Seven peptides derived from pro-somatostatin in rat brain

Acid extracts of murine hypothalamic and extra-hypothalamic rat brains were analyzed by specific radioimmunoassays for the presence of somatostatin-14, somatostatin-28 and somatostatin-28(1–12)-like immunoreactivity. Seven molecular forms were observed after gel permeation chromatography. In addition to somatostatin-14, somatostatin-28 and somatostatin-28(1–12), there were two peptides of 4,400 and 7,500 mol. wt. which contained the somatostatin-28(1–12) sequence with an extension towards the NH₂-terminus of pro-somatostatin. Moreover, two other peptides of 6,000 and 9,500 mol. wt. were detected containing the whole somatostatin-28 structure. These results imply that the processing of brain pro-somatostatin involves a minimum of four cleavage sites and yields at least seven peptides.     

Humoral (immunological) responses in female albino rats during rotating magnetic field exposures

Experiments were designed to evaluate the primary and secondary humoral responses to a rotating magnetic field configuration, which is known to evoke significant biobehavioral changes. Ten days after inoculation with human serum albumin and 10 days before a booster, female rats were exposed to eigher a 0.5 Hz rotating magnetic field (RMF) or to room conditions (control). The lighting schedule was either continuous or involved a light-dark cycle (LD) of 12:12h. A third group of rats served as colony room controls. Group differences of low statistical significance were found when females were exposed to continuous lighting rather than the LD 12:12 light-dark cycle. However, the effects were considered trivial and not sufficient to explain the previously reported biobehavioral changes evoked by this field configuration.     

DFT/B3LYP calculations,in vitro cytotoxicity and antioxidant activities of steroidal pyrimidines and their interaction with HSA using molecular docking and multispectroscopic techniques

As a part of our continuing program on the synthesis of steroidal heterocycles, it has been prepared a series of novel steroidal pyrimidine derivatives 4–6 via TMSCl, steroidal ketones (1c–3c), urea and benzaldehyde. The systems presented here, are novel scaffolds and have not been described before at 6th position of steroidal-6-one (1c–3c). Structural assignment of newly synthesized compounds was performed by DFT/B3LYP calculations as well as spectral and analytical data. The interactions of compounds (4–6) with HSA were studied by fluorescence spectroscopy, DLS, CD and molecular docking, under imitated physiological conditions. The antitumor activity has been tested in vitro against three cancer cell lines MDA-MB231 (breast carcinoma), HeLa (human cervical carcinoma), HepG2 (hepatic carcinoma) and one non-cancer normal cell lines, PBMCs (peripheral blood mononuclear cell) by MTT assay. In addition, in vitro antioxidant activity and apoptosis assay of the synthesized compounds (4–6) have also been investigated.     

Albuminuria,Disease Duration,and Glycated Hemoglobin Are Related With Bone Mineral Density in Type 1 Diabetes: A Cross-sectional Study

ObjectiveStudies have found a significant decrease in bone mineral density (BMD) in individuals with type 1 diabetes (T1D) compared to healthy controls. Factors associated with this phenomenon have yet to be defined; therefore, this study aimed to explore the association of glycated hemoglobin (HbA1c), disease duration, albuminuria, and glomerular filtration rate with BMD in adults with T1D.MethodsA cross-sectional study was carried out in tertiary care center. BMD analysis was performed by dual x-ray absorptiometry. Linear models were constructed considering variables associated with BMD. Approval from the ethics committees and informed consent were obtained.ResultsWe included 128 participants, of whom 59% were women, and 16% had menopause. The median age was 33 (26-42) years. The average age of diabetes diagnosis was 15.3 ± 6.3 years, and the median disease duration was 19.5 (12-27) years. In the adjusted analysis, higher albuminuria (P < .01) and disease duration (P < .05) were associated with a lower BMD in the femoral neck and total hip, independently of age, sex, and body mass index (BMI). Higher HbA1c (P < .01) was associated with a lower spine BMD after adjustment for age, sex, and BMI.ConclusionStudied factors specific to T1D, including albuminuria, disease duration, and HbA1c have an association with BMD regardless of BMI, age, and sex.     

