Non-Equilibrium Fractionation Factors for D/H and 18O/16O During Oceanic Evaporation in the North-West Atlantic Region

Ocean isotopic evaporation models, such as the Craig-Gordon model, rely on the description of nonequilibrium fractionation factors that are, in general, poorly constrained. To date, only a few gradient-diffusion type measurements have been performed in ocean settings to test the validity of the commonly used parametrization of nonequilibrium isotopic fractionation during ocean evaporation. In this work, we present 6 months of water vapor isotopic observations collected from a meteorological tower located in the northwest Atlantic Ocean (Bermuda) with the objective of estimating nonequilibrium fractionation factors (k, ‰) for ocean evaporation and their wind speed dependency. The Keeling Plot method and Craig-Gordon model combination were sensitive enough to resolve nonequilibrium fractionation factors during evaporation resulting into mean values of k ₁₈ = 5.2 ± 0.6‰ and k ₂ = 4.3 ± 3.4‰. Furthermore, we evaluate the relationship between k and 10-m wind speed over the ocean. Such a relationship is expected from current evaporation theory and from laboratory experiments made in the 1970s, but observational evidence is lacking. We show that (a) in the observed wind speed range [0-10 m s^-1], the sensitivity of k to wind speed is small, in the order of -0.2‰ m^-1 s for k ₁₈, and (b) there is no empirical evidence for the presence of a discontinuity between smooth and rough wind speed regime during isotopic fractionation, as proposed in earlier studies. The water vapor d-excess variability predicted under the closure assumption using the k values estimated in this study is in agreement with observations over the Atlantic Ocean.

Atmosphere-Snow Exchange Explains Surface Snow Isotope Variability

The climate signal imprinted in the snow isotopic composition allows to infer past climate variability from ice core stable water isotope records. The concurrent evolution of vapor and surface snow isotopic composition between precipitation events indicates that post-depositional atmosphere-snow humidity exchange influences the snow and hence the ice core isotope signal. To date, however, this is not accounted for in paeleoclimate reconstructions from isotope records. Here we show that vapor-snow exchange explains 36% of the summertime day-to-day δ18O variability of the surface snow between precipitation events, and 53% of the δD variability. Through observations from the Greenland Ice Sheet and accompanying modeling we demonstrate that vapor-snow exchange introduces a warm bias on the summertime snow isotope value relevant for ice core records. In case of long-term variability in atmosphere-snow exchange the relevance for the ice core signal is also variable and thus paleoclimate reconstructions from isotope records should be revisited.

Yellow (Lens) Better: Bioelectrical and Biometrical Measures to Assess Arousing and Focusing Effects

Colours can induce several psychological effects, conditioning perceptions, cognitive/emotional states and human performances. In this exploratory study we investigated the effect of a yellow light exposure, obtained filtering the ambient light with coloured glasses, on the human's psychological functioning. In particular we wanted to assess if people are more able to focus when exposed to a yellow light. We recorded EEG, SC, HR and gaze-related data from 16 subjects (50% split in experimental and control group) during the execution of a reactivity test (the Hazard Perception Test, HPT). Compared with the control group, the experimental group showed increases in concentration, focus, visual attention and arousal, as measured by increases of first fixation duration and Beta over-Alpha ratio (BAR) as well as by decreases of distraction, workload, and number of gaze revisits.

Expansion of Health Networks as a Building Block of a Functioning Health Landscape

A health network is made up of institutions and organizations, resources, and people whose main purpose is to promote and improve health. The health care system in Germany is self-administering and is managed by multiple institutions and stakeholders which entails different organizations involved in the running of the health care as well as the structure of the health care system. The health care system is composed of three main areas: 1) outpatient care services, 2) inpatient care, 3) rehabilitation institutions. Some of the organizations and institutions that are mandated to run the health system include associations and representatives of different professions and service providers, regulatory bodies, health insurance companies, the Federal Ministry of Health, self-help groups, and patient-centered organizations. The German health care system is made up of four main principles: 1) compulsory insurance, 2) the principle of solidarity, 3) financing through insurance premiums, 4) selfgovernance. The goal of health care networks is to improve the overall performance of the health care systems concerning: 1) economic efficiency, 2) quality of health care services, 3) medical innovation, 4) as well as patient satisfaction.

