ULTRASTRUCTURE OF THE WALL OF THE TERMINAL VESSELS OF THE STOMACH MUCOSA

The infrastructure of the wall of the terminal gastric mucosa vessels (of Corpus and pars pylorica) of 15 adult rats was investigated. It was established that the number of fenestrated vessels as well as the degree of fenestration in direction to the glandular cells enhanced along with vascidar caliber increasing. While the thickness of the endothelial cells and the amount of their organelles reduced there was an elevation of the count and length of luminal evaginations. The basal membrane became thinner and the pericytes reduced in number. These alterations could be better established in the subepithelial vessels (mainly in the venous capillaries and postcapillary venules) which was more outlined in the pyloric region. The gastric mucosal veins were presented by venules without myocytes but with pericytes. Some arteries could be observed in the submucosa only. The fenestration was interpreted in the sense of possible participation in the ionic transport

Immunomorphological characteristics of pleomorphic adenoma of salivary glands

The immunohistochemical profile of 23 pleomorphic adenomas and 7 normal salivary glands was studied. We used antisera to vimentin (V), desmin (D), epithelial membrane antigen (EMA), prostate specific antigen (PSA), pancytokeratin, carcinoembryonic antigen (CEA), glial fibrillary acidic protein (GFAP) and S-100 protein. In the ducts and myoepithelial cells of normal salivary glands immunopositivity to most of the cytoskeletal proteins, EMA and CEA was observed. GFAP was localized only in cells of striated ducts. Major differences in the expression of various antigens among tubular structures, solid sheets, the myxoid and chondroid in the pleomorphic adenoma were encountered. Appearance of GFAP as a sign of stromal transformation into myxoid and chondroid was detected.Judging from these comparative immunohistochemical characteristics between normal salivary glands and pleomorphic adenomas, we assume that tumour cells originate from the reserve cells of intercalated and striated ducts.Nous avons étudié les caractéristiques immunohistochimiques de 23 adénomes pléomorphes et de 7 glandes salivaires non tumorales. Nous avons utilisé des anticorps pour la vimentine (V), la desmine (D), l’antigène de membrane épithéliale (EMA), antigène prostatique spécifique (PSA), la pancytokératine, l’antigène carcinoembryonnaire (CEA), la protéine gliale fibrillaire acide (GFAP) et la protéine S-100. Dans les canaux et dans les cellules myoépithéliales des glandes salivaires normales c’est l’immunopositivité pour la plupart des protéines du cytosquelette, EMA et CEA qui est observée. GFAP est localisée uniquement dans les cellules des canaux striés. Des différences majeures dans l’expression des divers antigènes ont été rencontrées dans les structures tubulaires, dans les nappes cellulaires et dans les portions myxoïdes et chondroïdes des adénomes pleomorphes. L’apparition de GFAP a été observée comme signe de transformation myxoïde ou chondroïde du stroma.En nous basant sur la comparaison des caractéristiques immunohistochimiques entre les glandes salivaires normales et les adénomes pléomorphes, nous supposons que les cellules tumorales trouvent leur origine dans les cellules de réserve des canaux intercalaires et des canaux striés.

Mitochondrial structure and function are not different between nonfailing donor and end‐stage failing human hearts

During human heart failure, the balance of cardiac energy use switches from predominantly fatty acids (FAs) to glucose. We hypothesized that this substrate shift was the result of mitochondrial degeneration; therefore, we examined mitochondrial oxidation and ultrastructure in the failing human heart by using respirometry, transmission electron microscopy, and gene expression studies of demographically matched donor and failing human heart left ventricular (LV) tissues. Surprisingly, respiratory capacities for failing LV isolated mitochondria (n = 9) were not significantly diminished compared with donor LV isolated mitochondria (n = 7) for glycolysis (pyruvate + malate)‐ or FA (palmitoylcarnitine)‐derived substrates, and mitochondrial densities, assessed via citrate synthase activity, were consistent between groups. Transmission electron microscopy images also showed no ultrastructural remodeling for failing vs. donor mitochondria; however, the fraction of lipid droplets (LDs) in direct contact with a mitochondrion was reduced, and the average distance between an LD and its nearest neighboring mitochondrion was increased. Analysis of FA processing gene expression between donor and failing LVs revealed 0.64‐fold reduced transcript levels for the mitochondrial‐LD tether, perilipin 5, in the failing myocardium (P = 0.003). Thus, reduced FA use in heart failure may result from improper delivery, potentially via decreased perilipin 5 expression and mitochondrial‐LD tethering, and not from intrinsic mitochondrial dysfunction.—Holzem, K. M., Vinnakota, K. C., Ravikumar, V. K., Madden, E. J., Ewald, G. A., Dikranian, K., Beard, D. A., Efimov, I. R. Mitochondrial structure and function are not different between nonfailing donor and end‐stage failing human hearts. FASEB J. 30, 2698‐2707 (2016). www.fasebj.orgPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154292/1/fsb2fj201500118r.pd

