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Biomedical subjects

A Vogel

Publications and source records attributed to A Vogel.

At least 127 records · Page 7Linked to original sources
PubMed1984

[Becker nevus. A clinico-histologic-electron microscopy study of 39 patients].

The study presented here is based on the clinicopathological and electron microscopical analysis of 39 patients with Becker's nevus (BN). The clinical picture is variable and we therefore suggest the following three types be distinguished: (1) the melanotic type, (2) the hypertrichotic type, and (3) the mixed type. In BN the sensitivity reaction was often diminished. Among the skin eruptions other than BN, we would like to stress that 12% of our patients showed a malignant melanoma. Histopathology concerns both epidermal and dermal structures. The electron microscopic findings corresponded well with those by light microscopy. As far as we know, the changes in collagen fibrils are demonstrated for the first time in this study.

Adult↗
PubMed1984

[Hair cylinders].

Hair casts (peripilar keratin casts) of two girls are investigated by electron microscopy. The 31 cases of hair casts so far known are briefly summarized. The etiology seems to be heterogeneous. The ultrastructural study of the casts reveals three layers. Two of them can easily be interpreted as internal root sheet, the third with parts of the outer root sheet, rather than with parts of the epithelium of the follicular infundibulum, as was suggested by Kligman in 1957.

Child↗
PubMed1983

[Development of Achilles tendon rupture in skiing].

This is an analysis of decline of rupture of the Achilles tendon in skiing while there is a steady increase of skiing injuries. Three groups, equipped with three different types of ski boots were observed once on a plane slope on the other hand on a bump track. The simultaneous size of angle of knee and ankle was measured by telemetry. The high plastic ski boot, which obstructs the ankle forward and lateral is apart from the rise of heel in the boot, the safety binding and the new skiing style the main reason for decline of rupture of the Achilles tendon in skiing.

Achilles Tendon↗
PubMed1982

Hyperpigmented small spots induced by long-term PUVA therapy. A clinical, light and electron microscopic study.

Among 308 photochemotherapy (PUVA)-treated patients, 15 psoriatics and 1 case of mycosis fungoides developed persistent disseminated hyperpigmented small spots at the trunk and limbs as a side effect of the therapy. The histological, histochemical and electron microscopical studies performed on 5 of the patients revealed a greatly increased number of melanocytes in the macules, hyperactivity of the melanocytes and increased transfer of pigment to dermis and keratinocytes. Moreover, binucleated cells were found as well as multifarious signs of melanocytic damage in varying degrees. Similar alterations but less pronounced were observed in the intermacular skin. Some of the changes could be recognized even 7 months after the treatment had been stopped. The PUVA spots are compared with other etiologically light-dependent hyperpigmentations.

Adult↗
PubMed1982

[Systemic cutis laxa-like pseudoxanthoma elasticum].

According to Pope the pseudoxanthoma elasticum (PXE) can be divided into four types using clinical genetical criteria. In contrast to the classical form the recessive type II is not only characterized by a wrinkeled appearance and laxity of the skin, furthermore there are no clinical symptoms indicating visceral disease. We report two patients with cutis laxa-like skin. In addition the patients suffered from pathological changes of the eye. In one of them an alteration of the peripher vascular system could be observed.

Adult↗
PubMed1981

Evidence for two forms of reverse transcriptase in human placenta of a patient with breast cancer. Purification and biochemical characterization of the enzymes.

Two DNA polymerases with properties of viral RNA-directed DNA polymerase were found in the placenta of a patient with breast cancer. Both enzyme activities were purified by column-chromatographic procedures or by preparative isoelectric focusing. The most distinguishing feature of the two enzymes is their specificity to transcribe (rA)n . (dT)12 or (rC)n . (dG)18. The two enzymes differ with respect to their elution profiles from the phosphocellulose column, isoelectric point, molecular weight, bivalent-cation requirements and thermal stability. Serological analysis of the (rA)n . (dT)12-activated enzyme showed that this enzyme is immunologically not related to DNA polymerase-gamma, or to any of the reverse transcriptases purified from retroviruses of avian, murine and subprimate origin. However, the activity of this enzyme was neutralized by antibodies to reverse transcriptase purified from human spleen of a patient with myelofibrosis [Chandra & Steel (1977) Biochem. J. 167, 513-524]. Attempts to purify reverse transcriptase of normal human placenta were repeatedly unsuccessful. Once the crude homogenate of normal placenta was freed from endogenous nucleic acids, no (rC)n . (dG)18-dependent activity cold be detected.U

Breast Neoplasms↗
PubMed1981

[Herlitz, severe generalized atrophic epidermolysis bullosa. Description and genealogic clarification of 4 new cases from Unterwalden canton].

