Treatment and prophylaxis of severe infections in neutropenic patients by granulocyte transfusions

Bacterial and fungal infections are the main cause of morbidity and mortality in neutropenic patients. To resolve infections, an adequate number of functional granulocytes is required. Successful treatment of severe infections with granulocyte transfusions is strongly dependent on an adequate number of transfused cells. In this study, 42 neutropenic patients received rhG-CSF-stimulated granulocyte transfusions (GTXs). Of these patients, 18 with severe infections during neutropenia and 8 in a high-risk situation, as defined by severe infections during previous periods of neutropenia or increasing infectious parameters during prolonged neutropenia, received a median of three GTXs (range 1-25), containing a median total of 2.62x10(10) leukocytes (range 0.3-8.61x10(10)). A further 16 patients in a pilot study received prophylactic GTX, consisting of a median of three GTXs (range 1-4) containing a median total of 3.20x10(10) leukocytes (range 0.73-8.51x10(10)). Out of 18 patients with severe infections, 12 improved clinically or showed a resolution of infection after GTX. All 8 patients in a high-risk situation showed a stable clinical course without serious infections. Prophylactic GTX did not result in significant differences with regard to infectious parameters. The median number of transfused platelet units during the course of cytopenia was significantly reduced (13.5 units vs 22.0 units, P<0.02) compared to the control group. For the treatment of infections during neutropenia, rhG-CSF-stimulated granulocyte transfusions are safe and a promising approach.

Ascorbic acid for amelioration of reperfusion injury in a lung autotransplantation model in sheep

BACKGROUND

Reperfusion injury is the leading cause of early graft dysfunction after lung transplantation. Activation of neutrophilic granulocytes with generation of free oxygen radicals appears to play a key role in this process. The efficacy of ascorbic acid as an antioxidant in the amelioration of reperfusion injury after lung transplantation has not been studied yet.

METHODS

An in situ autotransplantation model in sheep is presented. The left lung was flushed (Euro-Collins solution) and reperfused; after 2 hours of cold storage, the right hilus was then clamped (group R [reference], n = 6). Group AA animals (n = 6) were treated with 1 g/kg ascorbic acid before reperfusion. Controls (group C, n = 6) underwent hilar preparation and instrumentation only.

RESULTS

In group R, arterio-alveolar oxygen difference (AaDO2) and pulmonary vascular resistance (PVR) were significantly elevated after reperfusion. Five of 6 animals developed frank alveolar edema. All biochemical parameters showed significant PMN activation. In group AA, AaDO2, PVR, work of breathing, and the level of PMN activation were significantly lower.

CONCLUSIONS

The experimental model reproduces all aspects of lung reperfusion injury reliably. Ascorbic acid was able to weaken reperfusion injury in this experimental setup.

Production of stem-cell transplants according to good manufacturing practice

Peripheral blood stem cells (PBSCs) are used for transplantation to reconstitute the hematopoietic system after high-dose chemotherapy. They are harvested from peripheral blood after mobilization by cytokines and/or chemotherapy. Further ex vivo manipulation steps (e.g., selection of CD34+ PBSCs, purging, expansion, and differentiation or gene transfer) can be performed. In 1997, more than 12,000 PBSC preparations were transplanted in Europe and the total number is steadily increasing [1]. To ensure quality and safety of the final cell products intended for clinical use, national and international guidelines and regulations have been issued. The implementation of a quality assurance (QA) program including the principles of good manufacturing practice (GMP) and a quality control system is a major requirement. GMP regulations apply to all phases of cell collection, processing, and storage, and to documentation, training of personnel, and equipment of the cell processing laboratory. They have to be followed by pharmaceutical companies and medical doctors who are involved in PBSC processing at academic institutions. The complicated regulatory network for the manufacturing of cell products will help to standardize these procedures and ensure consistent quality and safety in the long term. This will be in the interest of patients and reduce risks of application of individual cell preparations.

Amelioration of lung reperfusion injury by L- and E- selectin blockade

OBJECTIVE

Reperfusion injury is the main reason for early graft failure after lung transplantation. Inhibition of the adherence of polymorphonuclear leukocytes to activated endothelium by blocking L- and E-selectins (antibody EL-246) could potentially inhibit reperfusion injury.

METHODS

Reperfusion injury was induced in a left lung autotransplant model in sheep. After hilar stripping the left lung was flushed with Euro-Collins solution and preserved for 2 h in situ at 15 degrees C. After reperfusion right main bronchus and pulmonary artery were occluded leaving the animal dependent on the reperfused lung (control, n = 6). Pulmonary function was assessed by alveolo-arterial oxygen difference (AaDO2) and pulmonary vascular resistance (PVR), the chemiluminescence of isolated neutrophils, as well as the release of beta-N-acetyl-glucosaminidase (beta-NAG) served as indicator of neutrophilic activation. Extravascular lung water was an indicator for pulmonary edema formation. EL-246 group animals (n = 6) were treated additionally with 1 mg/kg BW of EL-246 given prior and during reperfusion.

RESULTS

After 3 h of reperfusion five control animals developed alveolar edema compared to one animal in the EL-246 group (P = 0.08). AaDO2 (mm Hg) was significantly higher in the control compared to the EL-246 group (510 +/- 148 vs. 214 +/- 86). PVR (dyn x s x cm(-5)) was significantly increased in the control compared to the EL-246 group (656 +/- 240 vs. 317 +/- 87). Neutrophilic activation was significantly lower in the EL-246 group. Extravascular lung water was significantly lower compared to control (6.88 +/- 1.0 vs. 13.4 +/- 2.8 g/g blood-free lung weight).

CONCLUSIONS

Treatment with EL-246 results in improved pulmonary function and less in vivo PMN activation in this experimental model. Further studies are necessary to evaluate the possible role of selectin blockade in amelioration of reperfusion injury in human lung transplantation.

Quantitative lymphocyte subset reconstitution after allogeneic hematopoietic transplantation from matched related donors with CD34+ selected PBPC grafts unselected PBPC grafts or BM grafts

CD34+ cell selection of PBPC after harvest from G-CSF-treated allogeneic donors results in a more than 200-fold depletion of T lymphocytes in the graft and has been used to reduce the incidence of acute GVHD post transplant. Since transplantation with T cell-depleted BM grafts is associated with a delay in immune reconstitution and an increase of opportunistic infections, we evaluated the immunological reconstitution of patients with hematologic malignancies after therapy followed by CD34+-selected PBPC34 transplantation from matched related donors. Lymphocyte subset reconstitution over the first 12 months post transplant and the incidence of infections were evaluated in 12 patients receiving PBPC34 grafts and compared to that of patients after transplantation with PBPC without CD34+ enrichment (n = 20) or unmanipulated bone marrow grafts (BM; n = 15). PBPC34 grafts contained 264-fold fewer T lymphocytes (median 0.53 x 10(6) kg/body weight) than PBPC grafts and 36-fold fewer than BM grafts (140 x 10(6)/kg and 19 x 10(6)/kg, respectively). Despite a two log depletion of T cells in the PBPC34 grafts, T lymphocyte reconstitution appeared comparable among the three transplant groups over the first 12 months. A positive patient CMV serostatus pretransplant was correlated with a faster T cell reconstitution in all transplant groups. GVHD prophylaxis with methylprednisolone delayed B lymphocyte reconstitution. The incidence of infections post transplant did not appear to be increased in the PBPC34 group compared with the PBPC and BMT groups. It remains to be shown in larger prospective trials, whether these promising preliminary data of lymphocyte reconstitution and the clinical course after transplantation with PBPC34 can be confirmed.

