Depression Is Associated With Non-Home Discharge After Coronary Artery Bypass Graft.

INTRODUCTION: Depression is disproportionately high in patients with coronary artery disease and has been associated with adverse outcomes following coronary artery bypass graft (CABG). One quality metric, non-home discharge (NHD), can have substantial implications for patients and health care resource utilization. Depression increases the risk of NHD after many operations, but it has not been studied after CABG. We hypothesized that a history of depression would be associated with an increased risk of NHD following CABG. METHODS: CABG cases were identified from the 2018 National Inpatient Sample using ICD-10 codes. Depression, demographic data, comorbidities, length of stay (LOS), rate of NHD were analyzed using appropriate statistical tests where a P-value < 0.05 was defined as statistically significant. Adjusted multivariable logistic regression models were used to assess independent association between depression and NHD as well as LOS while controlling for confounders. RESULTS: There were 31,309 patients, of which 2743 (8.8%) had depression. Depressed patients were younger, females, in a lower income quartile, and more medically complex. They also demonstrated more frequent NHD and prolonged LOS. After adjusted multivariable analysis, depressed patients had a 70% increased odds of NHD (adjusted odds ratio: 1.70 [1.52-1.89] P < 0.001) and a 24% increased odds of prolonged LOS (AOR: 1.24 [1.12-1.38] P < 0.001). CONCLUSIONS: From a national sample, depressed patients were associated with more frequent NHD following CABG. To our knowledge, this is the first study to demonstrate this, and it highlights the need for improved preoperative identification in order to improve risk stratification and timely allocation of discharge services.

Chemical Characterization and Determination of the Antioxidant Properties of Phenolic Compounds in Three Scutellaria sp. Plants Grown in Colombia.

Plants of the genus Scutellaria (Lamiaceae) have a wide variety of bioactive secondary metabolites with diverse biological properties, e.g., anti-inflammatory, antiallergenic, antioxidant, antiviral, and antitumor activities. The chemical composition of the hydroethanolic extracts, obtained from dried plants of S. incarnata, S. coccinea, and S. ventenatii × S. incarnata, was determined by UHPLC/ESI-Q-Orbitrap-MS. The flavones were found in a higher proportion. Baicalin and dihydrobaicalein-glucuronide were the major extract components in S. incarnata (287.127 ± 0.005 mg/g and 140.18 ± 0.07 mg/g), in S. coccinea (158.3 ± 0.34 mg/g and 51.20 ± 0.02 mg/g), and in S. ventenatii × S. incarnata (186.87 ± 0.01 mg/g and 44.89 ± 0.06 mg/g). The S. coccinea extract showed the highest antioxidant activity in the four complementary techniques employed to evaluate all extracts: ORAC (3828 ± 3.0 µmol Trolox®/g extract), ABTS+• (747 ± 1.8 µmol Trolox®/g extract), online HPLC-ABTS+• (910 ± 1.3 µmol Trolox®/g extract), and ß-carotene (74.3 ± 0.8 µmol Trolox®/g extract).

Neurobiological and behavioral mechanisms of circadian rhythm disruption in bipolar disorder: A critical multi-disciplinary literature review and agenda for future research from the ISBD task force on chronobiology.

AIM: Symptoms of bipolar disorder (BD) include changes in mood, activity, energy, sleep, and appetite. Since many of these processes are regulated by circadian function, circadian rhythm disturbance has been examined as a biological feature underlying BD. The International Society for Bipolar Disorders Chronobiology Task Force (CTF) was commissioned to review evidence for neurobiological and behavioral mechanisms pertinent to BD. METHOD: Drawing upon expertise in animal models, biomarkers, physiology, and behavior, CTF analyzed the relevant cross-disciplinary literature to precisely frame the discussion around circadian rhythm disruption in BD, highlight key findings, and for the first time integrate findings across levels of analysis to develop an internally consistent, coherent theoretical framework. RESULTS: Evidence from multiple sources implicates the circadian system in mood regulation, with corresponding associations with BD diagnoses and mood-related traits reported across genetic, cellular, physiological, and behavioral domains. However, circadian disruption does not appear to be specific to BD and is present across a variety of high-risk, prodromal, and syndromic psychiatric disorders. Substantial variability and ambiguity among the definitions, concepts and assumptions underlying the research have limited replication and the emergence of consensus findings. CONCLUSIONS: Future research in circadian rhythms and its role in BD is warranted. Well-powered studies that carefully define associations between BD-related and chronobiologically-related constructs, and integrate across levels of analysis will be most illuminating.

