Corneal Collagen Cross-Linking for the Management of Mycotic Keratitis

Purpose

To evaluate the efficiency of corneal collagen cross-linking (CXL) in addition to topical voriconazole in cases with mycotic keratitis.

Design

Retrospective case series in a tertiary university hospital.

Participants

CXL was performed on 13 patients with mycotic keratitis who presented poor or no response to topical voriconazole treatment.

Methods

The clinical features, symptoms, treatment results and complications were recorded retrospectively. The corneal infection was graded according to the depth of infection into the stroma (from grade 1 to grade 3). The visual analogue scale was used to calculate the pain score before and 2 days after surgery.

Main Outcome Measures

Grade of the corneal infection.

Results

Mean age of 13 patients (6 female and 7 male) was 42.4 ± 17.7 years (20–74 years). Fungus was demonstrated in culture (eight patients) or cytological examination (five patients). Seven of the 13 patients (54%) were healed with topical voriconazole and CXL adjuvant treatment in 26 ± 10 days (15–40 days). The remaining six patients did not respond to CXL treatment; they initially presented with higher grade ulcers. Pre- and post-operative pain score values were 8 ± 0.8 and 3.5 ± 1, respectively (p < 0.05).

Conclusions

The current study suggests that adjunctive CXL treatment is effective in patients with small and superficial mycotic ulcers. These observations require further research by large randomized clinical trials.

     

Optimization of fecal sample preparation for untargeted LC-HRMS based metabolomics

Introduction

Collecting feces is easy. It offers direct outcome to endogenous and microbial metabolites.

Objectives

In a context of lack of consensus about fecal sample preparation, especially in animal species, we developed a robust protocol allowing untargeted LC-HRMS fingerprinting.

Methods

The conditions of extraction (quantity, preparation, solvents, dilutions) were investigated in bovine feces.

Results

A rapid and simple protocol involving feces extraction with methanol (1/3, M/V) followed by centrifugation and a step filtration (10 kDa) was developed.

Conclusion

The workflow generated repeatable and informative fingerprints for robust metabolome characterization.

     

Minimal variation of the plasma lipidome after delayed processing of neonatal cord blood

Background

Cord blood lipids are potential disease biomarkers. We aimed to determine if their concentrations were affected by delayed blood processing.

Method

Refrigerated cord blood from six healthy newborns was centrifuged every 12 h for 4 days. Plasma lipids were analysed by liquid chromatography/mass spectroscopy.

Results

Of 262 lipids identified, only eight varied significantly over time. These comprised three dihexosylceramides, two phosphatidylserines and two phosphatidylethanolamines whose relative concentrations increased and one sphingomyelin that decreased.

Conclusion

Delay in separation of plasma from refrigerated cord blood has minimal effect overall on the plasma lipidome.

     

Does centrifugation matter? Centrifugal force and spinning time alter the plasma metabolome

Background

Centrifugation is an indispensable procedure for plasma sample preparation, but applied conditions can vary between labs.

Aim

Determine whether routinely used plasma centrifugation protocols (1500×g 10 min; 3000×g 5 min) influence non-targeted metabolomic analyses.

Methods

Nuclear magnetic resonance spectroscopy (NMR) and High Resolution Mass Spectrometry (HRMS) data were evaluated with sparse partial least squares discriminant analyses and compared with cell count measurements.

Results

Besides significant differences in platelet count, we identified substantial alterations in NMR and HRMS data related to the different centrifugation protocols.

Conclusion

Already minor differences in plasma centrifugation can significantly influence metabolomic patterns and potentially bias metabolomics studies.

     

Clinical and radiologic rebound after discontinuation of natalizumab therapy in a highly active multiple sclerosis patient was not halted by dimethyl-fumarate: a case report

Background

The evidence on the use of the oral dimethyl-fumarate after the discontinuation of treatment with natalizumab in people with Multiple Sclerosis is still little. Natalizumab discontinuation may induce the recurrence or rebound of the clinical and neuroradiological disease activity. Currently no therapeutic approach has been established to abolish disease reactivation and rebound after natalizumab interruption.

Case Presentation

We describe a case of a 21-year-old woman affected from a highly active relapsing-remitting Multiple Sclerosis who developed a clinical and radiological rebound 5 months after the last infusion of natalizumab, while she was being treated with dimethyl-fumarate 240 mg twice daily. She had received a bridge “therapy” with Cyclophosphamide before staring dimethyl-fumarate.

