Characterization of chemical reactions of silver diammine fluoride and hydroxyapatite under remineralization conditions

Introduction

Silver Diammine Fluoride (SDF) is a clinically used topical agent to arrest dental caries. However, the kinetics of its chemical interactions with hydroxyapatite (HA), the principal inorganic component of dental enamel, are not known. The aim was to characterize the step-wise chemical interactions between SDF and HA powder during the clinically important process of remineralization.

Methods

Two grams of HA powder were immersed in 10 ml acetic acid pH = 4.0 for 2 h to mimic carious demineralization. The powder was then washed and dried for 24 h and mixed with 1.5 ml SDF (Riva Star) for 1 min. The treated powder was then air-dried for 3 min, and 0.2 g was removed and stored in individual tubes each containing 10 ml remineralizing solution. Powder was taken from each tube at various times of exposure to remineralization solution (0 min, 10 min, 2 h, 4 h, 8 h, 24 h, and 10 days), and characterized using Magic Angle Spinning-Nuclear Magnetic Resonance (MAS-NMR) spectroscopy.

Results and discussion

19F MAS-NMR spectra showed that calcium fluoride (CaF2) started to form almost immediately after HA was in contact with SDF. After 24 h, the peak shifted to -104.5 ppm suggesting that fluoride substituted hydroxyapatite (FSHA) was formed with time at the expense of CaF2. The 31P MAS-NMR spectra showed a single peak at 2.7 ppm at all time points showing that the only phosphate species present was crystalline apatite. The 35Cl MAS-NMR spectra showed formation of silver chloride (AgCl) at 24 h. It was observed that after the scan, the whitish HA powder changed to black color. In conclusion, this time sequence study showed that under remineralization conditions, SDF initially reacted with HA to form CaF2 which is then transformed to FSHA over time. In the presence of chloride, AgCl is formed which is subsequently photo-reduced to black metallic silver.

Administration of intestinal mesenchymal stromal cells reduces colitis-associated cancer in C57BL/6J mice modulating the immune response and gut dysbiosis

BACKGROUND

Patients with inflammatory bowel disease (IBD) have a higher risk of developing colitis-associated colorectal cancer (CAC) with poor prognosis. IBD etiology remains undefined but involves environmental factors, genetic predisposition, microbiota imbalance (dysbiosis) and mucosal immune defects. Mesenchymal stromal cell (MSC) injections have shown good efficacy in reducing intestinal inflammation in animal and human studies. However, their effect on tumor growth in CAC and their capacity to restore gut dysbiosis are not clear.

METHODS

The outcome of systemic administrations of in vitro expanded human intestinal MSCs (iMSCs) on tumor growth in vivo was evaluated using the AOM/DSS model of CAC in C57BL/6J mice. Innate and adaptive immune responses in blood, mesenteric lymph nodes (MLNs) and colonic tissue were analyzed by flow cytometry. Intestinal microbiota composition was evaluated by 16S rRNA amplicon sequencing.

RESULTS

iMSCs significantly inhibited colitis and intestinal tumor development, reducing IL-6 and COX-2 expression, and IL-6/STAT3 and PI3K/Akt signaling. iMSCs decreased colonic immune cell infiltration, and partly restored intestinal monocyte homing and differentiation. iMSC administration increased the numbers of Tregs and IFN-γ+CD8+ T cells in the MLNs while decreasing the IL-4+Th2 response. It also ameliorated intestinal dysbiosis in CAC mice, increasing diversity and Bacillota/Bacteroidota ratio, as well as Akkermansia abundance, while reducing Alistipes and Turicibacter, genera associated with inflammation.

CONCLUSION

Administration of iMSCs protects against CAC, ameliorating colitis and partially reverting intestinal dysbiosis, supporting the use of MSCs for the treatment of IBD.

Incidence, Management Experience and Characteristics of Patients with Giardiasis and Common Variable Immunodeficiency

Common variable immunodeficiency (CVID) is an antibody immunodeficiency with a wide variety of clinical and immunological manifestations, and whose genetic cause is found in about 25% of diagnosed cases. Giardia lamblia is one of the main causes of gastrointestinal infections in CVID. 5-Nitroimidazoles are the most used first-line treatment, but nitroimidazole-refractory giardiasis is increasing. Nevertheless, only a few cases of refractory giardiasis in CVID have been reported. This study aimed to determine the incidence of Giardia infection in our CVID cohort, shows our management experience and describes patients' phenotypic features. Clinical data collection, immunological, immunogenetics and microbiology assays were performed, and previous cases of giardiasis in CVID were reviewed. The incidence of symptomatic giardiasis was 12.9%. The main immunological features were undetectable or decreased IgA levels and reduced switched memory B cells. A probable PTEN pathogenic variant was detected in one. Three patients responded to metronidazole but suffered reinfections, and one was a refractory giardiasis eradicated with innovative quinacrine plus paromomycin combination. This work could contribute to the decision-making and therapeutic management of future patients with CVID and giardiasis, highlighting the importance of the early detection and treatment of infections in patients with CVID to ensure a good quality of life.

