Low-dose computed tomography scan and biopsy for assessing lung cancer prevalence and related factors in high-risk populations.

Background: Lung cancer is the second most diagnosed cancer and the leading cause of cancer death in 2020, representing approximately one in 10 (11.4 %) cancers diagnosed and one in 5 (18.0 %) deaths. There are currently very few studies evaluating the prevalence and related factors of lung cancer detected using low-dose CT scans. Objective: Evaluate the prevalence and related factors of lung cancer using low-dose CT scans in high-risk populations in Vietnam. Materials and methods: A cross-sectional analysis study of 169 high-risk patients was conducted to assess the lung cancer prevalence and related factors. Enrolled patients received a physical examination, low-dose computerized tomography scan, and biopsy if abnormalities were found through the CT scan. Univariable and Multivariable analysis through Odd Ratio (OR) to assess the related risk of lung cancer. Results: A total of 169 high-risk patients with a mean age of 62.93 ± 9.31 (years), and the majority were male (91.7 %). Of which 4 cases (2.37 %) were recorded with lung cancer, 3 cases of adenocarcinoma, and 1 case of squamous cell carcinoma. A history of smoking and Chronic Obstructive Pulmonary Disease (COPD) were associated with an increased risk of abnormalities on lung CT scans. Multivariate regression analysis revealed that smoking over 30 pack-years and COPD significantly increased the risk of abnormalities on lung CT scans, p < 0.05.100 % of lung cancer-detected cases were male and smoking ≥30 pack - years. Conclusion: The prevalence of lung cancer in the Vietnamese high-risk population was relatively high. Relative factors such as smoking ≥30 pack - years, and COPD had increased risk of CTscan abnormalities.

Prevalence of SARS-CoV-2 infection among people experiencing homelessness in Toronto during the first wave of the COVID-19 pandemic.

OBJECTIVES: People experiencing homelessness are at increased risk of SARS-CoV-2 infection. This study reports the point prevalence of SARS-CoV-2 infection during testing conducted at sites serving people experiencing homelessness in Toronto during the first wave of the COVID-19 pandemic. We also explored the association between site characteristics and prevalence rates. METHODS: The study included individuals who were staying at shelters, encampments, COVID-19 physical distancing sites, and drop-in and respite sites and completed outreach-based testing for SARS-CoV-2 during the period April 17 to July 31, 2020. We examined test positivity rates over time and compared them to rates in the general population of Toronto. Negative binomial regression was used to examine the relationship between each shelter-level characteristic and SARS-CoV-2 positivity rates. We also compared the rates across 3 time periods (T1: April 17-April 25; T2: April 26-May 23; T3: May 24-June 25). RESULTS: The overall prevalence of SARS-CoV-2 infection was 8.5% (394/4657). Site-specific rates showed great heterogeneity with infection rates ranging from 0% to 70.6%. Compared to T1, positivity rates were 0.21 times lower (95% CI: 0.06-0.75) during T2 and 0.14 times lower (95% CI: 0.04-0.44) during T3. Most cases were detected during outbreak testing (384/394 [97.5%]) rather than active case finding. CONCLUSION: During the first wave of the pandemic, rates of SARS-CoV-2 infection at sites for people experiencing homelessness in Toronto varied significantly over time. The observation of lower rates at certain sites may be attributable to overall time trends, expansion of outreach-based testing to include sites without known outbreaks, and/or individual site characteristics.

RéSUMé: OBJECTIFS: Les personnes en situation d'itinérance courent un risque accru de contracter une infection par le SRAS-CoV-2. Notre étude rend compte de la prévalence ponctuelle des infections par le SRAS-CoV-2 au cours de tests de dépistage menés dans des lieux de services aux personnes en situation d'itinérance de Toronto au cours de la première vague de la pandémie de COVID-19. Nous avons aussi exploré l'association entre les caractéristiques de ces lieux et les taux de prévalence. MéTHODE: L'étude a inclus les personnes séjournant dans des refuges, des campements, des lieux de distanciation physique et des centres d'accueil et de répit et ayant subi un test de dépistage de proximité du SRAS-CoV-2 entre le 17 avril et le 31 juillet 2020. Nous avons examiné les taux de positivité des tests au fil du temps et nous les avons comparés aux taux dans la population générale de Toronto. Des analyses de régression binomiales négatives ont été effectuées pour étudier la relation entre chaque caractéristique au niveau des refuges et les taux de positivité au SRAS-CoV-2. Nous avons aussi comparé les taux de trois intervalles (I1: 17 au 25 avril; I2: 26 avril au 23 mai; I3: 24 mai au 25 juin). RéSULTATS: La prévalence globale des infections par le SRAS-CoV-2 était de 8,5 % (394/4 657). Les taux d'infection spécifiques aux lieux de services ont présenté une grande hétérogénéité, soit de 0 % à 70,6 %. Comparés au 1er intervalle (I1), les taux de positivité ont été 0,21 fois plus faibles (IC de 95% : 0,06 ­ 0,75) durant l'I2 et 0,14 fois plus faibles (IC de 95% : 0,04 ­ 0,44) durant l'I3. La plupart des cas ont été détectés lors d'un dépistage en cours d'éclosion (384/394 [97,5%]) et non lors d'une recherche active de cas. CONCLUSION: Au cours de la première vague de la pandémie, les taux d'infection par le SRAS-CoV-2 dans les lieux de services aux personnes en situation d'itinérance de Toronto ont varié de façon significative au fil du temps. L'observation de taux plus faibles dans certains lieux pourrait s'expliquer par les tendances temporelles globales, par l'expansion des activités de dépistage de proximité pour inclure les lieux sans éclosion connue et/ou par les caractéristiques individuelles des lieux.

