Imaging of 3 bright terrestrial gamma-ray flashes by the atmosphere-space interactions monitor and their parent thunderstorms

The Atmosphere-Space Interactions Monitor (ASIM) on the International Space Station (ISS) includes an instrument designed to geolocate Terrestrial Gamma-ray Flashes (TGF) produced by thunderstorms. It does so with a coded aperture system shadowing the pixelated Low Energy Detector of the Modular X- and Gamma-ray Sensor (MXGS). Additionally, it locates associated lightning flashes with the Modular Multispectral Imaging Array (MMIA). Here we present 3 bright TGFs with very similar duration, fluency and observation distance. The innovative imaging capabilities allow us to determine the TGF position and correlate the TGF-lightning parent event in time and position simultaneously. The accurate position determination and distance to the observer allow us to perform a comparative study of TGF characteristics. These TGFs were produced in association with lightning flashes below the highest cloud tops of developing to mature convective cells. In one event, GLM (Geostationary Lightning Mapper) cloud flash rates were slowing down after the TGF while negative cloud-to-ground flashes suddenly ceased from 10 to 5 min before the TGF. An 8-stroke (strongest: -93 kA) cloud-to-ground flash occurred 31 s before the TGF. Vertical profiles from the ERA5 reanalysis data suggest TGFs may be produced in variety of tropical environments.

Pan-tumor landscape of fibroblast growth factor receptor 1-4 genomic alterations

BACKGROUND

Selective tyrosine kinase inhibitors targeting fibroblast growth factor receptor (FGFR) 1-4 genomic alterations are in development or have been approved for FGFR-altered cancers (e.g. bladder cancer and advanced intrahepatic cholangiocarcinoma). Understanding FGFR inhibitor-resistance mechanisms is increasingly relevant; we surveyed the pan-tumor landscape of FGFR1-4 genomic alterations [short variants (SVs), gene rearrangements (REs), and copy number alterations (CNAs)], including their association with tumor mutational burden (TMB) and the genomic comutational landscape.

PATIENTS AND METHODS

Comprehensive genomic profiling of 355 813 solid tumor clinical cases was performed using the FoundationOne and FoundationOne CDx assays (Foundation Medicine, Inc.) to identify genomic alterations in >300 cancer-associated genes and TMB (determined on ≤1.1 megabases of sequenced DNA).

RESULTS

FGFR1-4 SVs and REs occurred in 9603/355 813 (2.7%), and CNAs in 15 078/355 813 (4.2%) samples. Most common FGFR alterations for bladder cancer, intrahepatic cholangiocarcinoma, and glioma were FGFR3 SVs (1051/7739, 13.6%), FGFR2 REs (618/6641, 9.3%), and FGFR1 SVs (239/11 550, 2.1%), respectively. We found several, potentially clinically relevant, tumor-specific associations between FGFR1-4 genomic alterations and other genomic markers. FGFR3 SV-altered bladder cancers and FGFR1 SV-altered gliomas were significantly less likely to be TMB-high versus unaltered samples. FGFR3 SVs in bladder cancer significantly co-occurred with TERT and CDKN2A/B alterations; TP53 and RB1 alterations were mutually exclusive. In intrahepatic cholangiocarcinoma, FGFR2 REs significantly co-occurred with BAP1 alterations, whereas KRAS, TP53, IDH1, and ARID1A alterations were mutually exclusive. FGFR1 SVs in gliomas significantly co-occurred with H3-3A and PTPN11 alterations, but were mutually exclusive with TERT, EGFR, TP53, and CDKN2A/B alterations.

CONCLUSIONS

Overall, our hypothesis-generating findings may help to stratify patients in clinical trials and guide optimal targeted therapy in those with FGFR alterations.

Psychosocial and biological predictors of resident physician burnout

BACKGROUND

A high proportion of health professionals in training suffer from work-related stress and may develop a burnout syndrome.

OBJECTIVES

To study the incidence of burnout after the first year of residency in a teaching hospital and to identify baseline psychological, psychosocial work conditions, and biological risk factors.

METHODOLOGY

We assessed the following in a prospective cohort of residents at baseline (first month residence) and after 1 year: background factors (socio-demographics, psychiatric history), perceived stress score (Perceived Stress Scale), Maslach Burnout Inventory score, and psychosocial factors (Job Content Questionnaire). Blood samples were obtained to study serum cortisol, IL-6, and TNF-α concentrations. The cumulative incidence was modelled by multivariate log-binomial regression analysis.

RESULTS

We included 71 participants with a female majority (64.8%), age 26.4 (2.65) years, psychiatric history in 20%, and burnout in 13%. Among those without burnout initially (N = 59), it had developed by 1 year in 22% of residents. Increased job demand (RR = 1.259, 95%CI = 1.019-1.556, p = 0.033) and decreased cortisol levels (RR = 0.877, 95%CI = 0.778-0.989, p = 0.032) predicted burnout after 1 year of residency among medical trainees.

CONCLUSION

Burnout syndrome develops in 22% of residents by 1 year of training and can be predicted by increased work demands and decreased cortisol levels.

Gigantic jet discharges evolve stepwise through the middle atmosphere

In 2002 it was discovered that a lightning discharge can rise out of the top of tropical thunderstorms and branch out spectacularly to the base of the ionosphere at 90 km altitude. Several dozens of such gigantic jets have been recorded or photographed since, but eluded capture by high-speed video cameras. Here we report on 4 gigantic jets recorded in Colombia at a temporal resolution of 200 µs to 1 ms. During the rising stage, one or more luminous steps are revealed at 32-40 km, before a continuous final jump of negative streamers to the ionosphere, starting in a bidirectional (bipolar) fashion. The subsequent trailing jet extends upward from the jump onset, with a current density well below that of lightning leaders. Magnetic field signals tracking the charge transfer and optical Geostationary Lightning Mapper data are now matched unambiguously to the precisely timed final jump process in a gigantic jet.

The situation of vaccines for the prevention of infections in adults: An opinion paper on the situation in Spain

The childhood immunization schedule is well known and generally well implemented in developed countries. For various reasons, the same is not true of vaccines aimed at preventing infections in adults, in which vaccination coverage is incomplete and generally very deficient. In order to assess the situation of adult vaccination in Spain, the Fundación de Ciencias de la Salud has brought together a series of experts in different fields, including doctors, nurses, representatives of patient associations, health managers and economists, health authorities and journalists to deal with this issue. The format was that of a round table in which a series of questions previously formulated by the coordinators were to be answered and debated. The document presented is not an exhaustive review of the topic, nor is it intended to make recommendations, but only to give a multidisciplinary opinion on topics that could be particularly debatable or controversial. The paper reviews the main vaccine-preventable adult diseases, their clinical and economic impact, the possibilities of reducing them with vaccination programmes and the difficulties in carrying them out. The role of nursing, pharmacy services, patient associations and the health administration itself in changing the current situation was discussed. Prospects for new vaccines were discussed and we speculated on the future in this field. Finally, particularly relevant ethical aspects in decision-making regarding vaccination were discussed, which must be faced by both individuals and states. We have tried to summarize, at the end of the presentation of each question, the environment of opinion that was agreed with all the members of the table.