Four infants with congenital epidermolysis bullosa letalis Herlitz were admitted between 1971 and 1978 to the Children's Hospital, Lucerne. All four were from three related families from the same valley in the Canton of Unterwalden and died before the age of one year. Histological and ultrastructural examinations of skin specimens confirmed the diagnosis, but an attempt to detect heterozygous carriers by the same method failed. Genealogical analysis revealed a fourth affected family one generation back and multiple consanguinity among three of the four families, according to an autosomal-recessive inheritance. The pathogenesis, clinical findings, therapy and genetics in this disease are discussed, together with the particular population genetics of the area concerned.

Consanguinity↗
PubMed1980

[The Werner syndrome].

Werner's syndrome, also known as "progeria adultorum", manifests itself in young adults. They appear older than their chronological age. Characteristically, there is atrophy in the distal extremities and the face. There is progressive scleropoikiloderma and hyperkeratosis on the foot soles. In the face, there is frequently a "bird-like" expression. Other characteristics are premature graying and early loss of hair, juvenile cataracts, hypogonadism, diabetic symptoms, arteriosclerosis, osteoporosis, small stature with characteristic features, muscle atrophy and cardiac abnormalities. The disease is inherited in an autosomal recessive way. Pathogenesis is unclear. In the following paper, we are reporting the case of a 29 year old saleswoman, who complained of cramps in the calves, and presented the typical symptoms of Werner's syndrome.

Adult↗
PubMed1980

Role of serum components in density-dependent inhibition of growth of cells in culture. Platelet-derived growth factor is the major serum determinant of saturation density.

The effects of platelet-derived growth factor and plasma components on saturation density in cultures of 3T3 cells were investigated. Both of these components of whole blood serum affect saturation density; however, when 3T3 cells become quiescent at high density in medium containing whole blood serum, only platelet-derived growth factor and fresh whole blood serum are capable of stimulating proliferation. Addition of fresh plasma- derived serum has little effect on cell growth. These results suggest that the platelet factor is the major determinant of saturation density in cultures of 3T3 cells maintained in medium supplemented with whole blood serum. Experiments were performed to investigate the mechanism by which platelet-derived growth factor regulates saturation density. We investigated the possibilities of inactivation of growth factors by proliferating cells, and the effects of cell density on the response of 3T3 cells to platelet-derived growth factor. The amount of platelet- derived growth factor required to initiated DNA synthesis increases with increasing cell density. Some inactivation of growth factors by growing cells was detected, but this depletion was only evident at high cell density. We propose that density-dependent inhibition in cultured 3T3 cells is the result both of an increased requirement for the platelet- derived growth factor as the cultures become more crowded and of inactivation of growth factor activity by growing cells.

Animals↗
PubMed1979

Single cilia in the articular cartilage of the cat.

Single cilia (SC) in the articular cartilage of the cat are described with regard to structure, frequency and intracellular location. Comparison is made with their occurrence in the cartilage of other species or in other tissues; special consideration is given to their developmental stages. In the 1-year-old cat examined, about 20% of the cells showed SC with a predominantly intracellular course and some of them did not reach the extracellular space at all. Cross-sections of the proximal region of SC reveal the familiary 9+0 pattern; towards the distal end, the number of doublets and the diameter of the shaft are decreasing. It is concluded that most of the SC encountered are undergoing involution.

Animals↗
PubMed1979

Abnormal collagen fibril structure in the gravis form (type I) of Ehlers-Danlos syndrome.

The Ehlers-Danlos syndrome (EDS) is a clinically, genetically, and biochemically heterogeneous group of disorders characterized by generalized connective tissue abnormalities. We studied collagen fibrils by electron microscopy in the dermis of nine individuals with clinical findings consistent with type I Ehlers-Danlos syndrome. In all patients the collagen fibrils had an increased mean diameter (13 to 40%) and showed a higher degree of variability in width and shape than collagen fibrils from controls. Approximately 5% of the fibrils were much wider (up to 500 nm. versus 90 nm.), had a highly irregular outline when viewed in cross-section, and were spiraled and fragmented in longitudinal view. The periodicity of banding was normal. The mode of inheritance was dominant in five patients, probably recessive in two, and could not be determined in the remaining two. Despite genetic heterogeneity among these patients with type I Ehlers-Danlos syndrome, the ultrastructural findings are indistinguishable and do not allow discrimination in sporadic cases between the recessive and the more common dominant form. We conclude that abnormalities of fibrillogenesis are heterogeneous in origin; some might be due to primary defects in collagen whereas others may result from alterations of noncollagenous extracellular matrix components that influence collagen fibril formation.

Adolescent↗