Antithrombin reduces mesenteric venular leukocyte interactions and small intestine injury in endotoxemic rats

We examined the hypothesis that recombinant human antithrombin would reduce mesenteric venule leukocyte adhesion and small intestine injury in endotoxemic rats. Endotoxemic (endotoxin 10 mg/kg, intravenously) rats were treated either with saline or recombinant human antithrombin (250 and 500 U/kg). In some rats, indomethacin (100 mg/kg, intraperitoneally) was injected 60 min prior to endotoxin and recominant human antithrombin (500 U/kg) treatment. Compared to controls, intravital videomicroscopy of the mesentric venule showed an increase of leukocyte rolling (55+/-17 versus 70+/-19 leukocytes/min; P < 0.05) and firm adhesion (1.1+/-0.3 versus 5.8+/-0.8 leukocytes/100 microm; P < 0.05) in endotoxemic rats. Recombinant human antithrombin attenuated endotoxin-induced venular endothelium leukocyte adhesive cascade. The beneficial effects of recombinant human antithrombin on leukocyte adhesion were inhibited by indomethacin (100 mg/kg, intraperitoneally) in endotoxemic rats. Endotoxin treatment increased fluorescein isothiocyanate (FITC)-labeled dextran 4,000 (FD4) gut lumen to plasma ratio and wet weight/dry weight ratio. Recombinant human antithrombin (500 U/kg) attenuated endotoxin-induced gut injury. These observations suggest that recombinant human antithrombin reduces endothelium-leukocyte interactions in endotoxemic rats by interacting with local prostacyclin production.

Clinical trial results with antithrombin III in sepsis

OBJECTIVE

To present and discuss the rationale and results of clinical trials using antithrombin (AT) supplementation in patients with sepsis.

DATA SOURCES/STUDY SELECTION

Review of all controlled (open or double-blind) studies of patients with severe sepsis or septic shock who were treated with AT concentrates to obtain better control of coagulation activation and inflammation.

DATA EXTRACTION

AT is a major inhibitor of the coagulation cascade. Recent experimental studies have also shown that it can modulate the inflammatory reactions that occur during sepsis. An early and prolonged decrease in AT activity is well documented during sepsis-induced disseminated intravascular coagulation and during the systemic inflammatory response. Thus, supplementation with AT concentrates has been proposed as a potential therapy in sepsis patients.

DATA SYNTHESIS

Numerous uncontrolled studies of AT supplementation in sepsis patients have been reported in the last 20 yrs. Since 1993, four placebo-controlled randomized studies have been performed in France, Germany, Northwestern Europe, and Italy. Three of these studies were subjected to a meta-analysis of 122 patients. Results showed a nonsignificant 22% reduction in the 30-day all-cause mortality and a reduction in the length of stay in the intensive care unit in the AT treated group. The Italian study of 120 patients demonstrated that the overall mortality was similar in the placebo and treated groups. However, post hoc analysis according to the Cox regression model showed that in patients with septic shock, AT supplementation significantly decreased the risk of death.

CONCLUSIONS

Together, these studies are consistent with the positive effect seen with AT supplementation in patients with severe sepsis. A multicenter phase III trial is currently in progress to definitively document its effect on mortality.

Effects of dental plaque antiseptic decontamination on bacterial colonization and nosocomial infections in critically ill patients

OBJECTIVES

To document in intensive care unit (ICU) patients the effect of dental plaque antiseptic decontamination on the occurrence of plaque colonization by aerobic nosocomial pathogens and nosocomial infections.

DESIGN

Single-blind randomized comparative study.

SETTING

A 16-bed adult intensive care unit in a university hospital.

PATIENTS

Patients consecutively admitted in the ICU with a medical condition suggesting an ICU stay of 5 days and requiring mechanical ventilation.

