Home About us Contact
|
Home About us Contact | ||
|
|
||
Histochemistry
Kinds of Histochemistry Selected AbstractsDevelopment of axonal pathways in the human fetal fronto-limbic brain: histochemical characterization and diffusion tensor imagingJOURNAL OF ANATOMY, Issue 4 2010Lana Vasung Abstract The development of cortical axonal pathways in the human brain begins during the transition between the embryonic and fetal period, happens in a series of sequential events, and leads to the establishment of major long trajectories by the neonatal period. We have correlated histochemical markers (acetylcholinesterase (AChE) histochemistry, antibody against synaptic protein SNAP-25 (SNAP-25-immunoreactivity) and neurofilament 200) with the diffusion tensor imaging (DTI) database in order to make a reconstruction of the origin, growth pattern and termination of the pathways in the period between 8 and 34 postconceptual weeks (PCW). Histological sections revealed that the initial outgrowth and formation of joined trajectories of subcortico-frontal pathways (external capsule, cerebral stalk,internal capsule) and limbic bundles (fornix, stria terminalis, amygdaloid radiation) occur by 10 PCW. As early as 11 PCW, major afferent fibers invade the corticostriatal junction. At 13,14 PCW, axonal pathways from the thalamus and basal forebrain approach the deep moiety of the cortical plate, causing the first lamination. The period between 15 and 18 PCW is dominated by elaboration of the periventricular crossroads, sagittal strata and spread of fibers in the subplate and marginal zone. Tracing of fibers in the subplate with DTI is unsuccessful due to the isotropy of this zone. Penetration of the cortical plate occurs after 24,26 PCW. In conclusion, frontal axonal pathways form the periventricular crossroads, sagittal strata and ,waiting' compartments during the path-finding and penetration of the cortical plate. Histochemistry is advantageous in the demonstration of a growth pattern, whereas DTI is unique for demonstrating axonal trajectories. The complexity of fibers is the biological substrate of selective vulnerability of the fetal white matter. [source] Growth and Differentiation of Osteoblast-Like Cells from Calvaria of Connexin43 Deficient MiceMATERIALWISSENSCHAFT UND WERKSTOFFTECHNIK, Issue 12 2004M. Wiemann Osteoblasten-artige Zellen; Connexin43-defiziente Mäuse; gap junctions; Differenzierung Abstract Extensive cell-cell-coupling via gap junctions has been suspected to play an essential role for osteoblast development. Here, osteoblast-like cells (OBL) from connexin(Cx)43 knock out mice were used to explore the role of Cx43 for osteoblast differentiation. Primary cultures of OBL were derived from calvaria of homozygous (Cx43-/-) and heterozygous (Cx43+/,) knock out mice and also from wild type controls (Cx43+/+). In Cx43-/- OBL Lucifer Yellow dye coupling was largely abolished demonstrating that small molecules could no longer be transferred among neighboring cells. Cx43-/- OBL grew out very slowly from calvarial fragments. Nevertheless their cell density around explants was increased 3-fold vs. controls after 3 weeks. Histochemistry showed that in many Cx43-/- OBL there was an increased alkaline phosphatase activity within the cytoplasm and close to the cell membrane. Mineralization was diminished in Cx43-/- cultures. In heterozygous Cx43+/, OBL all aforementioned effects were less pronounced, pointing to a gene-dosage effect. Data suggest that the loss of Cx43 indirectly impairs the osteoblastic phenotype, e.g. by disturbing cellular functions such as motility and/or secretion. If this holds true, all parameters in the interphase of enosseous implants which lower gap junction expression will also affect bone regeneration. Wachstum und Differenzierung von Osteoblasten-artigen Zellen aus Kalvarien Connexin43-defizienter Mäuse Es wurde oft vermutet, dass die ausgeprägte Zell-Zell-Kopplung von Osteoblasten durch gap junctions eine besondere Rolle für die Differenzierung der gekoppelten Zellen spielt. In dieser Arbeit wurden daher Osteoblasten-artige Zellen (OBL) aus Connexin43 (Cx43) knock out Mäusen benutzt, um die Bedeutung von Cx43-gap-junction-Kanälen für die Differenzierung von Osteoblasten zu untersuchen. Die dafür notwendigen OBL-Primärkulturen wurden aus Calvarienfragmenten von homozygoten (Cx43-/-) und heterozygoten (Cx43+/,) knock out Mäusen sowie aus Wildtyp-Mäusen gewonnen. In Cx43-/- OBL war die Lucifer Yellow-Farbstoffkopplung weitgehend aufgehoben. Dieser Befund zeigt, dass Moleküle ,600 D zwischen Cx43-/- Zellen kaum noch ausgetauscht werden können. Cx43-/- Zellen wuchsen vergleichsweise langsam aus ihren Calvarienfragmenten aus. Dennoch erreichten diese Kulturen nach 3 Wochen eine im Vergleich zur Kontrolle 3fach höhere Zelldichte. Histochemisch zeigte sich, dass in Cx43-/- Zellen die alkalische Phosphatase-Aktivität im Zytoplasma und besonders im Bereich der Zellmembran erhöht war. Die Mineralisierung war hingegen herabgesetzt. In heterozygoten Cx43+/, OBL waren alle genannten Effekte intermediär ausgeprägt, was auf einen Gen-Dosis-Effekt deutet. Insgesamt legen die Befunde nahe, dass der Verlust von Cx43 die Ausprägung des osteoblastären Phänotyps, z.,B. durch eine Behinderung der Zellbeweglichkeit und/oder der Sekretion beeinträchtigt. Daher dürften alle Parameter, die die Expression von Cx43 im Interphase eines enossalen Implantats stören, die Knochenregeneration behindern. [source] The Prenatal Development and Histochemistry of the Ileal Mucins in the Bovine FetusesANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2009F. Beyaz Summary Few studies exist regarding the distribution of intestinal mucins in fetuses of mammalians such as cattle and sheep. In this study, we aimed to describe the changes in the mucin production by ileal epithelium of bovine fetuses during their prenatal development. The goblet cells showed heterogeneity in mucins and the apical cytoplasm of the enterocytes demonstrated Periodic acid Schiff-positive reaction which declined gradually towards the birth. Moreover, the number of the goblet cells containing acidic and mixed mucins augmented, whereas those containing neutral mucins decreased with advancing gestational age. After sixth month of gestation, with the initiation of the ileal Peyer patches and follicle-associated epithelium development, a gradual increase in the number of goblet cells containing sulfomucins was also noticed towards the birth. The presence of different mucins in the ileum of bovine fetuses throughout prenatal development might play a role in the protection of the intestinal mucosa against urinary waste products in swallowed amniotic fluid and bile. Furthermore, mucins can also contribute for the formation of meconium in intra-uterine life and building of strong intestinal barrier with predominating sulfomucins, protecting the intestine against potential pathogens and digestive enzymes after