Metabolomics applied to the discovery of tuberculosis and diabetes mellitus biomarkers

Tuberculosis (TB) and diabetes mellitus Type 2 (DM2) are two diseases as ancient as they are harmful to human health. The outcome for both diseases in part depends on immune and metabolic individual responses. DM2 is increasing yearly, mainly due to environmental, genetic and lifestyle habits. There are multiple evidence that DM2 is one of the most important risk factor of becoming infected with TB or reactivating latent TB. Mass spectrometry-based metabolomics is an important tool for elucidating the metabolites and metabolic pathways that influence the immune responses to M. tuberculosis infection during diabetes. We provide an up-to-date review highlighting the importance and benefit of metabolomics for identifying biomarkers as candidate molecules for diagnosis, disease activity or prognosis.

Tuberculosis and cigarette smoke exposure: An update of in vitro and in vivo studies

Tuberculosis (TB) has been declared the first cause of death by an infectious agent. Annually, 10.4 million people suffer active TB. Most infected individuals live in low-income countries, where social and economic conditions enhance the dissemination and progression of the disease. These countries have a high percentage of smokers. Thousands of studies have linked cigarette smoke (CS) with increased risk of many diseases, such as cancer and lung diseases. Numerous in vitro studies have been conducted to evaluate the general and specific toxic effects of CS in lung immune function. Smoke exposure increases the risk of TB development three-fold. However, until now, only few animal studies have been performed to analyze the association between smoke and TB. In the present work, we review in vitro and in vivo studies whose aim was to analyze the molecular basis of TB susceptibility caused by exposure to CS.

Using radio astronomical receivers for molecular spectroscopic characterization in astrochemical laboratory simulations: A proof of concept

We present a proof of concept on the coupling of radio astronomical receivers and spectrometers with chemical reactors and the performances of the resulting setup for spectroscopy and chemical simulations in laboratory astrophysics. Several experiments including cold plasma generation and UV photochemistry were performed in a 40 cm long gas cell placed in the beam path of the Aries 40 m radio telescope receivers operating in the 41-49 GHz frequency range interfaced with fast Fourier transform spectrometers providing 2 GHz bandwidth and 38 kHz resolution. The impedance matching of the cell windows has been studied using different materials. The choice of the material and its thickness was critical to obtain a sensitivity identical to that of standard radio astronomical observations. Spectroscopic signals arising from very low partial pressures of CH₃OH, CH₃CH₂OH, HCOOH, OCS, CS, SO₂ (<10^-3 mbar) were detected in a few seconds. Fast data acquisition was achieved allowing for kinetic measurements in fragmentation experiments using electron impact or UV irradiation. Time evolution of chemical reactions involving OCS, O₂ and CS₂ was also observed demonstrating that reactive species, such as CS, can be maintained with high abundance in the gas phase during these experiments.

Mitochondrial DNA phylogeography of least cisco Coregonus sardinella in Alaska

This study presents the first detailed analysis of the mitochondrial DNA diversity of least cisco Coregonus sardinella in Alaska using a 678 bp segment of the control region (D-loop) of the mitochondrial genome. Findings suggest that the history of C. sardinella in Alaska differs from that of other species of Coregonus present in the state and surrounding regions. The examined populations of C. sardinella are genetically diverse across Alaska. Sixty-eight distinct mitochondrial haplotypes were identified among 305 individuals sampled from nine locations. The haplotype minimum spanning network and phylogeny showed a modest level of geographic segregation among haplotypes, suggesting high levels of on-going or recent connectivity among distant populations. Observed Φ_ST values and the results of homogeneity and AMOVAs indicate incipient genetic differentiation between aggregations in three broad regional groups. Sites north of the Brooks Range formed one group, sites in the Yukon and Selawik Rivers formed a second group and sites south of the Yukon drainage formed the third group. Overall, the sequence data showed that a large proportion of mtDNA genetic variation in C. sardinella is shared across Alaska, but this variation is not homogeneously distributed across all regions and for all haplotype groups.

Search for triboson [Formula: see text] production in pp collisions at [Formula: see text] [Formula: see text] with the ATLAS detector

This paper reports a search for triboson [Formula: see text] production in two decay channels ([Formula: see text] and [Formula: see text] with [Formula: see text]) in proton-proton collision data corresponding to an integrated luminosity of 20.3 [Formula: see text] at a centre-of-mass energy of 8 [Formula: see text] with the ATLAS detector at the Large Hadron Collider. Events with exactly three charged leptons, or two leptons with the same electric charge in association with two jets, are selected. The total number of events observed in data is consistent with the Standard Model (SM) predictions. The observed 95% confidence level upper limit on the SM [Formula: see text] production cross section is found to be 730 fb with an expected limit of 560 fb in the absence of SM [Formula: see text] production. Limits are also set on WWWW anomalous quartic gauge couplings.

Analysis of temperature on the surface of the wrist due to repetitive movements using sensory thermography

This study examines changes in body temperature generated in the wrist area through sensory thermography technique because of highly repetitive movements, proving with this technique that there is a decreased ability to perform muscular work, and thereby assess possible pathologies of Cumulative Trauma Disorders (CTDs).

METHODS

Two healthy right-handed individuals, who performed repetitive work, emulating an operation of the textile industry for three days, generated DTA in the area of the wrist. The evaluation time was of 3 hours 30 minutes in a controlled temperature between 20 and 25°C, 20 minutes stabilization time at the beginning and end of the operation.

RESULTS

The maximum temperatures reached were on the right wrist (RW) of 35. 078°C over a period of 1 hour 41 minutes 52 seconds; and on the left wrist (LR), 34.663°C over a period of 2 hours 42 minutes 51 seconds, detected discomfort in their right shoulder and wrist in the time range which identified the highest temperatures. It was shown that the data does not fit a normal distribution for RW and LW; the data fit the three- parameters Weibull distribution for WR and LW with a correlation coefficient between 0.93 to 0.99.

Predicting response and survival in chemotherapy-treated triple-negative breast cancer

BACKGROUND

In this study, we evaluated the ability of gene expression profiles to predict chemotherapy response and survival in triple-negative breast cancer (TNBC).

METHODS

Gene expression and clinical-pathological data were evaluated in five independent cohorts, including three randomised clinical trials for a total of 1055 patients with TNBC, basal-like disease (BLBC) or both. Previously defined intrinsic molecular subtype and a proliferation signature were determined and tested. Each signature was tested using multivariable logistic regression models (for pCR (pathological complete response)) and Cox models (for survival). Within TNBC, interactions between each signature and the basal-like subtype (vs other subtypes) for predicting either pCR or survival were investigated.

