Chronic obstructive pulmonary disease (COPD) remains a major public health problem. It is the fourth leading cause of chronic morbidity and mortality in the United States, and is projected to rank fifth in 2020 in burden of disease worldwide, according to a study published by the World Bank/World Health Organization. Yet, COPD remains relatively unknown or ignored by the public as well as public health and government officials. In 1998, in an effort to bring more attention to COPD, its management, and its prevention, a committed group of scientists encouraged the U.S. National Heart, Lung, and Blood Institute and the World Health Organization to form the Global Initiative for Chronic Obstructive Lung Disease (GOLD). Among the important objectives of GOLD are to increase awareness of COPD and to help the millions of people who suffer from this disease and die prematurely of it or its complications. The first step in the GOLD program was to prepare a consensus report, Global Strategy for the Diagnosis, Management, and Prevention of COPD, published in 2001. The present, newly revised document follows the same format as the original consensus report, but has been updated to reflect the many publications on COPD that have appeared. GOLD national leaders, a network of international experts, have initiated investigations of the causes and prevalence of COPD in their countries, and developed innovative approaches for the dissemination and implementation of COPD management guidelines. We appreciate the enormous amount of work the GOLD national leaders have done on behalf of their patients with COPD. Despite the achievements in the 5 years since the GOLD report was originally published, considerable additional work is ahead of us if we are to control this major public health problem. The GOLD initiative will continue to bring COPD to the attention of governments, public health officials, health care workers, and the general public, but a concerted effort by all involved in health care will be necessary.

https://www.who.int/respiratory/copd/GOLD_WR_06.pdf

Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary.

CARDIOVASCULAR disease remains the chief cause of death in the United States and Western Europe, and atherosclerosis, the principal cause of myocardial and cerebral infarction, accounts for the majority of these deaths.1 This review, like its predecessor,2 will not attempt to cover all literature on atherosclerosis. In a previous review of the pathogenesis of atherosclerosis,2 Glomset and I discussed various hypotheses of atherogenesis2 3 4 5 6 7 and emphasized the importance of intimal smooth-muscle proliferation as the key event in the development of the advanced lesions of atherosclerosis. The response-to-injury hypothesis of atherogenesis2 3 4 5 6 proposes that "injury" to the endothelium is the initiating event in . . .

The Pathogenesis of Atherosclerosis — An Update

This report is the continuation of two earlier reports that defined human arterial intima and precursors of advanced atherosclerotic lesions in humans. This report describes the characteristic components and pathogenic mechanisms of the various advanced atherosclerotic lesions. These, with the earlier definitions of precursor lesions, led to the histological classification of human atherosclerotic lesions found in the second part of this report. The Committee on Vascular Lesions also attempted to correlate the appearance of lesions noted in clinical imaging studies with histological lesion types and corresponding clinical syndromes. In the histological classification, lesions are designated by Roman numerals, which indicate the usual sequence of lesions progression. The initial (type I) lesion contains enough atherogenic lipoprotein to elicit an increase in macrophages and formation of scattered macrophage foam cells. As in subsequent lesion types, the changes are more marked in locations of arteries with adaptive intimal thickening. (Adaptive thickenings, which are present at constant locations in everyone from birth, do not obstruct the lumen and represent adaptations to local mechanical forces). Type II lesions consist primarily of layers of macrophage foam cells and lipid-laden smooth muscle cells and include lesions grossly designated as fatty streaks. Type III is the intermediate stage between type II and type IV (atheroma, a lesion that is potentially symptom-producing). In addition to the lipid-laden cells of type II, type III lesions contain scattered collections of extracellular lipid droplets and particles that disrupt the coherence of some intimal smooth muscle cells. This extracellular lipid is the immediate precursor of the larger, confluent, and more disruptive core of extracellular lipid that characterizes type IV lesions. Beginning around the fourth decade of life, lesions that usually have a lipid core may also contain thick layers of fibrous connective tissue (type V lesion) and/or fissure, hematoma, and thrombus (type VI lesion). Some type V lesions are largely calcified (type Vb), and some consist mainly of fibrous connective tissue and little or no accumulated lipid or calcium (type Vc).

