Category: Statistics

Metabolomics. 2021 Apr 23;17(5):44. doi: 10.1007/s11306-021-01795-2.

ABSTRACT

INTRODUCTION: Manganese is important for the endocarditis pathogen Streptococcus sanguinis. Little is known about why manganese is required for virulence or how it impacts the metabolome of streptococci.

OBJECTIVES: We applied untargeted metabolomics to cells and media to understand temporal changes resulting from manganese depletion.

METHODS: EDTA was added to a S. sanguinis manganese-transporter mutant in aerobic fermentor conditions. Cell and media samples were collected pre- and post-EDTA treatment. Metabolomics data were generated using positive and negative modes of data acquisition on an LC-MS/MS system. Data were subjected to statistical processing using MetaboAnalyst and time-course analysis using Short Time series Expression Miner (STEM). Recombinant enzymes were assayed for metal dependence.

RESULTS: We observed quantitative changes in 534 and 422 metabolites in cells and media, respectively, after EDTA addition. The 173 cellular metabolites identified as significantly different indicated enrichment of purine and pyrimidine metabolism. Further multivariate analysis revealed that the top 15 cellular metabolites belonged primarily to lipids and redox metabolites. The STEM analysis revealed global changes in cells and media in comparable metabolic pathways. Glycolytic intermediates such as fructose-1,6-bisphosphate increased, suggesting that enzymes that utilize them require manganese for activity or expression. Recombinant enzymes were confirmed to utilize manganese in vitro. Nucleosides accumulated, possibly due to a blockage in conversion to nucleobases resulting from manganese-dependent regulation.

CONCLUSION: Differential analysis of metabolites revealed the activation of a number of metabolic pathways in response to manganese depletion, many of which are connected to carbon catabolite repression.

PMID:33893555 | DOI:10.1007/s11306-021-01795-2

Clin Oral Investig. 2021 Apr 24. doi: 10.1007/s00784-021-03949-x. Online ahead of print.

ABSTRACT

OBJECTIVE: Treatment of implants with peri-implantitis is often unsuccessful due to residual microbial biofilm hindering re-osseointegration. The aim of this study was to treat biofilm-grown titanium (Ti) implants with different modalities involving air abrasion (AA) and cold atmospheric plasma (CAP) to compare the effectiveness in surface decontamination and the alteration/preservation of surface topography.

MATERIALS AND METHODS: Saliva collected from a peri-implantitis patient was used to in vitro develop human biofilm over 35 implants with moderately rough surface. The implants were then mounted onto standardized acrylic blocks simulating peri-implantitis defects and treated with AA (erythritol powder), CAP in a liquid medium, or a combination (COM) of both modalities. The remaining biofilm was measured by crystal violet (CV). Surface features and roughness before and after treatment were assessed by scanning electron microscope (SEM). The data were statistically analyzed using Kruskal-Wallis followed by Tukey’s multiple comparison test.

RESULTS: In the present peri-implantitis model, the human complex biofilm growth was successful as indicated by the statistical significance between the negative and positive controls. All the treatment groups resulted in a remarkable implant surface decontamination, with values very close to the negative control for AA and COM. Indeed, statistically significant differences in the comparison between the positive control vs. all the treatment groups were found. SEM analysis showed no post-treatment alterations on the implant surface in all the groups.

CONCLUSIONS: Decontamination with AA delivering erythritol with or without CAP in liquid medium demonstrated compelling efficacy in the removal of biofilm from implants. All the tested treatments did not cause qualitative alterations to the Ti surface features. No specific effects of the CAP were observed, although further studies are necessary to assess its potential as monotherapy with different settings or in combination with other decontamination procedures.

CLINICAL RELEVANCE: CAP is a promising option in the treatment of peri-implantitis because it has potential to improve the elimination of bacterial plaque from implant surfaces, in inaccessible pockets or during open-flap debridement, and should stimulate the process of the re-osseointegration of affected dental implants by not altering surface features and roughness.

