Involvement of p38 mitogen-activated protein kinase in the induction of tolerance to hemorrhagic and endotoxic shock.

BACKGROUND: Exposure to sublethal hemorrhage (SLH) makes rats tolerant to subsequent hemorrhagic or septic shock and is associated with altered NF-kappaB activity. The purpose of this study was to explore whether changes in p38 mitogen-activated protein (MAP) kinase activity also occur in the induction of tolerance by SLH. METHODS: Rats were made tolerant by SLH or sham operation. Twenty-four hours later rats were exposed to lipopolysaccharide (LPS) or had peritoneal macrophages (Mphi) isolated. CNI-1493, a p38 MAP kinase inhibitor, or saline was given prior to SLH. Lungs were harvested 1 h after SLH or LPS and total protein was extracted. Peritoneal Mphi were stimulated with LPS (10 microg/ml) and total protein was isolated 1 h later. Active, dually phosphorylated p38 MAP kinase was determined by Western blot. Tumor necrosis factor (TNF) was measured in Mphi supernatants by enzyme-linked immunosorbent assay (ELISA) 18 h after LPS. RESULTS: SLH activated p38 MAP kinase in the lung and this was inhibited by CNI-1493. Twenty-four hours later, lung p38 MAP kinase activity increased to the same degree in tolerant and sham rats following LPS, but much more prominently in the CNI-1493 treated rats. There was no p38 activity in peritoneal Mphi at baseline, and similar to lung p38, LPS led to increased p38 activity which was most significant in Mphi from rats that received CNI-1493 prior to SLH. TNF production by tolerant Mphi in response to LPS was significantly (P < 0.05, t test) decreased and p38 inhibition with CNI-1493 at the time of SLH reversed the inhibitory effects of tolerance on TNF production. CONCLUSIONS: TNF production by tolerant Mphi following a second insult (LPS) is attenuated despite preservation of normal p38 MAP kinase activity. However, activation of this intracellular second messenger is a necessary step in the "cellular reprogramming" that occurs during the induction of tolerance by SLH.

Tolerance to shock: an exploration of mechanism.

OBJECTIVE: To determine if cross-tolerance to septic shock could be induced by a previous insult with sublethal hemorrhage (SLH) and to characterize the mechanisms involved in this induced protective response. BACKGROUND DATA: It is possible to condition animals by prior SLH such that they tolerate an otherwise lethal hemorrhage. It is also possible to condition animals with low doses of lipopolysaccharide (LPS) so that they survive a "lethal" septic insult. However, a paucity of information exists on cross-tolerance between hemorrhage and sepsis. METHODS: Rats were made tolerant by conditioning SLH or sham operation. Twenty-four hours later, tolerant and sham rats were exposed to a lethal dose of LPS. To explore the mechanism of tolerance induction, rats were given the macrophage (Mphi) inhibitor CNI-1493 or saline carrier before SLH. Survival and pulmonary vascular injury were determined after LPS. Serum tumor necrosis factor (TNF) levels and splenic Mphi TNF gene expression were measured at several time points. RESULTS: Prior SLH indeed made rats tolerant and imparted a significant survival benefit and reduction in pulmonary vascular injury after LPS. The tolerance induced by SLH was reversed by Mphi inhibition. Tolerant animals had low serum TNF levels immediately after SLH and reduced circulating TNF levels after LPS. SLH, however, did not inhibit the augmentation of TNF gene expression after LPS. CONCLUSIONS: Sublethal hemorrhage bestows protection against a lethal LPS challenge. Inhibition of the Mphi attenuated the benefit of the tolerance induced by SLH. Circulating TNF but not TNF gene after LPS is lessened by SLH. This implicates changes in Mphi intracellular signaling in induction of the tolerant state.

Renal ischemia/reperfusion leads to macrophage-mediated increase in pulmonary vascular permeability.

