The Role of Coronary Artery Calcium Score to Assess Risk of Cardiovascular Disease in Irradiated Esophageal Cancer Patients

PURPOSE/OBJECTIVE(S)

Coronary artery calcium (CAC) score is an important predictive imaging marker of cardiovascular disease (CVD). While studies have found positive association between CAC score and cardiac toxicity in irradiated lung and breast cancer patients, there are no studies assessing CAC scores in esophageal cancer (EC). While a cardiac-gated CT is required for standard Agatston CAC score, visual assessment of CAC via ordinal scoring on non-gated CT has shown good concordance with Agatston score. In this study, we sought to examine whether visual assessment of CAC, measured on standard of care, non-contrast chest CT, predicts the development of adverse cardiovascular events (ACVE) in irradiated EC patients.

MATERIALS/METHODS

This is a single institution retrospective study of EC patients treated with RT from 2010-2021. We included patients with available PET/CT at diagnosis or chest CT simulation scan without contrast, and excluded those with history of percutaneous coronary intervention, coronary bypass surgery, or prior thoracic RT. Pre-treatment characteristics, clinical factors, and grade ≥ 3 (G3+) adverse cardiovascular events (ACVE) (CTCAEv5.0) were evaluated. Visual assessment of CAC was performed using ordinal method (CAC scored from 0 to 12), by a thoracic radiologist. Fine and Gray regression was used to compute hazard ratios for time to first ACVE. Univariate analyses using Cox proportional hazards were used for overall survival (OS). ACVEs were recorded from start of oncologic treatment and OS calculated after completion of RT.

RESULTS

A total of 118 patients were analyzed with a median follow-up of 16 months. Median age was 67 years, 65% male, 43% white, 59% with EC of distal esophagus, and 59% had squamous cell carcinoma. Median mean heart dose was 21.93 Gy (range 0.15-36.94). 24% developed G3+ ACVEs: atrial fibrillation 9%, stroke 6%, heart failure 4%, pulmonary embolism 4%, pericardial effusion 3%, myocardial infarction 2%, heart block 2%, and cardiac death 1%. On univariate analyses, CAC >1 vs. CAC ≤ 1 trended towards increased risk of ACVE (HR = 1.95, 95% CI = 0.89-4.26; p = 0.094), however it is not predictive of OS (HR = 1.31, 95% CI = 0.75-2.30; p = 0.343). Proportion of patients with ACVEs was greater in CAC>1 group (Table). When compared to patients with CAC ≤ 1, those with CAC >1 were older (median age 62 vs 72 years, p = 0.0015), less likely to be never smokers (38% vs 30%, p = 0.0437), and more likely to have hypertension (43% vs 64%, p = 0.0197), and hyperlipidemia (30% vs 47%, p = 0.0557).

CONCLUSION

This is the first study to investigate the relationship between CAC score and ACVEs in EC. While the study was underpowered (likely due to low rates of recorded ACVEs), to detect a significant association between CAC score and ACVEs, there was a trend towards increased risk of ACVEs in patients with a CAC score >1 by visual ordinal scoring. Further prospective evaluation with a larger cohort is warranted.

Tumor Apolipoprotein E is a key checkpoint blocking anti-tumor immunity in mouse melanoma

Immunotherapy is a key modality in the treatment of cancer, but many tumors remain immune resistant. The classic mouse model of B16-F10 melanoma is immune resistant even in the face of checkpoint inhibition. Apolipoprotein E (apoE), a known immune suppressant is strikingly elevated in many human tumors, but its role in cancer immunology is not defined. We investigated the role of apoE in the immune micro-environment using a mouse melanoma model. We demonstrate that ApoE is -highly expressed in wild-type B16-F10 melanoma and serum levels progressively increase as tumors grow. The conditioned media from wild type ApoE secreting melanoma cells suppress T-cell activation in vitro while this suppressive effect is absent in conditioned media from ApoE knock out tumor cells. Mechanistically, apoE induces IL-10 secreting dendritic cells and stimulates T-cell apoptosis and arrest partially via the lrp8 receptor. Ablating ApoE in mice inoculated with tumor cells enabled tumor cell rejection and was associated with induction of immune pathway activation and immune cell infiltration. Tumor secreted apoE appears to be a potent immune cell checkpoint and targeting apoE is associated with enhanced tumor immunity in the mouse melanoma model.

Cancer-associated fibroblasts of the prostate promote a compliant and more invasive phenotype in benign prostate epithelial cells

Reciprocal interactions between prostate epithelial cells and their adjacent stromal microenvironment not only are essential for tissue homeostasis but also play a key role in tumor development and progression. Malignant transformation is associated with the formation of a reactive stroma where cancer-associated fibroblasts (CAFs) induce matrix remodeling and thereby provide atypical biochemical and biomechanical signals to epithelial cells. Previous work has been focused on the cellular and molecular phenotype as well as on matrix stiffness and remodeling, providing potential targets for cancer therapeutics. So far, biomechanical changes in CAFs and adjacent epithelial cells of the prostate have not been explored. Here, we compared the mechanical properties of primary prostatic CAFs and patient-matched non-malignant prostate tissue fibroblasts (NPFs) using atomic force microscopy (AFM) and real-time deformability cytometry (RT-FDC). It was found that CAFs exhibit an increased apparent Young's modulus, coinciding with an altered architecture of the cytoskeleton compared with NPFs. In contrast, co-cultures of benign prostate epithelial (BPH-1) cells with CAFs resulted in a decreased stiffness of the epithelial cells, as well as an elongated morphological phenotype, when compared with co-cultures with NPFs. Moreover, the presence of CAFs increased proliferation and invasion of epithelial cells, features typically associated with tumor progression. Altogether, this study provides novel insights into the mechanical interactions between epithelial cells with the malignant prostate microenvironment, which could potentially be explored for new diagnostic approaches.

