Maternal tadalafil treatment does not increase uterine artery blood flow or oxygen delivery in the pregnant ewe.

Increasing placental perfusion (PP) could improve outcomes of growth-restricted fetuses. One way of increasing PP may be by using phosphodiesterase (PDE)-5 inhibitors, which induce vasodilatation of vascular beds. We used a combination of clinically relevant magnetic resonance imaging (MRI) techniques to characterize the impact that tadalafil infusion has on maternal, placental and fetal circulations. At 116-117 days' gestational age (dGA; term, 150 days), pregnant ewes (n = 6) underwent fetal catheterization surgery. At 120-123 dGA ewes were anaesthetized and MRI scans were performed during three acquisition windows: a basal state and then ∼15-75 min (TAD 1) and ∼75-135 min (TAD 2) post maternal administration (24 mg; intravenous bolus) of tadalafil. Phase contrast MRI and T2 oximetry were used to measure blood flow and oxygen delivery. Placental diffusion and PP were assessed using the Diffusion-Relaxation Combined Imaging for Detailed Placental Evaluation-'DECIDE' technique. Uterine artery (UtA) blood flow when normalized to maternal left ventricular cardiac output (LVCO) was reduced in both TAD periods. DECIDE imaging found no impact of tadalafil on placental diffusivity or fetoplacental blood volume fraction. Maternal-placental blood volume fraction was increased in the TAD 2 period. Fetal D O 2 ${D_{{{\mathrm{O}}_2}}}$ and V ̇ O 2 ${\dot V_{{{\mathrm{O}}_2}}}$ were not affected by maternal tadalafil administration. Maternal tadalafil administration did not increase UtA blood flow and thus may not be an effective vasodilator at the level of the UtAs. The increased maternal-placental blood volume fraction may indicate local vasodilatation of the maternal intervillous space, which may have compensated for the reduced proportion of UtA D O 2 ${D_{{{\mathrm{O}}_2}}}$ .

Wettability and Bactericidal Properties of Bioinspired ZnO Nanopillar Surfaces.

Nanomaterials of zinc oxide (ZnO) exhibit antibacterial activities under ambient illumination that result in cell membrane permeability and disorganization, representing an important opportunity for health-related applications. However, the development of antibiofouling surfaces incorporating ZnO nanomaterials has remained limited. In this work, we fabricate superhydrophobic surfaces based on ZnO nanopillars. Water droplets on these superhydrophobic surfaces exhibit small contact angle hysteresis (within 2-3°) and a minimal tilting angle of 1°. Further, falling droplets bounce off when impacting the superhydrophobic ZnO surfaces with a range of Weber numbers (8-46), demonstrating that the surface facilitates a robust Cassie-Baxter wetting state. In addition, the antibiofouling efficacy of the surfaces has been established against model pathogenic Gram-positive bacteria Staphylococcus aureus (S. aureus) and Gram-negative bacteria Escherichia coli (E. coli). No viable colonies of E. coli were recoverable on the superhydrophobic surfaces of ZnO nanopillars incubated with cultured bacterial solutions for 18 h. Further, our tests demonstrate a substantial reduction in the quantity of S. aureus that attached to the superhydrophobic ZnO nanopillars. Thus, the superhydrophobic ZnO surfaces offer a viable design of antibiofouling materials that do not require additional UV illumination or antimicrobial agents.

Seeking shade equity: Tree canopy coverage in public schools in Austin, TX.

