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Biomedical subjects

R Caputo

Publications and source records attributed to R Caputo.

At least 163 records · Page 9Linked to original sources
PubMed1984

Letterer-Siwe disease in an octogenarian.

The case of an 81-year-old woman suffering for about 1 year from a typical form of Letterer-Siwe disease (LSD) is reported. The only important systemic involvement was hepatosplenomegaly. The patient was treated with steroids and vinblastine and then with thymopoietin pentapeptide. This last drug proved useful for decreasing the dose of steroid and thus for checking the appearance of new skin lesions. The ultrastructural investigations, carried out before and after vinblastine, showed the presence in some histiocytosis X cells (HXC) of coated Birbeck granules (BG). Immunoelectron microscopy showed about 90% of HXC to be OKT6+ and the OKT6 labeling of these cells to be similar to that of the Langerhans cells of normal skin. Five percent of OKT6+ cells apparently contained no Langerhans granules.

Age Factors↗
PubMed1984

Unique aspects of a lesion of erythema elevatum diutinum.

A 70-year-old man with erythema elevatum diutinum developed new lesions on his right hand 4 years after initiation of treatment with dapsone. An unusual protruberant appearance of these lesions grossly and a peculiar fibrosing quality histopathologically of one lesion are features that, to our knowledge, have not been reported previously.

Aged↗
PubMed1984

Netherton's syndrome in two adult brothers.

To our knowledge, these are the first cases of almost complete Netherton's syndrome in two adult brothers born of consanguineous parents. The aromatic retinoid, etretinate, although initially worsened the eczematous manifestations, proved to be capable of reducing the primary skin lesions in one patient.

Adult↗
PubMed1983

The avidin-biotin peroxidase complex (ABCPx)/in skin immunoelectron microscopy.

The interaction between avidin and biotin can be exploited in immunoperoxidase techniques in three main way: the labeled avidin-biotin technique (LAB); the bridge avidin-biotin technique (BRAB); the performed avidin-biotin complex (ABCPx). In a comparative study of these three methods and the peroxidase antiperoxidase method using serial dilutions of antinuclear positive serum, the ABCPx method yielded the most intense staining. For this reason, the ABCPx method has been applied in immunoelectron microscopy (IEM) techniques on normal and pathological skin employing monoclonal OKT4, OKT6, OKT8 antibodies to detect target membrane antigens. The authors notes that the ABCPx method allows strong staining both in normal and pathological skin and improves tissue preservation.

Antigens↗
PubMed1983

The morphologic events of blister formation in porphyria cutanea tarda.

In porphyria cutanea tarda (PCT), the submicroscopic event causing the formation of spontaneous blisters is the appearance of membrane-limited vacuoles in the superficial dermis. These vacuoles are apparently formed through cytolysis of dermal cells and swelling of the pseudopodia of the basal cells protruding into the dermis, probably as a consequence of photochemically-induced lysosomal damage. The number and size of these vacuoles progressively increase near the cleavage area of the blisters, where their limiting membranes merge and break, giving rise to the cavity of the blister, which is formed under the basal lamina. The presence of coated vesicles along the limiting membranes as well as inside the vacuoles suggests their involvement in the transport of fluids from the damaged vessels, thus contributing to the progressive volume increase of vacuoles themselves.

Adult↗
PubMed1983

Cutaneous manifestations in renal transplant recipients.

Out of 105 renal transplant recipients 100 had skin lesions: 55% iatrogenic, 74% infectious, 12% precancerous or cancerous and 4% miscellaneous. Many of these lesions were at least in part transient, and steroid-related skin lesions became less frequent as years progressed. The more frequent infections were the fungal ones, followed by viral and bacterial infections with different patterns of onset. All the precancerous lesions appeared late and were almost exclusively represented by actinic keratoses; 2 evolved into squamous cell epitheliomata. 2 patients died due to Kaposi's sarcoma and melanoma. The high incidence of skin cancers in transplanted patients and the rapid evolution of dyskeratoses into spinaliomas warrants close dermatological surveillance.

Adolescent↗
PubMed1982

A freeze-fracture study of the human nail plate.

This study of freeze-fracture replicas of human nail plate fragments demonstrates that keratin filaments have a width of about 100 A. The 'marginal band' is probably formed by a row of particles, 50 A in diameter, arranged along the inner surface of the plasma membrane. These particles are often masked by keratin filaments. In nonjunctional areas, the plasma membranes are devoid of membrane-associated particles. The only type of junction observed is the desmosome. Even though the modes of keratinization are different, the structures of the keratin pattern, of cell membranes, and of the desmosomes are identical in replicas of wholly keratinized nail and human stratum corneum cells. The ultrastructural differences observed appear to be related to the barrier function carried out by the epidermis and by its desquamation process.

Adult↗
PubMed1982

Freeze-fracture replication technique of human skin.

