Septic Disease Research Articles

Omega-3 fatty acids and liver disease

Omega-3 fatty acids and liver disease

Longitudinal increases in mitochondrial DNA levels in blood cells are associated with survival in critically ill patients

BackgroundMitochondrial dysfunction may be causally related to the pathogenesis of organ failure in critically ill patients. Decreased mitochondrial DNA (mtDNA) levels have been associated with mitochondrial dysfunction and were investigated here in relation to short-term (31-day) survival.MethodsThis was a prospective longitudinal cohort study of 28 mechanically ventilated critically ill adults admitted to a single center tertiary care intensive care unit (ICU) with hypotension secondary to cardiogenic (N = 13), septic (N = 14) or hypovolemic (N = 1) disease processes. Clinical data and blood were collected at baseline and patients were followed until they expired or left the ICU. Blood was collected every Monday, Wednesday and Friday, and the buffycoat relative mtDNA/nuclear DNA (nDNA) ratio was determined. An archived pool of healthy controls was also studied.ResultsAt baseline, the patients' mtDNA/nDNA ratio was 30% lower than a pool of 24 healthy controls (0.76 versus 1.09) and was not different between short-term survivors and non-survivors (0.74 ± 0.05 (N = 16) versus 0.79 ± 0.06 (N = 12), p = 0.49). By day 4, the percent mtDNA/nDNA change from baseline in survivors was significantly different from that in non-survivors (+29.5% versus -5.7%, p = 0.03). It also tended to be higher in survivors at last measurement (+38.4% versus +7.1%, p = 0.06). There was a weak correlation between within patient mtDNA/nDNA and platelet count (r = 0.20, p = 0.03) but not with Sequential Organ Failure Assessment (SOFA) scores (r = 0.12, p = 0.23). The mtDNA associations remained after adjustment for platelet.ConclusionBlood mtDNA levels appeared initially low, increased over time in patients who ultimately survived, and remained low in those who did not. This is consistent with mitochondrial recovery being associated with survival and warrants further investigation as a marker of mitochondrial alterations and outcome in critical illness.

Bilateral Sequential Lung Transplantation

Bilateral Sequential Lung Transplantation

TLR‐2‐mediated induction of vascular endothelial growth factor (VEGF) in cartilage in septic joint disease

Bacterial arthritis is a progressive joint disease which includes rapid destruction of articular cartilage even after clearance of the causal factor. The resulting post-infectious arthropathy is mainly characterized by self-perpetuating joint destruction and extensive angiogenesis in the emerging pannus-like synovial membrane, but the underlying molecular mechanisms of the bacteria-initiated process remain incompletely understood. This study was conducted to elucidate the expression and regulation of angiogenic and cartilage-destructive vascular endothelial growth factor (VEGF) in septic arthritis. For that purpose, aspirates of synovial fluid from patients with pyogenic arthritis were examined for VEGF levels by ELISA. In vitro studies with primary and immortalized chondrocytes were performed to determine whether Gram-positive and Gram-negative bacteria induce VEGF expression, by using real-time RT-PCR, ELISA, and immunohistochemistry. Activation of the transcription factor AP-1 was assessed by EMSA experiments. The necessity of the Toll-like receptor-2 (TLR-2), ERK-1/-2, and AP-1 pathway for infectious VEGF induction in chondrocytes was examined by using specific blocking reagents. ELISA experiments revealed that aspirates of synovial fluid from patients with pyogenic arthritis contain elevated levels of VEGF. The in vitro results confirmed the transcriptional induction of VEGF in chondrocytes after bacterial challenge by real-time RT-PCR, ELISA, and immunohistochemistry. This activation was mediated by a TLR-2-, ERK-1/-2-, and AP-1-dependent pathway. The findings demonstrate the expression of Toll-like receptors on mesenchymal articular chondrocytes and reveal TLR-2-mediated VEGF induction in human chondrocytes after Gram-positive bacterial sensing. Since VEGF is a potent angiogenic and tissue remodelling factor, evidence that Toll-like receptors contribute to destructive arthropathy after microbial joint infection is provided. VEGF may be a therapeutic target in the future for the prevention of post-infectious cartilage degradation in articular joints.