Conclusion

We report on this case to stimulate further research to establish whether new current and future drugs available for multiple sclerosis are able to halt the disease rebound after the natalizumab interruption.

     

R-wave synchronised atrial pacing in pediatric patients with postoperative junctional ectopic tachycardia: the atrioventricular interval investigated by computational analysis and clinical evaluation

Background

R-wave synchronised atrial pacing is an effective temporary pacing therapy in infants with postoperative junctional ectopic tachycardia. In the technique currently used, adverse short or long intervals between atrial pacing and ventricular sensing (AP–VS) may be observed during routine clinical practice.

Objectives

The aim of the study was to analyse outcomes of R-wave synchronised atrial pacing and the relationship between maximum tracking rates and AP–VS intervals.

Methods

Calculated AP–VS intervals were compared with those predicted by experienced pediatric cardiologist.

Results

A maximum tracking rate (MTR) set 10 bpm higher than the heart rate (HR) may result in undesirable short AP–VS intervals (minimum 83 ms). A MTR set 20 bpm above the HR is the hemodynamically better choice (minimum 96 ms). Effects of either setting on the AP–VS interval could not be predicted by experienced observers. In our newly proposed technique the AP–VS interval approaches 95 ms for HR > 210 bpm and 130 ms for HR < 130 bpm. The progression is linear and decreases strictly (? 0.4 ms/bpm) between the two extreme levels.

Conclusions

Adjusting the AP–VS interval in the currently used technique is complex and may imply unfavorable pacemaker settings. A new pacemaker design is advisable to allow direct control of the AP–VS interval.

     

Insulin induces a shift in lipid and primary carbon metabolites in a model of fasting-induced insulin resistance

Introduction

Prolonged fasting in northern elephant seals (NES) is characterized by a reliance on lipid metabolism, conservation of protein, and reduced plasma insulin. During early fasting, glucose infusion previously reduced plasma free fatty acids (FFA); however, during late-fasting, it induced an atypical elevation in FFA despite comparable increases in insulin during both periods suggestive of a dynamic shift in tissue responsiveness to glucose-stimulated insulin secretion.

Objective

To better assess the contribution of insulin to this fasting-associated shift in substrate metabolism.

Methods

We compared the responses of plasma metabolites (amino acids (AA), FFA, endocannabinoids (EC), and primary carbon metabolites (PCM)) to an insulin infusion (65 mU/kg) in early- and late-fasted NES pups (n?=?5/group). Plasma samples were collected prior to infusion (T0) and at 10, 30, 60, and 120 min post-infusion, and underwent untargeted and targeted metabolomics analyses utilizing a variety of GC-MS and LC-MS technologies.

Results

In early fasting, the majority (72%) of metabolite trajectories return to baseline levels within 2 h, but not in late fasting indicative of an increase in tissue sensitivity to insulin. In late-fasting, increases in FFA and ketone pools, coupled with decreases in AA and PCM, indicate a shift toward lipolysis, beta-oxidation, ketone metabolism, and decreased protein catabolism. Conversely, insulin increased PCM AUC in late fasting suggesting that gluconeogenic pathways are activated. Insulin also decreased FFA AUC between early and late fasting suggesting that insulin suppresses triglyceride hydrolysis.

Conclusion

Naturally adapted tolerance to prolonged fasting in these mammals is likely accomplished by suppressing insulin levels and activity, providing novel insight on the evolution of insulin during a condition of temporary, reversible insulin resistance.

     

Characterisation of the main drivers of intra- and inter- breed variability in the plasma metabolome of dogs

Introduction

Dog breeds are a consequence of artificial selection for specific attributes. These closed genetic populations have metabolic and physiological characteristics that may be revealed by metabolomic analysis.

Objectives

To identify and characterise the drivers of metabolic differences in the fasted plasma metabolome and then determine metabolites differentiating breeds.

Methods

Fasted plasma samples were collected from dogs maintained under two environmental conditions (controlled and client-owned at home). The former (n = 33) consisted of three breeds (Labrador Retriever, Cocker Spaniel and Miniature Schnauzer) fed a single diet batch, the latter (n = 96), client-owned dogs consisted of 9 breeds (Beagle, Chihuahua, Cocker Spaniel, Dachshund, Golden Retriever, Greyhound, German Shepherd, Labrador Retriever and Maltese) consuming various diets under differing feeding regimens. Triplicate samples were taken from Beagle (n = 10) and Labrador Retriever (n = 9) over 3 months. Non-targeted metabolite fingerprinting was performed using flow infusion electrospray-ionization mass spectrometry which was coupled with multivariate data analysis. Metadata factors including age, gender, sexual status, weight, diet and breed were investigated.

