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Biomedical subjects

M C Mihm

Publications and source records attributed to M C Mihm.

At least 235 records · Page 13Linked to original sources
PubMed1981

Microvascular injury in lymphomatoid granulomatosis involving the skin. An ultrastructural study.

An electron microscopic study of a cutaneous lesion of lymphomatoid granulomatosis taken from a patient with pulmonary involvement was performed. Microvascular alterations ranged from mild, degenerative changes to vessel necrosis. Less severe changes included enlarged endothelial cells, with margination of small lymphoid cells in affected vessels. Luminal occlusion by necrotic endothelial cell fragments and fibrin was associated with thickening and reduplication of the basal lamina and an angiocentric, inflammatory infiltrate in severely affected vessels. The most frequently observed cells in the infiltrate were cleaved and noncleaved lymphocytes that exhibited notable cytolysis and degenerative changes in cytoplasmic organelles. We conclude that lymphomatoid granulomatosis involving the skin is a disorder in which substantial numbers of cleaved and noncleaved lymphoid cells participate, eventuating in small-vessel necrosis and occlusion and repeated endothelial cell regeneration.

Aged↗
PubMed1980

Clinical and histological skin changes in chronic renal failure: evidence for a dialysis-resistant, transplant-responsive microangiopathy.

The relation between chronic renal failure and the clinical and histological findings in normal-looking skin was studied in twenty-seven patients with minimum to marked rises of serum creatinine; eleven of these were on maintenance haemodialysis, and three were successful renal transplant recipients. Clinical findings, including pruritus and xerosis which affected 48% and 60%, respectively, of the patients overall, correlated strongly with severity of renal failure. Histological examination revealed endothelial cell activation and/or necrosis, basement membrane zone thickening, and reduplication of the basal lamina involving both venules and arterioles in all specimens. The microangiopathy was severe in 18 of 24 (75%) of the uraemic specimens, but severity correlated poorly with serum creatinine level, haemodialysis status, or known duration of renal failure, except that it was less severe in the first 2 years (p < 0.02). In contrast, the microangiopathy was very much less severe in the transplant recipients than in haemodialysed patients (p < 0.02) and, in the patient studied both before and after transplantation, changes regressed from severe to moderate within 2 months of transplantation. Other histological findings present in many specimens did not correlate with vessel changes. The findings establish the existence of a potentially reversible microangiopathy in normal-looking skin of patients with chronic renal failure. Further study is needed to determine if it reflects the same pathological process that underlies the development of accelerated atherosclerosis responsible for about half the deaths among patients on maintenance haemodialysis.

Adolescent↗
PubMed1980

Clinical characteristics of early cutaneous melanoma.

Clinical characteristics of the primary tumor in 786 patients with superficial spreading melanoma were studied in a prospective sequential series of patients from the Melanoma Clinical Cooperative Group. The most useful features for early diagnosis were change in size and change in color, present in 71% and 55% respectively of patients with level II lesions. Increase in height of lesion correlated with more advanced disease. Ulceration and bleeding were predominantly found in advanced primary lesions and are consequently of limited use in early recognition. Awareness of the historical and clinical features of the primary tumor should result in early recognition and cure of most primary superficial spreading melanomas.

Adult↗
PubMed1980

The specificity and clinical usefulness of the lupus band test.

Granular deposition of immunoglobulin at the dermoepidermal junction is characteristic, but not pathognomonic, of lupus erythematosus. When rigid criteria for the lumpus band test are used, a positive result is highly specific. A positive band test is found in clinically normal skin and lesional skin of systemic lupus patients, and in lesional skin of discoid lupus patients. A positive band test is found infrequently in clinically normal skin of patients with other connective tissue disorders. Cutaneous lupus may be difficult to separate from other morphologically similar disorders. The lupus band test is useful in differential diagnosis because other disorders have either a specific pattern of immunoglobulin deposition or no immunoglobulin deposition. The mechanisms of immunoglobulin deposition at the epidermal basement membrane zone are discussed as well as pertinent clinical correlations of the positive band test.

