Impaired motor inhibition during perceptual inhibition in older, but not younger adults: a psychophysiological study.

The prefrontal cortex (PFC) governs the ability to rapidly cancel planned movements when no longer appropriate (motor inhibition) and ignore distracting stimuli (perceptual inhibition). It is unclear to what extent these processes interact, and how they are impacted by age. The interplay between perceptual and motor inhibition was investigated using a Flanker Task, a Stop Signal Task and a combined Stop Signal Flanker Task in healthy young (n = 33, Mean = 24 years) and older adults (n = 32, Mean = 71 years). PFC activity was measured with functional near-infrared spectroscopy (fNIRS), while electromyography (EMG) measured muscle activity in the fingers used to respond to the visual cues. Perceptual inhibition (the degree to which incongruent flankers slowed response time to a central cue) and motor inhibition (the speed of cancellation of EMG activation following stop cues) independently declined with age. When both processes were engaged together, PFC activity increased for both age groups, however only older adults exhibited slower motor inhibition. The results indicate that cortical upregulation was sufficient to compensate for the increased task demands in younger but not older adults, suggesting potential resource sharing and neural limitations particularly in older adults.

Impact of multidisciplinary team meetings on the management of patients with breast cancer in a large private healthcare facility.

AIMS: Multidisciplinary meetings (MDMs) play a crucial role in decision-making in breast cancer patient care. This study aimed to firstly assess the impact of breast cancer MDMs in decision-making for breast cancer patients and secondly to determine the concordance between MDM recommendations and implementation of clinical practice. METHODS: Patient cases to be presented at the weekly breast cancer MDMs were identified and prospectively enrolled. Management plans were predicted by the treating surgeon with the pre-MDM management plans then compared to MDM recommendations. Changes in decision-making were assessed in the following domains: further surgery, systemic therapy (endocrine, chemotherapy or targeted), radiotherapy, enrolment in a clinical trial, further investigations, and referral to other specialists or services. Patient records were subsequently reviewed at 3 months post-MDM to assess the rate of implementation of MDM recommendations and any reasons for discordance. RESULTS: Out of 50 cases, 66% (CI 53-79%; p < .005) experienced a change in management plan as a result of MDM discussion, with a total of 66 episodes of recorded change per decision-making domain affecting the following: further surgery (7.6%), endocrine therapy (4.5%), chemotherapy (19.7%), targeted therapy (4.5%), radiotherapy (18.2%), enrolment for a clinical trial (12.1%), additional investigations (22.7%), and further referrals (10.6%). MDM recommendations were implemented in 83.7% of cases. CONCLUSION: The breast cancer MDMs were found to substantially impact on the management plans for breast cancer patients, with 83.7% of MDM recommendations being implemented into clinical practice. This study reinforces the importance of MDMs in the management of these patients, as well as highlighting the need for further investigating and addressing the potential barriers to the implementation of MDM recommendations.

Patterns of breast reconstruction and the influence of a surgical multidisciplinary clinic.

BACKGROUND: Of the 40% of breast cancer patients who have a mastectomy as part of their surgical treatment, only approximately 29% have a breast reconstruction. In 2016, Alfred Health established a multidisciplinary surgical clinic with breast and plastic surgeons, aiming to improve interdisciplinary collaboration. This study aimed to assess the provision of breast reconstruction at an Australian tertiary public hospital and examine whether the multidisciplinary surgical clinic have improved our reconstructive service provision. METHODS: A retrospective cohort study of patients who underwent mastectomy at Alfred Health between October 2011 and September 2021 was conducted. Patients were divided into before and after groups, treated during the 5-year period before and after establishing the multidisciplinary clinic respectively. Demographic data, operative details, histopathology, and treatments were compared. RESULTS: Over the 10-year period, 423 mastectomies were performed for 351 patients. Of those, 153 patients underwent breast reconstruction, providing an overall reconstruction rate of 43.6%. There was a statistically significant increase in the breast reconstruction rate from 36.5% before to 53.4% after the creation of the multidisciplinary surgical clinic. Patient factors such as age and tumour receptor status did not differ significantly between the groups. CONCLUSION: The establishment of a surgical multidisciplinary clinic has led to a statistically significant increase in the rate of breast reconstruction from 36.5% to 53.4%, leading to improved healthcare provision for our patients. Factors identified to be associated with increased uptake in the reconstruction service include younger age and node negative disease.

