Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Platelet-bacterial interactions were examined in vitro by incubating organisms isolated from patients with septicemia with normal platelet-rich plasma. The potency of various species of gram-positive and gram-negative bacteria to induce irreversible platelet aggregation was then determined in an aggregometer. The aggregation curves produced by the bacteria resembled the normal platelet response to collagen and were impeded by the presence of aspirin. Strains of Staphylococcus aureus and Pseudomonas aeruginosa isolated from 25 different patients produced maximum increases in light transmission and irreversible platelet aggregation with relatively rapid mean aggregation times; six of these patients had clinical and laboratory evidence of disseminated intravascular coagulation. In contrast, isolates of alpha streptococcus and Staphylococcus epidermidis induced irreversible platelet aggregation much less commonly and were associated with considerably longer mean aggregation times. None of the latter group of patients had evidence of disseminated intravascular coagulation. Isolates of bacteria from a small number of patients with subacute bacterial endocarditis uniformly induced irreversible platelet aggregation. Addition of paired bacterial isolates to normal platelet-rich plasma demonstrated a synergistic aggregation response. These data suggest that a relative hierarchy exists in bacterial strain potency to induce irreversible platelet aggregation. The rapidity and degree of aggregation in vitro correlated well with the clinical and laboratory evidence for subacute bacterial endocarditis and disseminated intravascular coagulation in vivo. These observations may provide useful adjunctive laboratory information to help establish the diagnosis of subacute bacterial endocarditis, especially in the clinical setting where the classical findings of endocarditis are not obvious during initial presentation.
 ...
PMID:In vitro correlation of platelet aggregation with occurrence of disseminated intravascular coagulation and subacute bacterial endocarditis. 310 30

Septic surgical patients often require fluid administration to maintain cardiovascular stability due, in part, to the sepsis-induced increase in vascular permeability and associated plasma volume depletion. Plasma fibronectin deficiency exists in such septic patients. We determined if maintenance of fibronectin levels by administration of fibronectin-rich human plasma cryoprecipitate would lower the resuscitative fluid volume needed for support of arterial pressure in septic postoperative sheep which were experimentally depleted of plasma fibronectin. Following a 2-hr postoperative baseline period, denatured collagen (gelatin, 8.7 mg/kg), which has a high affinity for fibronectin, was infused into both control and experimental sheep in order to acutely deplete plasma fibronectin. Sheep were then challenged both intraperitoneally and intravenously with live Pseudomonas (5 x 10(10) bacteria IP; 5 x 10(9) bacteria IV). Experimentals were given fresh plasma cryoprecipitate intravenously at a dose of 4 units bolus, followed by 3 units/hr for 5 hr. Controls received plasma cryoprecipitate selectively depleted of fibronectin by affinity chromatography. Bacterial challenge rapidly resulted in severe systemic hypotension. Ringer's lactate was infused intravenously into both groups at a rate sufficient to maintain a systemic arterial pressure of approximately 50 mm Hg with a maximum pulmonary artery wedge pressure of 15-18 mm Hg. Its rate of infusion was periodically adjusted to maintain this hemodynamic status. Comparison was made of the volume of Ringer's lactate required to maintain an arterial pressure of 50 mm Hg in both groups. Net fluid requirement was significantly (p less than 0.05) less in postoperative septic sheep (47.4 +/- 6.2 mg/kg/hr) treated with fibronectin-rich cryoprecipitate compared to the fluid requirement (71.7 +/- 4.7 mg/kg/hr) for postoperative septic sheep receiving fibronectin-deficient cryoprecipitate. Thus elevation of plasma fibronectin concentration lowers the fluid requirements needed for hemodynamic support in postoperative Gram-negative sepsis.
 ...
PMID:Effect of fibronectin-rich human cryoprecipitate on fluid volume requirements in sheep during postoperative sepsis. 313 Apr 90

Immunoreactive plasma fibronectin depletion has been associated with the presence of collagen-fibronectin complexes in patients after trauma and in animal models of traumatic and burn injuries. However, the role of plasma fibronectin in the development of sepsis after traumatic and burn injuries in patients is unknown. Treatment of patients and animals with purified human plasma fibronectin ameliorates some of the clinical and metabolic effects of systemic endotoxemia. We report that the induction of immunoreactive plasma fibronectin deficiency by gelatin infusion is associated with enhanced effects of intraperitoneal Escherichia coli endotoxin injection. We have observed a significant increase in the concentrations of ammonia in plasma of treated rats compared with those in control rats administered the same dose of endotoxin.
 ...
PMID:Enhanced endotoxin effects in plasma fibronectin-deficient rats. 329 66

