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Biomedical subjects

J E Muhlbauer

Publications and source records attributed to J E Muhlbauer.

At least 19 recordsLinked to original sources
PubMed1992

Bubble hair.

An unusual hair dystrophy was studied by means of light and electron microscopy. Hair fibers demonstrated a boomerang deformity containing small and large "bubbles". Electron microscopy revealed a loss of cortical cells and medulla at these sites. Cross-section images showed either a single large cavity or a reticulated, "swiss cheese-like" loss of cells. These two cases represent the second and third reported cases of bubble hair deformity. We present the second light and electron microscopic study of this disorder, including new electron microscopic findings. The cause of bubble hair deformity remains obscure. The involved tufts of wiry hair resolved with gentle hair care. This suggests that trauma to the hair shaft may play a role. It is likely that additional cases of bubble hair remain unrecognized. Investigation of other patients with localized tufts of wiry hair is likely to reveal additional cases.

Adult↗
PubMed1991

Studies on the cellular origin of neurothekeoma: clinical, light microscopic, immunohistochemical, and ultrastructural observations.

The clinical, histopathologic, and immunohistochemical features of 11 cases of neurothekeoma are reported. One case was examined by electron microscopy. The mean age of the patients was 27.1 years; the study comprised eight female and three male patients. Most lesions were nondescript papules and located on the upper part of the body, seven cases of neurothekeoma on the head. Eight cases were classified as cellular neurothekeoma on the basis of a striking fascicular pattern and three cases as myxomatous neurothekeoma because of prominent myxoid stromal change. All cellular neurothekeomas failed to express S-100 protein, whereas the three myxomatous types were strongly positive for this marker. Other than vimentin, there was no significant immunoreactivity with other immunohistochemical markers. Ultrastructural study of one case of cellular neurothekeoma was inconclusive for cell type although a perineurial origin could not be excluded. On the basis of these results, we conclude that cellular neurothekeoma differs from myxomatous neurothekeoma not only by clinical and histologic findings but also by immunoreactivity with S-100 protein. These findings also suggest the existence of two distinct subtypes of neurothekeoma and possible origin of the two variants of neurothekeoma from different cell types or at least variation in phenotypic expression of a common cell type. On the other hand, it cannot be excluded that these two variants are different stages in the natural history of neurothekeoma.

Adolescent↗
PubMed1988

Sporadic dysplastic nevus syndrome in a tyrosinase-positive oculocutaneous albino.

A case of dysplastic nevus syndrome in a 41-year-old tyrosinase-positive oculocutaneous albino man is presented. Clinically the patient exhibited multiple amelanotic lesions; histologic examination provided the diagnosis of dysplastic nevus syndrome. Fontana-Masson silver staining revealed the presence of melanin in the nevus cells. Hair bulbs incubated in tyrosine buffer produced melanin. This is the second reported case of dysplastic nevus syndrome in an oculocutaneous albino and the first case of dysplastic nevus syndrome in a tyrosinase-positive albino of which we are aware.

Adult↗
PubMed1986

The spectrum of minimal deviation melanoma: a clinicopathologic study of 21 cases.

A retrospective study of 21 patients with the histopathologic diagnosis of minimal deviation melanoma (MDM; n = 18) and borderline melanoma (BM; n = 3) was undertaken to determine the prognosis for these patients compared with that for patients with other types of malignant melanoma. The findings indicate that the prognosis for these uncommon nevomelanocytic tumors is somewhat better than that for other malignant melanomas. Follow-up periods in this series ranged from 18 to 96 months (mean, 57 months). Primary lesions ranged in thickness from 1.6 to 10.4 mm. The histopathologic subtypes included the Spitz variant (nine patients), the spindle cell variant (six patients), the combined spindle and epithelioid cell type (three patients), and the small epithelioid cell type (three patients). Only two of the patients died of widespread metastatic disease. Comparison of the histologic and clinical prognostic indicators of mortality in patients who have malignant melanoma with the clinical and pathologic features seen in this series of 21 patients would appear to indicate a diminished tendency toward metastatic or recurrent disease in patients with MDM and BM.