Realist analysis of whether emergency departments with primary care services generate 'provider-induced demand'

Background

It is not known whether emergency departments (EDs) with primary care services influence demand for non-urgent care (‘provider-induced demand’). We proposed that distinct primary care services in EDs encourages primary care demand, whereas primary care integrated within EDs may be less likely to cause additional demand. We aimed to explore this and explain contexts (C), mechanisms (M) and outcomes (O) influencing demand.

Methods

We used realist evaluation methodology and observed ED service delivery. Twenty-four patients and 106 staff members (including Clinical Directors and General Practitioners) were interviewed at 13 EDs in England and Wales (240 hours of observations across 30 days). Field notes from observations and interviews were analysed by creating ‘CMO’ configurations to develop and refine theories relating to drivers of demand.

Results

EDs with distinct primary care services were perceived to attract demand for primary care because services were visible, known or enabled direct access to health care services. Other influencing factors included patients’ experiences of accessing primary care, community care capacity, service design and population characteristics.

Conclusions

Patient, local-system and wider-system factors can contribute to additional demand at EDs that include primary care services. Our findings can inform service providers and policymakers in developing strategies to limit the effect of potential influences on additional demand when demand exceeds capacity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-022-00709-2.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Major Histocompatibility Complex Class I Chain-Related α (MICA) STR Polymorphisms in COVID-19 Patients

The SARS-CoV-2 disease presents different phenotypes of severity. Comorbidities, age, and being overweight are well established risk factors for severe disease. However, innate immunity plays a key role in the early control of viral infections and may condition the gravity of COVID-19. Natural Killer (NK) cells are part of innate immunity and are important in the control of virus infection by killing infected cells and participating in the development of adaptive immunity. Therefore, we studied the short tandem repeat (STR) transmembrane polymorphisms of the major histocompatibility complex class I chain-related A (MICA), an NKG2D ligand that induces activation of NK cells, among other cells. We compared the alleles and genotypes of MICA in COVID-19 patients versus healthy controls and analyzed their relation to disease severity. Our results indicate that the MICA*A9 allele is related to infection as well as to symptomatic disease but not to severe disease. The MICA*A9 allele may be a risk factor for SARS-CoV-2 infection and symptomatic disease.

Copy Neutral LOH Affecting the Entire Chromosome 6 Is a Frequent Mechanism of HLA Class I Alterations in Cancer

Total or partial loss of HLA class I antigens reduce the recognition of specific tumor peptides by cytotoxic T lymphocytes favoring cancer immune escape during natural tumor evolution. These alterations can be caused by genomic defects, such as loss of heterozygosity at chromosomes 6 and 15 (LOH-6 and LOH-15), where HLA class I genes are located. There is growing evidence indicating that LOH in HLA contributes to the immune selection of HLA loss variants and influences the resistance to immunotherapy. Nevertheless, the incidence and the mechanism of this chromosomal aberration involving HLA genes has not been systematically assessed in different types of tumors and often remains underestimated. Here, we used SNP arrays to investigate the incidence and patterns of LOH-6 and LOH-15 in a number of human cancer cell lines and tissues of different histological types. We observed that LOH in HLA is a common event in cancer samples with a prevalence of a copy neutral type of LOH (CN-LOH) that affects entire chromosome 6 or 15 and involves chromosomal duplications. LOH-6 was observed more often and was associated with homozygous HLA genotype and partial HLA loss of expression. We also discuss the immunologic and clinical implications of LOH in HLA on tumor clonal expansion and association with the cancer recurrence after treatment.

Intestinal mesenchymal cells regulate immune responses and promote epithelial regeneration in vitro and in dextran sulfate sodium-induced experimental colitis in mice

AIM

Disruption of the intestinal mucosal tolerance, that is, the immunological unresponsiveness to innocuous food antigens and the commensal microbiota, in the colon is associated with several chronic diseases including inflammatory bowel disease (IBD). Understanding the mechanisms responsible for intestinal mucosal tolerance has potential translational value for its therapy and management. Human intestinal mesenchymal cells (iMCs) play important roles in colonic mucosal tolerance, but further studies on their tissue regenerative and immunomodulatory capacities are necessary in order to fully understand their function in health and disease.

METHODS

In this study, we have isolated and analysed the capacity of human iMCs to promote wound healing and modulate immune responses in vitro and in vivo, using the dextran sulfate sodium (DSS)-induced colitis model.

