar lavage fluid of 10 patients with emphysema and 10 normal volunteers were maintained in vitro for 24 h and assessed semiquantitatively for mRNA transcript levels of the matrix metalloproteinases (MMPs) gelatinases A and B, macrophage metalloelastase (MME), and interstitial collagenase. Release of these MMPs into the culture medium and secretion of neutrophil elastaselike activity was also assessed. Elevated levels of mRNA transcripts for gelatinase B (p < 0.0005) and interstitial collagenase (p < 0.0005) were observed in macrophages from emphysematous patients. Increased collagenase (p < 0.01) and neutrophil elastaselike activities (p < 0.001) were also measured in conditioned medium from patient macrophages. With gelatinase B, complexed forms of the enzyme were secreted by patient but not by control macrophages. No difference in transcript levels of gelatinase A or MME was observed between patient and control samples, and neither enzyme was detected in macrophage-conditioned media from either group. These results directly demonstrate that alveolar macrophages from the emphysematous lung produce elevated quantities of matrix-degrading enzymes with both elastolytic and collagenolytic activities.

Elevated levels of matrix metalloproteinases in bronchoalveolar lavage fluid of emphysematous patients.

BACKGROUND: Matrix degradation in emphysema has long been attributed to the action of neutrophil elastase (NE). More recently a role for other proteases, particularly the matrix metalloproteinases (MMPs), in the pathogenesis of this disease has been proposed. To date, however, the presence of MMPs in the lungs of patients with emphysema has not been demonstrated. METHODS: Samples of bronchoalveolar lavage (BAL) fluid from 10 patients with emphysema and from control subjects matched for sex and current smoking status were assessed for collagenase, gelatinase, and NE activity. Pulmonary function tests and computed tomographic (CT) scans were carried out on all study subjects. RESULTS: Collagenase activity was detected in BAL fluid samples from all emphysematous patients but in only one smoking control (p < 0.001). Gelatinase B was present in six patients and in two smoking controls (p < 0.03). The concomitant presence of gelatinase B in complex with lipocalin (NGAL) in the gelatinase positive samples suggests that the neutrophil is a significant source of the gelatinase B observed. NE was detected in six of the 10 patients with emphysema and in two smoking controls (p < 0.01), indicating that collagenase was more useful in discriminating between disease and control groups than either NE or gelatinase B. No relationship was observed between any of the enzymes measured and pulmonary function or CT density score. CONCLUSIONS: This study demonstrates, for the first time, the presence of increased levels of matrix metalloproteinases in the lungs of patients with emphysema and suggests that, in BAL fluid, collagenase activity may be a better indicator of the presence of emphysema than elastase.

Preferential radiosensitization of G1 checkpoint-deficient cells by methylxanthines.

PURPOSE: To develop a checkpoint-based strategy for preferential radiosensitization of human tumors with deficient and/or mutant p53. METHODS AND MATERIALS: A549 human lung adenocarcinoma cell lines differing in their expression of the p53 tumor suppressor gene were produced by transduction with the E6 oncogene from human papilloma virus type 16. The cells expressing E6 (E6+) lack a G1 arrest in response to ionizing radiation, are deficient in p53 and p21 expression, and exhibit a fivefold greater clonogenic survival following 10 Gy radiation. RESULTS: Postirradiation incubation with millimolar concentrations of the methylxanthine pentoxifylline (PTX) results in preferential radiosensitization of the E6+ cells compared to the LXSN+ vector transduced controls. There is a threefold sensitization of the LXSN+ cells and a 15-fold sensitization of the E6+ cells, which results in equal clonogenic survival of the two lines. Flow cytometry reveals PTX abrogation of the radiation induced G2 arrest for both cell lines. PTX also prolongs G1 transit for both cell lines. Preliminary results are presented using a novel methylxanthine, lisofylline (LSF), which has similar cell cycle effects on G1 and G2 and achieves differential radiosensitization at micromolar concentrations that are sustainable in humans. CONCLUSION: This checkpoint-based strategy is a promising approach for achieving preferential radiosensitization of p53- tumors relative to p53+ normal tissues.

Clinical trials of neutron radiotherapy in the United States.

The development of clinical neutron facilities in the 1980s, capable of delivering high energy neutrons spurred full scale phase III testing of neutron beam radiotherapy in a number of tumors including salivary gland, head and neck, prostate, and non small-cell lung cancer. The Radiation Therapy Oncology Group (RTOG) and the Medical Research Council (MRC) jointly sponsored a randomized trial for the treatment of advanced stage salivary gland tumors comparing neutron to conventional photon and/or electron radiotherapy. Although no improvement in survival was seen, the study demonstrated a striking and statistically significant difference in the local-regional control of unresectable salivary gland tumors (56 vs 17%), favoring neutron beam irradiation. Subsequent clinical trials of neutron beam irradiation were initiated by the Neutron Therapy Collaborative Working Group (NTCWG) sponsored by the National Cancer Institute (NCI). A phase III trial comparing neutron to photon radiotherapy for inoperable regional non-small cell lung cancer showed no overall improvement in survival. However, a statistically significant improvement in survival was observed in the subset of patients with squamous cell histology. The NTCWG trial comparing fast-neutron therapy versus conventional photon irradiation in the treatment of advanced squamous cell carcinomas of the head and neck showed a statistically significant improvement in initial complete response (70 vs 52%) favoring neutrons. However, subsequent failures erased any difference in ultimate local-regional control rates and survival curves were essentially the same in both arms. The randomized study of the NTCWG for locally advanced prostate cancer demonstrated a significant decrease in local-regional failure (11 vs 32%) at 5 years, favoring the neutron arm. Furthermore, biochemical measures of disease control also favored the neutron arm with prostate specific antigen (PSA) levels elevated in 17% of the neutron-treated patients compared to 45% of the photon-treated patients at 5 years. At the 5-year analysis, no significant difference in survival was observed between the two arms; however, longer follow-up is necessary to assess the ultimate impact of improved local-regional control on survival. An analysis of complications in this series revealed the importance of beam shaping and treatment planning capabilities in maintaining long-term sequelae following neutron irradiation at an acceptably low level.