BACKGROUND: Despite the advent of dialysis, survival with acute renal failure when associated with multiorgan failure is poor. The development of lung injury after shock or visceral ischemia has been shown; however, the effects of isolated renal ischemia/reperfusion injury (IRI) on the lungs are unclear. We hypothesized that isolated renal IRI could alter pulmonary vascular permeability (PVP) and that macrophages could be important mediators in this response. METHODS: Rats (N = 5 per group) underwent renal ischemia for 30 minutes, followed by reperfusion. Lung vascular permeability was evaluated by quantitation of Evans blue dye extravasation from vascular space to lung parenchyma at 1, 24, 48, or 96 hours after reperfusion. Serum was collected for blood urea nitrogen and creatinine at each time point. To examine the role of the macrophage, the macrophage pacifant CNI-1493, which inhibits the release of macrophage-derived inflammatory products, was administered in a blinded fashion during renal IRI. RESULTS: PVP was significantly (P < 0.05) increased at 24 hours and peaked at 48 hours after IRI compared with shams as well as baseline levels. PVP after IRI became similar to shams after 96 hours. This correlated with increases in blood urea nitrogen and creatinine at similar time points. At 48 hours, CNI-1493 significantly abrogated the increase in PVP compared with IRI alone. However, CNI-1493 did not alter the course of the acute renal failure. Pulmonary histology demonstrated interstitial edema, alveolar hemorrhage, and red blood cell sludging after renal IRI, which was partially attenuated by CNI-1493. CONCLUSIONS: Increased PVP develops after isolated renal IRI, and macrophage-derived products are mediators in this response. These findings have implications for understanding the mechanisms underlying respiratory dysfunction associated with acute renal failure.

Induction of tolerance to hemorrhagic or endotoxic shock involves activation of NF-kappaB.

BACKGROUND: Tolerance to hemorrhagic or endotoxic shock can be induced by prior sublethal hemorrhage (SLH). The purpose of this study was to explore whether alterations in signal transduction pathways involving NF-kappaB occur in macrophages (Mphi) following induction of tolerance by SLH. METHODS: Using a model of SLH previously shown in our lab to impart a survival benefit to subsequent hemorrhagic or endotoxic shock, rats (n = 30) were conditioned by SLH. Peritoneal Mphi were harvested 24 h after conditioning and stimulated with lipopolysaccharide (LPS) (10 microg/mL). Nuclear and cytosolic proteins were isolated 1 h later for determination of NF-kappaB activation by gel-shift assay and IkappaB-alpha by Western blot. TNF mRNA gene expression was measured 4 h after LPS stimulation by reverse transcription/polymerase chain reaction (RT/PCR). TNF protein levels were measured in cellular supernatants by enzyme-linked immunosorbent assay (ELISA) 18 h after LPS. RESULTS. LPS stimulation of sham Mphi increased NF-kappaB activation with corresponding loss of its inhibitor IkappaB-alpha. In contrast, IkappaB-alpha was not detectable following conditioning, and conditioned Mphi had NF-kappaB activation at baseline which increased minimally with LPS stimulation. LPS increased TNF gene expression and significantly increased protein production by both sham and conditioned Mphi, but this increase was greater in the sham-conditioned group. CONCLUSIONS: The ability of Mphi from animals made tolerant by SLH to produce TNF in vitro is conserved. Nevertheless, these same Mphi exhibit alterations in TNF gene induction and expression as well as signal transduction, specifically, changes in IkappaB-alpha and NF-kappaB activation. This suggests a role for activation of NF-kappaB in the induction of tolerance.

Sublethal hemorrhage blunts the inflammatory cytokine response to endotoxin in a rat model.

