Recent advances in freeze-fracture electron microscopy: the replica immunolabeling technique

Freeze-fracture electron microscopy is a technique for examining the ultrastructure of rapidly frozen biological samples by transmission electron microscopy. Of a range of approaches to freeze-fracture cytochemistry that have been developed and tried, the most successful is the technique termed freeze-fracture replica immunogold labeling (FRIL). In this technique, samples are frozen, fractured and replicated with platinum-carbon as in standard freeze fracture, and then carefully treated with sodium dodecylsulphate to remove all the biological material except a fine layer of molecules attached to the replica itself. Immunogold labeling of these molecules permits their distribution to be seen superimposed upon high resolution planar views of membrane structure. Examples of how this technique has contributed to our understanding of lipid droplet biogenesis and function are discussed

Формування індивідуального стилю у творчості народних майстрів художньої обробки дерева (на прикладі різьбярських династій Шкрібляків та Корпанюків)

У статті розглянуто творчість видатних різьбярських династій Шкрібляків та Корпанюків з позиції формування власного стилю в кожного з майстрів та їхнього впливу на зародження Косівської школи художньої обробки дерева. Особливу увагу приділено тим технічним і технологічним новаціям, які застосовували у своїх творах різьбярі, та тим композиційним прийомам, які вирізняли їхні вироби з-поміж інших.В статье рассматривается творчество выдающихся династий резчиков Шкрибляков и Корпанюков с точки зрения формирования собственного стиля у каждого из мастеров и их влияния на зарождение Косовской школы художественной обработки дерева. Особое внимание уделяется тем техническим и технологическим новациям, которые использовали резчики в своих произведениях, и композиционным приёмам, выделяющим их изделия среди прочих.There is an observation of creative work of the illustrious Shkribliak and K orpaniuk houses of carvers from a position of formation of a master’s individual style and proceeding from each master’s impact on the K osiv artistic carving school’s origin. The author pays a specific attention to the technical and technological innovations which are put into practice by a carver as well as to the composition wethods which differ carver’s wares from the rest

Remodelling of gap junctions and connexin expression in diseased myocardium

Gap junctions form the cell-to-cell pathways for propagation of the precisely orchestrated patterns of current flow that govern the regular rhythm of the healthy heart. As in most tissues and organs, multiple connexin types are expressed in the heart: connexin43 (Cx43), Cx40 and Cx45 are found in distinctive combinations and relative quantities in different, functionally-specialized subsets of cardiac myocyte. Mutations in genes that encode connexins have only rarely been identified as being a cause of human cardiac disease, but remodelling of connexin expression and gap junction organization are well documented in acquired adult heart disease, notably ischaemic heart disease and heart failure. Remodelling may take the form of alterations in (i) the distribution of gap junctions and (ii) the amount and type of connexins expressed. Heterogeneous reduction in Cx43 expression and disordering in gap junction distribution feature in human ventricular disease and correlate with electrophysiologically identified arrhythmic changes and contractile dysfunction in animal models. Disease-related alterations in Cx45 and Cx40 expression have also been reported, and some of the functional implications of these are beginning to emerge. Apart from ventricular disease, various features of gap junction organization and connexin expression have been implicated in the initiation and persistence of the most common form of atrial arrhythmia, atrial fibrillation, though the disparate findings in this area remain to be clarified. Other major tasks ahead focus on the Purkinje/working ventricular myocyte interface and its role in normal and abnormal impulse propagation, connexin-interacting proteins and their regulatory functions, and on defining the precise functional properties conferred by the distinctive connexin co-expression patterns of different myocyte types in health and disease

Wernicke's Encephalopathy in Acute and Chronic Kidney Disease:A Systematic Review

Thiamine (vitamin B1) deficiency is relatively common in patients with kidney disease. Wernicke's encephalopathy (WE) is caused by vitamin B1 deficiency. Our aim was to systematically review the signs and symptoms of WE in patients with kidney disease. We conducted a systematic literature review on WE in kidney disease and recorded clinical and radiographic characteristics, treatment and outcome. In total 323 manuscripts were reviewed, which yielded 46 cases diagnosed with acute and chronic kidney disease and WE published in 37 reports. Prodromal characteristics of WE were loss of appetite, vomiting, weight loss, abdominal pain, and diarrhea. Parenteral thiamine 500 mg 3 times per day often led to full recovery, while Korsakoff's syndrome was found in those receiving low doses. To prevent WE in kidney failure, we suggest administering high doses of parenteral thiamine in patients with kidney disease who present with severe malnutrition and (prodromal) signs of thiamine deficiency.</p