Palliative Care Utilization in Burn Patients.

Background: Burn injuries are a common cause for hospitalization, and severe burns have an increased risk of death in patients with advanced age, inhalational injury, comorbid conditions. Very little is known about the utilization of palliative care consultation in burn patients. Objective: The aim of this study was to evaluate the factors influencing the utilization of inpatient palliative care consultation for patients with severe burn injuries. Methods: This was a retrospective chart review study at a single burn center. Results: Seventeen out of 191 patients (8.9%) received a palliative care consultation with the average time for consultation of 10.3 days. Factors that appear to impact consultation were age, presence of inhalational injury, and multiple comorbid conditions. Conclusion: Inpatient palliative care consultation was underutilized in patients with severe burn injurie. Further research into the outcomes of palliative care consultation could help further support the utility of early involvement in burn patients.

A high-resolution multi-shell 3T diffusion magnetic resonance imaging dataset as part of the Amsterdam Ultra-high field adult lifespan database (AHEAD).

In order to further our understanding of brain function and the underlying networks, more advanced diffusion weighted magnetic resonance imaging (DWI MRI) data are essential. Here we present freely available high-resolution multi-shell multi-directional 3 Tesla (T) DWI MRI data as part of the 'Amsterdam Ultra-high field adult lifespan database' (AHEAD). The 3T DWI AHEAD dataset include 1.28mm isotropic whole brain DWI data of 49 healthy adult participants between 18 and 90 years old. The acquired data include DWIs at three non-zero b-values (48 directions, b-value 700 s/mm2; 56 directions, b-value 1000 s/mm2; 64 directions, b-value 1600 s/mm2) including a total of twelve volumes with a b-value of 0 s/mm2 (b0 volumes). In addition, eight b0 volumes with a reversed phase encoding direction were acquired to correct for distortions. To facilitate future use, the DWI data have been denoised, corrected for eddy currents, susceptibility-induced off-resonance field distortions, bias fields, and are skull stripped.

Effect of Sunscreen Application on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial.

Importance: A prior pilot study demonstrated the systemic absorption of 4 sunscreen active ingredients; additional studies are needed to determine the systemic absorption of additional active ingredients and how quickly systemic exposure exceeds 0.5 ng/mL as recommended by the US Food and Drug Administration (FDA). Objective: To assess the systemic absorption and pharmacokinetics of the 6 active ingredients (avobenzone, oxybenzone, octocrylene, homosalate, octisalate, and octinoxate) in 4 sunscreen products under single- and maximal-use conditions. Design, Setting, and Participants: Randomized clinical trial at a clinical pharmacology unit (West Bend, Wisconsin) was conducted in 48 healthy participants. The study was conducted between January and February 2019. Interventions: Participants were randomized to 1 of 4 sunscreen products, formulated as lotion (n = 12), aerosol spray (n = 12), nonaerosol spray (n = 12), and pump spray (n = 12). Sunscreen product was applied at 2 mg/cm2 to 75% of body surface area at 0 hours on day 1 and 4 times on day 2 through day 4 at 2-hour intervals, and 34 blood samples were collected over 21 days from each participant. Main Outcomes and Measures: The primary outcome was the maximum plasma concentration of avobenzone over days 1 through 21. Secondary outcomes were the maximum plasma concentrations of oxybenzone, octocrylene, homosalate, octisalate, and octinoxate over days 1 through 21. Results: Among 48 randomized participants (mean [SD] age, 38.7 [13.2] years; 24 women [50%]; 23 white [48%], 23 African American [48%], 1 Asian [2%], and 1 of unknown race/ethnicity [2%]), 44 (92%) completed the trial. Geometric mean maximum plasma concentrations of all 6 active ingredients were greater than 0.5 ng/mL, and this threshold was surpassed on day 1 after a single application for all active ingredients. For avobenzone, the overall maximum plasma concentrations were 7.1 ng/mL (coefficient of variation [CV], 73.9%) for lotion, 3.5 ng/mL (CV, 70.9%) for aerosol spray, 3.5 ng/mL (CV, 73.0%) for nonaerosol spray, and 3.3 ng/mL (CV, 47.8%) for pump spray. For oxybenzone, the concentrations were 258.1 ng/mL (CV, 53.0%) for lotion and 180.1 ng/mL (CV, 57.3%) for aerosol spray. For octocrylene, the concentrations were 7.8 ng/mL (CV, 87.1%) for lotion, 6.6 ng/mL (CV, 78.1%) for aerosol spray, and 6.6 ng/mL (CV, 103.9%) for nonaerosol spray. For homosalate, concentrations were 23.1 ng/mL (CV, 68.0%) for aerosol spray, 17.9 ng/mL (CV, 61.7%) for nonaerosol spray, and 13.9 ng/mL (CV, 70.2%) for pump spray. For octisalate, concentrations were 5.1 ng/mL (CV, 81.6%) for aerosol spray, 5.8 ng/mL (CV, 77.4%) for nonaerosol spray, and 4.6 ng/mL (CV, 97.6%) for pump spray. For octinoxate, concentrations were 7.9 ng/mL (CV, 86.5%) for nonaerosol spray and 5.2 ng/mL (CV, 68.2%) for pump spray. The most common adverse event was rash, which developed in 14 participants. Conclusions and Relevance: In this study conducted in a clinical pharmacology unit and examining sunscreen application among healthy participants, all 6 of the tested active ingredients administered in 4 different sunscreen formulations were systemically absorbed and had plasma concentrations that surpassed the FDA threshold for potentially waiving some of the additional safety studies for sunscreens. These findings do not indicate that individuals should refrain from the use of sunscreen. Trial Registration: ClinicalTrials.gov Identifier: NCT03582215.