birth. [source] Histology and Mucin Histochemistry of The Digestive Tract of Yellow Catfish, Pelteobagrus fulvidracoANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 4 2009X. J. Cao Summary The histology and characteristics of mucins secreted by epithelial mucous cells of the digestive tract in yellow catfish, Pelteobagrus fulvidraco were investigated using light microscope and transmission electron microscope. The digestive tract was divided into a pharynx, oesophagus, U-shaped stomach (with a cardiac, fundic and pyloric part) and intestine, composed of anterior intestine, middle intestine and posterior intestine, which consisted of a mucosa (epithelial layer), lamina propria-submucosa, muscularis and serosa. A large number of isolated longitudinal striated muscular bundles were present in the lamina propria-submucosa of pharynx. Goblet cells were observed throughout the digestive tract, except in the stomach. In the cardiac and fundic stomach, a plenty of gastric glands were observed, whereas they were absent in the pyloric part. Numerous mitochondria and endoplasmic reticulum were observed in the columnar epithelial cells of the intestine, especially of the anterior part. The epithelial mucous cells contained neutral or other two mixtures of acid and neutral mucins, the first being the most common. The neutral mucin was the only type of mucins in the stomach, anterior intestine and middle intestine. The results of this study will be helpful for understanding the digestive physiology and diagnosing some gastrointestinal diseases in yellow catfish. [source] Mucous Cells in Micropogonias furnieri gills: Histochemistry and UltrastructureANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2001A. O. Díaz The characteristics of the mucous cells located in the gills of the fish Micropogonias furnieri were investigated. Using histochemical procedures that included methods for localization and characterization of glycoproteins (GPs), no differences were detected between the mucous cell contents of the primary and secondary lamellae. The GPs were identified with (a) oxidizable vecinal diols; (b) sialic acids and some of their chain variants, C7 or C9; (c) carboxyl groups and (d) sulphate groups. The electron microscope showed large mucous globules of different electro densities from mucous cells located deep in the epithelium between the other epithelial cells; the release of mucus by exocytosis was observed. GPs secreted on the surface of the mucous cells was suggested to be important for the lubrication, protection and inhibition of micro-organisms. It is possibility that GPs could have similar roles in Micropogonias furnieri gills. [source] Is the mitochondrial complex I ND5 gene a hot-spot for MELAS causing mutations?ANNALS OF NEUROLOGY, Issue 1 2003Danae Liolitsa PhD We identified two novel heteroplasmic mitochondrial DNA point mutations in the gene encoding the ND5 subunit of complex I: a 12770A,G transition identified in a patient with MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes) and a 13045A,C transversion in a patient with a MELAS/Leber's hereditary optic neuropathy/Leigh's overlap syndrome. Biochemical analysis of muscle homogenates showed normal or very mildly reduced complex I activity. Histochemistry was normal. Our observations add to the evidence that mitochondrial ND5 protein coding gene mutations frequently associate with the MELAS phenotype, and it highlights the role of complex I dysfunction in MELAS. Ann Neurol 2003 [source] A new type of minocycline-induced cutaneous hyperpigmentationCLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 1 2004R. W. Mouton Summary Pigmentary disorders are recognized adverse effects of the semi-synthetic tetracycline derivative antibiotic, minocycline. Three distinct types of minocycline-induced cutaneous pigmentation have been described. Type I, blue,black pigmentation confined to sites of scarring or inflammation on the face; Type II, blue,grey circumscribed pigmentation of normal skin of the lower legs and forearms; and Type III, diffuse muddy brown pigmentation of normal skin accentuated in sun-exposed areas. We report two patients with acne vulgaris with a fourth type of minocycline-induced cutaneous pigmentation. They presented with circumscribed blue,grey pigmentation within acne scars confined to the back. Histology showed pigment within dendritic cells, and extracellularly throughout the dermis. Histochemistry identified a calcium containing melanin-like substance. Iron was absent. Immunohistochemistry confirmed some pigment-containing cells to be macrophages. Electron microscopy demonstrated electron-dense granules, free and membrane-bound, within macrophages and fibroblast-like cells. Energy-dispersive X-ray analysis confirmed the presence of calcium. Iron was absent. This fourth type of cutaneous minocycline hyperpigmentation may be a variant of Type I, but based on clinical, pathological and microanalytical differences, appears to be a new entity. The pigment may be a drug metabolite,protein complex chelated with calcium, or an insoluble minocycline,melanin complex. We propose a classification of cutaneous minocycline pigmentation based on clinico-pathological criteria. [source] Mesothelioma Symposium 11.30,12.30 Tuesday 16 September 2003CYTOPATHOLOGY, Issue 2003Darrel Whitaker Dr The diagnosis of malignant mesothelioma on the cytology of serous effusions is a two-phase process. First is to determine that the effusion is malignant based on morphological features such as a highly cellular fluid with many large three dimensional cell aggregates, and/or the recognition of minor malignant criteria including prominent cell engulfment, uniformly present very prominent nucleoli, or the finding of very large (giant) cells. In cell block sections, strong positive staining with EMA often with cell membrane accentuation provides compelling support for a cytological diagnosis of malignancy. Second is to recognize that the malignant cells have a mesothelial phenotype and do not represent metastatic malignancy (usually adenocarcinoma). Criteria in support of mesothelioma include the lack of a ,two cell' population, that is one native (mesothelial) and one foreign (metastatic), cells with abundant dense staining cytoplasm, the presence of ,windows' where mesothelioma cells lie in close apposition and intracytoplasmic glycogen presenting either as small peripheral vacuoles on MGG stained smears or large yellow refractile crescents on Papanicolaou stained smears. In addition, mesothliomas often possess connective tissue stromal cores occurring as either well-formed collagen within papillary aggregates or lying free as pink (MGG) or light green (Pap) amorphous material in the background of the smear or in loose association with mesothelioma cells. Finally small orange staining squamous-like cells can occasionally be identified and sometimes this may be a very prominent finding and has resulted in the false