Standardized microgel beads as elastic cell mechanical probes

Cell mechanical measurements are gaining increasing interest in biological and biomedical studies. However, there are no standardized calibration particles available that permit the cross-comparison of different measurement techniques operating at different stresses and time-scales. Here we present the rational design, production, and comprehensive characterization of poly-acrylamide (PAAm) microgel beads mimicking size and overall mechanics of biological cells. We produced mono-disperse beads at rates of 20-60 kHz by means of a microfluidic droplet generator, where the pre-gel composition was adjusted to tune the beads' elasticity in the range of cell and tissue relevant mechanical properties. We verified bead homogeneity by optical diffraction tomography and Brillouin microscopy. Consistent elastic behavior of microgel beads at different shear rates was confirmed by AFM-enabled nanoindentation and real-time deformability cytometry (RT-DC). The remaining inherent variability in elastic modulus was rationalized using polymer theory and effectively reduced by sorting based on forward-scattering using conventional flow cytometry. Our results show that PAAm microgel beads can be standardized as mechanical probes, to serve not only for validation and calibration of cell mechanical measurements, but also as cell-scale stress sensors.

The genetic basis for most patients with pustular skin disease remains elusive

BACKGROUND

Rare variants in the genes IL36RN, CARD14 and AP1S3 have been identified to cause or contribute to pustular skin diseases, primarily generalized pustular psoriasis (GPP).

OBJECTIVES

To better understand the disease relevance of these genes, we screened our cohorts of patients with pustular skin diseases [primarily GPP and palmoplantar pustular psoriasis (PPP)] for coding changes in these three genes. Carriers of single heterozygous IL36RN mutations were screened for a second mutation in IL36RN.

METHODS

Coding exons of IL36RN, CARD14 and AP1S3 were sequenced in 67 patients - 61 with GPP, two with acute generalized exanthematous pustulosis and four with acrodermatitis continua of Hallopeau. We screened IL36RN and AP1S3 for intragenic copy-number variants and 258 patients with PPP for coding changes in AP1S3. Eleven heterozygous IL36RN mutations carriers were analysed for a second noncoding IL36RN mutation. Genotype-phenotype correlations in carriers/noncarriers of IL36RN mutations were assessed within the GPP cohort.

RESULTS

The majority of patients (GPP, 64%) did not carry rare variants in any of the three genes. Biallelic and monoallelic IL36RN mutations were identified in 15 and five patients with GPP, respectively. Noncoding rare IL36RN variants were not identified in heterozygous carriers. The only significant genotype-phenotype correlation observed for IL36RN mutation carriers was early age at disease onset. Additional rare CARD14 or AP1S3 variants were identified in 15% of IL36RN mutation carriers.

CONCLUSIONS

The identification of IL36RN mutation carriers harbouring additional rare variants in CARD14 or AP1S3 indicates a more complex mode of inheritance of pustular psoriasis. Our results suggest that, in heterozygous IL36RN mutation carriers, there are additional disease-causing genetic factors outside IL36RN.

Real-time deformability cytometry as a label-free indicator of cell function

The mechanical properties of cells are known to be a label-free, inherent marker of biological function in health and disease. Wide-spread utilization has so far been impeded by the lack of a convenient measurement technique with sufficient throughput. To address this unmet need, we have recently introduced real-time deformability cytometry (RT-DC) for continuous mechanical single-cell classification of heterogeneous cell populations at rates of several hundred cells per second. Cells are driven through the constriction zone of a microfluidic chip leading to cell deformations due to hydrodynamic stresses only. Our custom-built image processing software performs image acquisition, image analysis and data storage on the fly. The ensuing deformations can be quantified and an analytical model enables the derivation of cell material properties. Performing RT-DC we highlight its potential to identify rare objects in heterogeneous suspensions and to track drug-induced changes in cells. In summary, RT-DC enables marker-free, quantitative phenotyping of heterogeneous cell populations with a throughput comparable to standard flow cytometry.

Prevalence and comorbidities in adults with psoriasis compared to atopic eczema

BACKGROUND

Most data suggesting an association between psoriasis and cardiovascular disease (CVD) have come from specialized populations at either low or high risk of CVD. Atopic dermatitis (AD) has been associated with a number of modifiable risk factors, particularly obesity. There has been a recent controversy on the suggestion that associations with comorbidities in psoriasis may be due to overreporting or biased by disease severity and therefore not necessarily representative of the general psoriasis population.

OBJECTIVES

To evaluate the prevalence of AD and psoriasis and to compare the prevalence rates of comorbidities based on a large sample of health insurance data.

