A review of pulmonary neutrophilia and insights into the key role of neutrophils in particle-induced pathogenesis in the lung from animal studies of lunar dusts and other poorly soluble dust particles.

The mechanisms of particle-induced pathogenesis in the lung remain poorly understood. Neutrophilic inflammation and oxidative stress in the lung are hallmarks of toxicity. Some investigators have postulated that oxidative stress from particle surface reactive oxygen species (psROS) on the dust produces the toxicopathology in the lungs of dust-exposed animals. This postulate was tested concurrently with the studies to elucidate the toxicity of lunar dust (LD), which is believed to contain psROS due to high-speed micrometeoroid bombardment that fractured and pulverized lunar surface regolith. Results from studies of rats intratracheally instilled (ITI) with three LDs (prepared from an Apollo-14 lunar regolith), which differed 14-fold in levels of psROS, and two toxicity reference dusts (TiO2 and quartz) indicated that psROS had no significant contribution to the dusts' toxicity in the lung. Reported here are results of further investigations by the LD toxicity study team on the toxicological role of oxidants in alveolar neutrophils that were harvested from rats in the 5-dust ITI study and from rats that were exposed to airborne LD for 4 weeks. The oxidants per neutrophils and all neutrophils increased with dose, exposure time and dust's cytotoxicity. The results suggest that alveolar neutrophils play a critical role in particle-induced injury and toxicity in the lung of dust-exposed animals. Based on these results, we propose an adverse outcome pathway (AOP) for particle-associated lung disease that centers on the crucial role of alveolar neutrophil-derived oxidant species. A critical review of the toxicology literature on particle exposure and lung disease further supports a neutrophil-centric mechanism in the pathogenesis of lung disease and may explain previously reported animal species differences in responses to poorly soluble particles. Key findings from the toxicology literature indicate that (1) after exposures to the same dust at the same amount, rats have more alveolar neutrophils than hamsters; hamsters clear more particles from their lungs, consequently contributing to fewer neutrophils and less severe lung lesions; (2) rats exposed to nano-sized TiO2 have more neutrophils and more severe lesions in their lungs than rats exposed to the same mass-concentration of micron-sized TiO2; nano-sized dust has a greater number of particles and a larger total particle-cell contact surface area than the same mass of micron-sized dust, which triggers more alveolar epithelial cells (AECs) to synthesize and release more cytokines that recruit a greater number of neutrophils leading to more severe lesions. Thus, we postulate that, during chronic dust exposure, particle-inflicted AECs persistently release cytokines, which recruit neutrophils and activate them to produce oxidants resulting in a prolonged continuous source of endogenous oxidative stress that leads to lung toxicity. This neutrophil-driven lung pathogenesis explains why dust exposure induces more severe lesions in rats than hamsters; why, on a mass-dose basis, nano-sized dusts are more toxic than the micron-sized dusts; why lung lesions progress with time; and why dose-response curves of particle toxicity exhibit a hockey stick like shape with a threshold. The neutrophil centric AOP for particle-induced lung disease has implications for risk assessment of human exposures to dust particles and environmental particulate matter.

Persistent changes in expression of genes involved in inflammation and fibrosis in the lungs of rats exposed to airborne lunar dust.

