PubMed Health⌕ Search

Biomedical subjects

K Lehner

Publications and source records attributed to K Lehner.

At least 55 records · Page 3Linked to original sources
PubMed1987

Selective digital subtraction arteriography in necrosis of the femoral head.

Selective digital subtraction arteriographic investigations of the arteries of the femoral head in 31 patients with traumatic and 34 patients with nontraumatic femoral head necrosis (FHN) were compared with investigations in a control group of 35 patients without hip disease. In the control group and in patients with nontraumatic FHN atypical arteriographic findings were found only in one third of cases. In traumatic FHN, however, vascular alterations could be detected in 97% of cases. This evidence suggests that damage to the femoral head vessels is a major etiological factor in traumatic, but not in nontraumatic, FHN. In late arterial phases of DSA a perinecrotic hypervascularization was the common feature in all nontraumatic necroses and could be observed in 71% of traumatic necroses. Its pathophysiological mechanism is discussed.

Adolescent↗
PubMed1987

DSA--control of implanted devices for arterial hepatic perfusion.

In contrast to conventional film angiography, the perfusion pattern of hepatic arterial chemotherapy was consistently visualized by DSA in 40 patients with implanted Infusaid pump or Port-A devices. Incomplete perfusion of a liver region by the cytotoxic agent was recognized by DSA as accurately as by nuclide scintigraphy. Furthermore, DSA appeared to be more sensitive in determining aberrantly perfused extrahepatic regions; this was especially true when there was a nonligated right hepatic artery. Specific details of vascular lesions and associated complicating events also could be satisfactorily analyzed by DSA only.

Adult↗
PubMed1987

[Imaging of femur head necrosis using MR tomography].

Magnetic resonance tomography (MR) was used to examine the femoral heads of 20 normals and of 56 patients with diseases of the femoral head, including Perthe's disease (four cases), adult necrosis of the femoral head (39 cases) and pain of unknown cause (13 cases). Femoral head necrosis and Perthe's disease regularly produce reduced signal intensity. The localisation of the areas of necrosis can be determined accurately in the coronary and sagittal plane. In 11 femoral heads, necrosis could be demonstrated unequivocally by MR in the presence of normal radiographic findings. Follow-up of nine patients with negative MR findings and indefinite symptoms confirmed the absence of necrosis.

Adult↗
PubMed1987

[MRI in osteochondrosis dissecans].

The osseous manifestations of osteochondrosis dissecans are well demonstrated by conventional and computerised tomography. Beyond that, magnetic resonance imaging (MRI) is effective in evaluating the vitality and loosening of an osseous dissecate. Subchondral cavities and cartilaginous defects are detected with high accuracy. Further, MRI seems to be a useful method in childhood to differentiate a variant irregularity of the osseous articular surface from definite osteochondrosis dissecans.

Adolescent↗
PubMed1987

[The MRT demonstration of bone marrow changes in intervertebral disk degeneration].

Amongst 214 patients with degenerative disc disease, MRT showed focal fat deposition in the vertebral marrow close to the end plate in 87 (41%). The appearances and distribution of these zones is described. Recognition of these common changes is important in differential diagnosis between inflammatory and neoplastic processes.

Bone Marrow↗
PubMed1986

[Posterior defects of the patella on CT arthrograms. Detection and differential diagnosis].

Changes of the posterior bony and cartilaginous surfaces of the patella as seen on CT arthrograms are described in the case of bipartite patellae, fractures and ossification defects. Contrary to present opinion, cartilaginous lesions are frequently seen on CT arthrograms. This is also true for discreet and partial ossification defects which are not visible on conventional x-rays and are described here for the first time. The aetiology, morphogenesis and clinical examples are discussed.

Adolescent↗
PubMed1985

[Imaging of the Achilles tendon on the computed tomogram. Normal findings and pathological changes].

Ligaments and tendons, including the Achilles tendon, show the highest density among normal soft tissue structures in the body. Traumatic and degenerative changes of the Achilles tendon are often associated with marked thickening and reduction in density associated with increased opacity of the space in front of the Achilles tendon. These changes are easily demonstrated by CT, whereas conventional radiological techniques only show non-specific changes. Twenty-five patients were examined, including nine with pain, seven following rupture of the Achilles tendon and nine post-operative controls; it was found that CT can add information important for the diagnosis and treatment planning of abnormalities of the Achilles tendon.

Achilles Tendon↗
PubMed1985

[Normal findings and pathological changes of the patellar ligament in the computer tomogram].

