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PubMed1988

The postnatal changes in the density of sensory nerve endings in the oral mucosa of the cat.

The changes that occur in the distribution and density of the encapsulated endings and Merkel cell-neurite complexes of the lingual gingival and alveolar mucosa of the mandible of kittens from birth to 28 d of age were observed through the use of methylene blue vital staining. The distribution of encapsulated endings showed a tendency to increase over the total area of the mucosae, but Merkel cell-neurite complexes tended to group into bands across the gingivae. While the density of the nerve endings of the former showed a continuous increase over the time period from the day of birth, when they totalled 13/cm2, to the 28th d by which that figure had increased to 144/cm2, the latter showed no such marked increase, totalling only 35/cm2 and 50/cm2, respectively. Further observations were made of the ultrastructures of organized endings in adult cat.

Animals↗
PubMed1981

[Pinkus' trichodiscoma (author's transl)].

The trichodiscoma first described by Pinkus (1966) is a small cutaneous tumor of the human retropilar hair disk; these lesions generally multiple and probably more common than previously appreciated occur in adult patients most often associated with perifollicular fibromas and acrochordons. We observed 2 female patients (39 and 47-year-old) with multiple trichodiscomas; a linear group of 7 tumors on the scalp in the first and multiple lesions disseminated on the chest in the second. Histologically and--in one case--electronmicroscopically the most striking features are: the paucity of the Merkel's cells in the overlying basal layer of the epidermis, the hyperplasia of the capillary blood vessels and of their endothelial cells, the presence of thick myelinated nerve fibers in the depth of the lesion but not in the vicinity of the epidermis, the proliferation of a loose dermal connective tissue, the occurrence of sparse hair follicles connected to the trichodiscoma but frequently located on its margin. One can conclude that trichodiscoma mainly consists of a hyperplasia of the dermal components of the hair disk; Merkel's cells though belonging to the normal hair disk are not involved in the histogenesis of the tumour. In his comprehensive paper (1974), Pinkus predicted that the description of the trichodisoma will lead to the identification of patients having only one or a few lesions: our first case may be considered as a circumscribed paucilesional clinical form.

Adult↗
PubMed1992

Recent advances and controversies concerning adnexal neoplasms.

This article reviews the diagnostic clinical and histologic features of a group of adnexal tumors, including papillary eccrine adenoma, adenoid cystic carcinoma, Merkel's cell carcinoma, aggressive digital papillary adenoma (and adenocarcinoma), Bowen's disease, intraepidermal epithelioma, microcystic adnexal carcinoma and related tumors, and subcutaneous trichoepithelioma. These are adnexal tumors either often not recognized, because of their rarity, or the origin, biologic potential, and classification of which have been controversial.

Adenocarcinoma, Papillary↗
PubMed1995

Localization of serotonin in taste buds: a comparative study in four vertebrates.

To investigate monoaminergic synaptic mechanisms in taste buds, we examined taste buds of mice, rats, rabbits, and mudpuppies for the presence of the neurotransmitter candidate, serotonin. Immunocytochemistry revealed serotonin-like immunostaining in cells in mammalian taste buds and Merkel-like basal cells in taste buds of mudpuppies. In untreated mudpuppies and in mammals injected with the precursor to serotonin, L-tryptophan, certain taste cells showed serotonin-like immunoreactivity, although in mammalian taste buds the immunostaining was relatively weak. After pretreating mammals with 5-hydroxytryptophan (5-HTP), the intermediate precursor between L-tryptophan and serotonin, several taste cells showed strong immunoreactivity for serotonin. These findings indicate that mammalian taste cells normally contain serotonin and that taste cells can take up 5-HTP and convert it to serotonin. Immunocytochemistry on wholemount preparations demonstrated that serotonergic cells of mudpuppies (i.e., Merkel-like basal cells) were disposed in a ring at the periphery of taste buds. Similarly, serotonergic cells in mammalian taste buds tended to be located at the periphery of taste buds. Based on the position of serotonergic cells in the taste bud and on recent physiological studies on the actions of serotonin in taste buds, we postulate that serotonin functions as a neuromodulator or neurotransmitter in vertebrate taste buds.

Animals↗
PubMed1997

Aggressive skin cancers in a cardiac transplant recipient.

Skin cancers following cardiac transplantation are a serious problem that may lead to significant morbidity and mortality. While the majority of skin cancers represent minimally invasive lesions that are treated adequately by local means, a small subset exhibits a potentially life-threatening natural history. The aggressiveness of these skin cancers, despite standard treatment, is indicative of the aggressive nature displayed by a subset of secondary malignancies following cardiac transplantation. The need for lifelong maintenance immunosuppression after transplantation is a major factor in the development of these secondary malignancies. Presented here is the case study of a cardiac transplant recipient who developed multiple aggressive squamous and non-squamous cell scalp skin cancers.

Carcinoma, Merkel Cell↗
PubMed2002

Elemental sulphur and alkali elutable melanin detected in oral melanosis and malignant melanoma by energy-filtering transmission electron microscopy.