NASA is currently planning return missions to the Moon for further exploration and research. The Moon is covered by a layer of potentially reactive fine dust, which could pose a toxicological risk of exposure to explorers. To assess this risk, we exposed rats to lunar dust (LD) that was collected during the Apollo14 mission. Rats were exposed to respirable sizes of LD at concentrations of 0, 2.1, 6.8, 20.8, or 60.6 mg/m3 for 4 weeks. At thirteen weeks after exposure, we assessed 44,000 gene transcripts and found the expression of 614 genes with known functions were significantly altered in the rats exposed to the 2 higher concentrations of LD, whereas few changes in gene expression were detected in the group exposed to the lowest concentration of LD. Many of the significant changes in gene expression involved genes known to be associated with inflammation or fibrosis. Four genes encoding pro-inflammatory chemokines were analyzed further for all the sampling points at 1 day, and 1, 4, and 13 weeks after the 4-week dust exposure, using real-time polymerase chain reaction. The expression of these genes was altered in a dose- and time-dependent manner and persistently changed in the lungs of the rats exposed to the two higher concentrations of LD. Their expressions are consistent with changes we detected in pulmonary toxicity biomarkers and pathology in these animals during a previous study. Because Apollo-14 LD contains common mineral oxides similar to an Arizona volcanic ash, besides revealing the toxicity of LD, our findings could help elucidate the genomic and molecular mechanisms involved in pulmonary toxicity induced by terrestrial mineral dusts.

'The word that comes to mind is polymath': medical students' perceptions of rural postgraduate careers.

INTRODUCTION: Medical education is essential in strengthening the rural medical workforce globally. Immersive medical education in rural communities guided by good role models and rural-specific curricula promotes rural recruitment of recent graduates. While curricula can be rurally oriented, the mechanism of action is unclear. Comparing different programmes, this study examined medical students' perceptions of rural and remote practice and how these perceptions influence students' intentions to practice rurally. METHODS: The University of St Andrews has two medical programmes: BSc Medicine and graduate-entry MBChB (ScotGEM). Commissioned to address Scotland's rural generalist crisis, ScotGEM employs high quality role modelling, alongside 40-week immersive rural longitudinal integrated clerkships. This cross-sectional study utilised semi-structured interviews with 10 St Andrews students enrolled in undergraduate or graduate-entry medical programmes. We deductively applied Feldman and Ng's 'Careers: Embeddedness, Mobility, and Success' theoretical framework to examine rural medicine perceptions in medical students exposed to different programmes. RESULTS: Structural themes included geographically isolated physicians and patients. Organisational themes included limited staff support in rural practices and perceived inequitable resource allocation between rural and urban communities. Occupational themes included the recognition of rural clinical generalists. Personal themes included the perception of tight-knit rural communities. Medical students' experiences (educational, personal, or working) most profoundly shaped their perceptions. DISCUSSION: Medical students' perceptions align with professionals' reasons for career embeddedness. Perceptions unique to rurally interested medical students included isolation, the need for rural clinical generalists, uncertainty in rural medicine, and tight-knit rural communities. Educational experience mechanisms, including exposure to telemedicine, GP role-modelling, methods on overcoming uncertainty, and codesigned medical education programmes, explain perceptions.

Enhancing early career professionals' representation and engagement at international conferences: WONCA "Rural Early Career Ambassador Integration" project.

INTRODUCTION: International conferences offer an excellent opportunity for career development and are global academic opportunities with the potential to foster educational and professional growth. However, equitable access to participation and meaningful involvement in such events remains an issue. In this article we describe the novel Rural Early Career Ambassador Integration project and its implications for the 2022 World Rural Health Conference, held at the University of Limerick, Ireland. METHODS: The project offered vertical and cross-country collaborative opportunities to early career professionals with a passion for rural medicine. Three ambassadors of diverse nationalities, ethnicities and professional backgrounds were selected. They bore no personal cost for travel, transport or accommodation relating to the conference. Each ambassador was matched to and clinically shadowed an expert rural GP for a week preceding the conference, who provided mentorship. Mentors and ambassadors collaborated on goal-setting and work-planning throughout the conference, and were offered one-on-one career and networking support. The ambassadors were welcomed and integrated within a larger working party, the WONCA Working Party for Rural Health. RESULTS: The project was well received by conference delegates and organisers, and achieved its stated goal of enhancing conference equity through the representation and meaningful involvement of diverse early career professionals. Vertical and cross-country collaboration generated actionable policy implications as is evidenced by the ambassadors' co-authorship on the Limerick Declaration on Rural Healthcare. CONCLUSION: Although sponsorship for these initiatives remains a challenge, this project highlights the importance of actively including early career professionals at international conferences.

