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PubMed1996

Change of calretinin expression in the human colon adenocarcinoma cell line HT29 after differentiation.

Calretinin is a Ca(2+)-binding protein of the EF-hand family which is expressed in colon adenocarcinomas and colon-derived tumor cell lines (e.g. WiDr), but is absent from normal human enterocytes. Its function has not as yet been elucidated, but some lines of evidence lead us to postulate its involvement in cell proliferation in these cells. In order to test whether calretinin is correlated with an undifferentiated, proliferating, or with a differentiated, state of cells, its expression was studied in the human colon adenocarcinoma clonal cell line HT29-18, which can be caused to differentiate into enterocyte-like cells by replacing glucose with galactose in the culture medium (glucose starvation differentiation). Treatment of HT29-18 cells with galactose led to a drop in the calretinin mRNA level and in protein expression as evidenced by immunocytochemical staining and Western blot analysis of cytosolic cell extracts. These results suggest that calretinin is present in HT29-18 cancer cells, mostly in those which are in the undifferentiated state. The possibility that calretinin is involved in maintaining the cells in an undifferentiated (cancerous) state is discussed.

Aminopeptidases↗
PubMed2003

Differential impact of hypergravity on maturating innervation in vestibular epithelia during rat development.

Over the past decades, the new opportunity of space flights has revealed the importance of gravity as a mechanical constraint for terrestrial organisms as well as its influence on the somatosensory system. The lack of gravitational reference in orbital flight induces changes in equilibrium, with major modifications involving neuromorphological and physiological adaptations. However, few data have illustrated the putative effect of gravity on sensory vestibular epithelial development. We asked if gravity, the primary stimulus of utricles could act as an epigenetic factor. As sensorial deprivation linked to weightlessness is technically difficult, we used a ground-based centrifuge to increase the gravitational vector, in order to hyperstimulate the vestibule. In this study, 3 days after mating, pregnant females were submitted to hypergravity, 2 g (HG). Their embryos were raised, born and postnatally developed under HG. The establishment of connections between primary vestibular afferent neurons and hair cells in the utricle of these young rats was followed from birth to postnatal day 6 (PN6) and compared to embryos developed in normogravity (NG): Immunocytochemistry for neurofilaments and microvesicles revealed the differential effects of gravity on the late neuritogenic and synaptogenic processes in utricles. Taking type I hair cell innervation as a criterion of maturation, we found that primary afferent fibres reached the vestibular epithelium and enveloped hair cells in the same way, both under NG and HG. Thus, this phenomenon of leading growth cones to their epithelial target appears to be dependent on intrinsic genetic properties and not on an external stimulus. In contrast, the maturation of connection processes between type 1 hair cells and the afferent calyx, concerning specifically the microvesicles at their apex, was delayed under HG. Therefore, gravity appears to be an epigenetic factor influencing the late maturation of utricles. These differential effects of altered gravity on the development of the vestibular epithelium are discussed.

Animals↗
PubMed2005

Intracerebral schwannoma clinically and radiologically mimicking meningioma.

A case of intracerebral schwannoma (ICS) occurring in a 33-year-old woman is presented. The patient's history of headache, numbness, tingling and the recent development of weakness of the right upper extremity with right facial droop began during pregnancy. Magnetic resonance imaging (MRI) showed a 4 x 2 x 2 cm heterogeneous, gadolinium-enhanced mass at the left frontoparietal junction, with peritumoral edema and a dural-based attachment. During her pregnancy, the mass increased in size. The surgically resected specimen consisted of lobulated, somewhat gelatinous soft tissue. Microscopically, the tumor demonstrated classic biphasic Antoni type A and B patterns, admixed with degenerative changes. Immunohistochemically, the neoplastic cells were positive for S-100 protein (diffuse and strong), CD34 (primarily in Antoni B areas), glial fibrillary acidic protein (GFAP; weak and diffuse) and calretinin (mainly in Antoni A areas), while none was positive for CD31, estrogen and progesterone receptors, bcl-2, or epithelial membrane antigen (EMA). Ultrastructurally, basal laminae and Luse bodies were identified. The differential diagnosis includes fibrous meningioma, solitary fibrous tumor, and ICS. Twenty-seven cases of ICS were reviewed in which the histological diagnosis was confirmed immunohistochemically or ultrastructually, and the cases were summarized (including the present case). A combined use of immunostains (S-100 protein, EMA, CD34, and maybe calretinin) is of great help in distinguishing ICS from its histological mimickers.

