Usefulness of 1,3 Beta-D-Glucan Detection in non-HIV Immunocompromised Mechanical Ventilated Critically Ill Patients with ARDS and Suspected Pneumocystis jirovecii Pneumonia

INTRODUCTION

Pneumocystis jirovecii pneumonia (PCP) is a major cause of disease in immunocompromised individuals. Diagnosis is typically obtained by microscopy and/or PCR. For ambiguous PCR results, we evaluated the new biomarker 1,3-Beta-D-Glucan (BDG).

METHODS

BDG serum levels were assessed and correlated to PCR results in immunosuppressed patients with ARDS.

RESULTS

11 (22%) out of 50 patients had suspected PCP. APACHE II (26 vs. 24; p < 0.002), SOFA score (16 vs. 14; p < 0.010) and mortality rate (34 vs. 69% p < 0.004; 34 vs. 80% p < 0.003) were significantly altered in patients with positive (pPCR) and slightly positive (spPCR) PCJ PCR as compared to patients with no-PCP (nPCP). BDG levels were significantly lower in patients with nPCP (86; 30-315 pg/ml) than in patients with pPCR (589; 356-1000 pg/ml; p < 0.001) and spPCP (398; 297-516 pg/ml; p < 0.004) referring to the cutoff in this study for PCP of 275 pg/ml. An overall sensitivity (S) of 92% (95% CI 86-96%) and specificity (SP) of 84% (95% CI 79-85%) for PCP were found for the BDG Fungitell assay. In detail, S of 98% (95% CI 94-100%) and SP of 86% (95% CI 82-92%) for pPCP and S of 98% (95% CI 96-100%) and SP of 88% (95% CI 86-96%) for spPCO were found.

CONCLUSION

Serum BDG levels were strongly elevated in PCP, and the negative predictive value is high. BDG could be used as a preliminary test for patients with suspected PCP, especially in patients with slightly positive PCR results.

Demography, maternal health and the epidemiology of malaria and other major infectious diseases in the rural department Tsamba-Magotsi, Ngounie Province, in central African Gabon

BACKGROUND

Sub-Saharan Africa is undergoing an epidemiological transition from a predominance of infectious diseases to non-communicable and lifestyle related conditions. However, the pace of this transition and the pattern of disease epidemiology are uneven between affluent urban and rural poor populations. To address this question for a remote rural region located in the central African rainforest region of Gabon, this study was conducted to assess reasons for health care attendance and to characterize the epidemiology of malaria and other major infectious diseases for the department of Tsamba Magotsi.

METHODS

Major causes for health care attendance were collected from local hospital records. Cross sectional population based surveys were performed for the assessment of local malaria epidemiology. Pregnant women attending antenatal care services were surveyed as a sentinel population for the characterization of chronic viral and parasitic infections in the community.

RESULTS

Infectious diseases were responsible for 71% (7469) of a total of 10,580 consultations at the formal health care sector in 2010. Overall, malaria - defined by clinical syndrome - remained the most frequent cause for health care attendance. A cross sectional malaria survey in 840 asymptomatic individuals residing in Tsamba Magotsi resulted in a Plasmodium spp. infection prevalence of 37%. The infection rate in 2-10 year old asymptomatic children - a standard measure for malaria endemicity - was 46% (100 of 217) with P. falciparum as predominant species (79%). Infection with other plasmodial species (P. ovale and P. malariae) presented most commonly as coinfections (23.2%). Prevalence of HIV, HBV, and syphilis were 6.2, 7.3, and 2.5%, respectively, in cross-sectional assessments of antenatal care visits of pregnant women. Urogenital schistosomiasis and the filarial pathogens Loa loa and Mansonella perstans are highly prevalent chronic parasitic infections affecting the local population.