RESULTS

Within TNBC, all intrinsic subtypes were identified but BLBC predominated (55-81%). Significant associations between genomic signatures and response and survival after chemotherapy were only identified within BLBC and not within TNBC as a whole. In particular, high expression of a previously identified proliferation signature, or low expression of the luminal A signature, was found independently associated with pCR and improved survival following chemotherapy across different cohorts. Significant interaction tests were only obtained between each signature and the BLBC subtype for prediction of chemotherapy response or survival.

CONCLUSIONS

The proliferation signature predicts response and improved survival after chemotherapy, but only within BLBC. This highlights the clinical implications of TNBC heterogeneity, and suggests that future clinical trials focused on this phenotypic subtype should consider stratifying patients as having BLBC or not.

Synthetic microvessels

The microvasculature is an immense organ that defines the environmental conditions within tissues in both health and disease, and is vital for the proper functions of all tissues. Here, we describe existing tools to study vascular cell function and our work using one platform of in vitro microvessels, which we employed to study vessel structure and remodeling, endothelial barrier function, angiogenesis, interactions between endothelial cells and perivascular cells, interactions between blood cells and the endothelium, and microvascular thrombosis. We also briefly discuss the potential future applications of these platforms in biology and medicine.

Evaluation of by-products from the biodiesel industry as fermentation feedstock for poly(3-hydroxybutyrate-co-3-hydroxyvalerate) production by Cupriavidus necator

Utilization of by-products from oilseed-based biodiesel production (crude glycerol, rapeseed meal hydrolysates) for microbial polyhydroxyalkanoate (PHA) production could lead to the replacement of expensive carbon sources, nutrient supplements and precursors for co-polymer production. Batch fermentations in shake flasks with varying amounts of free amino nitrogen led to the production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P(3HB-co-3HV)) with a 2.8-8% 3HV content. Fed-batch fermentations in shake flasks led to the production of 10.9g/L P(3HB-co-3HV) and a 55.6% P(3HB-co-3HV) content. NaCl concentrations between 2 and 6g/L gradually became inhibitory to bacterial growth and PHA formation, whereas in the case of K(2)SO(4), the inhibitory effect was observed only at concentrations higher than 20g/L. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and nuclear magnetic resonance ((13)C NMR) demonstrated that the incorporation of 3HV into the obtained P(3HB-co-3HV) lowered glass transition temperature, crystallinity and melting point as compared to polyhydroxybutyrate. Integrating PHA production in existing oilseed-based biodiesel plants could enhance the viability and sustainability of this first generation biorefinery.

Proteome changes in the myocardium of experimental chronic diabetes and hypertension: role of PPARα in the associated hypertrophy

Diabetes with or without the presence of hypertension damages the heart. However, there is currently a lack of information about these associated pathologies and the alteration of linked proteins. For these reasons, we were interested in the potential synergistic interaction of diabetes and hypertension in the heart, focusing on the proteome characterization of the pathological phenotypes and the associated hypertrophic response. We treated normotensive and spontaneously hypertensive (SHR) rats with either streptozotocin or vehicle. After 22weeks, type-I diabetic (DM1), SHR, SHR/DM1 and control left-ventricles were studied using proteomic approaches. Proteomics revealed that long-term DM1, SHR and SHR/DM1 rats exhibited 24, 53 and 53 altered proteins in the myocardia, respectively. DM1 myocardium showed over-expression of apoptotic and cytoskeleton proteins, and down-regulation of anti-apoptotic and mitochondrial metabolic enzymes. In both SHR and SHR/DM1 these changes were exacerbated and free fatty-acid (FFA) ß-oxidation enzymes were additionally decreased. Furthermore, SHR/DM1 hearts exhibited a misbalance of specific pro-hypertrophic, anti-apoptotic and mitochondrial ATP-carrier factors, which could cause additional damage. Differential proteins were validated and then clustered into different biological pathways using bioinformatics. These studies suggested the implication of FFA-nuclear receptors and hypertrophic factors in these pathologies. Although key ß-oxidation enzymes were not stimulated in DM1 and hypertensive hearts, peroxisome proliferator-activated receptors-α (PPARα) were potentially activated for other responses. In this regard, PPARα stimulation reduced hypertrophy and pro-hypertrophic factors such as annexin-V in high-glucose and angiotensin-II induced cardiomyocytes. Thus, activation of PPARα could reflect a compensatory response to the metabolic-shifted, apoptotic and hypertrophic status of the hypertensive-diabetic cardiomyopathy.

Patterns of blood product use among patients with myelodysplastic syndrome

BACKGROUND AND OBJECTIVES

Most patients with myelodysplastic syndrome (MDS) require blood product support to manage the severe anaemias, which frequently accompany MDS. Our objective was to show the feasibility of linking the Surveillance, Epidemiology and End Results (SEER) database with records from Puget Sound Blood Center (PSBC) to characterize blood product use over time in successive cohorts of patients with MDS.

MATERIALS AND METHODS

We identified patients with MDS in the SEER registry. The cohort was then linked to PSBC records to discern blood product use.

RESULTS

Included in the analysis were 783 patients with MDS entered in the SEER database from 2001 to 2007 for whom data were also available in the PSBC database. Among patients with MDS who received transfusions, 97% received packed red blood cells; 52% received platelets. The proportion of patients with MDS receiving blood products declined from 2001 to 2007.

CONCLUSION

These data show a recent decline in blood product use for patients with MDS. Future studies are needed to further evaluate the reasons for this finding, specifically exploring the impact of newer medications on blood product use in patients with MDS.

The platelet glycoprotein Ib-IX-V complex anchors lipid rafts to the membrane skeleton: implications for activation-dependent cytoskeletal translocation of signaling molecules

BACKGROUND

The glycoprotein (GP) Ib-IX-V complex attaches platelets to areas of endothelial damage by binding von Willebrand factor (VWF), an interaction that transmits intracellular activation signals. These signals require that the complex associates with both lipid rafts and the membrane cytoskeleton, but it is not clear whether the same GPIb-IX-V subpopulation associates with both structures.

OBJECTIVES

To determine which subpopulation of GPIb-IX-V associates with lipid rafts, and the consequences of that interaction.

METHODS

We analyzed the content of proteins (particularly the GPIb-IX-V complex) and lipids in rafts from detergent lysates of platelets before and after removal of the actin cytoskeleton alone or both the actin cytoskeleton and membrane skeleton (by successive centrifugations of 15,800 x g and 100,000 x g).

RESULTS

In unstimulated platelets, little raft-associated GPIb-IX-V sedimented with the actin skeleton; most was removed by sedimentation of the membrane skeleton. The Src family kinase Lyn followed the same pattern. In VWF-activated platelets, almost all of the GPIb-IX-V complex and Lyn in rafts sedimented with the actin cytoskeleton, consistent with a previously described crosslinking of the membrane and actin skeletal structures following platelet activation. Disruption of the GPIbalpha-filamin linkage with N-ethylmaleimide prevented depletion of raft-associated GPIb-IX-V by skeletal sedimentation. Not all raft-associated proteins and lipids followed this pattern.

CONCLUSION

These results suggest that the raft association and cytoskeletal linkage of the GPIb-IX-V complex are interrelated, and both are required for optimal receptor function, perhaps because raft association attracts signaling proteins and membrane skeletal association allows these proteins to move en masse to new locations.

