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1.
China Journal of Chinese Materia Medica ; (24): 1606-1619, 2023.
Artigo em Chinês | WPRIM | ID: wpr-970633

RESUMO

This study aimed to evaluate the biological effect and mechanism of Vernonia anthelmintica Injection(VAI) on melanin accumulation. The in vivo depigmentation model was induced by propylthiouracil(PTU) in zebrafish, and the effect of VAI on melanin accumulation was evaluated based on the in vitro B16F10 cell model. The chemical composition of VAI was identified according to the high-performance liquid chromatography quadrupole-time-of-flight tandem mass spectrometry(UPLC-Q-TOF-MS). Network pharmaco-logy was applied to predict potential targets and pathways of VAI. A "VAI component-target-pathway" network was established, and the pharmacodynamic molecules were screened out based on the topological characteristics of the network. The binding of active molecules to key targets was verified by molecular docking. The results showed that VAI promoted tyrosinase activity and melanin production in B16F10 cells in a dose-and time-dependent manner and could restore the melanin in the body of the zebrafish model. Fifty-six compounds were identified from VAI, including flavonoids(15/56), terpenoids(10/56), phenolic acids(9/56), fatty acids(9/56), steroids(6/56), and others(7/56). Network pharmacological analysis screened four potential quality markers, including apigenin, chrysoeriol, syringaresinol, and butein, involving 61 targets and 65 pathways, and molecular docking verified their binding to TYR, NFE2L2, CASP3, MAPK1, MAPK8, and MAPK14. It was found that the mRNA expression of MITF, TYR, TYRP1, and DCT in B16F10 cells was promoted. By UPLC-Q-TOF-MS and network pharmacology, this study determined the material basis of VAI against vitiligo, screened apigenin, chrysoeriol, syringaresinol, and butein as the quality markers of VAI, and verified the efficacy and internal mechanism of melanogenesis, providing a basis for quality control and further clinical research.


Assuntos
Animais , Vernonia/química , Melaninas/metabolismo , Peixe-Zebra/metabolismo , Farmacologia em Rede , Simulação de Acoplamento Molecular , Apigenina/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Cromatografia Líquida de Alta Pressão
2.
Braz. dent. j ; 29(4): 400-404, July-Aug. 2018. graf
Artigo em Inglês | LILACS | ID: biblio-974165

RESUMO

Abstract Melanotic neuroectodermal tumor of infancy (MNTI) is a rare neoplasm that affects mainly children under 1 year of age. A 4-month-old boy was referred for evaluation of a lesion with 1 month of evolution. Intra-oral examination detected a firm upon palpation submucosal nodular mass, measuring 1.5 cm in diameter, affecting the anterior maxillary alveolar ridge and covered by a slightly blue mucosa with evident telangiectasia. The patient underwent an incisional biopsy and histological and immunohistochemical analyses revealed nests of AE1/AE3 positive epithelioid cells with abundant melanin pigmentation. Other cell types, resembling neuroblasts, were also present and positive for CD56, synaptophysin and enolase. The diagnosis of MNTI was established and the patient was referred for treatment. Conservative surgical resection was performed along with 3 adjacent teeth under general anesthesia. The patient is in follow-up for 1,5 year without recurrence. Conservative surgical management of MNTI may be an alternative to maxillectomy, contributing to the patient´s quality of life.