Results

Breed differences were identified in the plasma metabolome of dogs housed in a controlled environment. Triplicate samples from two breeds identified intra-individual variability, yet breed separation was still observed. The main drivers of variance in dogs maintained in the home environment were associated with breed and gender. Furthermore, metabolite signals were identified that discriminated between Labrador Retriever and Cocker Spaniels in both environments.

Conclusion

Metabolite fingerprinting of plasma samples can be used to investigate breed differences in client-owned dogs, despite added variance of diet, sexual status and environment.

     

Dexamethasone downregulates SIRT1 and IL6 and upregulates EDN1 genes in stem cells derived from gingivae via the AGE/RAGE pathway

Objectives

To evaluate the effects of dexamethasone on the aging of mesenchymal stem cells from human gingiva using next-generation sequencing.

Results

Four mRNAs were upregulated and 12 were downregulated when the results of dexamethasone at 24 h were compared with the control at 24 h. Expressions of SIRT1 and IL6 were decreased in dexamethasone at 24 h but expression of EDN1 was increased.

Conclusions

Application of dexamethasone reduced the expression of SIRT1 and IL6 but enhanced the expression of EDN1 of stem cells.

     

Pranlukast,a novel binding ligand of human Raf1 kinase inhibitory protein

Objectives

To study the binding of pranlukast to hRKIP and its regulatory role in the Raf1/MEK/ERK signal pathway.

Results

NMR and fluorescence experiments demonstrated hRKIP could bind pranlukast with a binding constant of 1016 mM^?1. Residues (Y81, S109 and Y181) on the conserved ligand-binding pocket of hRKIP played a crucial role in binding pranlukast, and their mutations reduced the binding affinity more than 85 %. Furthermore, 25 μM pranlukast could up-regulate the ERK phosphorylation by about 17 %.

Conclusion

Pranlukast may be used as a potential drug precursor for treating hRKIP involved diseases.

     

Effect of food intake on myocardial performance index

Background

Myocardial performance index (MPI) has been investigated in a variety of populations, but the effect of food intake has not been evaluated. We assessed whether myocardial performance index is affected by food intake in healthy subjects.

Methods

Twenty-three healthy subjects aged 25.6?±?4.5 years were investigated. MPI was measured before, 30 min after, and 110 min after a standardized meal.

Results

MPI decreased significantly (P?<?0.05) from fasting values 30 min after the meal, and had almost returned to baseline after 110 min. MPI decreased from 0.28?±?0.06 (fasting) to 0.20?±?0.07 30 min after eating. At 110 min after eating the index value was almost back to the baseline value 0.26?±?0.06. (P?=?0.15).

Conclusions

This study shows that myocardial performance index is affected by food intake in healthy subjects.

     

Medical students and physical education students as CPR instructors: an appropriate solution to the CPR-instructor shortage in secondary schools?

Background

Integrating cardiopulmonary resuscitation (CPR) training in secondary schools will increase the number of potential CPR providers. However, currently too few certified instructors are available for this purpose. Training medical students and physical education student teachers to become CPR instructors could decrease this shortage.

Aim

Examine whether medical students and physical education student teachers can provide CPR training for secondary school pupils as well as (i.?e., non-inferior to) registered nurses.

Methods

A total of 144 secondary school pupils were randomly assigned to CPR training by a registered nurse (n = 12), a  medical student (n = 17) or a physical education student teacher (n = 15). CPR performance was assessed after training and after eight weeks in a simulated cardiac arrest scenario on a resuscitation manikin, using manikin software and video recordings.

Results

No significant differences were found between the groups on the overall Cardiff Test scores and the correctness of the CPR techniques during the post-training and retention test. All pupils showed sufficient CPR competence, even after eight weeks.

Conclusion

Training by medical students or physical education student teachers is non-inferior to training by a registered nurse, suggesting that school teachers, student teachers and medical students can be recruited for CPR training in secondary schools.

     

Comparison of strain parameters in dyssynchronous heart failure between speckle tracking echocardiography vendor systems

Background

Although mechanical dyssynchrony parameters derived by speckle tracking echocardiography (STE) may predict response to cardiac resynchronization therapy (CRT), comparability of parameters derived with different STE vendors is unknown.