impression of a squamous cell carcinoma. Almost certainly these cells represent apoptotic tumour cells. The connective tissue mucin hyaluronic acid may be found as a net-like pattern in the smear background or as large hard-edged magenta-stained vacuoles on MGG-stained smears. Cell block sections provide architectural information and it is usually possible to separate mesothelioma aggregates with their cuboidal cells, central nuclei and abundant dense cytoplasm arranged in solid, papillary or hollow clusters from those of adenocarcinoma with less dense, often foamy cytoplasm, often composed of columnar cells with elongated nuclei. Aggregate form in adenocarcinoma can be variable but true acini are a rare finding. These cell block sections provide an ideal medium for histochemistry (PAS with and without diastase digestion) and immunocytochemistry. By using a panel of antibodies (Calretinin and CK 5/6, BerEp4, CEA, B72.3) it is almost always possible to distinguish mesothelioma from metastatic adenocarcinoma. Calretinin and CK 5/6 positive staining and absent staining with BerEp4, CEA and B72.3 is considered diagnostic of mesothelioma. [source] Chick limbs with mouse teeth: An effective in vivo culture system for tooth germ development and analysisDEVELOPMENTAL DYNAMICS, Issue 1 2003Eiki Koyama Abstract Mouse tooth germ development is currently studied by three main approaches: in wild-type and mutant mouse lines, after transplantation of tooth germs to ectopic sites, and in organ culture. The in vivo approaches are the most physiological but do not provide accessibility to tooth germs for further experimental manipulation. Organ cultures, although readily accessible, do not sustain full tooth germ development and are appropriate for short-term analysis. Thus, we sought to establish a new approach that would combine experimental accessibility with sustained development. We implanted fragments of embryonic day 12 mouse embryo first branchial arch containing early bud stage tooth germs into the lateral mesenchyme of day 4,5 chick embryo wing buds in ovo. Eggs were reincubated, and implanted tissues were examined by histochemistry and in situ hybridization over time. The tooth germs underwent seemingly normal growth, differentiation, and morphogenesis. They reached the cap, bell, and crown stages in approximately 3, 6, and 10 days, respectively, mimicking in a striking manner native temporal patterns. To examine mechanisms regulating tooth germ development, we first implanted tooth germ fragments, microinjected them with neutralizing antibodies to the key signaling molecule Sonic hedgehog (Shh), and examined them over time. Tooth germ development was markedly delayed, as revealed by poor morphogenesis and lack of mature ameloblasts and odontoblasts displaying characteristic traits such as an elongated cell shape, nuclear relocalization, and amelogenin gene expression. These phenotypic changes began to be reversed upon further incubation. The data show that the limb bud represents an effective, experimentally accessible as well as economical system for growth and analysis of developing tooth germs. The inhibitory effects of Shh neutralizing antibody treatment are discussed in relation to roles of this signaling pathway proposed by this and other groups previously. © 2002 Wiley-Liss, Inc. [source] Social experience organizes parallel networks in sensory and limbic forebrainDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2007Eun-Jin Yang Abstract Successful social behavior can directly influence an individual's reproductive success. Therefore, many organisms readily modify social behavior based on past experience. The neural changes induced by social experience, however, remain to be fully elucidated. We hypothesize that social modulation of neural systems not only occurs at the level of individual nuclei, but also of functional networks, and their relationships with behavior. We used the green anole lizard (Anolis carolinensis), which displays stereotyped, visually triggered social behaviors particularly suitable for comparisons of multiple functional networks in a social context, to test whether repeated aggressive interactions modify behavior and metabolic activity in limbic,hypothalamic and sensory forebrain regions, assessed by quantitative cytochrome oxidase (a slowly accumulating endogenous metabolic marker) histochemistry. We found that aggressive interactions potentiate aggressive behavior, induce changes in activities of individual nuclei, and organize context-specific functional neural networks. Surprisingly, this experiential effect is not only present in a limbic,hypothalamic network, but also extends to a sensory forebrain network directly relevant to the behavioral expression. Our results suggest that social experience modulates organisms' social behavior via modifying sensory and limbic neural systems in parallel both at the levels of individual regions and networks, potentially biasing perceptual as well as limbic processing. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007 [source] Histology, histochemistry and morphometry of the ovary of the adult plains viscacha (Lagostomus maximus) in different reproductive stagesACTA ZOOLOGICA, Issue 4 2009Mirta Alicia Flamini Abstract Lagostomus maximus is a South American Hystricognathi rodent whose reproductive behaviour shows characteristics unusual for mammals, such as polyovulation (200,800 oocytes) and a high rate of embryo mortality. Thirty-six mature females captured in the province of Buenos Aires showed different physiological reproductive stages. Most of them presented a postpartum oestrus in August,September. This characteristic is different from that reported in other geographical areas. The stages considered were: anoestrus, follicular phase, early pregnancy and late pregnancy. The ovaries were light-pink and smooth and presented a tortuous cord-like aspect. Many primordial follicles were found in all the females studied. Follicles in different states of maturation and primary and accessory corpora lutea were observed in the cortex. These structures were smaller than those present in other related species. Follicles did not project into the surface of the organ. Calcified follicles of diverse size were found in all the ovaries. Atretic follicles were found in all the stages analysed. Interstitial tissue surrounding the follicles and the corpora lutea was also observed. The number and proportion of different cortical structures varied in the physiological stages analysed. The ovaries of the viscacha have differential characteristics in comparison to other Hystricognathi, some of them related to polyovulation. [source] Lysosomal storage disease in Sida carpinifolia toxicosis: an induced mannosidosis in horsesEQUINE VETERINARY JOURNAL, Issue 5 2003A. P. LORETTI Summary Reasons for performing study: This study reports a neurological disease unrecognised until now in ponies in southern