Resumo Tumor neuroectodérmico melanótico da infância (TNMI) é um neoplasma raro que afeta principalmente crianças com idade abaixo de 1 ano. Um menino de 4 meses foi referenciado para avaliação de uma lesão com 1 mês de evolução. O exame intra-oral detectou uma massa nodular submucosa firme à palpação, medindo 1,5 cm de diâmetro, afetando rebordo alveolar anterior da maxila e recoberta por mucosa de coloração levemente azulada com telangiectasia evidente. O paciente foi submetido à biopsia incisional e as análises histológica e imunohistoquímica revelaram ninhos compostos por células com abundante pigmento de melanina, positivas para AE1/AE3. Outro tipo celular, semelhante à neuroblastos, também estava presente e foram positivas para CD56, sinaptofisina e enolase. O diagnóstico de TNMI foi estabelecido e o paciente encaminhado para tratamento. Ressecção cirúrgica conservadora sob anestesia geral ao longo de 3 dentes adjacentes foi realizada. O paciente está em acompanhamento há 1 ano e meio sem sinais de recorrência. O tratamento cirúrgico conservador do TNMI pode ser uma alternativa à maxilectomia, contribuindo para a qualidade de vida do paciente.


Assuntos
Humanos , Masculino , Lactente , Tumor Neuroectodérmico Melanótico/diagnóstico , Biópsia , Imuno-Histoquímica , Tumor Neuroectodérmico Melanótico/cirurgia , Tumor Neuroectodérmico Melanótico/metabolismo , Tumor Neuroectodérmico Melanótico/patologia , Antígeno CD56/metabolismo , Melaninas/metabolismo
3.
Indian J Exp Biol ; 2015 Jun; 53(6): 380-387
Artigo em Inglês | IMSEAR | ID: sea-158514

RESUMO

Melanins are enigmatic pigments produced by a wide variety of microorganisms including bacteria and fungi. Here, we have isolated and characterized extracellular melanin from mushroom fungus, Schizophyllum commune. The extracellular dark pigment produced by the broth culture of S. commune, after 21 days of incubation was recovered by hot acid-alkali treatment. The melanin nature of the pigment was characterized by biochemical tests and further, confirmed by UV, IR, EPR, NMR and MALDI-TOF Mass Spectra. Extracellular melanin, at 100 µg/ml, showed significant antibacterial activity against Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae and Pseudomonas fluorescens and antifungal activity against Trichophyton simii and T. rubrum. At a concentration of 50 µg/ml, melanin showed high free radical scavenging activity of DPPH (2,2-diphenyl-1-picrylhydrazyl) indicating its antioxidant potential. It showed concentration dependent inhibition of cell proliferation of Human Epidermoid Larynx Carcinoma Cell Line (HEP-2). This study has demonstrated characterization of melanin from basidiomycetes mushroom fungus, Schizophyllum commune and its applications.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Antioxidantes/farmacocinética , Basidiomycota/química , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Fungos , Melaninas/biossíntese , Melaninas/isolamento & purificação , Melaninas/farmacocinética , Melaninas/metabolismo , Schizophyllum/química , Schizophyllum/classificação
4.
Journal of Veterinary Science ; : 135-143, 2015.
Artigo em Inglês | WPRIM | ID: wpr-44469

RESUMO

Tea contains polyphenols and is one of the most popular beverages consumed worldwide. Because most tyrosinase inhibitors that regulate melanogenesis are phenol/catechol derivatives, this study investigated the inhibitory effects of Camellia sinensis water extracts (CSWEs), including black tea, green tea, and white tea extracts, on melanogenesis using immortalized melanocytes. CSWEs inhibited melanin accumulation and melanin synthesis along with tyrosinase activity in a concentration-dependent manner. These inhibitory effects were superior to those of arbutin, a well-known depigmenting agent. The anti-melanogenic activity of black (fermented) tea was higher than that of a predominant tea catecholamine, epigallocatechin gallate. CSWEs, especially black tea extract, decreased tyrosinase protein levels in a concentration-dependent manner. These results suggest that the anti-melanogenic effect of CSWEs is mediated by a decrease in both tyrosinase activity and protein expression, and may be augmented by fermentation. Thus, CSWEs could be useful skin-whitening agents in the cosmetic industry.