Measuring circadian function in bipolar disorders: Empirical and conceptual review of physiological, actigraphic, and self-report approaches.

BACKGROUND: Interest in biological clock pathways in bipolar disorders (BD) continues to grow, but there has yet to be an audit of circadian measurement tools for use in BD research and practice. PROCEDURE: The International Society for Bipolar Disorders Chronobiology Task Force conducted a critical integrative review of circadian methods that have real-world applicability. Consensus discussion led to the selection of three domains to review-melatonin assessment, actigraphy, and self-report. RESULTS: Measurement approaches used to quantify circadian function in BD are described in sufficient detail for researchers and clinicians to make pragmatic decisions about their use. A novel integration of the measurement literature is offered in the form of a provisional taxonomy distinguishing between circadian measures (the instruments and methods used to quantify circadian function, such as dim light melatonin onset) and circadian constructs (the biobehavioral processes to be measured, such as circadian phase). CONCLUSIONS: Circadian variables are an important target of measurement in clinical practice and biomarker research. To improve reproducibility and clinical application of circadian constructs, an informed systematic approach to measurement is required. We trust that this review will decrease ambiguity in the literature and support theory-based consideration of measurement options.

Cell fate analysis in fetal mouse lung reveals distinct pathways for TI and TII cell development.

Alveolar type I (TI) cells are large squamous cells that cover >95% of the internal surface area of the lung; type II (TII) cells are small cuboidal cells with distinctive intracellular surfactant storage organelles. Based on autoradiographic studies in the 1970s, the long-held paradigm of alveolar epithelial development has been a linear progression from undifferentiated progenitor cells through TII cells to TI cells. Subsequent data support the existence of more complex pathways. Recently, a bipotent TI/TII progenitor cell at embryonic day E18 has been inferred both from marker expression in developing airways and from statistical analyses of gene expression data obtained from single-lung embryonic cells. To study cell lineage directly by fate mapping, we developed new transgenic mouse models in which rtTA is driven either by the rat podoplanin or the mouse Sftpc gene to mark cells irreversibly in development. Using these models, we found two distinct lineage pathways. One pathway, evident as early as E12-15, is devoted almost exclusively to TI cell development; a second pathway gives rise predominantly to TII cells but also a subpopulation of TI cells. We have defined the molecular phenotypes of these distinct progenitor populations and have identified potential regulatory factors in TI and TII cell differentiation. By analyzing gene pathways in mature TI and TII cells, we identified potential novel functions of each cell type. These results provide novel insights into lung development and suggest a basis for testing strategies to promote alveolar differentiation and repair, including potential transplantation of lineage-specific progenitor cells.

Infant Mortality Rate as a Measure of a Country's Health: A Robust Method to Improve Reliability and Comparability.

Researchers and policymakers often rely on the infant mortality rate as an indicator of a country's health. Despite arguments about its relevance, uniform measurement of infant mortality is necessary to guarantee its use as a valid measure of population health. Using important socioeconomic indicators, we develop a novel method to adjust country-specific reported infant mortality figures. We conclude that an augmented measure of mortality that includes both infant and late fetal deaths should be considered when assessing levels of social welfare in a country. In addition, mortality statistics that exhibit a substantially high ratio of late fetal to early neonatal deaths should be more closely scrutinized.