BACKGROUND/OBJECTIVES: Tree canopies have dermatologic and environmental benefits, especially on school campuses. However, inequities likely exist, and tree planting initiatives may further exacerbate disparities. We sought to identify any relationship between tree canopy shade on public school campuses in Austin, TX and the socioeconomic makeup of the student population, as well as whether current initiatives appropriately address any inequities. METHODS: In this cross-sectional study, we used ArcGIS, a publicly available geographic information system (GIS), to calculate the percentage of tree canopy on campuses within the Austin Independent School District (AISD) for the years 2006 and 2022. We compared this with the percentage of students eligible for free and reduced meals (FRM) at each school. The percentages of FRM-eligible students were also compared for "low priority" versus "high priority" neighborhoods, as assigned by Austin's Tree Priority Map. RESULTS: Among 112 schools analyzed, schools with minority FRM-eligible students had significantly more tree canopy compared to schools with majority FRM-eligible students (19.9% vs. 12.4%, p < .001). When comparing tree priorities, there was a significant difference between the percentage of FRM-eligible students in "low priority" schools compared to "high priority" schools (23.8% vs. 62.2%, p < .001). CONCLUSIONS: Additional work is needed to rectify inequities in tree canopy access for public school students. Designations such as those used in Austin's Tree Priority Map would likely help direct such efforts. We hope this study encourages future research with GIS by both dermatologists and other health care professionals to promote interdisciplinary work with urban planners.

Quantitation of DNA Using the Applied Biosystems Quantifiler® Trio DNA Quantification Kit.

Following the isolation of deoxyribonucleic acid (DNA) from biological samples, the quantitation of amplifiable human DNA is a critical next step in the process of DNA analysis. The Quantifiler® Trio kit provides a simple way to accurately estimate the quantity of human and male DNA with concentrations as low as 5 pg/µL or less. Not only can the Quantifiler® Trio kit determine the quantity of human DNA present, but it can also give an indication of the quality of the sample, which is essential information to have in the decision-making process regarding any downstream testing being done. In this chapter, we describe how to prepare and process quantitation reactions using the Quantifiler® Trio kit. We also provide basic information on how to interpret the results.

Applied Biosystems' GlobalFiler™ PCR Amplification Kit.

The GlobalFiler™ PCR Amplification Kit is one of the most sensitive kits that exist today that makes the PCR amplification of human DNA possible. PCR amplification using this specific kit makes millions of copies of 24 specific target sequences in the DNA, called markers or loci. This kit is a 6-dye, short tandem repeat (STR) multiplex assay kit that has a synthetic mix of primers and single-stranded oligonucleotides that are combined with DNA samples and then subjected to 29 or 30 cycles of denaturing, annealing, and extension, as per laboratory protocol. Methods for instrument operation will vary depending on the thermal cycler instrument model that is used. Nevertheless, the GlobalFiler™ PCR Amplification Kit has proven to be a very useful tool to DNA analysts, amplifying extremely low quantities of DNA, making it possible to detect partial, if not full, genetic profiles from a wide range of sample types. This chapter discusses the typical preparation and PCR amplification of human forensic DNA samples, using the GlobalFiler™ PCR Amplification Kit.

Acute resveratrol exposure does not impact hemodynamics of the fetal sheep.

Babies born growth restricted are at an increased risk of both poor short-and long-term outcomes. Current interventions to improve fetal growth are ineffective and do not lower the lifetime risk of poor health status. Maternal resveratrol (RSV) treatment increases uterine artery blood flow, fetal oxygenation, and fetal weight. However, studies suggest that diets high in polyphenols such as RSV may impair fetal hemodynamics. We aimed to characterize the effect of RSV on fetal hemodynamics to further assess its safety as an intervention strategy. Pregnant ewes underwent magnetic resonance imaging (MRI) scans to measure blood flow and oxygenation within the fetal circulation using phase contrast-MRI and T2 oximetry. Blood flow and oxygenation measures were performed in a basal state and then repeated while the fetus was exposed to RSV. Fetal blood pressure and heart rate were not different between states. RSV did not impact fetal oxygen delivery (DO2 ) or consumption (VO2 ). Blood flow and oxygen delivery throughout the major vessels of the fetal circulation were not different between basal and RSV states. As such, acute exposure of the fetus to RSV does not directly impact fetal hemodynamics. This strengthens the rationale for the use of RSV as an intervention strategy against fetal growth restriction.