BACKGROUND: Tolerance to lipopolysaccharide (LPS) induced by previous hemorrhage in mice is associated with a blunted interleukin 1 (IL-1) response, suggesting down-regulation of the cytokine cascade as a possible protective mechanism. This study was undertaken to determine whether prehemorrhage induces attenuation of the cytokine response to sepsis beyond IL-1 in a rat model and whether this response occurs at the level of gene transcription. METHODS: Sprague-Dawley rats underwent sublethal hemorrhage, lethal intraperitoneal endotoxin, or sublethal hemorrhage with delayed lethal endotoxin. Animals were killed 12 hours after LPS injection or 24 hours after hemorrhage. IL-1 and tumor necrosis factor (TNF) mRNA levels were determined on total splenic RNA using reverse-transcriptase polymerase chain reaction, and serum cytokine levels were determined using enzyme-linked immunosorbent assay. RESULTS: Animals that received LPS alone mounted an IL-1 and TNF response (RNA and protein) much higher than animals subjected to hemorrhage alone. TNF and IL-1 gene expression and protein levels in prehemorrhaged animals that received LPS, however, were significantly lower than those of animals that received LPS alone. CONCLUSION: Hemorrhage induces early IL-1 and TNF gene expression, which blunts their subsequent expected increase after endotoxic challenge. These findings validate previously documented immune-modulated protective effects of the first insult in a two-hit model.

Respiratory syncytial virus immune globulin for prophylaxis against respiratory syncytial virus disease in infants and children with congenital heart disease. The Cardiac Study Group.

OBJECTIVE: To examine the effectiveness of respiratory syncytial virus immune globulin administered intravenously (RSV-IGIV) in reducing hospitalization for treatment of RSV in children with congenital heart disease (CHD). METHODS: Children younger than 4 years of age were randomly assigned to a treatment group receiving RSV-IGIV, 750 mg/kg, monthly or to a control group not receiving infusions. Surveillance for respiratory tract infections was carried out and management decisions were made by physicians blinded to treatment group. RESULTS: Hospitalization for treatment of an RSV infection occurred in 32 of 214 (15%) of control children and 21 of 202 (10%) of the children receiving RSV-IGIV, a 31% reduction (P = .16). However, in infants younger than 6 months of age at study entry, 20 of 82 (24%) in the control group and 10 of 96 (10%) in the RSV-IGIV group had RSV hospitalizations (58% reduction, P = .01). The incidence of hospitalization for any respiratory tract symptomatology was lower in the RSV-IGIV group (34 of 202, 17%) than in the control group (57 of 214, 27%; P = .02). There was a significantly higher frequency of unanticipated cyanotic episodes and of poor outcomes after surgery among children with cyanotic CHD in the RSV-IGIV group (22 of 78, 28%) than in the control group (4 of 47, 8.5%; P = .009). CONCLUSION: RSV-IGIV should not be used for prophylaxis of RSV disease in children with cyanotic CHD. RSV-IGIV did not reduce RSV hospitalization in all children with CHD, but it was effective in preventing RSV hospitalization in infants younger than 6 months of age. Further studies in these children are indicated.

The physiologic consequences of macrophage pacification during severe acute pancreatitis.

Macrophage overproduction of inflammatory mediators is detrimental in the progression of acute pancreatitis. Although inhibition of inflammatory mediators has been shown to decrease the severity of experimental pancreatitis and improve overall survival, less is known about the mechanism by which blockade produces these benefits. Prior to the induction of lethal acute pancreatitis, rats were randomized to receive a single dose (.01, .1, 1.0, or 10 mg/kg) of a macrophage-pacifying compound (CNI-1493) or vehicle. Escalating doses provided incremental increases in survival from 10% (vehicle) to a maximum of 70% (CNI-1493, 1.0 mg/kg). To evaluate the physiologic mechanism responsible for the improved survival, continuous arterial blood pressure, serial hematocrit, ascites volume, pancreatic edema, bronchoalveolar leukocytes and protein, and pancreatic histology were determined in additional rats receiving CNI-1493 (1.0 mg/kg). Serum tumor necrosis factor-alpha and nitrites were also determined to assess the mechanism of action of CNI-1493. Macrophage pacification decreased pancreatitis severity as determined by enzyme release and pancreatic histology score. Ascites volume and bronchoalveolar protein levels were also decreased, indicating that CNI-1493 prevents the loss of circulating blood volume and maintains hematocrit and mean arterial pressure, thus improving survival. CNI-1493 prevented the increase of serum tumor necrosis factor-alpha but not serum nitrites, implicating macrophage-derived cytokines and not nitric oxide in the pathogenesis of physiologic decompensation and death in this model of pancreatitis.

