Silver Impregnation Research Articles

Immunofluorescence and ultrastructural analysis of the chromatoid body during spermatogenesis of Triatoma platensis and T. rubrovaria (Hemiptera, Triatominae)

This study sought to analyze spermatogenesis in two species of triatomines (Triatoma rubrovaria and T. platensis) by focusing on the chromatoid body (CB) during three stages of spermatogenesis (spermatocytogenesis, meiosis, and spermiogenesis). The cytochemistry technique known as silver impregnation revealed nucleolar persistence. We suggest that this phenomenon is fundamental to the formation of the CB during spermatogenesis, as it allows for the nucleolus or nucleolar fragments to maintain their transcriptional activity during the entire meiosis phase and to apply all transcribed RNA to CB formation. The ultrastructural analysis of T. platensis and T. rubrovaria spermatids revealed the presence of the nucleolus within the spermatid nucleus, as well as the CB near the nuclear membrane. Immunofluorescence for fibrillarin revealed the presence of protein in both the nucleolus and the cytoplasm of spermatogonia. Based on these findings, we suggest that the formation of the CB begins during the first phase of spermatogenesis, or spermatocytogenesis. Furthermore, we also observed the presence of fibrillarin protein in the CB near the elongating spermatids. Unlike the spermatogonia, spermatids showed no fibrillarin markings in the nucleolar region, a finding which is consistent with the lack of post-meiotic transcriptional activity during triatomine spermiogenesis. Thus, this study suggests that the formation of the CB begins during spermatocytogenesis and is intensified by transcriptional activity when nucleolar persistence occurs in meiosis. Moreover, the findings are consistent with the absence of transcriptional activity in the nucleolus during spermiogenesis, and they demonstrate that all transcriptional activity during spermatid differentiation is supported by the CB.

From the Cajal alumni Achúcarro and Río-Hortega to the rediscovery of never-resting microglia.

Under the guidance of Ramón y Cajal, a plethora of students flourished and began to apply his silver impregnation methods to study brain cells other than neurons: the neuroglia. In the first decades of the twentieth century, Nicolás Achúcarro was one of the first researchers to visualize the brain cells with phagocytic capacity that we know today as microglia. Later, his pupil Pío del Río-Hortega developed modifications of Achúcarro's methods and was able to specifically observe the fine morphological intricacies of microglia. These findings contradicted Cajal's own views on cells that he thought belonged to the same class as oligodendroglia (the so called “third element” of the nervous system), leading to a long-standing discussion. It was only in 1924 that Río-Hortega's observations prevailed worldwide, thus recognizing microglia as a unique cell type. This late landing in the Neuroscience arena still has repercussions in the twenty first century, as microglia remain one of the least understood cell populations of the healthy brain. For decades, microglia in normal, physiological conditions in the adult brain were considered to be merely “resting,” and their contribution as “activated” cells to the neuroinflammatory response in pathological conditions mostly detrimental. It was not until microglia were imaged in real time in the intact brain using two-photon in vivo imaging that the extreme motility of their fine processes was revealed. These findings led to a conceptual revolution in the field: “resting” microglia are constantly surveying the brain parenchyma in normal physiological conditions. Today, following Cajal's school of thought, structural and functional investigations of microglial morphology, dynamics, and relationships with neurons and other glial cells are experiencing a renaissance and we stand at the brink of discovering new roles for these unique immune cells in the healthy brain, an essential step to understand their causal relationship to diseases.