METHODS

Data were collected from a database of non-selected individuals from a German statutory health insurance organization that covers all geographic regions. Individuals identified by International Classification of Diseases (ICD)-10 codes applied to all outpatient and inpatient visits in the year 2009. Comorbidities were evaluated by ICD-10 diagnoses.

RESULTS

The database consisted of 1 642 852 members of a German statutory health insurance. Of 1 349 671 data sets analyzed, 37 456 patients ≥18 years were diagnosed with psoriasis (prevalence 2.78%), and 48 140 patients ≥18 years of age were diagnosed with AD, equivalent to a prevalence of 3.67%. Patients with psoriasis showed increased rates of comorbidities in all age groups. Comorbidities related to the metabolic syndrome including arterial hypertension [prevalence ratio (PR), 1.94; 95% confidence interval (CI), 1.90-1.98], hyperlipidaemia (PR, 1.77; 95% CI, 1.73-1.81), obesity (PR, 1.74; 95% CI, 1.69-1.79) and diabetes mellitus (PR, 1.88; 95% CI, 1.83-1.94) were significantly more common among patients with psoriasis compared to AD.

CONCLUSIONS

Diseases forming part of the metabolic syndrome showed significant lower prevalence rates in patients with AD than in patients with psoriasis. Within the limitations of secondary healthcare data, our study disproves the suggestion that associations with comorbidities in psoriasis may be biased by a higher degree of severity or overreporting.

Farm Exposure as a Differential Risk Factor in ANCA-Associated Vasculitis

Objective

To investigate the association of farm exposure and the development of ANCA-associated vasculitis (AAV).

Methods

One hundred eighty-nine well defined patients with AAV (n = 119 with granulomatosis with polyangiitis [GPA], n = 48 with microscopic polyangiitis [MPA], n = 22 patients with eosinophilic granulomatosis with polyangiitis [EGPA]) and 190 controls (n = 119 patients with rheumatoid arthritis, n = 71 with large vessel vasculitis) were interrogated using a structured questionnaire. Factors investigated were occupation, farm exposure, contact to different livestock, participation in harvesting, residence next to a farm, MRSA status, and contact to domestic pets at disease onset or ever before. The odds ratio (OR) and 95% confidence interval [95%CI] were calculated for each item.

Results

Univariate analysis revealed a strong association of AAV with regular farm exposure; OR 3.44 [95%CI 1.43–8.27]. AAV was also associated with regular contact to cattle 4.30 (1.43–8.27), pigs 2.75 (1.12–6.75) and MRSA carriage 3.38 (1.11–10.3). This association was stronger in the subgroup of GPA patients. OR in this group for farm exposure was 4.97; [2.02–12.2], for cattle 6.71 [95% CI 2.19–20.7], for pigs 4.34 [1.75–10.9], and MRSA carriage 5.06 [1.62–15.8]). There was no significant association of MPA or EGPA with these parameters.

Conclusion

A significant association between farm exposure or farm animal exposure and AAV especially in the subgroup of patients with GPA has been identified. This suggests that these entities are distinct and have different triggers for the immune process.

Nail involvement as a predictor of concomitant psoriatic arthritis in patients with psoriasis

BACKGROUND

Patients with psoriatic arthritis (PsA) suffer from increased burden of disease and impairments in quality of life. Early detection and treatment of PsA could contribute to the prevention of clinical and radiological progression.

OBJECTIVES

To analyse the predictive value of clinical and patient-reported outcomes for concomitant PsA in a population-based cohort of patients with psoriasis.

METHODS

We performed a retrospective analysis of data from three independent national cross-sectional studies on health care in psoriasis and PsA, conducted in Germany in the years 2005, 2007 and 2008. Patients with psoriasis were included in the study by dermatologists (n = 3520) and via the German patient advocacy group for psoriasis (n = 2449). In all studies, psoriasis history, clinical findings, PsA, nail involvement, health care and patient-reported outcomes were collected with standardized questionnaires.

RESULTS

In the regression model on 4146 patients the strongest predictors for concomitant PsA were nail involvement [odds ratio (OR) 2·93, 95% confidence interval (CI) 2·51-3·42, P < 0·001] and inpatient hospital treatment (OR 1·63, 95% CI 1·38-1·93, P < 0·001). By contrast, scalp involvement was not a significant predictor.

CONCLUSIONS

Patients with psoriasis seen by dermatologists and those in patient advocacy groups show clinical indicators of PsA, the most predictive being nail disease. In practice, a comprehensive assessment of clinical findings associated with PsA is needed.

The 2009 influenza A (H1N1) pandemic. Management and vaccination strategies in The Netherlands

Prior to 2009, The Netherlands had prepared itself extensively for a potential pandemic. Multidisciplinary guidelines had been drafted to control transmission and limit adverse outcomes for both a phase of early incidental introduction and for a phase with widespread transmission. The Ministry of Health had ensured a supply and distribution schedule for antivirals and negotiated a contract for vaccine purchases. During the pandemic, existing surveillance was expanded, the established infectious disease response structure was activated, and the previously prepared protocols for communication, diagnostics, use of antivirals, and vaccination implementation were operationalized and implemented.