Looking through blue glasses: bioelectrical measures to assess the awakening after a calm situation

Colors can elicit cognitive and emotional states. In particular, blue colour is associated to "refresh" and "restart" effects and is suggested to enhance a wake-up after a calm situation. In this exploratory study, these claims are investigated using Electroencephalographic (EEG), Skin Conductance (SC) and pupil diameter data. The results confirmed the "wake-up effect" for subjects wearing the lenses, as measured by Global Field Power (GFP) in Theta Band, Skin Conductance Response (SCR) and pupil diameter data.

Measurement and implications of Saturn’s gravity field and ring mass

The interior structure of Saturn, the depth of its winds, and the mass and age of its rings constrain its formation and evolution. In the final phase of the Cassini mission, the spacecraft dived between the planet and its innermost ring, at altitudes of 2600 to 3900 kilometers above the cloud tops. During six of these crossings, a radio link with Earth was monitored to determine the gravitational field of the planet and the mass of its rings. We find that Saturn’s gravity deviates from theoretical expectations and requires differential rotation of the atmosphere extending to a depth of at least 9000 kilometers. The total mass of the rings is (1.54 ± 0.49) × 1019 kilograms (0.41 ± 0.13 times that of the moon Mimas), indicating that the rings may have formed 107 to 108 years ago.

Association of dietary patterns with five-year degree and progression of coronary artery calcification in the Heinz Nixdorf Recall study

BACKGROUND AND AIMS

As a modifiable lifestyle factor, diet is hypothesized to play an important role in the progression of atherosclerosis. The aim of this study was to explore associations of comprehensive dietary patterns derived by cluster analysis with degree and progression of coronary artery calcification (CAC) over five years of follow-up.

METHODS AND RESULTS

In the population-based Heinz Nixdorf Recall study, 3718 participants (45-75 years; 47.6% men) without coronary heart disease completed a food frequency questionnaire at baseline. Five distinct dietary patterns were identified using cluster analysis: "Health-conscious", "Traditional German/Less alcohol", "Mediterranean-like", "Western" and "Animal fat/Alcohol" (used as reference). CAC was measured using electron-beam computed tomography at baseline and five years later. CAC after five years was predicted based on sex- and age-specific baseline percentiles. After comparing observed and predicted CAC Scores, CAC progression was classified as slow, expected, or rapid. Compared to "Animal fat/Alcohol" diet, a "Mediterranean-like" diet was associated with a relative risk (RR) for a rapid CAC progression in both sexes (men: 0.61; 95%-confidence interval [95%-CI]: 0.41; 0.90; women: 0.59; 95%-CI: 0.45; 0.78). Furthermore, reduced RRs were observed in women with a "Health-conscious" and a "Traditional German/Less alcohol" diet (0.63; 95%-CI: 0.47; 0.84, respectively 0.69; 95%-CI: 0.52; 0.90). No association was observed for a "Western" diet for both sexes. Similar results were revealed for degree of CAC.

CONCLUSION

The study results support the hypothesis that a "Mediterranean-like" diet is associated with a lower CAC-progression and lower degree of CAC in men and women.

Caliber of the common bile duct: effect of cholecystectomy and other factors in a ultrasonographic study of 8534 patients

OBJECTIVE

The objective of the present study was to analyze the effects of different factors impacting the caliber of the common bile duct (CBD) and a comparison of maximum extrahepatic bile duct caliber in patients with and without a history of cholecystectomy.

MATERIAL AND METHODS

A retrospective data analysis was undertaken of 8534 patients (4480 females; 4054 males; average age: 59.2±18.0 years) with sonographic documentation of bile duct caliber. Maximum intra- and extrahepatic bile duct diameters were studied. The normal maximum diameter of the extrahepatic bile duct was defined as 7 mm. In patients who had undergone prior cholecystectomy, a maximum bile duct diameter<10 mm was considered normal.