Role of the factor V Leiden mutation in septic peritonitis assessed in factor V Leiden transgenic mice*

The factor V Leiden (FVL) mutation (Arg506Glu) results in the production of an FV protein that when activated is relatively resistant to inactivation by activated protein C and thereby leads to predisposition to thrombosis. The rather high prevalence of the FVL mutation in the general population prompted speculation about a potential survival benefit for individuals carrying the FVL allele. Indeed, both clinical and experimental animal data suggest that a heterozygous FVL genotype might protect against the lethal consequences of sepsis. We sought to confirm the survival advantage of heterozygous FVL mice in septic disease. Controlled animal experiment. Academic research laboratory. Wild-type, heterozygous, and homozygous FVL mice subjected to 1 x 10 live bacteria as model for septic peritonitis. None. The intraperitoneal injection of E. coli led to growth and dissemination of bacteria and provoked an inflammatory response as evident from elevated cytokine levels (interleukin-6, interleukin-10, and tumor necrosis factor-alpha), induced thrombin-antithrombin complex levels, increased granulocyte influx into the peritoneal cavity, liver necrosis, and adhesion of leukocytes to the vessel wall, resulting in approximately 50% mortality after 72 hrs. The FVL genotype had no significant effect on bacterial outgrowth, markers of inflammation (i.e., tumor necrosis factor-alpha levels of 152 [96.2-200], 152 [99.7-1745], and 110 [99.7-177] pg/mL in peritoneal lavage fluid at t = 20 hrs for wild-type, heterozygous, and homozygous FVL mice, respectively), thrombin generation (i.e., thrombin-antithrombin complex levels of 19.9 [9.31-37.4], 10.4 [6.55-15.8], and 12.6 [8.24-29.0] ng/mL in peritoneal lavage fluid at t = 6 hrs for wild-type, heterozygous, and homozygous FVL mice, respectively), and/or survival (50%, 36%, and 50% for wild-type, heterozygous, and homozygous FVL mice, respectively). The FVL allele has no beneficial effect in mouse septic peritonitis, and the general protective effect of FVL in sepsis needs further investigation.

Relapsing Fever SpirochetesBorrelia recurrentisandB. duttoniiAcquire Complement Regulators C4b-Binding Protein and Factor H

Relapsing fever is a rapidly progressive and severe septic disease caused by certain Borrelia spirochetes. The disease is divided into two forms, i.e., epidemic relapsing fever, caused by Borrelia recurrentis and transmitted by lice, and the endemic form, caused by several Borrelia species, such as B. duttonii, and transmitted by soft-bodied ticks. The spirochetes enter the bloodstream by the vector bite and live persistently in plasma even after the development of specific antibodies. This leads to fever relapses and high mortality and clearly indicates that the Borrelia organisms utilize effective immune evasion strategies. In this study, we show that the epidemic relapsing fever pathogen B. recurrentis and an endemic relapsing fever pathogen, B. duttonii, are serum resistant, i.e., resistant to complement in vitro. They acquire the host alternative complement pathway regulator factor H on their surfaces in a similar way to that of the less serum-resistant Lyme disease pathogen, B. burgdorferi sensu stricto. More importantly, the relapsing fever spirochetes specifically bind host C4b-binding protein, a major regulator of the antibody-mediated classical complement pathway. Both complement regulators retained their functional activities when bound to the surfaces of the spirochetes. In conclusion, this is the first report of complement evasion by Borrelia recurrentis and B. duttonii and the first report showing capture of C4b-binding protein by spirochetes.

Pictorial Essay: Multinodular Disease

The evaluation of patients presenting with multinodular pulmonary disease provides an important clinical challenge for physicians. The differential diagnosis includes an extensive list of benign and malignant processes making the management of these cases frequently problematic. With the introduction of high-resolution CT (HRCT) scanning, the ability to assess various patterns of diffuse multinodular disease has evolved into an essential part of the diagnostic process. The purpose of this article is to develop an approach to the diagnosis of multinodular parenchymal disease using HRCT scan pattern recognition as a point of departure.