PMID:33893556 | DOI:10.1007/s00784-021-03949-x

Biomech Model Mechanobiol. 2021 Apr 23. doi: 10.1007/s10237-021-01456-2. Online ahead of print.

ABSTRACT

The phenomenological model for cell shape deformation and cell migration Chen (BMM 17:1429-1450, 2018), Vermolen and Gefen (BMM 12:301-323, 2012), is extended with the incorporation of cell traction forces and the evolution of cell equilibrium shapes as a result of cell differentiation. Plastic deformations of the extracellular matrix are modelled using morphoelasticity theory. The resulting partial differential differential equations are solved by the use of the finite element method. The paper treats various biological scenarios that entail cell migration and cell shape evolution. The experimental observations in Mak et al. (LC 13:340-348, 2013), where transmigration of cancer cells through narrow apertures is studied, are reproduced using a Monte Carlo framework.

PMID:33893558 | DOI:10.1007/s10237-021-01456-2

Microb Ecol. 2021 Apr 23. doi: 10.1007/s00248-021-01759-y. Online ahead of print.

ABSTRACT

The extraction of commercial minerals is often accompanied by the formation of large areas of quarry and dump technogenic ecosystems. This stimulates the search for measures to reduce their negative impact on the environment, as well as a detailed study of all the constituent elements of ecosystems that spontaneously or after reclamation form on them. Primary stages of syngenesis on the tailing dumps of iron ore mines in Kryvorizhzhia took place involving cyanobacteria and eukaryotic algae. The dynamics of the community structures of algae and cyanobacteria depends on the mineralogical composition of tailings, salinity conditions, pH, and content of particles of physical clay and humus. The assessment of the features of the dynamics of algae communities was carried out based on the ordination procedure because of the method of non-metric multidimensional scaling. The considered environmental variables were statistically significant predictors of community structure and could explain 47-90% of the variation in measurements. Diagnostic signs of the species composition of communities of algae and cyanobacteria tailing dumps were established by physical and chemical parameters. An increase in the content of physical clay particles in the substrate and a pH shift towards the alkaline side increased the species richness of cyanobacteria, while an increase in the humus content increased the total species diversity. Based on the specificity of the type of growth and the species composition of algae communities, when describing the primary successions, it is proposed to allocate the following stages of development of algae and cyanobacteria communities: dispersal aerophyton, stratose epilitophyton, algal crust, mixed moss and algal crust, and edaphone.

PMID:33893532 | DOI:10.1007/s00248-021-01759-y

Surg Endosc. 2021 Apr 23. doi: 10.1007/s00464-021-08466-2. Online ahead of print.

ABSTRACT

OBJECTIVE: To evaluate the outcome following the strategy of endoscopic R0 resection (ER) plus adjuvant treatment (AT) versus esophagectomy for esophageal squamous cell cancer in T1a invading muscularis mucosa (M3)-T1b stage.

METHODS: We evaluated the outcomes of 46 esophageal squamous cell cancer (ESCC) patients with T1aM3-T1b stage who underwent ER + AT from the Esophageal Cancer Endoscopic Therapy Consortium (ECETC) and compared these outcomes to 92 patients who underwent esophagectomy. Propensity score matching (1:2) was used, with overall survival (OS) and relapse-free survival (RFS) being compared between the two groups.

RESULTS: During a median follow-up of 32 months, there were no statistical differences (P = 0.226) in OS between the two groups. The 1-, 2-, and 3-year overall survival in the esophagectomy group was 95%, 91%, and 84%, respectively. There were no mortalities within three years in the ER + AT group. The RFS between the two groups was also not significantly different (P = 0.938). The 1-, 2-, and 3-year RFS of patients in the esophagectomy group was 90%, 90%, and 83%, respectively, while it was 97%, 94%, and 74% in the ER + AT group, respectively. The local recurrence rates between the two groups were not significantly different (P = 0.277).

CONCLUSIONS: This first multicenter analysis showed similar outcomes were found regarding OS and RFS between the two groups in T1aM3-T1b stage patients. ER + AT may be considered in high-risk patients or for those who refuse esophagectomy.