Socio-ecological correlates of neophobia in corvids.

Behavioral responses to novelty, including fear and subsequent avoidance of novel stimuli, i.e., neophobia, determine how animals interact with their environment. Neophobia aids in navigating risk and impacts on adaptability and survival. There is variation within and between individuals and species; however, lack of large-scale, comparative studies critically limits investigation of the socio-ecological drivers of neophobia. In this study, we tested responses to novel objects and food (alongside familiar food) versus a baseline (familiar food alone) in 10 corvid species (241 subjects) across 10 labs worldwide. There were species differences in the latency to touch familiar food in the novel object and novel food conditions relative to the baseline. Four of seven socio-ecological factors influenced object neophobia: (1) use of urban habitat (versus not), (2) territorial pair versus family group sociality, (3) large versus small maximum flock size, and (4) moderate versus specialized caching (whereas range, hunting live animals, and genus did not), while only maximum flock size influenced food neophobia. We found that, overall, individuals were temporally and contextually repeatable (i.e., consistent) in their novelty responses in all conditions, indicating neophobia is a stable behavioral trait. With this study, we have established a network of corvid researchers, demonstrating potential for further collaboration to explore the evolution of cognition in corvids and other bird species. These novel findings enable us, for the first time in corvids, to identify the socio-ecological correlates of neophobia and grant insight into specific elements that drive higher neophobic responses in this avian family group. VIDEO ABSTRACT.

Adverse childhood experiences and related outcomes among adults experiencing homelessness: a systematic review and meta-analysis.

BACKGROUND: Adverse childhood experiences (ACEs) are strong risk factors for homelessness and poor health and functioning. We aimed to evaluate the lifetime prevalence of ACEs and their associations with health-related and functioning-related outcomes among homeless adults. METHODS: In this systematic review and meta-analysis, we searched from database inception to Nov 11, 2020, for original and peer-reviewed studies in English that documented lifetime prevalence of ACEs or associations between ACEs and health-related or functioning-related outcomes. We selected studies if they included a definable group of homeless adults and measured at least four ACE categories. We calculated pooled estimates of lifetime prevalence of one or more ACEs and four or more ACEs with random-effects models. We used the leave-one-out method in sensitivity analyses and studied meta-regressions to explore potential moderators of ACE prevalence. We also did a narrative summary of associations between ACEs and health-related and functioning-related outcomes, as there were too few studies on each outcome for quantitative meta-analysis. This study is registered with PROSPERO, CRD42020218741. FINDINGS: We identified 2129 studies through systematic search, of which 29 studies (16 942 individuals) were included in the systematic review, 20 studies (10 034 individuals) were included in the meta-analysis for one or more ACEs, and 15 studies (5693 individuals) were included in the meta-analysis for four or more ACEs. Studies included samples of adults experiencing homelessness in the USA, Canada, and the UK; participants in the included studies were predominantly male (65·2%) and mean ages ranged between 18·3 and 58·1 years, but many studies did not report race, ethnicity, and sexual and gender minority data. Lifetime prevalence of one or more ACEs among homeless adults was 89·8% (95% CI 83·7-93·7) and the lifetime prevalence of four or more ACEs was 53·9% (45·9-61·7). Considerable heterogeneity was identified in both meta-analyses (I2>95%). Of the potential moderators analysed, the ACE measurement tool significantly moderated the estimated lifetime prevalence of one or more ACEs and four or more ACEs, and age also significantly moderated the estimated lifetime prevalence of four or more ACEs. In the narrative synthesis, ACEs were consistently positively associated with high suicidality (two studies), suicide attempt (three studies), major depressive disorder (two studies), substance misuse (two studies), and adult victimisation (two studies). INTERPRETATION: The lifetime prevalence of ACEs is substantially higher among homeless adults than among the general population, and ACE exposure might be associated with prevalence of mental illness, substance misuse, and victimisation. Policy efforts and evidence-based interventions are urgently needed to prevent ACEs and address associated poor outcomes among this population. FUNDING: Rhodes Trust and Canadian Institutes of Health Research.