Nocturnal melatonin concentration is correlated with illness severity in patients with septic disease

Nocturnal melatonin concentration is correlated with illness severity in patients with septic disease

Descending necrotizing mediastinitis

[corrected] Descending necrotizing mediastinitis (DNM) is an acute, serious, septic disease which results from a complication of oropharyngeal infection. The disease requires a prompt diagnosis and radical surgical treatment to reduce high mortality (40%). The optimal form of mediastinal drainage remains conroversial. The reason for publishing this report is both the fact that DNM is very rare and our experience prefering thoracotomy as an optimal approach to treating the disease. We reported a 34-years-old woman with DNM. The disease began as a peritonsillar abscess. After a bilateral double pleural drainage the disease worsened. In order to achieve radical mediastinal debridement and drainage, we carried out posterolateral right thoracotomy. We also had to perform left thoracotomy bacause of massive bleeding coused by septic erosion. There were no more reoperations. Aggressive surgical treatment, regardless the localization and the extent of changes is the key to success in the treatment of patients with necrotizing mediastinitis.

Anaplasma and Ehrlichia Infection

Human and animal infections by Anaplasmataceae are increasingly recognized as important and potentially fatal arthropod-transmitted diseases. Since the first recognition and implementation of diagnostic methods for human infection by Ehrlichia chaffeensis and Anaplasma phagocytophilum, the incidence of infections has linearly increased. Moreover, diagnostic and epidemiological testing indicates that "ehrlichia" infections are globally distributed and suggests that additional agents of human and veterinary "ehrlichiosis" will be identified. With increasing disease identification has come recognition that the infections can be severe, with approximately one-half of patients requiring hospitalization for complications including respiratory distress, myocarditis, neurological complications, hepatitis, a septic or toxic shock-like disease, opportunistic infections, and death in 0.5 to 3.0%. An understanding of the diseases, pathophysiology, pathogenesis, control, and management will best be developed through fundamental investigations. Advances in comprehension as to the separate contributions of bacteria and host are crucial since most data now suggest that alterations in host neutrophil function and protection from innate and adaptive immunity also contribute to disease manifestations. It is reasonable to operate from the hypothesis that these host cell functional changes ultimately benefit bacterial survival while inadvertently eliciting clinical disease in poorly adapted hosts. A firmer basis for the scientific understanding of Anaplasmataceae biology will allow logical and rational approaches toward infection control, prevention, and treatment.

387 Anemia and Elevated C-Reactive Protein in Premature Low Birth Weight Infants as Predictors of Positive Blood Cultures

Background Infection remains a significant cause of morbidity in neonatal intensive care. Differentiation between sepsis and clinical deterioration from other causes is difficult. It would be of great value if quick and simple laboratory data support evidence of septic disease. Aim Commonly available laboratory data (Hemoglobin (Hb), white blood cell count (WBC) and C-Reactive Protein (CRP) were analysed for their reliability in predicting disease of infectious origin in newborns admitted to a neonatal intensive care unit (NICU). Results 102 hospitalised newborns were analysed during a 3-months' study period. 81 newborns had one or more episodes of suspected sepsis and antibiotics were started 105 times. In 17 (20%) out of 85 obtained bloodcultures an organism was isolated. Newborns with lower birth weight and gestational age were more likely to have a positive bloodculture (1430 g vs 2070 g and 30 weeks vs 32.5 weeks, both p<0.01). Hb was significantly lower (7.9 vs 9.6 mmol/L, p<0.01), and the CRP higher (26 vs 8 mg/L, p<0.001) in newborns with a positive blood culture. WBC was similar in both groups. A CRP > 20 mg/l was 94% specific for a positive blood culture. In combination with a low Hb (< 8 mmol/L) or low WBC (< 8), specificity increased to 98% and 100%. Corresponding sensitivities were low (35%). Subset analysis in newborns with late onset sepsis showed no significant differences in CRP, Hb or WBC due to the small number of patients (n=13 and n=15). The specificity of CRP > 20 mg/l persisted (93%) and increased to 100% in combination low WBC. Low Hb had no more additive effect (specificity stayed 93%). Conclusion A low Hb and/or low WBC with an elevated CRP are highly specific for a positive blood culture in premature low birth weight infants. In case of late onset sepsis the Hb is not discriminating.