Undergraduate, Nonmedical Students can Pass the FLS Manual Skills Exam With Minimal Practice.

OBJECTIVES: The primary objective of this study is to investigate whether undergraduate, nonmedical students could pass the FLS Manual Skills Exam with minimal practice. The secondary objective is to examine ACGME case log data from graduating chief residents over the past 18 years to examine how laparoscopic experience has evolved over that time period. DESIGN: Undergraduate, nonmedical students received training and unlimited practice time before being tested on each task of the FLS Manual Skills Exam. Each task was timed and scored using the MISTELS system. ACGME case log data from graduating chief residents over the past 18 years was obtained. SETTING: The setting is SimPortal, the simulation center associated with the University of Minnesota Medical School. PARTICIPANTS: The participants are 25 undergraduate, nonmedical students from the University of Minnesota. Participants were recruited on campus. RESULTS: Twenty-three out of 25 (92%) undergraduate, nonmedical students successfully completed one attempt for each task of the FLS Manual Skills Exam and 21 out of 25 (84%) completed both attempts. The average total practice time was 39 minutes. Over the past 18 years, the average number of laparoscopic cases completed by a graduating chief increased from 142 to 275 cases (93% increase). Additionally, the average number of cases of the top 5 most common laparoscopic operations increased from 25% to over 400%. CONCLUSIONS: Undergraduate, nonmedical students can pass the FLS Manual Skills Exam with minimal practice. Additionally, general surgery residents and medical students continue to gain more laparoscopic experience throughout medical training as laparoscopic surgery is utilized for more operations. The FLS Manual Skills Exam should be re-examined to determine its utility as a high-stakes exam.

Effect of Sunscreen Application Under Maximal Use Conditions on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial.