PMID:33893544 | DOI:10.1007/s00464-021-08466-2

Parasitol Res. 2021 Apr 24. doi: 10.1007/s00436-021-07147-2. Online ahead of print.

ABSTRACT

Culicoides biting midges are small dipterous insects (Diptera: Ceratopogonidae) which are known to be vectors of arboviruses, bacteria, protozoan and helminth parasites that can cause disease and mortality in livestock and poultry globally. Detailed knowledge of the Culicoides species composition and biology is essential to assess the risk of the introduction and transmission of pathogens. The aim of this study was to obtain data on Culicoides species composition and flying activity in southeastern Lithuania and to determine the meteorological variables related to the abundance of Culicoides biting midges. Biting midges were collected in Verkiai Regional Park, southeastern Lithuania, using an Onderstepoort trap once a week from April to October 2016 and 2018, and from April to July 2019; 7332 Culicoides females belonging to 22 species were identified. Both morphology and DNA barcoding were used for identification. The number of specimens trapped was highest for the Obsoletus Group, followed by Culicoides kibunensis and Culicoides impunctatus. The highest relative abundance and diversity of biting midges were found in May and June. The number of trapped biting midges correlated positively with the mean air temperature. The first biting midges in spring were caught when the mean daily temperature rose higher than 10 °C. No Culicoides were detected when the air temperature dropped below 5 °C in autumn. Wind speed and air humidity had no statistically significant effect on Culicoides abundance.

PMID:33893548 | DOI:10.1007/s00436-021-07147-2

J Orofac Orthop. 2021 Apr 23. doi: 10.1007/s00056-021-00295-1. Online ahead of print.

ABSTRACT

PURPOSE: The aim of this randomized prospective clinical study was to determine whether there are differences between customized lingual brackets and conventional labial brackets regarding the alignment of the mandibular arch and a reduction of the irregularity index during an 18-week treatment interval.

METHODS: A total of 20 patients who presented with class I malocclusion for scheduled orthodontic treatment without tooth extraction were included. The patients were randomly assigned by numbered, opaque, sealed envelopes to treatment with customized lingual brackets or conventional labial brackets. During the initial alignment (T0), 0.012″ (T1), 0.014″ (T2), and 0.016″ (T3) nickel-titanium archwires were applied, respectively, and the control visits were scheduled at 6‑week intervals. In all sessions, digital models were obtained by an intraoral scanning device after removal of the archwire and were analyzed by software. Little’s irregularity index, intercanine width, intermolar width and arch length were evaluated at three time points and were statistically analyzed with a repeated measures analysis of variance (ANOVA). Changes in these measurements at the three intervals (T1-T0, T2-T1, T3-T2) and overall treatment effects were also compared using the Student t‑test.

RESULTS: Comparing the two treatments regimes, intergroup mean values at T0, T1, T2, and T3 were not significantly different regarding the irregularity index, intercanine width, intermolar width and arch length.

CONCLUSION: In this pilot study, no differences between the two treatment approaches could be detected for the phase of initial mandibular alignment.

PMID:33893516 | DOI:10.1007/s00056-021-00295-1

Arch Dermatol Res. 2021 Apr 23. doi: 10.1007/s00403-021-02233-y. Online ahead of print.

ABSTRACT

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic, inflammatory skin condition that substantially reduces patient quality of life. Many HS patients ask their dermatologist about potential lifestyle modifications, such as following particular diets or avoiding specific products, in an attempt to alleviate their symptoms. However, insufficient research has been conducted to support well-informed lifestyle modification counseling, and patients frequently defer to anecdotal endorsements of various interventions found on social media support groups. Therefore, we sought to clarify what lifestyle modifications were capable of improving HS symptoms.

METHODS: We conducted a survey-based study to examine modifiable risk factors and their association with the severity of HS. Five hundred and ninety-one patients with HS participated in an online survey detailing the severity of their HS symptoms before and after various lifestyle interventions. Average improvements in both subjective and objective ratings of symptom severity were calculated and statistical differences between the levels of improvement seen among various categories of lifestyle interventions were determined.