Methods

In the MARC study, echocardiographic images of heart failure patients obtained before CRT implantation were prospectively analysed with vendor specific STE software (GE EchoPac and Philips QLAB) and vendor-independent software (TomTec 2DCPA). Response was defined as change in left ventricular (LV) end-systolic volume between examination before and six-months after CRT implantation. Basic longitudinal strain and mechanical dyssynchrony parameters (septal to lateral wall delay (SL-delay), septal systolic rebound stretch (SRSsept), and systolic stretch index (SSI)) were obtained from either separate septal and lateral walls, or total LV apical four chamber. Septal strain patterns were categorized in three types. The coefficient of variation and intra-class correlation coefficient (ICC) were analysed. Dyssynchrony parameters were associated with CRT response using univariate regression analysis and C-statistics.

Results

Two-hundred eleven patients were analysed. GE-cohort (n = 123): age 68 years (interquartile range (IQR): 61–73), 67% male, QRS-duration 177 ms (IQR: 160–192), LV ejection fraction: 26 ± 7%. Philips-cohort (n = 88): age 67 years (IQR: 59–74), 60% male, QRS-duration: 179 ms (IQR: 166–193), LV ejection fraction: 27 ± 8. LV derived peak strain was comparable in the GE- (GE: -7.3 ± 3.1%, TomTec: ?6.4 ± 2.8%, ICC: 0.723) and Philips-cohort (Philips: ?7.7 ± 2.7%, TomTec: ?7.7 ± 3.3%, ICC: 0.749). SL-delay showed low ICC values (GE vs. TomTec: 0.078 and Philips vs. TomTec: 0.025). ICC’s of SRSsept and SSI were higher but only weak (GE vs. TomTec: SRSsept: 0.470, SSI: 0.467) (Philips vs. QLAB: SRSsept: 0.419, SSI: 0.421). Comparability of septal strain patterns was low (Cohen’s kappa, GE vs. TomTec: 0.221 and Philips vs. TomTec: 0.279). Septal strain patterns, SRSsept and SSI were associated with changes in LV end-systolic volume for all vendors. SRSsept and SSI had relative varying C-statistic values (range: 0.530–0.705) and different cut-off values between vendors.

Conclusions

Although global longitudinal strain analysis showed fair comparability, assessment of dyssynchrony parameters was vendor specific and not applicable outside the context of the implemented platform. While the standardization taskforce took an important step for global peak strain, further standardization of STE is still warranted.

     

Effecten van geriatrische COPD-revalidatie op ziekenhuisopnames en inspanningstolerantie: een retrospectief observationele studie

Introduction

Frail COPD patients are frequently not accepted for regular pulmonary rehabilitation programs due to low physical condition and functional limitations. Rehabilitation programs in nursing homes for geriatric patients with COPD have been developed. The effects of such programs are largely unknown.

Aims

To assess the course of COPD-related hospital admissions and exercise tolerance in a cohort of frail COPD patients participating in geriatric COPD rehabilitation.

Methods

Retrospective observational study with a follow up of 12 months after discharge from rehabilitation. COPD related hospital admission days were measured in the year before and after participating rehabilitation. Exercise tolerance was measured by the six minute walk test (6MWT) at admission and at discharge from rehabilitation.

Results

Fifty-eight participants accomplished the rehabilitation program. Twelve patients died in the first year after discharge. The median number of hospital admission days in the year before participating rehabilitation was 21 (IQR 10–33). The first year after discharge this was decreased to a median of 6 (IQR 0–12). The 6MWT increased from 194 (SD 85) meters at admission to 274 (SD 95) meters at discharge (mean difference 80 m, SD 72; p < 0.05).

Conclusions

Geriatric COPD rehabilitation in a nursing home setting seems to reduce hospital admissions in frail COPD patients and to increase exercise tolerance.

     

Transient expression of recombinant tissue plasminogen activator (rt-PA) gene in cucurbit plants using viral vector

Objective

To use a transient expression system to express a truncated human tissue plasminogen activator (K2S) gene in cucurbit plants.

Results

The recombinant tissue plasminogen activator protein (K2S form) was expressed in active form in cucurbit plants. Its molecular weight was 43 kDa. The plant-derived rt-PA was determined using goat anti-rabbit antibody by western blotting. Among the infected lines, the highest expression of rt-PA was 62 ng/100 mg per leaf tissue as measured by ELISA. The enzymatic activity of the plant-derived rt-PA was 0.8 IU/ml.

Conclusions

The K25 form of rt-PA was expressed for the first time using the viral expression system. Plant-derived rt-PA showed similar potency to commercially-available PA.