The indelible marks on dermatology: Impacts of COVID-19 on dermatology residency Match using the Texas STAR database.

With changes to interview format and away rotations, the COVID-19 pandemic has reshaped the residency application process. In this retrospective cohort study of data from the nationwide Texas Seeking Transparency in Applications to Residency (STAR) survey, we sought to understand how the pandemic has affected applicants in the 2021 dermatology Match. We compared applicants in the post-COVID-19 Match year (2021) with those in pre-COVID-19 Match years (2018-2020) regarding match rates, interview costs, residency geographic connections, and number of interviews attended. A total of 439 dermatology applicants who completed the Texas STAR survey were included. There was no difference in percentage of applicants with a geographic connection to their matched program (43.88% vs 47.20%). Compared with prior cycles, applicants in the 2021 Match had a higher percentage of interview offers (96% vs 90%, P < .0001), and more applicants attended 16 or more interviews (P = .0489). Applicants in the 2021 Match reported an average savings of $5,000 compared with prior cycles. Virtual interviews offer savings for applicants but may encourage interview hoarding. Though applicants did not perform away rotations, there was no increase in geographic connection for matched applicants. Stakeholders should consider these data when evaluating the pros and cons of virtual interviewing postpandemic.

MRI Characterization of Blood Flow and Oxygen Delivery in the Fetal Sheep whilst Exposed to Sildenafil Citrate.

INTRODUCTION: Newborns exposed to sildenafil citrate (SC) in utero have increased rates of persistent pulmonary hypertension. The mechanism behind this has not yet been fully elucidated. We aimed to utilize a combination of clinically relevant MRI techniques to comprehensively characterize the haemodynamics of the fetal sheep whilst under the influence of SC. We hypothesized that these MRI techniques would detect SC-induced increases in pulmonary blood flow and oxygen delivery prior to birth. METHODS: At 116-117 days gestational age (term, 150 days), pregnant Merino ewes (n = 9) underwent fetal catheterization surgery. MRI scans were performed during a basal state and then repeated during a constant umbilical vein infusion of SC to measure blood flow and oxygenation within the major vessels of the fetal circulation using phase-contrast-MRI and T2 oximetry. RESULTS: Right and left ventricular cardiac outputs were not different between states. Pulmonary blood flow increased during the SC state resulting in elevated pulmonary oxygen delivery. Right to left heart shunting through the foramen ovale was reduced without reducing cerebral oxygen delivery. CONCLUSION: SC induces alterations to pulmonary haemodynamics in utero; a characteristic that if maintained may underlie or act as a precursor towards the elevated rates of poor pulmonary outcomes after birth. These MRI techniques are the first to comprehensively characterize sildenafil's direct impact on the pulmonary vasculature and its indirect detriment to the flow of oxygen-rich blood through the foramen ovale.

Immunogenicity of BNT162b2 COVID-19 vaccine in New Zealand adults.

BACKGROUND: There is very little known about SARS-CoV-2 vaccine immune responses in New Zealand populations at greatest risk for serious COVID-19 disease. METHODS: This prospective cohort study assessed immunogenicity in BNT162b2 mRNA vaccine recipients in New Zealand without previous COVID-19, with enrichment for Maori, Pacific peoples, older adults ≥ 65 years of age, and those with co-morbidities. Serum samples were analysed at baseline and 28 days after second dose for presence of quantitative anti-S IgG by chemiluminescent microparticle immunoassay and for neutralizing capacity against Wuhan, Beta, Delta, and Omicron BA.1 strains using a surrogate viral neutralisation assay. RESULTS: 285 adults with median age of 52 years were included. 55% were female, 30% were Maori, 28% were Pacific peoples, and 26% were ≥ 65 years of age. Obesity, cardiac and pulmonary disease and diabetes were more common than in the general population. All participants received 2 doses of BNT162b2 vaccine. At 28 days after second vaccination, 99.6% seroconverted to the vaccine, and anti-S IgG and neutralising antibody levels were high across gender and ethnic groups. IgG and neutralising responses declined with age. Lower responses were associated with age ≥ 75 and diabetes, but not BMI. The ability to neutralise the Omicron BA.1 variant in vitro was severely diminished but maintained against other variants of concern. CONCLUSIONS: Vaccine antibody responses to BNT162b2 were generally robust and consistent with international data in this COVID-19 naïve cohort with representation of key populations at risk for COVID-19 morbidity. Subsequent data on response to boosters, durability of responses and cellular immune responses should be assessed with attention to elderly adults and diabetics.