Assuntos
Animais , Camundongos , Catequina/análogos & derivados , Linhagem Celular , Melaninas/metabolismo , Melanócitos/enzimologia , Monofenol Mono-Oxigenase/metabolismo , Extratos Vegetais/farmacologia , Folhas de Planta/química , Chá/química
5.
Rev. chil. infectol ; 31(1): 28-33, feb. 2014. ilus, graf, tab
Artigo em Espanhol | LILACS | ID: lil-706543

RESUMO

Background: Melanocytes are cells located in epidermis and mucous membranes that synthesize melanin and cytokines. It is known that melanin has antimicrobial activity and that melanocytes are melanized in presence of microbial molecules. Objective: To study the antifungal activity of melanin on Candida spp. Methodology: The minimum inhibitory concentration (MIC) to melanin was determined in 4 Candida ATCC strains (C. albicans SC5314, C. parapsilosis 22019, C. glabrata 2001, C. krusei 6258) and 56 clinical isolates of Candida spp. (33 C. albicans, 12 C. glabrata, 3 C. famata, 3 C. krusei, 3 C. parapsilosis, 2 C. tropicalis) using a broth microdilution method. In addition, the antifungal activity of melanocytes and mice melanoma cells was tested against C. albicans. Results: Melanin inhibited the tested isolates, including the susceptible dose-dependent and fluconazole-resistant strains; MIC range and MIC50 were 0.09-50 μg/mL and 6.25 μg/mL, respectively. Pigmented cells lysates inhibited C. albicans. Conclusions: Melanin is able to inhibit clinical isolates of Candida spp. Melanization could be an important protective mechanism of melanocytes.


Introducción: Los melanocitos son células presentes en piel y en mucosas que sintetizan melanina, además de citoquinas. Es sabido que melanina presenta actividad antimicrobiana y que los melanocitos se melanizan al ser expuestos a moléculas microbianas. Objetivo: Estudiar la actividad antifúngica de melanina en cepas clínicas de Candida spp. Metodología: Se midió la concentración inhibitoria mínima (CIM) a melanina, de 4 cepas de Candida ATCC (C. albicans SC5314, C. parapsilosis 22019, C. glabrata 2001 y C. krusei 6258) y 56 aislados clínicos de Candida spp. (33 C. albicans, 12 C. glabrata, 3 C. famata, 3 C. krusei, 3 C. parapsilosis, 2 C. tropicalis) mediante un método de microdilución en caldo. Además se estudió el efecto antifúngico de lisados de melanocitos y células de melanoma de ratón en C. albicans. Resultados: Melanina inhibió las cepas analizadas, incluso cepas susceptibles dosis-dependiente y resistentes a fluconazol, siendo los rangos de CIM y CIM50 de 0,09-50 μg/mL y 6,25 μg/ mL, respectivamente. Los lisados de células pigmentadas inhibieron C. albicans. Conclusiones: Melanina es capaz de inhibir cepas clínicas de Candida spp. La melanización podría ser un importante mecanismo protector de los melanocitos.


Assuntos
Animais , Camundongos , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Fluconazol/farmacologia , Melaninas/farmacologia , Melanócitos/imunologia , Candida albicans/classificação , Candida albicans/crescimento & desenvolvimento , Farmacorresistência Fúngica , Melaninas/metabolismo , Melanócitos/metabolismo , Melanoma Experimental/metabolismo , Melanoma Experimental/microbiologia , Pigmentação da Pele
6.
An. bras. dermatol ; 89(1): 11-25, Jan-Feb/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-703535

RESUMO

Cutaneous hyperpigmentations are frequent complaints, motivating around 8.5% of all dermatological consultations in our country. They can be congenital, with different patterns of inheritance, or acquired in consequence of skin problems, systemic diseases or secondary to environmental factors. The vast majority of them are linked to alterations on the pigment melanin, induced by different mechanisms. This review will focus on the major acquired hyperpigmentations associated with increased melanin, reviewing their mechanisms of action and possible preventive measures. Particularly prominent aspects of diagnosis and therapy will be emphasized, with focus on melasma, post-inflammatory hyperpigmentation, periorbital pigmentation, dermatosis papulosa nigra, phytophotodermatoses, flagellate dermatosis, erythema dyschromicum perstans, cervical poikiloderma (Poikiloderma of Civatte), acanthosis nigricans, cutaneous amyloidosis and reticulated confluent dermatitis.


