Vesna Lackovic

Endothelial Keratoplasty without Descemet’s Membrane Stripping: Histologic and Ultrastructural Findings

Aim: To report histologic and ultrastructural findings of endothelial keratoplasty (EK) performed without Descemet’s membrane stripping. Methods: Clinical techniques, histology, and transmission electron microscopy. Results: A 55-year-old woman was referred to us, after 2 unsuccessful penetrating keratoplasties (PKs), for pseudophakic bullous keratopathy. An 8.0-mm EK without Descemet’s membrane stripping was performed, and clarity was restored to the failed penetrating regraft. A year later, the lamellar graft failed, and a third PK was performed for intractable corneal edema. Light microscopy of a semi-thin section of the trephined corneal button showed both the recipient’s and the donor’s Descemet’s membrane, the well-preserved structure of the full-thickness graft, and marked edema of the adherent stromal carrier of the endothelial transplant. The host endothelium was absent at the interface, and the donor endothelium was atrophic. Electron microscopy revealed regularity and even spacing of collagen fibrils as well as quiet keratocytes on both sides of Descemet’s membrane at PK-EK interface. Conclusion: These findings suggest a lack of proliferation and hypercellular scarring, and offer further support to the already proven merits of EK.

Micro- and nanostructures of iridescent wing scales in purple emperor butterflies (Lepidoptera: Apatura ilia and A. iris).

Apatura ilia (Denis and Schiffermüller, 1775) and A. iris (Linnaeus, 1758) are fascinating butterflies found in the Palaearctic ecozone (excepting the north of Africa). The wings of these insects are covered with a great number of two types of scales positioned like roof tiles. Type I scales are on the surface, while type II scales are situated below them. The structural color of the type I scales is recognized only on the dorsal side of both the fore and hind wings of the males of the aforementioned species. Both types of scales are responsible for pigment color of the wings, but iridescence is observed only in the type I scales. The brilliant structural color is due to a multilayer structure. The features of the scales, their dimensions and fine structure were obtained using scanning electron microscopy. Cross sections of the scales were then analyzed by transmission electron microscopy. The scales of the “normal” and clytie forms of A. ilia have a different nanostructure, but are of the same type. A similar type of structure, but with a different morphology, was also noticed in A. iris. The scales of the analyzed species resemble the scales of tropical Morpho butterflies. Microsc. Res. Tech., 2012.

The acidophilic nature of neuronal Golgi impregnation.

The mechanisms of Golgi impregnation of neurons has remained enigmatic for decades. Recently, it was suggested that divalent (di)chromate anions play a role in the Golgi impregnation process. Therefore, we incubated slices of (para)formaldehyde-fixed rat brain tissue in solutions of potassium (di)chromate, phosphate, chloride or nitrate at pH 6 or 7. Slices were then immersed in solutions of silver nitrate and processed for light microscopical analysis. At pH 6, dichromate probes resulted in dense and homogeneous impregnation of neuronal cytoplasm (typical impregnation). At pH 7, chromate probes showed solely partial cytoplasmic and heavy nuclear-region neuron impregnation (atypical impregnation). Phosphate probes at pH 6 resulted in typical impregnation, whereas at pH 7 phosphate probes gave atypical impregnation. Both at pH 6 and 7, chloride and nitrate probes did not yield any Golgi impregnation. These findings confirmed the pH-dependence of silver-chromate Golgi impregnation as well as the correctness of corresponding acidic silver-phosphate impregnation. Our study revealed a previously unknown, strong anion-dependence of Golgi impregnation, suggesting that hydrogenated monovalent anions are carriers of the neuron impregnation.