When the pandemic turned out to be less severe than many had anticipated, risk communication and rapid modification of guidelines and communication became a major challenge. Antivirals and pandemic vaccines were reserved for those at high risk for severe outcomes only. Overall, the impact of the pandemic was comparable to the impact of an average seasonal influenza epidemic, but with a shift in (severe) outcomes from the very young and elderly toward young adults. Established prepared protocols enabled timely coordinated responses. In preparing for the worst, sufficient attention must be given to preparing for a mild scenario as well.

Repetitive transcranial magnetic stimulation influences mood in healthy male volunteers

Introduction

The influence of repetitive transcranial magnetic stimulation (rTMS) on mood in healthy people is uncertain, as former studies show divergent results. Previous studies in healthy volunteers focused exclusively on the immediate effect of a single session of rTMS on mood.

Aims

The aim of this study was to analyse the influence on mood of a series of 9 High Frequency (HF) rTMS stimulations of the left dorsolateral prefrontal cortex (DLPFC).

Methods

44 young healthy male volunteers were randomly assigned to receive 9 sessions of active HF-rTMS (n = 22) or sham rTMS (n = 22) over the left DLPFC. Each session in the active group consisted of 15 trains of 25 Hz starting with 100% of motor threshold. Sham stimulation was performed following the same protocol, but using a sham coil. The variables of interest were the Beck Depression Inventory (BDI) and Visual Analogue Scales (VAS) which quantified “mood”, “enjoyment” and “energy”.

Results

We found a significant reduction of the BDI score in the active group (GLM, p < 0.001) whereas no significant changes of the BDI score were caused by sham stimulation (GLM, p = 0.109). We did not find significant differences caused by active or sham stimulation in VAS scales except for the VAS labelled lively/gloomy immediately after stimulation. The active group was found to be more “gloomy” (p = 0.001).

Conclusions

Our data support the hypothesis that a 9-day long series of HF-rTMS of the left DLPFC improves mood, analysed by BDI in healthy young men.

Expression pattern differences between osteoarthritic chondrocytes and mesenchymal stem cells during chondrogenic differentiation

OBJECTIVE

The use of mesenchymal stem cells (MSCs) for cartilage regeneration is hampered by lack of knowledge about the underlying molecular differences between chondrogenically stimulated chondrocytes and MSCs. The aim of this study was to evaluate differences in phenotype and gene expression between primary human chondrocytes and MSCs during chondrogenic differentiation in three-dimensional (3D) pellet culture (PC).

MATERIALS AND METHODS

Chondrocytes isolated from cartilage samples obtained during total knee alloarthroplastic procedure (N=8) and MSCs, purified from bone marrow aspirates of healthy donors (N=8), were cultivated in PC under chondrogenic conditions. Immunohistology and quantitative reverse transcribing PCR (RT-PCR) were performed for chondrogenic-specific markers (i.e., Sox9, Collagen II). Global gene expression of the so-cultivated chondrocytes and MSCs was assessed by a novel approach of microarray-based pathway analysis. Refinement of data was done by hypothesis-driven gene expression omnibus (GEO) dataset comparison. Validation was performed with separate samples in transforming growth factor (TGF)β+ or TGFβ- conditions by use of quantitative real-time RT-PCR.

RESULTS/CONCLUSIONS

Chondrogenic commitment of both cell types was observed. Interestingly, chondrocytes demonstrated an upregulated fatty acid/cholesterol metabolism which may give hints for future optimization of culture conditions. The novel microarray-based pathway analysis applied in this study seems suitable for the evaluation of whole-genome based array datasets in case when hypotheses can be backed with already existing GEO datasets. Future experiments should further explore the different metabolic behaviour of chondrocytes and MSC.

[Systemic lupus erythematosus. Target criteria for treatment]

Systemic lupus erythematosus (SLE) is a chronic systemic intermittent autoimmune disease, which can affect nearly all organ systems. The disease is characterized by the detection of more than 100 different auto-antibodies. For the clinical practice as well as in controlled clinical studies it is absolutely necessary to define target criteria which allow the evaluation of the effectiveness of therapy. Many instruments are available for measuring the activity of the disease, the quality of life, the extent of irreversible damage and the individual manifestation in organs. There are also now various biomarkers to characterize the pathophysiologic aspects, clinical activity, therapeutic effectiveness and prognosis.

Treatment of inflammatory dermatoses by tumour necrosis factor antagonists

BACKGROUND

The treatment of inflammatory skin diseases is at present often empirical as causal therapeutic approaches, based on an incomplete knowledge of the immune pathogenesis, are mostly unavailable. The currently applied treatments can in fact lead to remission of the disease; however, under certain circumstances undesirable side-effects must be expected. On the basis of experience gained in cytokine modulation therapy of chronic inflammatory diseases such as rheumatoid arthritis and psoriasis, the application of TNF-alpha inhibitors represents a novel, more specific, and effective therapeutic option for distinct chronic inflammatory diseases.

PATIENTS AND METHODS

The current status of the therapeutic effect of TNF-alpha blockers is discussed based on our own observations and a review of the current literature. Also discussed are potential undesirable side-effects and possible contraindications of this therapy.

RESULTS AND CONCLUSIONS

Based on recent findings, the use of TNF-alpha blockers seems to be promising in the treatment of therapy-resistant inflammatory dermatoses. At present, guidelines for indications and contraindications of anti-TNF-alpha treatment of inflammatory skin disorders are rare. Such guidelines are necessary to improve the efficacy of anticytokine treatment and the reduction of side-effects.