CONCLUSIONS

Despite major improvements in the accessibility of Tsamba Magotsi over the past decade the epidemiological transition does not appear to have majorly changed on the spectrum of diseases in this rural Gabonese population. The high prevalence of Plasmodium infection indicates a high burden of malaria related morbidity. Infectious diseases remain one of the most important health issues and further research activities in the field of tropical medicine and infectious diseases could help improve health care for the local population.

Ischaemic stroke and Clostridium septicum sepsis and meningitis in a patient with occult colon carcinoma - a case report and review of the literature

Background

Clostridium septicum is a rare cause of meningitis and brain abscess in children and adults. Gas production by the pathogen can lead to pneumocephalus and the overall mortality rate of Clostridium septicum CNS infection is as high as 74%. The most common entry site of the pathogen is the gastrointestinal tract.

Case presentation

We describe a 74-year-old man who presented with a left-sided cerebral infarction in the middle cerebral artery territory. In addition the patient showed signs of Systemic Inflammatory Response Syndrome and Disseminated Intravascular Coagulation. Examination of blood cultures and cerebrospinal fluid led to the diagnosis of sepsis and meningitis caused by Clostridium septicum. Despite appropriate antibiotic therapy the condition of the patient deteriorated rapidly and he died on day 2 after admission. Autopsy revealed a previously unknown adenocarcinoma of the colon ascendens as entry site of the pathogen.

Conclusion

Clostridium septicum should be considered as potential pathogen in patients with sepsis and meningitis. Gram stain morphology in conjunction with severe sepsis can rapidly point into the direction of this pathogen. CNS infections manifest either as meningoencephalitis/cerebritis or as brain abscess. Entry site of the pathogen is almost uniquely the gastrointestinal tract. In adults more than 50% suffer from colorectal carcinoma, therefore survivors of Clostridium septicum infections should be examined for underlying occult colorectal malignancy.

Usage of 1,3-β-D-Glucan for Early Detection of Invasive Mycoses and Outcome Parameter in Immunocompromised Critically Ill Patients

INTRODUCTION

Invasive fungal disease (IFD) remains a significant cause of morbidity and mortality in critically ill patients.

METHODS

Examination of 1,3-β-D-glucan (BDG) for IFD and as outcome parameter in immunocompromised critically ill patients with septic shock.

RESULTS

Thirty-two (69 %) out of 46 included patients had BDG beyond the cutoff of >80 pg/ml (mean 320 pg/ml). Twelve (37 %) had findings of Aspergillus spp. in BAL (mean BDG 413 pg/ml). EORTC/MSG guidelines classified these as probable invasive aspergillosis (IA)/IFD. Five (16 %) had candidaemia (mean BDG level 361 pg/ml). Sensitivity of 78 % (95 % CI 58-88 %) and specificity of 68 % (95 % CI 52-77 %) for IFD were found on the BDG Fungitell assay. In detail, a sensitivity of 73 % (95 % 58-84 %) and specificity of 83 % (95 % CI 68-93 %) for IA and a sensitivity of 77 % (CI 95 % 62-87 %) and specificity 53 % (95 % CI 37-73 %) for candidaemia were found. APACHE II, SOFA score and mortality rate were in the elevated BDG group significantly altered (26 vs. 21, p < 0.003; 15 vs. 13, p < 0.006; 72 vs. 50 %, p < 0.004).

CONCLUSION

1,3-β-D-glucan assay is helpful for early detection of IFD; moreover, elevated BDG levels can be used as a predictor for outcome in immunocompromised critically ill patients as presented in our study.

Comparison of 1,3-β-d-glucan with galactomannan in serum and bronchoalveolar fluid for the detection of Aspergillus species in immunosuppressed mechanical ventilated critically ill patients

PURPOSE

Invasive pulmonary aspergillosis (IPA) is an important cause of morbidity/mortality in immunocompromised critically ill patients. New diagnostic strategies for early detection of IPA include the noninvasive biomarkers 1,3-β-d-glucan (BDG), serum, and bronchoalveolar (BAL) fluid galactomannan (GM). The aim of this study was to compare these markers for early detection of IPA in immunosuppressed critically ill patients.