P0250 : Effect of irreversible electroporation (IRE) on the porcine liver: comparison with radiofrequency ablation

Background and Aims: Irreversible electroporation (IRE) is a promising, non-thermal ablation therapy for hepatocellular carcinoma, which, unlike radiofrequency thermal ablation (RFA), induces apoptosis through irreversible formation of nanoscale pores in the cell membrane with delivery of high-voltage electric current and is considered to improve safety in the vicinity of heat-sensitive blood vessel and bile duct. The aim of the present study is to clarify the acute pathological effect of IRE on the liver and also to compare with effect of RFA. Methods: Three pigs underwent ultrasound-guided IRE and RFA of normal liver under general anesthesia and at laparotomy. A total of 9 IRE ablated areas and 3 RFA ablated areas were created. We examined histopathologic findings of ablated areas at 4 hours after therapy with immunohistochemical methods. The pathologic findings according to IRE ablation conditions were compared with findings of RFA. Results: In IRE zones, various degree of congestion and hemorrhage, apoptotic change of hepatocytes, defluxion of portal endothelial cells and cholangitis were observed in hepatic lobules. With the increase in the total pulse number of IRE delivered, these pathological findings became remarkable. NADPH-diaphorase enzyme histochemistry performed in IRE zones demonstrated the stainability is very weak in the hepatic lobule, which reflecting defluxion of hepatocytes and reduced activity of viable hepatocytes in acute phase, while the stainability is lost in the central portion of RFA. Silver impregnation stain and collagen type 4 immunohistochemistry showed that reticular fibers and collagen fibers around the sinusoid remain well-preserved in IRE zones, on the other hand, those in RFA zones are very poorly stained. The vessels in IRE zones demonstrated a relatively intact configuration of positive smooth muscle cells for Caldesmon staining and endothelial cells for Factor 8 staining, with the minimal endothelial damage, while the vessels in RFA zones demonstrated a negative or weakened reaction. Bile duct epithelial cells showed a positive reaction for cytokeratin 7 staining in IRE zones with desquamated cells, while an entirely negative reaction in RFA zones, revealing protein denaturation. Conclusions: Unlike RFA, IRE induces apoptosis of hepatocytes, endothelium of the blood vessels and mucosal membrane of the bile ducts, whereas preservation of sinusoidal framework and vascular structure may have the potential for liver regeneration.

English

This study aimed at investigating the parasitic ciliates on commercial fishes in Luzhou, Sichuan Province, China. Several ciliates were collected from gills of Pelteobagrus fluvidraco. Three trichodinids and one chilodonellid were collected from the gills of the Pelteobagrus fluvidraco. These are Trichodina fluvidraco sp. n., Tripartiella dactylodentata, Tripartieila nana and Chilodonella hexasticha. Descriptions presented here were obtained by examinations of specimens prepared using the dry silver impregnation and Wright-Giemsa staining. For the new species comparisons with closely related species are provided. Key words: Trichodinid, chilodonellid, Trichodina fluvidraco sp. n., Tripartiella dactylodentata, T. nana, Chilodonella hexasticha, Pelteobagrus fluvidraco.

Lars Grimelius and his silver impregnation method—Commentaries on the paper in Upsala Journal of Medical Sciences with the highest number of citations

Citation counting is a comparably new procedure that has become widely used to evaluate single papers but also to rank journals by the so-called impact factor (IF), often determined to the third decimal. This is a phenomenon of the information society and therefore only reliable for later years. However, we can go back to the 1960s. When doing so for Upsala Journal of Medical Sciences, there is one paper which has been cited much more than any other, and that is Lars Grimelius’s ‘A Silver Nitrate Stain for α2 Cells in Human Pancreatic Islets’, published in the journal in 1968 (1). According to the Thomson Reuters database it has been cited 897 times to date. None of the journal’s other papers is even close to that record. The value would have been even higher if the method had not been incorporated in many laboratories as a routine staining for which a citation was regarded as unnecessary.

Investigation of the sorption of mercury vapour from exhaust gas by an Ag-X zeolite