A Definition of Advanced Types of Atherosclerotic Lesions and a Histological Classification of Atherosclerosis A Report From the Committee on Vascular Lesions of the Council on Arteriosclerosis, American Heart Association

Representatives from many countries serve as a network for the dissemination and implementation of programs for diagnosis, management, and prevention of COPD. The GOLD Board of Directors is grateful to the many GOLD National Leaders who participated in discussions of concepts that appear in GOLD reports.

Global initiative for chronic obstructive lung disease.

Matrix metalloproteinases (MMPs) are a family of nine or more highly homologous Zn(++)-endopeptidases that collectively cleave most if not all of the constituents of the extracellular matrix. The present review discusses in detail the primary structures and the overlapping yet distinct substrate specificities of MMPs as well as the mode of activation of the unique MMP precursors. The regulation of MMP activity at the transcriptional level and at the extracellular level (precursor activation, inhibition of activated, mature enzymes) is also discussed. A final segment of the review details the current knowledge of the involvement of MMP in specific developmental or pathological conditions, including human periodontal diseases.

Matrix Metalloproteinases: A Review

Platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-beta) markedly potentiate tissue repair in vivo. In the present experiments, both in vitro and in vivo responses to PDGF and TGF-beta were tested to identify mechanisms whereby these growth factors might each enhance the wound-healing response. Recombinant human PDGF B-chain homodimers (PDGF-BB) and TGF-beta 1 had identical dose-response curves in chemotactic assays with monocytes and fibroblasts as the natural proteins from platelets. Single applications of PDGF-BB (2 micrograms, 80 pmol) and TGF-beta 1 (20 micrograms, 600 pmol) were next applied to linear incisions in rats and each enhanced the strength required to disrupt the wounds at 5 d up to 212% of paired control wounds. Histological analysis of treated wounds demonstrated an in vivo chemotactic response of macrophages and fibroblasts to both PDGF-BB and to TGF-beta 1 but the response to TGF-beta 1 was significantly less than that observed with PDGF-BB. Marked increases of procollagen type I were observed by immunohistochemical staining in fibroblasts in treated wounds during the first week. The augmented breaking strength of TGF-beta 1 was not observed 2 and 3 wk after wounding. However, the positive influence of PDGF-BB on wound breaking strength persisted through the 7 wk of testing. Furthermore, PDGF-BB-treated wounds had persistently increased numbers of fibroblasts and granulation tissue through day 21, whereas the enhanced cellular influx in TGF-beta 1-treated wounds was not detectable beyond day 7. Wound macrophages and fibroblasts from PDGF-BB-treated wounds contained sharply increased levels of immunohistochemically detectable intracellular TGF-beta. Furthermore, PDGF-BB in vitro induced a marked, time-dependent stimulation of TGF-beta mRNA levels in cultured normal rat kidney fibroblasts. The results suggest that TGF-beta transiently attracts fibroblasts into the wound and may stimulate collagen synthesis directly. In contrast, PDGF is a more potent chemoattractant for wound macrophages and fibroblasts and may stimulate these cells to express endogenous growth factors, including TGF-beta, which, in turn, directly stimulate new collagen synthesis and sustained enhancement of wound healing over a more prolonged period of time.

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Platelet-derived growth factor and transforming growth factor-beta enhance tissue repair activities by unique mechanisms.

The platelet-derived growth factor (PDGF) is shown to be chemotactic for monocytes and neutrophils. Maximum monocyte chemotaxis to PDGF is fully equal to that achieved with C5a and occurs at congruent to 20 ng/ml (congruent to 0.7 nM). Maximum neutrophil chemotaxis is congruent to 60% that achieved with C5A but occurs at congruent to 1 ng/ml (congruent to 32 pM). The chemotactic activity of PDGF is blocked by specific antisera to PDGF and by protamine sulfate, a competitive inhibitor of PDGF binding to cell surfaces. In contrast to PDGF, epidermal growth factor shows no chemotactic activity for inflammatory cells at 0.5-100 ng/ml. The high level of chemotactic activity of PDGF suggests that in addition to its role as a mitogen for smooth muscle cells and fibroblasts, PDGF may be involved in attracting inflammatory cells to sites of platelet release.