Assuntos
Humanos , Masculino , Feminino , Pele/patologia , Hiperpigmentação/patologia , Dermatopatias/etiologia , Dermatopatias/patologia , Dermatopatias/terapia , Hiperpigmentação/etiologia , Hiperpigmentação/terapia , Diagnóstico Diferencial , Melaninas/metabolismo
7.
Artigo em Inglês | IMSEAR | ID: sea-157460

RESUMO

Background: Under Eye Dark Circles is attributed to multiple factors. The treatment should address the various pathologies involved to provide the best possible effects. Aims: To assess the efficacy and safety of Wunder eye cream (a combination of 3% Biophytex LS 8740 and 5% Proteasyl TP LS 8657) in patients with under eye dark circles. Study Design: Open label, prospective, single arm and multicentric post marketing surveillance clinical study. Materials and Methods: 142 patients (125 males and 17 females) were evaluated in the study. Wunder Eye cream was applied twice daily on the affected under eye dark circle area for eight weeks. Parameters evaluated were area of under eye pigmentation, improvement in luminance of under eye skin, reduction in under eye puffiness and reduction in under eye wrinkles using a digital camera photographs after four and eight weeks of treatment. Safety evaluation was also done on the same time. The values were compared using Chi-Square test. Results: Early response was seen in 40% of patients with four weeks of treatment where 50% improvement in all the parameters was seen. With eight weeks of therapy about 92.3% of patients showed 50 to 100% improvement in the area of under eye pigmentation; 50% to 75% improvement was seen in 87.3% of patients for under eye pigmentation, in 80.1% patients for luminance of under eye skin, in 68% patients for under eye puffiness and in 67.4% of patients for under eye wrinkles. Conclusion: Wunder eye cream is a combination of botanical and yeast extracts was found to be effective against under eye dark circles.


Assuntos
Adulto , Combinação de Medicamentos , Pálpebras , Feminino , Humanos , Hiperpigmentação/tratamento farmacológico , Masculino , Melaninas/metabolismo , Pomadas/administração & dosagem , Pomadas/uso terapêutico , Órbita , Extratos Vegetais , Envelhecimento da Pele/tratamento farmacológico
8.
Artigo em Inglês | IMSEAR | ID: sea-139949

RESUMO

Background: One of the major direct or indirect targets of ultraviolet exposure of skin is the melanocyte or the melanin -forming cell. Epidermal melanocytes act as a trap for free radicals. Based on the protective role of melanocytes in medical literature, the role of melanin pigmentation in gingiva needs to be elucidated. Periodontal pathogens and their products demonstrate the ability to induce the generation of reactive oxygen species. Hence purpose of this study was to unravel the protective role of melanin (if any) against the gingival inflammation. Materials and Methods: A total of 80 subjects; 20 in each group were selected. The selection of subjects regarding gingival pigmentation was based on Dummett's scoring criteria 0, 3. A complete medical, dental history and an informed consent were obtained from the patients. After evaluation of clinical parameters the GCF was collected using microcapillary pipettes at the selected sites. IL-1β levels were quantitated using ELISA. Results: In non-pigmented healthy and gingivitis groups, there was a positive correlation between plaque index, gingival index and bleeding index versus IL-1β level: indicating an increase in the biochemical mediator of inflammation corresponding to an increase in the clinical parameters of inflammation. Also a positive correlation was found between the gingival index and bleeding index versus the IL-1β levels in the pigmented healthy group. The pigmented gingivitis groups showed a negative correlation between the plaque index, gingival index and bleeding index. Conclusions: The clinical markers of inflammation such as gingival index, bleeding index was of low numerical value in pigmented group than in the non-pigmented group, supposedly due to the protective action of melanin. The negative correlation of clinical markers of inflammation to the IL-1β levels in the pigmented gingivitis group could possibly be attributed to the protective role of melanins.


