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Biomedical subjects

H Kamino

Publications and source records attributed to H Kamino.

At least 37 records · Page 2Linked to original sources

Differential expression of the H-ras mutated and normal alleles in rabbit DMBA-induced keratoacanthomas.

Keratoacanthomas (KAs) are benign and self-regressing tumors in which a high incidence of the mutated H-ras oncogene has been observed both in humans and in experimental models. To determine the level of expression of the mutated H-ras allele with respect to its normal counterpart in 7,12-dimethylbenz(a)anthracene (DMBA)-induced KAs in rabbit skin, we have utilized a quantitative technique based on reverse transcription polymerase chain reaction (RT-PCR) and selective cleavage of the mutated molecules of the H-ras gene. Analysis of 16 KAs showed that the mutated H-ras transcripts were up to 3-fold more abundant than the non-mutated H-ras transcript in the different tumors. This higher expression of the mutated allele appears to correlate with increased differentiation in the KAs and in turn may contribute to tumor regression.

9,10-Dimethyl-1,2-benzanthracene↗

Lymphoepithelioma-like carcinoma of the skin treated with Mohs micrographic surgery in combination with immune staining for cytokeratins.

Lymphoepithelioma-like carcinoma of the skin (LLCS) is a rare cutaneous neoplasm that histologically resembles nasopharyngeal lymphoepithelioma. Conventional surgical excision carries a considerable rate of recurrence (three of 11 reported cases with such treatment, with one patient dying of metastatic disease). We report the first case of lymphoepithelioma-like carcinoma of the skin treated with Mohs micrographic surgery. Because of its tendency to occur on the face and its potential for recurrence after incomplete removal, this tumor is a good candidate for treatment with Mohs micrographic surgery. Immunohistochemical staining of frozen sections for cytokeratins may help to detect neoplastic cells that may be obscured by the dense lymphoplasmacytic infiltrate associated with this tumor.

Aged↗

Neutrophil-rich, Ki-1-positive anaplastic large-cell malignant lymphoma.

The presence of neutrophils, in the absence of necrosis, is uncommon in malignant lymphoma (ML). We identified a subgroup of Ki-1-positive anaplastic large cell ML (Ki-1 ALCL) in which neutrophils were a prominent component. Six of 20 cases of Ki-1 ALCL had a significant neutrophil infiltrate that varied from 5 to 10% to > 50% of cells per high power field. Neutrophils were not seen in 100 cases of other types of ML reviewed. Patients were first seen with skin lesions (four), localized lymphadenopathy (three), generalized lymphadenopathy (one), and localized extranodal disease (one). All had primary disease. Two patients had peripheral neutrophilia. Three of six patients had clinical stage IV disease. Four patients are currently in clinical remission; one died of recurrent disease; and one patient with acquired immunodeficiency syndrome (AIDS) died of Pneumocystis carinii pneumonia. Four cases demonstrated a T-cell phenotype, one of which arose in a patient with AIDS. Two had a B-cell phenotype. All cases were positive for CD30 (Ki-1). These observations expand the morphologic spectrum of Ki-1 ALCL to include a neutrophil-rich variant. We conclude that the presence of neutrophils is another morphologic feature shared by some cases of Ki-1 ALCL, lymphomatoid papulosis, and Hodgkin's disease, which suggests a possible pathogenetic link among them.

Adult↗

AIDS-associated Kaposi's sarcoma in Romanian children.

BACKGROUND: Kaposi's sarcoma (KS) is commonly associated with the acquired immunodeficiency syndrome (AIDS) in adults. Little is known regarding its occurrence in children. OBJECTIVE: Our purpose was to report the clinical and epidemiologic characteristics of KS in three Romanian children with AIDS and to compare them with previously reported AIDS-associated KS in children. METHODS: This was a clinicopathologic study and computer-based literature review. RESULTS: All three Romanian children had skin involvement; two had involvement of lymph nodes and internal organs. All had acquired human immunodeficiency virus (HIV) infection postnatally. Including these children, 33 cases of AIDS-associated KS in children have been reported. Thirteen of 30 evaluable patients had acquired HIV infection postnatally; nine of these children (69%) had cutaneous involvement by KS. A perinatal route of transmission was present in the remaining 17 cases; only two of these children (12%) with KS had cutaneous involvement. No case was noted in which intravenous drug use was the sole parental HIV risk factor. CONCLUSION: The data support the contention that KS is caused by a second infectious agent prevalent only in certain HIV-infected populations. Children of parents in high-risk groups for KS and children who acquire HIV via contaminated blood or blood products are at highest risk for KS. The route of acquisition of HIV infection may also be associated with different clinical manifestations of KS in children.

Acquired Immunodeficiency Syndrome↗

Acquired cutaneous smooth muscle hamartoma.

A 35-year-old white man had an indurated, indistinct plaque on the anterior aspect of the neck for 10 years. Results of biopsy specimens showed an excess of smooth muscle bundles scattered throughout the dermis. Unlike previously reported cases of acquired smooth muscle hamartomas, it did not occur in association with a Becker nevus.

Adult↗

Neonatal pemphigus vulgaris in a child born to a woman in remission.

We describe the tenth reported case of neonatal pemphigus that mimicked Bart's syndrome and review previously published cases. Unlike previous cases, the child was born with significant blistering to a mother who was in complete remission throughout the pregnancy. High antepartum maternal titers of anti-intercellular space antibodies, increased maternal disease activity, and maternal disease that requires high doses of corticosteroids or use of combined therapy correlate with poor fetal outcome, including intrauterine death.

Adult↗

Eruptive pseudoangiomatosis: a unique childhood exanthem?