Importance: The US Food and Drug Administration (FDA) has provided guidance that sunscreen active ingredients with systemic absorption greater than 0.5 ng/mL or with safety concerns should undergo nonclinical toxicology assessment including systemic carcinogenicity and additional developmental and reproductive studies. Objective: To determine whether the active ingredients (avobenzone, oxybenzone, octocrylene, and ecamsule) of 4 commercially available sunscreens are absorbed into systemic circulation. Design, Setting, and Participants: Randomized clinical trial conducted at a phase 1 clinical pharmacology unit in the United States and enrolling 24 healthy volunteers. Enrollment started in July 2018 and ended in August 2018. Interventions: Participants were randomized to 1 of 4 sunscreens: spray 1 (n = 6 participants), spray 2 (n = 6), a lotion (n = 6), and a cream (n = 6). Two milligrams of sunscreen per 1 cm2 was applied to 75% of body surface area 4 times per day for 4 days, and 30 blood samples were collected over 7 days from each participant. Main Outcomes and Measures: The primary outcome was the maximum plasma concentration of avobenzone. Secondary outcomes were the maximum plasma concentrations of oxybenzone, octocrylene, and ecamsule. Results: Among 24 participants randomized (mean age, 35.5 [SD, 1.5] years; 12 (50%] women; 14 [58%] black or African American; 14 [58%]), 23 (96%) completed the trial. For avobenzone, geometric mean maximum plasma concentrations were 4.0 ng/mL (coefficient of variation, 6.9%) for spray 1; 3.4 ng/mL (coefficient of variation, 77.3%) for spray 2; 4.3 ng/mL (coefficient of variation, 46.1%) for lotion; and 1.8 ng/mL (coefficient of variation, 32.1%). For oxybenzone, the corresponding values were 209.6 ng/mL (66.8%) for spray 1, 194.9 ng/mL (52.4%) for spray 2, and 169.3 ng/mL (44.5%) for lotion; for octocrylene, 2.9 ng/mL (102%) for spray 1, 7.8 ng/mL (113.3%) for spray 2, 5.7 ng/mL (66.3%) for lotion, and 5.7 ng/mL (47.1%) for cream; and for ecamsule, 1.5 ng/mL (166.1%) for cream. Systemic concentrations greater than 0.5 ng/mL were reached for all 4 products after 4 applications on day 1. The most common adverse event was rash, which developed in 1 participant with each sunscreen. Conclusions and Relevance: In this preliminary study involving healthy volunteers, application of 4 commercially available sunscreens under maximal use conditions resulted in plasma concentrations that exceeded the threshold established by the FDA for potentially waiving some nonclinical toxicology studies for sunscreens. The systemic absorption of sunscreen ingredients supports the need for further studies to determine the clinical significance of these findings. These results do not indicate that individuals should refrain from the use of sunscreen. Trial Registration: ClinicalTrials.gov Identifier: NCT03582215.

Stenting the Upper/Cervical Oesophagus with a Proximal Deployment Cervical Oesophageal Stent: Technique and Outcomes.

INTRODUCTION: Proximal oesophageal stent deployment continues to provide challenges due to the proximity of the upper oesophageal sphincter and the associated subsequent complications such as globus sensation and stent migration. Patients with cervical oesophageal cancer have previously had limited stenting options available to them with a paucity of the literature describing the radiological technique for successfully placing these high-risk stents. In this paper, we present our experience using the Taewoong Niti-S CERVICAL Oesophageal Stent. MATERIALS AND METHODS: We describe our method for stent deployment highlighting the importance of pre-procedural planning in ensuring an adequate proximal landing zone for the short proximal flare of the stent. Furthermore, we outline how we have adapted our placement technique to incorporate a routine pre-dilatation stage which has optimised retrieval of the proximal to distal deployment system. RESULTS: We have placed eight cervical oesophageal stents within our institution. Contrast swallows in all the patients following stent deployment have demonstrated free flow of contrast to the stomach with all patients reporting symptomatic relief and no foreign body/globus sensation. There has been one episode of stent migration but no incidence of oesophageal perforation or haemorrhage. DISCUSSION: Evolution of stenting technique and the properties of the stents themselves are improving accuracy of stent placement in relation to the important landmark of the upper oesophageal sphincter. CONCLUSION: Stenting of cervical oesophageal malignancy has proved successful in our institution and provided symptom relief for a subset of palliative patients who were previously unable to benefit from oesophageal stenting.

Assessment of Multi-Ion Channel Block in a Phase I Randomized Study Design: Results of the CiPA Phase I ECG Biomarker Validation Study.

Balanced multi-ion channel-blocking drugs have low torsade risk because they block inward currents. The Comprehensive In Vitro Proarrhythmia Assay (CiPA) initiative proposes to use an in silico cardiomyocyte model to determine the presence of balanced block, and absence of heart rate corrected J-Tpeak (J-Tpeak c) prolongation would be expected for balanced blockers. This study included three balanced blockers in a 10-subject-per-drug parallel design; lopinavir/ritonavir and verapamil met the primary end point of ΔΔJ-Tpeak c upper bound < 10 ms, whereas ranolazine did not (upper bounds of 8.8, 6.1, and 12.0 ms, respectively). Chloroquine, a predominant blocker of the potassium channel encoded by the ether-à-go-go related gene (hERG), prolonged ΔΔQTc and ΔΔJ-Tpeak c by ≥ 10 ms. In a separate crossover design, diltiazem (calcium block) did not shorten dofetilide-induced ΔQTc prolongation, but shortened ΔJ-Tpeak c and prolonged ΔTpeak -Tend . Absence of J-Tpeak c prolongation seems consistent with balanced block; however, small sample size (10 subjects) may be insufficient to characterize concentration-response in some cases.