Assuntos
Adolescente , Adulto , Antioxidantes/metabolismo , Estudos de Casos e Controles , Feminino , Gengiva/imunologia , Gengiva/metabolismo , Gengivite/imunologia , Gengivite/metabolismo , Humanos , Interleucina-1beta/imunologia , Interleucina-1beta/metabolismo , Masculino , Análise por Pareamento , Melaninas/imunologia , Melaninas/metabolismo , Pessoa de Meia-Idade , Índice Periodontal , Pigmentação/imunologia , Espécies Reativas de Oxigênio , Valores de Referência , Estatísticas não Paramétricas , Adulto Jovem
9.
Indian J Dermatol Venereol Leprol ; 2007 Nov-Dec; 73(6): 417-9
Artigo em Inglês | IMSEAR | ID: sea-51977

RESUMO

A 5-year-old boy was admitted for severe neurological impairment including hypotonia and loss of consciousness without preceding febrile illness. On examination, he had silver colored hair and bronze-tan over photo-exposed body parts. He was born of consanguineous parents and three of his elder siblings, who died in early childhood, had similar colored hair. Complete blood count and serum immunoglobulin levels were within normal limits. Peripheral blood smear did not show any cytoplasmic granules in neutrophils. Cerebro-spinal fluid examination did not reveal any abnormality. Light microscopic examination of the hair revealed irregular clumping of the melanin throughout the shafts. The patient died on the second day following admission. A clinical diagnosis of Elejalde disease was made. The clinical and genetic overlapping of the three silvery-hair syndromes has been discussed.


Assuntos
Pré-Escolar , Consanguinidade , Cabelo/anormalidades , Humanos , Masculino , Melaninas/metabolismo , Hipotonia Muscular/etiologia , Síndromes Neurocutâneas/diagnóstico , Transtornos da Pigmentação/diagnóstico , Inconsciência/etiologia
10.
Indian J Pathol Microbiol ; 2005 Apr; 48(2): 243-4
Artigo em Inglês | IMSEAR | ID: sea-74307

RESUMO

A case of 7 yr old boy with cerebellar melanotic medulloblastoma is reported. Melanotic medulloblastoma is a variant of medulloblastoma, which shares some of the histological features of Melanotic neuroectodermal tumor of infancy. However the predominant histological pattern and clinical behavior is that of conventional or classical medulloblastoma. The melanin pigments present in these tumors have been proved to be both neuromelanin and oculocutaneous type of melanin. This is a rare histological type and only few cases have been reported in the literature so far.


Assuntos
Neoplasias Cerebelares/patologia , Cerebelo/patologia , Criança , Humanos , Masculino , Meduloblastoma/patologia , Melaninas/metabolismo
11.
Indian J Pathol Microbiol ; 2004 Jan; 47(1): 22-3
Artigo em Inglês | IMSEAR | ID: sea-74869

RESUMO

A 30 year old nulligravidfemale attended gynaecological OPD for investigation of primary infertility. Local examination revealed presence of a dark pigmented area in the posterior lip of the cervix. The biopsy from cervix showed, squamous metaplasia of the lining epithelium with presence of granules of melanin pigment in the basal layer. Schmorl's stain for melanin and immunohistochemical staining for S-100 and HMB-45 showed strong positivity in these cells. Melanosis of the uterine cervix is usually an incidental finding in females with uterine prolapse in their fifth and sixth decade. The origin of melanin containing cells in the uterine cervix is debatable till date. Amongst the various possibilities for the origin of these cells in the uterine cervix, neural origin is probably more acceptable than epithelial cell origin. The combined expression of melanocytic and Schwanian markers in the index case, suggest a biphasic differentiation of melanin containing cells in the uterine cervix. Although the exact histogenesis and clinical significance of these are still unknown, a long term follow-up is needed to study the nature of these lesions to look for any precursor lesion for development of malignant melanoma.