Binding of platelet glycoprotein Ibbeta through the convex surface of leucine-rich repeats domain of glycoprotein IX

BACKGROUND

The mechanism of assembly of the platelet glycoprotein (GP) Ib-IX complex from GPIbalpha, GPIbbeta and GPIX subunits is not entirely clear. In this complex, ectodomains of both GPIbbeta and GPIX subunits contain two leucine-rich repeats (LRR) and share high sequence similarity. However, they differ noticeably in stability, hampering further analysis of their interaction.

OBJECTIVES AND METHODS

Guided by analysis of the LRR structure, we report a well-folded Ibbeta/IX chimera and its usage in dissecting GPIX function.

RESULTS

In this chimera, three non-contiguous sequences that may constitute the putative convex surface of the GPIbbeta ectodomain are replaced by their GPIX counterparts. Like GPIbbeta but unlike GPIX ectodomain, it can secrete from transfected Chinese hamster ovary cells and fold into a stable conformation. Furthermore, replacing the ectodomain in GPIX with the Ibbeta/IX chimera, but not the GPIbbeta ectodomain, preserved its interaction with GPIbbeta as demonstrated by its native-like GPIbbeta-induced increase in surface expression and coimmunoprecipitation.

CONCLUSIONS

The putative convex surface of the LRR domain in GPIX is sufficient, in the context of full-length subunit, to mediate its association with GPIbbeta.

Trypanosoma cruzi strains, Tulahuen 2 and Y, besides the difference in resistance to oxidative stress, display differential glucose-6-phosphate and 6-phosphogluconate dehydrogenases activities

The drugs currently available for Chagas'disease treatment are unsatisfactory due to limited efficacy and toxic side effects, making the search for more specific pharmacological agents a priority. The components of the Trypanosoma cruzi trypanothione-dependent antioxidant system have been pointed out as potential chemotherapeutic targets for the development of more specific drugs. To work properly, this system must have a current supply of NADPH, provided by glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD). Here, we compare two T. cruzi strains, Tulahuen 2 and Y, regarding growth rate, cytosolic tryparedoxin peroxidase (TcCPX) concentration and pentose phosphate pathway dehydrogenases activities. Tulahuen 2 cells show higher values as compared to the Y strain when the following parameters are compared: TcCPX concentration, resistance to H2O2, growth index and G6PD activity. Different patterns of G6PD and 6PGD activities were observed among strains along the growth curve and when cells were challenged with H2O2. These data reinforce the heterogeneity within T. cruzi populations and also the importance of G6PD in protecting the parasite against reactive oxygen species.

Microvesicle-associated tissue factor and Trousseau's syndrome

BACKGROUND

Trousseau's syndrome is a prothrombotic state associated with malignancy that is poorly understood pathophysiologically.

METHODS AND RESULTS

Here we report studies on the blood of a 55-year-old man with giant-cell lung carcinoma who developed a severe form of Trousseau's syndrome. His clinical course was dominated by an extremely hypercoagulable state. Despite receiving potent antithrombotic therapy, he suffered eleven major arterial and venous thrombotic events over a 5 month period. We examined the patient's blood for tissue factor (TF), the major initiator of coagulation, and found its concentration in his plasma to be forty-one-fold higher than the mean concentration derived from testing of 16 normal individuals.

CONCLUSION

Almost all of the TF in the patient's plasma was associated with cell-derived microvesicles, likely shed by the cancer cells.

Turnera ulmifolia L. (Turneraceae): preliminary study of its antioxidant activity

Turnera ulmifolia L. is used in Brazilian folk medicine as an anti-inflammatory. Since this activity may be correlated with the presence of antioxidant compounds, a leaf extract was evaluated for its radical scavenging capacity (RSC). The in vitro RSC of a 50% hydroethanolic (HE) extract was evaluated by beta-carotene/linoleic acid coupled oxidation system for the inhibition of oxidation and the lipid peroxidation inhibition in rat brain homogenates, using thiobarbituric acid reactive substances (TBARS) and chemiluminescence (CL). Results indicated, through peroxidation suppression, that this extract exhibited greater antioxidative activity (77.4% +/- 10%) than alpha-tocopherol (58.4% +/- 3.7%). TBARS and CL inhibition was concentration-dependent and Q(1/2) values were 8.2 and 6.0 microg/mL for TBARS and CL, respectively. For alpha-tocopherol these values were 7.1 microg/mL (TBARS) and 9.8 microg/mL (CL). Phenolic compounds may be responsible for this antioxidant capacity.

Efficacy and Safety of Sclerotherapy Using Polidocanol Foam: A Controlled Clinical Trial

OBJECTIVE

To assess the efficacy and safety of sclerotherapy performed with polidocanol foam compared to liquid polidocanol.

METHODS

Controlled clinical trial with 1 year follow up in which each patient acted as his/her own control. A total of 75 patients (six men and 69 women) with reticular or postoperative varices were enrolled and sclerotherapy was performed with liquid and with foam (Tessari method) using the same quantity of sclerosant for homogeneous varicose regions, to a total of 150 procedures. The sclerosant concentration was adjusted according to the vein diameter as assess by ultrasonography. The foam group was given 50% lower concentrations of sclerosant than liquid sclerosant group. Clinical assessment (pain, inflammation, pigmentation) and ultrasound examination (diameter of the lumen and length of sclerosed vein) were carried out at 15, 30, 90, and 365 days.

RESULTS

Foam allowed complete sclerosis at 90 days in 94.4% of patients compared with 53% for liquid (p<.001) and also allowed a more extensive venous sclerosis (10.1cm compared with 7.2 cm; p<.001). Pain, signs of inflammation, and pigmentation appeared more often with foam sclerosis, with significant difference. The degree of satisfaction was similar for both techniques.

CONCLUSIONS

Efficacy of venous sclerosis with foam seems to be greater than with liquid although there is a higher risk of minor secondary effects.

Phosphorylation and subcellular localization of transmissible gastroenteritis virus nucleocapsid protein in infected cells

The nucleocapsid (N) protein is the only phosphorylated structural protein of the coronavirus Transmissible gastroenteritis virus (TGEV). The phosphorylation state and intracellular distribution of TGEV N protein in infected cells were characterized by a combination of techniques including: (i) subcellular fractionation and analysis of tryptic peptides by two-dimensional nano-liquid chromatography, coupled to ion-trap mass spectrometry; (ii) tandem mass-spectrometry analysis of N protein resolved by SDS-PAGE; (iii) Western blotting using two specific antisera for phosphoserine-containing motifs; and (iv) confocal microscopy. A total of four N protein-derived phosphopeptides were detected in mitochondria–Golgi–endoplasmic reticulum–Golgi intermediate compartment (ERGIC)-enriched fractions, including N-protein phosphoserines 9, 156, 254 and 256. Confocal microscopy showed that the N protein found in mitochondria–Golgi–ERGIC fractions localized within the Golgi–ERGIC compartments and not with mitochondria. Phosphorylated N protein was also present in purified virions, containing at least phosphoserines 156 and 256. Coronavirus N proteins showed a conserved pattern of secondary structural elements, including six β-strands and four α-helices. Whilst serine 9 was present in a non-conserved domain, serines 156, 254 and 256 were localized close to highly conserved secondary structural elements within the central domain of coronavirus N proteins. Serine 156 was highly conserved, whereas no clear homologous sites were found for serines 254 and 256 for other coronavirus N proteins.