Clinical Presentation and Outcome of Patients Experiencing Homelessness Presenting With ST-Segment Elevation Myocardial Infarction.

BACKGROUND: Cardiovascular disease remains a major cause of morbidity and mortality among homeless adults. Despite major advances in the management of ST elevation myocardial infarction (STEMI), limited information is available for the clinical presentation and management and outcome of STEMI among patients experiencing homelessness (PEH). METHODS: All patients presenting with STEMI between January 1, 2008 and December 31, 2017 at a PCI capable STEMI network inner city hospital comprised the study population. Baseline characteristics, homeless status and clinical outcomes were determined from hospital records. The primary outcome of in-hospital mortality was compared between PEH and nonhomeless patients using a log-binomial regression model with propensity score adjusted standardised mortality ratio weighting (SMRW). RESULTS: Among 2854 STEMI admissions during the study period, 75 patients (2.6%) were identified as PEH. The PEH group was younger (58 vs 63 years; P = 0.0002), predominantly male (96% vs 76%), and more likely to present with cardiogenic shock or cardiac arrest (17% vs 6%) compared with the nonhomeless group. The in-hospital mortality remained significantly higher among PEH (risk ratio 3.83, 95% confidence interval 1.27-11.60) after propensity score adjustment. CONCLUSIONS: Despite universal health care and contemporary STEMI management, PEH presenting with STEMI experienced a 4-fold higher in-hospital mortality compared with the nonhomeless cohort. Targeted interventions are needed to improve STEMI outcomes in this high-risk group.

The impact of a Housing First intervention and health-related risk factors on incarceration among people with experiences of homelessness and mental illness in Canada.

OBJECTIVE: To examine the effect of a Housing First (HF) intervention and health-related risk factors on incarceration among adults with experiences of homelessness and mental illness. METHODS: Participants (N = 508) were recruited at the Toronto site of the At Home/Chez Soi study. The outcome was incarceration in Ontario from 2009 to 2014. Exposures were intervention group (HF vs. treatment as usual), Axis I mental health diagnoses, emergency department (ED) visit, and history of traumatic brain injury (TBI). Logistic regression was used to examine the association between exposures and incarceration. RESULTS: Of 508 participants, 220 (43.3%) were incarcerated at least once during the study period. Among those incarcerated, 81.9% were male, 52.7% had been diagnosed with alcohol dependence/abuse, 60.9% had been diagnosed with substance dependence/abuse, 65.1% reported having visited an ED within the last 6 months, and 66.4% had a history of TBI. After adjusting for demographic covariates, substance dependence/abuse (aOR: 2.06; 95% CI: 1.40, 3.03), alcohol dependence/abuse (aOR: 1.52, 95% CI: 1.04, 2.22), ED visit (aOR: 1.54; 95% CI: 1.02, 2.32), and history of TBI (aOR: 2.60; 95% CI: 1.75, 3.85) were associated with incarceration. We found no significant effect of the HF intervention on incarceration outcome (aOR: 1.08; 95% CI: 0.76, 1.55). CONCLUSIONS: Among adults with experiences of homelessness and severe mental illness, those with substance and alcohol dependence/abuse disorders, history of TBI, and recent ED visits were at increased odds of incarceration. Strategies are needed to prevent and reduce incarceration for this population, including treatment of mental illness in the community.

