Drug – bio-affecting and body treating compositions – Designated organic active ingredient containing – Having -c- – wherein x is chalcogen – bonded directly to...
Reexamination Certificate
1994-12-12
2003-10-28
Criares, Theodore J. (Department: 1617)
Drug, bio-affecting and body treating compositions
Designated organic active ingredient containing
Having -c-, wherein x is chalcogen, bonded directly to...
C514S265100, C514S266400
Reexamination Certificate
active
06638938
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The present invention provides a method for preventing tissue injury caused by tissue hypoxia, comprising administering a compound that inhibits signal transduction by inhibiting cellular accumulation of a linoleate-containing phosphatidic acid (PA) through an inhibition of the enzyme LPAAT (lysophosphatidic acyltransferase).
BACKGROUND OF THE INVENTION
Acute lung injury, manifested clinically as the Adult Respiratory Distress Syndrome (ARDS) occurs in more than 50% of patients following severe injury and blood loss. ARDS is characterized clinically by decreasing lung compliance and severe impairment of oxygen diffusion (Hammerschmidt et al.,
Lancet
1:947, 1980; Moore et al.,
J. Trauma
31:629, 1991; Pepe et al.,
Am. J. Surg
. 144:124, 1982; and Baker et al.,
Am. J. Surg
. 140:144, 1980). Histologic changes in the lungs which are present in this setting include neutrophil and mononuclear infiltrates, interstitial edema, intraaveolar hemorrhage, and fibrin formation. In injured patients, increased plasma levels of proinflammatory cytokines, such as IL-6 and IL-8, as well as evidence of endothelial activation, as shown by elevated circulating titers of soluble intracellular adhesion molecules (sICAM), are found within one hour of blood loss and trauma. Bronchoalveolar lavages obtained from patients with ARDS contain elevated titers of IL-1&bgr; and TNF&agr;. Also, release of proinflammatory cytokines, such as IL-1 and TNF&agr; is increased after blood loss (Abraham et al.,
Circ. Shock
25:33, 1988; Meldrum et al.,
J. Surg. Res
. 51:158, 1991; and Ertel et al.,
Immunology
74:290, 1991). Studies examining the 4 hour period immediately following hemorrhage demonstrated increased levels of mRNA for proinflammatory cytokines, including IL-1&agr;, IL-1&bgr;, TNF&agr;, IL-6 and IFN-&ggr;, among cells isolated from mucosal sites (e.g., lungs and intestines) but not among splenocytes or peripheral blood mononuclear cells (Shenkar and Abraham,
Lymphokine Cytokine Res
. 12:237, 1993). It has been postulated that increased local production of proinflammatory cytokines may contribute to lung injury in this setting. Blood loss is a central factor in the pathophysiologic instability that follows trauma, and has been associated with alterations in macrophage, T cell and B cell function. Hemorrhage does not result in changes in absolute or relative numbers of T cell or B cell subsets in the spleen, lymph nodes, blood or iung (Abraham and Freitas,
J. Immunol
. 142:899, 1989; Robinson and Abraham,
J. Immunol
. 145:3734, 1990; Abraham et al.
Cell. Immunol
. 122:208, 1989; and Robinson et al.,
Clin. Exp. Immunol
. 88:124, 1992).
It is possible that the local ischermia and/or hypoxia created by redistribution of blood flow in visceral (splanchnic) organs such as the gut (particularly the small intestine) and kidney are responsible for induction of the cytokine cascades, which in turn, result in distal organ injury. Evidence exists demonstrating that absolute and relative blood flow levels within these organs fall within minutes of volume shifts, hemorrhage, or induction of other causes of shock (textbook Hypertension). There is, therefore, a need in the art for compounds which (1) prevent initial production of proinflammatory cytokine mediators in response to decreased perfusion and (2) prevent redistribution of microcirculation induced by these proinflammatory cytokine mediators.
In severely injured patients, serum levels of IL-6 and IL-8 are increased within one hour or injury, but do not appear to predict which patients will develop ARDS (Hoch et al.,
Crit. Care Med
. 21:839, 1993). No detectable IL-1&agr;, IL-1&bgr;, orendotoxin was found in patient samples obtained over 5 days post-injury in these patients (Hoch et al., infra.). Moreover, plasma levels of TNF are rarely increased following severe injury and there does not appear to be any correlation between the presence or amount of TNF&agr; and the development of ARDS or organ system dysfunction.