Using transcranial magnetic stimulation to investigate the neural mechanisms of inhibitory control.

Many everyday actions require inhibitory control. The success of these actions depends on the availability of prior information regarding stopping demands. Using transcranial magnetic stimulation (TMS), Cirillo and colleagues (Cirillo J, Cowie MJ, MacDonald HJ, Byblow WD. J Neurophysiol 119: 877-886, 2018) provide novel neurophysiological evidence for distinct roles of intracortical inhibitory mechanisms underlying inhibitory control. Other, nonexclusive mechanisms such as disfacilitation of excitatory pathways and interhemispheric inhibition may also contribute to inhibitory control. Accordingly, diverse TMS protocols are a valuable assessment tool to investigate these mechanisms.

Distinct modulation of interhemispheric inhibitory mechanisms during movement preparation reveals the influence of cognition on action control.

When selecting actions based on visual warning stimuli (WS), corticospinal excitability (CSE) is initially suppressed, consistent with a neural mechanism to prevent premature release of the competing responses. Despite being implicated in between-hand movement selection and preparation, the role that interhemispheric inhibition (IHI) may play in this 'impulse control' mechanism is not known. Participants performed a warned, between-hand, choice reaction time (RT) task in which the informativeness of the WS (with regards to which hand would be required to respond) was manipulated. Transcranial magnetic stimulation (TMS) assessed CSE of the right primary motor cortex (M1) and IHI from left to right M1 with 10 (IHI10) and 40 (IHI40) msec interstimulus intervals during movement selection and preparation. Consistent with impulse control, CSE was initially suppressed prior to both left and right hand actions, irrespective of WS informativeness. Subsequent CSE increases occurred in the responding hand which were larger, and occurred earlier, following an informative WS. Importantly, these increases strongly predicted response times. In contrast to the generic CSE suppression, an informative WS permitted a hand-specific release of IHI10 in the responding hand, whereas IHI40 was released in both hands. As releases of IHI cannot explain a simultaneous suppression of CSE, this suggests several distinct movement preparation mechanisms are at play with IHI modulation occurring independently from impulse control. Notably, the findings support the notion that IHI10 and IHI40 between contralateral motor regions are mediated by discrete transcallosal pathways, and are differently modulated by specific motor and cognitive attributes of a rapid choice task.

ADAM17 in tumor associated leukocytes regulates inflammatory mediators and promotes mammary tumor formation.

The presence of inflammatory cells within the tumor microenvironment has been tightly linked to mammary tumor formation and progression. Specifically, interactions between tumor cells and infiltrating macrophages can contribute to the generation of a pro-tumorigenic microenvironment. Understanding the complex mechanisms that drive tumor cell-macrophage cross-talk will ultimately lead to the development of approaches to prevent or treat early stage breast cancers. As described here, we demonstrate that the cell surface protease a disintegrin and metalloproteinase 17 (ADAM17) is expressed by macrophages in mammary tumors and contributes to regulating the expression of pro-inflammatory mediators, including inflammatory cytokines and the inflammatory mediator cyclooxygenase-2 (Cox-2). Furthermore, we demonstrate that ADAM17 is expressed on leukocytes, including macrophages, within polyoma middle T (PyMT)-derived mammary tumors. Genetic deletion of ADAM17 in leukocytes resulted in decreased onset of mammary tumor growth, which was associated with reduced expression of the Cox-2 within the tumor. These findings demonstrate that ADAM17 regulates key inflammatory mediators in macrophages and that leukocyte-specific ADAM17 is an important promoter of mammary tumor initiation. Understanding the mechanisms associated with early stage tumorigenesis has implications for the development of preventive and/or treatment strategies for early stage breast cancers.

Epiregulin contributes to breast tumorigenesis through regulating matrix metalloproteinase 1 and promoting cell survival.