Multiple organ failure (MOF) after severe trauma--a sheep model

OBJECTIVE

To perform a reproducible long-term (10 days) large animal model of multiple systems organ failure without necessity of a continuous stimulus.

DESIGN

Adult female merino sheep submitted to a 5-day stimulation period followed by a 5-day observation period. Day 1: Hemorrhagic shock was combined with a traumatic surgical insult (reamed intramedullary femoral nailing), followed by serial administrations every 12 h for 5 days of a combination of endotoxin and zymosan activated plasma. Organ function was followed for 5 further days.

RESULTS

Cardiac index increased significantly during the study (day 1: 491 +/- 8 mm Hg; day 10: 427 +/- 20, p < 0.05). Liver function was impaired and bilirubin levels increased significantly (day 1: 2.9 +/- 0.3 micromol/l; day 10: 7.2 +/- 0.9; p < 0.05). Creatinine clearance decreased initially (day 1: 54 +/- 7 ml/min), increased to a peak on day 2 (104 +/- 27), and then deteriorated again (day 10: 53 +/- 18).

CONCLUSION

This new large animal model of trauma-induced MOF is reproducible and may be suitable for the study of new therapeutic approaches to therapy.

Minimal residual disease: detection, clinical relevance, and treatment strategies

Improvement of established treatment strategies for cancer has resulted in increased survival times for patients with malignancies. However, success of surgery, chemotherapy, and radiotherapy is limited, as even combined and repeated therapy regimens and high-dose chemotherapy can only reduce tumor burden by several logarithmic steps and are not able to completely eradicate all neoplastic cells. If clinically complete remission is achieved--that is, if no sign of the tumor is detectable by standard diagnostic procedures, remaining minimal residual disease (MRD) can eventually give rise to clinically manifest relapse. More sensitive methods are, therefore, necessary to detect single tumor cells for exact staging, to assess the metastatic potential of an individual tumor, to evaluate the sensitivity to prior therapy, and to detect MRD-positive patients with remaining malignant cells who are at higher risk for relapse. Novel treatment approaches must be created to eradicate minimal residual disease after conventional therapy.

Investigation of neutrophil--endothelial cell interaction in multiple trauma by chemiluminescence

The trauma-induced activation of neutrophils and their functional alterations, i.e., increase in adherence and release of oxygen derived metabolites, is considered to play a central role in the initiation and amplification of capillary endothelial cell damage and following organ failure. In the present study neutrophil-endothelial cell interaction was studied using an in vitro model of human umbilical cord vein endothelial cells and human neutrophils. Production of oxygen-derived metabolites was determined by comparing mean peak chemiluminescence of neutrophils from multiply traumatized patients (n = 40) and mean peak chemiluminescence of neutrophils from blood donors (n = 160). Adherence and endothelial injury by neutrophils of multiply traumatized patients were compared with data of healthy blood donors. Chemiluminescence response of 70,000 neutrophils isolated from healthy control individuals was 699 +/- 98 x 10(3) cpm and could be increased significantly by endothelial cells to 1410 +/- 135 x 10(3) cpm (p < 0.05). Chemiluminescence response to neutrophils of polytraumatized patients was 1174 +/- 94 x 10(3) cpm and could not be significantly increased by endothelial cells (1419 +/- 120 x 10(3) cpm). Adherence of neutrophils of blood donors to endothelial cells was 12.31 +/- 0.77%. Adherence of neutrophils of polytraumatized patients was significantly increased to values of 24.83 +/- 2.03%. Injury of endothelial cells was not detectable with neutrophils from blood donors (1.11 +/- 1.09% 111in-release). Significantly increased 111in-release was apparent upon incubation with neutrophils of polytraumatized patients (5.76 +/- 1.28%). The data shows evidence of in vivo preactivation of neutrophils of polytraumatized patients, and supports the hypothesis that endothelial cells play an active role in neutrophil-endothelial cell interactions by modulating production of oxygen-derived metabolites.

Attenuation of multiple organ dysfunction in a chronic sheep model by the 21-aminosteroid U74389G

Animal studies have shown that 21-aminosteroids have beneficial effects on cell and organ functions in several acute models of traumatic, hemorrhagic, and septic shock. However, it is not known if the 21-aminosteroid U74389G has any beneficial effect on organ functions in a recently developed chronic sheep model of multiple organ dysfunction after trauma. Furthermore, it is not known whether this drug has any effect on in vivo leukocyte function in this animal model. To study this, anesthetized animals were subjected to hemorrhagic shock (2 hr at a mean arterial blood pressure of 50 mmHg) and femoral reaming at Day 0. The following 5 days, endotoxin (ET; 0.75 micrograms/kg BW) and zymosan-activated plasma (ZAP; 20 ml/animal) were given every 12 hr. During the third phase (Days 6-10), the animals were merely observed. This kind of model resulted in progressive organ dysfunction indicated by increased cardiac output, decreased systemic vascular resistance, an increase of plasma-sorbitoldehydrogenase, impaired bilirubin metabolism, and impaired renal and lung function in nontreated animals. Animals receiving U74389G (3 mg/kg BW) during resuscitation from hemorrhagic shock and each time before ET/ZAP administration showed less severe organ dysfunction. Furthermore, U74389G showed beneficial effects on lung function, although it had no effect on accumulation of leukocytes in the lung or on the chemiluminescence response of isolated leukocytes from bronchoalveolar lavage fluid. These results suggest that U74389G may be a useful therapeutic agent in the prevention of multiple organ dysfunction after hemorrhagic and traumatic shock.

Aprotinin prevents the development of the trauma-induced multiple organ failure in a chronic sheep model

Trauma-induced multiple organ failure in sheep was prevented by aprotinin therapy. Multiple organ failure was induced in 16 female merino sheep by initial haemorrhagic shock and intramedullary femoral nailing (day 0), and 12 hourly injections of 0.75 micrograms/kg Escherichia coli endotoxin +0.7 ml/kg zymosan-activated plasma (days 1-5). In addition, the aprotinin group (n = 6) received simultaneous injections of 5 mg/kg (35 695 KIU/kg) aprotinin, whereas ten animals did not receive aprotinin and served as the control group (n = 10). Organ functions were monitored for a total of 11 days by measuring haemodynamic, cardio-respiratory and biochemical quantities of blood, urine and epithelial lining fluid. During the subsequent eleven day period, aprotinin induced a significant (p < 0.05) reduction of the pathological changes (development of multiple organ failure) seen in the control group. Thus, aprotinin prevented an alteration of cardiac function (cardiac index for control/aprotinin groups at day 1: 6.5/6.2, and at day 10: 10.47/7.0 1/min x m2), an impairment of lung function (mean pulmonary arterial pressure at day 1: 2.26/1.86, and at day 10: 3.83/2.13 kPa; epithelial lining fluid/plasma ratio of albumin concentrations as a direct marker of lung capillary permeability damage at day 0: 0.18/0.16, and at day 10: 0.45/0.15), a deterioration of liver function (plasma sorbitol dehydrogenase at day 0: 7.9/7.6, and at day 10: 29.6/7.4 U/1), but not of renal function (creatinine clearance at day 1: 91.4/66.1, and at day 10: 53.1/59.2 ml/min). Urinary aprotinin excretion increased up to day 3, then decreased rapidly despite further aprotinin administration. As a non-specific marker of cell damage, plasma lactate dehydrogenase indicated an aprotinin-induced organ protection (day 0: 501/409, and at day 10: 719/329 U/1). The neutrophil count and the measured chemiluminescence of neutrophils from the blood and epithelial lining fluid showed that aprotinin reduced the in vivo neutrophil activation, the alveolar neutrophil invasion, the production of inflammatory mediators, and the production of reactive oxygen metabolites during the passage of the capillary-interstitial-alveolar space by neutrophils.