High-efficiency type II cell-enhanced green fluorescent protein expression facilitates cellular identification, tracking, and isolation.

We have developed a transgenic mouse expressing enhanced green fluorescent protein (EGFP) in virtually all type II (TII) alveolar epithelial cells. The CBG mouse (SPC-BAC-EGFP) contains a bacterial artificial chromosome modified to express EGFP within the mouse surfactant protein (SP)-C gene 3' untranslated region. EGFP mRNA expression is limited to the lung. EGFP fluorescence is both limited to and exhibited by all cells expressing pro-SP-C; fluorescence is uniform throughout all lobes of the lung and does not change as mice age. EGFP(+) cells also express SP-B but do not express podoplanin, a type I (TI) cell marker. CBG mice show no evidence of lung disease with aging. In 3 hours, TII cells can be isolated in >99% purity from CBG mice by FACS; the yield of 3.7 ± 0.6 × 10(6) cells represents approximately 25 to 60% of the TII cells in the lung. By FACS analysis, approximately 0.9% of TII cells are in mitosis in uninjured lungs; after bleomycin injury, 4.1% are in mitosis. Because EGFP fluorescence can be detected for >14 days in culture, at a time that SP-C mRNA expression is essentially nil, this line may be useful for tracking TII cells in culture and in vivo. When CBG mice are crossed to transgenic mice expressing rat podoplanin, TI and TII cells can be easily simultaneously identified and isolated. When bred to other strains of mice, EGFP expression can be used to identify TII cells without the need for immunostaining for SP-C. These mice should be useful in models of mouse pulmonary disease and in studies of TII cell biology, biochemistry, and genetics.

Preventive Measures among Healthcare Workers (HCWs) during the COVID-19 Pandemic.

COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), placed health systems worldwide under immense pressure, and healthcare workers (HCWs) were at the front lines. The Puerto Rico Department of Health confirmed the first case of COVID-19 in March 2020. We aimed to assess whether COVID-19 preventive measures implemented by HCWs were effective in a work scenario before vaccine availability. We conducted a descriptive cross-sectional study from July to December 2020 to evaluate the use of personal protective equipment (PPE), hygiene guidelines, and other measures taken by HCWs to prevent the spread of SARS-CoV-2. We collected nasopharyngeal specimens for molecular testing at the beginning of the study and follow-up. We recruited 62 participants aged 30-59 (79% women). Participants recruited from hospitals, clinical laboratories, and private practice included medical technologists (33%), nurses (28%), respiratory therapists (2%), physicians (11%), and others (26%). Among our participants, nurses were at higher risk (p < 0.05) of infection. We identified that 87% of participants followed the hygiene recommendation guidelines. In addition, all participants practiced handwashing or disinfection before or after caring for each patient. All participants tested negative for SARS-CoV-2 during the study period. On follow-up, all study participants reported being vaccinated against COVID-19. The implementation of PPE and hygiene measures showed high efficacy as a prevention method against SARS-CoV-2 infection when vaccines and treatment were not widely available in Puerto Rico.

Distribution and surfactant association of carcinoembryonic cell adhesion molecule 6 in human lung.

Carcinoembryonic cell adhesion molecule 6 (CEACAM6) is a glycosylated, glycophosphatidylinositol-anchored protein expressed in epithelial cells of various primate tissues. It binds gram-negative bacteria and is overexpressed in human cancers. CEACAM6 is associated with lamellar bodies of cultured type II cells of human fetal lung and protects surfactant function in vitro. In this study, we characterized CEACAM6 expression in vivo in human lung. CEACAM6 was present in lung lavage of premature infants at birth and increased progressively in intubated infants with lung disease. Of surfactant-associated CEACAM6, ∼80% was the fully glycosylated, 90-kDa form that contains the glycophosphatidylinositol anchor, and the concentration (3.9% of phospholipid for adult lung) was comparable to that for surfactant proteins (SP)-A/B/C. We examined the affinity of CEACAM6 by purification of surfactant on density gradient centrifugation; concentrations of CEACAM6 and SP-B per phospholipid were unchanged, whereas levels of total protein and SP-A decreased by 60%. CEACAM6 mRNA content decreased progressively from upper trachea to peripheral fetal lung, whereas protein levels were similar in all regions of adult lung, suggesting proximal-to-distal developmental expression in lung epithelium. In adult lung, most type I cells and ∼50% of type II cells were immunopositive. We conclude that CEACAM6 is expressed by alveolar and airway epithelial cells of human lung and is secreted into lung-lining fluid, where fully glycosylated protein binds to surfactant. Production appears to be upregulated during neonatal lung disease, perhaps related to roles of CEACAM6 in surfactant function, cell proliferation, and innate immune defense.