Brazil. Hypothesis: Epidemiological data strongly suggests that the ingestion of Sida carpinifolia is involved in the aetiology. We tested the hypothesis that it is an acquired lyosomal storage disease. Methods: Following the death of 3 ponies, all ponies from the premises were closely monitored; epidemiological data and clinical findings carefully recorded. Fragments of several organs, including CNS, were fixed in neutral formalin and embedded in paraffin-wax. Sections were stained with haematoxylin and eosin. Representative sections of the cerebellum and trigeminal ganglia were submitted to lectin histochemical procedures. Results: The neurological disorder, characterised by stiff gait, muscle tremors, abdominal pain and death, was observed on a farm with 3 hectares of pasture. Three of 11 ponies died 15,20 days after they had been introduced into a new paddock heavily infested by the plant Sida carpinifolia. No significant gross lesions were observed. The main histological findings included multiple cytoplasmatic vacuoles in swollen neurones in the brain, cerebellum, spinal cord, autonomic ganglia (trigeminal and celiac ganglia), and submucosal and myenteric plexus of the intestines. In the kidneys, there was marked vacuolation of the proximal convoluted tubular cells. Sections of cerebellum and trigeminal ganglion were submitted to lectin histochemistry. The vacuoles in different cerebellar and ganglion cells reacted strongly to the following lectins: Concanavalia ensiformis, Triticum vulgaris and succinylated- Triticum vulgaris. Conclusions: The pattern of staining coincides with that of both swainsonine toxicosis and inherited mannosidosis reports. The histopathological changes were similar to those described in S. carpinifolia spontaneous and experimental poisoning in goats. This disease seems to be similar to Swainsona, Oxytropis and Astragalus toxicosis. Potential relevance: S. carpinifolia should be evaluated as a possible cause in the diagnosis of equine neuropathies. [source] Altered membrane glycoprotein targeting in cholestatic hepatocytesEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 5 2010Giuseppa Esterina Liquori Eur J Clin Invest 2010; 40 (5): 393,400 Abstract Background, Hepatocytes are polarized epithelial cells with three morphologically and functionally distinct membrane surfaces: the sinusoidal, lateral and canalicular surface domains. These domains differ from each other in the expression of integral proteins, which concur to their polarized functions. We hypothesize that the cholestasis-induced alterations led to partial loss of hepatocyte polarity. An altered expression of membrane proteins may be indicative of functional disorders. Alkaline liver phosphatase (ALP), one of the most representative plasma membrane glycoproteins in hepatocytes, is expressed at the apical (canalicular) pole of the cell. Because the release of ALP protein in the bloodstream is significantly increased in cholestasis, the enzymatic levels of plasma ALP have major relevance in the diagnosis of cholestatic diseases. Here we assess the cholestasis-induced redistribution of membrane glycoproteins to investigate the ALP release. Materials and methods, We performed enzymatic histochemistry, immunohistochemistry, lectin histochemistry, immunogold and lectin-and immunoblotting studies. Experimental cholestasis was induced in rats by ligation of common bile duct (BDL). Results, The BDL led to altered membrane sialoglycoprotein targeting as well as to ultrastructural and functional disorders. Disarrangement of the microtubular system, thickening of the microfilamentous pericanalicular ectoplasm and disturbance of the vectorial trafficking of membrane glycoprotein containing vesicles were found. Conclusions, Altogether, results indicate that the cholestasis-induced partial loss of hepatocyte cell polarity leads to mistranslocation of ALP to the sinusoidal plasma membrane from where the enzyme is then massively released into the bloodstream. [source] Glutamatergic neurons are present in the rat ventral tegmental areaEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2007Tsuyoshi Yamaguchi Abstract The ventral tegmental area (VTA) is thought to play an important role in reward function. Two populations of neurons, containing either dopamine (DA) or ,-amino butyric acid (GABA), have been extensively characterized in this area. However, recent electrophysiological studies are consistent with the notion that neurons that utilize neurotransmitters other than DA or GABA are likely to be present in the VTA. Given the pronounced phenotypic diversity of neurons in this region, we have proposed that additional cell types, such as those that express the neurotransmitter glutamate may also be present in this area. Thus, by using in situ hybridization histochemistry we investigated whether transcripts encoded by genes for the two vesicular glutamate transporters, VGluT1 or VGluT2, were expressed in the VTA. We found that VGluT2 mRNA but not VGluT1 mRNA is expressed in the VTA. Neurons expressing VGluT2 mRNA were differentially distributed throughout the rostro-caudal and medio-lateral aspects of the VTA, with the highest concentration detected in rostro-medial areas. Phenotypic characterization with double in situ hybridization of these neurons indicated that they rarely co,expressed mRNAs for tyrosine hydroxylase (TH, marker for DAergic neurons) or glutamic acid decarboxylase (GAD, marker for GABAergic neurons). Based on the results described here, we concluded that the VTA contains glutamatergic neurons that in their vast majority are clearly non-DAergic and non-GABAergic. [source] Dopaminergic regulation of orexin neuronsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2005Michael Bubser Abstract Orexin/hypocretin neurons in the lateral hypothalamus and adjacent perifornical area (LH/PFA) innervate midbrain dopamine (DA) neurons that project to corticolimbic sites and subserve psychostimulant-induced locomotor activity. However, it is not known whether dopamine neurons in turn regulate the activity of orexin cells. We examined the ability of dopamine agonists to activate orexin neurons in the rat, as reflected by induction of Fos. The mixed dopamine agonist apomorphine increased Fos expression in orexin cells, with a greater effect on orexin neurons located medial to the fornix. Both the selective D1-like agonist, A-77636, and the D2-like agonist, quinpirole, also induced Fos in orexin cells, suggesting that stimulation of either receptor subtype is sufficient to activate orexin neurons. Consistent with this finding, combined SCH 23390 (D1 antagonist),haloperidol (D2 antagonist) pretreatment blocked apomorphine-induced activation of medial as well as lateral orexin neurons; in contrast, pretreatment with either the D1-like or D2-like antagonists alone did not attenuate apomorphine-induced activation of medial orexin cells. In situ hybridization histochemistry revealed that