Based upon experiments ongoing which examine the biochemical events following severe injury with blood loss and resulting tissue hypoxia, even if treated medicinally with fluids and/or blood products still results in inflammatory changes in the lungs and other organs.
Neutrophils are important for host-defense against bacterial and other infections. This is suggested as a consequence of observations that there is an increased infections seen in patients with insufficient numbers of neutrophils or with neutrophils with genetically determined abnormalities (e.g., chronic granulomatous disease). Antibiotics are available to treat infections (i.e., be directly cytotoxic to the infectious agent), but there are no specific therapies available to treat septic shock or the compounding organ dysfunction that follows from septic shock or other causes of tissue hypoxia/ischemia. Therefore it may be necessary to risk decreasing neutrophil function (as direct cytotoxic agents against the pathogen) to prevent fatal lung injury and other organ dysfunction.
Cystic fibrosis (CF) is a lethal hereditary disorder caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The CFTR gene product is a 168 kD glycosylated membrane protein that functions as a chloride channel regulated by cytoplasmic protein kinases (Riordan et al.,
Science
245:1066, 1989). Although the link between mutations in the CFTR gene and the pathogenesis of CF are not understood, the lethal clinical manifestations of CF are related to a thick, infected mucus and chronic neutrophil-dominated inflammation of the epithelial surface of the airways. A large number of neutrophils place the airway epithelium in jeopardy consequent to exposure to potent neutrophil mediators, including neutrophil elastase (NE), and reactive oxygen species, and a variety of cytokines (Sibille and Reynolds,
Am. Rev. Respir. Dis
. 141:471, 1990; and McElvaney et al.,
Lancet
337:392, 1991). Although critical to host defense, neutrophils cause progressive damage to airway epithelium by virtue of their potent mediators, most significantly NE. Not only can NE damage epithelial cells by direct proteolytic effects, but it can also hinder host defense by interfering with ciliary clearance, increasing mucus production, cleaving immunoglobutin and complement, and by impairing phagocytosis and killing of
Pseudomonas aeruginosa
by neutrophils. The fluid lining the respiratory epithelium in CF contains large numbers of activated neutrophils and active NE, and the NE in CF is capable of inducing bronchial epithelium cells to express the gene for IL-8 and release neutrophil chemotactic activity as properties of IL-8 (Nakamura et al.,
J. Clin. Invest
. 89:1478, 1992). Neutrophils in the thick mucus are rendered hypoxic. Therefore there is a need in the art to find a therapeutic compound capable of inhibiting IL-8 signaling and thereby provide treatment for CF.
Hypoxic injury generates oxidative injury. For example, serum antioxidants may be predictors of ARDS in sepsis patients. At an initial diagnosis of sepsis (6-24 hr before development of ARDS), serum manganese superoxide dismutase concentration and catalase activity were higher is a study of patients (6) who subsequently developed ARDS as compared to patients (20) who did not develop ARDS (Leff et al.,
Lancet
341:777, 1993). Accelerated intravascular generation of oxygen radicals from stimulated neutrophils, circulating xanthine oxidase, and other sources have been implicated in the pathogenesis of sepsis and ARDS (Repine,
Lancet
339:466, 1992). Moreover, in vitro, exposure to decreasing oxygen tensions progressively increased xanthine dehydrogenase (XD) and xanthine oxidase (XO) activities over 48 hr in cultured pulmonary artery endothelial cells without altering XD/XO ratios. Oxygen tension negatively modulates XO and its precursor XD, and was associated with an increase in release O
2
−
(Terada et al.,
Proc. Natl. Acad. Sci. USA
89:3362, 1992). This connection to hypoxia and multiple o
Bursten Stuart L.
Rice Glenn C.
Singer Jack W.
Cell Therapeutics Inc.
Criares Theodore J.
Foley & Lardner
LandOfFree
Method for preventing tissue injury from hypoxia does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for preventing tissue injury from hypoxia, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for preventing tissue injury from hypoxia will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3115510