Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cytodifferentiation in many melanocytic cells is regulated through the adenylate cyclase-cAMP pathway. To analyse the molecular changes associated with this process we have compared the proteins produced by two closely related cell lines which, though derived from a single cell line, respond very differently to modulation of this signalling pathway. The human melanoma cell line DX3 shows little change in in vitro characteristics following treatment with cAMP elevating agents; in contrast the more malignant DX3 LT5.1 variant, derived from the DX3 parental line, shows pronounced dendrification, decreased proliferation and a reduction in metastatic capacity after similar treatment. The two cell lines were treated with phosphodiesterase inhibitors for 5 days and then processed for two-dimensional gel characterization using an immobilized pH gradient for the IEF dimension. Proteins were detected by silver staining the gels and protein intensities were digitized using a laser densitometer. Two-dimensional gel patterns were edited, matched and a melanoma protein database of 637 spots constructed using PDQUEST software on an Orion 1/05 computer. Eleven proteins were lost and four new proteins were detected in both cell lines following treatment. Twenty-two proteins were present in DX3 LT5.1 after treatment but not in untreated lines or treated DX3. These differentially expressed proteins may be associated with the observed changes in differentiation patterns and metastasis. Our results illustrate the resolving power of this technique and suggest potential applications to the study of cellular differentiation.
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PMID:Changes in protein expression during melanoma differentiation determined by computer analysis of 2-D gels. 206 Jan 82

Cytologic specimens of neuroendocrine tumors metastatic to the liver were examined with regard to their silver staining properties after the application of argentaffin and argyrophil staining techniques (Masson, Grimelius and Sevier-Munger). In tumors with a content of serotonin (small intestine carcinoids), the presence of this substance was demonstrated cytologically as an argentaffin reaction in individual tumor cells; however, formalin fixation was a prerequisite for positive staining. Melanin in malignant melanoma cells displayed a positive argentaffin reaction, irrespective of the fixation used (air drying, formalin, Bouin's fluid or acetone-alcohol). Thus, serotonin and melanin can be distinguished in cytologic samples of neuroendocrine tumors by the use of the Masson argentaffin reaction with different fixatives. The nonargentaffin-positive neuroendocrine tumor cells were weakly stained or unreactive with the Grimelius argyrophil technique. The Sevier-Munger argyrophil technique was negative or gave a disturbing nonspecific background staining reaction that was difficult to interpret in the cytologic samples. Thus, the Grimelius method appears to be the most useful silver stain for identifying neuroendocrine tumor cells in cytologic material, irrespective of their hormone content, since both argentaffin-positive and argentaffin-negative cell samples were stained at least to some degree.
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PMID:Application of silver stains to cytologic specimens of neuroendocrine tumors metastatic to the liver. 241 33

The technique of silver (Ag) staining of nucleolar organizer region-associated proteins (AgNORs) has been shown to be of value in differentiating between benign and malignant cells. We have studied 33 borderline melanocytic lesions, in which a diagnosis of melanoma had been seriously considered, in order to assess the value of this technique in a commonly encountered diagnostic situation. We found that benign naevus cells possessed single compact or granular AgNORs, whereas some malignant melanocytes possessed large, often loosely arranged groups of AgNORs. However, the pattern of AgNORs observed in melanocytes of some atypical but benign lesions was also seen in some melanomas. The differential diagnosis of borderline melanocytic lesions is not clarified by use of the AgNOR technique.
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PMID:The value of nucleolar organizer region staining in the differential diagnosis of borderline melanocytic lesions. 246 98

A new and sensitive method of staining melanocytic lesions is described. Tissue sections covered by a solution of colloidal silver nitrate are exposed to microwaves for 45 sec in a domestic oven to produce clean, crisp staining of melanocytes and melanoma cells, often showing long delicate dendritic cell processes. The staining technique does not stain other pigments or argyrophilic tissues and is shown to be more sensitive than the standard Masson-Fontana procedure.
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PMID:A new, rapid, microwave-stimulated method of staining melanocytic lesions. 247 20