INTERVENTIONS

After randomization, the treated group received dental plaque decontamination with 0.2% chlorhexidine gel, three times a day during the ICU stay. The control group received standard oral care. SPECIFIC MEASUREMENTS: Dental status was assessed by the Caries-Absent-Occluded index; the amount of dental plaque was assessed by a semi-quantitative plaque index. Bacterial sampling of dental plaque, nasal and tracheal aspirate, blood, and urine cultures were done on days 0, 5, 10, and every week.

MAIN RESULTS

Sixty patients were included; 30 in the treated group and 30 in the control one (mean age: 51 +/- 16 years; mean Simplified Acute Physiological Score II: 35 +/- 14 points). On admission, no significant differences were found between both groups for all clinical and dental data. Compared with the control group, the nosocomial infection rate and the incidence densities related to risk exposition were significantly lower in the treated group (18 vs 33% days in the ICU and 10.7 vs 32.3% days of mechanical ventilation; P < 0.05). These results were consistent with a significant preventive effect of the antiseptic decontamination (Odds Ratio: 0.27; 95% CI: 0.09; 0.80) with a 53% relative risk reduction. There was a trend to a reduction of mortality, length of stay, and duration of mechanical ventilation.

CONCLUSIONS

An antiseptic decontamination of dental plaque with a 0.2% chlorhexidine gel decreases dental bacterial colonization, and may reduce the incidence of nosocomial infections in ICU patients submitted to mechanical ventilation.

Inflammation-induced systemic proteolysis of inter-alpha-inhibitor in plasma from patients with sepsis

Inter-alpha-inhibitor (IalphaI) is a human plasma serine proteinase inhibitor. It contains one light peptide chain called bikunin that exerts antiproteinase activity and other antiinflammatory functions. Bikunin is covalently linked to two heavy chains that, after tissular diffusion, stabilize the extracellular matrix. Owing to its negative acute-phase reactant character and its susceptibility to proteolysis, IalphaI has been implicated in the pathophysiology of sepsis. Moreover, IalphaI has been shown to exert a protective effect on a pig model of endotoxic shock. Twenty patients admitted to the intensive care unit (ICU) for a septic syndrome were included in the present study. IalphaI and antithrombin III (ATIII) levels were measured on admission. Sequential measurements of IalphaI could be done in 4 patients. We demonstrate that IalphaI levels are significantly decreased in plasma samples collected on admission from patients with sepsis (59 +/- 32 mg/L vs 241 +/- 70 mg/L; P < .0001). This decrease was greater in severe sepsis and septic shock than in sepsis. Death was not predictable from initiol IalphaI levels. In 2 patients with a favorable course, IalphaI values regularly increased during the ICU stay. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by immunoblot analysis and microsequencing, we characterized IalphaI-related components in plasma from several patients; they obviously arise from IalphaI through proteolytic cleavage. Thus, systemic proteolysis and decreased biosynthesis both contribute to the fall in the plasma level of IalphaI. Because IalphaI is very sensitive to proteolysis by polymorphonuclear granulocytes (PMNs) that are stimulated during sepsis, we suggest that IalphaI plasma level would be a useful marker for neutrophil proteinase activity. ATIII, as well as IalphaI, is considered a negative acute phase protein. Because in vitro ATIII is less susceptible than IalphaI to proteolysis by PMNs and because their relative levels weakly correlated, we suggest that an unspecific systemic proteolysis is not significantly involved in the ATIII deficiency occurring in sepsis.

