Graded alterations of RBC aggregation influence in vivo blood flow resistance

Although the effects of red blood cell (RBC) aggregation on low-shear rate blood viscosity are well known, the effects on in vivo flow resistance are still not fully resolved. The present study was designed to explore the in vivo effects of RBC aggregation on flow resistance using a novel technique to enhance aggregation: cells are covalently coated with a block copolymer (Pluronic F-98) and then suspended in unaltered plasma. RBC aggregation was increased in graded steps by varying the Pluronic concentration during cell coating and was verified by microscopy and erythrocyte sedimentation rate (ESR), which increased by 200% at the highest Pluronic level. RBC suspensions were perfused through an isolated in situ guinea pig hindlimb preparation while the arterial perfusion pressure was held constant at 100 mmHg via a pressure servo-controlled pump. No significant effects of enhanced RBC aggregation were observed when studies were conducted in preparations with intact vascular control mechanisms. However, after inhibition of smooth muscle tone (using 10(-4) M papaverin), a significant change in flow resistance was observed in a RBC suspension with a 97% increase of ESR. Additional enhancements of RBC aggregation (i.e., 136 and 162% increases of ESR) decreased flow resistance almost to control values. This was followed by another significant increase in flow resistance during perfusion with RBC suspensions with a 200% increase of ESR. This triphasic effect of graded increases of RBC aggregation is most likely explained by an interplay of several hemodynamic mechanisms that are triggered by enhanced RBC aggregation.     

PROGRESS STUDY: Progression of chronic kidney disease in children and heat shock proteins

Various molecular and cellular processes are involved in renal fibrosis, such as oxidative stress, inflammation, endothelial cell injury, and apoptosis. Heat shock proteins (HSPs) are implicated in the progression of chronic kidney disease (CKD). Our aim was to evaluate changes in urine and serum HSP levels over time and their relationships with the clinical parameters of CKD in children. In total, 117 children with CKD and 56 healthy children were examined. The CKD group was followed up prospectively for 24 months. Serum and urine HSP27, HSP40, HSP47, HSP60, HSP70, HSP72, and HSP90 levels and serum anti-HSP60 and anti-HSP70 levels were measured by ELISA at baseline, 12 months, and 24 months. The urine levels of all HSPs and the serum levels of HSP40, HSP47, HSP60, HSP70, anti-HSP60, and anti-HSP70 were higher at baseline in the CKD group than in the control group. Over the months, serum HSP47 and HSP60 levels steadily decreased, whereas HSP90 and anti-HSP60 levels steadily increased. Urine HSP levels were elevated in children with CKD; however, with the exception of HSP90, they decreased over time. In conclusion, our study demonstrates that CKD progression is a complicated process that involves HSPs, but they do not predict CKD progression. The protective role of HSPs against CKD may weaken over time, and HSP90 may have a detrimental effect on the disease course.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12192-021-01239-9.     

A molecularly imprinted nanofilm‐based quartz crystal microbalance sensor for the real‐time detection of pirimicarb

This study aimed to prepare a novel quartz crystal microbalance (QCM) sensor for the detection of pirimicarb. Pirimicarb‐imprinted poly (ethylene glycol dimethacrylate‐N‐metacryloyl‐(l )‐tryptophan methyl ester) [p (EGDMA‐MATrp)] nanofilm (MIP) on the gold surface of a QCM chip was synthesized using the molecular imprinting technique. A nonimprinted p (EGDMA‐MATrp) nanofilm (NIP) was also synthesized using the same experimental technique. The MIP and NIP nanofilms were characterized via Fourier transform infrared spectroscopy attenuated total reflectance spectroscopy, contact angle, atomic force microscopy, and an ellipsometer. A competitive adsorption experiment on the sensor was performed to display the selectivity of the nanofilm. An analysis of the QCM sensor showed that the MIP nanofilm exhibited high sensitivity and selectivity for pirimicarb determination. A liquid chromatography‐tandem mass spectrometry method was prepared and validated to determine the accuracy and precision of the QCM sensor. The accuracy and precision of both methods were determined by a comparison of six replicates at three different concentrations to tomato samples extracted by using a Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method. The limit of detection of the QCM sensor was found to be 0.028 nM. In conclusion, the QCM sensor showed good accuracy, with recovery percentages between 91 and 94%. Also, the pirimicarb‐imprinted QCM sensor exhibited a fast response time, reusability, high selectivity and sensitivity, and a low limit of detection. Therefore, it offers a serious alternative to the traditional analytical methods for pesticide detection in both natural sources and aqueous solutions.     