The Limerick Declaration on Rural Health Care 2022.

The 19th World Rural Health Conference, hosted in rural Ireland and the University of Limerick, with over 650 participants coming from 40 countries and an additional 1600 engaging online, has carefully considered how best rural communities can be empowered to improve their own health and the health of those around them. The conference also considered the role of national health systems and all stakeholders, in keeping with the commitments made through the Sustainable Development Goals and the enjoyment of the highest attainable standard of health as one of the fundamental rights of every human being. This conference declaration, the Limerick Declaration on Rural Healthcare, is designed to inform rural communities, academics and policymakers about how to achieve the goal of delivering high quality health care in rural and remote areas most effectively, with a particular focus on the Irish healthcare system. Congruent with current evidence and best international practice, the participants of the conference endorsed a series of recommendations for the creation of high quality, sustainable and cost-effective healthcare delivery for rural communities in Ireland and globally. The recommendations focused on four major themes: rural healthcare needs and delivery, rural workforce, advocacy and policy, and research for rural health care. Equal access to health care is a crucial marker of democracy. Hence, we call on all governments, policymakers, academic institutions and communities globally to commit to providing their rural dwellers with equitable access to health care that is properly resourced and fundamentally patient-centred in its design.

Comparative pulmonary toxicities of lunar dusts and terrestrial dusts (TiO2 & SiO2) in rats and an assessment of the impact of particle-generated oxidants on the dusts' toxicities.

Humans will set foot on the Moon again soon. The lunar dust (LD) is potentially reactive and could pose an inhalation hazard to lunar explorers. We elucidated LD toxicity and investigated the toxicological impact of particle surface reactivity (SR) using three LDs, quartz, and TiO2. We first isolated the respirable-size-fraction of an Apollo-14 regolith and ground two coarser samples to produce fine LDs with increased SR. SR measurements of these five respirable-sized dusts, determined by their in-vitro ability to generate hydroxyl radicals (•OH), showed that ground LDs > unground LD ≥ TiO2 ≥ quartz. Rats were each intratracheally instilled with 0, 1, 2.5, or 7.5 mg of a test dust. Toxicity biomarkers and histopathology were assessed up to 13 weeks after the bolus instillation. All dusts caused dose-dependent-increases in pulmonary lesions and toxicity biomarkers. The three LDs, which possessed mineral compositions/properties similar to Arizona volcanic ash, were moderately toxic. Despite a 14-fold •OH difference among these three LDs, their toxicities were indistinguishable. Quartz produced the lowest •OH amount but showed the greatest toxicity. Our results showed no correlation between the toxicity of mineral dusts and their ability to generate free radicals. We also showed that the amounts of oxidants per neutrophil increased with doses, time and the cytotoxicity of the dusts in the lung, which supports our postulation that dust-elicited neutrophilia is the major persistent source of oxidative stress. These results and the discussion of the crucial roles of the short-lived, continuously replenished neutrophils in dust-induced pathogenesis are presented.

'The word that comes to mind is polymath': medical students' perceptions of rural postgraduate careers.

INTRODUCTION: Physician shortages in rural and remote areas challenge accessibility and delivery of care to rural and remote communities, including within Scotland. Medical education is a reform priority to establish a sustainable medical workforce. Although there is evidence to support aspects of medical education that enhance the likelihood of practising rurally, the mechanism by which these educational initiatives work is not clearly understood. This study aimed to examine medical students' perceptions of rural and remote practice, how these perceptions motivate their interest to practise rurally, and what aspects of education are thought to influence these perceptions. METHODS: This cross-sectional study utilised semistructured interviews with 10 University of St Andrews medical students enrolled in undergraduate or graduate-entry medical education programs. Feldman and Ng's theoretical framework was deductively applied. Interviews informed additional subthemes, which were integrated into the original framework. The final framework helped examine medical students' perceptions of rural medicine and mechanisms that shape these perceptions. RESULTS: Structural (countrywide) themes included geographical barriers affecting patients and physicians. Organisational themes included perceptions of inequitable allocation of resources between urban and rural areas, as well as limited staff and support in rural practices. Occupational themes included the perception of rural clinical generalists. Personal life themes included the perception of community in rural areas. Mechanisms shaping medical students' perceptions most profoundly were their experiences (educational, personal experience or working). CONCLUSION: Medical students' perceptions align with other professionals' reasons for staying in a particular job. Perceptions regarding rural careers included challenges due to geographical proximity to patients, resource allocation in rural areas, and the potential to subspecialise as a general rural practitioner. Identified mechanisms, which shape perceptions, can be addressed and strengthened by educators, policy-makers and governments to optimise medical education that promotes rural recruitment and retention.