Supplementation of hypercholesterolaemic rabbits with L-arginine reduces the vascular release of superoxide anions and restores NO production

L-arginine, the precursor of endogenous nitric oxide (NO), has been shown to enhance endothelial function and to reduce intimal plaque area in cholesterol (Chol)-fed rabbits. We have studied endogenous NO production in such animals in vitro (endothelium-dependent relaxations) and in vivo (assessed by urinary NO3- excretion) before and during chronic oral administration of L-arginine and inhibitor of NO synthesis, L-NAME. Vascular superoxide anion (O2-) production of aortic rings was measured under basal conditions and following exposure to phorbol-myristate-acetate (PMA). Cholesterol feeding reduced endothelium-dependent relaxations and decreased urinary NO3- excretion. These effects were potentiated by administration of L-NAME. L-arginine partly restored endothelium-dependent relaxations and increased NO3- excretion. PMA-stimulated O2- production was increased in aortic rings from rabbits given cholesterol ( +159 +/- 28%; mean +/- S.E.M.) or cholesterol + L-NAME ( +149 +/- 37%) as compared with controls ( -22 +/- 7%). In rabbits given cholesterol + L-arginine, O2- production was decreased to control levels ( +14 +/- 17%; P < 0.05). We conclude that the systemic synthesis of NO is impaired in cholesterol-fed rabbits, as indicated by the decreased urinary excretion of NO3-. Enhanced O2- production may further contribute to the decreased biological activity of NO in hypercholesterolaemia. L-arginine restores endothelial function in hypercholesterolaemia by enhancing NO production and by protecting NO from early breakdown by O2-.

[Effect of primary fracture management on craniocerebral trauma in polytrauma. An animal experiment study]

Severe head trauma (BI) associated with long bone fractures is present in about 60% of polytraumatized patients admitted to hospital. However, there is no consensus regarding early fracture stabilization in such patients. In an experimental sheep study, the influence of intramedullary nailing of the femur (IMNF) on a cold-induced, vasogenic brain edema (method of Klatzo) in combination with traumatic hemorrhagic shock (THS) was investigated. Three animal groups (n = 6) were explored: group A, only BI; group B, BI and THS; group C, BI, THS and IMNF. The animals remained intubated, on controlled ventilation, sedated and received analgesia during the whole experiment. For a period of 6 h after the cold-induced brain injury the hemodynamic changes were measured and the intracranial pressure (ICP) was recorded in the left and the right hemisphere continuously. The hemorrhagic shock (MAP = 60 mm Hg) was maintained over 1.5 h. At the end of the reperfusion period (2 h) the nailing of the femur was performed. The animals were killed and the percentage water content of the brain was determined and compared with the brain water content of a control group (n = 6). There were no significant differences in ICP between groups A, B and C before or after IMNF, but in group C the ICP increased significantly after nailing. Brain water content in group C was significantly higher than in the control group and slightly significantly higher than in groups A and B. Brain edema and ICP are increased by IMNF.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemiluminescence response and adherence of neutrophils to cultured endothelial cells--influence of immunoglobulin G

The effect of different concentrations (0.8, 4.35, 8.7, 17.5, 25 and 35 mg/mL) of intravenous immunoglobulin G (Endobulin) on neutrophil-endothelial cell interaction was studied using an in vitro model of human umbilical cord vein endothelial cells and human neutrophils. Because adherence of neutrophils to endothelial cells is an essential component in inflammatory processes leading to endothelial cell injury the influence of immunoglobulin G on adherence has been investigated. A second aim of the present study was to determine changes in chemiluminescence response of neutrophils during adherence to endothelial cells. Production of oxygen-derived metabolites, measured by chemiluminescence response of neutrophils, decreased significantly in the presence of 8.7 mg immunoglobulin/mL test during coincubation of neutrophils and endothelial cells (p < 0.025). The adherence of neutrophils to endothelial cells was significantly decreased at a concentration of 8.7 mg immunoglobulin/mL test (p < 0.025). The present results indicate that this preparation of immunoglobulin G might exert a protective effect on neutrophil-endothelial cell interaction by decreasing adherence of neutrophils to endothelial cells and by scavenging reactive oxygen metabolites. metabolites. Therefore, the current investigation points to a probable protective effect of immunoglobulin G in oxidative diseases, such as the adult respiratory distress syndrome.

Intramedullary femoral nailing in sheep: does severe injury predispose to pulmonary dysfunction?

OBJECTIVE

To find out if intramedullary nailing affects lung function and microvascular permeability whether or not the lung is already injured; if so whether a different method of fixation would diminish the effect; and are the pathogenetic changes related to mechanisms known to precipitate adult respiratory distress syndrome?

DESIGN

Experimental study.

SETTING

University hospital, Germany.

MATERIAL

29 Adult female merino sheep.

INTERVENTIONS

Chronic lung lymph fistulas were created. Two of the three groups (1 and 3) underwent right sided lung contusion and haemorrhage to a mean blood pressure of 50 mm Hg for 2 hours. On day 3 groups 1 and 2 underwent intramedullary nailing, and group 3 had external fixators applied.

MAIN OUTCOME MEASURES

Pulmonary arterial pressure, concentrations of triglycerides, chemiluminescence of isolated polymorphonuclear leucocytes (PMN), lymph flow, microvascular pressure, filtration coefficient, and permeability.

RESULTS

Intramedullary nailing caused a transient significant increase in pulmonary arterial pressure and triglycerides in groups 1 and 2. Chemiluminescence of isolated PMN decreased in group 1 and increased in group 2. Lymph flow increased 2.5 times in group 1 while microvascular pressure decreased; in group 2 the increase was less but microvascular pressure increased. Filtration coefficient in group 1 was five times that of group 2 and there was a twofold increase in permeability. There were no changes in group 3.

CONCLUSION

Intramedullary nailing causes additional damage to lungs after lung damage and haemorrhagic shock in sheep. This can be avoided if (in the presence of additional injuries) alternative methods are used.

[A standardized large animal model of multiple organ failure after severe trauma]

In the past various attempts have been made to develop a standardized animal model of multiple organ failure (MOF). Until now there has been no large animal model, that imitates the clinical situation of multiple trauma patients up to MOF. In a manner similar to the pathophysiological sequence in multiple trauma patients, the combination of damaging mechanisms in the early phase (hemorrhagic shock, operating trauma, application of endotoxin (ET; 0.75 microgram/kg body weight) and zymosan-activated plasma (ZAP; 20 ml) every 12 h on days 1-5) leads to sequential irreversible damage to several organs in the late phase (> day 6) in sheep (n = 10). In this animal model representative organ parameters showed a similar course to that in MOF after multiple trauma in humans. The cardiac index increased significantly in the late phase (day 1: 6.47 +/- 0.41 ml/min x m2; day 10: 10.36 +/- 0.79 ml/min x m2), arterial oxygen pressure declined significantly (day 1: 103.1 +/- 1.6 mmHg; day 10: 89.8 +/- 4.2 mmHg). Liver function was impaired, bilirubin levels showed a significant increase (day 1: 2.94 +/- 0.34 mumol/l; day 10: 7.19 +/- 0.91 mumol/l). Creatinine clearance was low on day 1 (54.3 +/- 7.4 ml/min), increased up to day 5 and deteriorated again significantly in the late phase over the entire period (day 2: 104.3 +/- 26.8 ml/min; day 10: 53.1 +/- 17.6 ml/min).

