Ketogenic diets cause opposing changes in synaptic morphology in CA1 hippocampus and dentate gyrus of late-adult rats

Ketogenic diets (KDs) have beneficial effects on several diseases, such as epilepsy, mitochondriopathies, cancer, and neurodegeneration. However, little is known about their effects on aging individuals. In the present study, late-adult (19-month-old) rats were fed for 8 weeks with two medium chain triglycerides (MCT)-KDs, and the following morphologic parameters reflecting synaptic plasticity were evaluated in stratum moleculare of hippocampal CA1 region (SM CA1) and outer molecular layer of hippocampal dentate gyrus (OML DG): average area (S), numeric density (Nv(s)), and surface density (Sv) of synapses, and average volume (V), numeric density (Nv(m)), and volume density (Vv) of synaptic mitochondria. In SM CA1, MCT-KDs induced the early appearance of the morphologic patterns typical of old animals (higher S and V, and lower Nv(s) and Nv(m)). On the contrary, in OML DG, Sv and Vv of MCT-KDs-fed rats were higher (as a result of higher Nv(s) and Nv(m)) versus controls; these modifications are known to improve synaptic function and metabolic supply. The opposite effects of MCT-KDs might reflect the different susceptibility to aging processes: OML DG is less vulnerable than SM CA1, and the reactivation of ketone bodies uptake and catabolism might occur more efficiently in this region, allowing the exploitation of their peculiar metabolic properties. Present findings provide the first evidence that MCT-KDs may cause opposite morphologic modifications, being potentially harmful for SM CA1 and potentially advantageous for OML DG. This implies risks but also promising potentialities for their therapeutic use during aging.     

Rhu-Epo down-regulates pro-tumorigenic activity of cancer-associated fibroblasts in multiple myeloma

We have previously demonstrated that recombinant human erythropoietin (rHuEpo) is involved in the regulation of the angiogenic response in multiple myeloma (MM) through a direct effect on macrophages and endothelial cells isolated from the bone marrow of patients with MM. The aim of the present study was designed to determine the effects of rHuEpo on cancer-associated fibroblasts (CAFs) from monoclonal gammopathy of undetermined significance (MGUS) and MM patients by means of in vitro and in vivo assays. rHuEpo treatment reduces the expression of mRNA levels of fibroblast activation markers, namely alpha smooth actin (αSMA) and fibroblast activation protein (FAP) in MGUS and MM CAFs, and of pro-inflammatory and pro-angiogenic cytokines, including interleukin (IL)-6 and IL-8, vascular endothelial growth factor-A (VEGF-A), fibroblast growth factor-2 (FGF-2), and hepatocyte growth factor (HGF) in MM CAFs. Moreover, rHuEpo inhibits the proliferative activity of MM CAFs and increased the apoptosis of MGUS and MM CAFs. Overall, these data suggest that rHu-Epo down-regulates CAFs pro-tumorigenic activity. Moreover, these results are not suggestive for a pro-angiogenic activity of rHuEpo on CAFs. In fact, rHuEpo pre-treatment induces a low angiogenic response in vivo in the chorioallantoic membrane (CAM) assay of MGUS and MM CAFs conditioned medium, not comparable to that of a well-known angiogenic cytokine, VEGF-A, tested in the same assay.     

S-glutathionylation of metallothioneins by nitrosative/oxidative stress

Cystein residues within metallothionein (MT) structure have been shown to be particularly prone to S-nitrosylation. The objective of this study was to examine the possibility that MTs undergo S-glutathionylation under nitrosative/oxidative stress. MT from rabbit liver was treated with different concentrations of GSNO, diamide plus GSH or H₂O₂ plus GSH. Parallel sets of samples were treated with 10 mM DTT for 30 min at 37 °C to reduce mixed disulphides. Incubations were then processed for Western blot or dot-immunobinding assay. Western blot with anti-MT or anti-GSH were also performed on peripheral blood mononuclear cell extracts. Structural aspects of S-glutathionylation of MTs were also examined. Treatment with GSNO, diamide/GSH or H₂O₂/GSH induced a dose-dependent increase in the levels of MT S-glutathionylation. This effect was completely reversed by treatment with the reducing agent DTT, indicating that S-glutathionylation of MT protein was related to formation of protein-mixed disulphides. Structural analysis of rat MT indicated that Cys residues located in the N-terminal domain of the protein are the likely targets for S-glutathionylation, both for their solvent accessibility and electrostatics induced reactivity. S-Glutathionylation of MT, given its reversibility, would provide protection from irreversible oxidation of Cys residues, thus representing a mechanism of high potential biological relevance.     

Do concomitant diseases and therapies affect the persistence of ulcer symptoms in the elderly?