Adult↗
PubMed1996

The calcium-binding protein calretinin-22k, an alternative splicing product of the calretinin gene is expressed in several colon adeno carcinoma cell lines.

An alternatively spliced mRNA for the calcium-binding protein calretinin (CR) is present in the colon adenocarcinoma cell line WiDr. As a consequence of a frame shift, the resulting protein, calretinin-22k (CR-22k), consists of the first 178 amino acids of calretinin followed by a carboxy-terminal peptide of 14 amino acids that is not present in full-length calretinin. Antibodies specific for this C-terminal region have been generated by 2 different methods. A peptide corresponding to the specific C-terminal region of CR-22k was either chemically synthesized and coupled to a carrier protein or was expressed in Escherichia coli as a carboxyterminal fusion to a carrier protein applying recombinant techniques. Both antisera produced in rabbits were tested in Western blots and immuno-histochemical experiments. The antisera recognized human recombinant CR-22k overexpressed in E. coli, but not fulllength calretinin and stained fixed WiDr cells. The presence of CR-22k was also confirmed in the colon cell lines CO115/3 in which mRNA coding for CR-22k mRNA coding for CR-22k mRNA is present as well as in the lines COLO205 and LS-180, all of which also express full-length calretinin. Although the intracellular distribution of CR-22k and CR are similar as evidenced by immunohistochemical stainings, CR-22k is preferentially localized in the nucleus in the cell lines LS-180 and Co115/3 suggesting potentially different roles for the two proteins.

Adenocarcinoma↗
PubMed2003

Upregulation of calretinin immunostaining in the ferret inferior colliculus after cochlear ablation.

In many systems, including ascending auditory pathways, calcium-binding proteins are markers of specific neuronal circuits. Previous studies suggest that calretinin immunostaining may be a specific marker for circuits in the inferior colliculus (IC) that code timing information. We undertook experiments to determine the changes in calretinin immunostaining in the IC that take place in response to cochlear ablation. Cochlear ablation was performed unilaterally in ferrets just after hearing onset. Animals survived for 2-3 months after ablation and brains were then processed for calretinin immunocytochemistry. The mean optical density and stained area of the calretinin immunopositive plexus in the IC were determined for five coronal sections through the right and left IC. In controls (n = 3), measurements of these parameters in the central nucleus of the IC showed symmetry between the two sides. In experimental animals (n = 8) the calretinin immunopositive plexus contralateral to the cochlear ablation was denser and larger than that in either the ipsilateral IC or in the IC of control animals. The calretinin plexus in the ipsilateral IC was slightly less dense and smaller than in controls but the differences did not reach statistical significance. IC volume measurements and synaptophysin immunostaining analysis in the central nucleus of the IC revealed no statistical differences between ablated and control animals or between the two sides in ablated animals. The significant increase in both mean optical density and immunostained area of the calretinin plexus in the IC contralateral to the cochlear ablation may reflect an upregulation in calretinin expression in the nuclei that contribute to this plexus.

Animals↗
PubMed2003

Grafting of a new target prevents synapse loss in abducens internuclear neurons induced by axotomy.