BACKGROUND: The morphology and contents of melanosomes are important features for differentiating melanocyte-derived melanotic lesions such as melanosis and malignant melanoma. METHODS: In this study, we attempted to elucidate the structure of melanin and sulphur content in oral melanosis and malignant melanomas by ultrastructural analysis. RESULTS: In oral melanosis, the essential pathological findings were overproduction of eumelanin and discharge of melanin into keratinocytes. In malignant melanoma in situ, pleomorphic and ellipsoid abnormal melanosomes with an increase in sulphur content and alkali elution rate were detected. In invasive malignant melanoma, the irregular ellipsoid and spheroid melanosomes existing either as discrete bodies or compound melanosomes with furtherly increased sulphur content and alkali elution were detected. CONCLUSIONS: Our findings suggest that abnormal melanosome morphology and high sulphur content are predictive markers for assessment of early or precancerous melanotic lesions and malignant melanoma.

Alkalies↗
PubMed1993

A combined occurrence of neuroendocrine carcinoma of the skin and a benign appendageal neoplasm.

A 76-year-old Japanese male presented with a subcutaneous nodule in the dorsal cubital region of the right arm. The center of the nodule showed typical features of neuroendocrine carcinoma of the skin. The peripheral portion showed epithelial islands of squamoid cells with horn cysts suggestive of benign appendageal tumor with pilar differentiation. The coexistence of two skin neoplasms in the same lesion would suggest that both tumors developed from common pluripotential stem cell.

Aged↗
PubMed1995

Structure and innervation of the sensory organs on the snout of the star-nosed mole.

The star-nosed mole possesses a conspicuous specialization of its snout in the form of 22 fleshy appendages that fan out from around the nostrils. These appendages are used by the mole to explore its underground environment and are repeatedly brought into contact with objects of interest to the mole. This report describes the structure, innervation, and distribution of the sensory organs on the star of the star-nosed mole and briefly describes the behavioral use of the star. Each of the 22 appendages of the star is covered with a continuous array of Eimer's organs. These sensory receptors are modifications of the epidermal surface that take the form of bulbous papillae. Each Eimer's organ contains a column or stack of epidermal cells accompanied by nerve processes that originate from myelinated fibers in the underlying dermis. These neural processes travel through the cell column and form terminal swellings just below the outer layer of keratinized epidermis. Each Eimer's organ also contains a single Merkel cell-neurite complex within the cell column and a single lamellated corpuscle immediately below the cell column in the connective tissue of the dermis. There are approximately 30,000 Eimer's organs on the snout of this mammal, making this structure perhaps the most sensitive tactile organ yet discovered for its size. The segregation of these organs to individual appendages, not unlike the fingers of primates, affords an intriguing model for the study of somatosensory systems in mammals.

Animals↗
PubMed1987

Urothelial leukoplakia: new aspects of etiology and therapy.

We describe 3 women in 1 family who had systemic urothelial leukoplakia with no underlying pathological condition of the urinary tract. Irritative clinical symptoms resolved, and the macroscopic and microscopic appearance improved after 6 months of therapy with sodium pentosanpolysulfate. Electron microscopy showed special cells in the basal layer of the cornified squamous epithelium that also have been found in the trigone of women with so-called squamous metaplasia. Their similarity to Merkel's cells of the skin supports the theory that ectodermal cells are misplaced during embryogenesis. Genetic factors and sex hormones seem to influence the development of certain variants of squamous epithelium within the urinary tract.

Adult↗
PubMed1987

S100 protein immunoreactivity in poorly differentiated carcinomas. Immunohistochemical comparison with malignant melanoma.

This study compares the immunoprofiles of 25 cutaneous and mucosal melanomas with those of 400 poorly differentiated carcinomas, using a polyclonal antiserum to S100 and murine monoclonal antibodies to keratin (KER) and epithelial membrane antigen (EMA). All malignant melanomas expressed S100 but lacked reactivity for KER and EMA. Conversely, all of 49 carcinomas (12%) that displayed S100 also exhibited positivity for both epithelial markers. The latter group of tumors included 17 carcinomas of the breast, 16 eccrine sweat gland carcinomas, five high-grade salivary glandular adenocarcinomas, four lung cancers, three pancreatic ductal carcinomas, two serous ovarian carcinomas, one clear cell adenocarcinoma of the bladder, and one uterine cervical squamous carcinoma. None of 32 epithelial neoplasms that lacked both KER and EMA (19 testicular seminomas, four hepatocellular carcinomas, eight adrenocortical carcinomas, and one Merkel's cell carcinoma) contained S100 protein. These results suggest that S100 protein is relatively nonspecific as a single immunodeterminant in the diagnostic separation of melanoma and anaplastic carcinoma. The concomitant use of stains for EMA and KER, however, obviates this problem. Finally, since it is somewhat restricted in distribution, S100 reactivity in a known carcinoma may be of some use in predicting possible primary sources for a metastasis of unknown origin.

Carcinoma↗
PubMed1997

Histochemistry of the human hair follicle.