Assuntos
Adulto , Colo do Útero/citologia , Feminino , Humanos , Melaninas/metabolismo , Melanócitos/citologia , Melanose/metabolismo , Proteínas S100/metabolismo
12.
Journal of Korean Medical Science ; : 648-654, 2002.
Artigo em Inglês | WPRIM | ID: wpr-72665

RESUMO

Stasis dermatitis is an itchy, scaly, and hyperpigmented condition of the lower leg due to venous insufficiency. Hemosiderin and/or melanin have been considered responsible for the brown pigmentation. However, there are not sufficient histopathologic studies. In this retrospective study the hospital records and biopsy slides of 20 patients were reviewed to determine the pathogenetic mechanisms of brown pigmentation in stasis dermatitis. Fifteen were men (75%) and 5 were women (25%) with a mean age of 46.2+/-8.2 yr (18-76), mean age at onset of 43.4+/-18.0 yr (17-73), and a mean duration of the disease 2.8+/-2.5 yr (0.25-10). All patients had varicose vein and complained of pruritus. On histopathologic evaluation, two cases out of 20 (3 skin biopsy specimens from 25 samples) showed dermal melanocytes containing melanin, and incontinence of melanin pigment was observed in 5 cases, which indicates that melanin pigments from epidermis could contribute to cutaneous pigmentation in stasis dermatitis. However, the existence of dermal melanocytes in two cases cannot be explained because normally the dermis contains no melanocytes. Further studies concerning the role of iron or inflammatory cytokines on the development of dermal melanocytes should be conducted.


Assuntos
Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dermatite/etiologia , Derme/metabolismo , Hiperpigmentação/etiologia , Dermatoses da Perna/etiologia , Melaninas/metabolismo , Melanócitos/metabolismo , Insuficiência Venosa/complicações
13.
Dermatol. rev. mex ; 39(2): 81-4, mar.-abr. 1995. tab, ilus
Artigo em Espanhol | LILACS | ID: lil-151926

RESUMO

Se hace una revisión de los cambios de color del pelo así como de sus mecanismos fisiopatogénicos. Se mencionan las causas genéticas y adquiridas, así como metabólicas e inmunológicas, por fármacos y ambientales


Assuntos
Humanos , Relação Dose-Resposta a Droga , Exposição Ambiental/efeitos adversos , Cor de Cabelo , Queratinas/deficiência , Melaninas/genética , Melaninas/metabolismo , Melaninas/fisiologia , Metabolismo , Monofenol Mono-Oxigenase/deficiência , Monofenol Mono-Oxigenase/imunologia , Monofenol Mono-Oxigenase/fisiologia
14.
P. R. health sci. j ; 12(2): 129-35, jun. 1993.
Artigo em Inglês | LILACS | ID: lil-176726

RESUMO

Based on previous findings that lens pigments and melanins share many physicochemical properties, human lens pigments and natural (hair) and synthetic melanins were submitted to oxidation with permanganate under strong acidic conditions. This procedure has been utilized for the characterization of melanins and results in the well defined products, thiazole-4,5-dicarboxylic acid (TDCA) and pyrrole-2,3,5-tricarboxylic acid (PTCA), which can be quantitated by high performance liquid chromatography (HPLC). PTCA is regarded as a marker of black eumelanins and was therefore a main component of synthetic DOPA-eumelanin and dark hair. Its identity was established by synthesis from 5-hydroxyindole-2-carboxylic acid. TDCA derives from pheomelanins and was therefore an important component of red hair and synthetic GSH-pheomelanin. TDCA was identified by its retention time relative to PTCA. The analysis of a series of cataract digests of increasing pigmentation (type I < type IV < type V) and a purified fraction of lens pigments (DE52 pigment) revealed the presence in these preparations of both PTCA and TDCA. The concentration of TDCA significantly increased with the degree of pigmentation of the digests and reached a maximum in the DE52 pigment. The TDCA/PTCA ratio was high in the lens preparations and comparable to that given by hair pheomelanin. These findings support that pheomelanin is an integral part of lens pigments. By comparing the yields of TDCA in GSH-pheomelanin and in the purified lens pigment, a 9 per cent contribution of pheomelanin to the lens pigment was estimated