Effects of a combined antithrombin III and protein C supplementation in porcine acute endotoxic shock

Antithrombin III (ATIII) and protein C (PC) are major inhibitors of the coagulation cascade and might regulate the cytokine network. We tested the possibility that a combined supplementation using these two inhibitors might have synergistic effects on sepsis-induced disseminated intravascular coagulation and shock. Hemodynamics, coagulation parameters, tumor necrosis factor (TNF) alpha, and interleukin 6 levels were measured in pigs submitted to a bolus infusion of Escherichia coli endotoxin (lipopolysaccharide). Four groups were studied: control lipopolysaccharide, ATIII (100 IU/kg), PC (50 IU/kg), and ATIII-PC (same doses). The endotoxin infusion resulted in a typical hypokinetic shock with disseminated intravascular coagulation in all animals. Compared with the control group, a significant improvement in mean arterial pressure and systemic vascular resistance was observed in the PC and ATIII-PC groups. The increase in lactate levels was almost completely blunted in the PC group. A significant lesser increase in TNFalpha levels was observed in the ATIII-PC group. No effects were seen on interleukin 6 levels. Coagulation and fibrinolysis parameters were not improved by ATIII and/or PC, except for a lesser decrease in prothrombin time in the ATIII-PC group. We conclude that in this acute endotoxic model, a combined supplementation using PC and ATIII concentrates has favorable effects on hemodynamic parameters and TNFalpha levels, independently from the anticoagulant actions of these inhibitors.

Effects of inter-alpha-inhibitor in experimental endotoxic shock and disseminated intravascular coagulation

We investigated the effects of human inter-alpha-inhibitor (I alpha I) on hemodynamics, oxygenation, and coagulation parameters in a porcine model of endotoxic shock. Four groups of six animals were studied: (1) control, (2) I alpha I group receiving 30 mg/kg I alpha I over 30 min, (3) LPS group receiving 5 micrograms.kg/min Escherichia coli endotoxin over 30 min, and (4) LPS + I alpha I group receiving 30 min after endotoxin 30 mg/kg/30 min I alpha I. We measured hemodynamic and oxygenation parameters, usual coagulation markers and plasma levels of thrombin-antithrombin complexes, antithrombin III activity, plasminogen activator tissue type, plasminogen activator inhibitor type 1, von Willebrand factor, tumor necrosis factor-alpha, and I alpha I at baseline and at 30, 60, 90, 120, 180, 240, and 300 min. In the I alpha I group, plasma I alpha I levels reached 447 +/- 23 mg/L just after injection and 287 +/- 39 mg/L at 300 min. I alpha I half-life was 7.3 +/- 1.9 h. In the IPS + I alpha I group, I alpha I plasma levels decreased more rapidly, reaching 260 mg/L at 300 min. Compared with the LPS group, administration of I alpha I normalized the mean arterial pressure and cardiac index, improved the LPS-induced pulmonary hypertension, and resulted in the blunted increase in blood lactate and oxygen extraction ratio. A significant decrease in thrombin-antithrombin complexes and plasminogen activator inhibitor type 1 levels were observed. There was no significant difference in plasma tumor necrosis factor-alpha levels. We concluded that in this hypodynamic model of endotoxin shock, I alpha I administration resulted in a marked improvement in the hemodynamic, oxygenation, and coagulation parameters.

Pig I alpha I appears unmodified in plasma in case of endotoxin-induced disseminated intravascular coagulation

The unrestricted activity of leukocyte proteinases is thought to contribute to the degradation of plasma proteins and thus amplify the coagulation disorders occurring in septic shock. Inter-alpha-inhibitor (I alpha I) is a plasma protein particularly susceptible to their action. Therefore we investigated its behavior in a porcine model of endotoxin shock which reproduces the coagulation changes observed in human sepsis. We did not detect any qualitative or quantitative modification of porcine I alpha I in plasmas collected from pigs after endotoxin infusion. To explain these data, I alpha I was incubated with polymorphonuclear neutrophils (PMN) stimulated by FMLP in the presence of cytochalasin B. We found that, unlike human PMN, porcine cells were unable to proteolyze I alpha I. Moreover, in the incubation medium of pig PMN, triggered either by FMLP or PMA, no measurable elastase activity was evidenced. Therefore, we urge to better take into account species differences in functional responses of PMN, to explain the experimental results obtained in animal models of septic shock.