Are socio-demographic and economic characteristics good predictors of misinformation during an epidemic?

We combine data on beliefs about the origin of the 2014 Ebola outbreak with two supervised machine learning methods to predict who is more likely to be misinformed. Contrary to popular beliefs, we uncover that, socio-demographic and economic indicators play a minor role in predicting those who are misinformed: misinformed individuals are not any poorer, older, less educated, more economically distressed, more rural, or ethnically different than individuals who are informed. However, they are more likely to report high levels of distrust, especially towards governmental institutions. By distinguishing between types of beliefs, distrust in the central government is the primary predictor of individuals assigning a political origin to the epidemic, while Muslim religion is the most important predictor of whether the individual assigns a supernatural origin. Instead, educational level has a markedly higher importance for ethnic beliefs. Taken together, the results highlight that government trust might play the most important role in reducing misinformation during epidemics.

Chronbiologically-based sub-groups in bipolar I disorder: A latent profile analysis.

BACKGROUND: Bipolar disorder presents with significant phenotypic heterogeneity. The aim of this study was to investigate whether bipolar disorder, type I (BDI) subjects could be meaningfully classified into homogeneous groups according to activity, sleep, and circadian characteristics using latent profile analysis (LPA). We hypothesized that distinct BDI sub-groups would be identified based primarily on circadian-associated markers. MATERIALS AND METHODS: 105 individuals with BDI were included in the study. Seventeen activity, sleep, and circadian characteristics were assessed via actigraphy and clinical assessments. LPA was conducted to stratify our sample into homogenous sub-groups. Differences between groups on demographic, clinical, activity, sleep, and circadian characteristics were explored. RESULTS: Two distinct groups were identified, a High Chronobiological Disturbance group (HCD) (56%, N = 59) and a Low Chronobiological Disturbance group (LCD) (41%; N = 46). Circadian variables were the defining characteristics in sub-group determination. Large effect sizes and magnitudes of association were noted in circadian variables between HCD and LCD sub-groups. Several circadian rhythm variables accounted for a large percentage of the variance between HCD and LCD sub-groups. No differences were noted between sub-groups on demographic characteristics and the psychiatric medications currently in use. Mood state did not significantly impact sub-group differences. LIMITATIONS: The protocol was cross-sectional in design. Longitudinal studies are required to determine the stability of the identified sub-groups. CONCLUSION: LPA was able to identify sub-groups in BDI with circadian variables being the most distinguishing factors in determining sub-group class membership. Future research should explore the role that circadian characteristics can play in defining sub-phenotypes of bipolar disorder.

Effect of Post-splenectomy Booster Vaccine Program on Vaccination Compliance in Trauma Patients.

