Glycation of nail proteins : from basic biochemical findings to a representative marker for diabetic glycation-associated target organ damage

Background : Although assessment of glycated nail proteins may be a useful marker for monitoring of diabetes, their nature and formation are still poorly understood. Besides a detailed anatomical analysis of keratin glycation, the usefulness of glycated nail protein assessment for monitoring diabetic complications was investigated. Methods : 216 patients (94 males, 122 females; mean age +/- standard deviation: 75.0 +/- 8.7 years) were enrolled. Glycation of nail and eye lens proteins was assessed using a photometric nitroblue tetrazolium-based assay. Following chromatographic separation of extracted nail proteins, binding and nonbinding fractions were analyzed using one-dimensional gel electrophoresis. Using a hand piece containing a latch-type-bur, a meticulous cutting of the nail plate into superficial and deep layers was performed, followed by a differential analysis of fructosamine. Results : Using SDS PAGE, four and two bands were identified among the nonglycated and glycated nail fraction respectively. Significantly lower fructosamine concentrations were found in the superficial nail layer (mean: 2.16 +/- 1.37 mu mol/g nails) in comparison with the deep layer (mean: 4.36 +/- 2.55 mu mol/g nails) (P<0.05). A significant higher amount of glycated eye lens proteins was found in diabetes mellitus patients (mean: 3.80 +/- 1.57 mu mol/g eye lens) in comparison with nondiabetics (mean: 3.35 +/- 1.34 mu mol/g eye lens) (P<0.05). A marked correlation was found between glycated nail and glycated eye lens proteins [y (glycated nail proteins) = 0.39 + 0.99 x (eye lens glycated proteins); r(2) = 0.58, P<0.001]. The concentration of glycated eye lens proteins and the HbA1c level were found to be predictors of the concentration of glycated nail proteins. Conclusions : Glycation of nail proteins takes place in the deep layer of finger nails, which is in close contact with blood vessels and interstitial fluid. Glycation of nail proteins can be regarded as a representative marker for diabetic glycation-associated target organ damage

Animal source food eating habits of outpatients with antimicrobial resistance in Bukavu, D.R. Congo

Background!#!Antibiotic resistance is a public health concern in Democratic Republic Congo and worldwide. It is usually caused by antibiotic over prescription or dispensing practices. The consumption of animal source food (ASF) could be another source of antibiotic resistance but is rarely studied. The objective of the study was to evaluate the eating habits of ASF by outpatients with antimicrobial resistance through an analysis of (i) the association of their antimicrobial resistance with ASF consumption; (ii) the influence of the types of ASF on their antimicrobial resistance.!##!Methods!#!This is a retrospective analytical study conducted at three major Hospitals in Bukavu City (D. R. Congo). A total number of 210 patients, whose samples (mainly faeces and urine) had been subjected to bacterial examination, was included in this study. Morphological, biochemical and antibiotic susceptibility (using disc diffusion method) tests were performed on the samples. This served to isolate and identify resistant bacteria. Afterwards, patients responded to questions about the types and quantity of ASF eaten in the last week. We analysed data using descriptive statistics, logistic regression and non-parametric ranking tests.!##!Results!#!Escherichia coli (37.1%), Klebsiella pneumonae (14.7%), and Staphylococcus aureus (13.8%) were the most prevalent bacteria. E. coli (68.4%) and K. pneumonae (87.5%) were multidrug resistant (MDR), while S. aureus (7.7%) was minor. Low beef (O.R. 0.737, C.I. 0.542-1.002) and pork (O.R. 0.743, C.I. 0.560 - 0.985) consumption led to significantly (p &amp;lt; 0.05) lower risks of resistance to ciprofloxacin. Patients eating three different ASF per week had the highest resistance score (20.67) and high consumption rates of goat meat, pork and milk (41.5%).!##!Conclusion!#!The findings of this study suggest a contribution of human nutrition to antimicrobial resistance frequency. Our results show the existence of a high prevalence of multi-drug resistant bacteria in patients for which eating beef, pork and drinking milk are major risk factors. Therefore, a stricter control of antibiotic usage in livestock production and of their presence in ASF is recommended

The presence of fructosamine in human aortic valves is associated with valve stiffness

AIMS: Human heart valves are prone to glycation, a fundamental process of ageing. The aim of this study was to establish the relationship between fructosamine formation and the mechanical properties of human aortic valves. METHODS: 67 patients (age: 76±8 years) diagnosed with an aortic valve stenosis, who underwent an aortic valve replacement were enrolled. Fructosamine and calcium concentrations in aortic valves were determined. Using a transthoracic Doppler echocardiography, aortic valve orifice area and transvalvular pressure gradients were measured. In a subgroup of 32 patients, the aortic valve orifice area was sufficient to carry out mechanical testing on a LFPlus Universal material tester. An in vitro removal of fructosamine of the valve was initiated using ATP-dependent fructosamine 3-kinase (FN3K). RESULTS: A significant correlation was found between the aortic valve fructosamine concentration and the calculated aortic valve orifice area: Y (aortic valve orifice area, mm2)=1.050-0.228X (aortic valve fructosamine concentration, µmol/g valve) (r=-0.38). A significantly higher calcium concentration was measured in the aortic valves of diabetics in comparison with those of non-diabetics. A multiple regression analysis revealed that the presence of diabetes mellitus and aortic valve fructosamine concentration were the main predictors of the extensibility of the aortic valves. In the in vitro deglycation study, a significant lower aortic valve fructosamine concentration was detected after treatment with FN3K. This resulted in an increased flexibility of the aortic valves. CONCLUSIONS: Although no direct causativeness is proven with the presented results, which just show an association between fructosamine, the effect of FN3K and aortic valve stiffness, the present study points for the first time towards a possible additional role of the Amadori products in the biomechanical properties of ageing aortic valves

Glycated nail proteins : a new approach for detecting diabetes in developing countries

Objective: To assess glycation of nail proteins as a tool in the diagnosis of diabetes. Methods: Glycation of nail proteins was assessed using a modified photometric nitroblue tetrazolium-based assay, which provides information about average glucose values of the last 6-9months. Analysis is possible on 10mg of nail clippings with a within-run coefficient of variation (CV) of 11%. The analyte is extremely stable. The reference range for glycated nail protein (0.55-3.60mol/g nail) increases upon ageing. Results: In diabetics (n=112), values for glycated nail protein are significantly higher (median: 4.07mol/g nail, IQR: 2.37-6.89mol/g nail, P<0.0001) than in non-diabetics (n=116). ROC analysis shows an AUC of 0.848 (specificity 93.1%; sensitivity 68.9%). Conclusion: This affordable method is a simple alternative for diagnosing diabetes in remote areas as the pre-analytical phase (including all processes from the time a laboratory request is made by a physician until the sample is ready for testing) is extremely robust

Glycated nail protein concentration between deep and superficial layers of the human finger nail (n = 12).

<p>Glycated nail protein concentration between deep and superficial layers of the human finger nail (n = 12).</p

Multiple regression model with glycated nail proteins as dependent variable.

<p>Multiple regression model with glycated nail proteins as dependent variable.</p

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of nail proteins after boronate affinity chromatography (extracted keratins with different molecular mass, ranging from 46 to 67 kDa).

<p>Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of nail proteins after boronate affinity chromatography (extracted keratins with different molecular mass, ranging from 46 to 67 kDa).</p

Correlation between glycated nail proteins and glycated eye lens proteins in the group of diabetes patients (n = 35).

<p>The equation of linear regression is y (glycated nail proteins) = 0.26 + 1.12 x (glycated eye lens proteins) (r2 = 0.71; P<0.001).</p