Receptors, rafts, and microvesicles in thrombosis and inflammation

Hemostasis at sites of blood vessel injury and its pathologic counterpart, thrombosis, involve a complex interplay between several blood elements: soluble proteins of the blood coagulation system, blood cells (most prominently platelets) and cell fragments, and elements of the vessel wall (endothelial cells and, at sites of injury, the exposed matrix and deeper cellular components). In this review, we focus on ways in which specialized membrane microdomains known as lipid rafts are involved in various phases of hemostasis and thrombosis.

Identification of Proteins Expressing Differences among Isolates of Meloidogyne spp. (Nematoda: Meloidogynidae) by Nano-Liquid Chromatography Coupled to Ion-Trap Mass Spectrometry

Total protein variation (up to ninety-five different positions) was revealed by two-dimensional electrophoresis (2-DE) in 18 isolates from populations of M. arenaria (6 isolates), M. incognita (10), M. javanica (1) plus an unclassified isolate in a previously reported study. Isolates of M. arenaria, M. javanica, Meloidogyne sp., and M. incognita formed two separate groups defined on the basis of two sets of protein positions that could be considered as diagnostic characters, but we could not identify these proteins by MALDI-TOF. To identify these marker positions, nano-liquid chromatography as peptides separation method was coupled to an ion-trap mass spectrometer for induced real-time fragmentation of eluted peptides. Group diagnostic proteins for M. incognita and M. arenaria were in-gel digested and on line analyzed by tandem mass spectrometry (LC-MS/MS). Six proteins out of seven selected spots were unambiguously identified by the analysis of the corresponding MS/MS (MS2) spectrum from parent ions fragmentation: Actin, Enolase, CG3752-PA protein similar to Aldehyde Dehydrogenase, HSP-60 and Translation initiation factor elF-4A. In M. incognita sample, de novo sequencing experiment of doubly charged ion at m/z=936.9 Da in spot 29 identified as enolase, reveals three residue substitutions (K to T, N to T, and D to E) when tentative sequence was compared with that of Anisakis simplex and Onchocerca volvulus enolase, thus three SNPs (single nucleotide polymorphisms) were also possibly identified.

Liver transplantation in infants weighing under 7 kilograms: management and outcome of PICU

Liver transplantation (LT) is an established treatment for children with acute and chronic liver failure. Some reports suggest that infants under the age of 1 yr and children weighing under 13 kg are high-risk groups associated with less satisfactory results. This report describes our experience during the pediatric intensive care unit stay of 16 infants weighing <7 kg who received LT. We reviewed the records of 16 infants with median age 7.4 months and median weight 5.8 kg, who received 18 liver allografts, nine whole and nine reduced. We also reviewed the use of adrenergic agonist agents, anti-infectious agents, antihypertensive agents, diuretics, immunosuppression protocol, sedation-analgesia agents, others agents (prostaglandin E(1), heparin and dipyridamole), diagnosis and management of rejection episodes, follow-up examination, nutrition and outcome. Mean peri-operative blood transfusions were 204 mL/kg, 188 mL/kg of plasma and 36 mL/kg of platelets; mean operative time was 5 h. Primary abdominal wound closure was possible in nine patients. Median initial intensive care unit stay was 18 days. Reasons for an initial stay of more than 18 days were retransplantation (1), gastrointestinal bleeding (2), paralytic ileus and atelectasis (2), septic shock (2), diaphragmatic paralysis, renal impairment and acute respiratory distress syndrome (2). Mean requirement for artificial ventilation was 168 h. Mean use of dobutamine, prostaglandin E(1) and dopamine was 3.3, 7.5 and 8.8 days, respectively. Parenteral nutrition was started at a mean of 48 h and oral food intake was started at a mean of 72 h. The most frequent complications were infection, atelectasis, gastrointestinal bleeding, acute renal failure and hepatic artery thrombosis. Four children required six re-explorations and two received retransplantation. Mean overall survival rate was 82% and graft survival was 72%. Weight alone (under 7 kg) should not be considered as a contraindication for LT. The survival rate of children post-LT is excellent regardless of graft type.

The use of reverse transcription-PCR for the diagnosis of X-linked chronic granulomatous disease

Chronic granulomatous disease (CGD) is an inherited disorder of the innate immune system characterized by a defective oxidative burst of phagocytes and subsequent impairment of their microbicidal activity. Mutations in one of the NADPH-oxidase components affect gene expression or function of this system, leading to the phenotype of CGD. Defects in gp91-phox lead to X-linked CGD, responsible for approximately 70% of CGD cases. Investigation of the highly heterogeneous genotype of CGD patients includes mutation analysis, Northern blot or Western blot assays according to the particular case. The aim of the present study was to use reverse transcription (RT)-PCR for the analysis of molecular defects responsible for X-linked CGD in eight Brazilian patients and to assess its potential for broader application to molecular screening in CGD. Total RNA was prepared from Epstein B virus-transformed B-lymphocytes and reverse transcribed using random hexamers. The resulting cDNA was PCR-amplified by specific and overlapping pairs of primers designed to amplify three regions of the gp91-phox gene: exons 1-5, 3-9, and 7-13. This strategy detected defective gp91-phox expression in seven patients. The RT-PCR results matched clinical history, biochemical data (nitroblue tetrazolium or superoxide release assay) and available mutation analysis in four cases. In three additional cases, RT-PCR results matched clinical history and biochemical data. In another case, RT-PCR was normal despite a clinical history compatible with CGD and defective respiratory burst. We conclude that this new application of RT-PCR analysis--a simple, economical and rapid method--was appropriate for screening molecular defects in 7 of 8 X-linked CGD patients.

Von Willebrand factor present in fibrillar collagen enhances platelet adhesion to collagen and collagen-induced platelet aggregation

We examined the basis of the differences observed between different collagen preparations in their ability to aggregate platelets and support their adhesion under flow. As in previous studies, we found fibrillar collagen to be 10-fold more potent than acid-soluble collagen in inducing platelet aggregation and found that acid-soluble collagen did not support the adhesion of washed platelets under flow. Further, platelets in whole blood adhered to surfaces coated with either fibrillar or acid-soluble collagen, but thrombi formed faster and grew larger on fibrillar collagen. As a possible basis for this difference, we found that fibrillar collagen, but not acid-soluble collagen, contains a substantial quantity of von Willebrand factor (VWF), as demonstrated by enzyme-linked immunosorbent assay and by the ability of fibrillar collagen to support the adhesion of VWF antibody-coated beads and to agglutinate GPIb-IX-V complex-expressing Chinese hamster ovary cells. Supporting a role for VWF in collagen-induced platelet aggregation, aggregation induced by acid-soluble collagen was greatly enhanced by added VWF. Further, platelet aggregation by fibrillar collagen was partially blocked by a GPIbalpha antibody that inhibits the GPIb-VWF interaction. Taken together, these results suggest that much of the difference in prothrombotic potency of different collagens is directly related to their differences in VWF content. This probably accounts for the different conclusions made regarding the relative importance of different direct and indirect collagen receptors in collagen-dependent platelet functions and further emphasizes the close synergistic roles of the GPIb-IX-V complex and the collagen receptors GPVI and alpha2beta1 in supporting platelet adhesion.