Effects of N omega-nitro-L-arginine methyl ester on the endotoxin-induced disseminated intravascular coagulation in porcine septic shock

OBJECTIVES

Nitric oxide is known to prevent platelet aggregation and clot formation. Inhibitors of nitric oxide synthase might promote or enhance endotoxin disseminated intravascular coagulation. The present study was designed to evaluate the effects of the arginine analog, N omega-nitro-L-arginine methyl ester (L-NAME), on the endotoxin-induced disseminated intravascular coagulation in a porcine model of septic shock.

DESIGN

Prospective, comparative, experimental study.

SETTING

Laboratory at a large university hospital.

SUBJECTS

Sixteen female piglets, weighing 20 to 28 kg.

INTERVENTIONS

Three groups of animals were studied: a control group (n = 6); a lipopolysaccharide (LPS)-treated group (n = 5) receiving Escherichia coli endotoxin (5 micrograms/kg/min over 30 mins); and an LPS + L-NAME group (n = 5) receiving endotoxin and, 1 hr after, a bolus of L-NAME (25 mg/kg).

MEASUREMENTS AND MAIN RESULTS

Hemodynamic changes, usual coagulation parameters, and plasma concentrations of thrombin-antithrombin complexes, antithrombin III activity (At III), tissue plasminogen activator, plasminogen activator inhibitor type 1, and von Willebrand factor were measured at baseline, and at 30, 60, 90, 120, 180, 240, and 300 mins. After euthanasia or death, lungs and kidneys were withdrawn for histologic study. The extent of microvascular thrombosis was assessed by a semiquantitative disseminated intravascular coagulation score. In both septic endotoxin group, administration of LPS resulted in hemodynamic changes typical of severe septic shock, with disseminated intravascular coagulation and histologic changes characterized by adult respiratory distress syndrome and kidney microthrombosis. L-NAME administration normalized mean arterial pressure with a dramatic increase in systemic vascular resistances and a marked decrease in cardiac index. The changes in usual coagulation parameters, AT III, tissue plasminogen activator, and plasminogen-activator inhibitor type 1 concentrations were not different between both septic groups. However, in the LPS + L-NAME group, thrombin-antithrombin complexes and von Willebrand factor were higher and associated with a higher histologic disseminated intravascular coagulation score.

CONCLUSION

In this model of endotoxin septic shock, L-NAME administration resulted in histologic and coagulation changes consistent with an increased activation of intravascular coagulation.

Coagulation inhibitor substitution during sepsis

This review presents the rationale for and main results of coagulation inhibitor substitution during experimental and human sepsis. Activation of the contact system induces activation of the classical complement pathway with generation of anaphylatoxins, of the kinins pathway and of fibrinolysis. Physiologic inhibition depends on the C1-inhibitor (C1-Inh.). Septic patients exhibit a relative deficiency of biologically active C1-Inh. Substitution with concentrations of C1-Inh has been safely performed and preliminary results are consistent with a possible beneficial effect on hypotension and vasopressor requirement in septic shock. The extrinsic pathway is the main initial coagulation process involved in sepsis-induced DIC. Endothelial and monocyte generation of tissue factor (TF) is activated by bacterial products and endotoxin. Activation of TF is counteracted by a specific tissue factor pathway inhibitor (TFPI). The potential for TFPI substitution to inhibit the activation of the coagulation cascade in sepsis requires further study. Thrombin generation is inhibited by antithrombin III (AT III) and the protein C-protein S system. During sepsis, AT III is consumed and degraded by elastase. Animal studies have shown that DIC and death were prevented by high doses of AT III concentrates. Although a significant reduction in the duration of biological symptoms of DIC has been reported in most human studies, the usefulness of AT III substitution in human sepsis is still debated. None of the studies was able to document a statistically significant reduction in mortality. Protein C is activated by thrombomodulin and, with its cofactor protein S, inhibits factors Va and VIIIa. The free level of protein S depends on the level of the C4b binding protein (C4bBP), an acute-phase complement regulatory protein. During sepsis, protein C activity is significantly reduced, either by acute consumption or by thrombomodulin down-regulation, and increased levels of plasma C4bBP inhibit protein S. Infusion of activated protein C and protein S substitution both protect animals from the lethal effects of bacteria. Combining these different coagulation inhibitors should be carefully studied before its use in septic patients is recommended.