AbstractThe removal of gaseous mercury from flue gases from coal-fired power plants is currently an environmental challenge under investigation. Therefore, the main aim of this paper was to evaluate the suitability of faujasite group zeolites (Na-X) to adsorb mercury compounds. Previous, initial tests showed negligible Hg0 uptake by Na-X zeolite, but silver impregnation improved adsorption markedly. Therefore, the testing of mercury adsorption from flue gases into Ag+- impregnated Na-X synthetic zeolite (Ag-X zeolite) derived from coal fly ash was carried out. This material was characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy, X-ray fluorescence and nitrogen adsorption/desorption before being evaluated for mercury removal from exhaust gas. After preliminary mercury adsorption tests (fixed bed) under a nitrogen atmosphere, the adsorbent was examined with a simulated flue gas composition under various conditions, i.e. weight of zeolite, temperature of experiment and zeolite in powder and granulated forms. The removal of mercury was shown to depend on the sorbent texture (powder or granulate), exhaust gas flow rate and contact time, as well as the temperature of the experiment. The Ag-X zeolite tested reduced the level of mercury in the flue gas and, depending on the experimental conditions, long-time mercury breakthrough ranges from 15 to 40% were obtained. The best results for mercury capture were obtained for granulated material.

Extensive acute axonal damage in pediatric multiple sclerosis lesions.

Axonal damage occurs early in multiple sclerosis (MS) and contributes to the degree of clinical disability. Children with MS more often show disabling and polyfocal neurological symptoms at disease onset than adults with MS. Thus, axonal damage may differ between pediatric and adult MS patients. We analyzed axonal pathology in archival brain biopsy and autopsy samples from 19 children with early MS. Lesions were classified according to demyelinating activity and presence of remyelination. Axonal density and extent of acute axonal damage were assessed using Bielschowsky silver impregnation and immunohistochemistry for amyloid precursor protein (APP), respectively. Axonal injury was correlated with the inflammatory infiltrate as well as clinical characteristics. Results were compared with data from adult MS patients. Acute axonal damage was most extensive in early active demyelinating (EA) lesions of pediatric patients and correlated positively with the Expanded Disability Status Scale at attack leading to biopsy/autopsy. Comparison with 12 adult patients showed a 50% increase in the extent of acute axonal damage in EA lesions from children compared to adults, with the highest number of APP-positive spheroids found prior to puberty. The extent of acute axonal damage correlated positively with the number of lesional macrophages. Axonal density was reduced in pediatric lesions irrespective of the demyelinating activity or the presence of remyelination. Axonal reduction was similar between children and adults. Our results provide evidence for more pronounced acute axonal damage in inflammatory demyelinating lesions from children compared to adults.

Biodiversity of marine scuticociliates (Protozoa, Ciliophora) from China: Description of seven morphotypes including a new species, Philaster sinensis spec. nov.

Seven marine scuticociliates, Philaster sinensis spec. nov., Pseudocohnilembus hargisi Evans and Thompson, 1964. J. Protozool. 11, 344, Parauronema virginianum Thompson, 1967. J. Protozool. 14, 731, Uronemella filificum (Kahl, 1931. Tierwelt. Dtl. 21, 181) Song and Wilbert, 2002. Zool. Anz. 241, 317, Cohnilembus verminus Kahl, 1931, Parauronema longum Song, 1995. J. Ocean Univ. China. 25, 461 and Glauconema trihymene Thompson, 1966. J. Protozool. 13, 393, collected from Chinese coastal waters, were investigated using live observations, silver impregnation methods, and, in the case of the new species, SSU rDNA sequencing. Philaster sinensis spec. nov. can be recognized by the combination of the following characters: body cylindrical, approximately 130–150×35–55μm in vivo; apical end slightly to distinctly pointed, posterior generally rounded; 19–22 somatic kineties; M1 triangular, consisting of 13 or 14 transverse rows of kinetosomes; M2 comprising 10–12 longitudinal rows; CVP positioned at end of SK1; marine habitat. We also provide improved diagnoses for Pseudocohnilembus hargisi, Parauronema virginianum, Uronemella filificum and Parauronema longum based on their original descriptions as well as the present work. Phylogenetic analyses support the monophyly of the genus Philaster.

Terminal innervation of the male genitalia, cutaneous sensory receptors of the male foreskin.