Vascular release of superoxide radicals is enhanced in hypercholesterolemic rabbits

Production/release of superoxide anions from aortic rings was measured by a modified lucigenin-enhanced chemiluminescence (CL) technique. The aortic rings were obtained from control and cholesterol-fed (1% for 12 weeks) rabbits. The CL signal was significantly increased in aortic wall of cholesterol-fed rabbits. Pretreatment with oxypurinol, an inhibitor of xanthine oxidase, had a slight but insignificant effect on the CL response produced by aortic rings from control animals but significantly reduced CL response to aortic rings from cholesterol-fed rabbits. Pretreatment with diethyldithiocarbamate (DETC), an inhibitor of intrinsic superoxide dismutase (SOD), increased the CL signal for both animal groups, but this increase was greatly aggravated in aortic rings from hypercholesterolemic rabbits. Addition of phorbol 12-myristate 13 acetate (PMA) to stimulate the respiratory burst of wall-adherent and/or resident leukocytes had only slight effect on the CL response to aortic rings from control animals but extensively stimulated photon emission of aortic rings from cholesterol-fed rabbits. These findings are in agreement with the concept that the arterial wall in hypercholesterolemia and/or atherosclerosis is under increased "oxidative stress."

Early biochemical indicators of the obliterative bronchiolitis syndrome in lung transplantation

The diagnosis of the obliterative bronchiolitis syndrome in lung transplantation is presently best established by evaluation of postoperative lung function tests. Unfortunately the decline in lung function occurs only when obliteration has progressed significantly and is therefore not an early predictive indicator. To distinguish patients at increased risk for the development of obliterative bronchiolitis, we regularly assessed the chemiluminescence response of polymorphonuclear leukocytes, opsonic capacity, and plasma elastase/beta-N-acetylglucosaminidase in 52 outpatients (25 women and 27 men; mean age 45 +/- 12 years) who underwent transplantation between January 1991 and January 1992. Recent onset bronchiolitis within the described observation period occurred in 16 patients (group obliterative bronchiolitis). A matched cohort of 16 patients was formed according to type of procedure, age and follow-up (control) from the remaining 36 patients. Data obtained from a period 6 months before clinical onset of the syndrome showed a significant drop of the opsonic capacity (group obliterative bronchiolitis = 87% +/- 7%; control = 100% +/- 9%; p < 0.023) and rise of the N-acetyl-D-glucosaminidase (group obliterative bronchiolitis = 7.5 +/- 2 U/L; control = 5.8 +/- 1.8 U/L; p < 0.04). No correlation was found between the number of infectious events or rejection episodes and the incidence of obliterative bronchiolitis. According to these results, it can be concluded that a decrease in the plasma opsonic capacity and a rise in beta-N-acetylglucosaminidase may be early markers before clinical onset of obliterative bronchiolitis. The nonspecific immune system may therefore play an important role in the development of obliterative bronchiolitis.

Neuropeptide levels early after trauma: immunomodulatory effects?

The levels of endogenous opioids, beta-endorphin and methionine-enkephalin, were analyzed in 21 severely traumatized patients (ISS 32, mortality 42.8%) from a first blood sample drawn at the scene of the injury before resuscitation within 32 +/- 16 minutes after the injury and for 8 days after trauma. Additionally, the respiratory burst function of polymorphonuclear neutrophils (PMNs) was assessed and the results were compared with those obtained from 5 healthy control patients undergoing elective surgery with the same analgesic regimen as the multiple trauma patients. Compared with elective surgery anesthesia (controls 3.3, surgery 3.2 fmol/L), the beta-endorphin levels on-scene were markedly elevated (survivors 10.1 fmol/L, non-survivors 15.0 fmol/L) (p < 0.05). Methionine-enkephalin levels after trauma were not different from those of the controls. The stimulation of PMNs with different concentrations of the opioids at the first day after trauma gave results comparable with those of the controls. On the third day after trauma the reactivity of PMNs to low opioid concentrations was markedly suppressed to 79.6% of the baseline value (p < 0.05). Endogenous opioids seem to be able to modulate the nonspecific immune-response after trauma.

Does the reamer type influence the degree of lung dysfunction after femoral nailing following severe trauma? An animal study

In multiple trauma patients with lung contusion, pulmonary complications have been reported that were attributed to intramedullary stabilization of the femur. The reaming procedure of the medullary canal is thought to play a major role. We investigated whether different types of reamers might exert different amounts of fat mobilization into the vascular system and different degrees of pulmonary dysfunction. Adult female Merino sheep were submitted to hemorrhagic shock (2 h, 50 mm Hg) and a unilateral lung contusion; in addition, a lung lymph fistula was created. Pulmonary capillary permeability, central venous triglyceride levels, 11-dehydro-thromboxane B2 (dh-TXB2) levels, and pulmonary artery pressure were determined. After recovery, animals were randomly assigned to intramedullary femoral nailing using several types of reamers: group A, AO reamer (n = 8); group B, Biomet reamer (n = 7); group H, Howmedica reamer (n = 6); group C, controls, no reaming (n = 4). Intramedullary reaming caused a significant (p < 0.05) increase in pulmonary artery pressure in groups A and B; dh-TXB2 levels increased in all groups. Statistically significant (p < 0.05) pulmonary capillary permeability damage was measured in group A only. Intramedullary femoral nailing can cause transient pulmonary hemodynamic and mediator effects as well as increased pulmonary capillary permeability. In the present study, this effect was evident in group A reamer systems only, which may be due to reamer construction.

Increased gut permeability after multiple trauma

Gut permeability was studied in multiply injured patients with respect to the development of multiple organ failure (MOF). Two groups were defined according to MOF score (threshold 10 points) as to whether MOF developed (group 1; n = 11, four deaths) or did not (group 2; n = 21, no death). Gut permeability was determined from the ratio of urinary excretion of enterally administered lactulose and mannitol. Serum elastase concentrations were also determined. Mean(s.e.m.) gut permeability was abnormal during the entire study (day 1: group 1--5.1(2.1) versus group 2--10.6(4.1) (P not significant; P < 0.001 versus normal volunteers, 0.56(0.24)). An increase on days 3 and 5 correlated with serum elastase levels only in patients in group 1 (rs = 0.71, P < 0.01). Severe injury leads to increased intestinal permeability, which is related to a systemic inflammatory response.

Ascorbic acid reduces the endotoxin-induced lung injury in awake sheep

Our aim was to investigate whether ascorbic acid can reduce reactive oxygen metabolite-mediated acute lung injury. The effects of intravenous administration of Escherichia coli endotoxin were studied, with and without ascorbic acid infusion, on haemodynamics, lung lymph flow, cardio-respiratory and neutrophil function in chronically instrumented sheep. Paired experiments were performed on eight sheep in which they received either endotoxin alone (0.5 micrograms kg-1 b.w.) (ET group) or in combination with an ascorbic acid infusion (1 g kg-1 b.w. bolus injection followed by 0.2 g kg-1 h-1 continuous infusion) ET + ASC group) in random order. Four of the animals also received ascorbic acid alone (ASC group). As a result, for the ET + ASC group a general and mostly significant improvement (P < 0.05) in the early hypertensive phase (0-60 min, P values) and in the late permeability phase (2-4 h, *P values) of cardiorespiratory function (mean artery pressure: P/*P = 0.283/0.049; mean pulmonary artery pressure: P/*P = 0.0001/0.0001; mean pulmonary artery wedge pressure: P/*P = 0.012/0.001; right ventricular stroke work index: P/*P = 0.02/0.0001; cardiac index: P/*P = 0.797/0.755; arterial oxygen saturation: P/*P = 0.0059/0.01; arterial-venous difference of oxygen tension: P/*P = 0.011/0.0005), oxygen consumption: P/*P = 0.013/0.035, lung lymph flow: P/*P = 0.562/0.012, lymph/plasma protein ratio: P/*P = 0.304/0.008 and protein clearance: P/*P = 0.56/0.05 was observed in comparison with the ET group.(ABSTRACT TRUNCATED AT 250 WORDS)