Prognostic significance of the p185 protein in colorectal cancer

The amplification and/or overexpression of the c-erbB-2/neu oncogene may play a role in tumor development and progression. The aim of this prospective study was to evaluate the prognostic value of p185 protein in colorectal cancer using immunohistochemical techniques. We analyzed 106 colorectal tumor tissue specimens from patients who had been operated on by the same surgeon and subjected to a median follow-up of 3 years. Thirty-three per cent of patients showed p185 overexpression related to an advanced stage of the disease. In patients with adenocarcinoma tumors of the colon without distant metastases, p185 detection was found to be of clinical prognostic relevance (p = 0.06).

Glycoprotein Ib-IX-mediated activation of integrin alpha(IIb)beta(3): effects of receptor clustering and von Willebrand factor adhesion

The interaction between the platelet glycoprotein (GP) Ib-IX complex and von Willebrand factor (VWF) initiates both hemostasis and pathological thrombosis. This interaction is not only the first adhesive event of platelets at sites of vessel injury, but also facilitates fibrinogen binding to alpha(IIb)beta(3), which subsequently results in platelet aggregation. Since it has been suggested that GP Ib-IX clustering may promote platelet activation, we investigated the effect of such clustering on both VWF-GP Ib-IX and fibrinogen-alpha(IIb)beta(3) bonds using optical tweezers. In our system, fusion of tandem repeats of FK506-binding protein (FKBP) to the cytoplasmic tail of the GP IX subunit of the GP Ib-IX complex allowed subsequent receptor clustering within the plasma membrane by the bivalent, cell-permeant small molecule ligand AP20187. We measured binding forces between polystyrene beads coated with either plasma-derived VWF or the VWF A1 domain and GP Ib-IX(FKBP)2, and those between fibrinogen-coated beads and alpha(IIb)beta(3) expressed on Chinese hamster ovary cells. The minimal detachment force between GP Ib-IX(FKBP)(2) and A1 or plasma-derived VWF doubled after AP20187 was added. The binding force between immobilized fibrinogen and alpha(IIb)beta(3) was not changed by the clustering agent; however, the strength of single fibrinogen-alpha(IIb)beta(3) bonds increased significantly after ligation of GP Ib-IX(FKBP)(2) by A1. These results demonstrate that GP Ib-IX clustering increases the overall strength of its interaction with VWF. Furthermore, signals from GP Ib-IX can activate alpha(IIb)beta(3), thereby increasing the strength of its interaction with fibrinogen.

Sulfatides inhibit platelet adhesion to von Willebrand factor in flowing blood

Sulfatides are sulfated glycosphingolipids present on cell surfaces that bind to adhesive proteins such as von Willebrand factor (VWF), P-selectin, laminin and thrombospondin. Previous studies have localized the sulfatide-binding site of VWF to amino acid residues Gln626-Val646 in the A1 domain. The A1 domain also contains the binding site for platelet glycoprotein Ib (GP Ib), a site that has been reported to be distinct from the sulfatide-binding site. In this study, we analyzed the interaction of sulfatides with VWF and its effect on GP Ib-mediated platelet adhesion under flow conditions. Recombinant VWF A1 domain (rVWF-A1) bound specifically and saturably to sulfatides (half-maximal concentration of approximately 12.5 microg mL(-1)), binding that was blocked by dextran sulfate (IC(50) approximately equal to 100 microg mL(-1)) but not by heparin at concentrations up to 100 U mL(-1). Furthermore, sulfatides (125 microg mL(-1)) prevented the adhesion of platelets or glycocalicin-coupled polystyrene beads to a rVWF-A1-coated surface under high shear stress. In addition, plasma VWF prebound to a sulfatide-coated surface failed to support subsequent platelet adhesion. These results provide firm evidence that sulfatides bind the VWF A1 domain at a site overlapping the GP Ib-binding site.

Portable pilot plant for evaluating marine biofouling growth and control in heat exchangers-condensers

Biofouling frequently involves a serious impediment to achieving optimum operating conditions in heat exchangers-condensers. The economic coat and energy losses associated with this phenomenon are significant and the environmental impact of biocides must satisfy stringent regulations. A portable pilot plant has been designed in order to carry out in-situ experimental study as biofilm is formed under thermal and hydrodynamically controlled conditions. The pilot plant has an automatic monitoring, control and data acquisition system, which automatically processes data from indirect measure of fouling in terms of increased fluid frictional and heat transfer resistances. A particular method is used and proposed for direct measuring and biofilm characterization. Once we know the actual film thickness, we can calculate the effective thermal conductivity of the layer by using the appropriate heat transfer equations.

Protein variability in Meloidogyne spp. (Nematoda:Meloidogynidae) revealed by two-dimensional gel electrophoresis and mass spectrometry

Total protein variation as revealed by two-dimensional electrophoresis (2D-E) was studied in 18 isolates from populations of Meloidogyne arenaria (six isolates), Meloidogyne incognita (10 isolates), and Meloidogyne javanica (one isolate) plus an unclassified isolate. Gels (80 x 60 x 0.75 mm) were silverstained and digitized in order to compare their protein patterns. Optical density and position of protein patterns were measured using statistical cluster analysis and computer-assisted image analysis software. Only those protein stains or positions that were clearly defined (i.e., without background) were considered. The number of positions in gels ranged from 86 to 203. Each of these positions had 95 clearly expressed proteins that were present in at least two replicates for each isolate. Spot position was considered a taxonomical character with two different states: presence (1) and absence (0). Accordingly, genetic distance was estimated among isolates and species, and a phylogenetic tree was constructed following the cladistic approach based on maximum parsimony analysis. Isolates of M. arenaria--M. javanica--Meloidogyne sp. and of M. incognita formed two separate monophyletic groups. Both groups were clearly defined on the basis of two sets of protein positions that can be considered as diagnostic characters. An attempt to identify these proteins by mass spectrometry was made. Group diagnostic proteins for M. incognita and M. arenaria (and for other proteins common to all isolates) were distinguished by protonated mass signals in the MALDI fingerprinting spectrum.

