Number Of S-100 Positive Cells Research Articles

Effects of Exogenous Melatonin on Colon Glial Cells in Experimental Desynchronosis

The effect of exogenous and endogenous melatonin on GFAP and S-100 positive cells of the colon mucosa of rats kept under different lighting conditions was studied.The aim was to estimate the effect of melatonin on the structural and functional characteristics of colon glial cells in normal conditions and in experimental desynchronosis.Material and methods. The study was conducted on laboratory male Wistar rats (n=72), 2-months old, weighing 180–200 g, divided into 6 groups 12 rats in each. Group I consisted of animals treated in natural light conditions; Group II – rats treated in natural light conditions, receiving synthetic melatonin (Melaxen, Unipharm, Inc., USA) ad libitum at a concentration of 4 mg/l with drinking water; Group III – animals treated in constant darkness; Group IV – animals treated in constant darkness and received melatonin; Group V consisted of animals treated under constant lighting conditions; Group VI included rats treated in constant lighting conditions and received melatonin. Astrocytes were identified using an indirect immunohistochemical method using polyclonal antibodies to glial fibrillary acidic protein (Dako, Germany 750 µg/ml) and protein S-100 (Spring Bio Science USA 1:300). Cells were counted using a Carl Zeiss Axio Scope A1 microscope at 400 magnification and SigmaScan Pro 5 software. Statistical processing was carried out using the MS Excel and Statistica 17 programs.Results. The number of GFAP positive cells decreased in groups III and V. Conditions II and VI resulted in a decrease in the number of gliocytes. In group IV, the administration of melatonin led to an increase in the number of studied cells. A significant increase in the optical density of GFAP in colon gliocytes was observed only when rats were treated under constant lighting conditions. The number of S-100 positive cells decreased in groups III and II. Conditions V and IV led to an increase in the number of S-100 positive cells. The optical density of S-100 does not depend on photoperiod.Conclusion. S-100B and GFAP positive glial cells of the colon respond both to changes in photoperiod and to the administration of exogenous melatonin. In particular, under constant dark conditions, the number of GFAP and S-100B positive cells decreases. The obtained data can be used in the elaboration of new therapeutic approaches to the treatment of intestinal diseases.

Irinotecan-Induced Mucositis Is Associated with Goblet Cell Dysregulation and Neural Cell Damage in a Tumour Bearing DA Rat Model.

Irinotecan-induced mucositis is a major oncological problem. Goblet cells secrete mucus, protecting the intestinal mucosa, with secretion altered during mucositis. The enteric nervous system is involved in regulating gut motility and secretion. The aim of this study was to determine whether enteric neural cells and goblet cells are altered following irinotecan treatment. Tumour-bearing Dark Agouti rats were administered a single dose of 175mg/kg of irinotecan intraperitoneally and 0.01mg/kg atropine subcutaneously. Experimental and untreated control rats were killed at times 6, 24, 48, 72, 96 and 120h after treatment. Jejunum and colon samples were formalin fixed. Haematoxylin and eosin staining, Alcian Blue-PAS staining, and immunohistochemistry with S-100 antibody (neural cell marker) were carried out. Statistical analyses were carried out using Kruskal-Wallis test with Dunns post test, Mann Whitney U test and nonlinear regression. Total goblet cells decreased at 72h compared with controls in the colon (p < 0.05). The percentage of cavitated goblet cells decreased compared to all other time points at 120h in the colon. The number of S-100 positive cells in the submucosal plexus decreased in the colon (p = 0.0046) and in the myenteric plexus of the jejunum and colon (p = 0.0058 and p = 0.0022, respectively), when comparing treated with control. Enteric ganglia in the myenteric plexus of the jejunum decreased at 24h and 96h. Irinotecan-induced mucositis is associated with increases in mucus secretion, and enteric neural cell change. These changes may contribute to the pathophysiology of mucositis through the dysregulation of neural signalling.

Structural and Ultrastructural Alterations in Human Olfactory Pathways and Possible Associations with Herpesvirus 6 Infection.

Structural and ultrastructural alterations in human olfactory pathways and putative associations with human herpesvirus 6 (HHV-6) infection were studied. The olfactory bulb/tract samples from 20 subjects with an unspecified encephalopathy determined by pathomorphological examination of the brain autopsy, 17 healthy age-matched and 16 younger controls were used. HHV-6 DNA was detected in 60, 29, and 19% of cases in these groups, respectively. In the whole encephalopathy group, significantly more HHV-6 positive neurons and oligodendrocytes were found in the gray matter, whereas, significantly more HHV-6 positive astrocytes, oligodendrocytes, microglia/macrophages and endothelial cells were found in the white matter. Additionally, significantly more HHV-6 positive astrocytes and, in particular, oligodendrocytes were found in the white matter when compared to the gray matter. Furthermore, when only HHV-6 PCR+ encephalopathy cases were studied, we observed similar but stronger associations between HHV-6 positive oligodendrocytes and CD68 positive cells in the white matter. Cellular alterations were additionally evidenced by anti-S100 immunostaining, demonstrating a significantly higher number of S100 positive cells in the gray matter of the whole encephalopathy group when compared to the young controls, and in the white matter when compared to both control groups. In spite the decreased S100 expression in the PCR+ encephalopathy group when compared to PCR- cases and controls, groups demonstrated significantly higher number of S100 positive cells in the white compared to the gray matter. Ultrastructural changes confirming the damage of myelin included irregularity of membranes and ballooning of paranodal loops. This study shows that among the cellular targets of the nervous system, HHV-6 most severely affects oligodendrocytes and the myelin made by them.