Adolescent↗
PubMed1986

Epidermal antigen preservation with freezing.

Antigen preservation in human foreskin was evaluated after prolonged storage. Foreskin sections previously separated and stored were examined after 24 h, 6 days, 102 days, 364 days, and 493 days, using indirect immunofluorescence techniques. Each foreskin was evaluated with high-titer human antisera against bullous pemphigoid and pemphigus antigens, rabbit antiserum against laminin, and IgG murine monoclonal antibodies against OKT6, OKIa, AF-1, and Kab-3. Each section was studied and scored by three independent observers. Except for decreased fluorescent staining of pemphigus antigens, no decrease of the immunofluorescence titers was seen over the period of observation.

Antibodies↗
PubMed1984

Cat-scratch disease. Bacteria in skin at the primary inoculation site.

Cat-scratch disease is a zoonotic infection characterized by a skin papule at the site of the scratch followed by regional lymphadenitis. Recently, small gram-negative pleomorphic bacilli were demonstrated in sections of lymph node from patients with the disease. We now report identical bacteria in the primary inoculation site of three patients with cat-scratch disease. Lymph nodes from two of these patients also contained the same bacilli. Identical bacteria in both skin and lymph nodes from these patients are further evidence that the bacilli are the cause of cat-scratch disease. In early infections, biopsy of the primary site of inoculation and demonstration of bacilli may replace excision and histologic examination of lymph node in establishing the diagnosis of cat-scratch disease.

Adolescent↗
PubMed1984

Immunopathology of pityriasis lichenoides acuta.

Eleven biopsy specimens (five papules and six dusky or crusted lesions) from four patients with pityriasis lichenoides et varioliformis acuta ( PLEVA ) were studied by direct immunofluorescence and immunoperoxidase technics. Slight vascular deposits of IgM and C3 were present in most lesions. Slight perivascular deposits of fibrin were observed in early lesions; more extensive perivascular and interstitial deposits of fibrin were detected in advanced lesions. Most of the infiltrating cells were T lymphocytes; cells with cytotoxic/suppressor phenotype (T8-positive) were generally more numerous than cells with helper/inducer phenotype (Leu-3a-positive, T4-positive). A marked increase in epidermal T8-positive cells over epidermal Leu-3a/T4-positive cells was found in late lesions. Moreover, a reduction of the ratio of circulating T4-positive to T8-positive cells was observed in most cases. The number of epidermal T6-positive (Langerhans/indeterminate) cells was decreased in the lower as compared with the upper stratum spinosum. About 5% of perivascular infiltrating cells were T6-positive. These results suggest that cell-mediated immune mechanisms are probably important in the pathogenesis of PLEVA .

Adult↗
PubMed1984

Pre-Kaposi's sarcoma.

Clinically uninvolved skin in a homosexual patient with acquired immunodeficiency syndrome and Kaposi's sarcoma showed abnormal vascular proliferation (pre-Kaposi's sarcoma). The diagnostic and therapeutic implications of this finding are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Papular polymorphous light eruption. Fibrin, complement, and immunoglobulin deposition.

Biopsy specimens of papules taken from eight patients with polymorphous light eruption ( PMLE ) were examined by a direct immunofluorescence technique. Extensive intervascular and focal perivascular deposits of fibrin were detected in each case. Slight vascular deposition of C3 and IgM were observed in five and two patients, respectively. The lupus band test was negative in all cases. The findings suggest that venular injury with activation of the clotting system is involved in the development of lesions in PMLE .

Adult↗
PubMed1983

Multiple agminated spindle cell nevi: unique clinical presentation and review.

A boy with agminated spindle cell nevi is described. Present within the area of involvement were congenital nevocellular and composite spindle/nevocellular nevi. Other unusual features included a dynamic pattern of growth and regression of the lesions, with the presence of halo nevi and background café au lait pigmentation. This unique presentation of multiple nevi is discussed in the context of previous reports of agminated spindle cell nevi.

Child↗
PubMed1983

T6 is superior to Ia (HLA-DR) as a marker for Langerhans cells and indeterminate cells in normal epidermis: a monoclonal antibody study.