Understanding the types of sensory nerve termini within the glabrous skin of the human male foreskin could throw light on surgical outcomes and therapeutic possibilities for the future. Various receptor types sense changes in temperature, position, pressure, pain, light touch, itch, burning and pleasurable sexual sensations. Similarities and differences in innervation characteristics and density might become apparent when the glans penis is compared with homologous structures in the female genitalia. The aim of this study is to document the presence and characteristics of cutaneous sensory receptors in the human penile foreskin using a histopathological study of the nerve termini to achieve a more complete understanding of sensory experiences. Foreskin samples were obtained from ten boys (aged 1-9 years) who had undergone circumcision. Informed consent was obtained from the parent/legal guardian. The samples were examined after modified Bielschowsky silver impregnation of neural tissue, and immunocytochemistry against gene protein product (PGP) 9.5 and neuron-specific enolase (NSE). PGP 9.5 appeared to be the most sensitive neural marker. Free nerve endings were identified in the papillary dermis visualized as thin fibers, mostly varicose, with either branched or single processes, either straight or bent. Two types of sensory corpuscle were identified: capsulated and non-capsulated. Meissner-like corpuscles were located in the papillary dermis. Capsulated corpuscles resembled typical Pacinian corpuscles, comprising a single central axon surrounded by non-neural periaxonic cells and lamellae. The capsulated corpuscles were strongly positive for PGP 9.5 and NSE. Free nerve endings, Meissner's corpuscles and Pacinian corpuscles are present in the human male foreskin and exhibit characteristic staining patterns.

Terminal innervation of female genitalia, cutaneous sensory receptors of the epithelium of the labia minora.

Little information is available regarding the sensory nerve endings within the glabrous skin of the external female genitalia. The diversity of possible sensations suggests a variety of receptor types. Comprehensive knowledge of the sensory stimuli, including stimulus position, changes in temperature, pressure and pain, is critical for addressing pain and sexual function disorders clinically. The aim of this neuro-histological study is document the presence and characteristics of cutaneous sensory receptors in female genital tissue. Labial skin samples were obtained from ten normal girls (aged 1-9 years). The specimens were waste tissue obtained during surgical intervention. They were all obtained by the senior investigator, a pediatric urologist, after the parent or legal guardian had given informed consent. The specimens were stained by Cajal-type silver impregnation and by immunocytochemistry against protein gene product (PGP) 9.5 and neuron-specific enolase (NSE). PGP 9.5 was the most sensitive neural marker for identifying cutaneous sensory receptors. Free nerve endings (FNEs) in the papillary dermis appeared as thin fibers, varicose, branched or single processed, straight or bent. In the labia minora, FNEs were identified in the strata basale, spinosum and granulosum of the epidermis. Non-capsulated (Meissner-like) corpuscles in the dermal papillae interdigitated with epidermal ridges of the skin. Capsulated corpuscles protruded from the deep dermis into the epidermis. Encapsulated corpuscles and cells located in the inner and outer cores were strongly positive for PGP 9.5. FNEs, Meissner's corpuscles and Pacinian corpuscles are present in the female labia minora and exhibit characteristic staining patterns.

Hippocampal Pyramidal Cell Degeneration and Changes in Creb Protein in <i>Datura stramonium</i> Treated Rats

Datura Stramonium (DS) is a tropical shrub which is available worldwide. It has various uses and is often used to increase the intoxication of certain beverages. The seeds of this plant are very toxic but are commonly smoked in like manner as tobacco. The present study investigated the potential harmful effects of DS on pyramidal cells and CREB protein in the hippocampus of Wistar rats in order to further elucidate the effects of DS seed extract on hippocampal structure. The study was conducted on both male and female Wistar rats (200-250 g). They were first divided into three batches, which were further sub-divided into four groups in each batch with eight animals per group. Ethanolic extract of dried seeds of DS was diluted in normal saline and given to the treatment groups. The treated groups received intraperitoneal administration (i.p.) of 750 mg kg-1 (Bania et al., 2004) of diluted DS seed extracts, once in batch 1, twice in batch 2 and thrice in batch 3 per day respectively for 4 weeks while the control groups received an equivalent of normal saline. The rats were euthanized and Western blot analysis used to evaluate the levels of CREB protein in the rats’ hippocampi. Sections of each hippocampus were histologically processed in all the groups and silver impregnation stain for degenerating axons and neurons was used to elucidate the actions of DS on the pyramidal neurons of the hippocampus. The result of i.p. administration of DS extract (750 mg kg-1) given three times per day to the treated rats showed significant histological changes such as axonal atrophy, cytoplasmic vacuolation and neuronal necrosis of the pyramidal cells of the hippocampus, as well as an increase in CREB protein levels in both male and female rats. Excessive ingestion of DS seeds, therefore, may lead to hippocampal pyramidal cell losses and an increase in CREB protein levels in the hippocampus. This may be implicated in neurological disorders.