RESULTS

Cultured iMCs were CD45^- CD73⁺ CD90⁺ CD105⁺ and accelerated the wound closure in a normal colon mucosa (NCM) 356 human epithelial cell wound healing assay. Furthermore, iMCs blocked the LPS-mediated induction of TNF-α in THP-1 macrophages and inhibited the proliferation of peripheral blood mononuclear cells, partly through the induction of indoleamine-2,3-dioxygenase. In DSS colitic mice, iMCs administration reduced the disease activity index and ameliorated intestinal tissue damage and permeability. Furthermore, iMCs reduced intestinal inflammation, evidenced by a decreased mRNA expression of pro-inflammatory cytokines, reduced IL-1β secretion by intestinal explants and inhibited colonic iNOS protein expression.

CONCLUSIONS

Our data show that human iMCs isolated from the noninflamed intestine possess tissue-regenerative and immunomodulatory capacities that could potentially be harnessed/restored in order to reduce IBD severity.

An Exploratory Study of the Texture Research Investigational Platform (TRIP) to Evaluate Bone Texture Score of Distal Femur DXA Scans - A TBS-Based Approach

Poor bone status is associated with increased complications following orthopedic surgery. Therefore, assessing site-specific skeletal status prior to or after orthopedic surgery to optimize outcomes is appealing. The trabecular bone score (TBS) approach, a surrogate for microarchitecture, was adapted to the Texture Research Investigational Platform (TRIP), which allows assessment of many skeletal sites imaged by various modalities. TRIP generates a bone texture score (TBS ORTHO), which could potentially guide surgical decision-making and offer insight into postsurgical fracture risk. As distal femur bone loss occurs following total knee arthroplasty (TKA), we hypothesized that TBS ORTHO after TKA would identify poorer texture in the operated femur compared to the nonoperated. We evaluated 30 subjects (15 M/15 F) with unilateral TKA 2-5 yr previously, mean age 67.9 yr and body mass index 30 kg/m². Using a Lunar iDXA, lumbar spine and entire femur scans were obtained, the latter using the atypical femur fracture feature. Distal femur bone mineral density (BMD) and TBS ORTHO were obtained using manual regions of interest (ROI) at 15% and 25% of leg length from the intercondylar notch. TBS ORTHO was determined using distal femur DICOM images and TRIP v1.0 (Medimaps, France). Differences in operated vs nonoperated femur were evaluated by paired t test. As previously reported, operated leg BMD was approx 10% lower at 15% and 25% ROIs. Similarly, TBS ORTHO values in the operated leg were approx 5% lower (p < 0.05) at these same ROIs. Distal femur TBS ORTHO and BMD were largely unrelated. TBS ORTHO reproducibility at these ROIs was approx 3.5%. In conclusion, this pilot study documents the feasibility of reproducibly obtaining distal femur TBS ORTHO values. Lower values were observed in the surgical leg, consistent with the bone loss that follows TKA. Further work is indicated to refine TRIP use and evaluate whether such data provides guidance for surgical decision-making and improves periprosthetic fracture prediction.

Negative Clinical Evolution in COVID-19 Patients Is Frequently Accompanied With an Increased Proportion of Undifferentiated Th Cells and a Strong Underrepresentation of the Th1 Subset

The severity of SARS-CoV-2 infection has been related to uncontrolled inflammatory innate responses and impaired adaptive immune responses mostly due to exhausted T lymphocytes and lymphopenia. In this work we have characterized the nature of the lymphopenia and demonstrate a set of factors that hinder the effective control of virus infection and the activation and arming of effector cytotoxic T CD8 cells and showing signatures defining a high-risk population. We performed immune profiling of the T helper (Th) CD4+ and T CD8+ cell compartments in peripheral blood of 144 COVID-19 patients using multiparametric flow cytometry analysis. On the one hand, there was a consistent lymphopenia with an overrepresentation of non-functional T cells, with an increased percentage of naive Th cells (CD45RA+, CXCR3-, CCR4-, CCR6-, CCR10-) and persistently low frequency of markers associated with Th1, Th17, and Th1/Th17 memory-effector T cells compared to healthy donors. On the other hand, the most profound alteration affected the Th1 subset, which may explain the poor T cells responses and the persistent blood virus load. Finally, the decrease in Th1 cells may also explain the low frequency of CD4+ and CD8+ T cells that express the HLA-DR and CD38 activation markers observed in numerous patients who showed minimal or no lymphocyte activation response. We also identified the percentage of HLA-DR+CD4+ T cells, PD-1+CD+4/CD8+ T cells in blood, and the neutrophil/lymphocyte ratio as useful factors for predicting critical illness and fatal outcome in patients with confirmed COVID-19.

The logistical management of tertiary urethral disease in the United Kingdom: Implications from an online audit of male reconstructive urethral surgery

Objective:

To determine those patient groupings, based on volume and risk, whose optimal urethral reconstructive management might be provided by a reorganisation of UK reconstructive surgeons.