The loss of afferent synaptic boutons is a prominent alteration induced by axotomy on adult central neurons. In this work we attempted to prove whether synapse loss could be reverted by reconnection with a new target. We severed the medial longitudinal fascicle of adult cats and then transplanted embryonic cerebellar primordia at the lesion site immediately after lesion. As previously shown, the transected axons from abducens internuclear neurons penetrate and reinnervate the graft [J Comp Neurol 444 (2002) 324]. By immunocytochemistry and electron microscopy we studied the synaptology of abducens internuclear neurons under three conditions: control, axotomy and transplant (2 months of survival time). Semithin sections of the abducens nucleus were immunostained against calretinin, to identify abducens internuclear neurons, and either synaptophysin (SF), to label synaptic terminals, or glial fibrillary acidic protein (GFAP) to detect the astrocytic reaction. Optical and linear density of SF and GFAP immunostaining were measured. Data revealed a significant decrease in the density of SF-labeled terminals with a parallel increase in GFAP-immunoreactive elements after axotomy. On the contrary, in the transplant group, the density of SF-labeled terminals was found similar to control, and the astrocytic reaction induced by lesion was significantly reduced. At the ultrastructural level, synaptic coverage and linear density of boutons were measured around the somata of abducens internuclear neurons. Whereas a significant reduction in both parameters was found after axotomy, cells of the transplant group received a normal density of synaptic endings. The ratio between F- and S-type boutons was found similar in the three groups. Therefore, these findings indicate that the grafting of a new target can prevent the loss of afferent synaptic boutons produced by the axotomy.

Abducens Nerve↗
PubMed2004

Alterations in calretinin immunostaining in the ferret superior olivary complex after cochlear ablation.

In this study, we used image analysis to assess changes in calretinin immunoreactivity in the lateral (LSO) and medial (MSO) superior olivary nuclei in ferrets 2 months after unilateral cochlear ablations at 30-40 days of age, soon after hearing onset. These two nuclei are the first significant sites of binaural convergence in the ascending auditory system, and both receive direct projections from the deafferented cochlear nucleus. Cochlear ablation results in a decrease in the overall level of calretinin immunostaining within the LSO ipsilaterally compared with the contralateral side and with control animals and within the MSO bilaterally compared with control ferrets. In addition, the level of calretinin immunostaining ipsilaterally within neurons in the LSO was significantly less in cochlear ablated than control animals. In contrast, there was no effect of cochlear ablation on the level of calretinin immunostaining within neurons either in the contralateral LSO or in the MSO. These results are consistent with a downregulation in calretinin within the neuropil of MSO bilaterally and LSO ipsilaterally, as well as a downregulation in calretinin within somata in the ipsilateral LSO as a result of unilateral cochlear ablation soon after hearing onset. Thus, cochlear-driven activity appears to affect calcium binding protein levels in both neuropil and neurons within the superior olivary complex.

Animals↗
PubMed2003

Saccadic omnipause and burst neurons in monkey and human are ensheathed by perineuronal nets but differ in their expression of calcium-binding proteins.

The extracellular matrix of the brain contains large aggregates of chondroitin sulfate proteoglycans (CSPG), which form lattice-like cell coatings around distinct neuron populations and are termed perineuronal nets. The function of perineuronal nets is not fully understood, but they are often found around neurons containing the calcium-binding protein parvalbumin, suggesting a function in primarily highly active neurons. In the present paper the distribution of perineuronal nets was studied in two functional cell groups of the primate oculomotor system with well-known firing properties: 1) the saccadic omnipause neurons in the nucleus raphe interpositus (RIP) exhibit a high tonic firing rate, which is only interrupted during saccades; they are inhibitory and use glycine as a transmitter; and 2) premotor burst neurons for vertical saccades in the rostral interstitial nucleus of the medial longitudinal fascicle (RiMLF) fire with high-frequency bursts during saccades; they are excitatory and use glutamate and/or aspartate as a transmitter. In the macaque monkey, both cell populations were identified by their parvalbumin immunoreactivity and were studied for the presence of perineuronal nets using CSPG antibodies or lectin binding with Wisteria floribunda agglutinin. In addition, the expression of another calcium-binding protein, calretinin, was studied in both cell groups. Double- and triple-immunofluorescence methods revealed that both omnipause and burst neurons are selectively ensheathed with strongly labeled perineuronal nets. Calretinin was coexpressed in at least 70% of the saccadic burst neurons, but not in the omnipause neurons. Parallel staining of human tissue revealed strongly labeled perineuronal nets around the saccadic omnipause and burst neurons, in corresponding brainstem regions, which specifically highlighted these neurons within the poorly structured reticular formation. These findings support the hypothesis that perineuronal nets may provide a specialized microenvironment for highly active neurons to maintain their fast-spiking activity and are not related to the transmitter or the postsynaptic action of the ensheathed neurons.