The clinical and functional outcomes of a large naturalistic cohort of young people accessing national early psychosis services.

AIMS: Services for individuals with a first episode of psychosis or at ultra-high risk of psychosis have become a treatment model of choice in mental health care. The longitudinal changes in clinical and functional outcomes as a result of real-world treatment remain under-reported. METHODS: We analysed data from first episode of psychosis and ultra-high risk services delivered across Australian primary youth mental health care services known as headspace between 19 June 2017 and 30 September 2019. Outcome measures were completed and entered into a minimum dataset every 90 days a participant was receiving treatment and included psychiatric symptomatology (Brief Psychiatric Rating Scale and psychological distress, K10) and psychosocial functioning (Social and Occupational Functioning Assessment Scale and My Life Tracker). Linear mixed-effects models were used to evaluate changes in outcome over time. RESULTS: Outcome data from a total of 1252 young people were evaluated (643 first episode of psychosis, 609 ultra-high risk). Of those who entered ultra-high risk services, 11.8% transitioned to first episode of psychosis services. Overall, substantial improvement in clinical (Brief Psychiatric Rating Scale, K10) and functional (Social and Occupational Functioning Assessment Scale, My Life Tracker) outcomes were seen across groups and outcomes. Ultra-high risk patients showed a greater reduction in distress symptoms, while first episode of psychosis patients experienced a greater reduction in positive psychosis symptoms. Although clinical outcomes showed a plateau effect after approximately 3 months of care, improvement in functional outcomes (Social and Occupational Functioning Assessment Scale, My Life Tracker) continued later in treatment. CONCLUSION: These findings support the use of real-time, real-world and low-cost administrative data to rigorously evaluate symptomatic and functional outcomes in early psychosis treatment settings. Findings that functional outcomes improve past the remittance of clinical outcomes also support the functional recovery focus of early psychosis services and remaining high levels of distress suggest the need for ultra-high risk services to extend beyond 6 months of care.

Assessing the validity of the Self-Report Webexec Questionnaire: Self-report vs performance neurocognitive inferences.

The Webexec is a self-reported neuropsychological measure, which previous research suggests is associated with personality and executive functions. Though the Webexec could be useful for brief neuropsychological assessment, there is limited literature examining its validity. The current study's purpose was to determine Webexec's validity and association with mood symptomatology in two Historically Black College or University (HBCU) undergraduate student samples. Study 1 employed a neurocognitive battery for convergent validity testing, while the second study utilized psychological measures to determine the Webexec's association with mood-based symptomatology. Study 1 included 149 participants, with a mean age of 20.08 (SD = 1.75) years. Participants completed a demographic questionnaire, the Webexec, and a neuropsychological battery. The neuropsychological battery measured verbal fluency, visual scanning, and working memory. The Webexec was positively associated with working memory (r = 0.18, p = 0.03), but no other neuropsychological measures. Study 2 utilized an online survey with 799 HBCU participants. Results suggest Webexec was associated with depressive symptomatology (r = 0.41, p = 0.01), anxiety symptomatology (r = 0.39, p = 0.01), and impulsivity (r = 0.21, p = 0.01). Taken together, results from both studies suggest the Webexec is not consistently associated with performance measures of executive function and maybe more consistent with self-reported psychological symptoms.