METHODS

Between December 2014 and December 2015, 49 immunosuppressed patients with respiratory failure were treated at our intensive care unit (ICU). We compared the BDG Fungitell assay with GM Platelia assay in serum and BAL for early detection of IPA. All tests were performed initially after admission at the ICU.

RESULTS

In our study with 49 patients, 13 (26%) had probable IPA. These patients had a higher Acute Physiology And Chronic Health Evaluation II score (28 vs 23, P<.001), Sequential Organ Failure Assessment score (16 vs 14, P<.001), more neutropenia (77% vs 30%, P<.001), worse Horowitz Index (99 vs 73 P<.020), a longer ICU stay (26 vs 17 days, P<.044), and a higher mortality rate (77% vs 58%, P<.001) as compared with patients without probable IPA. The used biomarker BDG presented in patients with probable IPA showed significantly higher levels as compared with patients without probable IPA (375 [103-1000 pg/mL; P<.001] vs 64 [30-105 pg/mL; P < .001]). Comparison of BDG with GM showed that positive serum GM could be detected in only 4 (30%), whereas positive BAL GM could be detected in 12 (92%; mean optical density index, 3.7) of 13 probable IPA cases. These results can be expressed as an overall sensitivity of 88% and a specificity of 82% for probable IPA using the BDG Fungitell assay, a sensitivity of 35% and a specificity of 70% using the serum GM Platelia assay, and a sensitivity of 70% and a specificity of 94% using the BAL GM Platelia assay. The negative predictive values of the used tests were 94% for the BDG Fungitell assay, 94% for the serum GM Platelia assay, and 90% for the BAL GM Platelia assay.

CONCLUSION

1,3-β-d-Glucan may be a useful marker for patients under surveillance at risk for IPA. In critically ill patients with immunosuppression, early diagnosis of IPA may be improved by BDG as compared with serum GM. However, diagnostic performance and accuracy increase when BDG is run in parallel with GM from BAL; moreover, the association of the 2 parameters has also the advantage of detecting early and reliable IPA.

Rewarding feedback promotes motor skill consolidation via striatal activity

Knowledge of performance can activate the striatum, a key region of the reward system and highly relevant for motivated behavior. Using functional magnetic resonance imaging, striatal activity linked to knowledge of performance was measured during the training of a repetitive arc-tracking task. Knowledge of performance was given after a random selection of trials or after good performance. The third group received knowledge of performance after good performance plus a monetary reward. Skill learning was measured from pre- to post- (acquisition) and from post- to 24h posttraining (consolidation). Our results demonstrate an influence of feedback on motor skill learning. Adding a monetary reward after good performance leads to better consolidation and higher ventral striatal activation than knowledge of performance alone. In turn, rewarding strategies that increase ventral striatal response during training of a motor skill may be utilized to improve skill consolidation.

[Performance Indicators of Hospitals in One Region Between 2006/07 and 2013: a Trend Analysis]

BACKGROUND

In spite of a nationwide implementation of performance indicators (PI) for monitoring inpatient medical care, a systematic evaluation of their development over time is still missing.

METHODS

A trend analysis of annual rates of PI from 2006/07 to 2013 of Bavarian hospitals was conducted; 123 out of a total of 245 PI selected from 15 distinct clinical fields were available and comparable over the entire period and evaluated. Joinpoint regression was used to estimate annual percentage changes (APC) in regional averages. Individual hospital rates were inspected with box plots for selected indicators.

RESULTS

99 PI (80.5%) showed improvement over time, 67 (54.5% of all PI) were statistically significant. A change from positive to negative trend was found in 15 indicators (12.2%); the negative trend was significant only once. A continuous negative trend was observed in 9 cases (7.3%) (3 significant). Extreme values of hospital rates were present throughout the entire period of observation with results generally far below the national average.