RESULTS

The average maximum diameter of the CBD amounted to 5.3±3.0 mm for the overall collective. In patients who had undergone prior cholecystectomy, maximum CBD diameters in the normal range (<7 mm) were documented in 55%, while larger diameters (>7 mm) were observed in 45%. In the collective of patients without prior cholecystectomy, CBD diameters in the normal range (<7 mm) were found in 81%, with larger diameters observed in only 18.4% of patients. In both subgroups, there was a significant association between age and bile duct diameter (for those with prior cholecystectomy, p=0.0003; without prior cholecystectomy, p<0.0001). No statistically significant influence on CBD diameter was observed for either prior cholecystectomy (p=0.2116) or time interval since cholecystectomy (p=0.3537). Females, both with and without a history of prior cholecystectomy, showed a 1.4-1.5-fold higher risk of exhibiting a CBD diameter>7 mm (for those with prior cholecystectomy, p=0.0485; without prior cholecystectomy, p<0.001).

CONCLUSIONS

Our data show a positive correlation between age and CBD diameter. There was no statistically significant relationship between CBD diameter and prior cholecystectomy, postoperative interval and BMI.

A common atopy-associated variant in the Th2 cytokine locus control region impacts transcriptional regulation and alters SMAD3 and SP1 binding

BACKGROUND

Type 2 immune responses directed by Th2 cells and characterized by the signature cytokines IL4, IL5, and IL13 play major pathogenic roles in atopic diseases. Single nucleotide polymorphisms in the human Th2 cytokine locus in particular in a locus control region within the DNA repair gene RAD50, containing several RAD50 DNase1-hypersensitive sites (RHS), have been robustly associated with atopic traits in genome-wide association studies (GWAS). Functional variants in IL13 have been intensely studied, whereas no causative variants for the IL13-independent RAD50 signal have been identified yet. This study aimed to characterize the functional impact of the atopy-associated polymorphism rs2240032 located in the human RHS7 on cis-regulatory activity and differential binding of transcription factors.

METHODS

Differential transcription factor binding was analyzed by electrophoretic mobility shift assays (EMSAs) with Jurkat T-cell nuclear extracts. Identification of differentially binding factors was performed using mass spectrometry (LC-MS/MS). Reporter vector constructs carrying either the major or minor allele of rs2240032 were tested for regulating transcriptional activity in Jurkat and HeLa cells.

RESULTS

The variant rs2240032 impacts transcriptional activity and allele-specific binding of SMAD3, SP1, and additional putative protein complex partners. We further demonstrate that rs2240032 is located in an RHS7 subunit which itself encompasses repressor activity and might be important for the fine-tuning of transcription regulation within this region.

CONCLUSION

The human RHS7 critically contributes to the regulation of gene transcription, and the common atopy-associated polymorphism rs2240032 impacts transcriptional activity and transcription factor binding.

Bubble production mechanism in a microfluidic foam generator

We present the design and characterization of a microfluidic bubble generator that has the potential of producing monodisperse bubbles in 256 production channels that can operate in parallel. For a single production channel we demonstrate a production rate of up to 4 kHz with a coefficient of variation of less than 1%. We observe a two-stage bubble production mechanism: initially the gas spreads onto a shallow terrace, and then overflows into a larger foam collection channel; pinning of the liquid-gas meniscus is observed at the terrace edge, the result being an asymmetric pinch-off. A semiempirical physical model predicts the scaling of bubble size with fluid viscosity and gas pressure from measurements of the pinned meniscus width.

Expression of chitinase-like proteins in inflamed tissues of Sjögren’s Syndrome (SS) patients (135.6)