Animals↗
PubMed1998

[Calretinin immunoreactivity in olfactory bulb and mucosa in mice].

The vertebrate olfactory system is capable of recognizing and discriminating thousands of different odorant molecules. In vitro biochemical studies have shown that some odorants elicit an increase in the intercellular second messenger cyclic AMP, whereas other odorants cause an increase in the second messenger inositol triphosphate (IP3). If IP3 plays an important role in the signal transduction, calcium-binding protein will be needed. We investigated the expression of calretinin, which belongs to the E-F hand family, in the neonatal and adult olfactory mucosa and olfactory bulb. Mice were sacrificed on postnatal day 1 (P1), day 3 (P3), day 10 (P10) and 12 weeks as adults. The olfactory mucosa of the nasal septum and the olfactory bulb were stained with anti-calretinin antibody at a 1:1000 dilution for 48 hours. The results were as follows. 1) Olfactory mucosa: In the P1 mouse, the olfactory nerves running in the submucosal layer and olfactory cells in the epithelium were positive. In the epithelium, immunopositive spots were seen exclusively in the upper half of the epithelium. In the P3, P10 and adult mice, these spots were seen throughout the olfactory cell layer. However, the basal cell layer and supporting cells were negative. 2) Olfactory bulb: In all stages, the olfactory nerve layer and the glomerular layer were strongly stained. In the external plexiform layer, many cells were positive. Their shape was bipolar and the size of the cell body was thought to be about 20 microns. They were thought to be tufted cells. However, there is a possibility that these cells are short axon cells in the external plexiform layer. In the granule layer, some granule cells were positive. In the P1 mouse, the immunopositive spots were exclusively seen in the upper half of the epithelium. In contrast, in the P3 mouse, these spots were seen throughout the olfactory cell layer. Judging from our results, it is suspected that the important change in neurogenesis of olfactory cells occurred between P1 and P3. In the olfactory bulb, from P1 to adult mice, calretinin was positive in the olfactory nerve layer, the glomerulus and periglomerular cells. In contrast, mitral cells were negative. Most reports state that calcium binding protein appears in periglomerular cells. However, in the external plexiform layer, many cells were positive. As their shape was bipolar and the cell body was a little larger than the periglomerular cells, these cells were thought to be tufted cells.

Animals↗
PubMed2005

Granular cell tumor of the penis: clinicopathologic evaluation of 9 cases.