Sex steroid hormones in circulatory shock, sepsis syndrome, and septic shock

METHODS

Estrone (E1), estradiol (E2), testosterone (T), FSH, and LH levels were daily measured during a ten day period in 50 critically ill patients (38 men, 12 post-menopausal women). Patients were separated into four groups: A) no circulatory failure, no sepsis, B) sepsis syndrome without circulatory failure, C) circulatory failure without sepsis syndrome, D) septic shock. Results of hormonal measurements were compared 1) among the 4 groups, 2) between male and female patients, 3) between septic and nonseptic patients. The potential for the infusion of the vasoactive drug dobutamine to induce sex hormonal changes was documented in ten additional septic shock patients by measuring cortisol, E1, and T at base-line and after dobutamine infusion. Changes in active renin and plasma renin activity (PRA) were used as indirect witness of the dobutamine-induced beta 2-stimulation.

RESULTS

A dramatic increase in E1 and E2 levels was observed in women of groups B and D, and only in male patients of group D. In the septic patients, estrogen levels peaked at days 1 and 2 and trended to normal from day 6 after the onset of sepsis, while FSH and LH decreased. No difference was found between survivors and non-survivors. Whatever the group, male patients had low T levels throughout the study. Dobutamine induced a significant increase in active renin levels and a decrease in the regression slope between renin and PRA. Cortisol levels remained normal. No significant change in E1 and T was observed after dobutamine.

CONCLUSIONS

High estrogen levels were specifically observed in patients with sepsis and septic shock, either males or females. Decreased LH and FSH levels were consistent with the negative feed-back effect of high estrogen levels on pituitary secretion. Circulating T levels were decreased in all male patients. We found no correlation between sequential estrogen levels and outcome. These levels were not modified by a dobutamine-induced beta-2 stimulation.

Glucocorticoid inhibition of Na-Pi cotransport in renal epithelial cells is mediated by protein kinase C

The effect and mechanism of action of glucocorticoids (GC) on Na-Pi cotransport were evaluated in opossum kidney cells. Dexamethasone (1-1000 nM) inhibited sodium-dependent Pi uptake in a time- and concentration-dependent manner. Inhibition was maximal after a 6-h incubation with dexamethasone and was prevented by cycloheximide and actinomycin D. The effect was related to a 37% decrease of the Vmax value after incubation with 100 nM dexamethasone. The effect of dexamethasone was mimicked by cortisol and blocked by GC receptor antagonists RU38486 and progesterone. GC affected neither glucose or alanine uptake nor Na/H exchange activity. Inhibition of Pi uptake persisted when Na/H was blocked by amiloride or dimethylamiloride. GC had no effect on basal or parathyroid hormone- and forskolin-stimulated intracellular cAMP content. Dexamethasone and extracellular cAMP, parathyroid hormone, or 3-isobutyl-1-methylxanthine had additive inhibitory effects on Pi uptake. Staurosporine, GF109203X, or calphostin C (three dissimilar inhibitors of protein kinase C (PKC)) and PKC down-regulation blunted the inhibitory effect of glucocorticoids on Pi uptake. GC increased both membrane-bound PKC activity and the membrane/cytosol PKC activity ratio. This is the first report of GC activation of PKC in renal cells, which appears to mediate the steroid inhibitory effect on Pi transport.

