56 Fe ion exposure increases the incidence of lung and brain tumors at a similar rate in male and female mice.

The main deterrent to long-term space travel is the risk of Radiation Exposure Induced Death (REID). The National Aeronautics and Space Administration (NASA) has adopted Permissible Exposure Levels (PELs) to limit the probability of REID to 3% for the risk of death due to radiation-induced carcinogenesis. The most significant contributor to current REID estimates for astronauts is the risk of lung cancer. Recently updated lung cancer estimates from Japan's atomic bomb survivors showed that the excess relative risk of lung cancer by age 70 is roughly four-fold higher in females compared to males. However, whether sex differences may impact the risk of lung cancer due to exposure to high charge and energy (HZE) radiation is not well studied. Thus, to evaluate the impact of sex differences on the risk of solid cancer development post-HZE radiation exposure, we irradiated Rb fl/fl ; Trp53 fl/+ male and female mice infected with Adeno-Cre with various doses of 320 kVp X-rays or 600 MeV/n 56 Fe ions and monitored them for any radiation-induced malignancies. We observed that lung adenomas/carcinomas and esthesioneuroblastomas (ENBs) were the most common primary malignancies in X-ray and 56 Fe ion-exposed mice, respectively. In addition, 1 Gy 56 Fe ion exposure compared to X-rays led to a significantly higher incidence of lung adenomas/carcinomas (p=0.02) and ENBs (p<0.0001). However, we did not find a significantly higher incidence of any solid malignancies in female mice as compared to male mice, regardless of radiation quality. Furthermore, gene expression analysis of ENBs suggested a distinct gene expression pattern with similar hallmark pathways altered, such as MYC targets and MTORC1 signaling, in X-ray and 56 Fe ion-induced ENBs. Thus, our data revealed that 56 Fe ion exposure significantly accelerated the development of lung adenomas/carcinomas and ENBs compared to X-rays, but the rate of solid malignancies was similar between male and female mice, regardless of radiation quality.

Bleeding Risk With Combination Intrapleural Fibrinolytic and Enzyme Therapy in Pleural Infection: An International, Multicenter, Retrospective Cohort Study.

BACKGROUND: Combination intrapleural fibrinolytic and enzyme therapy (IET) has been established as a therapeutic option in pleural infection. Despite demonstrated efficacy, studies specifically designed and adequately powered to address complications are sparse. The safety profile, the effects of concurrent therapeutic anticoagulation, and the nature and extent of nonbleeding complications remain poorly defined. RESEARCH QUESTION: What is the bleeding complication risk associated with IET use in pleural infection? STUDY DESIGN AND METHODS: This was a multicenter, retrospective observational study conducted in 24 centers across the United States and the United Kingdom. Protocolized data collection for 1,851 patients treated with at least one dose of combination IET for pleural infection between January 2012 and May 2019 was undertaken. The primary outcome was the overall incidence of pleural bleeding defined using pre hoc criteria. RESULTS: Overall, pleural bleeding occurred in 76 of 1,833 patients (4.1%; 95% CI, 3.0%-5.0%). Using a half-dose regimen (tissue plasminogen activator, 5 mg) did not change this risk significantly (6/172 [3.5%]; P = .68). Therapeutic anticoagulation alongside IET was associated with increased bleeding rates (19/197 [9.6%]) compared with temporarily withholding anticoagulation before administration of IET (3/118 [2.6%]; P = .017). As well as systemic anticoagulation, increasing RAPID score, elevated serum urea, and platelets of < 100 × 109/L were associated with a significant increase in bleeding risk. However, only RAPID score and use of systemic anticoagulation were independently predictive. Apart from pain, non-bleeding complications were rare. INTERPRETATION: IET use in pleural infection confers a low overall bleeding risk. Increased rates of pleural bleeding are associated with concurrent use of anticoagulation but can be mitigated by withholding anticoagulation before IET. Concomitant administration of IET and therapeutic anticoagulation should be avoided. Parameters related to higher IET-related bleeding have been identified that may lead to altered risk thresholds for treatment.

Radiosensitizing the Vasculature of Primary Brainstem Gliomas Fails to Improve Tumor Response to Radiation Therapy.