Estimating safe human exposure levels for lunar dust using benchmark dose modeling of data from inhalation studies in rats.

The pulmonary toxicity of airborne lunar dust was assessed in rats exposed by nose-only inhalation to 0, 2.1, 6.8, 20.8 and 60.6 mg/m3 of respirable size lunar dust. Rats were exposed for 6 h/d, 5 d/week, for 4 weeks (120 h). Biomarkers of toxicity were assessed in bronchial alveolar lavage fluid (BALF) collected at 1 d, 1 week, 4 weeks or 13 weeks post-exposure for a total of 76 endpoints. Benchmark dose (BMD) analysis was conducted on endpoints that appeared to be sensitive to dose. The number of endpoints that met criteria for modeling was 30. This number was composed of 13 endpoints that produced data suitable for parametric analysis and 17 that produced non-normal data. Mean BMD values determined from models generated from non-normal data were lower but not significantly different from the mean BMD of models derived from normally distributed data. Thus BMDs ranged from a minimum of 10.4 (using the average BMD from all 30 modeled endpoints) to a maximum of 16.6 (using the average BMD from the most restricted set of models). This range of BMDs yields safe exposure estimate (SEE) values of 0.6 and 0.9 mg/m3, respectively, when BMDs are extrapolated to humans, using a species factor of 3 and extrapolated from a 1-month exposure to an anticipated 6-month lunar surface exposure. This estimate is very similar to a no-observable-adverse-effect-level (NOAEL) determined from the same studies (0.4 mg/m3) and a SEE derived from a study of rats that were intratracheally instilled with lunar dusts (0.5-1.0 mg/m3).

Estimate of safe human exposure levels for lunar dust based on comparative benchmark dose modeling.

Brief exposures of Apollo astronauts to lunar dust occasionally elicited upper respiratory irritation; however, no limits were ever set for prolonged exposure to lunar dust. The United States and other space faring nations intend to return to the moon for extensive exploration within a few decades. In the meantime, habitats for that exploration, whether mobile or fixed, must be designed to limit human exposure to lunar dust to safe levels. Herein we estimate safe exposure limits for lunar dust collected during the Apollo 14 mission. We instilled three respirable-sized (∼2 µ mass median diameter) lunar dusts (two ground and one unground) and two standard dusts of widely different toxicities (quartz and TiO2) into the respiratory system of rats. Rats in groups of six were given 0, 1, 2.5 or 7.5 mg of the test dust in a saline-Survanta® vehicle, and biochemical and cellular biomarkers of toxicity in lung lavage fluid were assayed 1 week and one month after instillation. By comparing the dose--response curves of sensitive biomarkers, we estimated safe exposure levels for astronauts and concluded that unground lunar dust and dust ground by two different methods were not toxicologically distinguishable. The safe exposure estimates were 1.3 ± 0.4 mg/m³ (jet-milled dust), 1.0 ± 0.5 mg/m³ (ball-milled dust) and 0.9 ± 0.3 mg/m³ (unground, natural dust). We estimate that 0.5-1 mg/m³ of lunar dust is safe for periodic human exposures during long stays in habitats on the lunar surface.