The susceptibility of the aortic root: porcine aortic rupture testing under cardiopulmonary bypass.

BACKGROUND: In our earlier study on the functional limits of the aneurysmal aortic root we determined the pig root is susceptible to failure at high aortic pressures levels. We established a pig rupture model using cardiopulmonary bypass to determine the most susceptible region of the aortic root under the highest pressures achievable using continuous flow, and what changes occur in these regions on a macroscopic and histological level. This information may help guide clinical management of aortic root and ascending aorta pathology. METHODS: Five pigs underwent 4D flow MRI imaging pre surgery to determine vasopressor induced wall sheer stress and flow parameters. All pigs were then placed on cardiopulmonary bypass (CPB) via median sternotomy, and maximal aortic root and ascending aorta flows were initiated until rupture or failure, to determine the most susceptible region of the aorta. The heart was explanted and analysed histologically to determine if histological changes mirror the macroscopic observations. RESULTS: The magnetic resonance imaging (MRI) aortic flow and wall sheer stress (WSS) increased significantly in all regions of the aorta, and the median maximal pressures obtained during cardiopulmonary bypass was 497 mmHg and median maximal flows was 3.96 L/m. The area of failure in all experiments was the non-coronary cusp of the aortic valve. Collagen and elastin composition (%) was greatest in the proximal regions of the aorta. Collagen I and III showed greatest content in the inner aortic root and ascending aorta regions. CONCLUSIONS: This unique porcine model shows that the aortic root is most susceptible to failure at high continuous aortic pressures, supported histologically by different changes in collagen content and subtypes in the aortic root. With further analysis, this information could guide management of the aortic root in disease.

C4-aldehyde of guaiazulene: synthesis and derivatisation.

Guaiazulene is an alkyl-substituted azulene available from natural sources and is a much lower cost starting material for the synthesis of azulene derivatives than azulene itself. Here we report an approach for the selective functionalisation of guaiazulene which takes advantage of the acidity of the protons on the guaiazulene C4 methyl group. The aldehyde produced by this approach constitutes a building block for the construction of azulenes substituted on the seven-membered ring. Derivatives of this aldehyde synthesised by alkenylation, reduction and condensation are reported, and the halochromic properties of a subset of these derivatives have been studied.

The utility of a fidelity measure to monitor implementation of new early psychosis services across Australia.

AIM: Early psychosis delivery models have proliferated worldwide, but there is limited research into establishing model fidelity. In this context, this article aims to describe the development and implementation of a fidelity tool in a national network of early psychosis services across Australia-the headspace Early Psychosis program. METHODS: Following a detailed consultation process, and based on the Australian Early Psychosis model, an 80-item Early Psychosis Prevention and Intervention Centre Model Integrity Tool (EMIT) was developed along with predefined thresholds for fidelity. The tool was used to assess adherence to the model in six clusters of service sites across Australia. Ratings on the EMIT were informed by interviews with site staff and young people receiving the service, routinely collected data and site policies and procedures. RESULTS: All six clusters of headspace Early Psychosis programs participated in five fidelity assessments across a period of two and a half years. In the initial two visits, the average fidelity score was in the 'low' fidelity range (i.e., <75%). By the fifth fidelity visit, the network average improved to 92.35%, reflecting 'superior' fidelity. CONCLUSIONS: Results of the longitudinal fidelity assessments indicate the successful implementation of the Australian Early Psychosis model across the headspace Early Psychosis program. Utilisation of ongoing fidelity assessments has proved an effective method to improve and maintain adherence to the model.

Does the use of dynamic surgical guidance assist accurate pedicle screw placement in patients with osteoporosis or osteopenia? / O uso do guia cirúrgico dinâmico auxilia a acurácia do posicionamento dos parafusos pediculares em pacientes com osteoporose ou osteopenia? / ¿el uso de guía quirúrgica dinámica ayuda a colocar con precisión los tornillos pediculares en pacientes con osteoporosis u osteopenia?