Onset and dynamic expression of S100 proteins in the olfactory organ and the lateral line system in zebrafish development

In the zebrafish olfactory epithelium, three morphologically distinct olfactory neurons express different marker proteins. We utilize this feature to access developmental dynamics of one of the neuron types, the crypt cells, to determine whether they are differentiated at a stage similar to other olfactory neurons. Immunohistochemical studies using an S100 antibody that specifically recognizes crypt cells showed that S100-positive cells appear in olfactory rosettes as early as at 2day postfertilization (dpf). However, some of the rosettes did not have any S100-positive cells until 4 dpf. The number of S100-positive cells in individual rosettes increased steadily over the next 3days before it decreased significantly. There were 7.8 S100-positive cells per rosettes on average in larvae at 7 dpf. The number reduced to 2.2 at 9 dpf. A recovery to a pre-reduction level was detected in 12 dpf larvae. We also observed S100-positive cells in neuromasts of the lateral line system in 2 dpf larvae, suggesting that the crypt cells and sensory cells in the neuromasts have similar onsets of differentiation. Our data have provided a time line of differentiation of crypt cells in development of the olfactory system and demonstrated that this type of cell is differentiated at a stage similar to ciliated and microvillous olfactory neurons. A nonlinear growth trajectory of the crypt cell population in the first nine days of zebrafish development implicates a possible functional significance of crypt cells in early life stages of zebrafish.

Increase of S-100 protein-positive stellate cells in the anterior pituitary of chronic alcoholic patients with fatty liver or fatty cirrhosis.

Healthy subjects 40 years old were used as controls in a study of stellate cells (S-100 protein-containing cells, or S-100 cells) in subjects with chronic alcoholism and fatty liver or fatty cirrhosis. S-100 cells were sparsely found in the adenohypophysis of control subjects, and these cells sometimes formed small clusters. However, in chronic alcoholics with fatty liver or fatty cirrhosis, the number of stellate cells in the anterior pituitary tended to be 17 times higher than it was in the control group. No increase in the number of S-100 positive cells that constitute the large and small follicles in the intermediate pituitary. The physiological function of the S-100 protein has not yet been identified. The fact that an increase in prolactin-secreting and growth hormone-secreting cells, as well as a decrease in gonadotrophs were observed in the hypophysis of alcoholics suggests that the function of stellate cells may be closely related to these phenomena. Our results also imply that the stellate cells found in the anterior and intermediate pituitary differ in function although they both produce S-100 proteins.

Biochemical and Morphological Diversity among Folliculo-Stellate Cells of the Mink (Mustela vison) Anterior Pituitary

The folliculo-stellate (FS) cells are agranular cells of the anterior pituitary whose origin and function are still a matter of debate. This study examined the presence, topography, and morphological characteristics of FS cells in the mink anterior pituitary throughout the annual reproductive cycle. The S-100 protein was used as a FS cell marker. Immunoperoxidase labeling on tissue sections demonstrated the presence of two types of S-100 positive cells. Type 1 cells were stellate-shaped cells whose nuclei were localized near the center of pituitary follicles. In this type, S-100 labeling was strong in anterior pituitary sections obtained during spring, a period characterized by high prolactin pituitary content and low gonadotropin pituitary content. Type 2 cells were rounded cells occupying the periphery of the follicles. During periods of low prolactin pituitary content and high gonadotropin anterior content the type 2 S-100 positive cells formed aggregates of several cells. The total number of S-100 positive cells was constant during these two periods of the annual reproductive cycle, suggesting that type 1 and type 2 may reflect different morphological and physiological states of the same cell. Of the two subunits, α and β, that, combined, form three different dimeric S-100 proteins, mink FS cells expressed mostly the β subunit. FS cells also expressed the glial fibrillary acidic protein (GFAP). In culture, 8 ± 3% of anterior pituitary cells were S-100 positive. Cultured S-100 cells were elongated, polygonal, or rounded. The S-100 labeling accumulated in the cytoplasm around and within the nucleus, whereas it was weak in pseudopods and large cytoplasmic vacuoles. The presence of pseudopods suggests that cultured FS cells could migrate. The vacuoles may be related to the phagocytic activity ascribed to these cells. Some FS cells presented membrane blebbing and peripheral vesicles that were immunopositive for S-100 and that may indicate a secretory activity. Cultured FS cells possessed actin filaments organized as a peripheral network; a few actin cables were also observed running across the cytoplasm. Pseudopods depicted a highly organized actin network. The microtubules of FS cells expanded throughout the cytoplasm. The intermediate filaments expressed by cultured FS cells were GFAP and vimentin. GFAP labeling was punctate and vimentin was organized as filaments. All cultured S-100 cells were positive for vimentin, suggesting a mesenchymal origin for the cells, and all cultured S-100 positive cells were positive for GFAP, suggesting a neuroectodermal origin. In conclusion, S-100 positive cells are heterogeneous with respect to cell shape and expression of S-100 subunits in the mink anterior pituitary. The presence of morphologically different S-100 positive cells is modified in accordance with the endocrine status of the animal, suggesting that FS cells may be involved in the modulation of the anterior pituitary endocrine activity in the mink.