OBJECTIVE: In 2012, the Centers for Disease Control and Prevention (CDC) Advisory Council on Immunization Practice recommended an additional post-splenectomy booster vaccine at 8 weeks following the initial vaccine. The objective of this study was to evaluate our vaccination compliance rate and what sociodemographic factors were associated with noncompliance following this recommendation. MATERIALS AND METHODS: A retrospective review of a performance improvement database of trauma patients eligible for post-splenectomy vaccination (PSV) at a level I trauma center was carried out between 2009 and 2018. Overall and institutional compliance with PSV was compared before and after the addition of booster vaccine recommendation. Factors associated with booster noncompliance were also identified. RESULTS: A total of 257 patients were identified. PSV compliance rate in the pre-booster was 98.4%, while overall and institutional post-booster compliance rate were significantly lower at 66.9% (P ≤ .001) and 50.0% (P ≤ .001), respectively. Compared to booster institutional compliers, institutional noncompliers lived farther from the trauma center (48 vs. 86 miles, P = .02), and though not statistically significant, these patients were generally older (34.9 vs. 40.5, P = .05). DISCUSSION: PSV booster compliance is low even with the current educational materials and recommendations. Additional approaches to improve compliance rates need to be implemented, such as sending letters to the patient and their primary care providers (PCPs), collaborating with rehab/long-term acute care centers, communicating with city and county health departments and city pharmacies, or mirroring other countries and creating a national database for asplenic patients to provide complete information.

Characteristics and clinical outcomes of patients hospitalized with laboratory-confirmed COVID-19-Puerto Rico, March-August 2020.

Hispanics are the majority ethnic population in Puerto Rico where we reviewed charts of 109 hospitalized COVID-19 patients to better understand demographic and clinical characteristics of COVID-19 and determine risk factors for poor outcomes. Eligible medical records of hospitalized patients with confirmed COVID-19 illnesses were reviewed at four participating hospitals in population centers across Puerto Rico and data were abstracted that described the clinical course, interventions, and outcomes. We found hospitalized patients had a median of 3 underlying conditions with obesity and diabetes as the most frequently reported conditions. Intensive care unit (ICU) admission occurred among 28% of patients and 18% of patients died during the hospitalization. Patients 65 or older or with immune deficiencies had a higher risk for death. Common symptoms included cough, dyspnea, and fatigue; less than half of patients in the study reported fever which was less frequent than reported elsewhere in the literature. It is important for interventions within Hispanic communities to protect high-risk groups.

The great big alveolar TI cell: evolving concepts and paradigms.

Pulmonary alveolar type I cells (TI cell) are very large (approximately 5400 microm(2) in surface area) squamous cells that cover more than 98% of the internal surface area of rodent lungs. In the past, TI cells were believed to serve only passive barrier functions, with no active functional properties in the lung. The fairly recent development of methods to isolate TI cells has permitted investigation of functions of this cell type for the first time. Resolvable by electron microscopy, TI cells contain microvilli and organelles typically associated with metabolic functions, such as mitochondria, abundant smooth and rough endoplasmic reticulum and Golgi apparatus. TI cells contain the molecular machinery necessary for ion transport and take up Na(+), K(+), and Cl(-), from which one can infer that it is likely that they play a role in ion and fluid transport in vivo. Because the abundance/microm(2) of highly selective Na(+) channels (HSC channels, consisting of all three ENaC subunits) is the same in TI and TII cells and because TI cells cover the majority of the lung internal surface, TI cells may play the major role in bulk transport of Na(+). In vitro, TI cells can proliferate and exhibit phenotypic plasticity, raising the question of whether this cell type may play a role in development and lung repair after injury. From gene expression analysis of TI cells, one can infer a variety of other possible functions for TI cells. The development of techniques to administer transgenes specifically to TI cells will permit direct study of this cell type in vivo.

The yin and yang of VEGF and PEDF: multifaceted neurotrophic factors and their potential in the treatment of Parkinson's Disease.

Over the last few decades, vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) have emerged as multifaceted players in not only the pathogenesis, but potential treatment, of numerous diseases. They activate diverse intracellular signaling cascades known to have extensive crosstalk, and have been best studied for their effects in cardiology and cancer biology. Recent work with the two factors indicates that the activity of one growth factor is often directly related to the action of the other. Their respective neuroprotective effects, in particular, raise important questions regarding the treatment of neurodegenerative disorders, including Parkinson's disease.