RéSUMé: OBJECTIF: Examiner l'effet d'une intervention de Logement d'abord (LD) et de facteurs de risque liés à la santé sur l'incarcération d'adultes ayant vécu des épisodes de sans-abrisme et de maladie mentale. MéTHODE: Les participants (N = 508) ont été recrutés sur le site torontois de l'étude At Home/Chez-Soi. L'issue à l'étude était l'incarcération en Ontario entre 2009 et 2014. Les expositions étaient le groupe d'intervention (LD vs. traitement habituel), les diagnostics de troubles de santé mentale de l'axe I, les visites aux services d'urgence (SU) et les antécédents de traumatisme cranio-cérébral (TCC). Nous avons procédé par régression logistique pour examiner l'association entre les expositions et l'incarcération. RéSULTATS: Sur 508 participants, 220 (43,3 %) avaient été incarcérés au moins une fois durant la période de l'étude. Chez les personnes incarcérées, 81,9 % étaient des hommes, 52,7 % avaient un diagnostic de dépendance à l'alcool ou d'abus d'alcool, 60,9 % avaient un diagnostic de dépendance à des substances ou d'abus de substances, 65,1 % ont dit avoir visité les SU au cours des 6 mois antérieurs, et 66,4 % avaient des antécédents de TCC. Après ajustement en fonction des covariables démographiques, la dépendance aux substances/l'abus de substances (rapport de cotes ajusté [RCa] : 2,06; IC de 95 % : 1,40, 3,03), la dépendance à l'alcool/l'abus d'alcool (RCa : 1,52, IC de 95 % : 1,04, 2,22), les visites aux SU (RCa : 1,54; IC de 95 % : 1,02, 2,32) et les antécédents de TCC (RCa : 2,60; IC de 95 % : 1,75, 3,85) étaient associés à l'incarcération. Nous n'avons observé aucun effet significatif de l'intervention de LD sur l'issue d'incarcération (RCa : 1,08; IC de 95 % : 0,76, 1,55). CONCLUSIONS: Chez les adultes ayant vécu des épisodes de sans-abrisme et de maladie mentale grave, ceux qui avaient des troubles de dépendance/d'abus de substances et d'alcool, des antécédents de TCC et qui avaient visité les SU récemment présentaient une probabilité accrue d'incarcération. Il faut des stratégies pour prévenir et réduire l'incarcération dans cette population, y compris des stratégies de traitement des maladies mentales hors du milieu carcéral.

Impact of cigarette tax increase on health and financing outcomes in four Indian states.

Background: In India, about one million deaths occur every year due to smoking. Tobacco taxation is the most effective intervention in reducing smoking. In this paper, we examine the impact of a one-time large cigarette price increase, through an increase in excise tax, on health and financing outcomes in four Indian states. Methods: We used extended cost-effectiveness analysis to estimate, across income quintiles, the life-years gained, treatment cost averted, number of men avoiding catastrophic health expenditures and extreme poverty, additional tax revenue collected, and savings to the Ayushman Bharat Pradhan Mantri Jan Arogya Yojana (AB-PMJAY) with a cigarette price increase to Indian Rupees (INR) 10 plus 10% ad valorem in four Indian states. Results: With the price increase, about 1.5 million men would quit smoking across the four states, with the bottom income group having 7.4 times as many quitters as the top income group (485,725 vs 65,762). As a result of quitting, about 665,000 deaths would be averted. This would yield about 11.9 million life-years, with the bottom income group gaining 7.3 times more than the top income group. Of the INR 1,729 crore in treatment cost averted, the bottom income group would avert 7.4 times more than the top income group. About 454,000 men would avoid catastrophic health expenditures and 75,000 men would avoid falling into extreme poverty. The treatment cost and impoverishment averted would save about INR 672 crore in AB-PMJAY. The tax increase would in turn, generate an additional tax revenue of about INR 4,385 crore. In contrast to the distribution of health benefits, the extra revenue generated from the top income group would be about 3.1 times that from the bottom income group. Conclusions: Cigarette tax increase can provide significant health and economic gains and is a pro-poor policy for India.

Heterogeneity in testing, diagnosis and outcome in SARS-CoV-2 infection across outbreak settings in the Greater Toronto Area, Canada: an observational study.

BACKGROUND: Congregate settings have been disproportionately affected by coronavirus disease 2019 (COVID-19). Our objective was to compare testing for, diagnosis of and death after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection across 3 settings (residents of long-term care homes, people living in shelters and the rest of the population). METHODS: We conducted a population-based prospective cohort study involving individuals tested for SARS-CoV-2 in the Greater Toronto Area between Jan. 23, 2020, and May 20, 2020. We sourced person-level data from COVID-19 surveillance and reporting systems in Ontario. We calculated cumulatively diagnosed cases per capita, proportion tested, proportion tested positive and case-fatality proportion for each setting. We estimated the age- and sex-adjusted rate ratios associated with setting for test positivity and case fatality using quasi-Poisson regression. RESULTS: Over the study period, a total of 173 092 individuals were tested for and 16 490 individuals were diagnosed with SARS-CoV-2 infection. We observed a shift in the proportion of cumulative cases from all cases being related to travel to cases in residents of long-term care homes (20.4% [3368/16 490]), shelters (2.3% [372/16 490]), other congregate settings (20.9% [3446/16 490]) and community settings (35.4% [5834/16 490]), with cumulative travel-related cases at 4.1% (674/16490). Cumulatively, compared with the rest of the population, the diagnosed cases per capita was 64-fold and 19-fold higher among long-term care home and shelter residents, respectively. By May 20, 2020, 76.3% (21 617/28 316) of long-term care home residents and 2.2% (150 077/6 808 890) of the rest of the population had been tested. After adjusting for age and sex, residents of long-term care homes were 2.4 (95% confidence interval [CI] 2.2-2.7) times more likely to test positive, and those who received a diagnosis of COVID-19 were 1.4-fold (95% CI 1.1-1.8) more likely to die than the rest of the population. INTERPRETATION: Long-term care homes and shelters had disproportionate diagnosed cases per capita, and residents of long-term care homes diagnosed with COVID-19 had higher case fatality than the rest of the population. Heterogeneity across micro-epidemics among specific populations and settings may reflect underlying heterogeneity in transmission risks, necessitating setting-specific COVID-19 prevention and mitigation strategies.

