Striatal cells containing the Ca2+-binding protein calretinin (protein 10) in ischemia-induced neuronal injury

The present study concerns the vulnerability of striatal interneurons immunopositive for the Ca²⁺-binding protein calretinin to ischemic neuronal injury. An immunohistochemical study was carried out on the striata of rats which had undergone transient middle cerebral artery occlusion. Two weeks after the ischemia, there was a marked reduction in the number of calretinin-positive neurons in the ipsilateral ischemic lesion, although the striatal interneurons positive for parvalbumin, which are a neuronal population distinct from the calretinin-immunoreactive cells in the striatum, were spared in the insulted areas. The present data indicate that the striatal calretinin-positive neurons are less resistant to transient ischemia, suggesting that there may exist vulnerability differences among the striatal interneurons in ischemia-induced neuronal injury.     

S100 protein-immunoreactive primary sensory neurons in the trigeminal and dorsal root ganglia of the rat

The cell body size (cross-sectional area) of S100-immunoreactive (-ir) primary neurons was measured in the trigeminal (TG) and lumbar dorsal root ganglia (DRG). About a half of neurons exhibited S100-immunoreactivity (-ir) in the DRG (44.0%) and TG (59.0%). DRG neurons with cell bodies >1200 μm² mostly exhibited S100-ir (96.5%), whereas S100-ir DRG neurons <600 μm² were rare (8.0%). 36.6% of DRG neurons in the cell size range 600–1200 μm² showed the ir. TG neurons >800 μm² mostly exhibited S100-ir (93.1%), whereas those <400 μm² were devoid of it (positive cells 10.5%). 58.3% of TG cells in the range 400–800 μm² contained S100-ir. Double-immunofluorescence method revealed the co-expression of S100 and other calcium-binding proteins. Parvalbumin-ir neurons mostly exhibited S100-ir in the DRG (97.4%) and TG (97.0%). The co-expression of S100 and calbindin D-28k was very rare in the DRG, because the DRG contained few calbindin D-28k-ir neurons. Unlike in the DRG, numerous neurons co-expressed S100- and calbindin D-28k-ir in the TG. Most calbindin D-28k-ir TG neurons were also immunoreactive for S100 (90.7%). Sub-populations of calretinin (CR)-ir neurons co-expressed S100-ir in both the DRG (68%) and TG (50.0%). Virtually all CR-ir neurons >1400 μm² co-expressed S100-ir in the DRG (100%) and TG (95.9%). CR-ir neurons <800 μm² were rarely exhibited S100-ir (DRG 18.0%, TG 21.9%). 71.3 and 60.5% of CR-ir neurons in the range 800–1400 μm² co-expressed S100-ir in the DRG and TG, respectively. The present study indicates that S100 is closely correlated to the primary neuronal cell size in the DRG and TG.     

Report of a Case of Pericardial Mesothelioma with Liver Metastases Responding Well to Pemetrexed and Platinum-Based Chemotherapy

Pericardial mesothelioma remains a disease with a bleak prognosis. We report the case of a patient with metastases to liver and good response to pemetrexed and carboplatin-based combination chemotherapy and consequent prolonged progression-free survival.     

Calretinin is differentially localized in magnocellular oxytocin neurons of the rat hypothalamus. A double-labeling immunofluorescence study

By use of a double-labeling immunofluorescence method with a confocal laser scanning microscope, we have examined whether a calcium-binding protein, calretinin, is localized in magnocellular oxytocin and vasopressin neurons of the rat hypothalamus. In the supraoptic nucleus, all oxytocin-labeled cells were stained for calretinin. However, in the magnocellular part of the paraventricular nucleus, almost all oxytocin-stained cells were devoid of calretinin immunoreactivity. All vasopressin-positive cells of both the supraoptic nucleus and the magnocellular part of the paraventricular nucleus lacked calretinin immunoreactivity. No calretinin immunoreactivity was found in oxytocin-labeled cells of the the anterior commissural nucleus or in vasopressin-labeled cells of the suprachiasmatic nucleus. We previously showed that another calcium-binding protein, calbindin-D28k, was localized in magnocellular oxytocin neurons of the supraoptic nucleus but not in those of the paraventricular nucleus. These findings suggest that, in general, magnocellular oxytocin neurons of the supraoptic nucleus and those of the paraventricular nucleus can be chemically distinguished, that is, the former contain both calretinin and calbindin-D28k but the latter lack the two calcium-binding proteins.     