In the computer tomogram, the normal patellar ligament appears as a flat band with an average density of 110 HE. After trauma and also after chronic overloading, the cross-section increases, whereas the density decreases. CT is superior to conventional x-ray diagnosis and to sonography in respect of detecting and differentiating of circumscript changes in the patellar ligament.

Adult↗
PubMed1981

Aging in vitro and D-glucose uptake kinetics of diploid human fibroblasts.

By use of a rapid technique, initial rates of D-glucose transport were obtained during the lifespan in vitro of a commercially available strain of human embryo lung fibroblasts (Flow 2000). The apparent Km of the D-glucose carrier did not change during senescence in vitro: x = 1.8 mM (range 1.3-2.3) in phase II, x = 1.8 mM (range 1.5-2.2) in phase III. Transport rates remained constant in stationary phase II cultures, which had completed between 30% and 80% of their replicative lifespan. A wide variation, however, was observed in terminally differentiated cells (phase III), which showed a two- to threefold increase in average cell size and protein content. In some senescent cultures, glucose transport calculated on a per cell basis was also two- to threefold increased, while it was strongly decreased (-75%) in others. When calculated per unit of cell water, protein, and surface area, respectively, transport rates in phase III cultures ranged from values established for stationary phase II cultures down to very low values. Detaching cells flushed off from senescent cultures did not show measurable rates of glucose transport into the inulin impermeable cell space. Present evidence argues against the idea that an impairment of D-glucose transport might precede loss of replicative potential in aging human fibroblasts. Instead our data indicate that the transport capacity of cell membrane finally decreases during postreplicative senescence in terminally differentiated cells.

Biological Transport↗
PubMed1980

D-Glucose transport into suspended human fibroblasts. Rapid measurement of uptake by silicone oil filtration centrifugation, and comparison of different cell detachment procedures.

The uptake of 14C-labeled D-glucose into the cellular space of human diploid fibroblasts (Flow 2000)--grown to confluency and detached with trypsin-EDTA--was studied using silicone-oil-layerfiltering centrifugation. This method is rapid enough to enable the determination of initial transport rates, which are not complicated by subsequent metabolism of the hexose taken up into the cells. D-Glucose uptake shows saturation kinetics with a Km of 1.8mM and maximal transport capacity of 4--8 nmol/(10(6) cells x min) at 20 degrees C. This saturable transport system is responsible for at least 80% of the total glucose taken up into the cells in the concentration range tested (0.1--10mM D-glucose in incubation medium). The glucose carrier is stereo-specific, is independent of sodium and potassium ions, and is inhibited by cytochalasin B. Its temperature dependence reveals an activation energy of 3 1 kJ/mol (7.5 kcal/mol; Q10 approximately equal to 1.5). As detachment of the cells from the culture flasks is necessary for applying silicone-layer-filtering centrifugation, various detachment procedures were tested. In the enzymatic procedure cells were treated with either trypsin or pronase. In the chelating method, Ca2+ and Mg2+ ions were chelated by EDTA and K+ ions with sodium tetraphenylborate. For mechanical detachment, cells were grown initially on plastic foil. After each of these detachment procedures the transport of D-glucose was the same. It is therefore concluded that this method of rapid measurement of D-glucose uptake in suspended human fibroblasts may serve as an alternative to the uptake measurement with glucose analogues in attached cells when studying the hexose transport system in human diploid fibroblasts.

Biological Transport, Active↗
PubMed1979

[Investigations on combined injuries, 24th communication: response of blood circulation and respiratory function in mice upon whom was inflicted whole-body irradiation in combination with open skin wounds (author's transl)].

Combined injuries were inflicted upon NMRI-mice, hurting each with an open skin wound subsequent to sublethal exposition to X-rays. Lethality among animals with combined injuries was between 40 and 60%, while animals only irradiated and those with only a skin wound had lethalities between 10 and 20% and 0%, respectively. Blood circulation and respiration of animals injured with combined lesions were studied in an attempt to understand the cause of the high lethality in this group. The blood volume and the oxygen transport capacity were drastically reduced in animals with combined injuries as compared to those in animals only irradiated, although plasma volume, vascular permeability and distribution of the blood volume remained similar in both groups. Analyses of gases and acid/base composition of blood revealed neither respiratory nor metabolic acidosis. These findings indicate that combined injuries hardly impair blood circulation and respiratory function.

Acid-Base Equilibrium↗