Alzheimer's 100th anniversary of death and his contribution to a better understanding of Senile dementia.

Initially the trajectory of the historical forerunners and conceptions of senile dementia are briefly presented, being highlighted the name of Alois Alzheimer who provided clinical and neuropathological indicators to differentiate a group of patients with Senile dementia. Alzheimer's examination of Auguste D's case, studied by him with Bielschowsky's silver impregnation technique, permitted to identify a pathological marker, the intraneuronal neurofibrillary tangles, characterizing a new disease later named after him by Kraepelin - Alzheimer's disease. Over the time this disorder became one of the most important degenerative dementing disease, reaching nowadays a status that may be considered as epidemic.

Identification and structural composition of the blood–spleen barrier in chickens

To identify the existence and composition of the blood–spleen barrier (BSB) in chickens, the microanatomical features of the spleen were investigated by light and transmission electron microscopy, intravenous injection of ink, acid phosphatase reaction, and silver impregnation. The results showed that the white pulp in chicken spleen consists of lymphoid nodules, periarteriolar lymphatic sheaths (PALS) and periellipsoidal lymphatic sheaths (PELS). There was no evidence for the presence of a marginal zone.The splenic ellipsoid was a unique structure, which functioned as a barrier for filtering and phagocytosis. Uptake of carbon particles was limited to the ellipsoid and PELS, 60 min after injection of carbon particles. Reticular fibres were densely distributed in the ellipsoid and extended into the PELS. Ellipsoid-associated cells (EACs), reticular cells and macrophages were acid phosphatase positive. The sheathed capillaries, surrounded by the ellipsoid, were similar to high endothelial venules (HEVs). These findings suggest that the BSB of chickens is present in the ellipsoid and PELS, protecting the spleen from invasion from circulating pathogens. The BSB was a reticular framework, between the arterial and venous vessels, which included cuboidal-shaped endothelial cells, supporting cells, EACs, macrophages, reticular cells and fibres. Lymphocyte migration into the spleen parenchyma is most likely via the HEV-like vessels. These research findings contribute to better understanding of avian immunology and provide an insight into evolutionary differences in the immune system.

Some Aspects of Renal Biopsy for Research

Insufficient international coordination of medical research can result in repetition of studies performed in other countries. Renal biopsy is a valuable diagnostic method; it was broadly used for research in the former Soviet Union. The number of biopsies has decreased since 1990; but medical research is on the increase today. Therefore, the purpose of this review was to remind that, performing renal biopsy or other invasive procedures, the risk-to-benefit ratio should be kept as low as possible. Renal biopsies were taken for research from patients with glomerulonephritis, pyelonephritis, amyloidosis, renovascular hypertension (in some studies from both kidneys), essential hypertension, alcoholism, diabetes mellitus, in congenital hydronephrosis and other urinary tract anomalies. About one third of the biopsy cylinder was routinely embedded in epoxy resin. The epoxy resin sections were made for research but not used for diagnostics, the latter being performed mainly on the basis of paraffin sections and immunofluorescence. Extensive use of renal biopsies without silver impregnation and electron microscopy was accompanied by over diagnosis of glomerulonephritis and corresponding overtreatment. Furthermore, the concept of hypoplastic renal dysplasia, developed on the basis of renal biopsy, probably interfered with the morphological diagnosis of Alport syndrome.

Staining neurons with Golgi techniques in degenerative diseases of the brain.