DNA strand breaks in Alzheimer's disease

The shell and core of the nucleus accumbens exhibit different vulnerabilities to neurotoxins. Calcium binding proteins are reported to offer some neuroprotection against excitotoxicity by suppressing or buffering intracellular calcium. Differences in the distributions of the calbindin-D 28kD (CB) and calretinin (CR) might be related to the different vulnerabilities to neurotoxins of dopaminergic neurons in the ventral mesencephalon that project to the core and medial shell of the nucleus accumbens. To address this possibility, Fluoro-Gold (FG) was injected into accumbens subterritories and numbers of retrogradely labeled neurons in the ventral tegmental area containing CB and CR immunoreactivities (ir) were expressed as a percentage of total numbers of labeled neurons. The perikaryal diameters and lengths of the immunoreactive dendrites of FG labeled neurons were also measured. About 70% and 35% of retrogradely labeled cells observed following core and medial shell injections, respectively, exhibited CB immunoreactivity. Differences were not observed in the percentages of FG labeled cells exhibiting CR immunoreactivity following medial shell (13%) and core (15%) injections. The mean perikaryal diameters and median summed lengths of dendrites of retrogradely labeled neurons containing CB were smaller than in labeled neurons lacking CB following injections in both core and medial shell of the nucleus accumbens. The data indicate that the different 6-hydroxydopamine (6-OHDA) vulnerabilities of ventral mesencephalic dopaminergic neurons are not obviously related to the presence of CB and CR.     

Choline acetyltransferase is found in terminals of horizontal cells that label with GABA, nitric oxide synthase and calcium binding proteins in the turtle retina

In this study, we discriminated the various types of horizontal cell in the turtle retina on their content of neuroactive substances. Double label immunocytochemistry was performed on sectioned and wholemount retina using antisera to neural- and endothelial-nitric oxide synthase (nNOS, and eNOS), calretinin (CR), calbindin (CB), gamma-aminobutyric acid (GABA) and choline acetyltransferase (ChAT). H1 cells and their axon terminals label with CR, CB and GABA. Only H1 axon terminals label with eNOS. H2 cells contain CB, CR, nNOS and GABA maybe in their dendrites. H3 cells label only with nNOS. The localization of nNOS in the H2 and H3 cells is a novel finding. None of these antibodies labels H4 cells. The photoreceptor subtypes have been differentiated by different intensity of labeling with CB. The accessory member of the double cone is less intensely labeled with CB than the principal member and rods and blue cones do not appear to label at all. ChAT-IR is located in terminal boutons of H1 and H2 horizontal cells and H1 axon terminals and these boutons contact rods and all spectral types of cones. Clearly, GABA is present in H1 horizontal cells and may be used in neurotransmission between horizontal cells and possibly for feedback pathways to photoreceptors. The evidence of nNOS immunoreactivity in H2 and H3 horizontal cells, combined with available physiological evidence, suggests that NO may be involved in electrical coupling and/or modulation of synaptic input to these types of cells. Furthermore, our results raise the possibility that cholinergic synaptic transmission may occur from horizontal cell processes to photoreceptors in the outer plexiform layer of the turtle retina.     

Calretinin and microtubule-associated protein-2 (MAP-2) immunohistochemistry in the diagnosis of Hirschsprung's disease

Background/Purpose

Identifying ganglion cells by rectal suction biopsy is a basic diagnostic tool for the diagnosis of Hirschsprung's disease (HD). However, the difficult interpretation of conventionally processed slides often necessitates ancillary staining methods. The aim of this study was to evaluate the usefulness of calretinin and microtubule-associated protein-2 (MAP-2) immunohistochemistry in the diagnosis of HD.

Methods

We analyzed 52 rectal suction biopsy specimens (37 from 15 HD patients and 15 from 7 non-HD patients) for ganglion cells with calretinin and MAP-2 immunohistochemistry. We also analyzed full-thickness, frozen biopsy samples obtained from 15 HD patients who underwent surgery utilizing calretinin and MAP-2 immunohistochemistry.