/pdf/chemotaxis-of-monocytes-and-neutrophils-to-platelet-derived-2hdiwx76am.pdf

Chemotaxis of monocytes and neutrophils to platelet-derived growth factor.

Elastin-derived peptides, produced by digesting human aortic elastin and bovine ligament elastin with human neutrophil elastase, were tested for chemotactic activity. At 100 micrograms protein/ml, elastin digests were nearly as active for monocytes as saturating amounts of complement-derived chemotactic activity. Neutrophils and alveolar macrophages showed less response to elastin peptidces than did monocytes. Fractionation of the digests by gel filtration chromatography disclosed that maximal chemotactic activity eluted in fractions corresponding to 14,000-20,000 mol wt containing most of the desmosine cross-links in the digests. Whole human serum and rabbit anti-elastin immunoglobulin inhibited the chemotactic activity. Purified desmosine also showed chemotactic activity for monocytes, maximal at 10 nM. These findings suggest that elastin-degradation products enriched in cross-linking regions recruit inflammatory cells in vivo and that elastin proteolysis, characteristic of emphysema, may be a signal for recruitment of mononuclear phagocytes into the lungs.

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Chemotactic activity of elastin-derived peptides.

Platelet factor 4 is shown to be a chemotactic protein for human polymorphonuclear leukocytes and monocytes at concentrations found in human serum and reached locally in injured tissue. The maximum chemotactic response to platelet factor 4 nearly equals that achieved with saturating concentrations of the chemotactic activity derived from the fifth component of human complement, C5. Cells desensitized to C5 chemotactic activity retain chemotactic responsiveness to platelet factor 4. Serum contains inhibitory capacity against the chemotactic activity associated with platelet factor 4. Our results suggest that the local release of platelet factor 4 may be an important stimulus attracting inflammatory cells to sites of blood vessel injury.

Platelet Factor 4 Is Chemotactic for Neutrophils and Monocytes

Recent studies have demonstrated that tropoelastin and elastin-derived peptides are chemotactic for fibroblasts and monocytes. To identify the chemotactic sites on elastin, we examined the chemotactic activity of Val-Gly-Val-Ala-Pro-Gly (VGVAPG), a repeating peptide in tropoelastin. We observed that VGVAPG was chemotactic for fibroblasts and monocytes, with optimal activity at approximately 10(-8) M, and that the chemotactic activity of VGVAPG was substantial (half or greater) relative to the maximum responses to other chemotactic factors such as platelet-derived growth factor for fibroblasts and formyl-methionyl-leucyl-phenylalanine for monocytes. The possibility that at least part of the chemotactic activity in tropoelastin and elastin peptides is contained in VGVAPG sequences was supported by the following: (a) polyclonal antibody to bovine elastin selectively blocked the fibroblast and monocyte chemotactic activity of both elastin-derived peptides and VGVAPG; (b) monocyte chemotaxis to VGVAPG was selectively blocked by preexposing the cells to elastin peptides; and (c) undifferentiated (nonelastin producing) bovine ligament fibroblasts, capable of chemotaxis to platelet-derived growth factor, did not show chemotactic responsiveness to either VGVAPG or elastin peptides until after matrix-induced differentiation and the onset of elastin synthesis. These studies suggest that small synthetic peptides may be able to reproduce the chemotactic activity associated with elastin-derived peptides and tropoelastin.

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Gail L. Griffin

Papers

Platelet-derived growth factor and transforming growth factor-beta enhance tissue repair activities by unique mechanisms.

Chemotaxis of monocytes and neutrophils to platelet-derived growth factor.

Chemotactic activity of elastin-derived peptides.

Platelet Factor 4 Is Chemotactic for Neutrophils and Monocytes

Val-Gly-Val-Ala-Pro-Gly, a repeating peptide in elastin, is chemotactic for fibroblasts and monocytes.