The occurrence of granular cell tumor (GCT) in penile tissue is very rare, with only 9 examples reported to date in the English-language literature. Herein, we describe the clinicopathologic and immunohistochemical findings in 9 additional cases. The patients ranged in age from 20 to 60 years (mean, 42 years; median, 40 years) at time of diagnosis. All penile tumors were solitary and arose in the dermis of the penile shaft (n=4), prepuce (n=3), and corona (n=2). A patient had a history of multiple cutaneous GCTs. Duration of symptoms before surgery ranged from 5 days to 2 years with the presence of an asymptomatic nodule representing the most common tumor-related complaint (n=8). The lesions ranged in size from 0.6 to 2.5 cm (mean, 1.5 cm; median, 1.5 cm). Microscopically, the tumors were moderate to highly cellular and were composed of oval to polygonal-shaped cells with abundant coarsely granular eosinophilic cytoplasm. Tumor cells grew in infiltrating nests, cords, and trabeculae and showed neural (n=2) and vessel wall (n=1) invasion or formed a relatively well-marginated solid nodule. Bland cytological features with only rare cells showing nucleomegaly (n=7) or spindling (n=3) were exhibited by 8 tumors. A tumor demonstrated diffuse nuclear atypia and was classified as "atypical." Mitotic activity ranged from 0 to 8 mitoses (mean, 1.4 mitoses) per 50 high-powered fields with no atypical division figures identified. All tumors tested showed moderate to strong immunohistochemical expression of S100 protein (n=6) and low-affinity nerve growth factor receptor (n=5), which was useful for detecting small deposits of tumor and helpful in evaluating surgical margins. Focal tumor cell immunoreactivity was observed for calretinin (4/6 cases) and glial fibrillary acidic protein (1/6 cases). All patients underwent simple (local) excision of their tumor. Complete follow-up data (mean, 21 years; interval range, 0.5-28 years) were available for 6 patients. No patient experienced recurrence or metastatic spread of tumor although surgical margins were microscopically involved by tumor in 5 cases. Benign GCT involving superficial soft tissue of the penis can be adequately managed by a simple excision. Patients with microscopically involved surgical margins can be clinically followed without immediate additional surgery.

Adult↗
PubMed1995

Calretinin immunoreactivity in adrenal glands of developing, adult and ageing Sprague-Dawley rats.

Localization of calretinin immunoreactivity in the rat adrenal gland was studied using immunohistochemical methods. Calretinin-immunoreactive adrenal chromaffin cells and nerve fibres were found at all of the ages examined from embryonic day 16 up to 2-yr-old. Immunoreactive chromaffin cells showed a decrease in number with increasing age, and in the adult and ageing rats they were found among the adrenaline-storing chromaffin cells. Calretinin immunofluorescence was also observed in a few ganglion cells of the adult and ageing rats, and in most of the cortical cells at embryonic day 16. The density of immunoreactive nerve fibres in the gland showed a progressive increase with age to a peak by day 4 after birth and then a gradual decrease afterwards; they became associated mainly with some of the ganglion cells in the adult rat. As revealed by double labelling of calretinin immunoreactivity in adrenal sections from the adult rat with NADPH-diaphorase histochemistry, no co-localization existed between calretinin and NADPH-diaphorase; however, a small number of neuronal cell bodies which contained nitric oxide synthase were found heavily surrounded with calretinin-immunoreactive nerve fibres. In ageing rats, an increased density of calretinin-immunoreactive nerve fibres was seen associated largely with the chromaffin cells. We conclude from this study that calretinin is found in the rat adrenal gland; the high degree of variability in its expression with age suggests that calretinin may be concerned with age-related activities in the gland.

Adrenal Glands↗
PubMed1996

Involvement of adenosine in retinal ischemia. Studies on the rat.