Antibodies, Antinuclear↗
PubMed1980

Primary melanoma of the skin: recognition and management.

Primary melanoma of the skin, once a rare tumor, has been increasing so rapidly in the past few decades that melanoma now has a higher incidence than Hodgkin's disease. The early diagnosis and surgical treatment of melanoma are the only approach to date that has increased survival--chemotherapy, immunotherapy, and radiation therapy provide little or no benefit. Therefore, all physicians need to be on the alert for early melanoma. This guide is intended to provide the physician both with the tools to diagnose cutaneous melanoma and a suggested approach to its management. It is hoped that as this type of information becomes more widely disseminated, a continued improvement in early recognition and survival will be effected.

Biopsy↗
PubMed1980

Melanoma. An ultrastructural study of the host inflammatory and vascular responses.

Electron microscopic studies of 4 surgically excised human primary superficial spreading melanomas of the skin were done with special emphasis on the host inflammatory and vascular responses to tumor. Host cells participating in the inflammatory response included numerous small lymphocytes, activated macrophages, and mast cells. Some mast cells had lost local portions of granule content, but complete degranulation of mast cells was not seen. Activated macrophages had avidly ingested melanin granules and cellular debris and often were close to dying tumor cells. Lymphocytes, many displaying motile forms, were actively invading the epidermis; formed perivascular cuffs around damaged vessels; and were in intimate contact with living, damaged, and dead melanoma cells. Basophils, eosinophils, and neutrophils were absent from inflammatory infiltrates. Changes of the microvasculature included focal endothelial necrosis and hypertrophy as well as basal lamina changes indicative of repeated episodes of endothelial injury, necrosis and regeneration. These findings are discussed in relationship to a number of recent studies of the immunologically-mediated inflammatory responses to contact allergy, graft rejection, and syngeneic tumor rejection, in man and animals.

Blood Vessels↗
PubMed1980

The microvasculature is the critical target of the immune response in vascularized skin allograft rejection.

Vascularized first set human skin allografts were rejected largely by a process of extensive and progressive microvascular damage leading to ischemia and infarction. Microvascular injury was associated with a cellular immune response. However, vessel damage was at least in part immunologically nonspecific because vessels of the graft bed (host tissue) were damaged as well as those of the graft itself. We conclude that the microvascular endothelium is the critical target of the immune response in vacularized skin allografts in man, and that this sequence of events--primary vascular damage followed by ischemic infarction--may have significance in a variety of experimental and clinical settings.

Adult↗
PubMed1980

Oral warty dyskeratoma.

An elderly woman had a small verrucose hyperkeratotic papule on the hard palate. Histologic examination showed the lesion to be a warty dyskeratoma. Warty dyskeratoma may represent an abnormal keratinization response to intraoral trauma or inflammation. All eight previously reported cases are reviewed. Clinically, the lesions appeared as verrucose hyperkeratotic papules or as focal mucosal depressions, sometimes filled with keratin. Eight of nine lesions were located on the hard palate or on an alveolar ridge.

Aged↗
PubMed1979

Early recognition of cutaneous melanoma.

Criteria for the early recognition of malignant melanoma include appreciation of variegation in color and irregularity of lesion border and pigment pattern. Application of these criteria should result in the diagnosis of cutaneous melanoma in its premetastatic surgically curable phase.

Adult↗
PubMed1979

Rejection of first-set skin allografts in man. the microvasculature is the critical target of the immune response.