The basal and stimulated release of the endothelium-derived relaxing factor from isolated pig coronary arteries does not interfere with the vascular release of superoxide

Oxygen-derived free radicals, in particular superoxide anions, are known to inactivate the endogenous vasodilator endothelium-derived relaxing factor (EDRF) which is probably identical with the gaseous radical nitric oxide. It is possible that EDRF is not the target of superoxide anions but may also be an endogenous scavenger of this radical. Superoxide anions generated by the vessel wall were measured by a modified lucigenin-enhanced chemiluminescence technique in isolated pig coronary artery rings with intact endothelium. The addition of bovine superoxide dismutase, a scavenger of superoxide anions, decreased the chemiluminescence signal by 40 +/- 26% (mean +/- SD; P < 0.05; n = 21) indicating reduced generation/release of superoxide anions. In contrast, pretreatment of coronary artery rings with diethyldithiocarbamate, an inhibitor of the intrinsic copper-zinc superoxide dismutase, increased the chemiluminescence response by 136 +/- 128% (P < 0.05; n = 21). This increase in the chemiluminescence response induced by diethyldithiocarbamate-pretreatment was almost abolished in the presence of added bovine superoxide dismutase. Specific inhibition of the EDRF release with nitro-L-arginine (100 microM) did not affect the chemiluminescence response. On the other hand, stimulation of the EDRF release by substance P (10 nM) or addition of the endothelium-mediated relaxant bradykinin (0.1 microM) did not affect the chemiluminescence response. Stimulation of the EDRF release with serotonin (0.1 microM) significantly reduced the photon emission by 15 +/- 16% (n = 27).(ABSTRACT TRUNCATED AT 250 WORDS)

Influences of different methods of intramedullary femoral nailing on lung function in patients with multiple trauma

We investigated the effects of primary (< or = 24 h) intramedullary femoral nailing on lung function and pulmonary hemodynamics in patients with multiple trauma. Two groups were separated: the group with primary femoral nailing with reaming (group RFN) was submitted to femoral nailing after reaming of the medullary canal; in the group with unreamed femoral nailing (group UFN) a small-diameter solid nail was inserted without reaming. Lung function was assessed by oxygenation ratio (PaO2/FIO2), and pulmonary hemodynamics by intraoperative pulmonary artery catheter measurements. Central venous blood concentrations of elastase and the platelet count were determined during and 3 days after surgery. Lung function was stable in UFN patients (n = 14), but deteriorated in RFN patients (n = 17) from 353 +/- 24 (PaO2/FIO2 preoperatively) to 260 +/- 28 (PaO2/FIO2 postoperatively) (p < 0.05) and improved only after 48 hours. Pulmonary artery pressure (PAP) did not change during surgery in UFN patients; in RFN patients PAP increased from 27.2 +/- 3.1 mm Hg (preoperatively) to 36.3 +/- 4.1 mm Hg (p < 0.05) upon reaming and normalized 1 hour after insertion of the nail. Femoral nailing after reaming represents a potential risk with respect to lung function disturbances. This might trigger the development of adult respiratory distress syndrome (ARDS), especially in patients at extra risk of this complication (additional lung contusion, "borderline patient"). In these cases unreamed femoral nailing might offer an alternative by allowing primary intramedullary stabilization without the risk of adverse effects to the lung.

Effect of prostaglandin E1 on chemiluminescence response and adherence of human polymorphonuclear leukocytes to human cultured endothelial cells of prostaglandin E1 treated polytraumatized patients

We investigated the effect of prostaglandin E1 on human polymorphonuclear leukocytes, in vivo. Polymorphonuclear leukocytes of a prostaglandin E1 and placebo study group were harvested and their function, as production of oxygen-derived metabolites and adherence to human cultured endothelial cells, was compared. Additionally, data obtained from polymorphonuclear leukocytes of a prostaglandin E1 and placebo group were compared with data obtained from polymorphonuclear leukocytes from 28 blood donors, who served as a control group. Production of oxygen-derived metabolites by polymorphonuclear leukocytes during contact with endothelial cells was measured by chemiluminescence. Chemiluminescence was significantly (p < 0.01) increased in the placebo group in comparison to the control group decreasing to values of control group after 6 d (post-trauma). Chemiluminescence response was not significantly suppressed in patients treated with prostaglandin E1 in comparison to the placebo group. Adherence of polymorphonuclear leukocytes (placebo group) to endothelial cells was significantly increased (p < 0.01) within the first 6d post-trauma. Following day 6, values were in the same range as values for the control group. Adherence was not significantly suppressed in patients treated with prostaglandin E1 in comparison to the placebo group. In conclusion, prostaglandin E1 at a dose of 20 ng/kg bw/min does not influence production of oxygen-derived metabolites and adherence in polytraumatized patients in comparison to a placebo group. Additionally, production of oxygen-derived metabolites by polymorphonuclear leukocytes in response to endothelial cells is shown and it is evident that endothelial cells might influence production of oxygen derived metabolites by polymorphonuclear leukocytes.

In vitro effect of ascorbic acid on neutrophil-endothelial cell interaction

The effect of different concentrations (0.06, 0.6 and 6.0 mmol/L) of ascorbic acid on neutrophil-endothelial interaction was studied using an in vitro model of human umbilical cord vein endothelial cells and human neutrophils. The aim of the study was to determine changes in chemiluminescence response of neutrophils during adherence to endothelial cells. Because adherence of neutrophils to endothelial cells is an essential component in inflammatory processes leading to endothelial cell injury, the influence of ascorbic acid on adherence and endothelial cell injury have been investigated. Production of oxygen-derived metabolites, measured by chemiluminescence response of neutrophils, decreased significantly in the presence of 6 mmol/L ascorbic acid during coincubation of neutrophils and endothelial cells (p < 0.025). The adherence of neutrophils to endothelial cells was significantly decreased at a concentration of 6 mmol/L (p < 0.0005). The inhibition of neutrophil adherence to endothelial cells was correlated with a diminished neutrophil-mediated endothelial cell injury during incubation with 6 mmol/L ascorbic acid (p < 0.0005). The present results indicate that ascorbic acid might exert a protective effect on neutrophil-mediated endothelial cell injury by decreasing adherence of neutrophils to endothelial cells and by scavenging reactive oxygen metabolites. Moreover, the current investigation points to probable protective effect of ascorbic acid on oxidant-mediated cell damage in diseases (e.g., Adult Respiratory Distress Syndrome).