Staining neurons with Golgi techniques in degenerative diseases of the brain.

Association of nonalcoholic fatty liver disease and liver cancer.

To investigate the association between nonalcoholic fatty liver disease (NAFLD) and liver cancer, and NAFLD prevalence in different liver tumors. This is a retrospective study of the clinical, laboratory and histological data of 120 patients diagnosed with primary or secondary hepatic neoplasms and treated at a tertiary center where they underwent hepatic resection and/or liver transplantation, with subsequent evaluation of the explant or liver biopsy. The following criteria were used to exclude patients from the study: a history of alcohol abuse, hepatitis B or C infection, no tumor detected in the liver tissue examined by histological analysis, and the presence of chronic autoimmune hepatitis, hemochromatosis, Wilson's disease, or hepatoblastoma. The occurrence of NAFLD and the association with its known risk factors were studied. The risk factors considered were diabetes mellitus, impaired glucose tolerance, impaired fasting glucose, body mass index, dyslipidemia, and arterial hypertension. Presence of reticulin fibers in the hepatic neoplasms was assessed by histological analysis using slide-mounted specimens stained with either hematoxylin and eosin or Masson's trichrome and silver impregnation. Analysis of tumor-free liver parenchyma was carried out to determine the association between NAFLD and its histological grade. No difference was found in the association of NAFLD with the general population (34.2% and 30.0% respectively, 95%CI: 25.8-43.4). Evaluation by cancer type showed that NAFLD was more prevalent in patients with liver metastasis of colorectal cancer than in patients with hepatocellular carcinoma and intrahepatic cholangiocarcinoma (OR = 3.99, 95%CI: 1.78-8.94, P < 0.001 vs OR = 0.60, 95%CI: 0.18-2.01, P = 0.406 and OR = 0.70, 95%CI: 0.18-2.80, P = 0.613, respectively). There was a higher prevalence of liver fibrosis in patients with hepatocellular carcinoma (OR = 3.50, 95%CI: 1.06-11.57, P = 0.032). Evaluation of the relationship between the presence of NAFLD, nonalcoholic steatohepatitis, and liver fibrosis, and their risk factors, showed no significant statistical association for any of the tumors studied. NAFLD is more common in patients with liver metastases caused by colorectal cancer.

Cellular neuropathology associated with cognitive and behavioural dysfunction in a mouse model of Williams-Beuren syndrome