Assuntos
Ácidos Dicarboxílicos/análise , Cristalino/química , Melaninas/análise , Pirróis/análise , Tiazóis/análise , Ácidos Dicarboxílicos/metabolismo , Catarata/metabolismo , Cromatografia Líquida de Alta Pressão , Cristalino/metabolismo , Melaninas/metabolismo , Pigmentos Biológicos/análise , Pigmentos Biológicos/metabolismo , Pirróis/metabolismo , Tiazóis/metabolismo
15.
Indian J Physiol Pharmacol ; 1990 Jul; 34(3): 187-90
Artigo em Inglês | IMSEAR | ID: sea-107816

RESUMO

Melanin concentrating hormone (MCH: 5 x 10(-12)-5 x 10(-8) M) induced a concentration related, rapid and reversible pigment aggregation in innervated melanophores of Labeo rohita. In inducing melanosome aggregation MCH was found to be 10(4) times more potent than norepinephrine. Experiments employing phentolamine and propranolol suggest that MCH acts through its own specific receptors on the melanophores unrelated to adrenoceptors. MCH was able to aggregate the melanosomes even in the absence of extracellular Ca2+.


Assuntos
Animais , Cálcio/fisiologia , Carpas/fisiologia , Agregação Celular/efeitos dos fármacos , Hormônios Hipotalâmicos , Melaninas/metabolismo , Melanócitos/efeitos dos fármacos , Melanóforos/efeitos dos fármacos , Terminações Nervosas/efeitos dos fármacos , Norepinefrina/farmacologia , Fentolamina/farmacologia , Hormônios Hipofisários/metabolismo , Propranolol/farmacologia , Receptores de Superfície Celular/efeitos dos fármacos , Pele/citologia
16.
Yonsei Medical Journal ; : 357-366, 1988.
Artigo em Inglês | WPRIM | ID: wpr-176788

RESUMO

Though the malignancy of a tumor is generally postulated to be affected by the degree of differentiation of tumor cells, the relationship between differentiation and malignancy of tumors has not been clearly elucidated. Using in vitro established mouse(B16) and human(IGR3) melanoma cell lines, we performed various in vitro and in vivo experiments to clarify the relationship between melanogenicity and malignancy. High and low melanin-producing clones were selected from both cell lines by the limiting dilution technique and their melanogenicities were confirmed by the determination of melanin quantity and tyrosinase activity along with electron microscopic examination. Selected clones from both cell lines revealed that low melanin-producing clones showed a slightly broader chromosomal distribution, a shorter doubling time with a higher DNA synthesis and a greater colony forming capacity in semi-solid agar medium than those of high melanin-producing clones. The low melanin-producing clone derived from B16 also had a lower tumor-take dose and a more rapid tumor-growth rate than the high melanin-producing counterpart following transplantation into syngeneic mice. These results support the concept that the melanogenicity and other biological characteristics associated with malignancy are inversely related in malignant melanoma cells.


Assuntos
Humanos , Camundongos , Animais , Linhagem Celular , Melaninas/metabolismo , Melanoma/patologia , Melanoma Experimental/patologia , Camundongos Endogâmicos , Microscopia Eletrônica , Transplante de Neoplasias , Neoplasias Cutâneas/patologia , Células Tumorais Cultivadas/patologia , Ensaio Tumoral de Célula-Tronco
17.
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