CONCLUSION

The majority of indicators improved continuously, which may be interpreted as indicating effectiveness of quality assurance programs, and could also give a strong impetus to further quality improvement measures.

Overwhelming Postsplenectomy Infection: A Prospective Multicenter Cohort Study

BACKGROUND

Recent population-based cohort studies have questioned the role of pneumococci as the most frequent pathogen causing severe infection in patients after splenectomy. The aim of the study was to define the causative pathogens and clinical presentation of patients with overwhelming postsplenectomy infection (OPSI).

METHODS

In a prospective cohort study in 173 German intensive care units, we searched for patients with and without asplenia and community-acquired severe sepsis/septic shock. Clinical and laboratory variables and survival of patients were assessed.

RESULTS

Fifty-two patients with severe sepsis or septic shock with asplenia and 52 without asplenia were included. OPSI patients more often had a history of malignancy (38% vs 17%; P = .016) and had a lower body mass index (24 kg/m(2) vs 28 kg/m(2); P = .004). Streptococcus pneumoniae was detected more frequently in OPSI patients (42% vs 12% without asplenia; P < .001) and more frequently manifested as bloodstream infection (31% vs 6%; P = .002). Gram-negative infection was similar in both groups (12% vs 19%; P = .157). Pneumococcal vaccine coverage of OPSI patients was low overall (42% vs 8% among patients without asplenia; P < .001). Purpura fulminans was a frequent complication, developing in 19% of OPSI patients vs 5% of patients without asplenia (P = .038). The interval between splenectomy and OPSI was 6 years (range, 1 month-50 years). On multivariable Poisson regression, asplenia was the only predictive variable independently associated with pneumococcal sepsis (adjusted relative risk, 2.53 [95% confidence interval, 1.06-6.08]).

CONCLUSIONS

Pneumococcal infections remain the most important cause of severe sepsis and septic shock following splenectomy.

Human case of Onchocerca lupi infection, Germany, August 2014

Onchocerca lupi, a nematode parasite infecting dogs and cats with a hitherto unknown arthropod vector, is also being recognised as a parasite also responsible for human eye infections. Here we describe a case of human eye infection diagnosed molecularly by nematode 12S rDNA PCR in a German patient who had travelled to Tunisia and Turkey. The patient recovered after treatment with antibiotic and anti-inflammatory therapy.

Primary cutaneous cryptococcosis in an eight-year-old immunocompetent child: how to treat?

Here we report on a case of primary cryptococcal skin infection in an immunocompetent 8-year-old boy. The infection first manifested itself as a subcutaneous abscess around the proximal joint of his right thumb after a minor injury from contact with a thorny shrub. After surgical incision and drainage was performed, Cryptococcus neoformans var. neoformans was the only pathogen cultured from the lesion. An agglutination test for the capsular antigen in serum displayed negative results and the immunological work-up revealed no underlying immunodeficiency. A "watch and wait" strategy - one without systemic antifungal treatment - was adopted and this resulted in uneventful healing. In summary, primary cryptococcal skin infections in immunocompetent hosts may be managed successfully by surgical treatment in combination with careful clinical follow-up. This approach may help avoid unnecessary antimicrobial treatments.

Purulent pericarditis and pneumonia caused by Streptococcus equi subsp. zooepidemicus

Purulent pericarditis is a life-threatening disease that usually manifests following bacteraemia or through spreading from an intrathoracic focus. Only a few cases of this disease have been reported with Lancefield group C streptococci as aetiological agents, and the primary focus in these infections remains unknown. We report a case of purulent pericarditis with septic and cardiogenic shock, caused by Streptococcus equi subsp. zooepidemicus (group C) in a 51-year-old patient. The pathogen was possibly contracted through contact with horses. Most probably, it caused initially pneumonia before spreading to the pericardium, either directly or via the bloodstream. A combined therapeutic approach, consisting of antibiotic therapy and repeated pericardial drainage, was necessary to ensure a clinical cure. After discharge, long-term follow-up for development of constrictive pericarditis is considered mandatory.