Respiratory syncytial virus (RSV) immune globulin intravenous therapy for RSV lower respiratory tract infection in infants and young children at high risk for severe RSV infections: Respiratory Syncytial Virus Immune Globulin Study Group.

OBJECTIVES: To evaluate the efficacy of high-titer intravenous respiratory syncytial virus immune globulin (RSVIG) in the treatment of children at high risk for severe RSV infection who were hospitalized with proven RSV. METHODS: Infants and young children younger than 2 years with bronchopulmonary dysplasia, chronic lung disease, congenital heart disease, or prematurity (<32 weeks' gestational age), hospitalized with a history of lower respiratory tract infection (LRI) of less than 4 days, were enrolled in this study. Patients were randomized in a blinded fashion to receive either 1500 mg/kg RSVIG or placebo in equal volumes. They were evaluated daily for safety and respiratory scores and for RSV nasal shedding. RESULTS: One hundred seven high-risk children were randomized--54 in the RSVIG group and 53 in the placebo group. Of these children, 51 in each group were considered evaluable. Children with pulmonary disease, congenital heart disease, or prematurity were equally distributed between the two treatment groups. However, two important differences were found in baseline variables between the two groups: there were more patients in the placebo group who had histories of previous LRI and there was a trend toward more severe disease at study entry in the RSVIG group. This was manifested by a higher entry respiratory score in the RSVIG group than in the placebo group (3.4 +/- 0.2 vs 3.1 +/- .01). A higher proportion of children in the RSVIG group (47%) than in the placebo group (28%) required intensive care at entry and mechanical ventilation at study entry (31% RSVIG-treated vs 18% placebo-treated patients). No significant difference was found between groups in the mean unadjusted duration of hospitalization (RSVIG group, 9.10 +/- 1.18 days; control group, 8.17 +/- 1.08 days). When the mean was adjusted for entry respiratory score, likewise, no difference was observed between each group (8.41 +/- 0.97 vs 8.89 +/- .99 days). The lack of efficacy observed in the study primary endpoint was observed in all diagnostic groups. No differences between the RSVIG and placebo groups were observed in the following secondary endpoints: duration of intensive care unit stay, duration of intensive care unit stay for RSV, mechanical ventilation, or supplemental oxygen. No significant differences in adverse events were reported in the RSVIG group (16 children) when compared with the control group (10 children). CONCLUSION: RSVIG treatment was safe but not efficacious in the treatment of children with bronchopulmonary dysplasia, congenital heart disease, or premature gestation who were hospitalized with RSV LRI.

Virus-specific antibody responses to human cytomegalovirus (HCMV) in human immunodeficiency virus type 1-infected persons with HCMV retinitis.

Human cytomegalovirus (HCMV) causes retinitis and is the leading cause of blindness in patients infected with the human immunodeficiency virus (HIV). While most patients with HIV are HCMV seropositive, not all will develop clinical complications from it. The immune responses that can prevent the development of HCMV retinitis are unknown. The levels of anti-HCMV antibodies, including responses to the two major envelope proteins, gpUL55 (gB) and gpUL75 (gH), which are the targets of neutralizing antibody (NA), were examined in HIV-infected patients with and without retinitis. No specific deficiency in the antibody response of retinitis patients was observed. However, higher levels of NA were associated with a more favorable clinical course. These results indicate that antibodies may modulate progression of disease, and they suggest a possible role for the exogenous administration of NA in patients who develop HCMV retinitis.

Candidate recombinant vaccine for human B19 parvovirus.

