Spectrofluorimetric detection of DMBA-induced mouse skin carcinoma.
(17/10127)
An attempt has been made to evaluate the normal and cancer blood samples of 7,12-dimethylbenz(a)anthracene (DMBA)-induced mouse skin carcinoma by spectrofluorimetric method. Analysis of acetone extracts of plasma, erythrocyte and erythrocyte membrane showed an alteration around 630 nm when excited at 400 nm by cancer samples, compared to normal samples. The ratio of fluorescent intensity at 530 nm/630 nm was found to be decreased in erythrocyte and plasma and increased in erythrocyte membrane. These changes are not detectable in both hemolysates. It has been suggested that erythrocytes may be the carriers of fluorophors that accumulate in cancer tissue and may be useful in the diagnosis and treatment of malignancies. (+info)
Malignant basal cell tumor in a Djungarian hamster.
(18/10127)
A malignant basal cell tumor was found in the skin of the abdomen of a female Djungarian hamster of unknown age and weighing 40 g. Histologically, the tumor mass was composed of cells resembling the basal cells of the epidermis, and these cells exhibited solid type proliferation. In the tumor tissue and necrotic foci, horn cysts were observed. Immunohistochemically, cytokeratin was present in the tumor cells and horncysts. By electron microscopic examination, the tumor cells had scanty cell organelles and a few desmozomes. This paper describes a rare malignant basal cell tumor in a Djungarian hamster. (+info)
Spectrum of p53 gene mutations suggests a possible role for ultraviolet radiation in the pathogenesis of advanced cutaneous lymphomas.
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There is evidence that the incidence of primary cutaneous lymphoma, like other forms of non-Hodgkin's lymphoma, is increasing, yet little is known of the pathogenetic events involved in this group of disorders. In this study we examine the frequency and spectrum of P53 gene mutations in a large series of primary cutaneous lymphomas, with particular emphasis on tumor stage mycosis fungoides, as it is in these cases that p53 overexpression has previously been reported. Sixty-six samples from 55 patients with primary cutaneous B cell and T cell lymphomas were analyzed for mutations in exons 5-9 of the P53 gene using polymerase chain reaction/single strand conformational polymorphism, and subsequent cloning and sequencing of genomic DNA. Fourteen separate P53 mutations were identified in blood, skin, and lymph node samples in 13 patients (24%). Twelve of 14 mutations occurred at dipyrimidine sites, eight resulting in C-->T transitions and one in a CC-->TT tandem base transition, a mutation spectrum strikingly similar to that reported in nonmelanoma skin cancer and characteristic of DNA damage caused by ultraviolet B radiation. In the subset of patients with mycosis fungoides, P53 mutations were identified in six of 17 patients with tumor-stage but in none of 12 patients with plaque-stage disease (Fisher's exact test p = 0.027). These data suggest a role for ultraviolet radiation in the pathogenesis of primary cutaneous lymphomas and a possible ultraviolet B-related step in the progression of mycosis fungoides from plaque to tumor-stage disease. (+info)
Selective promoting activity of phorbol myristate acetate in experimental skin carcinogenesis.
(20/10127)
Experiments were undertaken to study the effect of promotion treatment on epidermal tumour induction pattern in precancerous mouse skin. Swiss albino mice were given a single s.c. injection of 0-5 mg 20-methylcholanthrene in the right scapular region. Six weeks later, 1-83 nmol of phorbol myristate acetate (PMA) was applied biweekly on the reactive skin. Histopathology of the induced tumours showed early appearance of squamous cell carcinomas and rhabdomyosarcomas. Fibrosarcoma, the most common tumour type induced on MCA injection alone, was absent. Trichoepithelioma, a benign tumour, was induced in PMA-treated mice. This gives new evidence of the selective action of PMA, enhancing the induction of epithelial and muscle tumours, with concurrent inhibition of fibroblastic tumours. (+info)
A case of a malignant melanoma with late metastases 16 years after the initial surgery.