Zika virus infection in the developing mouse produces dramatically different neuropathology dependent on viral strain

Zika virus (ZIKV) infection during pregnancy has been causally linked to a constellation of neurodevelopmental deformities in the fetus resulting in a disease termed congenital Zika syndrome (CZS). Here we detail how ZIKV infection produces extensive neuropathology in the developing mouse brain and spinal cord of both sexes. Surprisingly, neuropathology differs depending on viral strain with a French Polynesian isolate producing primarily excitotoxicity and a Brazilian isolate being almost exclusively apoptotic but occurring over a prolonged period that is more likely to produce severe hypoplasia. We also show exposure can produce a characteristic pattern of infection that mirrors neuropathology and ultimately results in gross morphological deformities strikingly similar to CZS. This research provides a valuable mouse model mirroring the clinical course of disease that can be used to test potential therapies to improve treatment and gain a better understanding of the disabilities associated with CZS

Changes in synaptic transmission and protein expression in the brains of adult offspring after prenatal inhibition of the kynurenine pathway

During early brain development, N-methyl-d-aspartate (NMDA) receptors are involved in cell migration, neuritogenesis, axon guidance and synapse formation, but the mechanisms which regulate NMDA receptor density and function remain unclear. The kynurenine pathway of tryptophan metabolism includes an agonist (quinolinic acid) and an antagonist (kynurenic acid) at NMDA receptors and we have previously shown that inhibition of the pathway using the kynurenine-3-monoxygenase inhibitor Ro61-8048 in late gestation produces rapid changes in protein expression in the embryos and effects on synaptic transmission lasting until postnatal day 21 (P21). The present study sought to determine whether any of these effects are maintained into adulthood. After prenatal injections of Ro61-8048 the litter was allowed to develop to P60 when some offspring were euthanized and the brains removed for examination. Analysis of protein expression by Western blotting revealed significantly reduced expression of the GluN2A subunit (32%) and the morphogenetic protein sonic hedgehog (31%), with a 29% increase in the expression of doublecortin, a protein associated with neurogenesis. No changes were seen in mRNA abundance using quantitative real-time polymerase chain reaction. Neuronal excitability was normal in the CA1 region of hippocampal slices but paired-pulse stimulation revealed less inhibition at short interpulse intervals. The amount of long-term potentiation was decreased by 49% in treated pups and recovery after low-frequency stimulation was delayed. The results not only strengthen the view that basal, constitutive kynurenine metabolism is involved in normal brain development, but also show that changes induced prenatally can affect the brains of adult offspring and those changes are quite different from those seen previously at weaning (P21). Those changes may be mediated by altered expression of NMDAR subunits and sonic hedgehog

Distinct Temporal and Anatomical Distributions of Amyloid-β and Tau Abnormalities following Controlled Cortical Impact in Transgenic Mice

Traumatic brain injury (TBI) is a major environmental risk factor for Alzheimer's disease. Intracellular accumulations of amyloid-β and tau proteins have been observed within hours following severe TBI in humans. Similar abnormalities have been recapitulated in young 3xTg-AD mice subjected to the controlled cortical impact model (CCI) of TBI and sacrificed at 24 h and 7 days post injury. This study investigated the temporal and anatomical distributions of amyloid-β and tau abnormalities from 1 h to 24 h post injury in the same model. Intra-axonal amyloid-β accumulation in the fimbria was detected as early as 1 hour and increased monotonically over 24 hours following injury. Tau immunoreactivity in the fimbria and amygdala had a biphasic time course with peaks at 1 hour and 24 hours, while tau immunoreactivity in the contralateral CA1 rose in a delayed fashion starting at 12 hours after injury. Furthermore, rapid intra-axonal amyloid-β accumulation was similarly observed post controlled cortical injury in APP/PS1 mice, another transgenic Alzheimer's disease mouse model. Acute increases in total and phospho-tau immunoreactivity were also evident in single transgenic TauP301L mice subjected to controlled cortical injury. These data provide further evidence for the causal effects of moderately severe contusional TBI on acceleration of acute Alzheimer-related abnormalities and the independent relationship between amyloid-β and tau in this setting