SS represents a chronic autoimmune disease of salivary and lacrimal glands that may be accompanied by multi-organ systemic manifestations. Among the locally involved innate immune defense populations are macrophages, which have been linked to IL-12 and IL-23 that moderate T lymphocyte lineage commitment. To further an understanding of the immunopathologic sequelae associated with SS and to define therapeutic targets, we performed microarray analysis of target tissues from SS patients with severe histopathologic lesions compared to those with sicca symptomatology but negative minor salivary gland biopsy. We identified the expression of multiple genes, including members of the mammalian chitinase family, not previously associated with exocrinopathies, among the most highly expressed SS genes as compared to diseased, but non-SS tissues. Both chitinase-3-like-1 (CHI3L1/YKL-40) and chitinase 1 (CHIT1), highly conserved members of the mammalian chitinase-like glycoprotein family, one with and one lacking enzymatic activity, were evident at the transcriptome levels, as well as detected as glycoproteins within inflamed salivary glands. Monocyte to macrophage differentiation is accompanied by an increase in chitinase expression, which can be augmented by cytokine exposure. Since the elevated expression of these molecules corresponded with more advanced disease in SS patients, these observations suggested a potential immunopathologic involvement.

Regulating immunity to malaria

The optimal outcome of a malaria infection is that parasitized cells are killed and degraded without inducing significant pathology. Since much of the pathology of malaria infection can be immune-mediated, this implies that immune responses have to be carefully regulated. The mechanisms by which anti-malarial immune responses are believed to be regulated were discussed at the recent Malaria Immunology Workshop (Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA; February 2005). Potential regulatory mechanisms include regulatory T cells, which have been shown to significantly modify cellular immune responses to various protozoan infections, including leishmania and malaria; neutralising antibodies to pro-inflammatory malarial toxins such as glycosylphosphatidylinositol and haemozoin; and self-regulating networks of effector molecules. Innate and adaptive immune responses are further moderated by the broader immunological environment, which is influenced by both the genetic background of the host and by co-infection with other pathogens. A detailed understanding of the interplay between these different immunoregulatory processes may facilitate the rationale design of vaccines and novel therapeutics.

Look, learn, and be satisfied: video playback as a learning strategy to improve clinical skills performance

The study investigated the viability of video playback as a means to maintain and enhance nursing skills in today's healthcare environment. The purpose was to determine if video playback would improve performance of psychomotor clinical skills and increase participant satisfaction with the leaning process. A two-group sample of registered and student nurses participated in the study. Each participant performed a nursing procedure. Two nursing procedures were used, one for each group. Each nursing procedure was recorded on videotape and played back to the participant who then repeated the procedure and completed a satisfaction assessment questionnaire. Results showed improved performance and learner satisfaction.

The receptor tyrosine phosphatase CRYPalpha affects growth cone morphology

During development of the nervous system receptor tyrosine kinases and receptor protein tyrosine phosphatases act in a coordinate way during axon growth and guidance. In the developing avian retinotectal system, many different receptor protein tyrosine phosphatases are expressed. Most of them have unknown functions. Retinal ganglion cells express at least three different members of this receptor family on their axons and growth cones: CRYPalpha, CRYP-2 and PTPmu. CRYPalpha interacts heterophilically with at least two different ligands found in the basal membranes of the retina and the optic tectum. To analyze the role of the CRYPalpha-ligand interaction, retinal ganglion cell axons were grown on retinal basal membranes (inner limiting membrane) and the receptor-ligand interaction was blocked from both the receptor side (by receptor specific antibodies) and from the ligand side by using a receptor-alkaline phosphatase fusion protein. Both of these treatments reduced average retinal axon length and induced a dramatic change in morphology of retinal ganglion cell growth cones on basal membranes, but not on other substrates like laminin, N-cadherin, matrigel- and detergent-treated basal membranes. These results suggest that CRYPalpha and its ligand act as growth-promoting molecules during intraretinal axon growth.

Revised fine splitting of excitons in diamond

We study low-strain synthetic high pressure, high temperature diamonds by cathodoluminescence and observe novel fine structure in the free exciton and the boron-bound exciton emission. The basic spectral structure is a doublet with DeltaE approximately 11 meV common to both exciton spectra. This resolves the previously found inequivalence of free exciton ( approximately 7 meV) and bound exciton ( approximately 12 meV) fine splitting. It is argued that for a spin-orbit interaction Delta(0) much smaller than the excitonic binding ( E(X) approximately 80 meV) and the excitonic localization ( E(loc) approximately 51 meV) at the boron acceptor, the orbital momentum and the spin of the particles constituting the electron-hole pair are recoupled to form spin singlet and triplet exciton states as the elementary excitations.