PURPOSE: Diffuse intrinsic pontine gliomas (DIPGs) arise in the pons and are the leading cause of death from brain tumors in children. DIPGs are routinely treated with radiation therapy, which temporarily improves neurological symptoms but generally fails to achieve local control. Because numerous clinical trials have not improved survival from DIPG over standard radiation therapy alone, there is a pressing need to evaluate new therapeutic strategies for this devastating disease. Vascular damage caused by radiation therapy can increase the permeability of tumor blood vessels and promote tumor cell death. METHODS AND MATERIALS: To investigate the impact of endothelial cell death on tumor response to radiation therapy in DIPG, we used dual recombinase (Cre + FlpO) technology to generate primary brainstem gliomas which lack ataxia telangiectasia mutated (Atm) in the vasculature. RESULTS: Here, we show that Atm-deficient tumor endothelial cells are sensitized to radiation therapy. Furthermore, radiosensitization of the vasculature in primary gliomas triggered an increase in total tumor cell death. Despite the observed increase in cell killing, in mice with autochthonous DIPGs treated with radiation therapy, deletion of Atm specifically in tumor endothelial cells failed to improve survival. CONCLUSIONS: These results suggest that targeting the tumor cells, rather than endothelial cells, during radiation therapy will be necessary to improve survival among children with DIPG.

Tumor genotype dictates radiosensitization after Atm deletion in primary brainstem glioma models.

Diffuse intrinsic pontine glioma (DIPG) kills more children than any other type of brain tumor. Despite clinical trials testing many chemotherapeutic agents, palliative radiotherapy remains the standard treatment. Here, we utilized Cre/loxP technology to show that deleting Ataxia telangiectasia mutated (Atm) in primary mouse models of DIPG can enhance tumor radiosensitivity. Genetic deletion of Atm improved survival of mice with p53-deficient but not p53 wild-type gliomas after radiotherapy. Similar to patients with DIPG, mice with p53 wild-type tumors had improved survival after radiotherapy independent of Atm deletion. Primary p53 wild-type tumor cell lines induced proapoptotic genes after radiation and repressed the NRF2 target, NAD(P)H quinone dehydrogenase 1 (Nqo1). Tumors lacking p53 and Ink4a/Arf expressed the highest level of Nqo1 and were most resistant to radiation, but deletion of Atm enhanced the radiation response. These results suggest that tumor genotype may determine whether inhibition of ATM during radiotherapy will be an effective clinical approach to treat DIPGs.

Fatal case of vulvar pyoderma gangrenosum with pulmonary involvement: case presentation and literature review.

INTRODUCTION: We report a case of a 61-year-old woman with locally destructive vulvar pyoderma gangrenosum (PG) with pulmonary involvement who was refractory to numerous systemic therapies and developed complications resulting in her demise. OBJECTIVE: To report a rare case of treatment-resistant vulvar PG with pulmonary involvement that proved to be fatal. METHODS: PubMed was used to search for other reports that discuss PG, or more specifically perigenital PG, with pulmonary involvement. RESULTS AND CONCLUSION: A thorough review of the literature revealed 33 cases of PG with pulmonary involvement, with only 4 involving the perigenital region. We report the second case of a female with vulvar PG and pulmonary involvement. In contrast to the first case described, our patient did not respond to systemic therapy, and, ultimately, her disease was fatal. It is hoped that with continued documentation of this rare and potentially lethal presentation of PG, physicians will determine more effective treatments.

Familial pityriasis rubra pilaris: case report and review.

BACKGROUND: Pityriasis rubra pilaris (PRP) is a rare dermatosis of unknown etiology. Most cases of PRP are sporadic; however, rare cases of familial PRP have been reported. OBJECTIVES: To present a case of PRP inherited in an autosomal dominant (AD) fashion and to evaluate the current literature on familial PRP and formulate a comprehensive, up-to-date summary of this rare condition. METHODS: PubMed was used to conduct a search for articles pertaining to familial PRP published through May 2011. RESULTS: The first documented case was published in 1910, and 36 subsequent familial cases of PRP have been reported. Familial PRP typically presents very early in childhood, has a gradual onset, and persists throughout life. Given the rarity of this subtype, determining the best therapy has been a challenge. In the pediatric population, a conservative treatment approach, including topical therapy, is frequently used, whereas systemic treatments are reserved for patients with a severe disease that is refractory to therapy. CONCLUSION: Rare cases of PRP inherited in an AD fashion have been described and tend to have a chronic clinical course and are treatment refractory. Therefore, the awareness of familial PRP is important for early and accurate diagnosis and administration of appropriate therapy.