The Complete Genome Sequence of the Staphylococcus Bacteriophage Metroid.

Phages infecting bacteria of the genus Staphylococcus play an important role in their host's ecology and evolution. On one hand, horizontal gene transfer from phage can encourage the rapid adaptation of pathogenic Staphylococcus enabling them to escape host immunity or access novel environments. On the other hand, lytic phages are promising agents for the treatment of bacterial infections, especially those resistant to antibiotics. As part of an ongoing effort to gain novel insights into bacteriophage diversity, we characterized the complete genome of the Staphylococcus bacteriophage Metroid, a cluster C phage with a genome size of 151kb, encompassing 254 predicted protein-coding genes as well as 4 tRNAs. A comparative genomic analysis highlights strong similarities - including a conservation of the lysis cassette - with other Staphylococcus cluster C bacteriophages, several of which were previously characterized for therapeutic applications.

Insights from Drosophila melanogaster model of Alzheimer's disease.

Alzheimer's disease (AD) is a common chronic neurodegenerative disease that mainly affects the medial temporal lobe and associated neocortical structures. The disease process involves two abnormal structures, plaques and tangles, which damage and destroy nerve cells. Tangles are twisted fibers of tau protein that build up inside cells. Plaques are deposits of a protein fragment called amyloid-beta (Aß) that accumulate in the spaces between nerve cells. Aß derives from the amyloid precursor protein and is the main component of amyloid plaques in the AD brain. Although AD has been extensively examined, its pathogenetic mechanisms remain unclear and there are currently no effective drugs for this disorder. Many AD model systems have recently been established using Drosophila melanogaster by expressing the proteins involved in AD in the brain. These systems successfully reflect some of the symptoms associated with AD such as the onset of learning defects, age-dependent short-term memory impairment, increase of wakefulness and consolidated sleep disruption by expressing human Aß42 or human APP/BACE in Drosophila central nervous system. We herein discuss these Drosophila AD models.

Cold Weather Conditions and Risk of Hypothermia Among People Experiencing Homelessness: Implications for Prevention Strategies.

Hypothermia is a preventable condition that disproportionately affects individuals who experience homelessness, yet limited data exist to inform the response to cold weather. To fill this gap, we examined the association between meteorological conditions and the risk of hypothermia among homeless individuals. Hypothermic events were identified from emergency department charts and coroner's records between 2004 and 2015 in Toronto, Canada. A time-stratified case-crossover design with conditional logistic regression was used to assess the relationship between the meteorological conditions (minimum temperature and precipitation) and the risk of hypothermia. There were 97 hypothermic events identified: 79 injuries and 18 deaths. The odds of experiencing a hypothermic event increased 1.64-fold (95% CI: 1.30-2.07) with every 5 °C decrease in the minimum daily temperature and 1.10-fold (95% CI: 1.03-1.17) with every 1 mm increase in precipitation. The risk of hypothermia among individuals experiencing homelessness increased with declining temperature; however, most cases occurred during periods of low and moderate cold stress. 72% occurred when the minimum daily temperatures were warmer than -15 °C. These findings highlight the importance of providing a seasonal cold weather response to prevent hypothermia, complemented by an alert-based response on extremely cold days.

The Effect of Advance Directive Completion on Hospital Care Among Chronically Homeless Persons: a Prospective Cohort Study.