Gastrointestinal stromal tumors. An immunohistochemical study of cellular differentiation.

Forty-five benign and 11 malignant gastrointestinal stromal tumors (GIST) were immunohistochemically studied for the presence of desmin, muscle actins (MA) and S-100 protein. To facilitate the analysis, the tumors were divided into four groups by light microscopy: (1) typical leiomyomas comparable to peripheral leiomyomas (n = 9); (2) cellular spindle cell tumors (n = 29); (3) round cell tumors ("leiomyoblastomas" n = 7); and (4) sarcomas (n = 11). The typical leiomyomas were desmin- and MA-positive throughout, and showed well-differentiated smooth muscle cells by electron microscopy, similar to the normal gastric smooth muscle cells. All esophageal leiomyomas belonged to this group. Nineteen of 29 of the Group 2 tumors showed desmin positivity and 20 of 29 showed MA positivity, but usually only in less than 10% of the tumor cells, and in many instances it was very difficult to determine whether the positive cells were real tumor cells or entrapped muscle cells. Only 5 of 29 of Group 2 tumors showed widespread desmin positivity and 11 of 29 showed similar MA positivity. Of round cell tumors, only 1 of 7 showed desmin-positive cells and 3 of 7 MA-positive cells. None of the sarcomas showed desmin, while MA positivity was found in 6 of 11 cases, often in a large number of tumor cells. Seven tumors showed a significant number of S-100 positive tumor cells, but four of these also showed a high number of desmin- and MA-positive cells, suggesting that these tumors represented complex proliferations of muscle and Schwann cell elements. Two purely S-100 positive benign probably Schwann cell-like tumors were found, both in the small bowel. Small number of S-100 positive cells were commonly found in GIST, and these probably represented entrapped Schwann cells, because many tumors showed simultaneous proliferation of non-neoplastic nerves.

Demonstration of S-100 protein in sustentacular cells of phaeochromocytomas and paragangliomas.

Eighteen phaeochromocytomas, including both sporadic and familial cases, four cervical paragangliomas, two jugular paragangliomas, and one abdominal paraganglioma were examined immunohistochemically for the presence of S-100 protein. Positive staining in cells morphologically similar to the sustentacular cells of normal paraganglia and adrenal medulla were found in all paragangliomas and in the benign and aggressively growing phaeochromocytomas. In the two malignant tumours no positive reaction was demonstrated. In one tumour the sustentacular cells were shown to contain glial fibrillary acidic protein further supporting their Schwann cell relationship. The number of S-100 positive cells varied considerably. They demonstrated a spindle celled or elongated configuration with long slender processes. The nature of the sustentacular cell proliferation, neoplastic versus reactive, is discussed.

Malignant peripheral nerve-sheath tumors (malignant schwannomas). An immunohistochemical study of 29 cases.

Twenty-nine cases of malignant schwannoma consisted of three groups; 11 tumors associated with von Recklinghausen's disease (group I), nine tumors arising grossly from nerve trunks (group II), and 11 tumors so diagnosed basically on the histologic features (group III). Using the immunoperoxidase methods, the tumors were investigated with regard to S-100 protein, keratin, and epithelial membrane antigen (EMA). Approximately one-third of the cases (10 of 29) were devoid of S-100 positive cells and the remaining two-thirds (19 of 29) contained positive cells, with variable frequencies. The number of S-100 positive cells differed, depending largely on the presence or absence of neurofibroma-like areas in the tumor. The positive cells were rarely found in the group III tumors, which were neither associated with von Recklinghausen's disease nor connected to nerve trunks, even when their histologic features were unequivocal. Certain specific organoid structures in the tumor, such as neuroid or tactoid ones, were positive for S-100 protein. In one of the two malignant epithelioid schwannomas, the tumor cells were strongly positive for S-100 protein, thereby suggesting melanocytic differentiation. This tumor was interpreted as a melanocytic malignant schwannoma rather than a malignant melanoma, based in part on the fact that the overlying epidermis was uninvolved in this patient with von Recklinghausen's disease. True epithelial differentiation in one case of glandular schwannoma was verified by the positive stain of EMA along the inner surface of the glandular element.