Methods:

Between 2010 and 2017, ~689 men/year were enrolled onto an online audit platform collecting data about urethral reconstruction in the UK; this accrual was compared against hospital episode statistics (HES). The available workforce, and where this was based, was collected. Individual and institutional incumbent patient volumes, pathology, surgical complexity and outcomes from treatment were collated to stratify volume/risk groups.

Results:

More than 90% of all HES-recorded data were accrued, being provided by 50 surgeons at 39 operative sites. Most reconstructive surgery was provided at 10 centres performing >20 procedures/year. More than 50% of all interventions were of a high-volume low-risk type. Of activity, 32.3% was intermediate volume or moderate risk, and 12.5% of men presented for lower-volume or higher-risk procedures.

Conclusion:

Correlation of detailed volume/outcome data allows the definition of patient populations presenting for urethral reconstruction. Stratification of each group’s management, to optimise the surgical outcome, may be applied to a hierarchical service delivery model based on the complexity of the patient’s presenting urethral pathology.

Level of evidence:

Level IV

GARP is a key molecule for mesenchymal stromal cell responses to TGF-β and fundamental to control mitochondrial ROS levels

Multipotent mesenchymal stromal cells (MSCs) have emerged as a promising cell therapy in regenerative medicine and for autoimmune/inflammatory diseases. However, a main hurdle for MSCs-based therapies is the loss of their proliferative potential in vitro. Here we report that glycoprotein A repetitions predominant (GARP) is required for the proliferation and survival of adipose-derived MSCs (ASCs) via its regulation of transforming growth factor-β (TGF-β) activation. Silencing of GARP in human ASCs increased their activation of TGF-β which augmented the levels of mitochondrial reactive oxygen species (mtROS), resulting in DNA damage, a block in proliferation and apoptosis. Inhibition of TGF-β signaling reduced the levels of mtROS and DNA damage and restored the ability of GARP-/low ASCs to proliferate. In contrast, overexpression of GARP in ASCs increased their proliferative capacity and rendered them more resistant to etoposide-induced DNA damage and apoptosis, in a TGF-β-dependent manner. In summary, our data show that the presence or absence of GARP on ASCs gives rise to distinct TGF-β responses with diametrically opposing effects on ASC proliferation and survival.

Complex abdominal wall hernia repair with biologic mesh in elderly: a propensity matched analysis

Background

Complex abdominal wall reconstruction (CAWR) has become a common surgical procedure both in non-elderly and elderly patients.

Objective

The aim of this study is to analyze the outcomes of the elderly compared to nonelderly undergoing CAWR using propensity score matching.

Methods

All patients who underwent CAWR using porcine-derived, non-crosslinked acellular dermal matrix (ADM) (Strattice™) between January 2014 and July 2017 were studied retrospectively. Propensity matched analysis was performed for risk adjustment in multivariable analysis and for one-to-one matching. The outcomes were analyzed for differences in postoperative complications, reoperations, mortality, hospital length of stay and adverse discharge disposition.

Results

One hundred-thirty-six patients were identified during the study period. Non-elderly (aged 18–64 years) constituted 70% (n = 95) and elderly (aged ≥ 65 years) comprised 30% of the overall patient population (n = 41). Seventy-three (56.7%) were females. After adjustment through the propensity score, which included 35 pairs, the surgical site infection (p = 1.000), wound necrosis (p = 1.000), the need for mechanical ventilation (p = 0.259), mortality (p = 0.083), reoperation rate (p = 0.141), hospital length of stay (p = 0.206), and discharge disposition (p = 0.795) were similar.

Conclusion

Elderly patients undergoing CAWR with biological mesh have comparable outcomes with non-elderly patients when using propensity matching score.

The Importance of the Microbiome in Critically Ill Patients: Role of Nutrition

Critically ill patients have an alteration in the microbiome in which it becomes a disease-promoting pathobiome. It is characterized by lower bacterial diversity, loss of commensal phyla, like Firmicutes and Bacteroidetes, and a domination of pathogens belonging to the Proteobacteria phylum. Although these alterations are multicausal, many of the treatments administered to these patients, like antibiotics, play a significant role. Critically ill patients also have a hyperpermeable gut barrier and dysregulation of the inflammatory response that favor the development of the pathobiome, translocation of pathogens, and facilitate the emergence of sepsis. In order to restore the homeostasis of the microbiome, several nutritional strategies have been evaluated with the aim to improve the management of critically ill patients. Importantly, enteral nutrition has proven to be more efficient in promoting the homeostasis of the gut microbiome compared to parenteral nutrition. Several nutritional therapies, including prebiotics, probiotics, synbiotics, and fecal microbiota transplantation, are currently being used, showing variable results, possibly due to the unevenness of clinical trial conditions and the fact that the beneficial effects of probiotics are specific to particular species or even strains. Thus, it is of great importance to better understand the mechanisms by which nutrition and supplement therapies can heal the microbiome in critically ill patients in order to finally implement them in clinical practice with optimal safety and efficacy.