Apoptosis induction by a novel anti-prostate cancer compound, BMD188 (a fatty acid-containing hydroxamic acid), requires the mitochondrial respiratory chain

We recently developed a class of novel anti-prostate cancer compounds, cyclic hydroxamates that elicit a potent apoptotic response in many tumor cells cultured in vitro (D.G. Tang et al., Biochem. Biophys. Res. Commun., 242: 380-384, 1998). The lead compound, termed BMD188, induces programmed cell death in a variety of prostate cancer cells in vitro as well as in vivo (L. Li et al., Anticancer Res., 19: 51-70, 1999). BMD188 kills androgen-independent prostate cancer cells as well as prostate cancer cells with a multidrug-resistance phenotype. The apoptotic effect of BMD188 in prostate cancer cells does not depend on cell cycle, p53 status, or its purported target, arachidonate 12-lipoxygenase, but does require caspase activation and seems to involve mitochondria. To synthesize more specific and effective anti-prostate cancer hydroxamic acid compounds, it is important to understand their mechanism(s) of action. In the present study, we studied the role of mitochondrial respiratory chain (MRC) in BMD188-induced apoptosis in androgen-independent prostate cancer PC3 cells and compared its effect with that of staurosporine (STS), a widely used apoptosis inducer. Several lines of evidence indicate that BMD188-induced cell death depends on MRC: (a) the death could be significantly inhibited by several complex-specific respiration inhibitors; (b) respiration-deficient rho0 cells were more resistant than wild-type parent cells to apoptosis induction by BMD188; and (c) BMD188 induced a rapid increase in reactive oxygen species in mitochondria, an up-regulation of cytochrome c oxidase subunits, a biphasic alteration (i.e., an early hyperpolarization, followed by later hypopolarization) in the mitochondrial membrane potential (delta psi(m)), dramatic changes in mitochondrial morphology and distribution prior to caspase activation, and an abnormal proliferation of mitochondria at the ultrastructural level. By contrast, STS-induced PC3 apoptosis seemed not to depend on MRC. Taken together, the data suggest that the MRC represents a functional target for anti-prostate cancer hydroxamates.

The significance of rota representation in the design of rotas

Shift scheduling is based on some representation of shift schedules. The number of different representations currently used is high, and one might expect small practical differences between these representations. However, an analysis of several prominent representations revealed strong differences regarding possible outcomes of the scheduling process and the effort needed for their assessment. Limitations of some representations do not only concern specific rota design issues, such as different staffing levels or different workhours, but also rather simple and straightforward rotas. Furthermore, there is no single representation that is strictly and unequivocally better than the others. Most representations simplify the development of some rotas, while they make it very difficult or even impossible to develop others. Therefore, both designers and the computer systems used for design should use and support several representations and therefore allow smooth transitions between them. In addition knowledge about rota construction techniques should be maintained, as it may ease assessment dramatically.

A technique to take leave into account in shift-rota design

Sick leave, vacations, and the like lead to substantial leave factors. Rota design techniques for covering leave are not always feasible. A small company was helped to develop a new rota. The main requirements were an ergonomically better rota, less overtime caused by leave, and a rota that lets employees take their vacation during the summer. The internal evaluation was unanimously positive after 1 year. A prospective leave coverage was used, with different workhours during summer and spring and with a mixture of shift work and flexible day work. Later the rota was further refined, and broader qualifications of the workers made a much simpler rota possible. The experiences of this study indicate that problems with leave can be reduced if expected variations in leave are considered in the rota design by including variations in workhours. A further promising strategy is to mix shift work with other types of work when time is not a critical factor.