Pennsylvania Folklife Vol. 16, No. 3

• Reminiscences of a Boyhood in Reading, 1883-1890 • Preserving York\u27s Architectural Heritage • Jordan Museum of the Twenty • Pennsylvania Broadsides: II • Memoirs of a Lutheran Minister, 1850-1881 • Notes and Documents: Nicknames from a Mennonite Family • The Crafts at Newport • Anglicizing the Pennsylvania Dutch, 1966 and 1875 • Nicknames: Folk-Cultural Questionnaire #3https://digitalcommons.ursinus.edu/pafolklifemag/1027/thumbnail.jp

Body composition is associated with tacrolimus pharmacokinetics in kidney transplant recipients

PURPOSE: A population pharmacokinetic (popPK) model may be used to improve tacrolimus dosing and minimize under- and overexposure in kidney transplant recipients. It is unknown how body composition parameters relate to tacrolimus pharmacokinetics and which parameter correlates best with tacrolimus exposure. The aims of this study were to investigate which body composition parameter has the best association with the pharmacokinetics of tacrolimus and to describe this relationship in a popPK model. METHODS: Body composition was assessed using bio-impedance spectroscopy (BIS). Pharmacokinetic analysis was performed using nonlinear mixed effects modeling (NONMEM). Lean tissue mass, adipose tissue mass, over-hydration, and phase angle were measured with BIS and then evaluated as covariates. The final popPK model was evaluated using goodness-of-fit plots, visual predictive checks, and a bootstrap analysis. RESULTS: In 46 kidney transplant recipients, 284 tacrolimus concentrations were measured. The base model without body composition parameters included age, plasma albumin, plasma creatinine, CYP3A4 and CYP3A5 genotypes, and hematocrit as covariates. After full forward inclusion and backward elimination, only the effect of the phase angle on clearance (dOFV =  − 13.406; p < 0.01) was included in the final model. Phase angle was positively correlated with tacrolimus clearance. The inter-individual variability decreased from 41.7% in the base model to 34.2% in the final model. The model was successfully validated. CONCLUSION: The phase angle is the bio-impedance spectroscopic parameter that correlates best with tacrolimus pharmacokinetics. Incorporation of the phase angle in a popPK model can improve the prediction of an individual’s tacrolimus dose requirement after transplantation. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00228-022-03323-0

Influence of V5/6-His Tag on the Properties of Gap Junction Channels Composed of Connexin43, Connexin40 or Connexin45

HeLa cells expressing wild-type connexin43, connexin40 or connexin45 and connexins fused with a V5/6-His tag to the carboxyl terminus (CT) domain (Cx43-tag, Cx40-tag, Cx45-tag) were used to study connexin expression and the electrical properties of gap junction channels. Immunoblots and immunolabeling indicated that tagged connexins are synthesized and targeted to gap junctions in a similar manner to their wild-type counterparts. Voltage-clamp experiments on cell pairs revealed that tagged connexins form functional channels. Comparison of multichannel and single-channel conductances indicates that tagging reduces the number of operational channels, implying interference with hemichannel trafficking, docking and/or channel opening. Tagging provoked connexin-specific effects on multichannel and single-channel properties. The Cx43-tag was most affected and the Cx45-tag, least. The modifications included (1) Vj-sensitive gating of Ij (Vj, gap junction voltage; Ij, gap junction current), (2) contribution and (3) kinetics of Ij deactivation and (4) single-channel conductance. The first three reflect alterations of fast Vj gating. Hence, they may be caused by structural and/or electrical changes on the CT that interact with domains of the amino terminus and cytoplasmic loop. The fourth reflects alterations of the ion-conducting pathway. Conceivably, mutations at sites remote from the channel pore, e.g., 6-His-tagged CT, affect protein conformation and thus modify channel properties indirectly. Hence, V5/6-His tagging of connexins is a useful tool for expression studies in vivo. However, it should not be ignored that it introduces connexin-dependent changes in both expression level and electrophysiological properties