Results

Both calretinin and MAP-2 positively stained ganglion cells in the submucosal plexus of the ganglionic bowel but not aganglionic bowel. Calretinin usually stained ganglion cell cytoplasm and nuclei more intensely than MAP-2, which only stained cytoplasm. No nerve fiber staining in the submucosal layer was observed for either antibody. In 21.1% (11/52) of samples, calretinin and MAP-2 staining found ganglion cells which were reported not to have ganglion cells in the original surgical pathology reports. Immunohistochemical staining for calretinin using paraffin-embedded tissue sections after cryostat sections clearly demonstrated decreased staining intensity compared to MAP-2.

Conclusion

Calretinin and MAP-2 are useful diagnostic markers for diagnosing HD in rectal suction biopsies. These complementary methods could ameliorate the diagnostic difficulties associated with HD.     

钙视网膜蛋白在肠无神经节细胞症诊断中的应用

目的分析钙视网膜蛋白在小儿肠无神经节细胞症诊断中的应用意义。方法回顾性分析本院自2011年1月1日至2014年12月31日收治的确诊小儿肠无神经节细胞症、肠神经节细胞发育异常症患儿术前直肠黏膜活检标本中钙视网膜蛋白的表达情况和HE染色结果、根治术或造瘘术后病变段钙视网膜蛋白表达情况和病理检查HE染色结果。结果①肠无神经节细胞症中术前直肠黏膜活检检查钙视网膜蛋白的表达在所有病例中阴性表达11 1/114例,HE染色未见神经节细胞112/114例;根治手术后痉挛段肠壁中钙视网膜蛋白均呈阴性表达133/133例,HE染色未见神经节细胞133/133例,而在扩张段的肠壁中钙视网膜蛋白的表达均呈阳性表达133/133例,HE染色可见发育正常的神经节细胞133/133例;②肠神经节细胞发育异常症中术前直肠粘膜活检钙视网膜蛋白表达阴性4/4例,HE染色见到发育不良神经节细胞1/4例,其余3例均未见到神经节细胞;根治术或造瘘术后病变段钙视网膜蛋白表达阳性42/42例,HE染色见到神经节细胞发育异常或减少42/42例。结论钙视网膜蛋白染色可以作为肠无神经节细胞症的诊断依据之一,但仍然有假阳性及假阴性结果可能,特别是在术前直肠粘膜活检的应用中。     

Characterization of calretinin-immunoreactive structures in the striatum of the rat

Previous observations have shown that the striatum contains a population of neurones that display immunoreactivity for calretinin. In order to morphologically characterize these neurones, sections of the rat striatum were immunostained to reveal calretinin and examined at both light and electron microscopic levels. The striatum contained a small population of calretinin-immunoreactive neurones, which were of medium-size (9–17 μm) and possessed few aspiny, infrequently branching dendrites which tapered to become very thin processes in their most distal portions. Although the calretinin-immunoreactive neurones were homogeneously distributed in the frontal plane, there was a marked rostrocaudal gradient with a much greater density of cells in the rostral than in the caudal parts of the striatum. At the ultrastructural level, calretinin-immunoreactive neurones were seen to possess an indented nucleus and to receive synaptic input from at least three types of boutons. In addition to the calretinin-immunoreactive neurones, the striatum also contained axons and terminal boutons that displayed immunoreactivity for calretinin. At least two types of immunoreactive terminals were identified, those forming symmetrical synaptic specialisations and those forming asymmetrical synaptic specialisations. Approximately 50% formed asymmetrical contacts with spines and 30% formed symmetrical synaptic contact with dendritic shafts. In an attempt to further chemically characterize the calretinin-containing neurones, double pre-embedding immunocytochemistry for calretinin and parvalbumin or choline acetyltransferase was carried out and calretinin immunocytochemistry was combined with histochemistry for NADPH-diaphorase. Analysis of these double-stained sections revealed that the population of calretinin-immunoreactive neurones was distinct from the populations of neurones containing parvalbumin, choline acetyltransferase or NADPH-diaphorase. It is concluded that: (1) on the basis of distribution, morphology, chemistry, ultrastructure and afferent synaptic input, the calretinin-immunoreactive neurones are distinct from the major classes of neurones that have been previously recognised in the striatum; (2) calretinin-immunoreactive terminals are heterogeneous and are probably derived from local calretinin-containing neurones and possibly other sources.