"Unraveling the mode of action of new promising polymer–ruthenium conjugates." Ultrastructural Pathology, 41(1), pp. 129–130

ABSTRACTIt is estimated that 5.9% of all human deaths are attributable to alcohol consumption and that the harmful use of ethanol ranks among the top five risk factors for causing disease, disability, and death worldwide. Ethanol is known to disrupt phospholipid packing and promote membrane hemifusion at lipid bilayers. With the exception of mitochondria involved in hormone synthesis, the sterol content of mitochondrial membranes is low. As membranes that are low in cholesterol have increased membrane fluidity and are the most easily disordered by ethanol, we hypothesize that mitochondria are sensitive targets for ethanol damage. HeLa cells were exposed to 50 mM ethanol and the direct effects of ethanol on cellular ultrastructure were examined utilizing transmission electron microscopy. Our ultramicroscopic analysis revealed that cells exposed to ethanol harbor fewer incidence of apoptotic morphology; however, significant alterations to mitochondria and to nuclei occurred. We observed statistical increases in the amount of irregular cells and cells with multiple nuclei, nuclei harboring indentations, and nuclei with multiple nucleolus-like bodies. Indeed, our analysis revealed that mitochondrial damage is the most extensive type of cellular damage. Rupturing of cristae was the most prominent damage followed by mitochondrial swelling. Ethanol exposure also resulted in increased amounts of mitochondrial rupturing, organelles with linked membranes, and mitochondria localizing to indentations of nuclear membranes. We theorize that these alterations could contribute to cellular defects in oxidative phosphorylation and, by extension, the inability to generate regular levels of cellular adenosine triphosphate.

ABSTRACTCyclosporine A (CsA) is an immunosuppressor agent, which is most frequently used in transplant surgeries and in the treatment of autoimmune diseases. This study was undertaken to investigate the protective effects of ellagic acid (EA) against CsA-induced testicular histopathology and ultrastructure changes, oxidative stress, and cytogenotoxicity in male albino rats. Rats were divided into six groups; the first group was used as a control, the second group received a subcutaneous injection of slightly alkaline solution, the third group received olive oil orally, the fourth group was injected subcutaneously with EA at a dose of 10 mg/kg b. wt./day, the fifth group was treated with CsA as oral solution at a dose of 15 mg/kg b. wt for 30 days, and the sixth group was treated with CsA simultaneously with EA. Treatment with EA simultaneously with CsA resulted in significant protection. The positive control animals taking CsA alone showed marked histopathological, ultrastructure, and genetic manifestations accompanied by an elevated content of lipid peroxidation and marked reduction of catalase (CAT), peroxidase (Px) activity, and glutathione concentration in the homogenate of testis tissues. The toxic side effects in testis and bone marrow tissues were greatly ablated with a significant reduction in lipid peroxidation level and elevation in CAT and Px activities and glutathione concentration when using EA. Thus, EA may be used in combination with CsA to improve the histopathological, oxidative stress, and cytogenotoxicity parameters of testicular toxicity induced by CsA due to its antioxidant effects.

ABSTRACTOsteogenesis imperfecta (OI) is a heterogeneous group of inherited disorders of bone formation, resulting in low bone mass and an increased propensity to fracture. Over 90% of patients with OI have a mutation in COL1A1/COL1A2, which shows an autosomal dominant pattern of inheritance. In-depth phenotyping and in particular, studies involving manifestations in the skin connective tissue have not previously been undertaken in OI. The aims of the study were to perform histological and ultrastructural examination of skin biopsies in a cohort of patients with OI; to identify common and distinguishing features in order to inform genotype-phenotype correlation; and to identify common and distinguishing features between the different subtypes of OI. As part of the RUDY (Rare Diseases in Bone, Joints and/or Blood Vessels) study, in collaboration with the NIHR Rare Diseases Translational Research Collaboration, we undertook a national study of skin biopsies in patients with OI. We studied the manifestations in the skin connective tissue and undertook in-depth clinical and molecular phenotyping of 16 patients with OI. We recruited 16 patients: analyses have shown that in type 1 collagen mutation positive patients (COL1A1/ COL1A2) (n-4/16) consistent findings included: variable collagen fibril diameter (CFD) and presence of collagen flowers. Histological examination in these patients showed an increase in elastic fibers that are frequently fragmented and clumped. These observations provide evidence that collagen flowers and CFD variability are consistent features in OI due to type 1 collagen defects and reinforce the need for accurate phenotyping in conjunction with genomic analyses.