(21/10127)
We report a case of a pulmonary metastasis 16 years after the initial surgery for a malignant melanoma. The patient was a 58-year-old Japanese man. In 1976, he had a pigmented skin lesion with a diameter of 8 mm on his right third finger. He received an amputation of the finger and a dissection of the right axillary. Histological examinations of the tumor revealed a feature of a malignant melanoma with infiltration of the papillary layers of the dermis, 1.5 mm in thickness. The histological subtype was considered to be an acral lentiginous melanoma with a mixed spindle-epithelioid cell pattern. There was no regional lymph node metastasis. In December 1992, when he was 74-years-old, a round tumor in the left lower lung was discovered by chest radiography. In February 1993, he received a left lower lobectomy of the lung. Histological examination revealed a feature of a malignant melanoma with predominantly epithelioid cells and this was considered to be a metastasis from the initial skin lesion. Five months after the lobectomy, he died from a hemorrhage of a metastatic brain tumor. This case indicated the importance of periodic, life-long follow-up in treating malignant melanomas. (+info)
memA/DRS, a putative mediator of multiprotein complexes, is overexpressed in the metastasizing human melanoma cell lines BLM and MV3.
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memA was isolated by subtractive hybridization in which the mRNA repertoire was compared in a panel of human melanoma cell lines with different metastasizing potential. Expression of memA mRNA is elevated in the highly metastasizing human melanoma cell lines and derived xenografts, as compared with the non-metastasizing ones. In a collection of human tumor cell lines and melanoma metastasis lesions, memA mRNA expression could be detected in the A-431 (epidermoid carcinoma), HT-1080 (fibrosarcoma), JEG-3 and JAR (choriocarcinomas) cell lines and in three out of 11 melanoma metastasis lesions. The distribution of memA mRNA in a collection of healthy human organs is also tissue restricted. Sequence analysis revealed that the MEMA protein is identical with a 160 kDa nuclear 'domain rich in serines' (DRS) protein occurring free in the nucleoplasm and in U2-ribonucleoprotein structures. MEMA is also homologous to pinin, a 140 kDa protein associated with the desmosome-intermediate filament complex, and to a 32 kDa porcine neutrophilic protein that was copurified with components of the NADPH-oxidase enzyme complex. The encoded amino acid sequence predicts that the MEMA protein has three coiled-coil domains, one glycine loop domain, is very hydrophilic and contains regions rich in glutamine/proline, glutamic acid and serine residues. (+info)
Phase II trial of topically applied miltefosine solution in patients with skin-metastasized breast cancer.
(23/10127)
Skin deposits from breast cancer can present serious therapeutic problems, especially when resistant to conventional therapy. Topical application of a cytotoxic drug may represent an attractive new treatment modality devoid of major systemic toxicity. Miltefosine was selected because of its efficacy in breast cancer models. A mixture of alkylated glycerols of various chain lengths and water was used as the pharmaceutical vehicle to dissolve and to further facilitate tissue penetration of miltefosine. In our Institute a phase II study was performed to determine the efficacy and tolerability of topically applied miltefosine in patients with cutaneous metastases from breast cancer. Thirty-three patients in total entered the trial. A 6% miltefosine solution was applied once daily in the first week and twice daily in the following weeks. The planned minimum treatment duration was 8 weeks. We found an overall response rate of 43% for 30 evaluable patients, composed of 23% complete response and 20% partial response. The median response duration was 18 weeks, range 8-68. Toxicity consisted mainly of localized skin reactions, which could be controlled by a paraffin-based skin cream and, where appropriate, by dose modification. No systemic toxicities were observed. We conclude that topical miltefosine is an effective treatment modality in patients with skin metastases from breast cancer. (+info)
Von Hippel's disease in association with von Recklinghausen's neurofibromatosis.
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Ten members of a large family who showed manifestations of either von Hippel-Lindau disease or von Recklinghausen's neurofibromatosis were examined. Three of 10 members were found to have retinal angiomas which had not been present on fundus examination 3 years previously. These angiomas were associated with ocular and systemic signs of neurofibromatosis. These cases show overlapping manifestations of different phakomatoses and provide support for the concept of a common aetiology for these diseases. (+info)