BACKGROUND: The epidermal growth factor (EGF) family of ligands has been implicated in promoting breast cancer initiation, growth and progression. The contributions of EGF family ligands and their receptors to breast cancer are complex, and the specific mechanisms through which different ligands regulate breast tumor initiation and growth are not well-defined. These studies focus on the EGF family member epiregulin (EREG) as a mediator of early stage breast tumorigenesis. METHODS: EREG expression levels were assessed in both cell lines and human samples of ductal carcinoma in situ (DCIS) using quantitative RT-PCR, ELISA and immunohistochemistry. Gene knock-down approaches using shRNA-based strategies were used to determine the requirement of EREG for growth of MCF10DCIS cells in vivo, and for identifying mechanisms through which EREG promotes tumor cell survival. Experiments were performed using a combination of two-dimensional culture, three-dimensional culture and tumor growth in vivo. RESULTS: In comparison with other EGF family members, EREG was induced in MCF10DCIS cells compared with MCF10A and MCF10AT cells and its expression was partially regulated by fibroblast growth factor receptor (FGFR) activity. Reduced EREG expression in MCF10DCIS cells led to decreased tumor growth in vivo, which was associated with reduced cell survival. Furthermore, treatment of MCF10A cells with exogenous EREG enhanced cell survival both in three-dimensional culture and in response to chemotherapeutic agents. Examination of EREG-induced signaling pathways demonstrated that EREG promoted survival of MCF10A cells through regulating expression of matrix metalloproteinase-1 (MMP-1). To determine the relevance of these findings in human tumors, samples of DCIS were analyzed for EREG and MMP-1 expression. EREG was induced in DCIS lesions compared to normal breast epithelium, and EREG and MMP-1 were correlated in a subset of DCIS samples. CONCLUSIONS: Together, these studies lead to identification of a novel pathway involving EREG and MMP-1 that contributes to the formation of early stage breast cancer. Understanding these complex pathways could ultimately lead to the development of novel biomarkers of neoplastic progression and/or new therapeutic strategies for patients with early stage cancer.

Assessment of cell line models of primary human cells by Raman spectral phenotyping.

Researchers have previously questioned the suitability of cell lines as models for primary cells. In this study, we used Raman microspectroscopy to characterize live A549 cells from a unique molecular biochemical perspective to shed light on their suitability as a model for primary human pulmonary alveolar type II (ATII) cells. We also investigated a recently developed transduced type I (TT1) cell line as a model for alveolar type I (ATI) cells. Single-cell Raman spectra provide unique biomolecular fingerprints that can be used to characterize cellular phenotypes. A multivariate statistical analysis of Raman spectra indicated that the spectra of A549 and TT1 cells are characterized by significantly lower phospholipid content compared to ATII and ATI spectra because their cytoplasm contains fewer surfactant lamellar bodies. Furthermore, we found that A549 spectra are statistically more similar to ATI spectra than to ATII spectra. The spectral variation permitted phenotypic classification of cells based on Raman spectral signatures with >99% accuracy. These results suggest that A549 cells are not a good model for ATII cells, but TT1 cells do provide a reasonable model for ATI cells. The findings have far-reaching implications for the assessment of cell lines as suitable primary cellular models in live cultures.

Expression of blood dendritic cell antigens (BDCAs) by CD1a+ human pulmonary cells.

BACKGROUND: Myeloid and plasmacytoid dendritic cell (DC) subsets have been recently identified in the human lung based on their differential expression of Blood DC Antigens 1-3 (BDCAs). We investigated the expression of these antigens by isolated human pulmonary CD1a(+) DCs, namely Langerhan's cells. METHODS: Using an in vitro cell culture system we successfully isolated a population of relatively pure (>70%) CD1a(+) cells from human lung tissue (n=5 subject samples) and stained these with antibodies against the myeloid DC markers BDCA1 (CD1c) and BDCA3 (CD303), the plasmacytoid DC marker BDCA2 (CD141), the Langerhan's cell marker Langerin and the maturation marker CD83. RESULTS: Among different subject samples, the isolated CD1a(+) cells showed variable expression of Langerin, BDCAs and CD83. Interestingly, in two subject samples, which contained >70% CD83(+) mature CD1a(+) cells, >50% of the cells were positive for all of the BDCAs. CONCLUSIONS: We conclude that isolated pulmonary CD1a(+) DCs in vitro have the capacity to express both myeloid and plasmacytoid BDCA markers and that rather than subset restriction in pulmonary DCs, a significant degree of flexibility/plasticity can be induced, albeit experimentally.

Hemithyroidectomy: a heuristics perspective.