Activation-Induced Depletion of Protein Kinase Cα Provokes Desensitization of Monocytes/Macrophages in Sepsis

Sepsis accounts for the majority of fatal casualties in critically ill patients, because extensive research failed to significantly improve appropriate therapy strategies. Thus, understanding molecular mechanisms initiating the septic phenotype is important. Symptoms of septic disease are often associated with monocyte/macrophage desensitization. In this study, we provide evidence that a desensitized cellular phenotype is characterized by an attenuated oxidative burst. Inhibition of the oxidative burst and depletion of protein kinase C alpha (PKC alpha) were correlated in septic patients. To prove that PKC alpha down-regulation indeed attenuated the oxidative burst, we set up a cell culture model to mimic desensitized monocytes/macrophages. We show that LPS/IFN-gamma-treatment of RAW264.7 and U937 cells lowered PKC alpha expression and went on to confirm these data in primary human monocyte-derived macrophages. To establish a role of PKC alpha in cellular desensitization, we overexpressed PKC alpha in RAW264.7 and U937 cells and tested for phorbolester-elicited superoxide formation following LPS/IFN-gamma-pretreatment. Inhibition of the oxidative burst, i.e., cellular desensitization, was clearly reversed in cells overexpressing PKC alpha, pointing to PKC alpha as the major transmitter in eliciting the oxidative burst in monocytes/macrophages. However, PKC alpha inactivation by transfecting a catalytically inactive PKC alpha mutant attenuated superoxide formation. We suggest that depletion of PKC alpha in monocytes from septic patients contributes to cellular desensitization, giving rise to clinical symptoms of sepsis.

Inibição da formação de abscesso abdominal em rato: mortalidade por sepse

Intra-abdominal abscesses and adhesions play important roles on isolation of a septic process and on organism protection against bacteremia. On the other hand, such phenomenon difficults the afflux of immune factors and antibiotics to the septic site. The purpose of the present study was to evaluate the effect of abscess inhibition on survival of abdominal sepsis. Thirty adult Wistar rats were submitted to intraperitoneal injection of 50% rat feces solution. The animals were divided into three groups (n = 10). Group 1: control - feces solution; group 2: feces solution plus 0.9% saline solution; and group 3: feces solution plus 1% carboxymethylcellulose to inhibit abdominal adhesions. The three groups were divided into two subgroups (n = 5). Subgroup A: relaparorotomy after 4 days and investigation of the abdominal cavity; and subgroup B: follow-up during 30 days to evaluate the mortality and its cause. The Fisher test was utilized for statistical analyses. The injection of 0.9% saline solution did not increase the mortality of the rats. However, the mortality enhanced in the group that received carboxymethylcellulose comparing with control group. That group developed less adhesions and abscesses. This study demonstrated that the reduction of abscess formation and of intraperitoneal adhesions increases the mortality due to abdominal septic disease.

Características clínicas de los niños hospitalizados por infección por virus Influenza