PURPOSE: The aim of this study was to determine whether adenosinergic agents can be used to slow down the changes seen in the rat retina after ischemia-reperfusion. METHODS: Ischemia-reperfusion injury to the rat retina was induced by raising the intraocular pressure above the systolic blood pressure for 45 minutes, followed by reperfusion for 3 days. This insult caused a reduction of the b-wave of the electroretinogram (54% +/- 5%, n = 23) relative to the contralateral control retina, an expression of glial fibrillary acidic protein (GFAP) in the Müller cells, and an alteration in the "staining" pattern of the calretinin immunoreactivity. The normal two to three bands of calretinin immunoreactivity in the inner plexiform layer appeared as a single band. Elevation of the intraocular pressure for 60 minutes, followed by reperfusion of 2 weeks, caused a 40% reduction in the thickness of the inner nuclear and plexiform layers. No statistically significant changes in the other retinal layers were recorded. RESULTS: When the adenosine deaminase inhibitor erythro-9-(2-hydroxyl-3-nonyl)adenine (EHNA) was injected into the eye just before ischemia, the ischemia-reperfusion changes in the b-wave and calretinin immunoreactivity were largely prevented. Similar results were observed when the adenosine A1 receptor agonist, R-N6-(2-phenylisopropyl)adenosine (R-PLA), was administered intraperitoneally just before ischemia. Injection of adenosine deaminase into the eye before ischemia seemed to potentiate the ischemia-reperfusion effect because the reduction of the b-wave was almost complete (8% +/- 4%, n = 6). The ischemia-reperfusion-induced expression of GFAP in the Müller cells was not reduced by any of the adenosinergic agents tested. This suggests that GFAP expression in the Müller cells is not related to a reduction in the b-wave. An injection of EHNA into the eye before ischemia reduced the thinning of the inner plexiform and nuclear retinal layers so that no significant difference between them and the control retinas existed. However, an injection of R-PIA just before ischemia did not reduce the thinning of the retinal layers in a statistically significant way, possibly because the R-PIA protective effect is less than that of EHNA and is difficult to detect when thickness of the retinal layers is measured. It may be necessary to use higher concentrations of R-PIA to observe a protective effect. CONCLUSIONS: The combined data show that substances resulting in the activation of adenosine A1 receptors protect the retina against changes induced by ischemia-reperfusion.

Adenine↗
PubMed1999

Diversity of the calretinin immunoreactivity in the dentate gyrus of gerbils, hamsters, guinea pigs, and laboratory shrews.

We have recently reported that calretinin (CR) immunoreactivity in the mouse dentate gyrus (DG) is prominently different from that in the rat and monkey dentate gyrus. The CR-immunoreactive (IR) neuronal components characteristic of mouse DG were (1) mossy cells in the ventral hilus, (2) punctate elements in the inner molecular layer, (3) Cajal-Retzius cells in the molecular layer, and (4) immature granule cells at the basal part of the granule cell layer, which were also IR for highly polysialylated neural cell adhesion molecule. In this study, we examine the CR-IR elements in the DG of the gerbil, hamster, guinea pig, and laboratory shrew, and compare them with those of the rat, monkey, and mouse, reported previously. We show that mossy cells are distributed throughout the dorsoventral axis in all these animals, but mossy cells in the ventral hilus of the hamster, gerbil, and laboratory shrew are CR-IR, resembling those of the mouse, whereas mossy cells of the guinea pig are CR negative, like those of the rat. The inner molecular layer, the target zone of mossy cells, was observed to contain CR-IR punctae in the hamster, gerbil, and laboratory shrew, which corresponds to the CR immunoreactivity of the mossy cells. In addition, we observed CR-IR presumed Cajal-Retzius cells in all animals examined. On the other hand, CR-IR immature granule cells were encountered in the laboratory shrew, but not in other animals. The present study reveals prominent species differences in the CR-IR elements of the DG.

Animals↗
PubMed1999

Characterization of nodular neuronal heterotopia in children.

Neuronal heterotopia are seen in various pathologies and are associated with intractable epilepsy. We examined brain tissue from four children with subcortical or periventricular nodular heterotopia of different aetiologies: one with severe epilepsy following focal brain trauma at 17 weeks gestation, one with hemimegalencephaly and intractable epilepsy, one with focal cortical dysplasia and intractable epilepsy, and one dysmorphic term infant with associated hydrocephalus and polymicrogyria. The connectivity of nodules was investigated using histological and carbocyanine dye (DiI) tracing techniques. DiI crystal placement adjacent to heterotopic nodules revealed numerous DiI-labelled fibres within a 2-3 mm radius of the crystals. Although we observed labelled fibres closely surrounding nodules, the majority did not penetrate them. Placement of DiI crystals within nodules also identified a limited number of projections out of the nodules and in one case there was evidence for connectivity between adjacent nodules. The cellular and neurochemical composition of nodules was also examined using immunohistochemistry for calretinin and neuropeptide Y (NPY), which are normally expressed in GABAergic cortical interneurons. Within heterotopic nodules from all cases, numerous calretinin-positive neurons were identified, along with a few cell bodies and many processes positive for NPY. Calretinin-positive neurons within nodules were less morphologically complex than those in the cortex, which may reflect incomplete differentiation into an inhibitory neuronal phenotype. There were also abnormal clusters of calretinin-positive cells in the overlying cortical plate, indicating that the migratory defect which produces heterotopic nodules also affects development of the cortex itself. Thus, heterotopic nodules consisting of multiple neuronal cell types are associated with malformation in the overlying cortical plate, and have limited connectivity with other brain regions. This abnormal development of connectivity may affect neuronal maturation and consequently the balance of excitation and inhibition in neuronal circuits, leading to their epileptogenic potential.