Fast screening method for the determination of angiotensin II receptor antagonists in human plasma by high-performance liquid chromatography with fluorimetric detection

A selective, accurate and precise high-performance liquid chromatographic assay coupled to fluorescence detection was developed for the detection of some angiotensin II receptor antagonists (ARA II): Losartan, Irbesartan, Valsartan, Candesartan cilexetil and its metabolite Candesartan MI. The analytes and the internal standard (bumetanide, a high-ceiling diuretic) were extracted from plasma under acidic conditions by means of solid-phase extraction using C8 cartridges. This procedure allowed recoveries close to 80% for all these drugs excluding Candesartan cilexetil (70%) which presented adsorption processes on glass and plastic walls. The analytes and potential interferences were separated on a reversed-phase column, muBondapak C18, at room temperature. A gradient elution mode was used to carry out the separation, the optimal mobile phase being composed of acetonitrile-5 mM acetate buffer, pH 4, at variable flow-rates (from 1.0 to 1.2 ml/min). Fluorescence detector was set at an excitation wavelength of 250 nm and an emission wavelength of 375 nm. Intra- and inter-day relative standard deviations for all the compounds were lower than 8% except for Losartan (12%) and the method assesses a quite good accuracy (percentage of relative error approximately 6% in most of the cases). The limit of quantitation for these compounds was 3 ng/ml for Candesartan cilexetil and M1, 16 ng/ml for Losartan and 50 ng/ml for Irbesartan and Valsartan, which allows their determination at expected plasma concentration levels. This assay method has been successfully applied to plasma samples obtained from hypertensive patients under clinical studies after oral administration of a therapeutic dose of some of these ARA II compounds.

Transmission of trans effects in dinuclear complexes

The substitution of a terminal hydride ligand in the complexes [Ir(2)(mu-H)(mu-Pz)(2)H(3)(L)P(i)Pr(3))(2)] (L = NCCH(3) (1) or pyrazole (3)) by chloride provokes a significant change in the lability of the L ligand, despite the fact that the substituted hydride and the L ligand lie in opposite extremes of the diiridium(III) complexes. Detailed structural studies of complex 3 and its chloro-trihydride analogue [Ir(2)(mu-H)(mu-Pz)(2)H(2)Cl(HPz)(P(i)Pr(3))(2)] (4) have shown that this behavior is a consequence of the transmission of ligand trans effects from one extreme of the molecule to the other, with the participation of the bridging hydride. Extended Hückel calculations on model diiridium complexes have suggested that such trans effect transmissions are due to the formation of molecular orbitals of sigma symmetry extended along the backbones of the complexes. This is also an expected feature for metal-metal bonded complexes. The feasibility of the transmission of ligand trans effects and trans influences through metal-metal bonds and its relevance to the understanding of both the reactivity and structures of metal-metal bonded dinuclear compounds have been substantiated through structural studies and selected reactions of the diiridium(II) complexes [Ir(2)(mu-1,8-(NH)(2)naphth)I(CH(3))(CO)(2)(P(i)Pr(3))(2)] (isomers 6 and 7) and their cationic derivatives [Ir(2)(mu-1,8-(NH)(2)naphth)(CH(3))(CO)(2)(P(i)Pr(3))(2)](CF(3)SO(3)) (isomers 8 and 9).

Role of Kozak sequence polymorphism of platelet glycoprotein Ibalpha as a risk factor for coronary artery disease and catheter interventions

OBJECTIVES

We sought to determine the role of the -5T/C polymorphism of the platelet glycoprotein (GP) Ibalpha as a potential risk factor for coronary artery disease (CAD) and adverse events complicating a coronary catheter intervention.

BACKGROUND

The platelet GP Ib-IX-V receptor complex plays a crucial role in arterial thrombus formation. The -5T/C polymorphism of GP Ibalpha is associated with increased receptor density.

METHODS

We genotyped 1,000 patients with angiographically confirmed CAD, as well as 1,000 age- and gender-matched control subjects, for this polymorphism by polymerase chain reaction/restriction fragment length polymorphism. Among the patients with CAD, 269 underwent percutaneous transluminal coronary angioplasty (PTCA), 103 underwent directional coronary atherectomy and 278 underwent stenting. This intervention group was followed for a 30-day composite end point of target vessel revascularization, myocardial infarction or death.

RESULTS

Carriers of the -5C allele were significantly over-represented in the group of patients developing acute coronary syndromes (relative risk [RR] 1.43, 95% confidence interval [CI] 1.05 to 1.95, p = 0.02). The -5C allele furthermore predicted an increased risk for developing complications after PTCA (RR 3.75, 95% CI 1.15 to 12.27, p = 0.029).

CONCLUSIONS

The -5C allele of the GP Ibalpha Kozak polymorphism may represent a risk factor in clinical conditions in which thrombosis plays an important role, such as in acute coronary syndromes and in complications after PTCA.

Synthesis of paramagnetic tetranuclear rhodium and iridium complexes with the 2,6-pyridinedithiolate ligand. Redox-induced degradation to diamagnetic triiridium compounds

The tetranuclear complexes [M4(mu-PyS2)2(diolefin)4] [PyS2 = 2,6-pyridinedithiolate; M = Rh, diolefin = cod (1,5-cyclooctadiene) (1), tfbb (tetrafluorobenzo[5,6]bicyclo[2.2.2]octa-2,5,7-triene) (2); M = Ir, diolefin = cod (3), tfbb (4)] exhibit two one-electron oxidations at a platinum disk electrode in dichloromethane at potentials accessible by chemical reagents. The rhodium tetranuclear complexes were selectively oxidized to the monocationic complexes [Rh4(mu-PyS2)2(diolefin)4](+) (1(+), 2(+)) by mild one-electron oxidants such as [Cp2Fe](+) or [N(C6H4Br-4)3](+) and isolated as the PF6(-), BF4(-), and ClO4(-) salts. Silver salts behave as noninnocent one-electron oxidants for the reactions with the rhodium complexes 1 and 2 since they give sparingly soluble coordination polymers. The complex [Ir4(mu-PyS2)2(cod)4](+) (3(+)) was obtained as the tetrafluoroborate salt by reaction of 3 with 1 molar equiv of AgBF4, but the related complex 4(+) could not be isolated from the chemical oxidation of [Ir4(mu-PyS2)2(tfbb)4] (4) with AgBF4. Oxidation of 3 and 4 with 2 molar equiv of common silver salts resulted in the fragmentation of the complexes to give the diamagnetic triiridium cations [Ir3(mu-PyS2)2(diolefin)3](+). The molecular structure of [Ir3(mu-PyS2)2(cod)3]BF4, determined by X-ray diffraction methods, showed the three metal atoms within an angular arrangement. Both 2,6-pyridinedithiolate tridentate ligands bridge two metal-metal bonded d(7) centers in pseudo octahedral environments and one d(8) square-planar iridium center. An interpretation of the EPR spectra of the 63-electron mixed-valence paramagnetic tetranuclear complexes suggests that the unpaired electron is delocalized over two of the metal atoms in the complexes 1(+)-3(+).