Toxicity of lunar dust assessed in inhalation-exposed rats.

Humans will again set foot on the moon. The moon is covered by a layer of fine dust, which can pose a respiratory hazard. We investigated the pulmonary toxicity of lunar dust in rats exposed to 0, 2.1, 6.8, 20.8 and 60.6 mg/m(3) of respirable-size lunar dust for 4 weeks (6 h/day, 5 days/week); the aerosols in the nose-only exposure chambers were generated from a jet-mill ground preparation of a lunar soil collected during the Apollo 14 mission. After 4 weeks of exposure to air or lunar dust, groups of five rats were euthanized 1 day, 1 week, 4 weeks or 13 weeks after the last exposure for assessment of pulmonary toxicity. Biomarkers of toxicity assessed in bronchoalveolar fluids showed concentration-dependent changes; biomarkers that showed treatment effects were total cell and neutrophil counts, total protein concentrations and cellular enzymes (lactate dehydrogenase, glutamyl transferase and aspartate transaminase). No statistically significant differences in these biomarkers were detected between rats exposed to air and those exposed to the two low concentrations of lunar dust. Dose-dependent histopathology, including inflammation, septal thickening, fibrosis and granulomas, in the lung was observed at the two higher exposure concentrations. No lesions were detected in rats exposed to ≤6.8 mg/m(3). This 4-week exposure study in rats showed that 6.8 mg/m(3) was the highest no-observable-adverse-effect level (NOAEL). These results will be useful for assessing the health risk to humans of exposure to lunar dust, establishing human exposure limits and guiding the design of dust mitigation systems in lunar landers or habitats.

The impact of value-based benefit design on adherence to diabetes medications: a propensity score-weighted difference in difference evaluation.

OBJECTIVE: To evaluate the impact of value-based benefit design (VBBD) on adherence to diabetes medications. METHODS: Health Alliance Medical Plans piloted VBBD for diabetes medications for a subgroup of 5400 enrollees in January 2007 while keeping drug benefits unchanged for the remaining plan enrollees. A difference in difference method (DID) was used to evaluate the effect of VBBD based on pharmacy claim data. Patients with unchanged benefits in the same plan were used as the control group. Adherence was measured by the proportion of days covered. Propensity score weighting was used to balance characteristics of the case group and the control group. RESULTS: There were 71 patients in the case group and 5037 patients in the control group. The patients in the two groups had comparable characteristics after propensity score weighting. After the implementation of VBBD, the average copayment per 30 days of supply for diabetes medications decreased from $15.3 to $10.1 for the case group and increased from $14.6 to $15.1 for the control group. The probability of being adherent increased from 75.3% to 82.6% for the case group and was roughly unchanged from 79.1% to 78.5% for the control group. Propensity score-weighted DID analysis showed that patients with copayment reduction had greater odds of being adherent: odds ratio=1.56, P=0.03, 95% confidence interval 1.04-2.34. CONCLUSION: A VBBD program that reduced the copayment for diabetes medications by 36.1% reduced the number of nonadherent patients by 30.0%.

Informed consent, shared-decision making and a reasonable patient's wishes based on a cross-sectional, national survey in the USA using a hypothetical scenario.

OBJECTIVE: In approximately half the states in the USA, and more recently in the UK, informed consent is legally defined as what a reasonable patient would wish to know. Our objective was to discern the information needs of a hospitalised, 'reasonable patient' during the informed-consent process. DESIGN: We performed a cross-sectional study to develop a survey instrument and better define 'reasonable person' in relation to informed consent in a hypothetical scenario where an invasive procedure may be an option. SETTING: A 10-question survey was administered from April 19 through 22 October 2018 to three groups: student nurses (n=76), health professions educators (n=63) and a US national population (n=1067). PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome measure was the average intensity, on a 5-point scale, by which survey groups wished to have each of 10 questions answered. The secondary outcome was to discern relationships between survey demographics and the intensity by which participants wanted an answer. RESULTS: Despite substantial demographic differences in the nursing-student group and health-professions-educator group, the average intensity scores were within 0.2 units on nine of 10 questions. The national survey revealed a strong desire to have an answer to each question (range 3.98-4.60 units). It showed that women desired answers more than men and older adults desired answers more than younger adults. CONCLUSIONS: Based on responses to 10 survey questions regarding wishes of people in a situation where an invasive procedure may be necessary, the vast majority want an answer to each question. They wanted to know about all treatment options, risky drugs, decision aids, who will perform the procedure, and the cost. They wanted their advocate present, periodic review of their medical record, a full day to review documents and expected outcomes and restrictions after the procedure.