[Cognition and emotion in the evaluation of accidents: modelling and empirical studies]

Lay people's evaluation of environmental risks is often based on mass media descriptions of single disastrous events. This article analyzes the cognitive and emotional reactions towards those reports. We assume that characteristic features of the events determine the cognitive evaluation and the rise of the emotions anger and sadness. An intuitive, spontaneous, and schema-based evaluation process is postulated that entails a coherent perception and appraisal of an event. The theoretical assumptions are formally specified and implemented in the computer model ITERA (Intuitive Thinking in Environmental Risk Appraisal). In three experimental studies, we presented manipulated descriptions about negative environmental events. The effects of three experimental variables (knowledge about the riskiness of an action, higher goal of the actor, voluntarity of the actor) were compared with the model's predictions. For anger we found a good correspondence between the empirical results and the model's data. The predicted coherence effects of the cognitive appraisal were confirmed to a great extent. Results for sadness did not conform with model predictions.

Cervical human immunodeficiency virus type 1 shedding is associated with genital beta-chemokine secretion

Forty human immunodeficiency virus type 1 (HIV-1)-infected women participated in a cross-sectional study of possible correlations between chemokine receptor (CCR5 and/or CCR2B) genotype, HIV-1 RNA and DNA load, and beta-chemokine levels (RANTES, MIP-1alpha, MIP-1beta) in blood and cervix. HIV-1 nucleic acid and beta-chemokines were found in all patient blood samples and in more than half of the cervical samples regardless of CCR5 or CCR2B genotype. High beta-chemokine concentrations were in general associated with high virus loads in blood and cervix. In the blood, the proviral DNA load was significantly correlated with the MIP-1alpha concentration, whereas the DNA load in cervix was significantly associated with the MIP-1beta concentration. The cervical viral RNA load was significantly associated with levels of all three chemokines. Thus, when HIV-1 shedding was highest in the genital tract, it was associated with other combinations of beta-chemokines than virus load in blood, suggesting that local immune reactions strongly influence virus load in the cervical compartment.

Distinct determinants of human immunodeficiency virus type 1 RNA and DNA loads in vaginal and cervical secretions

The relationship between human immunodeficiency virus type 1 (HIV-1) viral RNA and proviral DNA load in vagina and cervix and that found in the plasma and peripheral blood mononuclear cells (PBMC) was investigated in 28 HIV-1-infected women. Of the patients, 64% had > or = 1 HIV-1 RNA-positive genital sample, while 71% had > or = 1 DNA-positive sample. The higher the cervical HIV load, the more widespread was the virus in the genital tract. A strong correlation was found between viral RNA load in plasma and the genital tract, whereas the association between proviral DNA load in PBMC and the genital tract was less evident. Cervical HIV-1 DNA correlated with a viral RNA load > or = 50,000 copies/mL. Cervical HIV-1 RNA levels ranged from 10% to 100% of the plasma levels. Thus, a continuous transmission risk from untraumatized genital epithelium exists in the majority of HIV-1-infected women at all stages of infection.

Relationship Between Tolerance/Intolerance of Ambiguity and Perceived Environmental Uncertainty in Hospitals

1 Many variables may contribute to a nurse's perceptions when working in a changing health care environment, especially in the field of psychiatry. 2 While this study did not find a relationship between tolerance for ambiguity and perceived environmental uncertainty in hospitals, age and educational background appear to be variable, which may warrant further study as ultimately impacting nursing. 3 Research which explores those personality variables which underlie perception would assist nurse administrators in designing interventions, opening new lines of communication, and increasing sensitivity to individual nurse's need in these changing times.

Thermoalkalophilic lipase of Bacillus thermocatenulatus large-scale production, purification and properties: aggregation behaviour and its effect on activity

Escherichia coli BL321 was transformed with the expression plasmid pCYTEXP1 carrying the BTL2 gene from Bacillus thermocatenulatus under the control of the strong temperature-inducible lambda pL promoter and was cultivated in a 100 1 bioreactor. The mature lipase was produced in large quantities (54,000 U g-1 wet cells) and further purified to homogeneity by a two-step purification protocol (hydrophobic chromatography and gel filtration chromatography). The pure enzyme was characterized and its physicochemical properties compared to those of the BTL2 lipase which had previously been weakly expressed in E. coli under the control of its native promoter on pUC18, yielding 600 U g-1 wet cells. The specific activity of the overexpressed enzyme was approx. 5-fold higher than that of the weakly expressed enzyme. The two proteins showed the same pI and N-terminal sequence and had very similar thermostability, pH stability, optimum pH and temperature activity, and substrate specificity. Both enzymes were extremely stable in the presence of several organic solvents and detergents. With trioleylglycerol as a substrate, the overexpressed lipase cleaves each of the three ester bonds. The purified BTL2 lipase shows a strong tendency to aggregate. Direct evidence for changes in the aggregation state was obtained by gel filtration chromatography. The effect of aggregation on lipase activity was strongly dependent on both substrate and temperature during the assay. Under certain conditions, a direct relationship was found between the molecular mass of the lipase aggregates and the increase in activity upon the addition of 1% (w/v) sodium cholate.