The freeze-fracture replication technique represents one of the most advanced methods for studying the ultrastructure of biological tissues and has given a new dimension to the ultrastructure research. This technique makes it possible to obtain a cast of a fracture surface of frozen preparations. Apart from allowing samples to be examined without being dehydrated, i.e. under conditions very close to those of living state, it has proved especially useful for the analysis of many tissue functions concerned with membrane activity and exchanges between cells and their disturbance in specific disease conditions. Even through good quality replicas had already been obtained back in 1961 (Moor et al. 1961), only after 1970, mainly thanks to the contribution made by Breathnach and his collaborators (Breathnach et al. 1972, Breathnach 1973, Breathnach et al. 1973) was the freeze-fracture replication technique successfully used in the study of the skin, since this tissue had proved especially difficult to process. In this review paper, technical principles will be summarized and the most important findings so far obtained in the study of normal and pathologic skin will be illustrated.

Cell Membrane↗
PubMed1982

Insulin resistance in a child with Acanthosis nigricans type A.

The patient, a female 6 years 4 months old, diagnosed as affected by Acanthosis nigricans and diabetes mellitus was referred to our Clinic for further investigation of her glucose metabolism. She had a typical face with hypertelorism, prognathism, macroglossia and large auricles. The skin was hyperpigmented, verrucous, hyperkeratotic especially in the folds and flexural areas with small papillomatous or nodular growth; diffused hypertrichosis and hypertrophic clitoris were also present. Biochemical and hormonal investigations revealed no major abnormalities apart from glucose metabolism. After an unsuccessful trial with conventional insulin therapy, endovenous continuous insulin infusion was started: even with 32 U/kg/h it was not possible to achieve normoglycemia. Insulin receptors were studied on erythrocytes: 125I-insulin binding (specific) was clearly lower than normal. The concentration of insulin receptors was reduced, while the average affinity profile was normal. The study of erythrocyte insulin receptors has demonstrated that insulin resistance in this patient is due to a decrease in the number of receptors, i.e. Acanthosis nigricans type A.

Acanthosis Nigricans↗
PubMed1982

Congenital self-healing histiocytosis.

In a typical case of congenital self-healing histiocytosis of the Hashimoto-Pritzker type, the results of an ultrastructural examination of a nodule of a 30-day-old patient showed that about 25% of the cells contained unique phagosomes but no regularly laminated bodies. This case of congenital self-healing histiocytosis is an example of concurrent proliferation of two types of histiocytes (one with and one without Langerhans' granules). Since transitional forms were not observed, this finding might indicate the existence of congenital, self-healing forms of histiocytosis X.

Cytoplasm↗
PubMed1981

Generalized eruptive histiocytoma. A clinical, histologic, and ultrastructural study.

A case of adult self-healing histiocytosis, classified as generalized eruptive histiocytoma, is reported. Ultrastructural investigation of the cytoplasm of tumor cells revealed the presence of many dense and laminated bodies. The origin and possible importance of these bodies are described and discussed, and the need for quantitative study of cytoplasmic markers in histiocytic proliferations of the skin is emphasized.

Adult↗
PubMed1981

Collagen phagocytosis in multicentric reticulohistiocytosis.

A large number of dermal cells engaged in collagen phagocytosis were observed in a case of multicentric reticulohistiocytosis. These cells apparently start to engulf collagen by deep invaginations of the plasma membrane. Fusion of phagosomes containing the engulfed collagen with vesicles probably originating from the Golgi apparatus would give rise to secondary lysosomes. The process of collagen degradation leads to the appearance of fine fibrils and myelin bodies. The presence in the dermis of unusually thick collagen fibers might contribute to this process which appears to occur only under particular physiological and pathological conditions.

Cell Membrane↗
PubMed1980

GAp junctions in skin tumors of molluscum contagiosum.

Thin section, tracer, and freeze-fracture experiments demonstrate that the infection caused by molluscum contagiosum virus implies alterations of cellular contacts in the epidermis, never before observed in cutaneous viroses. These changes are basically represented by a distinctive variation in particle packing of gap junctions, a greater proliferation of these junctions and the presence of a high amount of intracytoplasmic gap junctions. Skin tumors caused by molluscum contagiosum virus appear to be a convenient model to study the morphological and topological variations as well as the turnover of gap junctions in the epidermis.

Freeze Fracturing↗
PubMed1980

Internal organization of plasma membranes during the acantholytic process. A freeze-fracture study.

The internal organization of plasma membranes was studied in seven subjects with pemphigus vulgaris and in one subject with familial pemphigus using the freeze-fracture technique. The results obtained seem to suggest that the acantholytic process is produced in a similar fashion whatever the pathogenic agent and that desmosomes represent the "target" membrane specializations in the acantholytic phenomena. The reduction and eventual disappearance of desmosomal particle aggregations is seemingly accompanied by an increase in gap junctions.

Acantholysis↗