Previous studies in our laboratory using immunoelectron microscopy have shown that anti-T6 monoclonal antibody reacts with all epidermal Langerhans cells in normal skin. Comparison of the number of T6-positive (+) epidermal cells with Ia (HLA-DR) (+) cells, as defined by the monoclonal antibodies, anti-I1 and anti-I2, disclosed that these latter markers significantly underestimated Langerhans cell and indeterminate cell numbers (p less than 0.01 and p less than 0.001, respectively) when employed in a sensitive 4-step immunoperoxidase procedure. Thus, it appears that all epidermal Langerhans cells and indeterminate cells are not Ia-positive as defined in this system and that Ia(+)/T6(+) and Ia(-)/T6(+) subsets exist. These subsets may be analogous to the Ia(+) and IA(-) subsets of macrophages, in which the former are responsible for antigen interaction with T cells.

Adult↗
PubMed1983

Papular polymorphic light eruption: an immunoperoxidase study using monoclonal antibodies.

Biopsy specimens of papules taken from eight patients with polymorphic light eruption were examined by immunoperoxidase techniques employing monoclonal antibodies. In each case, most infiltrating mononuclear cells were T cells. The majority of T cells were T8-positive (cytotoxic/suppressor) in four cases and T4-positive (helper/inducer) in two. In two cases, approximately equal numbers of both T cell subsets were present. In only three cases were rare B cells identified by their reactivity with anti-IgM antibody. MI-positive mononuclear cells (macrophages) represented less than 5% of cells infiltrating the dermis. In five subjects, anti-T6 antibody stained increased numbers of dermal mononuclear cells considered to be Langerhans/indeterminate cells. The pathogenesis of papular polymorphic light eruption may involve injury to upper dermal venules mediated by T cells and Langerhans/indeterminate cells.

Adult↗
PubMed1983

Minimal deviation melanoma: a histologic variant of cutaneous malignant melanoma in its vertical growth phase.

Minimal deviation melanomas are uncommon nevomelanocytic tumors of indeterminate risk that appear as pigmented or nonpigmented skin nodules and are clinically diagnosed as Spitz nevi, hemangiomas, or malignant melanomas. They are characterized histologically by expansile growth in the papillary dermis with reticular dermal infiltration (minimal deviation type) or without reticular dermal invasion (borderline type). The tumors exhibit lesser cytologic atypia in their vertical growth phase (histologic variance) than observed in common forms of melanoma. A retrospective study of outcome in 21 patients with minimal deviation melanoma (mean tumor thickness by Breslow's measurement = 3.6 mm) disclosed recurrent disease in only 3 patients after a mean observation period of 57 months, supporting the impression that these tumors are not as biologically aggressive as common malignant melanomas. The histologic subtypes of minimal deviation melanoma are reviewed along with a discussion of the concept of histologic variance.

Adolescent↗
PubMed1982

Variegate porphyria in New England.

Variegate porphyria (VP) is an autosomal dominant disease characterized in adults by mechanical fragility and blistering of sun-exposed skin or acute visceral and neurological manifestations. The laboratory diagnosis of VP depends on a search for high levels of coproporphyrin and protoporphyrin in the feces. Variegate porphyria has been infrequently diagnosed in the United States. In this study of five New England families with VP, there were nine manifest, six latent, and six questionable cases among 40 individuals studied. This report reviews the diagnostic approach to and treatment of affected individuals and their families.

Acute Disease↗
PubMed1980

Granuloma annulare.

Granuloma annular (GA) is a benign inflammatory skin disease usually localized to the distal extremities, although generalized, perforating, and subcutaneous variants have also been identified. A regular histopathologic feature is the presence of mononuclear cells, often in palisading array, around foci of altered collagen. The clinical and histologic features of each subtype of GA are discussed along with a differential diagnosis. A variety of remedies have been used to treat GA, but efficacy is hard to define in a disease in which spontaneous resolution is usual outcome. GA has not been conclusively linked either to diabetes or solar radiation. Recent data suggest a role for vascular injury or delayed-type hypersensitivity in the pathogenesis, but the cause of GA remains obscure.

Adult↗