Heuristics describe the multiple small steps required for successful surgery, which are often taken for granted, enabling key manoeuvres, their correct order and their timely performance. Successful hemithyroidectomy is dependent on correct siting of the incision; tension to allow elevation of sub-platysmal flaps without damaging anterior jugular veins; strap muscle division with preservation of the ansa cervicalis; recognition of the importance of the sub-sternothyroid plane; superior mobility of the thyroid lobe, involving freeing the superior strap muscle layer and dissection of the pyramidal lobe; division of the isthmus to assist anteromedial mobility; dissection of the lateral thyroid space to free the posterior 'v' lip of the superior pole; medial to lateral dissection of the avascular cricothyroid space with preservation of the external laryngeal nerve, prior to ligation of the superior thyroid vessels; anteromedial rotation of the thyroid lobe with elevation of any retrosternal component; capsular dissection of the inferior pole with preservation of vascularity of the inferior parathyroid gland; dissection of the thyroid lobe off the recurrent laryngeal nerve, especially above the inferior thyroid artery in the region of greatest risk to the nerve, the region of the ligament of Berry; preservation of a vascularized superior parathyroid gland; capsular dissection, creating windows between vessels enabling their precise control, thereby minimizing haemorrhage. This paper aims to emphasize these heuristic components of thyroidectomy.

Spectral monitoring of surfactant clearance during alveolar epithelial type II cell differentiation.

In this study, we report on the noninvasive identification of spectral markers of alveolar type II (ATII) cell differentiation in vitro using Raman microspectroscopy. ATII cells are progenitor cells for alveolar type I (ATI) cells in vivo, and spontaneously differentiate toward an ATI-like phenotype in culture. We analyzed undifferentiated and differentiated primary human ATII cells, and correlated Raman spectral changes to cellular changes in morphology and marker protein synthesis (surfactant protein C, alkaline phosphatase, caveolin-1). Undifferentiated ATII cells demonstrated spectra with strong phospholipid vibrations, arising from alveolar surfactant stored within cytoplasmic lamellar bodies (Lbs). Differentiated ATI-like cells yielded spectra with significantly less lipid content. Factor analysis revealed a phospholipid-dominated spectral component as the main discriminator between the ATII and ATI-like phenotypes. Spectral modeling of the data revealed a significant decrease in the spectral contribution of cellular lipids-specifically phosphatidyl choline, the main constituent of surfactant, as ATII cells differentiate. These observations were consistent with the clearance of surfactant from Lbs as ATII cells differentiate, and were further supported by cytochemical staining for Lbs. These results demonstrate the first spectral characterization of primary human ATII cells, and provide insight into the biochemical properties of alveolar surfactant in its unperturbed cellular environment.

Immortalization of human alveolar epithelial cells to investigate nanoparticle uptake.

Primary human alveolar type 2 (AT2) cells were immortalized by transduction with the catalytic subunit of telomerase and simian virus 40 large-tumor antigen. Characterization by immunochemical and morphologic methods demonstrated an AT1-like cell phenotype. Unlike primary AT2 cells, immortalized cells no longer expressed alkaline phosphatase, pro-surfactant protein C, and thyroid transcription factor-1, but expressed increased caveolin-1 and receptor for advanced glycation end products (RAGE). Live cell imaging using scanning ion conductance microscopy showed that the cuboidal primary AT2 cells were approximately 15 microm and enriched with surface microvilli, while the immortal AT1 cells were attenuated more than 40 microm, resembling these cells in situ. Transmission electron microscopy highlighted the attenuated morphology and showed endosomal vesicles in some immortal AT1 cells (but not primary AT2 cells) as found in situ. Particulate air pollution exacerbates cardiopulmonary disease. Interaction of ultrafine, nano-sized particles with the alveolar epithelium and/or translocation into the cardiovasculature may be a contributory factor. We hypothesized differential uptake of nanoparticles by AT1 and AT2 cells, depending on particle size and surface charge. Uptake of 50-nm and 1-microm fluorescent latex particles was investigated using confocal microscopy and scanning surface confocal microscopy of live cells. Fewer than 10% of primary AT2 cells internalized particles. In contrast, 75% immortal AT1 cells internalized negatively charged particles, while less than 55% of these cells internalized positively charged particles; charge, rather than size, mattered. The process was rapid: one-third of the total cell-associated negatively charged 50-nm particle fluorescence measured at 24 hours was internalized during the first hour. AT1 cells could be important in translocation of particles from the lung into the circulation.