A Clinical Prediction Model to Distinguish Maturity-Onset Diabetes of the Young From Type 1 and Type 2 Diabetes in the Chinese Population

ObjectiveGenetic detection for the diagnosis of maturity-onset diabetes of the young (MODY) in China has low sensitivity and specificity. Better gene detection is urgently needed to distinguish testing subjects. We proposed to use numerous and weighted clinical traits as key indicators for reasonable genetic testing to predict the probability of MODY in the Chinese population.MethodsWe created a prediction model based on data from 306 patients, including 140 patients with MODY, 84 patients with type 1 diabetes (T1D), and 82 patients with type 2 diabetes (T2D). This model was evaluated using receiver operating characteristic curves.ResultsCompared with patients with T1D, patients with MODY had higher C-peptide levels and negative antibodies, and most patients with MODY had a family history of diabetes. Different from T2D, MODY was characterized by lower body mass index and younger diagnostic age. A clinical prediction model was established to define the comprehensive probability of MODY by a weighted consolidation of the most distinguishing features, and the model showed excellent discrimination (areas under the curve of 0.916 in MODY vs T1D and 0.942 in MODY vs T2D). Further, high-sensitivity C-reactive protein, glycated hemoglobin A1c, 2-h postprandial glucose, and triglyceride were used as indicators for glucokinase-MODY, while triglyceride, high-sensitivity C-reactive protein, and hepatocellular adenoma were used as indicators for hepatocyte nuclear factor 1-α MODY.ConclusionWe developed a practical prediction model that could predict the probability of MODY and provide information to identify glucokinase-MODY and hepatocyte nuclear factor 1-α MODY. These results provide an advanced and more reasonable process to identify the most appropriate patients for genetic testing.     

Synteny mapping of human chromosome 8 loci in cattle

Four genes having homologous loci on the short arm of human chromosome 8 have been mapped to two different bovine syntenic groups. The gene coding for the tissue-type plasminogen activator mapped with GSR, a human chromosome 8 marker, of syntenic group U14 while lipoprotein lipase and the medium and light neurofilament polypeptide genes were shown to be syntenic with the human chromosome 9 marker GGTB2 of syntenic group U18.     

Correlation Between Hemoglobin Glycation Index Measured by Continuous Glucose Monitoring With Complications in Type 1 Diabetes

ObjectiveHbA1C is the “gold standard” parameter to evaluate glycemic control in diabetes; however, its correlation with mean glucose is not always perfect. The objective of this study was to correlate continuous glucose monitoring (CGM)-derived hemoglobin glycation index (HGI) with microvascular complications.MethodsWe conducted a cross-sectional study including permanent users of CGM with type 1 diabetes mellitus or latent autoimmune diabetes of the adult. HGI was estimated, and presence of microvascular complications was compared in subgroups with high or low HGI. A logistic regression analysis to assess the contribution of high HGI to chronic kidney disease (CKD) was performed.ResultsIn total, 52 participants who were aged 39.7 ± 14.7 years, with 73.1% women and 15.5 years (IQR, 7.5-29 years) since diagnosis, were included; 32.7% recorded diabetic retinopathy, 25% CKD, and 19.2% neuropathy. The median HbA1C was 7.6% (60 mmol/mol) and glucose management indicator (GMI) 7.0% (53 mmol/mol). The average HGI was 0.55% ± 0.66%. The measured HbA1C was higher in the group with high HGI (8.1% [65 mmol/mol] vs 6.9% [52 mmol/mol]; P < .001), whereas GMI (7.0% [53 mmol/mol] vs 7.0% [53 mmol/mol]; P = .495) and mean glucose were similar in both groups (153 mg/dL vs 153 mg/dL; P = .564). In the high HGI group, higher occurrence of CKD (P = .016) and neuropathy were observed (P = .025). High HGI was associated with increased risk of CKD (odds ratio [OR]: 5.05; 95% CI: 1.02-24.8; P = .04) after adjusting for time since diagnosis (OR: 1.09; 95% CI: 1.02-1.16; P = .008).ConclusionHigh HGI measured by CGM may be a useful marker for increased risk of microvascular diabetic complications.     

