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Biomedical subjects

F Arnold

Publications and source records attributed to F Arnold.

At least 55 records · Page 3Linked 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↗
PubMed1989

Estimating the immigration multiplier: an analysis of recent Korean and Filipino immigration to the United States.

"This article explores the effect of 'chaining' through the petitioning of relatives on the demand for future immigrant visas [to the United States]. The data for the study come from a 1986 survey of 3,911 respondents from the Philippines and the Republic of Korea who were interviewed in Manila and Seoul just after they had received their U.S. immigrant visas. Analyses are conducted to derive different types of multipliers that may be used in estimating the effects of chain migration.... The empirical results for the Philippines and Korea indicate that the potential for future immigration through the family reunification entitlements of the immigration law is lower than has previously been suggested." This is a revised version of a paper originally presented at the 1987 Annual Meeting of the Population Association of America (see Population Index, Vol. 53, No. 3, Fall 1987, p. 385).

Americas↗
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

Differences in the uptake of modified low density lipoproteins by tissue cultured endothelial cells.

Acetylated low density lipoprotein (Ac-LDL) is taken up by bovine aortic and adrenal capillary cells but not by brain capillary cells. This indicates that the uptake of Ac-LDL is not a feature of all types of endothelial cell. A quantitative examination of lipoprotein uptake by flow cytometry showed cells in G2M took up 45% more Ac-LDL than those in G1S. Compared with confluent cultures, sub-confluent bovine aortic cells took up three times as much LDL but Ac-LDL uptake was increased by only 34%. This indicates that the Ac-LDL receptor is not down-regulated to the same extent as that for LDL.

Acetylation↗
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↗
PubMed1985

Measuring the effect of sex preference on fertility: the case of Korea.

Preferences for male or female children or a balanced number of sons and daughters are common throughout the world. The dominant preference is for male offspring, particularly in less developed countries. Strong son preference is often tempered, however, by a desire to have at least one child of each sex. In more developed countries a balance preference is more common, often together with a strong preference for the first child to be a son. Although it is usually assumed that sex preference can substantially influence fertility, some analysts argue that the effect is negligible. An intermediate position is taken by those who say that sex preference may not have much impact at high fertility levels, but that as average family sizes begin to fall, sex preference will become a more important factor in fertility decisions. Despite the keen interest that has been shown in sex preference, there is surprisingly little empirical evidence of its effects on fertility. Moreover, much of the research in this area is methodologically weak. The measures that have been used in the past have been subject to a number of criticisms that call their results into question. This paper proposes a new measure of the effect of sex preference on fertility that avoids many of the problems inherent in other methods. The measure is based on widely available survey data on the sex composition of children and can be used with any measure of fertility or family planning. It can handle any type of sex preference and does not assume a linear relationship between sex preference and fertility.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1984

Tumour angiogenesis factor in urological cancers.

The presence of a tumour angiogenesis factor (TAF) was investigated by bioassay and radioimmunoassay (RIA) in tissue and urine from patients with a variety of urological cancers. TAF was present in the majority of tumours studied by both methods and absent from controls. Our results suggest that RIA of urine for TAF may be applicable as a screening test for bladder cancer.

Adult↗