A 24 year-old male with painful swelling over the right side of his palate for about two weeks was presented. An incisional biopsy was performed. In a routine hematoxylin and eosin examination by light microscopy, spindle and epithelioid cells with a bizarre appearance were discernible in the submucosal area. A pagetoid pattern was found in areas of the epithelium. Since this is not a remarkable finding, further examinations, such as the Trichrome-Masson and silver stain, immunohistochemistry using cytokeratin, vimentin, S-100, leukocyte common antigen, factor VIII, and alpha-1-antichymotrypsin detection kits, and electron microscopy were all carried out. According to the histological pattern of cells and the positive findings from the special stains, immunohistochemistry, and electron microscopy, a diagnosis of desmoplastic amelanotic melanoma was made. This variant of melanoma is a rare disorder with unremarkable, non-specific clinical manifestations in the oral cavity, which makes the diagnosis of this disease more difficult. We, therefore, report one case of this disease. Owing to the fact that diagnosis of this variant was mainly based on the positive findings of vimentin and S-100 in the immunohistochemistry examination and intracellular premelanosome detected by electron microscopy, immunodiagnosis and electron microscopy seem to be essential for differential diagnosis.
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PMID:Desmoplastic amelanotic melanoma of palate: a case report with immunohistochemistry and electron microscopic studies. 248 64

Homogeneously staining regions (HSRs) in the human melanoma cell line, MeWo, are located on an X and a der(15) chromosome. These regions are homogeneously stained with quinacrine fluorescence, but stain differentially with conventional Giemsa, G-banding, C-banding, and distamycin A/4',6-diamidino-2-phenylindole. There are five and six blocks of positively staining material on the X and der(15) HSRs, respectively. Hybridization in situ with a cloned repetitive Kpn I family member has confirmed the amplification of this sequence along the HSRs. With silver staining of the nucleolar organizer regions (NORs) there appear to be three very strong and two weaker pairs of NORs along the HSR of the X chromosome and four strong and one weaker pair on that of the der(15) chromosome. There was little NOR staining on the normal acrocentric chromosomes in these cells, suggesting preferential transcription of the NORs in the HSRs. Centromere-dot staining revealed a distribution of multiple centromeres similar to the NORs along the two HSRs. These data suggest that a unit composed of the short arm and centromere of chromosome #15 has been amplified and that the HSR present on the X chromosome probably arose by a translocation from chromosome #15.
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PMID:Amplified sequences from chromosome 15, including centromeres, nucleolar organizer regions, and centromeric heterochromatin, in homogeneously staining regions in the human melanoma cell line MeWo. 257 90

The presence, densities, and patterns of distribution of melanocytes in the epidermis of human embryos and fetuses, ranging in age from 40 d to 140 d estimated gestational age (EGA), were studied using the HMB-45 monoclonal antibody that recognizes an antigen in melanoma cells and fetal melanocytes. Immunostained sections of skin and epidermal sheets revealed dendritic melanocytes within the basal or intermediate layers of 50 d EGA and older skin. Melanocytes could not be identified by immunostaining or electron microscopy in younger (40-50 d EGA) epidermis or in cultured epidermal cells from these specimens. However, skin from a 45 d EGA embryo grown in organ culture for 11 d stained positively with HMB-45, suggesting that melanocytes are present at the age either in the epidermis or dermis of the explant. Double-labeling experiments using ATPase and HMB-45 confirmed the specificity of HMB-45 for melanocytes and demonstrated that melanocytes and Langerhans cells are nonoverlapping populations. Melanocytes were present in the embryonic epidermis in relatively high numbers (mean value of approximately 1050 cells/mm2); they increased in density to approximately 2300 cells/mm2 during the late first trimester and early second trimester, then declined during later stages of development to a density of approximately 800 cells/mm2, within the range of values for the newborn child and young adult. Equivalent numbers of melanocytes were recognized by silver staining and with the HMB-45 antibody in an 87 d EGA test sample, indicating that HMB-45 reacted with the total melanocytic population. Melanocytes appeared to be distributed in epidermal sheets in a regular pattern. Statistical tests used to evaluate the randomness of a population revealed a tendency toward a non-random distribution in specimens younger than 80 d EGA, just prior to appendage formation and epidermal stratification into multiple layers, however there was variability in the degree of randomness for any given age. The results of this study have closed the gap in timing between the conclusion of neural crest formation and migration (around 6 weeks) and the appearance of melanocytes in the skin between 40-50 d EGA.
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PMID:The appearance, density and distribution of melanocytes in human embryonic and fetal skin revealed by the anti-melanoma monoclonal antibody, HMB-45. 261 87