Prolonged polyarthralgia in a German traveller with Mayaro virus infection without inflammatory correlates

Background

Mayaro virus is endemic in South America and sporadic outbreaks have been described. It causes a dengue-like febrile illness accompanied by severe and long-lasting polyarthralgias. Outside endemic regions, however, the disease is not well known and can be misdiagnosed as dengue. International travellers are at risk to acquire Mayaro virus and due to increased worldwide travel infectious disease specialists need to be aware of such rare clinical entities.

Case presentation

We report the first Mayaro virus infection imported into Germany. A 20-year-old woman developed fever, myalgia, maculopapular rash, and polyarthralgias following a 10-day trip in the Rurrenabaque region of Bolivia. Severe polyarthralgias persisted for 5 months and were treated with non-steroidal anti-inflammatory drugs. Serological analysis demonstrated Mayaro virus-specific-IgM and -IgG antibodies two months after onset of symptoms. Except for CXCL8/IL-8 other proinflammatory chemokines and cytokines were unremarkable at this time.

Conclusions

Dissemination of knowledge on rare disease might improve patient management. Understanding the inherent features of Mayaro virus infection and how the virus interacts with its host are essential for optimal patient care and therapy.

FIB preparation and SEM investigations for three-dimensional analysis of cell cultures on microneedle arrays

We report the investigation of the interfaces between microneedle arrays and cell cultures in patch-on-chip systems by using Focused Ion Beam (FIB) preparation and Scanning Electron Microscopy (SEM). First, FIB preparations of micro chips are made to determine the size and shape of the designed microneedles. In this essay, we investigate the cell-substrate interaction, especially the cell adhesion, and the microneedle's potential cell penetration. For this purpose, cross-sectional preparation of these hard/soft hybrid structures is performed by the FIB technology. By applying the FIB technology followed by high-resolution imaging with SEM, new insights into the cell-substrate interface can be received. One can clearly distinguish between cells that are only in contact with microneedles and cells that are penetrated by microneedles. A stack of slice images is collected by the application of the slice-and-view setup during FIB preparation and is used for three-dimensional reconstruction of cells and micro-needles.

P1-07-23: Absolute Quantification of Estrogen Receptor alpha in Breast Cancer

Estrogen receptor alpha (ER) is the first biomarker to have been clinically validated as a predictor of cancer therapy response. Measurements of tumor ER expression were based on radiolabeled ligand binding to receptor present in tumor lysates. Despite substantial tissue requirement, lack of specificity for ER isoforms (alpha versus beta) or receptor integrity, quantitative determination of tumor ER content (fmol/mg total protein) was possible. Introduction of anti-ER antibodies later permitted immunohistochemical (***lHC) evaluation of ER expression. IHC determination of ER status in newly diagnosed breast cancer is now a standard of care. While these IHC assays have been shown to be as predictive of endocrine responsiveness as ligand binding assays, they remain semi-quantitative at best reporting tumor ER status either categorically (e.g. + or -) or as a numeric score which is subjective and lacks a linear relationship with endocrine responsiveness. Thus the lack of precision for quantifying ER as a predictive biomarker is one of the most important unresolved issues in breast cancer. We are working to develop a proteomic liquid chromatography-mass spectrometry (LC-MS) assay to help resolve this issue. Samples included recombinant ER (rER), immunoprecipitated (IP) rER, and IP ER from MCF7 cells. ER was digested with trypsin, lyophilised and solubilised in 5 femto-mol/microliter (100 μl) heavy peptide internal standard mix. ER peptides were resolved by LC (100 μl/minute) and detected by selected reaction monitoring MS. The area under the total ion chromatogram for each peptide were used to quantify the amount of analyte present in each sample as a single point reference to the signal of the heavy peptide spike. An 11 point calibration curve (0.1-1000 fmol on column (o/c)) of light peptides with each point in the curve spiked with 100 fmol heavy peptide was also produced to determine assay characteristics such as limits of detection (LOD), limits of quantification (LOQ), linearity, accuracy and precision. Three ER peptides were selected for quantification as they gave the greatest LOD, LOQ, linearity as well as reasonable intra- and inter-assay precision following multiple digestions of rER (intra = 3 digestions in 1 day; inter = 9 digestions over 3 weeks).