Using Chronobiological Phenotypes to Address Heterogeneity in Bipolar Disorder.

Bipolar disorder (BD) is a neuropsychiatric mood disorder characterized by recurrent episodes of mania and depression in addition to disruptions in sleep, energy, appetite, and cognitive functions-rhythmic behaviors that typically change on daily cycles. BD symptoms can also be provoked by seasonal changes, sleep, and/or circadian disruption, indicating that chronobiological factors linked to the circadian clock may be a common feature in the disorder. Research indicates that BD exists on a clinical spectrum, with distinct subtypes often intersecting with other psychiatric disorders. This heterogeneity has been a major challenge to BD research and contributes to problems in diagnostic stability and treatment outcomes. To address this heterogeneity, we propose that chronobiologically related biomarkers could be useful in classifying BD into objectively measurable phenotypes to establish better diagnoses, inform treatments, and perhaps lead to better clinical outcomes. Presently, we review the biological basis of circadian time keeping in humans, discuss the links of BD to the circadian clock, and pre-sent recent studies that evaluated chronobiological measures as a basis for establishing BD phenotypes. We conclude that chronobiology may inform future research using other novel techniques such as genomics, cell biology, and advanced behavioral analyses to establish new and more biologically based BD phenotypes.

Rat alveolar type I cells proliferate, express OCT-4, and exhibit phenotypic plasticity in vitro.

Alveolar type I (TI) cells are large, squamous cells that cover 95-99% of the internal surface area of the lung. Although TI cells are believed to be terminally differentiated, incapable of either proliferation or phenotypic plasticity, TI cells in vitro both proliferate and express phenotypic markers of other differentiated cell types. Rat TI cells isolated in purities of >99% proliferate in culture, with a sixfold increase in cell number before the cells reach confluence; >50% of the cultured TI cells are Ki67+. At cell densities of 1-2 cells/well, approximately 50% of the cells had the capacity to form colonies. Under the same conditions, type II cells do not proliferate. Cultured TI cells express RTI40 and aquaporin 5, phenotypic markers of the TI cell phenotype. By immunofluorescence, Western blotting, and Q-PCR, TI cells express OCT-4A (POU5F1), a transcription factor associated with maintenance of the pluripotent state in stem cells. Based on the expression patterns of various marker proteins, TI cells are distinct from either of two recently described putative pulmonary multipotent cell populations, the bronchoalveolar stem cell or the OCT-4+ stem/progenitor cell. Although TI cells in adult rat lung tissue do not express either surfactant protein C (SP-C) or CC10, respective markers of the TII and Clara cell phenotypes, in culture TI cells can be induced to express both SP-C and CC10. Together, the findings that TI cells proliferate and exhibit phenotypic plasticity in vitro raise the possibility that TI cells may have similar properties in vivo.

Pharmacological Manipulation of the Circadian Clock: A Possible Approach to the Management of Bipolar Disorder.

Bipolar disorder (BD) is a mood disorder with genetic and neurobiological underpinnings, characterized primarily by recurrent episodes of mania and depression, with notable disruptions in rhythmic behaviors such as sleep, energy, appetite and attention. The chronobiological links to BD are further supported by the effectiveness of various treatment modalities such as bright light, circadian phase advance, and mood-stabilizing drugs such as lithium that have effects on the circadian clock. Over the past 30 years, the neurobiology of the circadian clock has been exquisitely described and there now exists a detailed knowledge of key signaling pathways, neurotransmitters and signaling mechanisms that regulate various dimensions of circadian clock function. With this new wealth of information, it is becoming increasingly plausible that new drugs for BD could be made by targeting molecular elements of the circadian clock. However, circadian rhythms are multidimensional and complex, involving unique, time-dependent factors that are not typically considered in drug development. We review the organization of the circadian clock in the central nervous system and briefly summarize data implicating the circadian clock in BD. We then consider some of the unique aspects of the circadian clock as a drug target in BD, discuss key methodological considerations and evaluate some of the candidate clock pathways and systems that could serve as potential targets for novel mood stabilizers. We expect this work will serve as a roadmap to facilitate the development of compounds acting on the circadian clock for the treatment of BD.