Event Abstract Back to Event Cellular neuropathology associated with cognitive and behavioural dysfunction in a mouse model of Williams-Beuren syndrome Cecilia Chin Roei Chang1*, Cesar Canales2*, John Power3*, Anthony Hannan4*, Edna Hardeman2* and Stephen Palmer1* 1 University of New South Wales, School of Medical Sciences, Australia 2 Univeristy of New South Wales, School of Medical Sciences, Australia 3 University of New South Wales, Translational Neuroscience Facility, Australia 4 The Florey Institute of Neuroscience and Mental Health, Neural Plasticity , Australia Williams-Beuren Syndrome (WBS) is a neurodevelopmental genetic disorder caused by the hemizygous deletion of 28 genes on chromosome 7q11.23. Genotype/phenotype correlations in patients with atypical deletions suggest that one of these genes, GTF2IRD1, discovered in our laboratory plays a major role in the neurological characteristics of WBS. Affected individuals show mental retardation and a unique cognitive and behavioural profile. We have generated targeted Gtf2ird1 knockout (KO) mice and they show a series of neurological and physical phenotypes that parallel some of the WBS features including facial dysmorphology, growth retardation, altered vocalization and anxiety responses, exploratory activity changes and motor coordination deficits. GTF2IRD1 is strongly expressed in the Purkinje neurons of the cerebellum and functional defects of these cells could explain the impaired motor coordination. As a means to understand the cellular defects that underpin the cognitive and behavioural changes in our mice, we chose to begin by examining the Purkinje neurons in detail. We have used calbindin immunofluorescence to study Purkinje neuron morphology and no major defects were identified. The Golgi silver impregnation technique was used to study Purkinje cell microanatomy in greater detail and we are in the process of quantifying the extent of dendritic branching and spine formation. We also use primary cell culture of isolated Purkinje neurons to study early neurite branching and we will test the function of KO Purkinje neurons using patch-clamp electrophysiology in live slice samples. High-resolution MRI analysis will also be employed to examine the overall anatomy, volumes and layers of the KO brains. These data, along with analysis of other Gtf2ird1-expressing cell types, will address the cellular basis of the cognitive and behavioural dysfunction in Gtf2ird1 KO mice and provide important clues regarding the role of GTF2IRD1 in WBS. Keywords: Ataxia, Williams-Beuren syndrome, mouse knockout, Purkinje neurons, GTF2IRD1 Conference: XII International Conference on Cognitive Neuroscience (ICON-XII), Brisbane, Queensland, Australia, 27 Jul - 31 Jul, 2014. Presentation Type: Poster Topic: Motor Behaviour Citation: Chang C, Canales C, Power J, Hannan A, Hardeman E and Palmer S (2015). Cellular neuropathology associated with cognitive and behavioural dysfunction in a mouse model of Williams-Beuren syndrome. Conference Abstract: XII International Conference on Cognitive Neuroscience (ICON-XII). doi: 10.3389/conf.fnhum.2015.217.00040 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 19 Feb 2015; Published Online: 24 Apr 2015. * Correspondence: Ms. Cecilia Chin Roei Chang, University of New South Wales, School of Medical Sciences, Sydney, Australia, cecilia.c.chang@student.unsw.edu.au Mr. Cesar Canales, Univeristy of New South Wales, School of Medical Sciences, Sydney, Australia, c.canalesmartinez@unsw.edu.au Dr. John Power, University of New South Wales, Translational Neuroscience Facility, Sydney, Australia, john.power@unsw.edu.au Prof. Anthony Hannan, The Florey Institute of Neuroscience and Mental Health, Neural Plasticity, Melbourne, Australia, anthony.hannan@florey.edu.au Prof. Edna Hardeman, Univeristy of New South Wales, School of Medical Sciences, Sydney, Australia, e.hardeman@unsw.edu.au Dr. Stephen Palmer, University of New South Wales, School of Medical Sciences, Sydney, Australia, s.palmer@unsw.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Cecilia Chin Roei Chang Cesar Canales John Power Anthony Hannan Edna Hardeman Stephen Palmer Google Cecilia Chin Roei Chang Cesar Canales John Power Anthony Hannan Edna Hardeman Stephen Palmer Google Scholar Cecilia Chin Roei Chang Cesar Canales John Power Anthony Hannan Edna Hardeman Stephen Palmer PubMed Cecilia Chin Roei Chang Cesar Canales John Power Anthony Hannan Edna Hardeman Stephen Palmer Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Hippocampal and striatal histomorphology following chronic nicotine administration in female and male rats.

Nicotine is a subject of continuous research because of its likely ameliorative effects on neurologic and neurodegenerative disorders. This study examined the effects of its chronic subcutaneous administration on hippocampal and striatal microstructure in both female and male rats. Forty adult female and male Wistar rats were divided into 4 groups. Three experimental groups were administered nicotine via subcutaneous injections at doses of 0.25, 2 and 4 mg/kg body weight for 28 days. Control groups received normal saline. Following administration, routine processing of brain tissues was carried out. Sections obtained were stained using routine H&E methods for general histological appearance, Cresyl violet methods for nissl substances, and Bielschwolsky silver impregnation method for neuritic plaques and neurofibrillary tangles. The study showed significant increase in percentage of neurons showing degenerating features in the hippocampus and striatum of both female and male rats following the higher doses of nicotine treatment. Only female rats showed positive agyrophilic (black-coloured) aggregations in the hippocampal and striatal regions after nicotine treatment. The present study indicates that higher dose of chronic nicotine administration may induce hippocampal and striatal neurodegenerative changes. However, further studies using more specific method for studying neurodegeneration within brain regions is recommended.

