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Biomedical subjects

G Rowden

Publications and source records attributed to G Rowden.

At least 73 records · Page 4Linked to original sources
PubMed1981

Langerhans cells in dermoid cysts: transmission electron microscopic, cytochemical and immunofluorescent observations.

Langerhans cells were detected in squamous, stratified epithelia lining human dermoid cysts. Their presence was assayed by ATPase staining and reactivity with heteroantisera against "Ia-like" antigens. Transmission electron microscopic studies demonstrated variations in the numbers of cells showing Birbeck granules in epithelia with different degrees of keratinization. Indeterminate cells (i.e. lacking granules), were more frequent in epithelia showing combined mucous and keratinizing differentiation. Membrane-coating-granules and keratohyalin granules were present in epithelia containing Langerhans cells with clearly identifiable Birbeck granules. Interepithelial mast cells were observed in epithelia with mucous differentiation. A relationship between Langerhans cells and keratinization was suggested. Such non-immune functions are compatible with the known macrophage characteristics of the cell.

Adenosine Triphosphatases↗
PubMed1981

Langerhans cells in the normal conjunctiva and peripheral cornea of selected species.

The distribution of Langerhans cells (LCs) in human corneal and conjunctival epithelial sheets was investigated by histochemical, immunofluorescence, and immuno-electron microscopic methods. The LCs stained positive with ATPase and with antibodies to HLA-DR antigen and were negative to DOPA-oxidase. Human conjunctiva showed 250 to 300 LCs/mm2 compared to 15 to 20/mm2 in the peripheral third of the corneal epithelium, approximately similar of LCs were present in Lewis rat, fewer cells in guinea pigs and mice, and no detectable cells in the chick.

Animals↗
PubMed1981

The Langerhans cell.

In all mammalian species so far examined, Langerhans cells or their precursors are the only epidermal cells expressing Ia antigens or their equivalents. In man, xeno-antisera raised in rabbits against purified B-lymphocyte cell membrane antigens were utilized to stain the Langerhans cells by either fluorescent or immunoferritin methods. As high proportion of the indeterminate cells in the epidermis also expressed HLA-DR antigens, and a relationship to Langerhans cells is suggested. Confirmation of these results was obtained in mouse. Alloantisera raised against I-A and I-EC subregion products again stained only Langerhans cells. Fluorescent, immunoperoxidase, and immunoferritin methods were used and confirmation of the specificity of the reaction was achieved at the electron microscope level. Langerhans cells were shown by ATPase staining to be absent from the epithelium of the central cornea, but present in the limbus. Population of the entire corneal epithelium surface was induced by application of irritants or contact sensitizing agents such as DNCB. Grafting of corneas either deficient or populated with Langerhans cells, to skin beds, may answer the question of the influence of such cells on allograft rejection.

Animals↗
PubMed1980

Familial erythrophagocytic lymphohistiocytosis: treatment with vinblastine-loaded platelets.

Identical twin Caucasian boys, age 3 months, were seen with fever of unknown origin, hepatosplenomegaly, and pancytopenia. The diagnosis of familial erythrophagocytic lymphohistiocytosis (FEL) was suspected after examination of Twin A's bone marrow and confirmed by an open liver biopsy of Twin B. Twin A died shortly after diagnosis despite treatment with vincristine and prednisone. At autopsy, the diagnosis was confirmed. Twin B responded initially to a three-week course of weekly vincristine and daily prednisone, but symptoms soon recurred. In an effort to enhance delivery of chemotherapy to the active macrophage target, platelets were loaded with vinblastine and then administered intravenously to th patient every 7-10 days. There was an encouraging response reflected by the disappearance of symptoms and the return of peripheral blood count to the normal range, although increased number of histiocytes was still demonstrable in his bone marrow. After nine weeks, he lapsed completely and became refractory to treatment. He died of pseudomonas sepsis four months after diagnosis. This is the first known attempt to deliver a chemotherapeutic agent directly to the macrophages in treating this disease and represents an interesting concept that merits further exploration.

Biopsy↗
PubMed1980

Granular cell tumor: a clinicopathologic study of 110 patients.

The clinicopathologic features of 118 granular cell tumors (GCT) encountered at two affiliated hospitals were reviewed. A total of 110 patients were affected over this 32-year period of study (71 men, 39 women), and in 5% GCT were multiple. Patients ranged in age from 16 to 58 years (average 32 years) and were symptomatic for an average duration of 11 months prior to diagnosis. There was a greater than expected frequency of GCT among black patients (29%). Although tongue was the single most common anatomic site involved, relatively more GCT (44%) occurred in skin or subcutaneous tissue. Less common locations were breast parenchyma (10 cases), rectal mucosa and anus (6), vulva (4), esophagus and larynx (2 cases each). The correct preoperative diagnosis of this protean tumor was made in only three patients. GCT were surgically treated with the average diameter of resected tumor being 1.2 cm (range 0.2--3.5 cm). Pseudoepitheliomatous hyperplasia was noted in 11 tumors and in one vulvar GCT there was overlying in situ squamous cell carcinoma. Tumors were incompletely excised in 24 of 56 patients having adequate followup; only five of these 24 patients experienced a local recurrence of tumor. Malignant behavior was not observed. Results of histochemical and ultrastructural study are briefly discussed. The precise histogenesis of GCT is uncertain but Schwann cell origin is favored in most cases.