Advance care planning is relevant for homeless individuals because they experience high rates of morbidity and mortality. The impact of advance directive interventions on hospital care of homeless individuals has not been studied. The objective of this study was to determine if homeless individuals who complete an advance directive through a shelter-based intervention are more likely to have information from their advance directive documented and used during subsequent hospitalizations. The advance directive included preferences for life-sustaining treatments, resuscitation, and substitute decision maker(s). A total of 205 homeless men from a homeless shelter for men in Toronto, Canada, were enrolled in the study and offered an opportunity to complete an advance directive with the guidance of a trained counselor from April to June 2013. One hundred and three participants chose to complete an advance directive, and 102 participants chose to not complete an advance directive. Participants were provided copies of their advance directives. In addition, advance directives were electronically stored, and hospitals within a 1.0-mile radius of the shelter were provided access to the database. A prospective cohort study was performed using chart reviews to ascertain the documentation, availability, and use of advance directives, end-of-life care preferences, and medical treatments during hospitalizations over a 1-year follow-up period (April 2013 to June 2014) after the shelter-based advance directive intervention. Chart reviewers were blinded as to whether participants had completed an advance directive. The primary outcome was documentation or use of an advance directive during any hospitalization. The secondary outcome was documentation of end-of-life care preferences, without reference to an advance directive, during any hospitalization. After unblinding, charts were studied to determine whether advance directives were available, hospital care was consistent with patient preferences as documented in advance directives, and hospital resource utilization during admission. During the 1-year follow-up period, 38 participants who completed an advance directive and 37 participants who did not complete an advance directive had at least one hospitalization (36.9 vs. 36.2 %, p = 0.93). Participants who completed an advance directive were significantly more likely to have documentation or use of an advance directive in hospital, compared to participants who did not complete an advance directive (9.7 vs. 2.9 %, p = 0.047). Without reference to an advance directive, documentation of end-of-life care preferences occurred in 30.1 vs. 30.4 % of participants, respectively (p = 0.96), most often due to documentation of code status. There were no significant differences in resource utilization between admitted patients who completed and did not complete an advance directive. In conclusion, homeless men who complete an advance directive through a shelter-based intervention are more likely to have their detailed care preferences documented or used during subsequent hospitalizations.

NF-Y in invertebrates.

Both Drosophila melanogaster and Caenorhabditis elegans (C. elegans) are useful model organisms to study in vivo roles of NF-Y during development. Drosophila NF-Y (dNF-Y) consists of three subunits dNF-YA, dNF-YB and dNF-YC. In some tissues, dNF-YC-related protein Mes4 may replace dNF-YC in dNF-Y complex. Studies with eye imaginal disc-specific dNF-Y-knockdown flies revealed that dNF-Y positively regulates the sevenless gene encoding a receptor tyrosine kinase, a component of the ERK pathway and negatively regulates the Sensless gene encoding a transcription factor to ensure proper development of R7 photoreceptor cells together with proper R7 axon targeting. dNF-Y also controls the Drosophila Bcl-2 (debcl) to regulate apoptosis. In thorax development, dNF-Y is necessary for both proper Drosophila JNK (basket) expression and JNK signaling activity that is responsible for thorax development. Drosophila p53 gene was also identified as one of the dNF-Y target genes in this system. C. elegans contains two forms of NF-YA subunit, CeNF-YA1 and CeNF-YA2. C. elegans NF-Y (CeNF-Y) therefore consists of CeNF-YB, CeNF-YC and either CeNF-YA1 or CeNF-YA2. CeNF-Y negatively regulates expression of the Hox gene egl-5 (ortholog of Drosophila Abdominal-B) that is involved in tail patterning. CeNF-Y also negatively regulates expression of the tbx-2 gene that is essential for development of the pharyngeal muscles, specification of neural cell fate and adaptation in olfactory neurons. Negative regulation of the expression of egl-5 and tbx-2 by CeNF-Y provides new insight into the physiological meaning of negative regulation of gene expression by NF-Y during development. In addition, studies on NF-Y in platyhelminths are also summarized. This article is part of a Special Issue entitled: Nuclear Factor Y in Development and Disease, edited by Prof. Roberto Mantovani.

Nuclear transcription factor Y and its roles in cellular processes related to human disease.

Nuclear transcription factor Y (NF-Y) is an example of a transcriptional regulation factor in eukaryotes consisting of three different subunits, NF-YA, NF-YB and NF-YC, which are all necessary for formation of NF-Y complexes and binding to CCAAT boxes in promoters of its target genes. Highly conserved between human and Drosophila, NF-Y regulates transcription of various genes related to the cell cycle and various human diseases. Drosophila models have been widely used as tools for studying genetics and developmental biology and more recently for analyzing the functions of human disease genes, including those responsible for developmental and neurological disorders, cancer, cardiovascular disease and metabolic and storage diseases, as well as genes required for function of the visual, auditory and immune systems. In this review, in vivo findings from Drosophila models relevant to the roles of NF-Y in various human diseases are summarized. Recent studies have demonstrated novel contributions of dNF-Y to apoptosis and apoptosis-induced proliferation, and in photoreceptor cell differentiation during the development of the Drosophila compound eye.