Recombinant baculoviruses were used to produce human B19 parvovirus empty capsids composed of only VP2 and VP2 capsids containing 4%, 25%, 35%, or 41% VP1 protein. Immunogenicity of the purified capsids, formulated with or without adjuvant, was evaluated in mice, guinea pigs, and rabbits. Sera were analyzed for total anti-B19 parvovirus antibodies, antibodies specific to the region unique to the VP1 capsid protein, and virus neutralizing antibodies. A relationship was observed between the development of antibodies specific to sequences unique to the VP1 protein and virus neutralization. The polypeptide composition of the empty capsid immunogens appeared to be important for elicitation of potent virus neutralizing activity. VP2 capsid immunogens devoid of VP1 protein, or consisting of only 4% VP1, the composition of naturally occurring virions, were generally poor at eliciting high levels of virus neutralizing activity. Capsids consisting of > or = 25% VP1 protein efficiently and consistently provoked vigorous B19 virus neutralizing responses. Recombinant empty capsids enriched for the VP1 protein should serve as the basis for a human B19 parvovirus vaccine.

Familial aggregation of bladder cancer stratified by smoking status.

To assess bladder cancer incidence in first-degree relatives of affected probands, bladder cancer patients and matched control probands provided general demographic and smoking information on their first-degree relatives. Bladder cancer incidence was established through information from the New York State Tumor Registry. The risk ratio for relatives of case probands versus relatives of control probands was 1.9; for relatives who smoked, the risk ratio was 2.1, while for nonsmoking relatives, the risk ratio was 1.8. Results from a proportional hazards regression analysis agreed with those above. These results indicate a familial component that is independent of smoking.

Familial aggregation of congenital dislocation of the hip in a Norwegian population.

Previous studies of congenital dislocation of the hip have not used adequate control groups in estimating the level of genetic influence on that trait. Furthermore, it could not be demonstrated that alleged maternal effects were not an artifact of reporting bias. To that end, information was obtained on the presence of the anomaly in the families of adult twins and their spouses participating in the Norwegian Twin Registry. The prevalence odds ratio for having that disorder in first degree relatives was 10.0. Stratifying by class of relatives, the prevalence odds ratio was 8.1 for fathers, 35.8 for mothers, 12.7 for siblings, and 3.3 for offspring. The increased prevalence odds ratio for mothers over that of fathers suggests a maternal effect. Since both males and females reported on the anomaly for each parental type, it is unlikely that the difference in prevalence odds ratios is due to general reporting bias.

The effect of perinatal screening in Norway on the magnitude of noninherited risk factors for congenital dislocation of the hip.

Several investigators have noted an increase in the rate of congenital dislocation of the hip shortly after the initiation of neonatal screening procedures. This increase has been attributed to the detection of temporarily unstable hips which require no corrective treatment. To test whether neonatal screening had low specificity, the authors obtained data on 17,145 offspring of 7,896 twins from the Norwegian Twin Panel. Information from maternal reproduction history questionnaires was available on the presence or absence of congenital dislocation of the hip, type of obstetric delivery, and parity. The reported prevalence of the disorder did indeed begin to rise sharply during the late 1950s, at which time neonatal screening started in Norway. Infants were then grouped by year of birth (born before or after 1960), and odds ratios were calculated for breech delivery and early (first or second) parity. For the pre-screening group, the odds ratio of congenital dislocation of the hip was 7.7 among children delivered by breech presentation and 2.6 among those of early parity. These values are similar to those found in other studies. In the post-screening group, the odds ratios for breech delivery and early parity were 1.5 and 1.2, respectively. Breech delivery and early parity have been consistent risk factors for congenital dislocation of the hip. Their diminished influence in the post-screening group, as well as sharply increased rates of the disorder, suggests that in Norway neonatal screening programs may have had low specificity in detecting cases that required treatment.