Immediate, but Not Delayed, Microsurgical Skull Reconstruction Exacerbates Brain Damage in Experimental Traumatic Brain Injury Model

Moderate to severe traumatic brain injury (TBI) often results in malformations to the skull. Aesthetic surgical maneuvers may offer normalized skull structure, but inconsistent surgical closure of the skull area accompanies TBI. We examined whether wound closure by replacement of skull flap and bone wax would allow aesthetic reconstruction of the TBI-induced skull damage without causing any detrimental effects to the cortical tissue. Adult male Sprague-Dawley rats were subjected to TBI using the controlled cortical impact (CCI) injury model. Immediately after the TBI surgery, animals were randomly assigned to skull flap replacement with or without bone wax or no bone reconstruction, then were euthanized at five days post-TBI for pathological analyses. The skull reconstruction provided normalized gross bone architecture, but 2,3,5-triphenyltetrazolium chloride and hematoxylin and eosin staining results revealed larger cortical damage in these animals compared to those that underwent no surgical maneuver at all. Brain swelling accompanied TBI, especially the severe model, that could have relieved the intracranial pressure in those animals with no skull reconstruction. In contrast, the immediate skull reconstruction produced an upregulation of the edema marker aquaporin-4 staining, which likely prevented the therapeutic benefits of brain swelling and resulted in larger cortical infarcts. Interestingly, TBI animals introduced to a delay in skull reconstruction (i.e., 2 days post-TBI) showed significantly reduced edema and infarcts compared to those exposed to immediate skull reconstruction. That immediate, but not delayed, skull reconstruction may exacerbate TBI-induced cortical tissue damage warrants a careful consideration of aesthetic repair of the skull in TBI

Effects of Ethanol and NAP on Cerebellar Expression of the Neural Cell Adhesion Molecule L1

The neural cell adhesion molecule L1 is critical for brain development and plays a role in learning and memory in the adult. Ethanol inhibits L1-mediated cell adhesion and neurite outgrowth in cerebellar granule neurons (CGNs), and these actions might underlie the cerebellar dysmorphology of fetal alcohol spectrum disorders. The peptide NAP potently blocks ethanol inhibition of L1 adhesion and prevents ethanol teratogenesis. We used quantitative RT-PCR and Western blotting of extracts of cerebellar slices, CGNs, and astrocytes from postnatal day 7 (PD7) rats to investigate whether ethanol and NAP act in part by regulating the expression of L1. Treatment of cerebellar slices with 20 mM ethanol, 10−12 M NAP, or both for 4 hours, 24 hours, and 10 days did not significantly affect L1 mRNA and protein levels. Similar treatment for 4 or 24 hours did not regulate L1 expression in primary cultures of CGNs and astrocytes, the predominant cerebellar cell types. Because ethanol also damages the adult cerebellum, we studied the effects of chronic ethanol exposure in adult rats. One year of binge drinking did not alter L1 gene and protein expression in extracts from whole cerebellum. Thus, ethanol does not alter L1 expression in the developing or adult cerebellum; more likely, ethanol disrupts L1 function by modifying its conformation and signaling. Likewise, NAP antagonizes the actions of ethanol without altering L1 expression

Alcohol Exposure Decreases CREB Binding Protein Expression and Histone Acetylation in the Developing Cerebellum

Fetal alcohol exposure affects 1 in 100 children making it the leading cause of mental retardation in the US. It has long been known that alcohol affects cerebellum development and function. However, the underlying molecular mechanism is unclear.We demonstrate that CREB binding protein (CBP) is widely expressed in granule and Purkinje neurons of the developing cerebellar cortex of naïve rats. We also show that exposure to ethanol during the 3(rd) trimester-equivalent of human pregnancy reduces CBP levels. CBP is a histone acetyltransferase, a component of the epigenetic mechanism controlling neuronal gene expression. We further demonstrate that the acetylation of both histone H3 and H4 is reduced in the cerebellum of ethanol-treated rats.These findings indicate that ethanol exposure decreases the expression and function of CBP in the developing cerebellum. This effect of ethanol may be responsible for the motor coordination deficits that characterize fetal alcohol spectrum disorders