Cleavage of the human respiratory syncytial virus fusion protein at two distinct sites is required for activation of membrane fusion

Preparations of purified full-length fusion (F) protein of human respiratory syncytial virus (HRSV) expressed in recombinant vaccinia-F infected cells, or of an anchorless mutant (F(TM(-))) lacking the C-terminal 50 amino acids secreted from vaccinia-F(TM(-))-infected cells contain a minor polypeptide that is an intermediate product of proteolytic processing of the F protein precursor F0. N-terminal sequencing of the intermediate demonstrated that it is generated by cleavage at a furin-motif, residues 106-109 of the F sequence. By contrast, the F1 N terminus derives from cleavage at residue 137 of F0 which is also C-terminal to a furin recognition site at residues 131-136. Site-directed mutagenesis indicates that processing of F0 protein involves independent cleavage at both sites. Both cleavages are required for the F protein to be active in membrane fusion as judged by syncytia formation, and they allow changes in F structure from cone- to lollipop-shaped spikes and the formation of rosettes by anchorless F.

Synthesis and insertion reactions of the cyclometalated palladium-alkyl complexes Pd(CH(2)CMe(2)-o-C(6)H(4))L(2). Observation of a pentacoordinated intermediate in the insertion of SO(2)

Palladacycles of the type 2, have been synthesized by treatment of the corresponding chloroalkylcomplexes Pd(CH(2)CMe(2)C(6)H(5))ClL(2) (L(2) = (PMe(3))(2), 2a, or 1,5-cyclooctadiene (cod), 2b) with suitable bases, or by simple ligand exchange reactions from the cyclooctadiene derivative 2b. The metallacycles 2 react with activated alkynes and with sulfur dioxide, giving rise to different insertion products.

Surgical and physical stress increases circulating blood dendritic cell counts independently of monocyte counts

Dendritic cells (DCs) are specialized antigen-presenting cells that have the unique ability to initiate a primary immune response. The effect of physiologic stress on circulating blood DCs has thus far not been studied. In this study, we applied a recently developed method of counting blood DCs to test the hypothesis that significant stress to the body such as surgery and exercise might induce measurable changes in the DC numbers, subsets, phenotype, and function. Twenty-six patients scheduled for elective laparoscopic cholecystectomy, 4 for elective hysterectomy, 56 controls, and 5 volunteers who underwent a stress exercise test were enrolled in the study. Absolute DC counts increased acutely (71.7% +/- 11% [SEM], P =.0001) in response to the stress of surgery and dropped below preoperative levels (-25% +/- 14% [SEM], P =.05) on days 2-3. The perioperative DC subset balance remained constant. Interestingly, DC counts changed independently of monocyte counts. Exercise also induced a rise in DC counts but coincidentally with monocyte counts. Surprisingly, no phenotypic or functional activation of DCs was seen in either stress situations in vivo. DCs are rapidly mobilized into the circulation in response to surgical and exercise stress, which may serve to prepare the host's immune defenses against trauma. The independent regulation of the DC and monocyte counts reinforces the distinction between these 2 cell populations.

Expression of the amino-terminal domain of platelet glycoprotein Ib alpha: exploitation of a calmodulin tag for determination of its functional activity

Platelet glycoprotein (GP) Ibalpha is a component of the GPIb-IX receptor complex, which is involved in multiple physiological and pathological processes, including platelet adhesion at sites of vascular injury, thrombin binding, Bernard-Soulier syndrome, platelet-type von Willebrand disease, and immune-mediated thrombocytopenias. The amino-terminal domain of approximately 300 residues of GPIbalpha mediates both normal biological function (by providing the sites for direct ligand interaction) and aberrant function (through amino acid substitutions). To investigate the molecular interactions mediated by this region of GPIbalpha, we have developed a recombinant baculovirus to facilitate its expression as a calmodulin fusion protein from insect cells. By employing the calmodulin tag, the fusion protein could be obtained at >90% purity after a single isolation step at yields of 8 mg/L of insect cell medium (purified fusion protein). The recombinant GPIbalpha fragment was shown to be posttranslationally sulfated and glycosylated, although its glycosylation differed from that of the equivalent GPIbalpha fragment isolated from human platelets. The differential glycosylation, however, did not affect the function of the recombinant GPIbalpha fragment in either von Willebrand factor (vWf) or thrombin binding as these were both found to be identical to those of the same-length GPIbalpha fragment derived from human platelets. The calmodulin tag was also exploited in the development of assays to measure directly vWf and thrombin binding, since it did not interfere with either, demonstrating the feasibility for the use of this soluble receptor fusion protein in detailed biophysical assays to investigate the molecular mode of binding of platelet glycoprotein Ibalpha to these ligands.

A synthetic malaria vaccine elicits a potent CD8(+) and CD4(+) T lymphocyte immune response in humans. Implications for vaccination strategies

We report the first synthetic peptide vaccine eliciting strong CD8(+) and CD4(+) T lymphocyte responses in humans. The vaccine, representing the C-terminal region of the circumsporozoite protein of Plasmodium falciparum (amino acids 282-383) was well tolerated and strong sporozoite-specific antibodies were elicited. In addition, robust lymphocyte proliferation responses were equally elicited with concomitant in vitro production of IFN-gamma, crucial in the elimination of the parasite. Most importantly, we also observed the development of CD8(+) T lymphocyte responses decisive in the immunity to malaria. The latter finding opens new, possibly safer, avenues for vaccination strategies when a CD8(+) T cell response is needed.

Platelet glycoprotein Ibalpha Kozak polymorphism is associated with an increased risk of ischemic stroke

Platelets are pivotal to the process of arterial thrombosis resulting in ischemic stroke. Occlusive thrombosis is initiated by the interaction of von Willebrand factor (vWf) and platelet glycoprotein (GP) Ibalpha. Three polymorphisms have been described in GP Ibalpha (Kozak T/C polymorphism, variable number of tandem repeats [VNTR], and the human platelet antigen 2a [HPA-2a] [Thr] or HPA-2b [Met] at position 145), each of which may enhance the vWf and GP Ibalpha interaction. This study investigated whether these polymorphisms are candidate genes for first-ever ischemic stroke. A hospital-based case-control study was conducted of 219 cases of first-ever ischemic stroke and 205 community controls randomly selected from the electoral roll and stratified by age, sex, and postal code. The subtypes of stroke were classified, the prevalence of conventional risk factors was recorded, and blood was collected to perform genotyping analysis for Kozak C or T alleles, VNTR, and HPA-2a/b. It was found that the Kozak T/C genotype was over-represented in the stroke group (32.2%) compared with controls (22.8%) (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.03-2.54; P <.03), and the association was still present even after adjusting for conventional risk factors. There was a trend in the increased prevalence of HPA-2a/b in stroke patients (15%) compared with controls (9.9%) (adjusted OR, 1.8; 95% CI, 0.94-3.4; P =.07). No associations were seen with the VNTR polymorphism or with any of the polymorphisms with stroke subtype. It was concluded that the Kozak T/C polymorphism, which is associated with an increase in platelet GP Ibalpha surface expression, is an independent risk factor for first-ever ischemic stroke.