Clearance of postprandial lipoproteins in normolipemics: role of the apolipoprotein E phenotype

The hepatic clearance of triglyceride-rich lipoproteins is mediated via apolipoprotein (apo) E which occurs in three common isoforms, apoE2, apoE3 and apoE4. To study the importance of the apoE isoforms on the response curves of different triglyceride-rich lipoproteins and the effect of chylomicron remnants on the composition of HDL, 37 normolipemics were investigated after a standardized fatty meal (8 apoE2/E2, 8 apoE2/E3, 8 apoE3/E3, 7 apoE3/E4 and 6 apoE4/E4). These individuals were matched for age, body mass index, fasting triglycerides, HDL-cholesterol, and apoA-I. A delayed chylomicron remnant clearance was observed only in apoE2 homozygotes, and this delay was neither correlated with fasting lip ds nor with peak lipoprotein concentrations. In apoE2/E3 heterozygotes, in contrast, the defective isoform E2 appears to be compensated for by the normal apoE isoform E3. In non-apo-E2/E2 individuals, the chylomicron remnant response was highly correlated with the magnitude of chylomicron and VLDL responses, with fasting triglycerides, and with the triglycerides enrichment and cholesterol depletion of HDL. These correlations were not observed in apoE2/E2. From these results we conclude that the chylomicron remnant response curve is an indicator of the extent of postprandial lipemia in non-apoE2/E2 individuals only.

Granulocyte-macrophage colony-stimulating factor induces human melanoma-cell migration

Tumor metastasis is the primary cause of death for cancer patients. The metastatic cascade requires successful tumor cell invasion into and through vascular and parenchymal barriers. We have shown that autocrine motility factor (AMF, autotaxin) and the insulin-like growth factors (IGFs) induce tumor-cell migration. Since granulocyte-macrophage colony-stimulating factor (GM-CSF) has been shown to prime neutrophils for chemotaxis, we have therefore studied the influence of GM-CSF upon tumor cells and report that GM-CSF stimulates migration of these cells in a dose-dependent fashion. The ED50 for A2058 human melanoma cell line chemotaxis to GM-CSF is approx. 60 pM. The motile response to GM-CSF was additive to that of IGF-I and AMF, both of which are potent attractants for tumor cells. Pre-treatment of cells for 2 hr with non-toxic concentrations of pertussis toxin (PT) or amiloride resulted in a 50% inhibition of chemotaxis to GM-CSF. Therefore, GM-CSF, through PT- and amiloride-sensitive signal pathways, is a potent attractant for melanoma cells, the response to which is additive to that of other attractants. The presence of the GM-CSF receptor in A2058 melanoma cells was indicated by Northern-blot analysis which identified message transcripts of 2.1 and 3.0 kb. These data emphasize the versatility of the melanoma cell migration response to an array of cytokines, including GM-CSF.

Acquired immunodeficiency syndrome-associated lymphomas: clinical, pathologic, immunologic, and viral characteristics of 111 cases