ABSTRACTEculizumab is a monoclonal antibody that inhibits the conversion of complement protein C5 to C5a and C5b. Eculizumab has been used to treat some disorders of complement regulation owing to its ability to inhibit terminal complement activation. The efficacy of eculizumab in reducing complement-mediated microvascular injury in renal allografts is currently the subject of trials. Electron-dense deposit was detected in allograft biopsies from three highly sensitized recipients of renal transplants, all of whom had received prophylactic eculizumab therapy. In two cases, the deposit was probably drug-derived whilst in the third case the deposit was probably derived from recurrent disease. The cases demonstrate the potential difficulty in interpreting electron-dense deposit in renal allograft biopsies, particularly in the setting of eculizumab therapy.

Lipofuscin granules (LGs), the “age pigments”, are autofluorescent cell products from lysosomes that diverge in number and size among brain regions. Human temporal cortex from 20- to 55-year-old epileptic subjects were studied with the fat soluble dye Sudan Black, under confocal and electron microscopy. Ultrastructural analysis showed that with age LGs increase in area, but not in number. Proportionally to the LGs area, the electron lucid portion increases and the electron dense reduces over time. The robust increase in lipid components is possibly due to modifications in the neuronal metabolism with age in physiological and pathological conditions.

The surface changes of natural incipient caries in human teeth were examined by scanning electron microscopy. Numerous small round depressions due to dissolved prism ends are observed. The prism sheaths seem to be preferentially demineralized, followed by demineralization of prism cores. Perikymata are well-pronounced. Focal holes and relatively large dissolution areas can be present. A new prismatic pattern of destruction with an appearance of fish scales is found. Evidence of remineralization of the incipient carious lesions is seen on the surfaces of the lesions. This study disagrees with the concept of an intact enamel surface layer.

Mitochondrial morphology was studied in cultivated myoblasts obtained from patients with mitochondrial disorders, including CPEO, MELAS and TMEM70 deficiency. Mitochondrial networks and ultrastructure were visualized by fluorescence microscopy and transmission electron microscopy, respectively. A heterogeneous picture of abnormally sized and shaped mitochondria with fragmentation, shortening, and aberrant cristae, lower density of mitochondria and an increased number of “megamitochondria” were found in patient myoblasts. Morphometric Fiji analyses revealed different mitochondrial network properties in myoblasts from patients and controls. The small number of cultivated myoblasts required for semiautomatic morphometric image analysis makes this tool useful for estimating mitochondrial disturbances in patients with mitochondrial disorders.

Ameloblastoma is a borderline tumor of odontogenic origin, with a high recurrence rate and possible local aggressiveness. The etiopathogenetic factors involved in its occurrence are not still defined and our study has been precisely aimed to search for novel factors associated with its development. Sections cut from paraffin blocks, containing the representative specimens of 18 different ameloblastomas, collected in a 15-year period (1999–2014), have been observed by an environmental scanning electron microscope, in order to search micro- and nano-sized particles and to identify their composition. In all the neoplastic cases, micro- and nano-sized metallic debris, differing in size and composition, have been detected inside the ameloblastomatous cells. On the contrary, the total absence of metallic particles in the healthy control cases has been emerged. Our results reveal a relationship between ameloblastoma and metallic particulate. The cigarette smoke and the routine dental practice appear the most probable source for the presence of these biopersistant inorganic particles inside the neoplastic cells.