LH/PFA cells rarely express mRNAs encoding dopamine receptors, suggesting that orexin cells are transsynaptically activated by apomorphine. We therefore lesioned the nucleus accumbens, a site known to regulate orexin cells, but this treatment did not alter apomorphine-elicited activation of medial or lateral orexin neurons. Interestingly, apomorphine failed to activate orexin cells in isoflurane-anaesthetized animals. These data suggest that apomorphine-induced arousal but not accumbens-mediated hyperactivity is required for dopamine to transsynaptically activate orexin neurons. [source] Sexually dimorphic effects of hippocampal cholinergic deafferentation in ratsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2004Zachariah Jonasson Abstract To determine whether the basal forebrain-hippocampal cholinergic system supports sexually dimorphic functionality, male and female Long-Evans rats were given either selective medial septum/vertical limb of the diagonal band (MS/VDB) cholinergic lesions using the neurotoxin 192 IgG-saporin or a control surgery and then postoperatively tested in a set of standard spatial learning tasks in the Morris water maze. Lesions were highly specific and effective as confirmed by both choline acetyltransferase/parvalbumin immunostaining and acetylcholinesterase histochemistry. Female controls performed worse than male controls in place learning and MS/VDB lesions failed to impair spatial learning in male rats, both consistent with previous findings. In female rats, MS/VDB cholinergic lesions facilitated spatial reference learning. A subsequent test of learning strategy in the water maze revealed a female bias for a response, relative to a spatial, strategy; MS/VDB cholinergic lesions enhanced the use of a spatial strategy in both sexes, but only significantly so in males. Together, these results indicate a sexually dimorphic function associated with MS/VDB-hippocampal cholinergic inputs. In female rats, these neurons appear to support sex-specific spatial learning processes. [source] N -methyl- d -aspartate-triggered neuronal death in organotypic hippocampal cultures is endocytic, autophagic and mediated by the c-Jun N-terminal kinase pathwayEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2003Tiziana Borsello Abstract Acute excitotoxic neuronal death was studied in rat organotypic hippocampal slices exposed to 100 µmN -methyl- d -aspartate. Fulgurant death of pyramidal neurons occurred in the CA1 and CA3 regions and was already detectable within 2 h of the N-methyl- d -aspartate administration. Morphologically, the neuronal death was neither apoptotic nor necrotic but had the hallmarks of autophagic neuronal death, as shown by acid phosphatase histochemistry in both CA1 and CA3 and by electron microscopy in CA1. The dying neurons also manifested strong endocytosis of horseradish peroxidase or microperoxidase, occurring probably by a fluid phase mechanism, and followed, surprisingly, by nuclear entry. In addition to these autophagic and endocytic characteristics, there were indications that the c-Jun N-terminal kinase pathway was activated. Its target c-Jun was selectively phosphorylated in CA1, CA3 and the dentate gyrus and c-Fos, the transcription of which is under the positive control of c-Jun N-terminal kinase target Elk1, was selectively up-regulated in CA1 and CA3. All these effects, the neuronal death itself and the associated autophagy and endocytosis, were totally prevented by a cell-permeable inhibitor of the interaction between c-Jun N-terminal kinase and certain of its targets. These results show that pyramidal neurons undergoing excitotoxic death in this situation are autophagic and endocytic and that both the cell death and the associated autophagy and endocytosis are under the control of the c-Jun N-terminal kinase pathway. [source] Differential galanin receptor-1 and galanin expression by 5-HT neurons in dorsal raphé nucleus of rat and mouse: evidence for species-dependent modulation of serotonin transmissionEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 3 2003Jari A. Larm Abstract Galanin and galanin receptors are widely expressed by neurons in rat brain that either synthesize/release and/or are responsive to, classical transmitters such as ,-aminobutyric acid, acetylcholine, noradrenaline, histamine, dopamine and serotonin (5-hydroxytryptamine, 5-HT). The dorsal raphé nucleus (DRN) contains , 50% of the 5-HT neurons in the rat brain and a high percentage of these cells coexpress galanin and are responsive to exogenous galanin in vitro. However, the precise identity of the galanin receptor(s) present on these 5-HT neurons has not been previously established. Thus, the current study used a polyclonal antibody for the galanin receptor-1 (GalR1) to examine the possible expression of this receptor within the DRN of the rat and for comparative purposes also in the mouse. In the rat, intense GalR1-immunoreactivity (IR) was detected in a substantial population of 5-HT-immunoreactive neurons in the DRN, with prominent receptor immunostaining associated with soma and proximal dendrites. GalR1-IR was also observed in many cells within the adjacent median raphé nucleus. In mouse DRN, neurons exhibited similar levels and distribution of 5-HT-IR to that in the rat, but GalR1-IR was undetectable. Consistent with this, galanin and GalR1 mRNA were also undetectable in mouse DRN by in situ hybridization histochemistry, despite the detection of GalR1 mRNA (and GalR1-IR) in adjacent cells in the periaqueductal grey and other midbrain areas. 5-HT neuron activity in the DRN is primarily regulated via 5-HT1A autoreceptors, via inhibition of adenylate cyclase and activation of inward-rectifying K+ channels. Notably, the GalR1 receptor subtype signals via identical mechanisms and our findings establish that galanin modulates 5-HT neuron activity in the DRN of the rat via GalR1 (auto)receptors. However, these studies also identify important species differences in the relationship between midbrain galanin and 5-HT systems, which should prompt further investigations in relation to comparative human neurochemistry and which have implications for studies of animal models of relevant neurological conditions such as stress, anxiety and depression. [source] Short exposure to high levels of fluoride induces stage-dependent structural changes in ameloblasts and enamel mineralizationEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 2006D. M. Lyaruu We tested the hypothesis that the sensitivity of forming dental enamel to fluoride (F,) is ameloblast developmental stage-dependent and that enamel mineralization disturbances at the surface of fluorotic enamel are caused by damage to late-secretory- and transitional-stage ameloblasts. Four-day-old hamsters received a single intraperitoneal dose of 2.5,20 mg NaF/kg body weight and were examined, 24 h later, by histology and histochemistry. A single dose of ,,5 mg of NaF/kg induced the