Adenofibroma↗
PubMed1980

Expression of Ia antigens on Langerhans cells in mice, guinea pigs, and man.

In all mammalian species so far examined, Langerhans cells or their precursors are the only epidermal cells expressing Ia antigens or their equivalents. In man, xenoantisera raised in rabbits against purified B lymphocyte cell membrane antigens were utilized to stain the Langerhans cells, by either fluorescence or immunoferritin methods. A high proportion of the indeterminate cells in the epidermis also expressed HLA-DR antigens, and a relationship to Langerhans cells is suggested. Confirmation of these results was obtained in mouse. Alloantisera raised against I-A and I-EC subregion products again stained only Langerhans cells. Fluorescence, immunoperoxidase, and immunoferritin methods were used, and confirmation of the specificity of the reaction was achieved at the electron microscope level. Langerhans cells were shown, by ATPase staining, to be absent from the epithelium of the central cornea, but were present in the limbus. Population of the entire corneal epithelium surface was induced by application or irritants or contact sensitizing agents such as dinitrochlorobenzene. Grafting of corneas either deficient or populated with Langerhans cells, to skin beds, may answer the question of the influence of such cells on allograft rejection.

Animals↗
PubMed1980

Malignant melanoma with melanosis. Ultrastructural and histological studies.

Ultrastructural and histological investigations were performed on a case of generalized melanosis associated with superficial spreading melanoma. The hyperpigmentation of the general body surface, mucous membranes and nail beds was associated with deposition of melanin in macrophages in the dermis, together with some hyperactivity of epidermal melanocytes. Melanin granules were observed lying free in the stroma, suggesting pigment incontinence and phagocytosis by macrophages. Giant melanosomes were noted in melanocytes, keratinocytes and melanophages in the hyperpigmented skin. No evidence was found to suggest dissemination of individual malignant cells throughout the skin. Subcutaneous nodules of malignant melanoma were, however, present, as well as metastases to the iris, liver and to other organs.

Humans↗
PubMed1980

Intrathoracic paravertebral malignant paraganglioma.

This article reviews the clinical and pathologic features of intrathoracic paravertebral paragangliomas. Including the present case, there have been 31 tumors reported in the English literature; the average age of patients was 29 years, with a sex distribution of 20 men and 11 women. Fifteen patients (48%) had symptoms related to excess secretion of catecholamines; the remaining 16 tumors were clinically nonfunctional. Seven patients (22%) had multiple paragangliomas. Complete surgical resection was attempted in 25 patients, 13 were alive with no evidence of tumor an average of 2.2 years later. Tumor was locally invasive in five patients, with involvement of the vertebral canal and symptoms of spinal cord compression. Malignant behavior with distant metastases was observed in two patients. As shown by the present case, the Grimelius stain is a useful diagnostic technique for demonstrating cytoplasmic argyrophilia of neoplastic chief cells. Electron microscopy demonstrated neurosecretory granules (average core diameter, 100 nm). "Light" and "dark" chief cell types were inconspicuous. Due to important clinical and pathologic differences, paravertebral paragangliomas should be distinguished from similar tumors occurring in the anterosuperior mediastinum (aorticopulmonary paragangliomas).

Adult↗
PubMed1979

Unilateral megalencephaly, cerebral cortical dysplasia, neuronal hypertrophy, and heterotopia: cytomorphometric, fluorometric cytochemical, and biochemical analyses.

A 13-month-old boy with intractable seizures, left hemiparesis, and psychomotor retardation due to right unilateral megalencephaly, died in hypovolemic shock 1 day after hemispherectomy. The gyral pattern of the hypermegalic hemisphere was simplified and coarse. The cortical cytoarchitecture was disarrayed by a population of giant neurons. Hippocampus and calcarine cortex were cytoarchitectonically normal, as was the entire left cerebral hemisphere. Neuronal heterotopias were present in the right centrum semiovale and both cerebellar hemispheres. Cytomorphometric study of parietal cortex of each cerebral hemisphere revealed a 4-fold increase in neuronal nuclear, and 11-fold increase in neuronal nucleolar, volume in the hypermegalic hemisphere, whereas glial nuclear volume was only one-third as great, in part because of edema of the left hemisphere. Microfluorometric cytochemical analysis demonstrated a 16% increase in neuronal DNA, 40% increase in total neuronal RNA, 12% increase in glial DNA, and 15% increase in glial RNA on the right. Biochemical analysis of tissue extracts disclosed increases in the right hemisphere of 40%, 56%, and 66%, respectively, for DNA, RNA, and protein. The data suggest heteroploidy of chromosomal DNA and enhanced transcription and translation in the hypermegalic hemisphere. Thus, a defect in regulation of cell metabolism may account for the morphologic and clinical abnormalities.