Validation of Three Rapid Screening Methods for Detection of Verotoxin-Producing Escherichia coli in Foods: Interlaboratory Study

An interlaboratory study was conducted for the validation of 3 methods for the detection of all verotoxin-producing Escherichia coli (VTEC) in foods. The methods were a multi-analyte 1-step lateral flow immunoassay (LFIA) for detection of E. coli O157 and verotoxin (VT); an enzyme-linked immunosorbent assay targeted against VT1, VT2, and VT2c (VT-ELISA); and a polymerase chain reaction (PCR) method for detection of VT genes (VT-PCR). Aliquots (25 g or 25 mL) of 4 food types (raw minced [ground] beef, unpasteurized milk, unpasteurized apple juice [cider], and salami) were individually inoculated with low numbers (&lt;9 to 375 cells/25 g) of 6 test strains of E. coli (serogroups O26, O103, O111, O145, and O157) with differing VT-producing capabilities. Five replicates for each test strain and 5 uninoculated samples were prepared for each food type. Fourteen participating laboratories analyzed samples using the LFIA, 9 analyzed the samples by ELISA, and 9 by PCR. The LFIA for O157 and VT had a specificity (correct identification of negative samples) of 92 and 94%, respectively, and a sensitivity (correct identification of positive samples) of 94 and 55%, respectively. The VT-ELISA and VT-PCR

Estimating the cost impact of dressing choice in the context of a mass burns casualty event

Mass casualty burn events (MCBs) require intense and complex management. Silver-infused longer use dressings might help optimise management of burns in an MCB setting. We developed a model estimating the impact of dressing choice in the context of an MCB. The model was developed in Excel in collaboration with experienced emergency response clinicians. The model compares use of silver-infused dressings with use of traditional dressings in patients with partial thickness burns covering 30% of their body. Costs were estimated from a UK perspective as a proxy for a funded emergency response team and limited to cost of dressings, bandages, padding, analgesia and staff time. Expected patient costs and resource use were summarised over an acute 2-week intervention period and extrapolated to estimate possible time savings in a hypothetical MCB. Per patient costs were estimated at £2,002 (silver) and £1,124 (traditional) (a daily additional spend of £63). Per patient staff time was estimated at 864 minutes (silver) and 1,200 minutes (traditional) (a daily time saving of 24 minutes). Multiplying up to a possible MCB population of 20 could result in a saving equivalent to 9 staff shifts over the 2-week intervention period. The model was sensitive to type of silver dressing, frequency of dressing change and staff costs. We found increased costs through use of silver dressings but time savings that might help optimise burns management in an MCB. Exploring the balance between costs and staff time might help future MCB response preparation.

Expression of Musashi-1 During Osteogenic Differentiation of Oral MSC: An In Vitro Study

Background: Musashi-1 (MSI1) is a negative regulator of mesenchymal stromal cell (MSC) differentiation which in turn favors cell proliferation. However, little is known about its expression by MSC from the oral cavity and in the context of osteogenic differentiation. Aim: The aim of this study was to analyze the expression of MSI1 in the context of osteogenic differentiation of MSC derived from the oral cavity. Material/methods: For this in vitro study, MSC were isolated from six different origins of the oral cavity. They were extensively characterized in terms of proliferative and clonogenicity potential, expression of stemness genes (MYC, NANOG, POU5F1, and SOX2), expression of surface markers (CD73, CD90, CD105, CD14, CD31, CD34, and CD45) and adipo-, chondro- and osteogenic differentiation potential. Then, osteogenic differentiation was induced and the expression of MSI1 mRNA and other relevant markers of osteogenic differentiation, including RUNX2 and Periostin, were also evaluated. Results: Cell populations from the alveolar bone (pristine or previously grafted with xenograft), dental follicle, dental germ, dental pulp, and periodontal ligament were obtained. The analysis of proliferative and clonogenicity potential, expression of the stemness genes, expression of surface markers, and differentiation potential showed similar characteristics to those of previously published MSC from the umbilical cord. Under osteogenic differentiation conditions, all MSC populations formed calcium deposits and expressed higher SPARC. Over time, the expression of MSI1 followed different patterns for the different MSC populations. It was not significantly different than the expression of RUNX2. In contrast, the expression of MSI1 and POSTN and RUNX2 were statistically different in most MSC populations. Conclusion: In the current study, a similar expression pattern of MSI1 and RUNX2 during in vitro osteogenic differentiation was identified.

DXA evaluation of femoral bone mineral density and cortical width in patients with prior total knee arthroplasty

Periprosthetic fractures after total knee arthroplasty (TKA) have devastating consequences. Osteoporosis increases periprosthetic fracture risk, but distal femur bone mineral density (BMD) is not measured post-TKA. This study measured distal femur BMD and cortical width; both were lower in the TKA compared to the non-operated leg. BMD measurement reproducibility was good. Standardized DXA regions of interest are proposed.