Comparison of immunoglobulin heavy chain rearrangements between peripheral and glandular B cells in a patient with primary Sjögren's syndrome

Myoepithelial sialadenitis (MESA) of the major salivary glands is a characteristic feature of primary Sjögren's syndrome (pSS). To delineate systemic and organ-specific influences on B cells in a patient with pSS and benign MESA, individual B cells were simultaneously obtained from the peripheral blood and inflamed parotid gland. Immunoglobulin variable heavy chain (VH) rearrangements in single sorted CD19+ B cells were subsequently amplified, sequenced and analysed. Despite the presence of two clonal expansions using VH1-08 and VH2-70 segments, respectively, the majority of glandular B cells were polyclonal, resembling the VH gene usage and mutational pattern of the corresponding blood population. However, striking differences were observed in the proportion of cells expressing mutated VH rearrangements (blood, 28.9% versus parotid, 80.4%; P < 0.0001). Moreover, the glandular productive VH rearrangements differed significantly from their blood counterparts by a higher mutational frequency (P < 0.0001), shorter CDR3 lengths (P = 0.001) and a less frequent usage of JH6 (P = 0.0292), indicating an accumulation of memory B cells in the inflamed parotid. Thus, both preferential influx/homing of memory B cells and local proliferation may contribute to the pattern of benign MESA in pSS. Notably, one of the glandular clonal rearrangements (using VH1-08) was also detected in the patient's peripheral repertoire.

Immunoglobulin Vlambda light chain gene usage in patients with Sjögren's syndrome

OBJECTIVE

To determine whether patients with Sjögren's syndrome (SS) have abnormalities in Ig Vlambda and Jlambda gene usage, differences in somatic hypermutation, defects in selection, or indications for perturbations of B cell maturation.

METHODS

Individual peripheral B cells from SS patients were analyzed for their Vlambda gene usage by single-cell polymerase chain reaction amplification of genomic DNA and compared with those from normal controls.

RESULTS

Molecular differences from controls in Vlambda-Jlambda recombination were identified that were reflected by findings in the nonproductive Vlambda repertoire of the patients, including enhanced rearrangement of Vlambda10A and Jlambda2/3 gene segments. In addition, a number of abnormalities in the productive repertoire were identified, indicating disordered selection. A greater usage of 4 Vlambda genes (2A2, 2B2, 2C, and 7A), representing 56% of all productive Vlambda rearrangements, was observed, suggesting positive selection of these genes. Overutilization of Jlambda2/3 and underutilization of Jlambda7 in both nonproductive and productive Vlambda rearrangements of SS patients compared with controls suggested decreased receptor editing in SS. The mutational frequency did not differ from that in controls, and positive selection of mutations into the productive V gene repertoire was found, similar to that in controls, although mutational targeting toward RGYW/WRCY motifs, typically found in controls, was not found in SS patients.

CONCLUSION

Disturbed regulation of B cell maturation with abnormal selection, defects in editing Ig receptors, and abnormal mutational targeting may contribute to the emergence of autoimmunity in SS.

Immunoglobulin Vkappa light chain gene analysis in patients with Sjögren's syndrome

OBJECTIVE

Patients with Sjögren's syndrome (SS) have characteristic lymphocytic infiltration of the salivary glands with a previously reported predominance of Vkappa-bearing B cells and produce a variety of autoantibodies, indicating that there is a humoral autoimmune component in this syndrome. This study was undertaken to determine whether there are primary deviations of immunoglobulin V gene usage, differences in somatic hypermutation, defects of selection, or indications for perturbances of B cell maturation in SS.

METHODS

Individual peripheral B cells from patients with SS were analyzed for their Ig V gene usage, and the findings were compared with results in normal controls.

RESULTS

Molecular differences, as reflected by findings in the nonproductive Vkappa repertoire of the patients, were identified by an enhanced usage of Jkappa2 gene segments and a lack of mutational targeting toward RGYW/WRCY sequences compared with controls. A greater usage of Vkappa1 family members and a reduced frequency of Vkappa3 gene segments in the productive repertoire suggested differences in selection, possibly driven by antigen. Overall positive selection for mutations, especially for replacements in the complementarity-determining region and for mutations in RGYW/WRCY, similar to that found in controls, was detected.

CONCLUSION

Disturbances of strictly regulated B cell maturation, during early B cell development as indicated by prominent Jkappa2 gene usage and during germinal center reactions as indicated by a lack of targeting of the hypermutation mechanism, might contribute to the emergence of autoimmunity in SS.

Disturbed peripheral B lymphocyte homeostasis in systemic lupus erythematosus

In patients with active systemic lupus erythematosus (SLE), a marked B lymphocytopenia was identified that affected CD19(+)/CD27(-) naive B cells more than CD19(+)/CD27(+) memory B cells, leading to a relative predominance of CD27-expressing peripheral B cells. CD27(high)/CD38(+)/CD19(dim)/surface Ig(low)/CD20(-)/CD138(+) plasma cells were found at high frequencies in active but not inactive SLE patients. Upon immunosuppressive therapy, CD27(high) plasma cells and naive CD27(-) B cells were markedly decreased in the peripheral blood. Mutational analysis of V gene rearrangements of individual B cells confirmed that CD27(+) B cells coexpressing IgD were memory B cells preferentially using V(H)3 family members with multiple somatic mutations. CD27(high) plasma cells showed a similar degree of somatic hypermutation, but preferentially employed V(H)4 family members. These results indicate that there are profound abnormalities in the various B cell compartments in SLE that respond differently to immunosuppressive therapy.