The clinical manifestations of influenza virus are fairly nonspecific and are similar to those of other viral infections, respiratory processes due to other causes and even septic disease in neonates. Few studies have been performed of the clinical characteristics of influenza virus infection in hospitalized children. To evaluate the clinical characteristics of children hospitalized for influenza virus infection in four consecutive epidemic waves (2000-2004). We retrospectively reviewed the medical records of children hospitalized for influenza A and B virus infection confirmed by cell culture and polymerase chain reaction. Age, sex, symptoms on admission, complementary investigations, diagnosis and outcome were evaluated. Eighty-four children were hospitalized, of which 74 had influenza virus type AH3, five had influenza virus type AH1 and five had influenza B virus. A total of 42.8 % were aged less than 6 months. The main symptoms were fever (75 patients), cough (56 patients) and ENT involvement (53 patients). The most frequent causes of admission were febrile syndrome (75 patients), bronchiolitis (19 patients), pneumonia (13 patients) and bronchitis (8 patients). In 21 patients viral or bacterial coinfection was found, the most frequent of which was respiratory syncytial virus (10 patients). Few differences were found among age groups except for pneumonia and prolonged fever (more frequent in children older than 6 months) and lymphocytosis (in children younger than 6 months). The greatest number of complementary investigations in younger children was performed for acute febrile syndrome in neonates aged less than 6 months. Risk factors for hospitalization were found in only three children, all of whom were older than 6 months. Outcome was favorable in all children. Influenza virus infection in hospitalized children is most frequent in previously healthy neonates with fever and nonspecific signs and symptoms that are similar to those of other infectious processes. Specific microbiological diagnostic techniques are required for an early diagnosis. Healthy infants aged less than 24 months are most at risk for hospitalization for influenza virus infection.

Open-label simultaneous radio-chemotherapy of glioblastoma multiforme with topotecan in adults

Background: Due to its radioresistance, the prognosis of glioblastoma multiforme (GBM) remains poor. Therefore, we investigated the impact of simultaneous radio-chemotherapy with topotecan (Hycamtin ®) on clinical outcome, tolerability and quality of life. Patients and methods: In this multicenter trial, 60 patients (19 females, 41 males) with histologically proven (5× biopsy, 31× subtotal resection, 24× total resection) GBM were included. Radio-Chemotherapy was performed with daily doses of 2.0 Gy (total, 60 Gy), and 0.5 mg (absolute dose) of topotecan intravenously 1 h prior to irradiation. Toxicity was assessed using common toxicity criteria (CTC). General condition and quality of life were assessed at baseline, at the end of therapy, and 6 weeks post-therapy. Local control and length of survival were compared with an historical control group of 67 patients only treated with postoperative radiotherapy following stereotactic biopsy (15×), subtotal resection (39×), or total resection (13×). Results: 57 patients completed the therapy. Median radiation dose was 60 Gy (range 16–76 Gy). Median cumulative topotecan dose was 15 mg (range 7.5–18.5 mg). CTC toxicity grade 3 was observed in six patients and grade 4 toxicity in two patients (three events). Two patients died of septic disease. Mean Karnofsky index was 87% at baseline, 81% at the end of therapy, and 80% at 6 weeks post-therapy. Median survival time was 15 months, significantly longer than the 11 months seen in the control group ( P < 0.002). Extent of tumour resection or patient age did not have a significant effect on survival. Conclusion: This multimodal approach is well tolerated, and quality of life remains preserved. The relatively long median survival time is promising but a further randomised double blind placebo controlled parallel designed clinical trial should be performed to confirm these results.

Données actuelles sur les prélèvements de granulocytes

Granulocyte transfusion is uncommon but essential for some aplastic patients with major infection and those with septic granulomatosis disease and visceral aspergillosis. Compatibility between donor and recipient (ABO, D, Kell blood type, cytomegalovirus) is necessary. Stimulation by dexamethasone, before use of GCSF, permits to obtain approximately 10 × 10 9 white cells per l. Doses of heparin must be calculated to ensure an efficient hypocoagulation without any trouble for the donor immediately after his donation. Sedimentation by hydroxyethylstarch is an unavoidable element to obtain the most efficient separation of granulocytes. Most donations present an amount of white cells between 2 and 4 10 × 10 10. This enables to transfuse efficiently children and adults.

Streptococcus iniae type II infections in rainbow trout Oncorhynchus mykiss

Clinical and pathological findings (anorexia, hemorrhage, lethargy, loss of orientation and exophthalmia) indicated that Streptococcus iniae type II is responsible for a fatal disease in rainbow trout. Histopathological findings revealed that S. iniae type II produces a systemic disease, including a diffuse necrotizing myositis. The distribution of viable bacteria in infected tissues substantiated the pathological findings, confirming that S. iniae type II is responsible for a generalized septic disease of rainbow trout.