A Higher Serum Calcium Level is an Independent Risk Factor for Vision-Threatening Diabetic Retinopathy in Patients with Type 2 Diabetes: Cross-Sectional and Longitudinal Analyses

ObjectiveAn elevated serum calcium level is associated with a higher risk of type 2 diabetes (T2D), but its role in microvascular complications remains unclear. This study was conducted to investigate the association between serum calcium levels and vision-threatening diabetic retinopathy (VTDR).MethodsThis study employed a cross-sectional and longitudinal design. The cross-sectional part included all patients treated for T2D at Shanghai General Hospital between 2007 and 2016, while the longitudinal part involved an overlapping cohort of diabetic patients without VTDR who were followed from their admission until December 2019. Multivariable logistic and Cox proportional hazard regression analyses were performed, respectively. VTDR was defined as severe nonproliferative diabetic retinopathy, proliferative diabetic retinopathy, or clinically significant macular edema.ResultsA total of 3269 patients were included in the cross-sectional analysis, and 649 patients were included in the longitudinal analysis. In the cross-sectional analysis, higher corrected serum calcium (odds ratio: 1.31 per 0.1 mmol/L, 95% confidence interval: 1.16-1.49), younger age, longer diabetes duration, albuminuria, impaired renal function, and lower serum magnesium were independently associated with VTDR. In the longitudinal analysis, 95 subjects developed VTDR during follow-up (9.7 years, interquartile range: 7.4-10.9 years). Higher corrected serum calcium (hazard ratio: 1.38 per 0.1 mmol/L, 95% confidence interval: 1.10-1.72), younger age, longer diabetes duration, sub-VTDR, albuminuria, lower serum magnesium, and higher glycated hemoglobin were identified as independent risk factors for VTDR.ConclusionsA higher serum calcium level may be an independent risk factor for VTDR in patients with T2D.     

Elucidation of direct competition and allosteric modulation of small‐molecular‐weight protein ligands using surface plasmon resonance methods

The present work introduces a surface plasmon resonance‐based method for the discrimination of direct competition and allosteric effects that occur in ternary systems comprising a receptor protein and two small‐molecular‐weight ligands that bind to it. Fatty acid binding protein 4, fructose‐1,6‐bisphosphatase and human serum albumin were used as model receptor molecules to demonstrate the performance of the method. For each of the receptor molecules, pairs of ligand molecules were selected for which either direct competition or an allosteric effect had already been determined by other methods. The method of discrimination introduced here is based on the surface plasmon resonance responses observed at equilibrium when an immobilized receptor protein is brought into contact with binary mixtures of interacting ligands. These experimentally determined responses are compared with the responses calculated using a theoretical model that considers both direct competition and allosteric ligand interaction modes. This study demonstrates that the allosteric ternary complex model, which enables calculation of the fractional occupancy of the protein by each ligand in such ternary systems, is well suited for the theoretical calculation of these types of responses. For all of the ternary systems considered in this work, the experimental and calculated responses in the chosen concentration ratio range were identical within a five‐σ confidence interval when the calculations considered the correct interaction mode of the ligands (direct competition or different types of allosteric regulation), and in case of allosteric modulation, also the correct strength of this effect. This study also demonstrates that the allosteric ternary complex model‐based calculations are well suited to predict the ideal concentration ratio range or even single concentration ratios that can serve as hot spots for discrimination, and such hot spots can drastically reduce the numbers of measurements needed for discrimination between direct competition and distinct modulation modes (neutral, positive or negative allostery). Copyright © 2015 John Wiley & Sons, Ltd.     

Binding of estradiol to horseradish peroxidase and horse heart microperoxidase

Horseradish peroxidase and horse heart microperoxidase can bind estradiol to human or bovine serum albumin in the presence of hydrogen peroxide. However, we have shown here that, in the absence of serum albumin, the hormone was fixed by the enzyme molecule itself. Evidence is presented that (a) the hormone is transformed into a water-soluble and dialysable derivative of estradiol; (b) this new product is easily separated from the enzyme by gel filtration chromatography. It appears to have a high affinity for the chromatographic gel. The implications of the binding of an estradiol derivative to peroxidases are discussed.