ABSTRACT Objective To compare the use of a dynamic surgical guide (PediGuard®) and pilot hole preparation, with the use of a probe and the aid of fluoroscopy in osteoporotic or osteopenic patients undergoing pedicular fixation of the thoracic or lumbar spine. Methods One hundred and eight patients were randomized. A pilot hole was prepared with the dynamic surgical guide (PediGuard®), or with a probe with the aid of fluoroscopy. A total of 657 vertebral pedicles (120 thoracic and 180 lumbar) were included in the study. The parameters used for the comparison were: accuracy of the pedicular screw, number of fluoroscopic shots, and change in intraoperative trajectory of the perforation after detecting pedicle wall rupture. Results In the group with use of the dynamic surgical guide, malpositioning of the pedicle screws was observed in 8 (2.6%) patients and intraoperative change of perforation trajectory in 12 (4%) patients, and there were 52 fluoroscopic shots. In the group without use of the dynamic surgical guide (PediGuard®), misplacement of the pedicle screws was observed in 33 (11%) patients and intraoperative change of perforation trajectory in 47 (13.2%) patients, and there were 136 fluoroscopic shots. Conclusion The use of the dynamic surgical guide (PediGuard®) in patients with osteoporosis or osteopenia enabled more accurate placement of pedicular screws, with less change in the intraoperative course of the perforation and less intraoperative radiation. Level of Evidence II; Randomized clinical trial of lesser quality.

RESUMO Objetivo Comparar o uso de um guia cirúrgico dinâmico (PediGuard®) e o preparo de orifício piloto com uma sonda e o auxílio de fluoroscopia em pacientes com osteopenia ou osteoporose submetidos à fixação pedicular da coluna torácica ou lombar. Métodos Cento e oito pacientes foram randomizados. Um orifício piloto foi preparado com o guia cirúrgico dinâmico (PediGuard®) ou com uma sonda com auxílio de fluoroscopia. Foram incluídos no estudo 657 pedículos vertebrais (120 torácicos e 180 lombares). Os parâmetros usados para a comparação foram: acurácia da colocação do parafuso pedicular, número de disparos fluoroscópicos e mudança da trajetória intraoperatória da perfuração depois da detecção de ruptura da parede do pedículo. Resultados No grupo de pacientes em que se usou o guia cirúrgico dinâmico, observou-se mau posicionamento dos parafusos pediculares em oito (2,6%) pacientes e alteração da trajetória intraoperatória da perfuração em 12 (4%) pacientes, com 52 disparos fluoroscópicos. No grupo de pacientes em que o guia cirúrgico dinâmico (PediGuard®) não foi usado o mau posicionamento dos parafusos pediculares foi observado em 33 (11%) pacientes, a mudança intraoperatória da trajetória da perfuração foi vista em 47 (13,2%) pacientes, com 136 disparos fluoroscópicos. Conclusão O uso do guia cirúrgico dinâmico (PediGuard®) em pacientes com osteoporose ou osteopenia permitiu a colocação de parafusos pediculares com maior acurácia, com menor alteração da trajetória intraoperatória da perfuração e menor dose de radiação intraoperatória. Nível de Evidência II; Estudo clínico randomizado de menor qualidade.