Near-Unity Light Collection Efficiency from Quantum Emitters in Boron Nitride by Coupling to Metallo-Dielectric Antennas.

The bright and stable single-photon emission under room temperature conditions from color centers in hexagonal boron nitride (hBN) is considered as one of the most promising quantum light sources for quantum cryptography as well as spin-based qubits, similar to recent advances in nitrogen-vacancy centers in diamond. To this end, integration with cavity or waveguide modes is required to enable ideally lossless transduction of quantum light states. Here, we demonstrate a scheme to embed hBN quantum emitters into on-chip arrays of metallo-dielectric antennas that provides near unity light collection efficiencies with experimental values up to 98%, i.e. a 7-fold enhancement compared to bare quantum emitters. Room-temperature quantum light emission in the 700 nm band is characterized with single-photon emission rates into the first lens up to 44 MHz under continuous excitation and up to 10 MHz under 80 MHz pulsed excitation (0.13 photons per trigger pulse) into a narrow output cone (±15°) that facilitates fiber butt-coupling. We furthermore provide here a direct measurement of the quantum yield under pulsed excitation with values of 6-12% for hBN nanoflakes. Our demonstrated scheme could enable low loss spin-photon interfaces on a chip.

Revisions to Limits for Methanol in the Air of Spacecraft.

INTRODUCTION: The previous Spacecraft Maximal Allowable Concentrations (SMACs) for methanol were established by characterizing minor effects upon cognitive functions as a no-observable adverse effects level (NOAEL). However, an increasing awareness of the risk posed by Space-Associated Neuro-ocular Syndrome (SANS) has caused NASA Toxicology to reexamine SMACs for methanol because exposure to it can also adversely affect ocular health. An updated review of the literature indicates that no adjustments to the SMACs due to SANS complications were required, while confirming that effects upon the central nervous system remain the appropriate basis for the SMACs for methanol. Our review, however, identified several issues that provide justification for modest SMAC reductions. It has recently been recognized that inhaled methanol may reach the brain via the olfactory system and be absorbed there into the highly toxic metabolite formaldehyde. A benchmark dose (BMD) for an extra risk of 10%, derived from an analysis of the incidences of neurological lesions in monkeys chronically exposed to methanol, is an order of magnitude less than the Environmental Protection Agency's (EPA's) reference concentration for chronic inhalation of methanol. Reports calling attention to the relative insensitivity of traditional methods of assessing cognitive function erode confidence that adverse effects at the concentration reported as a NOAEL would have been recognizable. Therefore, an additional modest safety factor of three is applied to SMACs for methanol.Scully RR, Garcia H, McCoy JT, Ryder VE. Revisions to limits for methanol in the air of spacecraft. Aerosp Med Hum Perform. 2019; 90(9):807-812.

Effects of acute exposures to carbon dioxide on decision making and cognition in astronaut-like subjects.