Brain Chemistry↗
PubMed2001

[Clinical pathological analysis of adenomatoid tumor in uterus and ovaries].

OBJECTIVE: To study the immunohistochemical feature and the differential diagnosis of adenomatoid tumors in uterus and ovaries. METHODS: Clinical pathological analysis and immunohistochemical studies were performed on 24 cases of adenomatoid tumors in the uterus and ovaries. RESULTS: Of the 24 cases, 21 cases were in the uterus, 2 cases in the ovaries and 1 cases in both the uterus and the ovary. Grossly, the mean diameter of the 22 uterus tumors was 2.2 cm, ranging from 0.2 - 5.5 cm. 14 (63.6%) were located in the subserosa or near by the subserosa of the uterine cornua. The other 8 tumors located in the myometrium. The cut surface presented a nodular pattern with grayish white or yellowish in color, partially cystic. 3 ovarian tumors became all cystic, without a clear-cut margin from the surroundings. Microscopically, the tumor consisted of various gland-like structure or luminal spaces lined with flat, cuboidal or low columnar cells, similar to blood vessels in structure. Among the tumor cells, there were scattered vesicular cells with large or small vacuoles, but no nuclear atypia and mitotic figures detected. Immunohistochemical staining showed the tumor cells positive for vimentin, AE(1)/AE(3) and calretinin, but negative for F VIII-Rag. S-100 and EMA were positive in 20 (83.3%) and 4 (16.7%) cases respectively. CONCLUSION: Adenomatoid tumor of the female genital tract is mesothelial in origin and uterus was considered as the most common site of occurance. Immunohistochemical phenotypes can be used as an important evidence for differential diagnosis. The biological behavior of adenomatoid tumor is benign and with a good prognosis.

Adenomatoid Tumor↗
PubMed1995

Calretinin-immunoreactivity in mitral cells of the rat olfactory bulb.

We addressed the question whether the projection neurons of the olfactory bulb, i.e. the mitral and tufted cells, are immunoreactive for the calcium-binding protein, calretinin. The following approaches were adopted: (1) light and electron microscopic calretinin-immunocytochemistry; (2) neuroanatomical tracing combined with calretinin-immunocytochemistry according to double-peroxidase and double-fluorescence protocols; (3) unilateral lesion of the olfactory bulb combined with calretinin-immunocytochemistry. The experiments were carried out in rats. Immunostaining of brain sections revealed weakly calretinin-immunopositive mitral cell bodies. Tufted cells were immunonegative. In contrast, fibers in the lateral olfactory tract were strongly immunopositive. Dense immunostaining was also present in a superficial band in layer I of the olfactory tubercle, piriform cortex, periamygdaloid cortex, and in the lateral entorhinal cortex. In electron microscopic preparations of these target areas we observed immunoreaction product in axons and axon terminals. The latter invariably formed asymmetrical synapses, mostly with dendritic spines. Injections of the neuroanatomical tracer biotinylated dextran amine (BDA) into the olfactory bulb produced labeled fibers which remained completely restricted to the superficial, calretinin-immunopositive band in layer I in the above-mentioned cortical forebrain areas. We noted colocalization of transported BDA and calretinin-immunoreactivity in mitral cells, in fibers in the lateral olfactory tract and in fibers in the piriform cortex. Olfactory bulb lesions produced depletion of calretinin-immunoreactivity in the lateral olfactory tract and the superficial band in the olfactory cortex-related areas. Together these data firmly indicate that mitral cells and their axons are calretinin-immunoreactive.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2005

Vesicular glutamate transporter 1 immunoreactivity in extrinsic and intrinsic innervation of the rat esophagus.