[Effects of different intramedullary stabilizing procedures of the femur on lung function in polytrauma]

We investigated the effects of primary (< 24 h) intramedullary femoral nailing on lung function and pulmonary hemodynamics in multiple trauma patients. The standard procedure following reaming of the medullary canal (AFN) was compared with a new procedure using a small, solid nail without prior reaming (UFN). Pulmonary hemodynamics were determined using a pulmonary artery catheter. Global lung function was assessed by means of the oxygenation ratio (PaO2/FiO2). Concentrations of elastase and the platelet count as a general parameter of the clinical course were determined from central venous blood during and 3 days after surgery. The lung function was stable in UFN patients (n = 6), but decreased significantly in AFN patients (n = 10) from 353 +/- 24 (PaO2/FiO2 preoperative) to 260 +/- 28 (PaO2/FiO2 postoperative) and did not improve until 48 h later. Pulmonary artery pressure (Pap) remained within normal limits in UFN patients, whereas in AFN patients Pap increased from 27.4 +/- 3 mm Hg (preoperative) to 37 +/- 3 mm Hg during reaming and did not normalize until 1 h after insertion of the nail. The platelet count remained unchanged in UFN patients and dropped in AFN patients from 143 +/- 25 x 1000 cells/ml blood (preoperative) to 87.5 +/- 15 x 1000 cells/ml blood 2 days after surgery. Our measurements did not show an increase in central venous triglycerides in the AFN group, probably because bone marrow does not become immediately soluble. There was no significant difference between the increase of elactase levels in the two groups. The femoral nailing procedure with reaming in multiple trauma patients involves a potential risk to the lung.(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of human neutrophil elastase in bronchoalveolar lavage fluid: homogeneous immunoactivation versus heterogeneous enzyme immunoassay

Elastase mass concentrations of bronchoalveolar lavage fluid were determined by a homogeneous immunoactivation and a heterogeneous enzyme immunoassay. There was an excellent correlation between both assay systems (y = 1.0376 . x + 1.311; r = 0.9901; n = 43) indicating the suitability of the immunoactivation method for the determination of elastase concentrations in bronchoalveolar lavage fluid as a matrix. Furthermore, dilution of bronchoalveolar lavage fluid samples did not influence the elastase recovery of either assay system.

Pulmonary damage after intramedullary femoral nailing in traumatized sheep--is there an effect from different nailing methods?

Stabilization of femoral shaft fractures is a controversial issue in the management of patients with multiple trauma. Intramedullary nailing usually is preferred primarily; in recent years, however, pulmonary complications (e.g., ARDS) have been reported that were attributed to the reaming procedure. To study the effects of different nailing methods in a model of severe trauma, hemorrhagic shock and lung contusion were created at day 1 in sheep prepared by the method described by Staub. After recuperation (day 3) the animals in the study group (group 1) underwent intramedullary nailing of a closed femur without prior reaming; group 2 was treated with reaming and nailing according to AO standards. The reaming procedure led to an acute increase of pulmonary arterial pressure only in group 2 (19.8 +/- 2.1 to 31.0 +/- 4.6 mm Hg). Pulmonary triglyceride levels increased at parallel time points from 18.27 +/- 2.3 to 33.04 +/- 7.37 mg/dL only in group 2. Stimulatory capacity of polymorphonuclear leukocytes (PMNL) increased in the study group and decreased in controls (group 1: 2.652 +/- 0.23 x 10(6) cpm to 3.387 +/- 1.34 x 10(6) cpm; group 2: 2.699 +/- 0.34 x 10(6) cpm to 2.460 +/- 0.187 x 10(6) cpm). Intramedullary nailing caused an increase of lung capillary permeability in both groups; in the study group less damage was seen (group 1: 0.390 +/- 0.0006 to 0.354 +/- 0.011; group 2: 0.391 +/- 0.0004 to 0.336 +/- 0.015; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Phagocytic cell function in recurrent endotoxemia in sheep

Sepsis syndrome in severely traumatized patients is supposedly due to a blockade of the phagocytic cell system--for example, the reticulo endothelial system (RES) and polymorph nuclear leukocytes (PMNL), which cause insufficient elimination of bacterial substances (e.g., endotoxin). In contrast we found in a previous study using a model of acute endotoxemia that RES clearance is enhanced, while PMNL function gave evidence for decompensation. In order to clarify whether or not our results were just a matter of single dose endotoxemia, we have investigated RES and PMNL function in a sheep model with recurrent endotoxemia. A sheep receiving endotoxin at a dose of 1 microgram/kg body weight every 12 hours was monitored over a 5-day period. RES clearance was calculated by the half-life of Tc99 phytate each day. The PMNL function was determined by measuring chemiluminescence (CL) of isolated PMNL and total blood. The half-life of Tc99 phytate decreased from 56 min to 44 min with endotoxin (P less than or equal to 0.01) the second day and further to 42 min (P less than or equal to 0.002) on the third day. Values then returned to baseline until the end of study. Zymosan induced and luminol enhanced CL response indicated an acute cellular exhaustion after the first endotoxin dose. Under subsequent endotoxin administration, a daily attenuation of the acute response was noted in combination with baseline opsonin capacity. Our results give evidence that also in recurrent endotoxemia RES function is characterized by a sufficient clearance, whereas the PMNL function remains decreased and therefore possibly is responsible for the well-known clinical post-traumatic septic complications.

Effect of ascorbic acid on neutrophil functions and hypoxanthine/xanthine oxidase-generated, oxygen-derived radicals

The chemiluminescence of isolated neutrophils, stimulated with N-formyl-L-methionyl-L-leucyl-L-phenylalanine, latex, lipopolysaccharide from Escherichia coli, zymosan A, or 4 beta-phorbol 12 beta-myristate 13 alpha-acetate was inhibited up to 99% by the dose-dependent oxygen radical scavenging activity of 6 mmol/l ascorbic acid. The chemiluminescence of neutrophils in blood, stimulated with 4 beta-phorbol 12 beta-myristate 13 alpha-acetate, or with zymosan A was inhibited 35% or 48%, respectively, by 6 mmol/l ascorbic acid. Ascorbic acid, up to 6 mmol/l, did not inhibit the release of beta-N-acetylglucosaminidase and elastase from isolated neutrophils activated by the above stimulatory agents. During neutrophil/nylon fibre interaction ascorbic acid reduced the oxygen radical production dose-dependently (77% inhibition of the chemiluminescence response at 6 mmol/l ascorbic acid), whereas the adherence was unaffected. Hypoxanthine/xanthine oxidase-generated oxygen radicals were scavenged by ascorbic acid in a dose-dependent manner (99% inhibition of the chemiluminescence response at 100 mumol/l ascorbic acid). From these results, ascorbic acid can highly be recommended for animal experiments and clinical studies in patients with trauma, shock and sepsis and for studies to prevent or reduce reperfusion injuries.

Effect of recurrent endotoxemia on hemodynamics, lung function and neutrophil activation in sheep

The aim of the study was to find out in which way lung permeability and polymorphonuclear leukocyte (PMNL) functions are modulated under recurrent endotoxin challenge, as it might occur in clinical septic patients. In a sheep model with chronic lung lymph fistula, performing bronchoalveolar lavage (BAL), we investigated the relationship between PMNL function and endothelial as well as epithelial damage in the lung in a sepsis syndrome, using a protocol of recurrent endotoxemia induced by 1 microgram/kg body weight Escherichia coli endotoxin treatment every 12 h over a 5-day period. Pulmonary response showed constantly increased pulmonary arterial pressure at mean values of 24-30 mm Hg. Also, lymph flow did not return to baseline, but remained on a level of 6-9 ml/30 min, after an increase to 12-15 ml/30 min following each endotoxin injection. In contrast, a lower increase in protein clearance was noted upon subsequent endotoxin administration. After initial values of 7-8 ml/30 min following the first endotoxin injection, almost baseline values were measured on the 5th day (3-4 ml/30 min). In systemic hemodynamics, we noted a decrease in cardiac output to 3.0 l/min after the first endotoxin injection, followed by a significant increase to 7 l/min under subsequent endotoxin administration. In PMNL function, we observed an attenuation of the acute response of the decrease in PMNL count, in vitro chemiluminescence response and plasma beta-N-acetylglucosaminidase level. The plasma urea concentration revealed a transient reduction in kidney function. In the epithelial lining fluid (ELF) of the alveoli, total cell count did not change significantly, but the fraction of PMNL increased from 2 to 20% during the 5 days. The ELF/plasma ratios of albumin and total protein did not change significantly. In conclusion, recurrent endotoxemia in a sheep model can produce a hyperdynamic state like in a sepsis syndrome which is further characterized by an initial leakage of the endothelial barrier, only minor affection of the epithelial barrier and by an exhaustion of PMNL function.