Serum (1 → 3)-β-D-glucan measurement as an early indicator of Pneumocystis jirovecii pneumonia and evaluation of its prognostic value

Pneumocystis jirovecii (carinii) pneumonia (PJP) is a major cause of disease in immunocompromised individuals. However, until recently no reliable and specific serological parameters for the diagnosis of PJP have been available. (1 → 3)-β-D-Glucan (BG) is a cell wall component of P. jirovecii and of various other fungi. Data from the past few years have pointed to serum measurement of BG as a promising new tool for the diagnosis of PJP. We therefore conducted a retrospective study on 50 patients with PJP and 50 immunocompromised control patients to evaluate the diagnostic performance of serum BG measurement. Our results show an excellent diagnostic performance with a sensitivity of 98.0% and a specificity of 94%. While the positive predictive value was only 64.7%, the negative predictive value was 99.8% and therefore a negative BG result almost rules out PJP. BG levels were already strongly elevated in an average of 5 days and up to 21 days before microbiological diagnosis demonstrating that the diagnosis could have been confirmed earlier. BG levels at diagnosis and maximum BG levels during follow-up did not correlate with the outcome of patients or with the P. jirovecii burden in the lung as detected by Real-Time PCR. Therefore, absolute BG levels seem to be of no prognostic value. Altogether, BG is a reliable parameter for the diagnosis of PJP and could be used as a preliminary test for patients at risk before a bronchoalveolar lavage is performed.

In vivo anti-malarial effect of the beta-amino alcohol 1t on Plasmodium berghei

Glycerol derivatives are a class of compounds, which are easy and inexpensive to produce with potent anti-malarial activities against blood stages of Plasmodium falciparum in vitro. In the present study, one of these compounds, termed 1t, which had the lowest IC(50) values, was assessed in a murine malarial model. Nuclear magnetic resonance imaging and Balb/c mice infected with Plasmodium berghei ANKA strain were treated in a 4-day suppressive test. Mice received a once-daily intraperitoneal administration of 50 mg/Kg of the drug for 4 days. Although no parasitaemia clearance was reached, a slower parasite proliferation and a slightly longer survival time compared with the placebo group were observed.

A PDA-based system for online recording and analysis of concurrent events in complex behavioral processes

This article outlines how a Palm- or Newton-based PDA (personal digital assistant) system for online event recording was used to record and analyze concurrent events. We describe the features of this PDA-based system, called the FIT-System (flexible interface technique), and its application to the analysis of concurrent events in complex behavioral processes--in this case, anesthesia work processes. The patented FIT-System has a unique user interface design allowing the user to design an interface template with a pencil and paper or using a transparency film. The template usually consists of a drawing or sketch that includes icons or symbols that depict the observer's representation of the situation to be observed. In this study, the FIT-System allowed us to create a design for fast, intuitive online recording of concurrent events using a set of 41 observation codes. An analysis of concurrent events leads to a description of action density, and our results revealed a characteristic distribution of action density during the administration of anesthesia in the operating room. This distribution indicated the central role of the overlapping operations in the action sequences of medical professionals as they deal with the varying requirements of this complex task. We believe that the FIT-System for online recording of concurrent events in complex behavioral processes has the potential to be useful across a broad spectrum of research areas.