We describe three children with an acute onset and spontaneous resolution of angioma-like papules during an apparent viral illness. A biopsy specimen from one patient revealed a unique histologic appearance that consisted of dilated dermal blood vessels with plump hobnail-shaped endothelial cells. On the basis of the natural history and histopathologic features of this exanthem, we suggest the name eruptive pseudoangiomatosis.

Angiomatosis↗

Bacillary angiomatosis in a child undergoing chemotherapy.

Bacillary angiomatosis is an infectious disease of the skin and viscera characterized by vascular lesions, originally described in patients with human immunodeficiency virus infection. There are also case reports of bacillary angiomatosis occurring in immunocompetent patients and in noninfected patients with suppressed immune function. We report a case of bacillary angiomatosis in a child undergoing chemotherapy for acute leukemia.

Angiomatosis, Bacillary↗

Multiple subcutaneous leiomyosarcomas in an adolescent with AIDS.

The case of 17-year-old boy with thalassemia major who contracted the human immunodeficiency virus (HIV) through multiple transfusions is described. Eight years after the onset of generalized lymphadenopathy, and 5 years after the documentation of HIV infection on serologic grounds, he developed the first of multiple, painful, subcutaneous nodules, which proved to be leiomyosarcomas of vascular origin. The histopathology and possible pathogenesis of these unusual tumors are discussed.

Acquired Immunodeficiency Syndrome↗

Painful, plaque-like, pitted keratolysis occurring in childhood.

Pitted keratolysis is a superficial infection of the soles of the feet that is almost always asymptomatic. A painful variant of this disorder was reported to occur in adult males during military service. We report painful, plaque-like, pitted keratolysis in two children. Treatment with topical erythromycin was curative.

Adolescent↗

Dermatomyofibroma. A benign cutaneous, plaque-like proliferation of fibroblasts and myofibroblasts in young adults.

We report nine examples of a distinct cutaneous plaque-like proliferation of fibroblasts and myofibroblasts. Eight of nine lesions were located in or around the shoulder, including axilla and upper arm. There was a predominance of women to men of 8:1. The lesions measured from 1 to 2 cm in greatest diameter. All patients were young adults (mean age 29.8 yr). All lesions involved the reticular dermis in a plaque-like fashion and extended to the upper part of the subcutaneous septa in seven cases. The lesions consisted of a proliferation of very uniform slender spindle-shaped cells arranged as well-defined elongated and intersecting fascicles with a predominantly parallel arrangement to the skin surface. There was no evidence of cytologic atypia and mitotic figures were infrequent. The spindle-shaped cells were separated by thin collagen fibers. Elastic fibers were preserved and some of them appeared thicker than normal. All adnexal structures were spared. Immunohistochemistry revealed that the cells stained positively for vimentin and muscle actin, but lacked smooth-muscle specific actin, desmin, and S-100 protein. Some dermal dendrocytes stained positively for Factor XIIIa, but the spindle-shaped cells were negative. Electron microscopy studies revealed a mixture of fibroblasts, myofibroblasts, and undifferentiated mesenchymal cells. All lesions were treated by conservative excision; follow-up information revealed no evidence of recurrence. We name this distinct lesion dermatomyofibroma. To the best of our knowledge, this entity has not been previously described in the literature.

Adult↗

Unusual benign fibrous and fibrohistiocytic tumors of the skin.

This article reviews recently reported unusual benign fibrous and fibrohistiocytic tumors of the skin. Some of these lesions are variants of common and well-known entities. Because some of these variants have cytologic atypia, they could be confused with malignant neoplasms.

Fibroma↗

Immunoperoxidase technique modified by counterstain with azure B as a diagnostic aid in evaluating heavily pigmented melanocytic neoplasms.

Heavily-pigmented melanocytic neoplasms are difficult to evaluate on routine hematoxylin and eosin stained slides because pigmented melanocytes are difficult to distinguish from the numerous melanophages that are usually seen in the background of these lesions. Immunoperoxidase staining for S100 protein or HMB-45 antibody using diaminobenzidine (DAB) as chromogen, which forms a brown product, does not adequately distinguish melanocytes from melanophages. We modified this technique by replacing hematoxylin as the counterstain with azure B, which stains melanin green-blue. Thus, positive melanocytes appear brown while melanin granules in their cytoplasm are green-blue. However, negative melanophages only stain green-blue. This technique is useful in evaluating heavily pigmented melanocytic lesions such as malignant melanomas, melanosis of regressing malignant melanoma, residual malignant melanoma in areas of granulation tissue with melanophages, blue nevi, pigmented spindle cell variant of Spitz's nevi and combined nevi.

Azure Stains↗

ras activation in human tumors and in animal model systems.

Environmental agents such as radiation and chemicals are known to cause genetic damage. Alterations in a limited set of cellular genes called proto-oncogenes lead to unregulated proliferation and differentiation. We have studied the role of the ras gene family in carcinogenesis using two different animal models. In one case, thymic lymphomas were induced in mice by either gamma or neutron radiation, and in the other, keratoacanthomas were induced in rabbit skin with dimethylbezanthracene. Human keratoacanthomas similar to the ones induced in rabbits were also analyzed. We found that different types of radiation such as gamma rays and neutrons, induced different point mutations in ras genes. A novel K-ras mutation in codon 146 has been found in thymic lymphomas induced by neutrons. Keratoacanthomas induced in rabbit skin by dimethylbenzanthracene show a high frequency of H-ras-activated genes carrying a mutation in codon 61. The same is observed in human keratoacanthomas, although mutations are in both the 12th and the 61st codons of the H-ras gene. H-ras activation is less frequent in human squamous cell carcinomas than in keratoacanthomas, suggesting that ras genes could play a role in vivo in differentiation as well as in proliferation.

3T3 Cells↗