[Differential diagnosis of arterial hypertension at a city polyclinic with mass population screening]. / Differntsial'naia diagnostika arterial'noi gipertenzii v usloviiakh gorodskoi polikliniki pri massovom obsledovanii naseleniia.

The paper discusses the problems of differential diagnosis between varying types of arterial hypertension detected during mass screening of the population. Randomized examination was made in 45% of male population aged 40-59 years. Arterial hypertension was observed in 26.3% of the examinee; 24.5% showed a rise in the arterial pressure for the first time. The methods of investigation available at the city polyclinic allowed the authors to diagnose hypertension in 85.2% of the patients. The results of isotope renography included into the complex of the study enabled them to determine the indications for the method to be used in mass screening of the population for revealing arterial hypertension.

[Myocardial scintigraphy in the diagnosis of infarct in patients with disorders of intraventricular conduction]. / Stsintigrafiia miokarda v diagnostike infarkta u bol'nykh s narusheniiami vnutrizheludochkovoi provodimosti.

Myocardial scintigraphy with pyrophosphate-99mTc-Sn was used as a diagnostic test in 23 patients with different disorders of rhythm and intracardia conduction who were admitted to the department of emergency cardiology of the All-Union Cardiological Scientific Center, Academy of Medical Sciences of the USSR with suspected acute myocardial infarction. Scintigrams were positive in 11 of 12 patients with acute myocardial infarction who were examined in periods of 6 hours of 10 days. One patient examined on the 13th day of the disease had negative scintigrams. In 6 of 11 patients with myocardial infarction not confirmed, the scintigrams were also negative, in 3 other patients positive scintigrams were due to a postinfarction aneurysm. The authors conclude that myocardial scintigraphy with pyrophosphate-99mTc-Sn is an adequate test in the diagnosis of acute myocardial infarction, especially in the examination of patients with disorders of intracardiac conduction.

[Hormones in ischemic heart disease with the presence of coronary atherosclerosis]. / Gormony pri ishemicheskoi bolezni serdtsa s nalichiem koronarnogo aterosckleroza.

The activity of the pituitary hormones (ACTH, STH, TTH, FSH, LH), the adrenal hormones (cortisol, aldosterone), the kidney hormone (renin), and the thyroid hormones (thyroxine tri-iodthyronine), the thyroxine binding capacity of blood proteins and the activity of the hormones of the pancreas (insulin) and the sex glands (testosterone, estradiol) were studied in 26 males suffering from ischemic heart disease verified by means of selective coronarography and in 20 healthy males with no atherosclerosis of the coronary arteries of the heart. Patients with ischemic heart disease were found to be marked by increased activity in the blood of ACTH, TTH, cortisol, aldosterone, insulin, and estradiol and reduced concentration of STH, thyroxine, and testosterone. These shifts in the activity of the hypothalamo-hypophyseal system and in its subordinate hormonal systems play an important role in the origin of the atherosclerotic process and assosiated ischemic heart disease.

[Content of total metabolic sodium in arterial hypertension of varying origin]. / Soderzhanie obshchego obmennogo natriia u bol'nykh arterial'noi gipertoniei razlichnogo proiskhozhdeniia

The content of total metabolizing sodium was studied in 74 patients with hypertension of different genesis, using the Na24-isotope dilution technique. Among these patients 31 had essential hypertension, 43--symptomatic hypertension (40--renal, and 3--adrenal). In Stage IB and IIA hypertension, a reduction of the level of total metabolizing sodium and its increased urine excretion were found. At late stages of essential hypertension, like in symptomatic renal hypertension, normal levels of total metabolizing sodium were found, or a slight tendency towards its elevation. In cases of adrenal hypertension (Conn's syndrome, pheochromocytoma) the level of total metabolizing sodium is significantly elevated. No correlation was seen between the levels of total metabolizing sodium, and plasma and erythrocytes sodium. The decrease of total metabolizing sodium at early stages of essential hypertension must be an adaptative reaction of the body, which is proved by the increased urine excretion of sodium.