[Does lung contusion and general injury severity have an effect on the lung following intramedullary femoral nailing? An animal model]

We evaluated changes in lung function after closed intramedullary femoral nailing (IMN) in sheep. The effects of isolated IMN were compared with those of nailing after lung contusion and hemorrhagic shock. In adult female merino sheep a chronic lung lymph fistula was prepared according to the method described by Staub. At day 1, group 1 received right-sided lung contusion and hemorrhagic shock to a mean blood pressure of 50 mmHg for 2 h. Group 2 was the control group. At day 3 both groups were submitted to IMN, followed by a 2-h observation period. IMN caused a transient significant increase in pulmonary artery pressure and central venous triglycerides in both groups. Chemiluminescence of isolated polymorphonuclear leukocytes (PMNL) decreased in group 1 from 2.699 +/- 0.344 to 2.460 +/- 0.187 x 10(6) cpm/25000 PMNL and increased in group 2 from 2.757 +/- 0.127 to 3.824 +/- 0.439 x 10(6) cpm/25000 PMNL. Lymph flow in group 1 increased 1.5-fold while microvascular pressure decreased. In group 2 lymph flow increased less, while MVP increased. The filtration coefficient in group 1 was 5 times (7.533 +/- 0.044) that in the control group (1.45 +/- 0.133). Calculations of permeability indicated a 2-fold increase (0.044 group 1 vs 0.026 group 2). In the presence of previous lung contusion and hemorrhagic shock there is definite lung damage from IMN. This is probably mediated by stimulation of PMNL.

Relationship between proteolytic enzymes and atherosclerosis in aortic aneurysms

Aortic elastase and aortic collagenase were assayed in 38 patients who underwent an operation for thoracic or infrarenal aneurysm or infrarenal aortic occlusive disease and in 15 control patients (heart or kidney donors). Elastase was elevated in normal aortas of the infrarenal region (1.10 milliunits per gram, p less than 0.05), and in atherosclerotic descendens aneurysms (1.24 milliunits per gram, p less than 0.05), compared with the ascending aorta, when normal; aneurysmatic specimens revealed similar low elastolytic activities (0.10 milliunits per gram). The highest elastase content was found in infrarenal aneurysms (4.65 milliunits per gram). Collagenase assays yielded no significant differences, although higher activities were extracted from aortas of the infrarenal region. Coexistent atherosclerosis and wall destruction were evaluated by macroscopic and histologic investigation. All infrarenal specimens demonstrated severe atherosclerotic wall degeneration with depletion of elastic fibers. As the atherosclerotic specimens did not differ from normal aortas by protease assay, the higher elastase of infrarenal samples compared with the thoracic aorta suggests a more rapid fiber metabolism in the infrarenal region. The significantly elevated elastolytic activity of infrarenal aneurysms points to the decisive role of elastase in infrarenal aneurysm formation.

Simultaneous measurement of endothelial cell damage, elastase release and chemiluminescence response during interaction between polymorphonuclear leukocytes and endothelial cells

Using cultured human umbilical cord vein endothelial cells and human blood neutrophils, the interaction between neutrophils and endothelial cells, in vitro, was studied. The aim of the study was to examine whether a respiratory burst stimulation by neutrophils would be observed by neutrophil/endothelial cell interaction and whether the respiratory burst stimulation of neutrophils by endothelial cells could be enhanced by lipopolysaccharide stimulation of neutrophils. The second aim was whether such an effect, or secretion of elastase, could cause an endothelial cell damage in vitro. Chemiluminescence as an indicator of oxygen-derived metabolites produced by neutrophils, elastase release by neutrophils, and endothelial cell damage, based on 111 In-oxine release from labelled endothelial cells, were measured simultaneously. The present investigation demonstrates that neutrophils can be directly stimulated by endothelial cells. A further amplification of this process following lipopolysaccharide priming up to 10 ng/ml blood could be demonstrated. A slight endothelial cell damage occurs following neutrophil stimulation, although elastase secretion does not increase during interaction between neutrophils and endothelial cells. These results raise the possibility that oxygen-derived metabolites rather than elastase contribute to an endothelial cell damage which might occur in conditions such as endotoxin-induced adult respiratory distress syndrome.

Alveolar cell pattern and chemiluminescence response of blood neutrophils and alveolar macrophages in sheep after endotoxin injection

In order to study the pathomechanisms of the Adult Respiratory Distress Syndrome in an acute animal model, we monitored the alveolar cell pattern and the stimulatory chemiluminescence responses of blood neutrophils and alveolar macrophages in sheep after Escherichia coli endotoxin injection (2 micrograms/kg of body weight). Using appropriate bronchoalveolar lavage techniques, thereby avoiding local inflammation, it was demonstrated that endotoxin injection did not cause any recruitment of neutrophils into the alveoli for a period of up to 24 hours. Following endotoxin injection, blood neutrophils showed a maximal stimulatory response after 5 minutes, and alveolar macrophages after 4 hours. It is concluded that if neutrophils are responsible for initiating the increase in microvascular permeability, then this action must be purely intravascular.

[Humoral and cellular changes of non-specific immune response following severe trauma]

The influence of trauma and hemorrhagic shock on the non-specific immune system has been pointed out in various experimental studies. Other investigations have also been able to find a relationship between these changes and a higher incidence of post-traumatic complications in the form of organ failure. Our aim was to demonstrate the potential changes in the cellular defense system in a clinical study on multiple trauma patients. The polymorphonuclear leukocytes (PMNL) are the main representative of the mobile, non-specific immune system. Our study revealed a significant deterioration of PMNL function after trauma. The metabolic activity and phagocytic function were mainly affected by a decrease in the concentration of so-called "opsonins." The opsonins are important for the identification and engulfment of debris (necrosis, fat emboli and thrombi) and bacterial substances (endotoxin). Next to the opsonin level, a change in the receptor configuration is important for phagocytosis. However, we could not find any substantial evidence of surface receptor alteration. The reticuloendothelial cells (RES), a stationary phagocytic system, also showed a significant reduction in clearance function in these polytraumatized patients. Similar to PMNL, these disturbances were based on the reduction of the opsonine concentration. We were able to demonstrate a significant disturbance in immune function in multiple trauma patients with post-traumatic complications compared to patients with a normal clinical course after injury. Disturbances in the PMNL function (seen after 4 days) were found to appear after the RES disturbances. Systemic interaction between these two phagocytic systems cannot be excluded and further investigation is therefore required.

Lipopolysaccharide-dependent enhancement of adherence-mediated chemiluminescence response of polymorphonuclear leukocytes

Adherence of resting polymorphonuclear leukocytes to nylon fibre increased the chemiluminescence response (CL) from 99,400 to 910,300 cpm/25,000 PMNL. This effect could be amplified by lipopolysaccharide (LPS) priming of granulocytes in a dose-dependent fashion. The results of nylon fibre adherence experiments suggest an in vitro model that might approximate certain conditions of in vivo PMNL-endothelial adherence and respiratory burst activation, and these reactions of polymorphonuclear leukocytes may contribute to the pathomechanisms of the Adult Respiratory Distress Syndrome.