Preparation and oxygenation of (flavonolato)copper isoindoline complexes with relevance to quercetin dioxygenase

Mesitylcopper reacts with flavonol (flaH) in the presence of 1,3-bis(2-pyridylimino)isoindoline (indH) to yield the diamagnetic complex CuI(fla)(indH), which on reaction with molecular oxygen undergoes oxidative splitting of the C2-C3 bond of the pyranone ring of the flavonolate ligand to give CuI(indH)(O-bs) (O-bs = O-benzoylsalicylate) (orthorhombic, P1, a = 8.048(7) A, b = 8.969(9) A, c = 19.240(2) A, alpha = 85.69 degrees, beta = 80.24(7) degrees, gamma = 77.87(7) degrees, V = 1337(2) A3, Z = 2) and carbon monoxide. The reaction of [CuI(CH3CN)4]ClO4, flaH, and indH with dioxygen at room temperature affords the paramagnetic complex [CuII(fla)(indH)]ClO4 (mu = 2.10 mu B), and after elimination of HClO4, CuII(fla)(ind) (orthorhombic, Pbca, a = 8.888(2) A, b = 19.169(7) A, c = 33.614(10) A, alpha = beta = gamma = 90 degrees, V = 5727(3) A3, Z = 8) with mu = 1.86 mu B is formed. The latter undergoes cleavage of the pyranone ring on oxygenation at 80 degrees C to give CuII(ind)(O-bs) (mu = 1.87 mu B, nu(CO) = 1742 cm-1, and nu(CO2) = 1581, 1387 cm-1) and carbon monoxide. CuII(fla)(ind) and [CuII(fla)(indH)]ClO4 serve as good catalysts for the oxygenation of flavonol to O-benzoylsalicyclic acid.

Determination of eicosanoid and cytokine production in salvaged blood, stored red blood cell concentrates, and whole blood

STUDY OBJECTIVE

To determine the production of the eicosanoids prostaglandin 2 (PGE2) and thromboxane 2 (TxB2) and the cytokines interleukin 1 beta (IL-1-beta) and interleukin 6 (IL-6) in whole blood (WB), unfiltered red blood cell (RBC), and filtered RBC concentrates, and salvaged blood.

DESIGN

Prospective study.

SETTING

University hospital of Erlangen.

PATIENTS

32 healthy volunteers and 14 ASA physical status I, II, and III radical prostatectomy patients (mean age 65 yrs).

INTERVENTIONS

Sixteen WB units and 16 RBC units (divided into 16 filtered and unfiltered units each) were taken from 32 volunteers. Fourteen salvaged RBC units were obtained from the 14 radical prostatectomy patients. Sixteen WB units were stored for 35 days. From the 16 WB donations, RBC concentrates (PAGGS-M) were prepared. The RBC concentrates were halved, one half had its leukocytes removed at day 0; both halves were stored for 49 days. Salvaged blood (n = 14) was stored up to 2 hours during surgery and then retransfused.

MEASUREMENTS AND MAIN RESULTS

Immediately at the start of the study, in all blood units (WB, RBC filtered, and RBC unfiltered units) at days 0 and 21, and at the end of the storage period (WB: 35 days, RBC concentrates: 49 days) and in the salvaged RBC units, the following parameters were measured: PGE2, TxB2, IL-1-beta, IL-6, hematocrit, platelet number, leukocytes, blood volume, and hemoglobin. During storage, different levels of PGE2, TxB2, IL-1-beta, IL-6 for WB, filtered RBC concentrates, and unfiltered RBCs were found. The higher levels of PGE2, TxB2, IL-1-beta, and IL-6 were found in the WB and RBC salvaged units than the filtered RBCs or unfiltered RBC units. There was no statistically significant difference between WB and salvaged RBCs. Higher levels of leukocytes and platelets were found in WB units and salvaged RBCs as compared to filtered or unfiltered RBCs.

CONCLUSIONS

The eicosanoid and cytokine levels in the salvaged, filtered RBC, unfiltered RBC, and WB units stayed within physiological limits, suggesting that these levels do not contribute to the risk of nonhemolytic, immunomodulated transfusion reactions, even in massive transfusions.