INTRODUCTION

Periprosthetic fractures following total knee arthroplasty (TKA) are not rare. We hypothesized that TKA is associated with low BMD, potentially increasing periprosthetic fracture risk. However, distal femur dual energy x-ray (DXA) measurement is virtually never performed after TKA due to lack of standardized approaches. Thus, this study's aims were to develop standard DXA femur regions of interest (ROIs), assess cortical width, and determine measurement reproducibility in TKA patients.

METHODS

Thirty adults (15 M/15 F) age 59-80 years with unilateral, primary TKA within 2-5 years had femoral DXA scans performed in duplicate using a Lunar iDXA densitometer. In prior work, we established that femur BMD was lowest in the distal metaphysis and highest in mid-shaft. Thus, BMD and cortical width were measured at 15%, 25%, and 60% of the femur length measured from the distal notch. Femur BMD and cortical width were compared between limbs (TKA vs. non-operated side) by paired t test.

RESULTS

BMD was 3.2-9.9% lower (p < 0.001) in the operated femur at all custom ROIs; substantial between individual differences existed with some up to 30% lower. Cortical width was lower (p < 0.05) at the 25% ROI on the TKA side. BMD reproducibility was excellent; CV 0.85-1.33%.

CONCLUSIONS

Distal femur BMD can be reproducibly measured using DXA and is ~ 10% lower on the TKA leg. Similarly, medial and lateral cortices are thinner at the 25% ROI. These bone changes likely increase periprosthetic fracture risk. Further work to define and mitigate periprosthetic fracture risk after TKA is needed.

The IS2 Element Improves Transcription Efficiency of Integration-Deficient Lentiviral Vector Episomes

Integration-defective lentiviral vectors (IDLVs) have become an important alternative tool for gene therapy applications and basic research. Unfortunately, IDLVs show lower transgene expression as compared to their integrating counterparts. In this study, we aimed to improve the expression levels of IDLVs by inserting the IS2 element, which harbors SARs and HS4 sequences, into their LTRs (SE-IS2-IDLVs). Contrary to our expectations, the presence of the IS2 element did not abrogate epigenetic silencing by histone deacetylases. In addition, the IS2 element reduced episome levels in IDLV-transduced cells. Interestingly, despite these negative effects, SE-IS2-IDLVs outperformed SE-IDLVs in terms of percentage and expression levels of the transgene in several cell lines, including neurons, neuronal progenitor cells, and induced pluripotent stem cells. We estimated that the IS2 element enhances the transcriptional activity of IDLV LTR circles 6- to 7-fold. The final effect the IS2 element in IDLVs will greatly depend on the target cell and the balance between the negative versus the positive effects of the IS2 element in each cell type. The better performance of SE-IS2-IDLVs was not due to improved stability or differences in the proportions of 1-LTR versus 2-LTR circles but probably to a re-positioning of IS2-episomes into transcriptionally active regions.

Finding the weakest link: mechanical sensitivity in a fish cranial linkage system

Understanding the physical mechanics behind morphological systems can offer insights into their evolution. Recent work on linkage systems in fish and crustaceans has suggested that the evolution of such systems may depend on mechanical sensitivity, where geometrical changes to different parts of a biomechanical system have variable influence on mechanical outputs. While examined at the evolutionary level, no study has directly explored this idea at the level of the mechanism. We analyse the mechanical sensitivity of a fish cranial linkage to identify the influence of linkage geometry on the kinematic transmission (KT) of the suspensorium, hyoid and lower jaw. Specifically, we answer two questions about the sensitivity of this linkage system: (i) What changes in linkage geometry affect one KT while keeping the other KTs constant? (ii) Which geometry changes result in the largest and smallest changes to KT? Our results show that there are ways to alter the morphology that change each KT individually, and that there are multiple ways to alter a single link that have variable influence on KT. These results provide insight into the morphological evolution of the fish skull and highlight which structural features in the system may have more freedom to evolve than others.

Exosomes derived from mesenchymal stem cells enhance radiotherapy-induced cell death in tumor and metastatic tumor foci

BACKGROUND

We have recently shown that radiotherapy may not only be a successful local and regional treatment but, when combined with MSCs, may also be a novel systemic cancer therapy. This study aimed to investigate the role of exosomes derived from irradiated MSCs in the delay of tumor growth and metastasis after treatment with MSC + radiotherapy (RT).

METHODS

We have measured tumor growth and metastasis formation, of subcutaneous human melanoma A375 xenografts on NOD/SCID-gamma mice, and the response of tumors to treatment with radiotherapy (2 Gy), mesenchymal cells (MSC), mesenchymal cells plus radiotherapy, and without any treatment. Using proteomic analysis, we studied the cargo of the exosomes released by the MSC treated with 2 Gy, compared with the cargo of exosomes released by MSC without treatment.