RESUMEN Objetivo Comparar el uso de una guía quirúrgica dinámica (PediGuard®) y la preparación del orificio piloto con una sonda y la ayuda de fluoroscopia en pacientes con osteopenia u osteoporosis sometidos a fijación pedicular de la columna torácica o lumbar. Métodos Ciento ocho pacientes fueron asignados aleatoriamente. Se preparó un orificio piloto preparado con la guía quirúrgica dinámica (PediGuard®) o con una sonda con ayuda de fluoroscopia. Se incluyeron en el estudio 657 pedículos vertebrales (120 torácicos y 180 lumbares). Los parámetros utilizados para la comparación fueron: precisión de la colocación del tornillo pedicular, número de disparos del dispositivo de fluoroscopia y cambio en la trayectoria intraoperatoria de la perforación después de la detección de ruptura de la pared del pedículo. Resultados En el grupo de pacientes en el que se utilizó la guía quirúrgica dinámica, se observó mal posicionamiento de los tornillos pediculares en 8 (2,6%) pacientes y cambios de la trayectoria intraoperatoria de la perforación en 12 (4%) pacientes, con 52 disparos del aparato de fluoroscopia. En el grupo de pacientes en los que no se utilizó la guía quirúrgica dinámica (PediGuard®), se observó un mal posicionamiento de los tornillos pediculares en 33 (11%) pacientes, el cambio intraoperatorio de la trayectoria de perforación se observó en 47 (13,2%) pacientes, con 136 disparos fluoroscópicos. Conclusión El uso de la guía quirúrgica dinámica (PediGuard®) en pacientes con osteoporosis u osteopenia permitió la colocación de tornillos pediculares con mayor precisión, menos cambios en la trayectoria intraoperatoria de la perforación y dosis más baja de radiación intraoperatoria. Nivel de Evidencia II; Ensayo clínico aleatorizado de menor calidad.

Systematic Review of Pain in Clinical Practice Guidelines for Management of COPD: A Case for Including Chronic Pain?

Chronic pain is highly prevalent and more common in people with chronic obstructive pulmonary disease (COPD) than people of similar age/sex in the general population. This systematic review aimed to describe how frequently and in which contexts pain is considered in the clinical practice guidelines (CPGs) for the broad management of COPD. Databases (Medline, Scopus, CiNAHL, EMbase, and clinical guideline) and websites were searched to identify current versions of COPD CPGs published in any language since 2006. Data on the frequency, context, and specific recommendations or strategies for the assessment or management of pain were extracted, collated, and reported descriptively. Of the 41 CPGs (English n = 20) reviewed, 16 (39%) did not mention pain. Within the remaining 25 CPGs, pain was mentioned 67 times (ranging from 1 to 10 mentions in a single CPG). The most frequent contexts for mentioning pain were as a potential side effect of specific pharmacotherapies (22 mentions in 13 CPGs), as part of differential diagnosis (14 mentions in 10 CPGs), and end of life or palliative care management (7 mentions in 6 CPGs). In people with COPD, chronic pain is common; adversely impacts quality of life, mood, breathlessness, and participation in activities of daily living; and warrants consideration within CPGs for COPD.

Differentiation of transplanted microencapsulated fetal pancreatic cells.

BACKGROUND: Fetal beta cells are a potential form of cell therapy for type 1 diabetes. To protect transplanted cells from cellular immune attack, microencapsulation using barium alginate can be employed. Whether microencapsulated fetal pancreatic cells will differentiate as occurs with nonencapsulated fetal pancreatic cells is presently unknown. It is suggested that such differentiation would occur in encapsulated cells, similar to previous experiments conducted using encapsulated embryonic stem cells. METHODS: Streptozotocin-induced diabetic severe combined immunodeficient mice were transplanted with 5,000 to 38,000 fetal pig islet-like cell clusters (ICCs) within barium alginate microcapsules of diameter 300, 600, or 1000 microm. Viability, insulin secretion, and content of encapsulated cells were measured prior to transplantation. Blood glucose levels (BGL) were measured twice weekly and porcine C-peptide monthly. Encapsulated cells were recovered from mice at 6 months posttransplantation for analysis. RESULTS: Encapsulated cells became glucose responsive and normalized BGL within 13 to 68 days posttransplantation, with 5,000 to 10,000 ICCs required. Microcapsule diameter did not affect the time required to achieve normoglycemia. BGL remained normal for the 6-month duration of the experiments. After removal of grafts at 25 weeks posttransplantation, glucose stimulated insulin secretion of the explants was enhanced 96-fold, insulin content was enhanced 34-fold, and the percentage of insulin and glucagon positive cells increased 10-fold and threefold, respectively, from the time of transplantation. CONCLUSIONS: This study demonstrates that fetal pancreatic cells differentiate and function normally when placed within barium alginate microcapsules and transplanted.