Elimination of all charged residues in the vicinity of the active-site helix of the disulfide oxidoreductase DsbA. Influence of electrostatic interactions on stability and redox properties

Disulfide oxidoreductases are structurally related proteins that share the thioredoxin fold and a catalytic disulfide bond that is located at the N terminus of an alpha-helix. The different redox potentials of these enzymes varying from -270 mV for thioredoxin to -125 mV for DsbA have been attributed to the lowered pKa values of their nucleophilic, active-site cysteines and the difference in thermodynamic stability between their oxidized and reduced forms (DeltaDeltaGox/red). The lowered pKa of the nucleophilic cysteine thiols was proposed to result from favorable interactions with the helix dipole and charged residues in their vicinity. In this study, we have eliminated all charged residues in the neighborhood of the active-site disulfide of DsbA from Escherichia coli to analyze their contribution to the physicochemical properties of the protein. We show that the conserved charge network among residues Glu24, Glu37, and Lys58 stabilizes the oxidized form of DsbA and thus does not cause the high redox potential of the enzyme. The pKa values of the nucleophilic cysteine (Cys30) and the redox potentials of the DsbA variants E24Q, E37Q, K58M, E24Q/K58M, E37Q/K58M, E24Q/E37Q, E24Q/E37Q/K58M, and E24Q/E37Q/E38Q/K58M are similar to those of DsbA wild type. The redox potentials of the variants neither correlate with the Cys30 pKa values nor with the DeltaDeltaGox/red values, demonstrating that the relationship between these parameters is far more complex than previously thought.

Replacement of Pro109 by His in TlpA, a thioredoxin-like protein from Bradyrhizobium japonicum, alters its redox properties but not its in vivo functions

TlpA, the membrane-anchored, thioredoxin-like protein from Bradyrhizobium japonicum, is essential for cytochrome aa3 biogenesis. The periplasmic domain of TlpA was previously shown to have protein thiol:disulfide oxidoreductase activity and reducing properties similar to those of cytoplasmic thioredoxins. Here, we replaced the proline-109 in its active-site sequence C107 V108 P109 C110 by a histidine residue. The resulting active-site motif (CVHC) resembles that of oxidizing thiol:disulfide oxidoreductases such as protein disulfide isomerase (PDI) and DsbA. Indeed, the TlpA variant P109H was by 66 mV more oxidizing than the wild-type protein. Nevertheless, the altered protein was even more efficient in catalyzing the reduction of insulin disulfides by dithiothreitol than the wild-type due to a faster recycling of its catalytically active, reduced form. Cells of B. japonicum expressing only the mutated tlpA gene had the same phenotypes as wild-type cells, suggesting that the change in the redox potential of TlpA was not critical for its in vivo function.

[Anti-inflammatory effects and aqueous humor concentration of various nonsteroidal anti-inflammatory drugs in extracapsular cataract surgery]

BACKGROUND

Within the spectrum of anti-inflammatory drugs, the preference of nonsteroidal anti-inflammatory drugs (NSAID) is definitely increasing. In the present study, we compared the anti-inflammatory effects and aqueous humour concentrations of 3 topical NSAID (indomethacin, diclofenac, and flurbiprofen) during extracapsular cataract surgery.

PATIENTS AND METHODS

We examined 90 patients (52-89 yrs of age) without pre-existing deficiencies of the blood-aqueous barrier. In 60 of these patients (series 1), and examination using the laser flare-cell meter was performed prior to and following extracapsular cataract surgery with intraocular lens implantation. In 30 patients (series 2), aqueous humour was drawn intraoperatively, and the NSAID concentration was determined using high-pressure liquid chromatography (HPLC). Patients were randomly assigned to one of the following three treatment protocols with commercially available NSAID: protocol A: indomethacin 1% eyedrops (Chibro-Amuno -3); protocol B: diclofenac 0.1% eyedrops (Voltaren ophtha); protocol C: flurbiprofen 0.03% eyedrops (Ocuflur). 2 drops of either drug were administered as follows: day before surgery (4:00 p.m., late night), day of surgery (2, 1, and 1/2 hrs preop, end of operation, 4:00 p.m., late night), and days 1-3 postoperatively (5 times per day).

RESULTS

Under indomethacin therapy (protocol A), the flare [in photon counts/ms] increased from a preoperative value of 8.0 +/- 2.8 (means +/- SE) to 20.1 +/- 2.2 on day 1 postoperatively, and decreased to 16.9 +/- 2.5 on day 3. Under diclofenac therapy (protocol 2), the flare averaged 25.8 +/- 3.8 and 16.9 +/- 2.8 on postoperative days 1 and 3, respectively. Under flurbiprofen therapy (protocol C), the flare amounted to 31.4 +/- 6.6 and 26.2 +/- 3.4 on days 1 and 3, respectively. On day 1 postoperatively, there was a significant difference (p < 0.01) between all three treatment protocols. Postoperative fibrin exsudation was observed in 1 of 20 indomethacin- and 1 of 20 flurbiprofen-treated patients (5%), and in 4 of 20 diclofenac-treated patients (20%). The highest individual aqueous humour concentration of indomethacin was 430 micrograms/1, the lowest 30. The concentrations of flurbiprofen lay between 42 and 31, those of diclofenac between 80 and 30 micrograms/1. All patients treated with indomethacin had detectable aqueous humour concentrations, whereas 3 flurbiprofen- and 7 diclofenac-treated patients had no HPLC-detectable concentrations (detection limit: 30 micrograms/1).

CONCLUSIONS

After extracapsular cataract surgery, the anti-inflammatory potency of topical indomethacin 1% is superior to that of flurbiprofen 0.03% and diclofenac 0.1%, as demonstrated by the laser flare-cell meter. The rate of postoperative fibrin exsudation is lower under treatment with topical indomethacin or flurbiprofen compared to diclofenac. Using the commercially available substances (with different drug concentrations and vehicles), indomethacin exhibits a higher aqueous humour concentration than flurbiprofen, and diclofenac shows the lowest concentration.