Acute exposure to carbon dioxide (CO2) concentrations below those found on the International Space Station are reported to deteriorate complex decision-making. Effective decision-making is critical to human spaceflight, especially during an emergency response. Therefore, effects of acutely elevated CO2 on decision-making competency and various cognitive domains were assessed in astronaut-like subjects by the Strategic Management Simulation (SMS) and Cognition test batteries. The double-blind cross-over study included 22 participants at the Johnson Space Center randomly assigned to one of four groups. Each group was exposed to a different sequence of four concentrations of CO2 (600, 1200, 2500, 5000 ppm). Subjects performed Cognition before entering the chamber, 15 min and 2.5 h after entering the chamber, and 15 min after exiting the chamber. The SMS was administered 30 min after subjects entered the chamber. There were no clear dose-response patterns for performance on either SMS or Cognition. Performance on most SMS measures and aggregate speed, accuracy, and efficiency scores across Cognition tests were lower at 1200 ppm than at baseline (600 ppm); however, at higher CO2 concentrations performance was similar to or exceeded baseline for most measures. These outcomes, which conflict with those of other studies, likely indicate differing characteristics of the various subject populations and differences in the aggregation of unrecognized stressors, in addition to CO2, are responsible for disparate outcomes among studies. Studies with longer exposure durations are needed to verify that cognitive impairment does not develop over time in crew-like subjects.

Predicting Air Quality at First Ingress into Vehicles Visiting the International Space Station.

INTRODUCTION: NASA regularly performs ground-based offgas tests (OGTs), which allow prediction of accumulated volatile pollutant concentrations at first entry on orbit, on whole modules and vehicles scheduled to connect to the International Space Station (ISS). These data guide crew safety operations and allow for estimation of ISS air revitalization systems impact from additional pollutant load. Since volatiles released from vehicle, module, and payload materials can affect crew health and performance, prediction of first ingress air quality is important. METHODS: To assess whether toxicological risk is typically over or underpredicted, OGT and first ingress samples from 10 vehicles and modules were compared. Samples were analyzed by gas chromatography and gas chromatography-mass spectrometry. The rate of pollutant accumulation was extrapolated over time. Ratios of analytical values and Spacecraft Maximum Allowable Concentrations were used to predict total toxicity values (T-values) at first entry. Results were also compared by compound. RESULTS: Frequently overpredicted was 2-butanone (9/10), whereas propanal (6/10) and ethanol (8/10) were typically underpredicted, but T-values were not substantially affected. Ingress sample collection delay (estimated by octafluoropropane introduced from ISS atmosphere) and T-value prediction accuracy correlated well (R2 = 0.9008), highlighting the importance of immediate air sample collection and accounting for ISS air dilution. DISCUSSION: Importantly, T-value predictions were conservative 70% of the time. Results also suggest that T-values can be normalized to octafluoropropane levels to adjust for ISS air dilution at first ingress. Finally, OGT and ingress sampling has allowed small leaks in vehicle fluid systems to be recognized and addressed.Romoser AA, Scully RR, Limero TF, De Vera V, Cheng PF, Hand JJ, James JT, Ryder VE. Predicting air quality at first ingress into vehicles visiting the International Space Station. Aerosp Med Hum Perform. 2017; 88(2):104-113.

Krukenberg tumors of the ovary: a clinicopathologic analysis of 120 cases with emphasis on their variable pathologic manifestations.