Skin and Sural Nerve Biopsies: Ultrastructural Findings in the First Genetically Confirmed Cases of CADASIL in Serbia

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited vascular disorder caused by Notch3 gene mutations. The main histopathological hallmark is granular osmiophilic material (GOM) deposited in the close vicinity of vascular smooth muscle cells (VSMCs). The authors report the first 7 ultrastructurally and genetically confirmed cases of CADASIL in Serbia. Samples of skin and sural nerve were investigated by transmission electron microscopy. GOM deposits were observed around degenerated VSMCs in all the skin biopsies examined. Sural nerve biopsies revealed severe alterations of nerve fibers, endoneurial blood vessels with GOM deposits, endoneurial fibroblasts, and perineurial myofibroblasts. Total genomic DNA was extracted from peripheral blood leukocytes, and exons 2–6 of the Notch3 gene were amplified by PCR and subsequently sequenced. Four different mutations in exons 2 (Cys65Tyr), 3 (Gly89Cys and Arg90Cys), and 6 (Ala319Cys), which determine the CADASIL disease, were detected among all described patients. A novel missense mutation Gly89Cys involving exon 3 was detected. Due to the difficulties in the determination of the Notch3 mutations, these data suggest that electron microscopic analysis for GOMs in dermal vessel wall provides a rapid and reliable screening method for this disease.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy with severe factor XII deficiency

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited adult-onset microangiopathy caused by missense mutations in the Notch3gene on chromosome 19. However, common vascular risk factors may additionally modify clinical expression and progression of the disease. The role of various prothrombotic factors has also been implied. We report a case of a middle-aged man with typical clinical, neuroimaging and histological features of CADASIL, but with notably prolonged activated partial thromboplastin time. Hematological investigations revealed severe clotting Factor XII deficiency. This case illustrates that the occurrence of vascular risk factors should not be overlooked in patients with CADASIL.

A novel Notch3 Gly89Cys mutation in a Serbian CADASIL family

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common heritable cause of stroke and vascular dementia in adults. We present a family from Serbia presenting with stroke and depression in the lack of vascular risk factors, with brain MRI indicating CADASIL. A novel NOTCH3 Gly89Cys mutation was located in exon 3. This report illustrates that in the setting of a positive family history with typical clinical and MRI features, even with an atypical form of pedigree, a high suspicion of CADASIL should lead to genetic testing.

[Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)--three case reports from Serbia].

INTRODUCTION Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary microangiopathy leading to recurrent strokes and vascular dementia in young and middle-aged patients. The diagnosis of CADASIL is based on typical clinical presentation and characteristic magnetic resonance imaging (MRI) changes, and has to be confirmed by biopsy of the sural nerve, muscle and skin, as well as by genetic analysis. Mutations within the Notch3 gene were identified as the underlying genetic defect in CADASIL. CASE OUTLINE The clinical manifestations of the first presented patient with migraine from the age of thirteen, stroke without vascular risk factors and stepwise progression of vascular dementia comprising the typical clinical picture of CADASIL, were confirmed after seven years with pathological verification. The second presented case did not satisfy the clinical criteria for CADASIL. His stroke was considered to be related with vascular risk factors--diabetes mellitus and hypertension. The aetiological diagnosis was established only when his brother without vascular risk factors presented with similar clinical manifestations. CONCLUSION Until the development of the new neuroimaging techniques like MRI, pathologic and genetic analysis, CADASIL was considered as a rare disorder. However, the increasing number of CADASIL families has been identified throughout the world showing that this entity is usually underdiagnosed. This article presents three patients from two Serbian families with clinical suspicion of CADASIL verified by pathologic examination.

Three-layered ventricular septum of the helical heart: functional anatomy and clinical relevance

Results IVS displays significant fiber disarray at the boundaries of LV and RV free walls, and contains an intriguing structure that may be freshly examined by the HVMB dissection. These dissections contradict the concept that the interventricular septum belongs to the LV, since both ventricles participate in its formation. Ascending and descending segments od the HVMB provide the origin and significance of mayor “septal fiber crossing”. Conventional low resolution ultrasound imaging of the ventricular septum previously identified the border of this crossing as hyperechogenic “septal line”. We suspect the overlap of the crossing of descending and ascending segments creates this “bright line”. Histological analyses have shown that septal RV and LV fibers create a connective tissue true space. Coronary artery septal branches run through this space, a fact, which may be useful in Ross’ procedure.