Clinical studies of ARDS have been successful in determining the most common predisposing clinical disorders and the natural history of this syndrome. Sepsis, gastric aspiration, and major trauma are the most frequently associated high-risk factors. Overall mortality is in the range of 60% to 70%, but is even higher if ARDS is associated with sepsis, severe acidemia, or decreased renal function. It is evident that multisystem failure is responsible for death in many patients, as well as secondary pulmonary and extrapulmonary infections. Pathologic studies have provided descriptive information regarding the acute, subacute, and chronic phases of the syndrome, but little insight into the precise pathogenesis of the initial lung injury or the progressive fibrosing alveolitis and lung destruction that develops in some patients. There has been considerable circumstantial evidence from clinical studies implicating the neutrophil as a potentially important mediator of the early changes in lung endothelial and epithelial permeability. However, not all investigators have found the same alterations in neutrophil function in the circulation or in the lavage from the lungs of patients with ARDS. Also, the heterogeneous etiologies of ARDS make it difficult to be sure that there is a final common pathway for acute lung injury in all ARDS patients. In addition, there are a host of mediators, including products of complement activation and arachidonic acid metabolism, that may be important in amplifying the inflammatory response. Also, abnormalities of surfactant production and collagen turnover, as well as impaired host defenses in the lung, may contribute to the progressive respiratory failure that occurs in some ARDS patients, even though the acute, exudative phase of lung injury has resolved. Future human studies may provide useful information about the mechanisms of the acute lung injury through studies of circulating plasma markers, blood elements, and lavage fluids from high-risk patients. On the other hand, samples of cells and mediators from the airspaces with lavage still may not reflect the critical interactions of mediators and cells with the lung endothelium that lead to the protein-rich pulmonary edema that characterizes the first phase of ARDS. Thus, experimental studies must continue to study the details of the early phases of acute lung injury (see article by Flick, page 455). Finally, it is clear that treatment designed to reduce the severity and the incidence of ARDS must be started early, since the syndrome develops so rapidly in high-risk patients.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Pathophysiology of the adult respiratory distress syndrome. What have we learned from human studies? 333 57

The high in-hospital mortality of ARDS has not diminished over the past 10 years, despite improvements in supportive intensive care. Much of the mortality arises from infections, particularly sepsis and pneumonia, and from organ failure, especially kidney failure. The rapid advances in understanding the interlocking pathophysiologic mechanisms of ARDS have not yet been translated into therapeutic trials of new methods for diminishing the injury or for stimulating normal repair. In part, this is because it is difficult to predict which high-risk patients will develop ARDS and then intervene early in the injury process. Patients in whom the risk for ARDS is extremely high have a very high mortality even without ARDS, thereby making efficacy of an early or prophylactic therapy quite difficult to prove. In spite of severe pathologic abnormalities, including fibrosis, early in the course of ARDS, most survivors return to almost normal pulmonary function. The few cases that have been studied with serial biopsies demonstrate resolution of fibrosis. This amazing recovery poses many fascinating questions about how the lung repairs itself. Given the heterogeneous causes of ARDS and the large number of structural, cellular, and biochemical abnormalities described, one can postulate that any one of numerous factors is important in normal repair. Most promising of these are the degree of basement membrane damage, the control of type II cell proliferation and differentiation, the control of collagen synthesis, the anatomic localization of fibrosis, and the control of collagenase action. These interactions of epithelial and mesenchymal tissues probably recreate the process of lung development in the injured adult lung. At a clinical level, the role of oxygen toxicity remains a significant issue. Oxygen acting as an oxidant may be partially responsible for the small airways disease seen in approximately one quarter to one third of survivors. The mortality data stress the need for better ways of preventing and diagnosing lung infections. Better definition of the clinical factors that put survivors at risk for persistent loss of lung function is also needed, and could define a subgroup in which trials of agents designed to improve repair would be most worthwhile. More information about the long-term pathologic course, though difficult to obtain, would also be very important. Perhaps some registry of ARDS survivors would permit closer follow-up and make available more late autopsy pathology when these people die of other causes. The rapid time course of ARDS provides an ideal testing ground for agents designed to either decrease lung injury or stimulate repair.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Pulmonary sequelae and lung repair in survivors of the adult respiratory distress syndrome. 333 67

Ultrastructural studies of the cartilaginous articular surfaces of human and rabbit joints have shown that cartilage is the target substratum for adhesion by Staphylococcus aureus, leading to intra-articular sepsis. Transmission and scanning electron microscope studies demonstrated bacteria in intimate contact with acellular cartilage matrix surfaces, particularly with collagen fibres. Certain strains of Staphylococcus aureus used in these experiments reveal a high binding capacity to collagen that is derived from a cartilage matrix. These studies indicate that the pathogenesis of intra-articular sepsis is based on the ability of certain strains of staphylococci to bind preferentially to a cartilage matrix.
 ...
PMID:Staphylococcal adhesion to collagen in intra-articular sepsis. 334 17