Removal of retrievable inferior vena cava filters before discharge: Is it associated with increased incidence of pulmonary embolism?

BACKGROUND: Severely injured trauma patients are at high risk of developing deep venous thrombosis and pulmonary emboli (PE), and may have contraindications to prophylactic or therapeutic anticoagulation. Retrievable inferior vena cava filters (rIVCFs) are used to act as a mechanical obstruction to prevent PE in high risk populations and those with deep venous thrombosis who cannot be anticoagulated. The removal rate of rIVCFs is variable in trauma centers, including our previous published rate of 50% to 89%/year. Indwelling filters carry a risk of significant morbidity and the success of retrieval decreases as the dwell time increases. We hypothesized that once patients could receive appropriate prophylactic or therapeutic anticoagulation, rIVCF could be removed before hospital discharge without impact on occurrence or recurrence of PE. METHODS: All trauma patients with rIVCF placed and removed between January 2006 and August 2018 were reviewed. We collected data from record review from admission to 6 months postfilter removal, including demographics, filter indication, filter type, dwell time, placement and removal complications, antithrombosis medications, location of venous thromboembolism, complications, and discharge disposition. Exposure of interest was timing of filter removal: before (BEF) or after hospital discharge (AFT). The outcome of interest was whether the patient had a documented PE within 6 months of filter removal. RESULTS: A total of 281 rIVCFs were placed, 218 were eligible for removal, 72.4% (158/218) were retrieved with 63% (100/158) removed before discharge. Mean filter duration was 26 days and 103 days for the before and after groups, respectively. No differences (p > 0.05) were noted in the distribution of demographic and clinical factors except for filter indication (venous thromboembolism indication, 95% in AFT vs. 74% in BEF, p = 0.0043). Postremoval PE rates were 0% BEF and 1% AFT (Fisher's exact test, p = 1.000). CONCLUSION: Our results suggest that removal of rIVCFs before discharge once patients are appropriately anticoagulated is a safe strategy to improve retrieval rates. LEVEL OF EVIDENCE: Therapeutic, level V.

Directed expression of transgenes to alveolar type I cells in the mouse.

Podoplanin (RTI40, aggrus, T1alpha, hT1alpha-2, E11, PA2.26, RANDAM-2, gp36, gp38, gp40, OTS8) is a type I cell marker in rat lung. We show that a bacterial artificial chromosome vector containing the rat podoplanin gene (RTIbac) delivers a pattern of transgene expression in lung that is more restricted to mouse type I cells than that of the endogenous mouse podoplanin gene. RTIbac-transgenic mice expressed rat podoplanin in type I cells; type II cells, airways, and vascular endothelium were negative. A modified bacterial artificial chromosome containing internal ribosome entry site (IRES)-green fluorescent protein (GFP) sequences in the podoplanin 3'UTR expressed rat podoplanin and transgenic GFP in type I cells. RTIbac transgene expression was absent or reduced in pulmonary pleura, lymphatic endothelium, and putative lymphoid-associated stromal tissue, all of which contained abundant mouse podoplanin. Rat podoplanin mRNA levels in normal rat lung and RTIbac transgenic lung were 25-fold higher than in corresponding kidney and brain samples. On Western blots, transgenic rat and endogenous mouse podoplanin displayed very similar patterns of protein expression in various organs. Highest protein levels were observed in lung with 10- to 20-fold less in brain; there were low levels in thymus and kidney. Both GFP and rat podoplanin transgenes were expressed at extrapulmonary sites of endogenous mouse podoplanin gene expression, including choroid plexus, eye ciliary epithelium, and renal glomerulus. Because their pulmonary expression is more restricted than endogenous mouse podoplanin, RTIbac derivatives should be useful for mouse type I cell-specific transgene delivery.