120 Krukenberg tumors were analyzed with emphasis on their wide microscopic spectrum and resultant problems in differential diagnosis. The patients ranged from 13 to 84 years (average, 45 years) with 43% of them under 40 years. Abdominal swelling or pain usually accounted for the clinical presentation, but 17 had abnormal vaginal bleeding, 4 had virilization, and 4 had hirsutism without virilization. Ascites was present in 43% of the cases. Sixty-three percent of the tumors were documented to be bilateral, but both ovaries were not always removed or rigorously examined microscopically. The mean diameter of the tumors was 10.4 cm, and they typically had intact, bosselated external surfaces without adhesions. The sectioned surfaces were typically solid and firm to edematous to gelatinous; one third of the tumors also had cysts. Microscopic examination showed great variation from case to case and within individual neoplasms. Multiple nodules separated by normal stroma were seen in small neoplasms and focally in many larger ones. The tumors were often more cellular at their periphery and edematous to gelatinous centrally. An irregular distribution of cellular and less cellular areas often imparted a pseudolobular pattern. The cellularity of the stroma ranged from densely cellular to paucicellular; the latter regions ranged from edematous to mucoid. The overall morphology varied according to the prominence of signet-ring cells, extracellular mucin, edema, and various epithelial patterns. Signet-ring cells were numerous in most neoplasms (and by definition occupied at least 10% of the neoplasm) but were often absent or inconspicuous in significant areas of them. The signet-ring cells typically had modest but sometimes copious amounts of pale to basophilic cytoplasm; occasionally, it was eosinophilic. The signet-ring cells varied widely in their arrangement, growing singly, in clusters, forming confluent masses or pseudo-tubular arrays or lining part of all of a true tubule. Small glands and tubules were common, often resembling microcysts (when the lining cells were flattened) or Sertoli tubules; mucinous glands and cysts and medium-sized to large intestinal-type glands were also relatively common, particularly the latter. Extracellular mucin was often conspicuous and, when associated with scant acellular collagenous stroma, gave a distinctive appearance referred to by us as "feathery degeneration." Stromal luteinization was present in the tumors of the 8 pregnant patients and was seen in 14% of the nonpregnant patients. Unusual features that complicated the microscopic picture included diffuse sheets or other arrangements of mucin-free indifferent cells, squamous cells, clear cells, transitional cells, and corded, trabecular, and insular patterns. Vascular space invasion was common. Two thirds of the primary carcinomas were detected synchronously with, or subsequent to, detection of the Krukenberg tumor compounding the diagnostic difficulty posed by the cases. Two thirds of the primary tumors were in the stomach; other primary sites in order of frequency were appendix, colon, breast, small intestine, rectum, gallbladder, and urinary bladder. Our observations emphasize that the microscopic spectrum of the Krukenberg tumor is broader that often presented in the literature, in particular tubules, glands, and cysts often being present, and the wide pathologic differential diagnosis is discussed.

Mesodermal (müllerian) adenosarcoma of the ovary: a clinicopathologic analysis of 40 cases and a review of the literature.

Forty cases of mesodermal adenosarcoma of the ovary occurred in women 30-84 years of age (mean 54 years). Abdominal discomfort and distension were the usual complaints. All the patients were treated with an oophorectomy, which was accompanied by a hysterectomy in 85%, a contralateral oophorectomy in 65%, and nonsurgical therapy in 28%. Tumor rupture occurred at or before the operation in 67% of the cases. Twenty-six tumors were stage I, 11 stage II, and 3 stage III. The tumors were unilateral in 97.5% of the cases and 5.5-50 cm (mean 14 cm) in greatest dimension; most of the tumors were predominantly solid but contained numerous small cysts. Microscopic examination revealed sarcomatous overgrowth in 12 tumors. Sex cord-like elements were present in six tumors (including four with sarcomatous overgrowth) and heterologous elements in five (including two with sarcomatous overgrowth). The highest mitotic index of the sarcomatous component was 1-25 (mean 6) mitotic figures per 10 high power fields. Only 6 of 26 women (23%) who were followed postoperatively for > or=5 years were free of tumor. In the other 20 patients recurrent tumor appeared at 0.4-6.6 years (mean 2.6 years) after operation as pure sarcoma (low grade or high grade) or adenosarcoma (with or without sarcomatous overgrowth). Eight women had additional recurrences, and four women had blood-borne metastases. One patient was alive at 15.7 years after the excision of pulmonary metastases. The 5-, 10-, and 15-year survival rates were 64%, 46%, and 30%, respectively. Age <53 years, tumor rupture, a high grade, and the presence of high-grade sarcomatous overgrowth appeared to be associated with recurrence or extraovarian spread. Ovarian adenosarcomas have a worse prognosis than uterine adenosarcomas, presumably because of the greater ease of peritoneal spread. Many of the tumors caused problems in differential diagnosis.