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Biomedical subjects

F Arnold

Publications and source records attributed to F Arnold.

At least 19 recordsLinked to original sources
PubMed1991

Angiogenesis in wound healing.

Angiogenesis is an essential component of wound healing. Vessel growth is controlled by the local actions of chemical mediators, the extracellular matrix, metabolic gradients, and physical forces. Manipulation of some of these factors can improve healing in experimental wounds. The clinical potential and specific application of 'angiomodulatory' strategies are discussed.

Angiogenesis Inducing Agents↗
PubMed1987

Wound healing: the effect of macrophage and tumour derived angiogenesis factors on skin graft vascularization.

Angiogenic factors prepared from rat Walker 256 mammary carcinoma, (TAF) and activated mouse peritoneal macrophages (MAF), were tested for their ability to stimulate vascularization during healing. They were applied to one of a pair of bilaterally symmetrical, autologous, isotopic, full thickness skin grafts in mice. Blood flow to treated and untreated graft pairs was compared by their uptake of injected 86Rb Cl, at 3 and 7 days after grafting. No difference was detected after treatment with either agent. We conclude that while angiogenic factors are important in vascularization during healing, this normally occurs at a near maximal rate and cannot be further enhanced.

Angiogenesis Inducing Agents↗
PubMed1987

Angiogenic activity in human wound fluid.

Wound drainage fluid from postoperative patients was examined for its ability to induce blood vessel growth using the chick chorio-allantoic membrane (CAM) assay. Sixteen samples from 12 patients were tested. The tests were performed on both whole unfractionated fluid and fluid after separation using diethyl aminoethyl cellulose (DEAE) ion exchange chromatography. All 16 samples were inactive before DEAE-chromatography but a fraction, eluting at between 300-400 mM salt, induced neovascularization in 15 out of 16 samples. These differences were statistically highly significant (p less than 0.001). Angiogenic factor (AF) was detected in fluids obtained from both clean and contaminated wounds, and in patients with benign and malignant disease. As mentioned earlier unfractionated wound fluids were nonangiogenic by themselves and their addition to the active fractions greatly reduced the angiogenic effect of the latter. Therefore we suggest that wound fluid contains both promoters and inhibitors of angiogenesis. The local balance between these may govern the rate of vascularisation during healing.

Angiogenesis Inducing Agents↗
PubMed1985

Angiogenesis induced by degradation products of hyaluronic acid.

Partial degradation products of sodium hyaluronate produced by the action of testicular hyaluronidase induced an angiogenic response (formation of new blood vessels) on the chick chorioallantoic membrane. Neither macromolecular hyaluronate nor exhaustively digested material had any angiogenic potential. Fractionation of the digestion products established that the activity was restricted to hyaluronate fragments between 4 and 25 disaccharides in length.

Allantois↗
PubMed1985

A study of angiogenesis factors from five different sources using a radioimmunoassay.

The use of a radioimmunoassay (RIA) demonstrated that angiogenic factors from human and animal tumours, normal bovine retinas, myocardial infarcts, synovial fluid from patients with joint diseases and wound fluid shared common antigenic determinants. Values for angiogenesis factors expressed as microgram Walker tumour TAF/mg protein varied from 0.8 (wound fluid) to 207 (myocardial infarct). Activated macrophages produced an angiogenic factor which did not cross-react. Normal tissue extracts which were non-angiogenic by the chicken chorioallantoic membrane assay also failed to cross-react in the RIA. The antigenic similarity of angiogenic factors from such a wide variety of sources suggests that, in order to minimize therapeutic side effects, it would be best to use angiogenic agonists and antagonists locally.

Angiogenesis Inducing Agents↗
PubMed1985

Tumour angiogenesis.

Tumours induce the growth of host blood vessels to support their proliferation. This process of angiogenesis is evoked by specific chemical signals. Recognition of these angiogenic factors has led to experimental methods for cancer diagnosis and for inhibiting malignant growth by specifically blocking neovascularisation. The clinical potential of these techniques is discussed.

Angiogenesis Inducing Agents↗
PubMed1979

Height vertigo and human posture.

A theory is presented supporting a geometrical explanation for physiological height vertigo being a distance vertigo through visual destabilization of postural balance when the distance between the eyes and visible stationary contrasts becomes critically large. Physiological and posturographic data obtained under natural height vertigo conditions are consistent with this hypothesis.

Humans↗
PubMed1977

Arthrokinetic nystagmus and ego-motion sensation.

A compelling illusion of body rotation and nystagmus can be induced when the horizontally extended arm of a stationary subject is passively rotated about a vertical axis in the shoulder joint. Lateral nystagmus with the fast phase beating in the opposite direction to the arm movement was found consistently; the mean slow phase velocity increased with increasing actual arm velocity and reached about 15 degrees/sec; the mean position of the eyes was deviated towards the fast phase as in optokinetic nystagmus, and the nystagmus continued after the cessation of stimulation (arthrokinetic after-nystagmus). The existence of an arthrokinetic circularvection and nystagmus indicates a convergence of vestibular and somatosensory afferents from joint receptors. It is concluded that information about joint movements plays an important role within the multisensory processes of self-motion perception.

Adult↗
PubMed1977

[Use of automatic picture processing in clinical-morphological diagnostics].

The use of the automatic elaboration of pictures for the evaluation of microscopic pictures gives the possibility to automise histological and cytological routine examinations and to improve the recognition of morphological findings by quantitative investigations in the medical morphological diagnostics. The effective practical use of the method is bound to certain device-technical prerequisites which are mentioned in short. At the same time a survey of the principal possibilities in the medical morphological diagnostics is given. By the analysis of the digitalised pictures of cells, cell organelles and other tissue structures reproducible quantitative data on outline and texture as well as on the special arrangement of the objects present in the picture are obtained. On the basis of these characteristics it is possible to identify cells, to find perhaps existing subgroupings in cell populations or to perform an automatic preselection of the material to be investigated. At the instance of the normal white differential blood picture the modern possibilities and limits of the method are described.

Blood Cells↗
PubMed1976

[Activity distribution of SDH in liver of mice. A histophotometrical study (author's transl)].

The paper presents histophotometrical measurements of the histochemical SDH reaction with INT as redoxindicator in comparison with biochemical techniques of the determination of SDH activity (with K3[Fe(CN)6] and INT as indicators) and a histochemical method of elution (with INT as indicator). The measurements were performed on liver of mice. For each method absolute values of activity (10(-9) mol substrat/min-mg liver) are calculated as relative values of activity [%]. The standard deviation of the biochemical methods is approximate +/- 4%, of the histochemical methods +/- 8%. The smallest value of detection is 2.5-10(-14) mol formazan of histophotometrical measurement. The correspondence between the measurements of the relative values of activity by the described methods was secured by statistical tests. A statistically significant proportion of activities between periportal zone and central zone like 100:82 was determinated by histophotometrical measurement.

Animals↗