Desmoplastic small round cell tumor (DSRCT) xenografts and tissue culture lines: Establishment and initial characterization.

Desmoplastic small round cell tumor (DSRCT) is an extremely rare and aggressive neoplasm, which mainly affects young males and generally presents as a widely disseminated tumor within the peritoneal cavity. Due to the rarity of the tumor, its younger and overall healthier patient population (compared with other tumor types) and the fact that it lacks definitive histological and immunohistological features, the diagnosis of DSRCT may be frequently delayed or the tumor may be entirely misdiagnosed as a different type of abdominal sarcoma. The present study aimed to rectify the lack of models that exist for this rare neoplasm, through the development of several DSRCT tissue cultures and xenograft lines. Samples were received from surgeries and biopsies from patients worldwide and were immediately processed for xenograft development in nude mice. Tumor tissues were minced and fragments were injected into the dorsal flanks of nude mice. Of the 14 samples received, nine were established into xenograft lines and five into tissue culture lines. Xenografts displayed the microscopic histology of their parent tumors and demonstrated two different growth rates among the established xenograft lines. Overall, the establishment of these xenograft and tissue culture lines provides researchers with tools to evaluate DSRCT responses to chemotherapy and to investigate DSRCT-specific signaling pathways or mechanisms.

dNF-YB plays dual roles in cell death and cell differentiation during Drosophila eye development.

Nuclear transcription factor Y (NF-Y) is well characterized in eukaryotes. It consists of three different subunits, NF-YA, NF-YB and NF-YC, all of which are required for formation of the NF-Y complex and DNA-binding. There is a high homology in NF-YB among Drosophila species with 75% identity and 95% similarity overall, especially in the histone-fold motif (HFM) (95% identity and 100% similarity). In the present study, specific knockdown of Drosophila NF-YB (dNF-YB) in eye imaginal discs induced a rough eye phenotype in adults and this phenotype was the result of induction of caspase-dependent apoptosis followed by apoptosis-induced proliferation. Furthermore, knockdown specifically inhibited R7 photoreceptor cell differentiation, independent of the apoptotic function. dNF-YB and dNF-YA indeed form complexes in vivo where they impair R7 photoreceptor cell differentiation by down regulating the mitogen-activated protein kinase (MAPK) pathway. Expression of the sev gene, or the D-raf gene, a downstream component of the MAPK cascade, could rescue the rough eye phenotype and the loss of R7 signals in dNF-YB knockdown flies. The death executioner Bcl-2 (debcl) is the homolog of Bcl-2 in Drosophila melanogaster and its promoter contains four dNF-Y-binding consensus sequences which play positive roles in promoter activity. In chromatin immunoprecipitation assays with anti-dNF-YB antibody and S2 cells, the debcl gene promoter region containing the NF-Y consensus was effectively amplified in immunoprecipitates by polymerase chain reaction. Taken together, these results indicate that dNF-Y regulates debcl gene expression.

Transcription factor NF-Y is involved in differentiation of R7 photoreceptor cell in Drosophila.

The CCAAT motif-binding factor NF-Y consists of three different subunits, NF-YA, NF-YB and NF-YC. Knockdown of Drosophila NF-YA (dNF-YA) in eye discs with GMR-GAL4 and UAS-dNF-YAIR resulted in a rough eye phenotype and monitoring of differentiation of photoreceptor cells by LacZ expression in seven up-LacZ and deadpan-lacZ enhancer trap lines revealed associated loss of R7 photoreceptor signals. In line with differentiation of R7 being regulated by the sevenless (sev) gene and the MAPK cascade, the rough eye phenotype and loss of R7 signals in dNF-YA-knockdown flies were rescued by expression of the sev gene, or the D-raf gene, a downstream component of the MAPK cascade. The sev gene promoter contains two dNF-Y-binding consensus sequences which play positive roles in promoter activity. In chromatin immunoprecipitation assays with anti-dNF-YA antibody and S2 cells, the sev gene promoter region containing the NF-Y consensus was effectively amplified in immunoprecipitates from transgenic flies by polymerase chain reaction, indicating that dNF-Y is necessary for appropriate sev expression and involved in R7 photoreceptor cell development.

Effects of Protein-Simulated Body Fluid Mixing Methods on Characteristics of Bone-Like Mineral.