Экспериментальное обоснование ретрактильного механизма формирования диастаза пересеченных нервов и дополнение к методам его лечения

Relevance Mechanisms of formation and treatment of the interval space between stumps of sectioned nerve remain one of actual and poorly studied factors of formation of hypercollagen scar of nerve and nevroma. The purpose of the study The goal of the work is study of possibility of retraction of nerve fibers in formation of interval between stumps of sectioned nerve and an attempt at its inhibition. Materials and methods Signs of retraction of nerve fibers on human amputated extremities are studied with aid of silver impregnation of fixed preparations by Bielschowsky-Gros. For experimental study of regularities of contraction of myelinated and myelinles nerve fibers at their section there are used models of living preparations of vertebrate and invertebrate animals. With aid of phase-contrast computerized videomicroscopy, a possibility of participation of contraction of nerve fibers in an increase of space between stumps of sectioned nerve is studied. A possibility of medicament inhibition of this retraction with aid of blockers of cytoplasmic mobility is shown. Electrophysiological methods are used for study of effect of these substances on neuromembranes and a possibility of use of the tested blockers is checked in experiments of treatment of the whole animals. Results and their discussion On fixed histological preparations of nerves of damaged and amputated human extremities there are detected signs of contractile activities of nerve fibers. In experiments on isolated living fibers for the first time demonstrated is dynamics of the bidirectional retraction of myelinated nerve fibers, which accepts their participation in enlargement of diastasis of cross-sectioned nerves. On myelinles axons with preserved neuronal bodies there is studied action of blockers of contractile activity of the cytoplasm: nimodipine, cytochalasin, blebbistatin, and colchicine. There is proved participation in retraction of axons of the main protein polymers of the axoplasmic cytoskeleton and a possibility of use of these blockers for inhibition of posttraumatic retraction of nerve fibers. Electrophysiological experiments have shown a low toxicity of these agents and a possibility of their use for treatment of the traumatic diastasis of nerves in experiments on the whole animals. Conclusion 1. There is shown the capability for retraction in myelin nerve fibers of human and other vertebrates after transaction of nerves. 2. Based on experiments on living single neurons with preserved processes, a hypothesis is formulated about participation of active contraction of axons in mechanism of formation of diastasis. 3. There is analyzed the ability of several main blockers of the axoplasm motility: cytochalasin B, blebbistatin, colchicine, and nimodipine to stop traumatic retraction of neurites. 4. The absence is shown of pathological influences of the studied inhibitors on electrophysiological properties of the neuromembrane, which admits their use for treatment of diastasis at transaction of nerves in the whole experimental animals. Key words Nerve diastase, nervous fibres retraction, mechanism axoplasm retraction, axon retraction inhibitors

Histochemical Changes in the Cerebellum of Wistar Rats Administered with Oral Doses of Zidovudine

Zidovudine is a drugs used in the management of Human Immunodeficiency Virus (HIV) and Acquired Immunodeficiency Syndrome (AIDS) infection in sub-Saharan Africa in combination with other drugs. The objective of this research was to investigate the potential harmful effects of this drug on the histology of the cerebellum of Wistar rats. Twenty male Wistar rats were used for this study. The rats were divided into 2 groups of 10 rats each. Group A served as the control and was administered with 1 ml of distill water, while group B was administered with 8.57mg/kg of zidovudine daily for 30 days, after which the rats where sacrificed and each cerebellum was harvested, processed and stained using haematoxylin and Eosin (H/E), silver impregnation method. Paraffin impregnated Glial Fibrilar Acidic Protein (GFAP), Neuron Specific Enolase (NSE) and Neurofilament (NF) immunochemistry methods. Stained slides were viewed using light microscope. Results showed that, the cerebellum of Groups B animals were affected with moderate to severe shrinking and distortion of the Purkinje cells and granular cells, when compared with the control. Group B animals, also showed more expression of GFAP, NSE and NF staining in their cerebellum than the control. This suggests that zidovudine is harmful to the cerebellum and should be taken with caution