Encouraged by the recent finding of vesicular glutamate transporter 2 (VGLUT2) immunoreactivity (-ir) in intraganglionic laminar endings (IGLEs) of the rat esophagus, we investigated also the distribution and co-localization patterns of VGLUT1. Confocal imaging revealed substantial co-localization of VGLUT1-ir with selective markers of IGLEs, i.e., calretinin and VGLUT2, indicating that IGLEs contain both VGLUT1 and VGLUT2 within their synaptic vesicles. Besides IGLEs, we found VGLUT1-ir in both cholinergic and nitrergic myenteric neuronal cell bodies, in fibers of the muscularis mucosae, and in esophageal motor endplates. Skeletal neuromuscular junctions, in contrast, showed no VGLUT1-ir. We also tested for probable co-localization of VGLUT1-ir with markers of extrinsic and intrinsic esophageal innervation and glia. Within the myenteric neuropil we found, besides co-localization of VGLUT1 and substance P, no further co-localization of VGLUT1-ir with any of these markers. In the muscularis mucosae some VGLUT1-ir fibers were shown to contain neuronal nitric oxide synthase (nNOS)-ir. VGLUT1-ir in esophageal motor endplates was partly co-localized with vesicular acetylcholine transporter (VAChT)/choline acetyltransferase (ChAT)-ir, but VGLUT1-ir was also demonstrated in separately terminating fibers at motor endplates co-localized neither with ChAT/VAChT-ir nor with nNOS-ir, suggesting a hitherto unknown glutamatergic enteric co-innervation. Thus, VGLUT1-ir was found in extrinsic as well as intrinsic innervation of the rat esophagus.

Animals↗
PubMed2001

Calretinin and calretinin-22k increase resistance toward sodium butyrate-induced differentiation in CaCo-2 colon adenocarcinoma cells.

Calretinin (CR) and the alternatively spliced form calretinin-22k (CR-22k) are members of the EF-hand family of Ca(2+)-binding proteins (CaBPs). CR is expressed in more than 60% of poorly differentiated human colon tumors and both isoforms are present in several colon carcinoma cell lines (e.g., WiDr). They are absent in normal enterocytes and in well-differentiated adenocarcinoma cell lines such as CaCo-2. Calretinins are thought to act as Ca(2+) buffers and to be involved in the regulation of Ca(2+)-dependent processes. Down-regulation of calretinins in WiDr cells by antisense oligonucleotides leads to growth inhibition and treatment with sodium butyrate (NaBt, an inducer of differentiation) leads to a blockage of the cell cycle and, in parallel, to down-regulation of CR. It has been proposed that CR and/or CR-22k may be involved in maintaining the undifferentiated phenotype of WiDr cells and contributing to the transformation of enterocytes. Expression levels and distribution of CR-22k were investigated in WiDr cells. CR-22k was down-regulated in NaBt-treated cells and the normally cytoplasmic protein was preferentially localized in the nucleus either as a result of translocation or selective nuclear maintenance, a process more pronounced than in the case of CR. To compare functional differences of calretinins, CR-negative Caco-2 cells were stably transfected with cDNAs encoding CR or CR-22k. Cell growth of CR-transfected cells was increased, an effect that was not observed in CR-22k-transfected ones. The CR-expressing clones were almost completely resistant to treatment with 0.5 mM NaBt, a concentration significantly reducing cell growth in control cells. The same effect was obtained in the CR-22k-expressing clones, although to a lesser extent. This implicates that expression of CR and/or CR-22k in colon tumor cells may contribute to tumorigenesis by blocking differentiation-promoting signals.

Acetamides↗