formation of a hyper- followed by a hypomineralized band in the secretory enamel, without changing the ameloblast structure. At 10 mg of NaF/kg, cystic lesions became apparent under isolated populations of distorted late-secretory- and transitional-stage ameloblasts. Staining with von Kossa stain showed that the enamel under these lesions was hypermineralized. At 20 mg of NaF/kg, cystic lesions containing necrotic cells were also found in the early stages of secretory amelogenesis and were also accompanied with hypermineralization of the enamel surface. We concluded that the sensitivity to F, is ameloblast developmental stage-dependent. Groups of transitional ameloblasts are most sensitive, followed by those at early secretory stages. These data suggest that a F-induced increase in cell death in the transitional-stage ameloblasts accompanies the formation of cystic lesions, which may explain the formation of enamel pits seen clinically in erupted teeth. [source] Treatment of neutral glycosphingolipid lysosomal storage diseases via inhibition of the ABC drug transporter, MDR1FEBS JOURNAL, Issue 9 2006Cyclosporin A can lower serum, liver globotriaosyl ceramide levels in the Fabry mouse model We have shown that the ABC transporter, multiple drug resistance protein 1 (MDR1, P-glycoprotein) translocates glucosyl ceramide from the cytosolic to the luminal Golgi surface for neutral, but not acidic, glycosphingolipid (GSL) synthesis. Here we show that the MDR1 inhibitor, cyclosporin A (CsA) can deplete Gaucher lymphoid cell lines of accumulated glucosyl ceramide and Fabry cell lines of globotriaosyl ceramide (Gb3), by preventing de novo synthesis. In the Fabry mouse model, Gb3 is increased in the heart, liver, spleen, brain and kidney. The lack of renal glomerular Gb3 is retained, but the number of verotoxin 1 (VT1)-staining renal tubules, and VT1 tubular targeting in vivo, is markedly increased in Fabry mice. Adult Fabry mice were treated with ,-galactosidase (enzyme-replacement therapy, ERT) to eliminate serum Gb3 and lower Gb3 levels in some tissues. Serum Gb3 was monitored using a VT1 ELISA during a post-ERT recovery phase ± biweekly intra peritoneal CsA. After 9 weeks, tissue Gb3 content and localization were determined using VT1/TLC overlay and histochemistry. Serum Gb3 recovered to lower levels after CsA treatment. Gb3 was undetected in wild-type liver, and the levels of Gb3 (but not gangliosides) in Fabry mouse liver were significantly depleted by CsA treatment. VT1 liver histochemistry showed Gb3 accumulated in Kupffer cells, endothelial cell subsets within the central and portal vein and within the portal triad. Hepatic venule endothelial and Kupffer cell VT1 staining was considerably reduced by in vivo CsA treatment. We conclude that MDR1 inhibition warrants consideration as a novel adjunct treatment for neutral GSL storage diseases. [source] Ultrastructure, development and histochemistry of the polysaccharide-containing subcuticular compartments in Origanum dictamnus L. peltate glandular hairsFLAVOUR AND FRAGRANCE JOURNAL, Issue 4 2010Artemios M. Bosabalidis Abstract Peltate glandular hairs of Origanum dictamnus at the stage of secretion create two subcuticular chambers; one large and bladder-like, at the apex of the head (containing essential oil), and one small and ring-like, at the bottom of the head (containing polysaccharides). In the apical chamber, along with the essential oil, a small lateral compartment containing polysaccharides, also exists. This compartment surrounds peripherally the apical chamber creating a second ring-like structure. The apical plasmalemma of the head cells exhibits a high electron density and presumably has a specific substructure to facilitate passing to the subcuticular chamber of the secretory product. The latter probably exists in the form of glucosides, which, after passing across the plasmalemma and entering the apical chamber, become hydrolysed into the aglycone fraction (essential oil) and the sugar fraction (polysaccharides). Copyright © 2010 John Wiley & Sons, Ltd. [source] Oxidative Damage of the Gastric Mucosa in Helicobacter pylori Positive Chronic Atrophic and Nonatrophic Gastritis, Before and After EradicationHELICOBACTER, Issue 5 2003Federico Iacopini ABSTRACT Background.,Helicobacter pylori is the main cause of gastritis and a primary carcinogen. The aim of this study was to assess oxidative damage in mucosal compartments of gastric mucosa in H. pylori positive and negative atrophic and nonatrophic gastritis. Materials and methods., Five groups of 10 patients each were identified according to H. pylori positive or negative chronic atrophic (Hp-CAG and CAG, respectively) and nonatrophic gastritis (Hp-CG and CG, respectively), and H. pylori negative normal mucosa (controls). Oxidative damage was evaluated by nitrotyrosine immunohistochemistry in the whole mucosa and in each compartment at baseline and at 2 and 12 months after eradication. Types of intestinal metaplasia were classified by histochemistry. Results., Total nitrotyrosine levels appeared significantly higher in H. pylori positive than in negative patients, and in Hp-CAG than in Hp-CG (p < .001); no differences were found between H. pylori negative gastritis and normal mucosa. Nitrotyrosine were found in foveolae and intestinal metaplasia only in Hp-CAG. At 12 months after H. pylori eradication, total nitrotyrosine levels showed a trend toward a decrease in Hp-CG and decreased significantly in Hp-CAG (p = .002), disappearing from the foveolae (p = .002), but remaining unchanged in intestinal metaplasia. Type I and II of intestinal metaplasia were present with the same prevalence in Hp-CAG and CAG, and did not change after H. pylori eradication. Conclusions., Oxidative damage of the gastric mucosa increases from Hp-CG to Hp-CAG, involving the foveolae and intestinal metaplasia. H. pylori eradication induces a complete healing of foveolae but not of intestinal metaplasia, reducing the overall oxidative damage in the mucosa. [source] Enhanced Expression of Transcription Factor E2F in Helicobacter pylori -infected Gastric MucosaHELICOBACTER, Issue 3 2002Hajime Isomoto Abstract Objective.Helicobacter pylori is implicated in gastric carcinogenesis through increased gastric epithelial cell turnover. In fact, high proportions of proliferating and apoptotic epithelial cells are found in H. pylori -infected gastric mucosa. E2F, a transcription factor, induces coordinated transactivation of a set of genes involved in cell cycle progression. The aim of this study was to investigate the expression of E2F in H. pylori -infected gastric mucosa and examine the correlation between such expression and gastric epithelial cell proliferation and apoptosis. Methods. Twenty-five patients with H. pylori -associated gastritis (HAG) and 13 control subjects negative for H. pylori were examined. E2F expression was studied in situ by Southwestern histochemistry, a method used to