Transplantation of 3D scaffolds seeded with human embryonic stem cells: biological features of surrogate tissue and teratoma-forming potential.

AIM: To generate complex surrogate tissue by transplanting 3D scaffolds seeded with human embryonic stem cells (hESCs) between the liver lobules of severe combined immunodeficient (SCID) mice and to assess the teratoma-forming potential. MATERIALS & METHODS: 3D poly-(lactic-co-glycolic acid) (PLGA) scaffolds coated with laminin were seeded with hESCs and then transplanted between the liver lobules of SCID mice. After a period of in vivo differentiation, the scaffolds were retrieved and analyzed using reverse transcription polymerase chain reaction, immunofluorescent staining and scanning electron microscopy. RESULTS: A proportion of the hESCs within the scaffolds differentiated into cells that produced proteins characteristic of specific tissues, including endoderm and pancreatic markers glucogon-like peptide-1 receptor, islet amyloid polypeptide and Insulin. Markers of hepatic and neuronal lineages were also investigated. Major matrix proteins abundant in multiple tissue types, including collagen I, laminin and collagen IV, were found to be profuse within the scaffold pores. Transplantation of the seeded scaffolds between liver lobules also resulted in extensive vascularization both from host blood vessel incursion and the differentiation of hESCs into endothelial progenitor cells. An investigation of teratoma-forming potential demonstrated that transplantation of 3D scaffolds seeded with hESCs will, under certain conditions, lead to the growth of teratomas. DISCUSSION: Transplantation of 3D scaffolds seeded with hESCs between liver lobules resulted in the development of surrogate tissue containing cells that produced proteins representing the pancreatic, hepatic and neuronal lineages, the assembly of an extracellular matrix structure and the formation of a vasculature. hESCs seeded within 3D scaffolds and transplanted into SCID mice were capable of forming teratomas. However, the formation and progression of teratoma growth is shown to be dependant on both the site of transplantation and the treatment of cells prior to transplantation.

Differentiation of encapsulated embryonic stem cells after transplantation.

BACKGROUND: Embryonic stem cells (ESC) when transplanted into recipients with different major histocompatibility antigens may be rejected, especially as cells differentiate and expression of these antigens increases. One method to prevent rejection is to place the developing ESC in microcapsules. It is currently unknown what effect encapsulation has on the ability of ESC to differentiate. METHODS: Human ESC (hESC; hES03 line) and mouse ESC (mESC; R1 line) were encapsulated in 2.2% barium alginate and transplanted intraperitoneally in SCID and BALB/c mice respectively. Cell morphology, viability, and gene characterization were assessed after retrieving the capsules up to four weeks from SCID mice and three months from BALB/c mice. RESULTS: Encapsulation prevented hESC and mESC from forming teratomas up to four weeks and three months, respectively. mESC but not hESC formed aggregates within the capsules, which remained free of fibrosis. Some but not all the transplanted encapsulated hESC differentiated towards all three lineages, but more so towards an endodermal lineage as shown by increased expression of alpha fetoprotein. This was similar to what occurred when encapsulated and non-encapsulated hESC were cultured in vitro for two weeks. In contrast to the hESC, transplanted encapsulated mESC differentiated mostly towards an ectodermal lineage as shown by increased expression of nestin and glial fibrillary acidic protein. In vitro, encapsulated and nonencapsulated mESC also began to differentiate, but not down any specific lineage. CONCLUSIONS: Encapsulated ESC do differentiate, although along multiple pathways, both when transplanted and maintained in culture, just as nonencapsulated ESC do when removed from their feeder layer.