RESULTS: Numerous lifestyle interventions including substantial weight loss, smoking cessation, use of gentle skin and depilatory products, and menstrual regulation were associated with both subjective and objective improvements in symptom severity.

CONCLUSIONS: Our results suggest that patients affected by HS may experience clinically significant improvement from a variety of lifestyle modifications.

PMID:33893517 | DOI:10.1007/s00403-021-02233-y

Aesthetic Plast Surg. 2021 Apr 23. doi: 10.1007/s00266-021-02289-1. Online ahead of print.

ABSTRACT

BACKGROUND: Previous data were not conclusive on the safety of gestation in patients whose abdominal flaps were earlier harvested. We performed a meta-analysis to evaluate the abdominal wall complications and birth mode of pregnancy in post-TRAM or post-DIEP harvested individuals.

METHODS: A literature search was performed using the PubMed, Embase, Scopus, and Google scholar database. Heterogeneity was statistically analyzed, and random effect models were applied. Publication bias was assessed by funnel plot.

RESULTS: We included 25 papers that captured 56 patients giving birth to 69 healthy babies after elevation of abdominally based flaps, with a pooled abdominal complication rate of 0.00-0.09. The complication incidence in TRAM group was 0.01 (95% CI = [0.00-0.14%]) while 0.00 in the DIEP group (95% CI = [0.00-0.26%]). Discrepancies in incidence following unilaterally or bilaterally based TRAM flaps, following free or pedicled TRAM flaps, following primary sutured or mesh strengthened fascia, following MS free TRAM or conventional free TRAM could not be calculated as statistically significant. TRAM group and DIEP group patients had identical birth modes.

CONCLUSIONS: The present meta-analysis did not detect evidence that abdominal walls with the prior harvest of abdominal flaps could affect the process of pregnancy or contraindicate vaginal delivery. No abdominal hernia or bulge occurred with post-DIEP pregnancies. However, such conclusions need to be substantiated by larger sample studies.

LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine Ratings, please refer to Table of Contents or online Instructions to Authors www.springer.com/00266 .

PMID:33893518 | DOI:10.1007/s00266-021-02289-1

Dis Esophagus. 2021 Apr 24:doab021. doi: 10.1093/dote/doab021. Online ahead of print.

ABSTRACT

INTRODUCTION: The prognostic value of histomorphologic regression in primary esophageal cancer has been previously established, however the impact of lymph node (LN) response on survival still remains unclear. The aim of this review was to assess the prognostic significance of LN regression or downstaging following neoadjuvant therapy for esophageal cancer.

METHODS: An electronic search was performed to identify articles evaluating LN regression or downstaging after neoadjuvant therapy. Random effects meta-analyses were performed to assess the influence of regression in the LNs and nodal downstaging on overall survival. Histomorphologic tumor regression in LNs was defined by the absence of viable cells or degree of fibrosis on histopathologic examination. Downstaged LNs were defined as pN0 nodes by the tumor, node, and metastasis classification, which were positive prior to treatment neoadjuvant.

RESULTS: Eight articles were included, three of which assessed tumor regression (number of patients = 292) and five assessed downstaging (number of patients = 1368). Complete tumor regression (average rate of 29.1%) in the LNs was associated with improved survival, although not statistically significant (hazard ratio [HR] = 0.52, 95% confidence interval [CI] = 0.26-1.06; P = 0.17). LNs downstaging (average rate of 32.2%) was associated with improved survival compared to node positivity after neoadjuvant treatment (HR = 0.41, 95%CI = 0.22-0.77; P = 0.005).

DISCUSSION: The findings of this meta-analysis have shown a survival benefit in patients with LN downstaging and are suggestive for considering LN downstaging to ypN0 as an additional prognostic marker in staging and in the comparative evaluation of differing neoadjuvant regimens in clinical trials. No statistically significant effect of histopathologic regression in the LNs on long-term survival was seen.

PMID:33893494 | DOI:10.1093/dote/doab021