Fryns syndrome with atypical findings--with large midline cleft on forehead but normal cranial MRI findings

We report a newborn with Fryns syndrome and atypical findings like a large midline cleft on forehead. Abnormal findings included congenital left diaphragmatic hernia, prominent forehead, hypertelorism, broad nasal bridge, anteverted nostrils, cleft palate, low set ears, tapered fingers, macrocephaly, congenital heart defect, midline defects and renal anomalies. This is the first case that has a midline cleft on forehead with normal cranial MRI findings.     

Renal aquaporins and sodium transporters with special focus on urinary tract obstruction

The discovery of aquaporin-1 (AQP1) by Agre and colleagues explained the long-standing biophysical question of how water specifically crosses biological membranes. These studies led to the discovery and identification of a whole new family of membrane proteins, the aquaporins. At present, at least seven aquaporins are expressed at distinct sites in the kidney and 4 members of this family (AQP1-4) have been demonstrated to play pivotal roles in the physiology and pathophysiology for renal regulation of body water balance. Osmotic equilibration via renal aquaporins is maintained by active transport of NaCl. The major sodium transporters and channels in the individual renal tubule segments have been identified and the regulation of these transporters and channels are fundamental for renal sodium reabsorption and for establishing the driving force. In this mini-review the role of renal aquaporins and sodium transporters and channels is briefly described and their key role for the impaired urinary concentrating capacity in response to urinary tract obstruction is reviewed. Thus this review updates previous detailed reviews (1-5).     

The determination of the relationship between p97/VCP,small VCP-interacting protein,two ERAD proteins and steroidogenesis in Leydig cell lines

Background

In recent studies, it was shown that Endoplasmic reticulum-associated degradation (ERAD) is regulated by androgens and small VCP-interacting protein (SVIP) is an ERAD inhibitor. There is no data available about the interactions of ERAD proteins with proteins involved in steroidogenesis. The aim of the study was to investigate the expressions of SVIP, p97/VCP, StAR, CYP17A1 and 3β-HSD in human and mouse.

Methods and results

HLC, TM3 and MA-10 Leydig cell lines were used to determine roles of ERAD proteins in steroidogenesis based on immunofluorescence, Western blot, qRT-PCR, ELISA. Findings showed that StAR, CYP17A1 and 3β-HSD were colocalized with SVIP and p97/VCP in Leydig cells. A decrease in CYP17A1, 3β-HSD and StAR expressions was observed as a result of suppression of SVIP siRNAs and p97/VCP siRNAs expressions in MA10, TM3 and HLC. When siSVIP transfected cells were compared with siSVIP transfected with hCG-exposed cells, SVIP protein expression was significantly increased as compared to the SVIP transfected group in human Leydig cells.

Conclusion

We suggest that the suppression of protein expressions by p97/VCP and SVIP siRNAs in Leydig cells, the effects of proteins involved in steroidogenesis (StAR, CYP17A1 and 3β-HSD) have proven to be originating from p97/VCP and SVIP which were playing a role in the steroidogenesis process. Additionally, it was demonstrated that testosterone levels decreased after transfection with p97/VCP siRNA and SVIP siRNA, p97/VCP and SVIP created an effect on testosterone synthesis while taking place in the steps of testosterone synthesis. Further, it was determined in the study that the SVIP was affected by hCG stimulations.

     

Paraoxonase and arylesterase levels in autoimmune thyroid diseases

Objective: The aim of this study was to evaluate serum paraoxonase-1 (PON1) activity and its association with oxidative stress in autoimmune thyroid disease (AITD).

Methods: A total of 50 patients with AITD, including 25 with Hashimoto's thyroiditis and 25 with Graves’ disease were enrolled. The control group comprised 27 healthy subjects. Blood samples were obtained in the euthyroid period and 3 months after initiation of medical treatment. Serum samples from patients with AITD and the healthy control group were analyzed for basal PON1, salt-stimulated PON1, and arylesterase (ARE) activities, along with lipid hydroperoxide (LOOH) and total free sulfhydryl (–SH) levels.

Results: Serum PON1 activities and –SH levels were significantly lower (P?<?0.001, for each), whereas LOOH levels were significantly higher (P?<?0.001, for each) in patients with AITD, compared to the control group. We observed no significant differences in ARE levels between the patient and healthy control groups (P?>?0.05). PON1 activity was positively correlated with –SH (r?=?0.522, P?<?0.001) and negatively correlated with LOOH (r?=??0.487, P?<?0.001). PON1 phenotype distribution of the subjects was not significantly different among the three groups (P?=?0.961).

Conclusions: Serum PON1 activity is decreased in patients with AITD, and correlated positively with –SH, a well-known antioxidant, and negatively with LOOH, an index of lipid oxidation.