Specific inhibition of transcription factor NF-kappaB through intracellular protein delivery of I kappaBalpha by the Herpes virus protein VP22

In many cancers, a high constitutive activation of transcription factor NF-kappaB has been implicated in tumor progression and apoptosis resistance, making NF-kappaB an attractive target for cancer therapy. Here, we describe the specific inhibition of NF-kappaB by the intracellular delivery of IkappaBalpha through VP22-mediated protein transduction. The Herpes virus protein VP22 has attracted great attention in gene therapy, because of its ability to migrate from an original expressing cell into surrounding recipient cells, resulting in high levels of protein transduction. To evaluate the use of VP22 as a vehicle for NF-kappaB inhibition, we expressed several versions of VP22-IkappaBalpha fusion proteins in baculovirus, bacteria, and mammalian cells. While we could not detect transcellular migration of different VP22-IkappaBalpha constructs, interestingly, baculovirally expressed VP22-IkappaBalpha was efficiently delivered into cells after exogenous administration. The purified and imported VP22-IkappaBalpha retained its function and efficiently inhibited both constitutive and inducible NF-kappaB activation. We further show that the 34 C-terminal amino acids of VP22 were sufficient for the import property, suggesting also that the ability of intercellular migration and cellular import are not linked to each other. Together, our results demonstrate that recombinant VP22 acts as an efficient vehicle for the exogenous delivery of IkappaBalpha and, moreover, might find applications to block NF-kappaB activation specifically.

[Participation--oriented analysis of the anesthesia workplace. A work system for anesthesia in a multidisciplinary operating room]

INTRODUCTION

The aim of this study was the detection and understanding of weak points in the ergonomic design of anaesthesia workplaces in a multidisciplinary operating room facility.

METHODS

Analysis of workplaces and of working processes by means of observations, computer-supported task recording and video-photo documentation. During guided interviews the participants were provided with material for naming-by-pointing and drawing. Subsequently, the background of the problems encountered and possible improvements were visualised.

RESULTS

Important deficits were devices not positioned within reach and view, difficulties in operating the lines connecting the patient and the devices, and inconsistent workplace layouts. These were caused by erroneous planning of the facility and disregarding ergonomic principles in equipment design. The initial improvements implemented were the development of a new concept for a flexible equipment positioning and the design of a tool for cable handling.

DISCUSSION AND CONCLUSION

Although from the very beginning of the study the anaesthesia personnel quoted the handling of the lines connecting patients and devices as the main cause for working difficulties, the external ergonomist could contribute to a broader view of the problems. The method presented here initiated a mutual learning process between ergonomist and users and resulted in a common understanding of the problems and their causes. Compared to the traditional consulting process, more time and efforts were necessary but were offset by the users' acceptance of the improvements and the prevention of design errors.

Caspase activation correlates with the degree of inflammatory liver injury in chronic hepatitis C virus infection

Hepatitis C virus (HCV) infection is a major cause of liver disease characterized by inflammation, cell damage, and fibrotic reactions of hepatocytes. Apoptosis has been implicated in the pathogenesis, although it is unclear whether proteases of the caspase family as the central executioners of apoptosis are involved and how caspase activation contributes to liver injury. In the present study, we measured the activation of effector caspases in liver biopsy specimens of patients with chronic HCV infection. The activation of caspase-3, caspase-7, and cleavage of poly(ADP-ribose)polymerase (PARP), a specific caspase substrate, were measured by immunohistochemistry and Western blot analysis by using antibodies that selectively detect the active truncated, but not the inactive precursor forms of the caspases and PARP. We found that caspase activation was considerably elevated in liver lobules of HCV patients in comparison to normal controls. Interestingly, the immunoreactive cells did yet not reveal an overt apoptotic morphology. The extent of caspase activation correlated significantly with the disease grade, i.e., necroinflammatory activity. In contrast, no correlation was observed with other surrogate markers such as serum transaminases and viral load. In biopsy specimens with low activity (grade 0) 7.7% of the hepatocytes revealed caspase-3 activation, whereas 20.9% of the cells stained positively in grade 3. Thus, our results suggest that caspase activation is involved in HCV-associated liver injury. Moreover, measurement of caspase activity may represent a reliable marker for the early detection of liver damage, which may open up new diagnostic and therapeutic strategies in HCV infection.