Brain↗
PubMed1979

Laryngeal paraganglioma. Case report with ultrastructural analysis and literature review.

Laryngeal paraganglioma is an infrequently reported tumor; only 16 examples have been recorded in the English literature. All but one laryngeal paraganglioma originated superiorly in the larynx; involvement of the ipsilateral aryepiglottic fold is common. Male patients predominate (11:5). The average age of patients at the time of diagnosis was 47 years, and symptoms had been present for an average duration of 5.8 years (range 6 months to 27 years). Attempted biopsy has resulted in significant hemorrhage in three cases. As illustrated by the present case, the Grimelius argyrophil stain is a useful diagnostic procedure. Electron microscopy confirmed the presence of neurosecretory granules with core diameters ranging from 110 to 140 nm. Surgical resection is the preferred treatment and has been possible in 14 cases; nine patients are alive and free of tumor for an average of 3 years. Compared to other head and neck paragangliomas, these have a more malignant course with a 25% mortality; tender subcutaneous metastases are commonly observed in these patients.

Adult↗
PubMed1979

Ia antigens on indeterminate cells of the epidermis: immunoelectronmicroscopic studies of surface antigens.

An antiserum against human B-lymphoblastoid cell membrane alloantigens (Ia-like antigens) was used to study the presence of such antigens on dendritic cells in human epidermis. Only Langerhans cells and the majority (85%) of so-called indeterminate cells were positively stained, as shown by immuno-electron microscopy. Fifteen percent of the indeterminate cells were negative and were considered to be immature melanocytes. A relationship exists between the indeterminate cell and the Langerhans cell. A proposal is made concerning emigration of Langerhans cells in response to haptenic stimulation, and the immigration of indeterminate cells to restore the status quo.

Antigens, Surface↗
PubMed1979

Target role of Langerhans cells in mycosis fungoides: transmission and immuno-electron microscopic studies.

Langerhans cells of the epidermis are "special" macrophages, as indicated by their expression of Fc and C3 receptors and Ia antigen. Functionally, they can replace macrophages in presentation of antigens to T cells and in the MLR. Ultrastructural and immunologic studies were carried out on epidermal samples of mycosis fungoides. As in contact allergy, apposition of lymphocytes to Langerhans cells was noted. Destruction of Langerhans cells appeared to act as the focus for the development of Pautrier microabscesses. This destruction was accompanied by ingress of histocytic cells, probably related to the stem cell population for Langerhans cells. The target cell role of Langerhans cells appears to be similar in contact allergy and mycosis fungoides.

Antigens↗
PubMed1978

Small lymphocyte T-cell leukemia in the adult.

A 49-year-old man is described with morphologic T cell chronic lymphocytic leukemia, whose clinical course, however, progressively deteriorated with central nervous system involvement, resistance to treatment and death within eight months. In addition to widespread organ invasion by leukemic cells there was depression of cellular immunity. The leukemic lymphocytes showed an aberrant response to mitogens, and despite undetectable Ia-like surface antigens were able to stimulate allogeneic cells in the mixed leucocyte reaction. From this and similar cases reviewed herein, it appears that the syndrome of small T-lymphocyte leukemia of the adult is a rapidly aggressive and resistant disease with characteristic clinical and laboratory findings.

Humans↗
PubMed1978

Immunologic changes in regional lymph nodes of melanoma patients.

In tumor-draining lymph nodes, humoral immunity is diverted from individually specific, cytotoxic anti-membrane AB to less specific anti-cytoplasmic AB with progression of the disease. Auto-anti-anti-bodies and suppressor cells seem to be involved in the failure of control of metastasis.

Antibodies, Neoplasm↗
PubMed1978

Melanoacanthoma. Ultrastructural and immunological studies.

Electronmicroscopic studies confirmed that melanoacanthoma is a non-nevoid elevated epithelial tumor composed of keratinocytes of both basaloid and spinous differentiation and of large dentritic melanocytes. The block in transfer of pigment from melanocytes to keratinocytes was found not to be complete. Langerhans cells, present in the malpighian layers were normal in morphology. Immunofluorescent studies and an immunoprecipitin assay also showed our patient's melanoacanthoma not to be related to malignant melanoma.

Aged↗