Immunohistochemistry of the human hair follicle is of increasing interest in hair research. The data on antigen distribution in the different epithelial and mesenchymal structures of this unique skin appendage are superfluous now. In the present chapter, I will concentrate on selected aspects related to hair follicle differentiation, epithelial-mesenchymal interactions, proliferation and metabolic activity. Hair diseases are common. Not unusually, hair growth and structure reflect systemic disturbances. Basic knowledge of hair anatomy and histochemistry is required for their rational evaluation. Immunohistochemistry is a valuable tool for microanatomy of the hair apparatus. It offers a link between the biochemical data and structural components of hair follicles, which may help to better understand physiology of hair growth and hair diseases.

Antigens↗
PubMedDate not supplied

[Primary neuroendocrine carcinoma of the skin: histologic, immunohistochemical and ultrastructural study of a case with highly aggressive biological behavior].

We report a histological, immunohistochemical and ultrastructural study of a case of neuroendocrine carcinoma of the skin, which occurred in a 52 years old woman in the dermal, subcutis and soft tissues of the left buttock. Clinically this neoplasm, which was related to intramuscular injections and a to a following abscess, had rapidly reached unusual dimension compared with other cases of neuroendocrine carcinoma of the skin reported in the literature. The patient died three months after presentation with distant metastases. A variable percentage of the neoplastic cells was positive for low molecular weight cytokeratins (CK), neurofilaments (NF), neuron specific enolase (NSE) and occasionally for vaso-intestinal polypeptide (VIP). Ultrastructural investigations showed two types of neoplastic cells, identified for some features of the nucleus and of the cytoplasm; these two groups of cells are, in our opinion, related to different stages of cellular development. Our results, in agreement with some observations reported in the literature, give evidence of a possible origin of neuroendocrine carcinoma of the skin from an undifferentiated cell which is capable of neuroendocrine or ectodermal differentiation.

Abscess↗
PubMed2005

Extrapulmonary small cell carcinoma.

This article reviews the recent literature on extrapulmonary small cell carcinomas. Until now, only four cases have been published in the English literature, two of those in the Southern Medical Journal. Sharing the information on diagnosis and treatment of these cases is important for better understanding and treatment of these patients. The differential diagnosis of pleural masses and the relation to asbestos exposure is briefly discussed. In addition, the available literature on other extrapulmonary localizations of small cell carcinoma is reviewed. The focus is on the available larger series of patients. Small cell carcinoma of the skin is included. This form of small cell carcinoma is often excluded from the larger review series, but can be an important alternative in the diagnostic process of patient evaluation.

Aged↗
PubMedDate not supplied

Ovarian small cell tumors: an electron microscopic review.

Small cell tumors of the ovary are uncommon but represent an important group to recognize in the differential diagnosis of primary and metastatic ovarian neoplasms. In some cases the correct diagnosis cannot be confidently made on the basis of clinical setting, routine light microscopy, and immunohistochemistry, and electron microscopy may be supportive or definitive in establishing cell type. The cell type is often important in choosing optimal therapy and in predicting prognosis. The authors performed electron microscopy on a moderate number of ovarian small cell tumors and here describe and illustrate the diagnostic features of representative examples of various types. The ultrastructural features of the metastatic tumors, such as embryonal rhabdomyosarcoma, neuroblastoma, and melanoma, are identical to those of their respective primary tumors, are well known, and usually pose no problem in diagnosis. On the other hand, the ultrastructural features of some primary ovarian small cell tumors may present a more difficult differential diagnosis, because they have features that are subtle and/or in common. Exemplary of tumors in this category are diffuse adult granulosa cell tumor, endometrial stromal sarcoma, and small cell carcinomas of the hypercalcemic and pulmonary (oat cell) types. Distinguishing among them may be difficult but is possible, and electron microscopy may be a valuable supplement to the diagnostic information obtained from the clinical presentation, light microscopy, immunohistochemistry and, in some tumors, cytometric analysis of these neoplasms.

Carcinoma, Merkel Cell↗
PubMed2005

Genetic evidence for selective neurotrophin 3 signalling through TrkC but not TrkB in vivo.

Neurotrophins control neuronal survival in a target-derived manner during the period of naturally occurring cell death in development. The specificity of this mechanism has been attributed to a restricted spatio-temporal expression of neurotrophin ligands in target tissues, as well as a selective expression of their cognate tyrosine kinase (Trk) receptors in different neuronal subpopulations. However, several in vitro and in vivo studies of null mutant mice have suggested that neurotrophin 3 (NT 3) also signals through the non-preferred TrkB receptor. In this study, we have directly addressed the in vivo preference of NT 3 to signal through TrkB or TrkC, by crossing the NT 3 knock-in mice (BDNF(NT 3/NT 3) mice) with the TrkB- or TrkC-null mutant mice. We find that TrkB is dispensable, whereas TrkC is required for the neuronal rescue by the NT 3 allele in the brain-derived neurotrophic factor- and NT 3-dependent cochleovestibular system. Our results show that NT 3 maintains survival of cells as well as target innervation only through interactions with TrkC in vivo. TrkB and TrkC receptors are thus not functionally redundant for NT 3, even when coexpressed in neurons of the cochleovestibular system.

Adaptor Proteins, Signal Transducing↗