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Biomedical subjects

H Keller

Publications and source records attributed to H Keller.

At least 235 records · Page 13Linked to original sources
PubMed1985

High post-translational modification levels in type II procollagen are not a consequence of slow triple-helix formation.

The kinetics of triple helix formation of newly synthesized type II procollagen in chick embryo sternal cartilage cells were determined. The data obtained were in agreement with a model for triple helix formation in cellulo proposed recently (Bruckner et al., 1981). The time required to produce fully triple helical type II procollagen in cartilage cells was only 30% longer than for type I procollagen in tendon cells. Therefore, the several-fold increase in post-translational modification observed for type II collagen as compared to type I collagen cannot be attributed solely to slow helix formation but rather is a result of higher levels of enzymic activity of post-translational modification present in cartilage cells.

Animals↗
PubMed1985

Influence of native collagen on the cell cycle.

The influence of native collagen-solutions on the cell cycle of human-fibroblasts was investigated. The results point out that the phase of cell-specific function is distinctly lengthened to the debit of a reduced rate of mitosis. That seems to be desirable, because the cells of the implantation-layer would produce more rapidly and augmentedly their cell-specific product--usually collagen--and incorporation of the implanted material would occur quite earlier. This effect seems also to be responsible for the promotion of granulation of "Dermodress", a fleece of collagen I for temporary covering of debrided areas (5).

Bioprosthesis↗
PubMed1985

Morphological and biochemical responses of leukocytes in chemokinesis and chemotaxis.

Morphological changes associated with leukocyte chemokinesis and chemotaxis are briefly described. Leukocyte stimulation by chemokinetic and chemotactic factors (cytotaxins) elicits various biochemical responses including ligand-receptor interactions, ion fluxes, alterations in phospholipid and arachidonic acid metabolism, cyclic nucleotides, protein phosphorylation and reorganization of the cytoskeleton. These biochemical processes may be related to signal transduction, the effector mechanisms of directional locomotion or possibly other leukocyte responses which occur in parallel.

Animals↗
PubMed1985

[Tachycardias caused by double ventricular responses and unusual atrioventrio-ventricular relations in linear dissociation of the AV node].

Noninvasive recordings in a 69-year-old woman showed phasic shifts between two distinct PR intervals of about 0.21 and 0.58 s suggestive of dual AV nodal conduction in the presence of two intranodal pathways. Episodes of tachycardia exhibited a one to two relationship between P waves and QRS complexes, with the same short and long PR intervals interpreted as simultaneous anterograde fast and slow conduction via the two AV nodal pathways, leading to a double ventricular response to single P waves. Various mechanisms of transition from short to long or long to short conduction times and concealed conduction phenomena could be demonstrated supporting the concept of two functionally separated intranodal pathways.

Aged↗
PubMed1985

[Estimation of pulmonary capillary mean pressure using TM-mode echocardiography].

The feasibility of estimating the mean pulmonary capillary pressure by simultaneous noninvasive recording of the ECG, the aortic and mitral valve echocardiogram was tested in 50 patients with miscellaneous heart lesions. The Q-MVC-/AVC-E ratio was measured from the onset of the QRS-complex in the ECG, the closure point of the aortic valve, the early diastolic opening of the anterior mitral valve (E-point) and the systolic closure of the mitral valve leaflets on the echocardiogram (C-point). A linear correlation exists between the mean pulmonary artery wedge pressure and the Q-MVC-/AVC-E ratio (n = 50, r = 0.75, p less than 0.001). The echocardiographic derivate index (Q-MVC-/AVC-E) is useful in assessing an elevated left ventricular filling pressure, but the individual data revealed variation in the predicted relation between Q-MVC-/AVC-E and left ventricular end-diastolic pressure. The Q-MVC-/AVC-E ratio is not a useful parameter in predicting left ventricular end-diastolic pressure in patients suffering from a left ventricular aneurysm or an acute transmural myocardial infarction with extensive regional abnormal wall motion. Many criteria such as mitral valve disease, atrial fibrillation, atrioventricular block and left bundle-branch block suggest that the Q-MVC-/AVC-E ratio is of limited clinical value. The left atrial emptying index was measured by using the amplitude of the posterior aortic wall motion occurring in the first third of the passive emptying period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

[Ostium stenosis of both coronary arteries and latent hypothyroidism as sequelae of radiotherapy in Hodgkin disease].

Premature arteriosclerosis following irradiation is a known experimental and clinical phenomenon. Although the heart was once considered a relatively radioresistant organ, now all components, including the coronary arteries, are recognised as possible targets of radiation injury. We present a 40-year-old women who received extensive neck and thoracic radiation for treatment of Hodgkin's disease. Ten years later she developed severe coronary artery disease with ostium stenosis of the left and right coronary arteries, as well as subclinical hypothyroidism.

Adult↗
PubMed1984

[Immunogenicity of a new, highly purified, highly concentrated duck-embryo rabies vaccine].

The protective value and safety of human diploid cell strain rabies vaccine (HDCV) are well established [6, 8, 11]. At present, however, the high cost and small yields of HDCV has restricted its use, particularly in developing countries where rabies vaccine is needed in large amounts. The inexpensive duck embryo rabies vaccine (DEV), also prepared with the Pitman -Moore strain, is potent and generally safe despite occasional allergic complications [9, 13]. The vaccine has been used with success in several million doses during recent decades [12, 14]. Administered according to the prescribed schedule (14 initial inoculations and 3 boosters), the vaccine has been shown to provide protective antibody titers in pre- and post-exposure use [7, 10]. On the other hand, the immunogenicity of this vaccine did not shorten the administration schedule in a similar way to HDCV. Thus, prior clinical studies using the reduced WHO immunization scheme demonstrated that a concentrated and partially purified DEV containing less than 2.5 IU/ml of rabies antigen elicited sufficient neutralizing antibodies in only 75% of vaccinees [3]. Gl uck et al. [4] clarified the reason for this low immunogenicity: We demonstrated that only about 30-50% of the glycoprotein (GP) in DEV was present on the surface of virus particles. GP, a component of the rabies virus envelope, is the antigen responsible for the induction of neutralizing antibodies. During virus production a non-immunogenic soluble GP may also accumulate. Non-immunogenic GP may be coextracted during vaccine preparation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

[Campylobacter infections].

In recent years the microaerophil organisms of the genus Campylobacter have been cultured with increasing frequency, thanks to more appropriate methods for isolation from fecal cultures. These organisms have been shown to be important causes of acute diarrheal disease, usually with spontaneous recovery. They also are accepted as agents capable of causing serious systemic infection, mainly in patients debilitated by chronic disease. The incidence of Campylobacter enteritis in Switzerland, its epidemiology, the clinical picture of Campylobacter infections and diagnostic and therapeutic problems are briefly reviewed.

Aged↗
PubMed1984

Dislocation of an artificial knee component due to extraordinary function.

A rare complication, namely dislocation of a knee component without fracture of the prosthesis and not caused by a trauma, is described in a patient who was treated for osteosarcoma of the femur. Probably the dislocation, which occurred 2 years postoperatively, was caused by an extraordinary function of this prosthesis. A partial revision of the prosthesis was performed. The newly designed knee component, which prevents dislocation, is described.

Child↗