RESULTS

The tumor cell loss rates found after treatment with the combination of MSC and RT and for exclusive RT, were: 44.4% % and 12,1%, respectively. Concomitant and adjuvant use of RT and MSC, increased the mice surviving time 22,5% in this group, with regard to the group of mice treated with exclusive RT and in a 45,3% respect control group. Moreover, the number of metastatic foci found in the internal organs of the mice treated with MSC + RT was 60% less than the mice group treated with RT alone. We reasoned that the exosome secreted by the MSC, could be implicated in tumor growth delay and metastasis control after treatment.

CONCLUSIONS

Our results show that exosomes derived form MSCs, combined with radiotherapy, are determinant in the enhancement of radiation effects observed in the control of metastatic spread of melanoma cells and suggest that exosome-derived factors could be involved in the bystander, and abscopal effects found after treatment of the tumors with RT plus MSC. Radiotherapy itself may not be systemic, although it might contribute to a systemic effect when used in combination with mesenchymal stem cells owing the ability of irradiated MSCs-derived exosomes to increase the control of tumor growth and metastasis.

TGF-β and mesenchymal stromal cells in regenerative medicine, autoimmunity and cancer

Multipotent mesenchymal stromal cells (MSCs) represent a promising cell-based therapy in regenerative medicine and for the treatment of inflammatory/autoimmune diseases. Importantly, MSCs have emerged as an important contributor to the tumor stroma with both pro- and anti-tumorigenic effects. However, the successful translation of MSCs to the clinic and the prevention of their tumorigenic and metastatic effect require a greater understanding of factors controlling their proliferation, differentiation, migration and immunomodulation in vitro and in vivo. The transforming growth factor(TGF)-β1, 2 and 3 are involved in almost every aspect of MSC function. The aim of this review is to highlight the roles that TGF-β play in the biology and therapeutic applications of MSCs. We will discuss the how TGF-β modulate MSC function as well as the paracrine effects of MSC-derived TGF-β on other cell types in the context of tissue regeneration, immune responses and cancer. Finally, taking all these aspects into consideration we discuss how modulation of TGF-β signaling/production in MSCs could be of clinical interest.

Improving screening and brief intervention activities in primary health care: Secondary analysis of professional accuracy based on the AUDIT-C

INTRODUCTION AND OBJECTIVE

The ODHIN trial found that training and support and financial reimbursement increased the proportion of patients that were screened and given advice for their heavy drinking in primary health care. However, the impact of these strategies on professional accuracy in delivering screening and brief advice is underresearched and is the focus of this paper.

METHOD

From 120 primary health care units (24 in each jurisdiction: Catalonia, England, the Netherlands, Poland, and Sweden), 746 providers participated in the baseline and the 12-week implementation periods. Accuracy was measured in 2 ways: correctness in completing and scoring the screening instrument, AUDIT-C; the proportion of screen-negative patients given advice, and the proportion of screen-positive patients not given advice. Odds ratios of accuracy were calculated for type of profession and for intervention group: training and support, financial reimbursement, and internet-based counselling.

RESULTS

Thirty-two of 36 711 questionnaires were incorrectly completed, and 65 of 29 641 screen-negative patients were falsely classified. At baseline, 27% of screen-negative patients were given advice, and 22.5% screen-positive patients were not given advice. These proportions halved during the 12-week implementation period, unaffected by training. Financial reimbursement reduced the proportion of screen-positive patients not given advice (OR = 0.56; 95% CI, 0.31-0.99; P < .05).

CONCLUSION

Although the use of AUDIT-C as a screening tool was accurate, a considerable proportion of risky drinkers did not receive advice, which was reduced with financial incentives.

Enhanced Survival of Porcine Neural Xenografts in Mice Lacking CD1d1, But No Effect of NK1.1 Depletion

Transplantation of embryonic porcine neurons may restore neurological function in patients with Parkinson's disease, if immunological rejection could be prevented. This study was performed to investigate the role of natural killer cells (NK cells) and NK1.1+ T cells (NK T cells) in the rejection of neural xenografts. A cell suspension was prepared from the ventral mesencephalon of 26 – 27-day-old pig embryos, and 2 μl was implanted in the right striata of mutant CD1d1 null (CD1.1-/-) mice, NK1.1-depleted mice, and controls. The CD1.1-/- mice are deficient in NK T cells and the antigen-presenting molecule CD1d1. Graft survival and host responses were determined immunohistochemically using markers for dopamine neurons, CD4-, CD8- cells, microglia, and macrophages. At 2 weeks, the grafts were significantly larger in CD1.1-/- mice, 0.09 ± 0.02 μl (mean ± SEM), compared with controls, 0.05 ± 0.01 μl. There was no significant difference between NK1.1-depleted mice, 0.02 ± 0.01 μl, and controls. At 5 weeks, two grafts were still present in the CD1-/- mice, whereas only scars remained in the controls and in the NK1.1-depleted mice. Immune reactions were strong at 2 weeks and less pronounced at 5 weeks in all groups. Microglial activation was lower in NK-depleted mice than in the controls at 2 weeks. In contrast to organ xenografting, NK1.1+ cells do not seem to be important mediators of the rejection of discordant cellular neural xenografts. However, our results suggest that the antigen-presenting molecule CD1d1 may be involved in the rejection process.