Recent reports of microvascular injury in delayed hypersensitivity skin reactions prompted us to reexamine the pathogenesis of first-set skin allograft rejection in man using morphologic techniques that allowed both extensive vessel sampling and unequivocal evaluation of microvascular endothelium. We here report that widespread microvascular damage is a characteristic, early consequence of the cellular immune response to first-set human skin allografts and is qualitatively similar to, but substantially more extensive than, that occurring in delayed hypersensitivity reactions. Microvascular damage in invariably preceded significant epithelial necrosis and affected initially and primarily those venules, arterioles, and small veins enveloped by lymphocytes. Vessels of both the allograft itself and the underlying graft bed (recipient tissue) were equally affected. These data suggest that endothelial cells of the microvasculature are the critical target of the immune response in first-set vascularized skin allograft rejection in man and that rejection can be attributed largely to ischemic infarction resulting from extensive microvascular damage. Other mechanisms, such as direct cellular contacts between infiltrating lymphocytes and epithelium, apparently played only a minor role. The findings presented here indicate that the rejection of first-set vascularized skin allografts, though induced by immunologically specific mechanisms, is primarily effected by final pathways that are relatively nonspecific and that may cause damage to both foreign and host vessels and cells. Rather than contradicting studies demonstrating the exquisite specificity of allograft rejection in other systems, these findings provide a further example of the heterogeneity of the cellular immune response. Recognition of the critical role of immunologically mediated microvascular injury may prove important both for an understanding of the biology of allograft rejection and for strategies aimed at prolonging allograft survival.

Antibody Formation↗
PubMed1979

On the prognostic importance of white depressed areas in the primary lesion of superficial spreading melanoma.

The lesions of 163 patients with superficial spreading melanoma (SSM) were examined for the presence of white, depressed areas; and lesions with and without these areas of "regression" were compared. There was no statistically significant correlation with the histological level of invasion (Clark-Mihm), sex or age of the patient, location of the melanoma, or presence of local, intransit or regional lymph node metastases. It is apparent from examining the recurrence rate and patient survival, that white depressed areas in an SSM are not of prognostic importance. There was a striking correlation of the presence of white depressed areas with the size of the area covered by the malignant melanoma (p less than or equal to 0.001).

Adult↗
PubMed1979

Cutaneous necrotizing venulitis in patients with cystic fibrosis.

Palpable purpura was noted to occur late in the course of some patients with cystic fibrosis. Skin biopsy specimens showed necrotizing venulitis characterized by a perivenular infiltrate composed of neutrophilic leukocytes, fibrin, hypogranulated mast cells, and endothelial cell necrosis. Circulating immune complexes were detected. Recurrent pulmonary infections and the chronic administration of therapeutic agents provide sources of potential antigens.

Adolescent↗
PubMed1979

Birthmarks with serious medical significance: nevocullular nevi, sebaceous nevi, and multiple café au lait spots.

Birthmarks of potential medical significance were identified among 4,641 newborn infants: 1.1% had a nevocellular nevus and 0.3% had a sebaceous nevus; 1.8% of black infants, but no white infants, had three or more café au lait spots. The large nevocellular nevus is considered premalignant, but the significance of the small nevocellular nevus has not been established. The sebaceous nevus fades after birth but undergoes hyperplasia at puberty. Multiple café au lait spots occur less commonly in white than in black infants, and are therefore of greater concern as possibly an early sign of neurofibromatosis.

Child, Preschool↗
PubMed1979

Histological changes produced in skin by equally erythemogenic doses of UV-A, UV-B, UV-C and UV-A with psoralens.

The sequential light microscopic histological changes produced in human skin by a single exposure of UV-A, UV-B, UV-C and oral 8-methoxypsoralen plus UV-A (PUVA) causing approximately equal degress of delayed erythema response, have been evaluated. UV-C and UV-B affect the epidermis to a greater degree than UV-A, while UV-A affects the dermis to a greater degree than UV-B and UV-C. PUVA has prominent effects on both epidermis and dermis, differing in degree from those changes induced by UV-A, UV-B, and UV-C and are longer lasting. The sequence of histological changes following UV exposure is completed more rapidly after exposure to shorter UV wavelengths.

Adult↗