localize transcription factors. Labeled double-stranded oligo-DNA with specific consensus sequence for E2F binding sites was reacted with frozen sections from antral biopsy specimens obtained at endoscopy. Gastric epithelial cell proliferation was assessed by immunostaining of proliferating cell nuclear antigen (PCNA), while apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL). The percentages of epithelial cells with nuclear staining for PCNA and E2F were expressed as a positivity index (PI). The percentage of TUNEL-positive epithelial cells was defined as apoptotic index. Results. E2F was expressed in the nuclei of gastric epithelial cells within gastric pits. E2F PI in H. pylori -infected gastric mucosa was significantly higher than that in noninfected. Expression of E2F correlated well with PCNA-positive epithelial cells. We also demonstrated colocalization of PCNA with E2F expression in the same epithelial cells. Apoptotic index was also high in H. pylori -infected mucosa, and correlated with E2F PI. Conclusion. Our results demonstrated a significant increase in the expression of E2F in H. pylori -infected mucosa, which correlated with both the percentages of PCNA- and TUNEL-positive cells. Our results suggest that enhanced E2F expression in gastric mucosa may be involved in H. pylori -related gastric carcinogenesis through accelerated cell turnover. [source] Critical role of NFATc1 in periapical lesionsINTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2010C. Zhang Zhang C, Yang L, Peng B. Critical role of NFATc1 in periapical lesions. International Endodontic Journal, 43, 109,114, 2010. Abstract Aim, To observe NFATc1 expression in experimental periapical lesions in rats. Methodology, Apical periodontitis was induced in Wistar rats by occlusal pulp exposure in mandibular first molar teeth. After exposure, 30 rats were killed on days 0, 7, 14, 21 and 28. The jaws that contained the first molar were removed and prepared for histological examination, immunohistochemistry and enzyme histochemistry. Results, From day 0 to day 28, the areas of periapical bone loss and the number of NFATc1-positive cells increased, peaking on day 28. The number of TRAP-positive cells increased substantially from day 0 to day 14 and then gradually decreased from day 14 to day 28. Conclusions, NFATc1 was detected and possibly involved in the inflammatory response and bone resorption of periapical tissues, as well as being associated with periapical lesion pathogenesis. [source] A histochemical study of the reproductive structures in the flatworm Dugesia leporii (Platyhelminthes, Tricladida)INVERTEBRATE BIOLOGY, Issue 2 2006Gavina Corso Abstract. The functional morphology and the topographic distribution of tissues in the reproductive system of specimens of Dugesia leporii, an endemic Sardinian free-living planarian, are investigated. Data are provided on the nature of epithelial and glandular secretions, spermatophores, and cocoons by histochemistry, light microscopy, and scanning electron microscopy. All secreting epithelial cells produce strongly acidic sulfated glycoproteins. Glandular cells secrete strongly acidic sulfated glycoproteins or keratohyalin-like material in the penis bulb, and prekeratin-like material in atrial glands. Secretions of the bursa copulatrix may be involved in the activation of sperm while material produced by the bursa canal and oviducts probably serves to propel spermatophores or sperm and eggs. Mucous secretion of the seminal vesicle may serve to dilute and activate sperm before copulation. The viscous secrete of the ejaculatory duct and vasa deferentia may play a protective role to maintain sperm viability. Materials produced by the penis papilla and atrium probably lubricate the epithelial surface. The bilayered wall of spermatophore made of keratohyalin-like material and strongly acidic sulfated glycoproteins is produced by two gland types of the penis bulb. The bilayered shell of cocoon made of prekeratin-like and keratohyalin-like materials is secreted by both atrial glands and vitelline cells. The cocoon stalk is made of keratohyalin-like material produced by cement glands. Shell glands, producing GAG, are not involved in cocoon formation, but they may be implicated in the dilution and activation of seminal material to favor sperm movement toward the oviducts. [source] Development of axonal pathways in the human fetal fronto-limbic brain: histochemical characterization and diffusion tensor imagingJOURNAL OF ANATOMY, Issue 4 2010Lana Vasung Abstract The development of cortical axonal pathways in the human brain begins during the transition between the embryonic and fetal period, happens in a series of sequential events, and leads to the establishment of major long trajectories by the neonatal period. We have correlated histochemical markers (acetylcholinesterase (AChE) histochemistry, antibody against synaptic protein SNAP-25 (SNAP-25-immunoreactivity) and neurofilament 200) with the diffusion tensor imaging (DTI) database in order to make a reconstruction of the origin, growth pattern and termination of the pathways in the period between 8 and 34 postconceptual weeks (PCW). Histological sections revealed that the initial outgrowth and formation of joined trajectories of subcortico-frontal pathways (external capsule, cerebral stalk,internal capsule) and limbic bundles (fornix, stria terminalis, amygdaloid radiation) occur by 10 PCW. As early as 11 PCW, major afferent fibers invade the corticostriatal junction. At 13,14 PCW, axonal pathways from the thalamus and basal forebrain approach the deep moiety of the cortical plate, causing the first lamination. The period between 15 and 18 PCW is dominated by elaboration of the periventricular crossroads, sagittal strata and spread of fibers in the subplate and marginal zone. Tracing of fibers in the subplate with DTI is unsuccessful due to the isotropy of this zone. Penetration of the cortical plate occurs after 24,26 PCW. In conclusion, frontal axonal pathways form the periventricular crossroads, sagittal strata and ,waiting' compartments during the path-finding and penetration of the cortical plate. Histochemistry is advantageous in the demonstration of a growth pattern, whereas DTI is unique for demonstrating axonal trajectories. The complexity of fibers is the biological substrate of selective vulnerability of the fetal white matter. [source] Contribution of Nitric Oxide Synthase to Improved Early Graft Patency in Human Saphenous Vein Graft Harvested by a Novel ,No-Touch' TechniqueJOURNAL OF CARDIAC SURGERY, Issue 6 2002JCS Tsui Aim: Saphenous vein (SV) is the most commonly used conduit in bypass procedures but has a one-year occlusion rate of 15-30%. A new ,no-touch' technique where the SV is harvested with a cushion of surrounding tissue with no distension has led to improved early patency rates of 5% at 18-months. Nitric oxide (NO), synthesised by nitric oxide synthase (NOS) has