Trojan horse effect: phagocyte-mediated Streptococcus iniae infection of fish.

The salmonid macrophage-like cell line RTS-11 and purified trout pronephros phagocytes were used to analyze in vitro entry and survival of two Streptococcus iniae serotypes. Efficient invasion by S. iniae occurred in both cells, but only the type II strain persisted in pronephros phagocytes for at least 48 h. Ex vivo models of opsonin-dependent phagocytosis by pronephros phagocytes demonstrated increased phagocytosis efficacy. Analysis of phagocytes collected from diseased fish demonstrated that approximately 70% of the bacteria contained in the blood during the septic phase of the disease were located within phagocytes, suggesting an in vivo intracellular lifestyle. In addition to the augmented levels of bacteremia and enhanced survival within phagocytes, S. iniae type II induces considerable apoptosis of phagocytes. These variabilities in intramacrophage lifestyle might explain differences in the outcomes of infections caused by different serotypes. The generalized septic disease associated with serotype II strains is linked not only to the ability to enter and multiply within macrophages but also to the ability to cause considerable death of macrophages via apoptotic processes, leading to a highly virulent infection. We assume that the phenomenon of survival within phagocytes coupled to their apoptosis plays a crucial role in S. iniae infection. In addition, it may provide the pathogen an efficient mechanism of translocation into the central nervous system.

A comparison of foal and adult horse neutrophil function using flow cytometric techniques

Flow cytometric assays were used to compare phagocytic and oxidative burst activity of neutrophils from healthy foals less than 7 days of age with the activity of cells from healthy adult horses. The phagocytosis of Staphylococcus aureus by foal neutrophils was less than that observed for adult neutrophils when autologous serum was used as the source of opsonins in the assay. The use of adult serum did not significantly improve the ability of foal neutrophils to attach bacteria. The oxidative burst activity of foal neutrophils was equivalent to that of adult cells. However, when serum or plasma was incorporated into the oxidative burst assay, foal neutrophils demonstrated greatly reduced autofluorescence and a suppressed response to phorbol myristate acetate (PMA), relative to that demonstrated by adult cells. These results suggest that peripheral blood neutrophils from foals have a reduced ability to phagocytose bacteria relative to that exhibited by adult horse neutrophils and that the oxidative burst activity of foal neutrophils is down-regulated in response to an unidentified serum factor(s). Such changes may contribute to the increased susceptibility of foals to septic disease.

Measurement of cartilage oligomeric matrix protein (COMP) in normal and diseased equine synovial fluids

Objective This study was designed to assay cartilage oligomeric matrix protein (COMP) in equine synovial fluids and to compare the concentration in synovial fluids from normal horses with joint diseased horses. The relationship between the COMP degradation and the matrix metalloproteinase activity in synovial fluids was also investigated.Design Using COMP antigen prepared from equine articular cartilage and murine monoclonal antibody (12C4) raised against human COMP, an inhibition ELISA was developed. COMP in equine synovial fluids from normal and diseased joints was quantified. Metalloproteinase activities were evaluated in the same synovial fluids by a gelatin degradation ELISA. COMP fragments were evaluated qualitatively by Western blotting.Results The COMP inhibition ELISA was reliable at concentrations of equine COMP between 62.5 and 2000ng/ml. COMP values in joint fluids in both aseptic and septic joint disease (19.7±15.3 and 16.1±11.2μg/ml, respectively) were significantly (P< 0.001) lower than normal (53.2±29.0μg/ml). The molecular sizes of COMP on immunoblots were different between normal and diseased synovial fluids; more fragments were seen in diseased fluids. The aseptic (26.6±20.6%) and septic joint disease synovial fluids (36.1±37.5%) had significantly higher (P< 0.02 and 0.002, respectively) gelatinolytic activities than normal (13.6±13.7%). There was a negative correlation (R=−0.31, P< 0.002) between COMP level and gelatinase activity.Conclusions We conclude that the fragment pattern and the absolute COMP concentration maybe useful for monitoring joint disease, and that COMP degradation in synovial fluids from progressed joint disease may be due to MMP gelatinolytic activity.