     

Daily variation and effect of dietary folate on urinary pteridines

Introduction

Urinary pteridines are putative molecular biomarkers for noninvasive cancer screening and prognostication. Central to their translational biomarker development is the need to understand the sources and extent of their non-epidemiological variation.

Objectives

This study was designed to characterize the two primary sources of urinary pteridine variance: daily variation and the effect of dietary folate.

Methods

Daily variation was studied by collecting urine specimens (n = 81) three times daily for 3 days. The effect of dietary folate was investigated in a treatment study in which urine specimens (n = 168) were collected daily during a control week and a treatment week during which participants received dietary folate supplements. Measurements of six urinary pteridines were made using high-performance liquid chromatography–tandem mass spectrometry. Coefficients of variation were calculated to characterize daily variance between and within subjects, while nearest neighbor non-parametric analyses were used to identify diurnal patterns and measure dietary folate effects.

Results

Daily variance was approximately 35 % RSD for both within-day and between-day periods for most pteridines. Diurnal patterns in response to circadian rhythms were similarly observed for urinary pteridines. Folate supplementation was shown to alter urinary pteridine profiles in a pathway dependent manner, suggesting that dietary folate may regulate endogenous neopterin and biopterin biosynthesis.

Conclusions

Urinary pteridine levels were found to be responsive to both daily variation and folate supplementation. These findings provide new insights into pteridine biosynthesis and regulation as well as useful information for the design of future clinical translational research.

     

Metabolomics profiling of concussion in adolescent male hockey players: a novel diagnostic method

Introduction

Concussions are a major health concern as they cause significant acute symptoms and in some athletes, long-term neurologic dysfunction. Diagnosis of concussion can be difficult, as are the decisions to stop play.

Objective

To determine if concussions in adolescent male hockey players could be diagnosed using plasma metabolomics profiling.

Methods

Plasma was obtained from 12 concussed and 17 non-concussed athletes, and assayed for 174 metabolites with proton nuclear magnetic resonance and direct injection liquid chromatography tandem mass spectrometry. Data were analysed with multivariate statistical analysis and machine learning.

Results

The estimated time from concussion occurrence to blood draw at the first clinic visit was 2.3 ± 0.7 days. Using principal component analysis, the leading 10 components, each containing 9 metabolites, were shown to account for 82 % of the variance between cohorts, and relied heavily on changes in glycerophospholipids. Cross-validation of the classifier using a leave-one out approach demonstrated a 92 % accuracy rate in diagnosing a concussion (P < 0.0001). The number of metabolites required to achieve the 92 % diagnostic accuracy was minimized from 174 to as few as 17 metabolites. Receiver operating characteristic analyses generated an area under the curve of 0.91, indicating excellent concussion diagnostic potential.

Conclusion

Metabolomics profiling, together with multivariate statistical analysis and machine learning, identified concussed athletes with >90 % certainty. Metabolomics profiling represents a novel diagnostic method for concussion, and may be amenable to point-of-care testing.

     

Impact of transduction towards the proliferation and migration as well as the transduction efficiency of human umbilical cord-derived late endothelial progenitor cells with nine recombinant adeno-associated virus serotypes

Objectives

To evaluate the transduction efficiency of human umbilical cord-derived, late endothelial progenitor cells late (HUCB-late EPCs) with nine recombinant adeno-associated virus (rAAV) serotypes and the ability of proliferation and migration of the cells after transduction.

Results

rAAV2 and rAAV6 showed a greater ability than other serotypes to transduce late EPCs (P < 0.05). After transduction, cell proliferation ability weakened (P < 0.05), but the ability of migration to stromal cell-derived factor (SDF-1) unchanged.

Conclusion

There is an advantage of choosing the optimal rAAV serotype as a gene vector to alter the biologic characteristics of late EPCs.

     

Application of residual polysaccharide-degrading enzymes in dried shiitake mushrooms as an enzyme preparation in food processing

Objective

To examine the activities of residual enzymes in dried shiitake mushrooms, which are a traditional foodstuff in Japanese cuisine, for possible applications in food processing.

Results

Polysaccharide-degrading enzymes remained intact in dried shiitake mushrooms and the activities of amylase, β-glucosidase and pectinase were high. A potato digestion was tested using dried shiitake powder. The enzymes reacted with potato tuber specimens to solubilize sugars even under a heterogeneous solid-state condition and that their reaction modes were different at 38 and 50 °C.

Conclusion

Dried shiitake mushrooms have a potential use in food processing as an enzyme preparation.