Risk factors of slow healing were previously researched in a large sample of duodenal (DU) and gastric ulcer (GU) patients over 65 years of age; persistence of ulcer symptoms was proven the most reliable factor in predicting nonhealing ulcer, while ulcer size was of importance only for DU. We aimed to complete the analysis, with a more careful evaluation of concomitant diseases and therapies. Ranitidine 300 mg daily was given for four to eight weeks to 310 GU and 699 DU patients. Ninety-three patients dropped out of the study: 79/294 gastric ulcers and 138/635 duodenal ulcers were unhealed after four weeks. Cardiovascular, gastrointestinal, and pulmonary disorders were the most frequent concomitant diseases; NSAIDs, cardiovascular drugs, and antihypertensives were the most frequent concomitant therapies. Esophagitis was diagnosed in 15.5% of patients. Ulcer healing was the major determinant of persistence of ulcer symptoms; esophagitis emerged as an important adjunctive and independent factor. Use of hypoglycemic agents in the whole sample and smoking habit (in GU) may have also a role. With persistence of ulcer symptoms removed from the analysis, ulcer size was the most constant factor affecting ulcer healing. NSAID use, cardiovascular disorders, esophagitis (in GU), and concomitant therapy with cardiovascular drugs (in DU) also play a role. In conclusion, persistence of ulcer symptoms, the major indicator of slow ulcer healing in the elderly, is independently affected also by the presence of esophagitis. Use of hypoglycemic agents and smoking habit may also have a role in persistence of ulcer symptoms. NSAIDs, cardiovascular disorders, cardiovascular drugs, and esophagitis affect ulcer healing, for which the most constant indicators remained persistence of ulcer symptoms and ulcer size.This study was performed under the auspices of the R. Farini Foundation for Gastrointestinal Research.     

"Ultrasound comet-tail images": a marker of pulmonary edema: a comparative study with wedge pressure and extravascular lung water

BACKGROUND: Echographic examination of the lung surface may reveal multiple "comet-tail images" originating from water-thickened interlobular septa. These images could be useful for noninvasive assessment of interstitial pulmonary edema. STUDY OBJECTIVE: The purpose of this study was to assess the diagnostic accuracy of lung comet-tail images compared with chest radiography, wedge pressure, and extravascular lung water (EVLW) quantified by the indicator dilution method (PiCCO System, version 4.1; Pulsion Medical Systems; Munich, Germany). METHODS AND PATIENTS: We enrolled 20 patients (mean age, 62.6 +/- 11.5 years [+/- SD]). Patients were studied before, immediately after, and 24 h following cardiac surgery with chest ultrasound, chest radiography, pulmonary artery catheterization, and the PiCCO system. Performing echo scanning (right and left hemithorax, from second to fourth intercostal space, from parasternal to midaxillary line), an individual patient comet score was obtained by summing the number of comets in each scanned space. RESULTS: A total of 60 comparisons were obtained. Significant positive linear correlations were found between comet score and EVLW determined by the PiCCO System (r = 0.42, p = 0.001), between comet score and wedge pressure (r = 0.48, p = 0.01), and between comet score and radiologic lung water score (r = 0.60, p = 0.0001). CONCLUSIONS: The presence and the number of comet-tail images provide reliable information on interstitial pulmonary edema. Therefore, ultrasonography represent an attractive, easy-to-use, bedside diagnostic tool for assessing cardiac function and pulmonary congestion.     

Morphometric investigations of the mitochondrial damage in ceroid lipopigment accumulation due to vitamin E deficiency

Numeric (Nv) and volume (Vv) densities, as well as the average size (skeleton: Sk) of synaptic mitochondria from adult, normally fed and adult, vitamin E deficient animals (11 months of age) were semiautomatically measured by computer-assisted morphometry in the cerebellar granular layer. Nv, Vv and the average mitochondrial volume (V) were measured on perikaryal Purkinje cell organelles preferentially stained for succinic dehydrogenase (SDH) activity. Adult vitamin E deficient animals showed a significant decrease of Nv, a significant increase of Sk and an unchanged value of Vv. While in adult normally fed animals the mitochondria of increased size (Sk>5 microm) were 5.3%, in the adult vitamin E deficient rats this fraction accounted for 25.5%. In Purkinje cell perikarya, vitamin E deficiency resulted in a significant decrease of Vv, Nv and V, as well as a steeper reduction of the percentage of SDH-positive mitochondria of larger size. Taken together, these findings document that vitamin E deficiency is responsible of mitochondrial morphometric alterations in adult rats. Structurally deteriorated mitochondria are reported to play a role in producing increased amounts of free radicals, which can facilitate the accumulation of ceroid pigment.     

Surface markers: An identity card of endothelial cells

All endothelial cells have the common characteristic that they line the vessels of the blood circulatory system. However, endothelial cells display a large degree of heterogeneity in the function of their location in the vascular tree. In this article, we have summarized the expression patterns of a number of well‐accepted endothelial surface markers present in normal microvascular endothelial cells, arterial and venous endothelial cells, lymphatic endothelial cells, tumor endothelial cells, and endothelial precursor cells.     

Tumor necrosis factor receptor-associated periodic syndrome as a model linking autophagy and inflammation in protein aggregation diseases

Autophagy prevents cellular damage by eliminating insoluble aggregates of mutant misfolded proteins, which accumulate under different pathological conditions. Downregulation of autophagy enhances the inflammatory response and thus represents a possible common pathogenic event underlying a number of autoinflammatory syndromes, such as tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS). The pathogenesis of other monogenic or complex disorders that display symptoms of excessive inflammation also involve the autophagy pathway. Studies have shown that TRAPS-associated TNFRSF1A mutations induce cytoplasmic retention of the TNFR1 receptor, defective TNF-induced apoptosis, and production of reactive oxygen species (ROS). Furthermore, autophagy impairment may account for the pathogenic effects of TNFRSF1A mutations, thus inducing inflammation in TRAPS. In this review, we summarize the molecular interactions and functional links between autophagy with regard to nuclear factor-kappa B activation, ROS production, and apoptosis. Furthermore, we propose a complex interplay of these pathways as a model to explain the relationship between mutant protein misfolding and inflammation in genetically determined and aggregation-prone diseases. Accordingly, autophagy function should be investigated in all diseases showing an inflammatory component, and for which the molecular pathogenesis is still unclear.