properties beneficial to graft patency. Our aim was to study the distribution of NOS in SV harvested by this technique and the effect of distension and removal of perivascular tissue on NOS content of SV. Methods: Following ethical committee approval and patients' informed consent, SVs were harvested from ten patients undergoing coronary artery bypass grafting. A segment of vein was harvested by the conventional technique (surrounding tissue stripped and vein distended with saline); another part was stripped but not distended (,control') and the remaining parts harvested by the ,no-touch' technique. Samples of each segment were taken and transverse sections prepared for NOS identification using 3[H]L-NG nitroarginine (NO Arg) autoradiography and NADPH-diaphorase histochemistry. NOS isoforms were studied using standard immunohistochemistry. Endothelial cells and nerves were also identified using immunohistochemistry with CD31 and NF200 respecitvely, to confirm sources of NOS. Morphometric analysis of NADPH-diaphorase staining was carried out to study tissue NOS content. Results: NO Arg binding representing NOS was preserved on the lumen of ,no-touch' vessels whilst that on conventional and control vessels was reduced. NOS was also localised to the medial smooth muscle cells of all vein segments and to the intact adventitia of ,no-touch' segments. This was confirmed by NADPH-diaphorase staining, which revealed a mean reduction of NOS by 19.5% (p < 0.05, ANOVA) in control segments due to stripping of surrounding tissue alone and a reduction of 35.5% (p < 0.01, AVNOVA) in conventional segments due to stripping and distension, compared to ,no-touch' segments. Adventitial NOS sources in ,no-touch' vessels corresponded to vasa vasorum and paravascular nerves. All three NOS isoforms contributed to the preserved NOS in ,no-touch' vessels. Conclusions: Apart from preserved lumenal NOS, NOS sources are also located in the media and adventitia of SV grafts. These are reduced by both adventitial damage and vein distension during conventional vein harvesting. The ,no-touch' technique avoids these procedures, preserving NOS sources. This may result in improved NO availability in SV harvested by this technique, contributing to the improved patency rates reported. [source] Sulphur, thiols, and disulphides in the fish epidermis, with remarks on keratinizationJOURNAL OF FISH BIOLOGY, Issue 4 2007W. Meyer Energy dispersive x-ray (EDX) analysis and qualitative and quantitative histochemistry were applied to study the distribution and contents of sulphur, thiols and disulphides in the epidermis of the river lamprey Lampetra fluviatilis, the lesser spotted dogfish Scyliorhinus canicula and the brown trout Salmo trutta fario. Thiols generally reacted weakly throughout the entire epidermis, whereas disulphide reactions were more distinct and differentiated. In the river lamprey, the concentrations of -S-S- groups clearly increased in the developing mucous cells from the stratum basale to the stratum superficiale; skein cells and granular cells reacted negatively to weakly. In the lesser spotted dogfish, amounts of disulphides appeared at moderate concentrations, and only goblet cells displayed a strong reaction. In the brown trout, filament cells showed low concentrations or weak reactions of disulphides, goblet cells and the most outer superficial cells stained strongly. Sulphur distribution and contents generally supported the histochemical observations in normal epidermis cells (absolute sulphur contents: 41,59 mM), only the brown trout showed high amounts of sulphur in the stratum basale (81 mM). The findings corroborate the view that there is an inverse correlation between keratinization and mucous secretion in normal fish epidermis. The sometimes distinct contents of disulphides in the outer mucous layer indicate that this system could endure higher mechanical stress than predictable from its large amounts of neutral glycoproteins. [source] Skin-type antifreeze protein expression in integumental cells of larval winter flounderJOURNAL OF FISH BIOLOGY, Issue 6 2002H. M. Murray Wholemount in situ hybridization using an antisense riboprobe complementary to a winter flounder Pleuronectes americanus skin-type antifreeze protein mRNA (WFp9) and immuno histochemistry using polyclonal antibodies to the corresponding protein detected cells expressing this gene in larval winter flounder integument. Immunohistochemistry revealed two distinct populations of cells. One population extended laterally along the length of the fish and was detectable using in situ hybridization. Staining in these cells declined following yolk-sac absorption suggesting that expression was only important here during early larval development. The polyclonal antibody for skin-type antifreeze protein also reacted with another population of cells scattered throughout the integument. These cells stained with alcian blue suggesting that they were integumental mucous cells. In situ hybridization using the above probe was not able to detect the corresponding transcript within the same cells. This suggests that another gene may be involved in the production of a similar protein in this case. These data suggest that two distinct populations of cells within the larval integument are involved in skin-type antifreeze protein expression and possibly involve the activity of at least two different genes. [source] Accumulation and Dynamic Trends of Triterpenoid Saponin in Vegetative Organs of Achyranthus bidentataJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 2 2009Jinting Li Abstract The relationship between structural features of various vegetative organs and triterpenoid saponin accumulation in Achyranthus bidentata Blume was investigated using anatomy, histochemistry and phytochemistry. The results showed that the primary and secondary structures of roots, and the structures of stems and leaves of A. bidentata, were similar to those of ordinary dicotyledonous plants. The enlargement of its roots, however, was primarily associated with growth and differentiation of tertiary structures. There were collateral medullary vascular bundles in addition to the normal vascular bundles in the stem. The tertiary structure was not only main parts in the roots of A. bidentata, but also important storage region of triterpenoid saponin in its growth and development. The stem may be the essential transport organ of triterpenoid saponin, while palisade parenchyma may be the primary synthesis location. In November, the total quantity of triterpenoid saponin and overall biomass in the roots reach a maximum level. This was the best time, therefore, to harvest the roots and corresponded to the traditional harvest period. Despite the withered appearance of leaves, stems also contained substantial amounts of triterpenoid saponin, and it was recommended that the stems of A. bidentata should be used. [source] | ||||||||||||||||||||||||||||||||||||||||