This study examined effects of protein mixing methods into modified simulated body fluid (mSBF) on the crystalline structure and morphology of bone-like mineral (BLM) coated on poly(lactic-co-glycolic acid) PLGA. Using bovine serum albumin (BSA) as a model protein, four sample groups were prepared: the N-BLM group was coated by soaking substrates in mSBF without BSA; the B-BLM group was coated by soaking in mSBF with BSA added immediately before soaking; the Ca-BLM group was coated by soaking in Ca-mSBF prepared by premixing BSA with a CaCl(2) solution before preparing the mSBF; the P-BLM group was coated by soaking in P-mSBF made by premixing the BSA with a KH(2)PO(4) solution. The B-BLM and Ca-BLM groups exhibited densely coated, thick BLM layers, whereas the P-BLM group exhibited loosely connected BLM clusters. The hydroxyapatite (HAp) crystallites of the B-BLM and Ca-BLM groups were aligned along the c-axis, but those of the P-BLM group were disordered and had a lower crystallinity. The alignment to the c-axis of Ca-BLM and the disordered orientation of P-BLM was caused by calcium ions bound to BSA in Ca-mSBF and phosphate ions bound to BSA in P-mSBF, respectively. These results show that the crystallinity and morphology of BLM can be controlled by the mixing of BSA in mSBF. The crystallinity of BLM is closely connected to its solubility. Therefore, the release characteristics of growth factors and cell regulation on BLM could be affected by the changes in the crystalinity of BLM.

Effects of osteogenic growth factors on bone marrow stromal cell differentiation in a mineral-based delivery system.

Delivering growth factors from bone-like mineral combines osteoinductivity with osteoconductivity. The effects of individual and sequential exposure of BMP-2 and FGF-2 on osteogenic differentiation, and their release from apatite were studied to design a dual delivery system. Bone marrow stromal cells were seeded on TCPS with the addition of FGF-2 (2.5, 10, 40 ng/ml) or BMP-2 (50, 150, 450 ng/ml) for 6 days. DNA content and osteogenic response were examined weekly for 3 weeks. FGF-2 increased DNA content; however, high concentrations of FGF-2 inhibited/delayed osteogenic differentiation, while a threshold concentration of BMP-2 was required for significant osteogenic enhancement. The sequence of delivery of BMP-2 (300 ng/ml) and FGF-2 (2.5 ng/ml) also had a significant impact on osteogenic differentiation. Delivery of FGF-2 followed by BMP-2 or delivery of BMP-2 followed by BMP-2 and FGF-2 enhanced osteogenic differentiation compared to the simultaneous delivery of both factors. Release of BMP-2 and FGF-2 from bone-like mineral was significantly affected by the concentration used during coprecipitation. BMP-2 also demonstrated a higher "burst" release compared to FGF-2. By integrating the results of the sequential delivery of BMP-2 and FGF-2 in solution, with the release of individual growth factors from mineral, an organic/inorganic delivery system based on coprecipitation can be designed for multiple biomolecules.

Gene delivery via DNA incorporation within a biomimetic apatite coating.

Integrating inductivity with conductivity in a material may advance tissue engineering. An organic/inorganic hybrid was developed by incorporating plasmid DNA encoding for the beta-gal gene complexed with Lipofectamine 2000 (DNA-Lipoplex) within apatite via coprecipitation. It was hypothesized that this system will result in enhanced transfection efficiency compared to DNA-Lipoplexes adsorbed to the mineral surface and DNA coprecipitated without Lipofectamine 2000. PLGA films were cast onto glass slips and apatite and DNA were coprecipitated in modified simulated body fluid (mSBF). DNA-Lipoplex presence in mineral, DNA-Lipoplex stability (vs. coprecipitation time), and transfection efficiency (determined with C3H10T1/2 cells) as a function of coprecipitation time, DNA-Lipoplex concentration, and DNA incorporation method were studied. DNA-Lipoplex presence and spatial distribution on apatite were confirmed through fluorescence. Transfection efficiency was highest for 6h of DNA-Lipoplex coprecipitation. Differences in transfection efficiency were found between the DNA concentrations, with the highest efficiency for coprecipitation being 40 microg/ml (p < or = 0.009 relative to other coprecipitation concentrations). Significant differences in transfection efficiency existed between incorporation methods (p < 0.05) with the highest efficiency for DNA-Lipoplex coprecipitation. This hybrid material system not only integrates inductivity provided by the DNA and conductivity provided by the apatite, but it also has significant implications in non-viral gene delivery due to its ability to increase transfection efficiency.