We have isolated a repetitive 1.8 kb KpnI DNA sequence which is amplified in the homogeneously staining regions of a human melanoma cell line. Under low stringency conditions this sequence (D15Z1) hybridized in situ to the centromeric heterochromatin of chromosomes 1, 9, 15p, 16, and distal Yq as well as to the short arms of the other acrocentric chromosomes. Under conditions of high stringency, labelling was predominantly on the short arm of chromosome 15. D15Z1 was shown to be present at approximately 3,000 copies per haploid genome and organized in long tandem arrays showing restriction site heterogeneity. Sequences homologous to D15Z1 were highly enriched in the less dense shoulder region of a Ag+-Cs2SO4 gradient. Analysis of D15Z1 indicated that this sequence is composed of tandemly arranged imperfect repeats of the consensus 5' AATGG 3' similar to previously identified satellite III sequences. Digestion of D15Z1 with HinfI resulted in a series of restriction fragments making up a subset of the HinfI ladder components of satellites III and IV. These data suggest that D15Z1 represents a chromosome 15 specific domain of human satellites III or IV and that it makes up the major fraction of the heterochromatin of this chromosome. Possible relationships between this sequence and the cytochemical staining properties of human chromosomes with distamycin A/DAPI, D280/170, and antiserum to 5-methylcytosine are discussed.
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PMID:Organization of a repetitive human 1.8 kb KpnI sequence localized in the heterochromatin of chromosome 15. 299 9

The periodate-thiocarbohydrazide silver proteinate (PA-TCH-SP) method was used to study the envelopment process in varicella-zoster virus-infected human melanoma cells. Viral envelopment could be seen at two sites, the nuclear membrane and at virus-induced intracytoplasmic vacuoles. Virus-associated glycoconjugates were detected by the PA-TCH-SP method at the plasmalemma and on the inner membrane of the intracytoplasmic vacuoles. Virion envelopes acquired at the nuclear membrane were PA-TCH-SP negative, whereas those acquired at intracytoplasmic vacuoles were PA-TCH-SP positive. All virions found inside these vacuoles contained periodate-reactive envelopes. Release of virions into the extracellular space, where virtually all virions were PA-TCH-SP positive, appeared to be via exocytosis. Thus, the PA-TCH-SP method identifies glycoprotein incorporation at specific cytoplasmic vacuoles distinct from nuclear envelope, endoplasmic reticulum, and Golgi lamellae. These results suggest that envelopment within the cytoplasm is a stage in the assembly of the varicella-zoster virion.
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PMID:Varicella-zoster viral glycoprotein envelopment: ultrastructural cytochemical localization. 300 84

Nucleolar organizer regions (NORs) can be stained by a simple one-step silver technique; the black dots formed are termed AgNORs. Often AgNORs are tightly clustered, appearing as one silver-stained nucleolus (AgNu). We have assessed this technique as a possible prognostic indicator for thick (greater than 3.0 mm) primary cutaneous malignant melanoma (CMM). Three groups were studied: (A) seven thick CMM that had not metastasized 8-20 years after excision; (B) three thick CMM that developed metastases 6-9 years after excision; and (C) twelve CMM that presented with metastases or developed them within 4 years of excision. Two methods of counting silver-stained black dots in nuclei were employed: one method counted easily discernible black dots consisting of AgNus and dispersed AgNORs; the other attempted to count actual AgNORs both dispersed and clustered within AgNus. Scores per nucleus by the first method were 1.5-6.7 in group A, 1.1-2.6 in group B, and 1.4-5.4 in group C. AgNOR counts by the second method were 6.2-13.0 in group A, 5.4-8.9 in group B, and 5.3-10.5 in group C. No significant difference was present between groups for scores by either method. Due to the subjectively, technical difficulty, non-reproducibility, and tedium associated with the second method of attempting to count individuals AgNORs, the first method is recommended. It is concluded that this technique is of no value in predicting prognosis for CMM.
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PMID:Silver-stained nucleoli and nucleolar organizer region counts are of no prognostic value in thick cutaneous malignant melanoma. 320 53


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