Modulation of Na-H exchange activity by angiotensin II in opossum kidney cells

Angiotensin II (ANG II) was shown to modulate transport in the renal proximal tubule through both inhibition of adenylate cyclase and protein kinase C (PKC) activation. We evaluated the effects of ANG II on adenosine 3',5'-cyclic monophosphate (cAMP) content and Na-H exchange activity (amiloride-sensitive Na influx) in two strains of opossum kidney (OK) cells originating from different sources, OK-VD and OK-RR cells. In OK-VD cells, ANG II inhibited basal and parathyroid hormone (PTH)-induced cAMP generation in a pertussis toxin-sensitive manner and reversed PTH inhibition of Na-H exchange. These effects of ANG II were prevented by PD 123319, a selective nonpeptide antagonist of AT2 receptors. In contrast, DuP 753, which antagonizes selectively AT1 receptors, had no effect. In OK-RR cells, ANG II had no effect on cAMP content and decreased Na-H exchange activity. The effect of ANG II persisted in the presence of PTH but was abolished by PKC downregulation and by DuP 753, but not by PD 123319. In conclusion, two types of ANG II receptors, coupled to distinct signaling pathways, were expressed independently in OK cells originating from two different sources and mediated opposite effects of ANG II on Na-H exchange activity. Those models provide a powerful tool for studying the intracellular steps involved in the tubular effects of ANG II and to evaluate the effect of pharmacological inhibitors of ANG II binding to its receptors.

Postexercise proteinuria in rowers

Exercise performance, glomerular filtration rate (GFR), and urinary filtration of proteins during static pool rowing and cycling to exhaustion were studied in trained rowers. The peak VO2 and heart rate were higher during rowing than during cycling. There was a reduction in plasma volume and an increase in lactate concentration after exercise; however, no significant difference was noted between rowing and cycling in either case. Postexercise proteinuria was increased 8 and 11 times, and albuminuria 25 and 20 times after rowing and cycling exercises, respectively. There was no difference between these exercises in terms of protein or albumin excretion. There was no change in postexercise GFR. Albumin clearance was increased 18 and 20 fold after rowing and cycling, respectively. A significant, but low correlation, r = 0.56, was noted between albumin excretion and postexercise blood lactate concentration. Thus, no difference in the effect on kidney response was found between static pool rowing and cycling to exhaustion in these athletes.

[Multiple tumors in endometrial cancer]

Out of 1220 (100%) cases of endometrial carcinomas, registered at the Klinik Bad Trissl during a period of 20 years (1968-1988), over 127 cases (10.4%) of double and triple malignomas were found. 86 cases (7.0%) are correlated with a second primary breast cancer, 41 (3.4%) with other primary malignomas. 14 cases (1.1%) show triple malignomas. 8 precancerous cases (0.7%) were included in the survey. Contrary to medical literature the survey reveals a different distribution of neoplasms among the affected organs. Four fifths of the tumour combinations were located in the female genital tract including the breast. Therefore the early detection of potential secondary malignomas should be included in the aftercare of endometrial cancer.

[The value of skeletal scintigraphy in the aftercare of breast carcinoma. A prospective study of 750 cases]

In 1987/88 a prospective study was undertaken of 750 patients with postoperative carcinoma of the breast but no evidence as yet of skeletal metastases. A thorough history regarding pain was taken with pre-set questions and an exact clinical examination conducted to reveal any skeletal pain. Subsequently whole-body skeletal scanning was performed, plus additional X-ray films, determination of tumour markers CA-15-3 and CEA, and further tests as indicated. Clinical and imaging results agreed in 649 patients. In 70 patients the clinical suspicion or questionable finding of metastases was not confirmed by radiology or a scan. Bone metastases would have been missed in only 14 patients (1.9%) without a skeletal scan. Eleven of these 14 patients were in high-risk groups (negative hormone receptor status; axillary lymph node metastases). Skeletal metastases were undiscovered in only three of the 750 patients (0.4%). It is thus sufficient to limit skeletal scans to high-risk groups, as long as a careful history of pain is taken and a thorough clinical examination conducted.