PubMed Health⌕ Search

Biomedical subjects

A Vogel

Publications and source records attributed to A Vogel.

16 recordsLinked to original sources
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↗
PubMed1978

Elastic fibers in the tunica propria of the seminiferous tubules. Light and electron microscopic investigations.

Histological examination of numerous biopsies from mature testes, repeatedly showed irregularities of the elastin staining in the tunica propria of the seminiferous tubules. Even when abundant elastic fibers were visible by light microscopy, no elastic fibers were demonstrable in the electron microscope in ultrathin sections of testicular tubules embedded in Epon and contrasted with phosphotungstic acid (PTA). In 43 biopsies from 22 men aged 17-39 years (19 investigations of sterility and three patients with hypogonadotropic hypogonadism) we therefore checked for the occurrence of elastic fibers in the wall of the seminiferous tubules. Matrix loci of elastic fibers could indeed by demonstrated by electron microscopy using PTA and potassium permanganate (KMnO4), but only after embedding in araldite. Under these conditions, light and electron microscopic findings agreed with each other. The appearances of moderate and severe testicular tubular atrophy differed slightly from one another with regard to the amount of elastin. In the "Sertoli cells only syndrome", elastic fibers were demonstrable only outside the hyalinized inner layer. In the Klinefelter syndrome, only "uncertain" elastin loci were present, but greatly increased microfibrils were to be seen using the electron microscope. No elastic elements and only very sparse microfibrils were present in the tunica propria of the tubules of young men with hypogonadotropic hypogonadism.

Adolescent↗
PubMed1978

Coordinate control of 3T3 cell proliferation by platelet-derived growth factor and plasma components.

DNA synthesis and cell division were measured in Swiss mouse 3T3 cells cultured in different concentrations of cell-free plasma-derived serum and increasing amounts of a platelet-derived growth factor. In plasma-derived serum alone, the cells were quiescent and they were arrested in the Go/G1 phase of the cell cycle. Addition of a platelet-derived growth factor to quiescent cells maintained in plasma-derived serum stimulated both DNA synthesis and cell division. When plasma components were present at high concentration (5%, vol/vol), the amount of platelet factor added to the cultures determined the number of cell doublings. Plasma-derived molecules were required for the platelet factor to stimulate DNA synthesis and cell division in the maximal number of cells. In addition, plasma components had to be present for recently divided cells to respond to the platelet factor. When 3T3 cells were cultured in excess platelet factor and limiting amounts of plasma-derived serum (0.5%, vol/vol), the cells underwent one doubling and then ceased to proliferate. Addition of fresh plasma-derived serum to these cells induced a second round of cell division. Plasma components and the platelet-derived growth factor acted in a coordinate fashion to regulate the proliferation of Swiss 3T3 cells.

Blood Platelets↗
PubMed1977

[Plasma concentrations after injection or infusion of phenytoin (author's transl)].

Intravenous injection of 3 mg/kg phenytoin produced plasma concentrations of 4.2 mug/ml in five volunteers, which were below the concentration of 10-20 mjg/ml necessary for effective antiarrhythmic and antiepileptic treatment. Intravenous injection of 250 mg phenytoin followed by infusion of 750 mg phenytoin in a mean dosage of 1.7 mg/kg x h in nine patients with epilepsy produced plasma concentrations of 10.2 resp. 15.1 mug/ml after 4 resp. 8h. An oral maintenance therapy of 5-6 mg/kg is suggested. Therapeutic plasma concentrations were rapidly reached with this regimen.

Adult↗
PubMed1977

[Experimental studies with radionuclides on the functional behavior of the blood circulation system in the dental pulp].

Using a special semiconductor detector probe and the radiopharmacon DF32P, the author measured the blood supply in the dental pulp. To test the sensitivity of the measuring system, adrenaline was injected for the purpose of vasoconstriction. The resulting change in blood volume is demonstrated by measuring the decrease of the pulse rates during a given period of time.

Animals↗
PubMed1977

[Evaluation of epithetic restoration].

Starting from an analysis of facial prostheses applied during the years 1967-1977, the authors report of the therapeutical success. The evaluation involved not only objective criteria but also psychical problems of the face-injured patients. Priorities of stomatological efficacy are established with regard to insertion, adaptation and the postadaptive phase.

Adaptation, Psychological↗
PubMed1976

Diagnosis and treatment of acute gastrointestinal haemorrhage in a small district hospital.

Ninety-eight consecutive patients admitted to a small district hospital because of acute gastrointestinal haemorrhage have been studied. Patients with haematemesis and/or melaena were treated with antacids and tranexamic acid from the very beginning and were examined with early panendscopy. All patients were closely observed in an ordinary medical ward by a staff especially trained to handle acute gastrointestinal bleeding. Seven patients required acute surgery. The overall mortality was 4.1%. It is concluded that acute gastrointestinal haemorrhage can be successfully handled with modern diagnosis and treatment in a small hospital.

Adult↗
PubMed1975

Isolation and characterization of revertant cell lines. VII. DNA synthesis and mitotic rate of serum-sensitive revertants in non-permissive growth conditions.

The ability to synthesize DNA and enter mitosis was studied in Balb/c and Swiss 3T3 cells, SV40 and MSV-transformed 3T3 cells and revertants of these transformed cells in cultures of different serum concentrations and cell densities. Three ways were found by which cells were able to maintain a constant cell number in non-permissive growth conditions: cessation of DNA synthesis, synthesis of DNA coupled with failure to enter mitosis, and the slow traverse of the cell cycle coupled with cell shedding. Growth control of the revertant of an MSV-transformed Balb/3T3 cell most closely resembled that of Balb or Swiss 3T3. This line did not grow in 1% serum and did not synthesize DNA in either non-permissive condition. Serum-sensitive revertants of SV40-transformed 3T3 cells are also unable to grow in 1% serum and also do not grow beyond confluence in 10% serum, but these cells differ from 3T3 in the manner in which this growth arrest is accomplished. In 1% serum, revertants synthesize DNA but do not enter mitosis. At confluence in 10% serum, they slowly traverse the cell cycle, with dividing cells replacing cells that are shed into the medium.

Animals↗
PubMed1975

Ehlers-Danlos syndrome in two siblings with deficient lysyl hydroxylase activity in cultured skin fibroblasts but only mild hydroxylysine deficit in skin.

Two siblings suffered from Ehlers-Danlos syndrome characterized by skin fragility, joint laxity and dermal hyperelasticity. The association with microcornea and muscle hypotonia allowed the preliminary classification into type VI according to McKusick. Ultrastructure analysis of skin biopsies revealed poor integration of collagen fibrils into fibres; accordingly, the texture of the connective tissue appeared irregular. Lysyl hydroxylase activity of cultured skin fibroblasts was markedly reduced in the cells of the two patients. Preliminary studies revealed intermediate activity in the cells cultured from the skin of the parents. This finding suggested an autosomal recessive mode of inheritance. Unexpectedly and in contrast to the 3 cases reported in the literature, the hydroxylysine deficit in the patients' skin was, for reasons not yet understood, only mild. Therefore, amino acid analysis of skin is not adequate for the diagnosis of lysyl hydroxylase-deficient Ehlers-Danlos syndrome type VI.

Adolescent↗