Assessment of the relationship between 25-hydroxyvitamin D and albuminuria in type 2 diabetes mellitus.

BACKGROUND: Diabetic nephropathy occurs in about one-third of diabetic patients. This health problem is characterized by increased urinary albumin excretion, leading to decreased glomerular filtration rate and renal failure. In this regard, previous investigations have revealed the possibility of a relationship between vitamin D deficiency and diabetic nephropathy. The present study assessed the relationship between vitamin D deficiency and albuminuria in patients with type 2 diabetes. METHODS: This study was conducted with 200 participants with type 2 diabetes mellitus from December 2019 to January 2021. The patients' 25-hydroxyvitamin D (25OHD) serum level and urinary albumin-to-creatinine ratio (UACR) were measured concurrently. Afterward, the subjects were divided into three groups based on their albuminuria level. Finally, 25OHD serum level and other clinical characteristics were compared among these albuminuria groups, and the relation between albuminuria level and 25OHD was analyzed. RESULTS: The prevalence of vitamin D deficiency in macroalbuminuric patients (UACR≥300 mg/g) was 61.8%, and in microalbuminuric (30 ≤ UACR< 300 mg/g) and normoalbuminuric groups (UACR< 30 mg/g) was 33.3% and 24%, respectively. Further analysis revealed a significant negative relationship between 25OHD and albuminuria(r = - 0.257, p-value< 0.001). According to ROC curve analysis, a 25OHD level ≤ 21 ng/ml was considered an optimal cut-off point value for having macroalbuminuria in diabetic patients. CONCLUSIONS: The current study evaluates the relation between vitamin D deficiency and the prevalence of albuminuria in the setting of diabetes. Overall, the prevalence of macroalbuminuria increased when the 25OHD serum level was less than 20 ng/ml.

A novel combined method for cost-benefit production of DNA ladders.

BACKGROUND: Molecular deoxyribonucleic acid markers are one of the most important tools in molecular biology labs. The size of DNA molecule is determined by comparing them with known bands of markers during gel electrophoresis. In this study, we have suggested an efficient strategy to produce molecular weight markers in an industrial scale. MATERIALS AND METHODS: A combination of two previously known methods, restriction enzyme digestion and polymerase chain reaction (PCR), was used. The enzymatic digestion process was based on designing and constructing plasmids which equaled in size with the bands of ladder and produce the DNA fragment by plasmid linearization through digestion. In the PCR method, the DNA fragments with length 102 bp lesser than the related bands in DNA ladder are amplified by PCR and cloned in pTZ57T/A cloning vector. Then, PCRs with forward and reverse 100-bp primers on the resulting plasmids amplify the ladder fragments. F100 and R100 primers bind to the backbone of pTZ57R (without insert) and amplify a 100-bp PCR product. PCR on the plasmid with insert amplifies DNA fragment with 102+ insert length bp size. RESULTS: Upon application of this strategy, 2000-10,000 bp DNA fragments were produced by enzymatic digestion of plasmids of the same size. Moreover, 100-1500 bp fragments were produced during PCR using only a set of forward and reverse (100 bp) primers. CONCLUSION: The highest advantage of this cost-benefit approach is to produce different types of molecular weight markers by using an effective and short protocol.