Genetical and RFLP studies at the Mla locus conferring powdery mildew resistance in barley

The complex structure of the multigene family at the Mla locus conferring powdery mildew resistance in barley was studied by making diallel crosses between several near-isogenic lines carrying different Mla alleles. The mode of inheritance of the Mla alleles investigated was determined to be dominant for Mla1, Mla6, Mla7 and Mla13 and semidominant for Mla3, Mla12 and Mla20. F1 plants were backcrossed to the susceptible recurrent parent in order to identify susceptible and double-resistant recombinants in the BC1F1 generation. Out of 17605 progenies tested in the BC1F1 generation, two susceptible recombinants, one between Mla1 and Mla12 and one between Mla13 and Mla20 were confirmed. The former was also verified by RFLP analysis.

The product of the hypB gene, which is required for nickel incorporation into hydrogenases, is a novel guanine nucleotide-binding protein

The products of the hyp operon genes are essential for the formation of catalytically active hydrogenases in Escherichia coli. At least one of these auxiliary proteins, HYPB, appears to be involved in nickel liganding to the hydrogenase apoprotein, since mutations in hypB can be phenotypically suppressed by high nickel concentrations in the medium (R. Waugh and D. H. Boxer, Biochimie 68:157-166, 1986). To approach the identification of the specific function of HYPB, we overexpressed the hypB gene and purified and characterized the gene product. HYPB is a homodimer of 31.6-kDa subunits, and it binds guanine nucleotides, with a Kd for GDP of 1.2 microM. The protein displays a low level of GTPase activity, with a kcat of 0.17 min-1. The apparent Km for GTP, as measured in the GTP hydrolysis reaction, was determined to be 4 microM. A chromatography system was established to measure nickel insertion into hydrogenase 3 from E. coli and to determine the effects of lesions in hypB. Nickel appears to be associated only with the processed large subunit of hydrogenase 3 in the wild type, and hypB mutants accumulate the precursor form of this subunit, which is devoid of nickel. The results are discussed in terms of a model in which HYPB is involved in nickel donation to the hydrogenase apoprotein and in which GTP hydrolysis is thought to reverse the interaction between either HYPB or another nickel-binding protein and the hydrogenase apoprotein after the nickel has been released.

The hyp operon gene products are required for the maturation of catalytically active hydrogenase isoenzymes in Escherichia coli

The hyp operon of Escherichia coli comprises several genes which are required for the synthesis of all three hydrogenase isoenzymes. Deletions were introduced into each of the hypA-E genes, transferred to the chromosome and the resulting mutants were analysed for hydrogenase 1, 2 and 3 activity. The products of three of the genes, hypB, hypD and hypE were found to be essential for the synthesis of all three hydrogenase isoenzymes. A defect in hypB, as previously observed, could be complemented by high nickel concentrations in the medium, whereas the effects of mutants in the other genes could not. Lesions in hypA prevented development of hydrogenase 3 activity, did not influence the level of hydrogenase 1 but led to a considerable increase in hydrogenase 2 activity although the amount of hydrogenase 2 protein was not drastically altered. Lesions in hypC, on the other hand, led to a reduction of hydrogenase 1 activity and abolished hydrogenase 3 activity. HYPA and HYPC, besides being required for hydrogenase 3 formation, therefore may have a function in modulating the activities of the three isoenzymes with respect to each other and adjusting their levels to the requirement imposed by the physiological situation. Mutations in all five hyp genes prevented the apparent processing of the large subunits of all three hydrogenase isoenzymes. It is concluded that the products of the hypA-E genes play a role in nickel incorporation into hydrogenase apoprotein and/or processing of the constituent subunits of this enzyme. The importance of their roles is also reflected in their phylogenetic conservation in distantly related organisms.

Molecular characterization of an operon (hyp) necessary for the activity of the three hydrogenase isoenzymes in Escherichia coli

The 58/59 min region of the Escherichia coli chromosome contains two divergently oriented gene clusters coding for proteins with a function in hydrogenase formation. One cluster (the hyc operon), transcribed counterclockwise with respect to the E. coli chromosome, codes for gene products with a structural role in hydrogenase 3 formation (Böhm et al., 1990). The nucleotide sequence of the divergently transcribed operon (hyp) has been determined. It contains five genes, all of which are expressed in vivo in a T7 promoter/polymerase system, and the sizes of the synthesized products correspond with those predicted from the amino acid sequence. Complementation analysis of previously characterized mutants showed that the hypB, hypC and hypD genes have a function in the formation of all three hydrogenase isoenzymes, lesions in hypB being complemented by high nickel ion concentration in the medium. Prevention of hypBCDE gene expression led to an altered electrophoretic pattern of hydrogenase 1 and 2 constituent subunits, indicating increased chemical or proteolytic subunits, Under fermentative growth conditions, operon expression was governed by an NtrA-dependent promoter lying upstream of hypA working together with an fnr gene product-dependent promoter which was localized within the hypA gene. The latter (operon-internal) promoter is responsible for hypBCDE transcription under non-fermentative conditions when the -24/-12 NtrA-dependent promoter upstream of hypA is silent.