Mechanisms of non-opsonized zymosan-induced and luminol-enhanced chemiluminescence in whole blood and isolated phagocytes

A luminol-dependent non-opsonized zymosan-induced chemiluminescence method for phagocytes in small quantities of whole blood (40 microliters; final dilution: 1:14) is described. It was characterized with reference to cellular and humoral components, and also applied to isolated neutrophils, eosinophils and monocytes. Normal values for whole blood chemiluminescence and for neutrophils, eosinophils and monocytes are presented. From the chemiluminescence characteristic of distinct phagocytes and their frequency distribution pattern in whole blood, it is concluded that whole blood chemiluminescence has its source predominantly in neutrophils. The question as to the origin of chemiluminescence in phagocytes of whole blood and isolated neutrophils is investigated. The results support the importance of the myeloperoxidase-H2O2-halide system, but also go beyond this. The release of arachidonic acid by phospholipase A2 and of diacylglycerol and inositol trisphosphate by phospholipase C, the metabolism of arachidonic acid by the cyclooxygenase and lipoxygenase pathway, the activation of membrane NADPH oxidase by diacylglycerol and the calcium mobilisation by inositol trisphosphate are necessary for the chemiluminescence reaction. Inhibition of either mechanism suppresses the chemiluminescence response. The interaction of non-opsonized zymosan with plasma opsonins, phagocyte Fc- and complement receptors, respectively, for the initiation of chemiluminescence, was investigated. Non-opsonized zymosan initiates a chemiluminescence response in blood phagocytes in the absence of opsonin from the interaction of the zymosan polysaccharide component glucan with the complement receptor type 3. In the presence of plasma this receptor type also mediates the major chemiluminescence response brought about by the zymosan-coated cleavage products of complement fraction three, iC3b and to a minor degree C3b, while immunoglobulin G-coated zymosan interaction with the Fc-receptor is in this case of minor importance.

Phagocytic function of polymorphonuclear leukocytes and the RES in endotoxemia

The reticuloendothelial system (RES) and the polymorphonuclear leukocytes (PMNs) are thought to play a major role in defense against sepsis. Disturbances in the function of these two phagocytic systems during a septic event is associated with the development of lung capillary injury. Endotoxemia is said to lead to similar changes. Our study examined the function of the RES and PMNs after bolus injection of endotoxin (2 micrograms/kg BW) in a standardized sheep model. For up to 24 hr after endotoxin, blood samples were drawn and PMN function was followed by chemiluminescence, chemotaxis, and adherence as well as the phagocytosis and killing of bacteria. RES function was determined by the blood clearance of a labeled Tc99 colloid. We found an increase of RES clearance directly after endotoxin. Chemotaxis, phagocytosis, and killing were reduced. Adherence was increased. Chemiluminescence peak maximum (CLPM), representing the metabolic activity of the PMNs, was initially increased but shortly thereafter showed a significant decline (at 1 hr: 0.52 +/- 0.13 X 10(6) cpm with P less than 0.05 compared to baseline). The chemiluminescence peak time (CLPT), a measure of membrane receptor function, was significantly reduced (10.0 +/- 2.2 min with P less than 0.001 compared to baseline). Endotoxin led to a reduction of intracellular PMN functions (phagocytosis, killing, CLPM) within 1 hr. Membrane localized functions (adherence, CLPT) were increased. The changes in PMN function might be the reason for the development of lung capillary injury, in spite of undisturbed RES clearance.

Evaluation of elastase and alpha 1-proteinase inhibitor-elastase uptake by polymorphonuclear leukocytes and evidence of an elastase-specific receptor

Neither resting nor stimulated isolated human polymorphonuclear leukocytes did bind or ingest preformed complexes of alpha 1-proteinase inhibitor and unlabeled/125I-labeled human leukocyte elastase. In contrast, granulocytes bound unlabeled/125I-labeled elastase and the extent of binding was reduced in the presence of respiratory burst stimulators, such as 4 beta-phorbol 12 beta-myristate 13 alpha-acetate, E. coli endotoxin, and N-formyl-L-methionyl-L-leucyl-L-phenylalanine. In association/dissociation and competition inhibition experiments it was demonstrated that granulocyte-elastase binding was specific and saturable. From Scatchard and non-linear regression analysis there was evidence of a two-class receptor model with independent binding sites. Calculated by the non-linear regression method assuming a two-class receptor model the characteristics of the high affinity/low capacity binding site were K1 = 216 +/- 129 X 10(6) l X mol-1 (means +/- s; n = 3) and R1 = 1.38 +/- 0.95 nmol X l-1 corresponding to 0.083 X 10(6) receptors per cell, whereas the low affinity/high capacity binding site had the characteristics K2 = 0.50 +/- 0.09 X 10(6) l X mol-1 and R2 = 237 +/- 103 nmol X l-1 corresponding to 14.3 +/- 6.2 X 10(6) receptors per cell.

Bronchoalveolar lavage fluid and plasma proteins, chemiluminescence response and protein contents of polymorphonuclear leukocytes from blood and lavage fluid in traumatized patients

The technique of bronchoalveolar lavage was used to obtain serial samples of lavage every two days from non-contused lung areas of seven traumatized patients and four normals; blood was drawn simultaneously. Urea, total protein, albumin, alpha 1-proteinase inhibitor, alpha 2-macroglobulin, lactate dehydrogenase, beta-N-acetyl-glucosaminidase, myeloperoxidase, and elastase enzyme activity, as well as complexed and total elastase concentrations were determined in bronchoalveolar lavage fluids and plasma samples. Lavage fluid cell pattern was counted. Polymorphonuclear leukocytes were isolated from lavage fluids and blood samples. Granulocyte contents of elastase enzyme activity, complexed and total elastase concentrations, and myeloperoxidase and lactate dehydrogenase activity were determined. Polymorphonuclear leukocyte stimulatory functions were measured by luminol-enhanced chemiluminescence. The following results were obtained for the patient group: Patterns of lavage fluid cells were shifted in favour of polymorphonuclear leukocytes and lymphocytes. The protein determinations of bronchoalveolar lavage fluids and plasma samples gave information about the extent of alterations of permeability of the capillary-interstitial-alveolar space (albumin/urea and alpha 1-proteinase inhibitor/urea ratios) as well as about the amounts of cytoplasmic and lysosomal enzymes released by phagocytes (lactate dehydrogenase/urea, beta-N-acetylglucosaminidase/urea, elastase/urea ratios). Polymorphonuclear leukocytes isolated from bronchoalveolar lavage fluids contained a decreased content of myeloperoxidase and elastase enzyme activities and total elastase concentration; the content of complexed elastase was found to be increased more than 100 fold. From chemiluminescence measurements there was evidence for decreased zymosan-induced stimulatory function, while the photon emission rate of polymorphonuclear leukocytes after passage into the alveolar space was increased.

Radioimmunoassay: an overview

The historical development, principle and theory of the radioimmunological test are described, together with the necessary test components, separation techniques and experimental procedure. The emphasis on different areas of diagnosis that rely on radioimmunoassay is compared for two institutions. Methods for the determination and presentation of reliability criteria are described, and the current status of quality control of radioimmunological methods is discussed. Three high grade mechanized systems and five fully mechanized or automated systems for radioimmunological assays are presented. Future trends in the development of radioimmunoassay can be predicted with the aid of general growth criteria.

Insulin binding and degradation studies on erythrocytes at different temperatures

Insulin binding of human erythrocytes has been investigated between 0 and 37 degrees C using porcine 125I-insulin/unlabeled porcine insulin and mono [125I] (Tyr-A14)biosynthetic human insulin/ unlabeled biosynthetic human insulin, respectively. Either system exhibited a regular thermodynamical behavior between 0 and 22 degrees C, giving unitary free-energy changes of about -58/ -59 kJ/mol, unitary entropy changes of about +55/ +70 J/K per mol and a reaction heat of -43.1/ -38.3 kJ/mol. From 22 up to 37 degrees C an irregular thermodynamical behavior could be observed, which can be partially explained by an increased insulin degradation during incubation and an additional time-dependent binding of the degradation products.