Concentric joint space narrowing of the hip is an expected radiographic finding in cases of inflammatory arthritis such as rheumatoid arthritis or sepsis. However, similar joint space narrowing is associated with chronic hemorrhagic conditions that produce hemosiderotic synovitis. Hemosiderotic synovitis results from chronic intra-articular bleeding such as occurs in pigmented villonodular synovitis, generalized bleeding diathesis, synovial hemangioma, and chronic trauma. Five hips in five patients with concentric joint space narrowing not associated with inflammatory arthritis or with hemophilia were reviewed clinically, radiographically, and pathologically. All patients had a hemosiderotic synovitis. The definitive diagnosis of pigmented villonodular synovitis was made pathologically in two cases that demonstrated nodular areas of giant cell proliferation, collagen production, and lipid-laden histiocytes on histologic samples.
 ...
PMID:Concentric joint space narrowing of the hip associated with hemosiderotic synovitis (HS) including pigmented villonodular synovitis (PVNS). 335 35

We evaluated the concept that the vascular entrance of both bacterial and nonbacterial particulate material could lead to hepatic parenchymal cell injury, either due to postphagocytic Kupffer cell activity or the margination of activated leukocytes in the liver. Injection of denatured, collagen-coated particles as well as heat-killed bacteria were used as particulate challenges. Hepatic parenchymal cell injury in vivo during postoperative sepsis was evaluated by plasma aspartate aminotransferase (AST) and ornithine carbamyl transferase (OCT) enzyme levels over 3-72 h. AST and OCT levels elevated following either laparotomy plus cecal ligation (mild sepsis) or laparotomy plus cecal ligation with puncture (severe sepsis), with the peak level at 24 h. In addition, the direct intravenous injection of either nonbacterial foreign particles or heat-killed Pseudomonas aeruginosa into normal rats also produced a dose-dependent elevation of AST and OCT. The plasma level of either AST or OCT actually increased 350-400% after injection of the non-bacterial particles. A similar dose related elevation in enzymes followed the intravenous injection of heat-killed Pseudomonas. To differentiate the potential contribution of activated hepatic Kupffer cells versus activated marginated neutrophils to the in vivo hepatic injury, we determined the release of the hepatic specific enzyme OCT by cultured hepatic parenchymal cells when they were exposed to isolated Kupffer cells or isolated PMNs that were activated by exposure to dead bacteria. Bacteria alone when added to cultured hepatocytes did not induce significant OCT release. In contrast, activated PMNs but not Kupffer cells induced a significant (p less than 0.05) release of OCT from parenchymal cells into the culture media. Thus, in vivo transient hepatic parenchymal cell injury with post-operative sepsis may be mediated by the margination of activated PMNs in the liver.
 ...
PMID:Hepatocyte injury during post-operative sepsis: activated neutrophils as potential mediators. 342 80

Cultured endothelial cells phagocytize Staphylococcus aureus, but the resultant effects are unknown. Monolayers of cultured bovine endothelial cells with or without [3H]adenine label were exposed to 100, 10, or 1 S. aureus organism per endothelial cell for 3.5 h. Lysostaphin was then applied to all cultures to destroy extracellular but not phagocytized S. aureus. In cultures treated for only 20 min with lysostaphin, S. aureus multiplied exponentially after a 9- to 12-h lag period. In cultures treated continuously with lysostaphin, numbers of S. aureus remained constant or decreased. These results indicate that S. aureus became extracellular and multiplied but did not multiply intracellularly. In parallel experiments, the release of 3H-adenine from prelabeled endothelial cell monolayers was assayed to indicate cytotoxicity. Results indicated that the loss of 3H-adenine from endothelial cell monolayers depended on the following: (i) the size of the S. aureus inoculum, (ii) the strain of S. aureus, and (iii) the length of time after exposure to S. aureus. S. aureus endocarditis and persistent septicemia could arise, at least in part, from ingestion of S. aureus by host endothelium. The intracellular location would afford S. aureus protection from host defenses and antibiotics. Eventual damage to endothelial cells could expose collagen, thus resulting in platelet adherence and vegetation formation. Intracellular S. aureus would be continuously released into the circulation, possibly accounting for the persistent bacteremia that is found in S. aureus endovascular infections.
 ...
PMID:Ingestion of Staphylococcus aureus by bovine endothelial cells results in time- and inoculum-dependent damage to endothelial cell monolayers. 362 96

In rats a standardized left colonic resection was performed and colonic continuity restored by an end-to-end anastomosis in one layer. The rats were subjected to an LD50 septic challenge by intraperitoneal injection of live Escherichia coli pre- or postoperatively. Controls received saline in a corresponding manner. Groups of animals were sacrificed on the 3rd or 7th postoperative day. The breaking strengths of the anastomosis and of the skin wound were measured. The collagen content of the anastomotic segments was analyzed. There were no differences in anastomotic or skin wound strength between septic animals and controls. Collagen content was unaffected. Wound healing was not influenced by sepsis in this model.
 ...
PMID:Influence of intraperitoneal Escherichia coli with septicemia on the healing of colonic anastomoses and skin wounds. An experimental study in the rat. 388 40


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>