Potential and caveats of TRAIL in cancer therapy

Induction of apoptosis in tumor cells is a major goal for chemotherapy and radiation treatment strategies. However, disordered gene expression often leads to apoptosis resistance rendering tumor cells insensitive to various conventional treatments. TNF-related apoptosis-inducing ligand (TRAIL) is a recently identified cytokine of the TNF superfamily that induces apoptosis in tumor cells upon binding to different receptors. Remarkably, the majority of tumor cell lines are sensitive to TRAIL-induced apoptosis, while most nontransformed cell types are TRAIL-resistant. Furthermore, a combination treatment of TRAIL with ionizing irradiation or chemotherapeutic agents induces apoptosis in a highly synergistic manner, particularly in those cells that are otherwise resistant to a sole treatment. In contrast to other TNF members, TRAIL apparently does not exert overt systemic toxicity in murine and primate models, although unexpected concerns about a potential hepatotoxicity of TRAIL have been recently raised. While the molecular mechanisms of TRAIL sensitivity and resistance are poorly understood, TRAIL seems to be a promising biological agent for combination therapy with chemotherapeutic drugs or irradiation.

Characterization of catalytic centre mutants of macrophage migration inhibitory factor (MIF) and comparison to Cys81Ser MIF

Macrophage migration inhibitory factor (MIF) displays both cytokine and enzyme activities, but its molecular mode of action is still unclear. MIF contains three cysteine residues and we showed recently that the conserved Cys57-Ala-Leu-Cys60 (CALC) motif is critical for the oxidoreductase and macrophage-activating activities of MIF. Here we probed further the role of this catalytic centre by expression, purification, and characterization of the cysteine-->serine mutants Cys60Ser, Cys57Ser/Cys60Ser, and Cys81Ser of human MIF and of mutants Ala58Gly/Leu59Pro and Ala58Gly/Leu59His, containing a thioredoxin (Trx)-like and protein disulphide isomerase (PDI)-like dipeptide, respectively. The catalytic centre mutants formed inclusion bodies and the resultant mutant proteins Cys57Ser/Cys60Ser, Ala58Gly/Leu59Pro, and Als58Gly/Leu59His were only soluble in organic solvent or 6 m GdmHCl when reconstituted at concentrations above 1 microgram.mL-1. This made it necessary to devise new purification methods. By contrast, mutant Cys81Ser was soluble. Effects of pH, solvent, and ionic strength conditions on the conformation of the mutants were analysed by far-UV CD spectropolarimetry and mutant stability was examined by denaturant-induced unfolding. The mutants, except for mutant Cys81Ser, showed a close conformational similarity to wild-type (wt) MIF, and stabilization of the mutants was due mainly to acid pH conditions. Intramolecular disulphide bond formation at the CALC region was confirmed by near-UV CD of mutant Cys60Ser. Mutant Cys81Ser was not involved in disulphide bond formation, yet had decreased stability. Analysis in the oxidoreductase and a MIF-specific cytokine assay revealed that only substitution of the active site residues led to inactivation of MIF. Mutant Cys60Ser had no enzyme and markedly reduced cytokine activity, whereas mutant Cys81Ser was active in both tests. The Trx-like variant showed significant enzyme activity but was less active than wtMIF; PDI-like MIF was enzymatically inactive. However, both variants had full cytokine activity. Together with the low but nonzero cytokine activity of mutant Cys60Ser, this indicated that the cytokine activity of MIF may not be tightly regulated by redox effects or that a distinguishable receptor mechanism exists. This study provides evidence for a role of the CALC motif in the oxidoreductase and cytokine activities of MIF, and suggests that Cys81 could mediate conformational effects. Availability and characterization of the mutants should greatly aid in the further elucidation of the mechanism of action of the unusual cytokine MIF.