Scintillate: An open-source graphical viewer for time-series calcium imaging evaluation and pre-processing

BACKGROUND

Calcium imaging is based on the detection of minute signal changes in an image time-series encompassing pre- and post-stimuli. Depending on the function of the elicited response, change may be pronounced, as in the case of a genetically encoded calcium-reporter protein, or subtle, as is the case in a bath-applied dye system. Large datasets are thus often acquired and appraised only during post-processing where specific Regions of Interest (ROIs) are examined.

NEW METHOD

The scintillate software provides a platform allowing for near instantaneous viewing of time-sequenced tiffs within a discrete GUI environment. Whole sequences may be evaluated. In its simplest form scintillate provides change in florescence (ΔF) across the entire tiff image matrix. Evaluating image intensity level differences across the whole image allows the user to rapidly establish the value of the preparation, without a priori ROI-selection. Additionally, an implementation of Independent Component Analysis (ICA) provides additional rapid insights into areas of signal change.

RESULTS

We imaged transgenic flies expressing Calcium-sensitive reporter proteins within projection neurons and moth mushroom bodies stained with a Ca²⁺ sensitive bath-applied dye. Instantaneous pre-stimulation background subtraction allowed us to appraise strong genetically encoded neuronal Ca²⁺ responses in flies and weaker, less apparent, responses within moth mushroom bodies.

COMPARISON WITH EXISTING METHODS

At the time of acquisition, whole matrix ΔF analysis alongside ICA is ordinarily not performed. We found it invaluable, minimising time spent with unresponsive samples, and assisting in optimisation of subsequent acquisitions.

CONCLUSIONS

We provide a multi-platform open-source system to evaluate time-series images.

Impact of primary healthcare providers' initial role security and therapeutic commitment on implementing brief interventions in managing risky alcohol consumption: a cluster randomised factorial trial

BACKGROUND

Brief interventions in primary healthcare are cost-effective in reducing drinking problems but poorly implemented in routine practice. Although evidence about implementing brief interventions is growing, knowledge is limited with regard to impact of initial role security and therapeutic commitment on brief intervention implementation.

METHODS

In a cluster randomised factorial trial, 120 primary healthcare units (PHCUs) were randomised to eight groups: care as usual, training and support, financial reimbursement, and the opportunity to refer patients to an internet-based brief intervention (e-BI); paired combinations of these three strategies, and all three strategies combined. To explore the impact of initial role security and therapeutic commitment on implementing brief interventions, we performed multilevel linear regression analyses adapted to the factorial design.

RESULTS

Data from 746 providers from 120 PHCUs were included in the analyses. Baseline role security and therapeutic commitment were found not to influence implementation of brief interventions. Furthermore, there were no significant interactions between these characteristics and allocated implementation groups.

CONCLUSIONS

The extent to which providers changed their brief intervention delivery following experience of different implementation strategies was not determined by their initial attitudes towards alcohol problems. In future research, more attention is needed to unravel the causal relation between practitioners' attitudes, their actual behaviour and care improvement strategies to enhance implementation science.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01501552.

Data set for diet specific differential gene expression analysis in three Spodoptera moths

Examination of closely related species pairs is suggested for evolutionary comparisons of different degrees of polyphagy, which we did here with three taxa of lepidopteran herbivores, Spodoptera spp (S. littoralis, S. frugiperda maize (C) and rice (R) strains) for a RNAseq analysis of the midguts from the 3rd instar insect larvae for differential metabolic responses after feeding on pinto bean based artificial diet vs maize leaves. Paired-end (2×100 bp) Illumina HiSeq2500 sequencing resulted in a total of 24, 23, 24, and 21 million reads for the SF-C-Maize, SF-C-Pinto, SF-R-Maize, SF-R Pinto, and a total of 35 and 36 million reads for the SL-Maize and SL-Pinto samples, respectively. After quality control measures, a total of 62.2 million reads from SL and 71.7 million reads from SF were used for transcriptome assembly (TA). The resulting final de novo reference TA (backbone) for the SF taxa contained 37,985 contigs with a N50 contig size of 1030 bp and a maximum contig length of 17,093 bp, while for SL, 28,329 contigs were generated with a N50 contig size of 1980 bp and a maximum contig length of 18,267 bp. The data presented herein contains supporting information related to our research article Roy et al. (2016) http://dx.doi.org/10.1016/j.ibmb.2016.02.006[1].