The incidence of lymphomas in individuals infected with the human immunodeficiency virus has increased progressively since the beginning of the acquired immunodeficiency syndrome (AIDS) epidemic. The present series includes 111 patients, all diagnosed and studied at one hospital in New York City. There were 108 men and three women; the average age was 39 years and male homosexuality was the predominant risk factor. The materials examined originated from 138 surgical specimens and 24 autopsies. There were 11 cases of Hodgkin's lymphoma and 100 cases of non-Hodgkin's lymphomas (NHL), a proportion strongly skewed in favor of the latter. Hodgkin's lymphoma in AIDS patients was characterized by advanced clinical stage, high histologic grade, and frequent bone marrow involvement. Non-Hodgkin's lymphoma in AIDS patients, in contrast to the general population, originated predominantly in extranodal locations (61 cases) versus locations in which the lymph nodes were the site of the primary tumors (39 cases). In the digestive tract, the unusual oral and anal primary locations were often noted and were possibly related to specific risk factors. There were 15 cases of NHL of the central nervous system, an incidence 14 times greater than that recorded in the general population. The majority of NHLs were of high histologic grade, Burkitt's and large cell immunoblastic, representing most of the cerebral and gastrointestinal tumors. All NHLs were of B-cell immunophenotype. Lymphadenopathies with the histologic features of human immunodeficiency virus infection, particularly of the late stage (type C), often preceded NHL. Probing for Epstein-Barr virus genome was more frequently positive in Hodgkin's lymphoma than in NHL. Immunologic evaluations showed severely depressed T cell counts and CD4 to CD8 cell ratios as well as markedly increased levels of antilymphocyte antibodies. Reflecting the background of profound immune deficiency, the AIDS-associated lymphomas were characterized by high aggressiveness, early tendency to generalization, frequent post-treatment relapse, and short periods of survival.

Immunologic parameters of response in patients with rheumatoid arthritis treated with cyclosporin A

Thirty-one patients with seropositive rheumatoid arthritis treated with cyclosporin A (CsA) were evaluated for immune function prior to, during, and after 1 year of therapy. Patients whose pretreatment peripheral blood mononuclear cells were hypoproliferative in vitro to soluble recall antigens responded better clinically to CsA treatment than did the other patients. During therapy, proliferative responses became normal and remained so until 1-2 months after CsA was discontinued. At that time, the lymphocyte proliferation defect reappeared. In addition, patients who responded clinically to CsA had a higher percentage of Leu-7+ natural killer cells in their peripheral blood prior to therapy. All patients exhibited greater frequencies of cells that expressed interleukin-2 receptors, which decreased with CsA treatment. The clinical response to CsA appears to be associated with distinct immunologic parameters in rheumatoid arthritis.

TGF-beta regulates production of growth factors and TGF-beta by human peripheral blood monocytes

Transforming growth factor beta 1 (TGF-beta 1) and its closely related homologue, TGF-beta 2, rapidly induce growth factor gene expression by freshly isolated human peripheral blood monocytes. Within 3 h of exposure to TGF-beta, mRNA species specific for interleukin-1 (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), platelet-derived growth factor (PDGF), and basic fibroblast growth factor (bFGF) were observed. By 14-18 h, cytokine bioactivity and protein were detected in the culture supernatants. Furthermore, not only TGF-beta 1, but also TGF-beta 2 mRNA are expressed constitutively in unstimulated monocytes. However, in response to exogenous TGF-beta (beta 1 or beta 2), only TGF-beta 1 gene expression is upregulated, and the expression of TGF-beta 2 mRNA is unchanged. This selective autoinduction of TGF-beta 1 appears to be controlled at both transcriptional and post-transcriptional levels. These paracrine and autocrine activities of TGF-beta suggest potential mechanisms through which an inflammatory response can be initiated and amplified. In addition, the TGF-beta enhancement of growth factor generation may promote fibrosis and angiogenesis relevant to physiological tissue repair as well as pathological fibrotic sequelae.

Proteolysis of human C-reactive protein produces peptides with potent immunomodulating activity

We have studied the ability of human C-reactive protein to modulate the immune response in vitro. Whereas native C-reactive protein did not induce phagocytic leukocytes to chemotax or to produce superoxide, treatment of purified C-reactive protein with human neutrophil-derived acid proteases produced substances with potent effects on leukocyte function. Close examination of the primary structure of human C-reactive protein revealed three regions evenly distributed throughout the protein each of which contain peptide sequences closely resembling the amino acid sequence of the immunomodulator peptide tuftsin, Thr-Lys-Pro-Arg. We have synthesized the three peptides which include Thr-Lys-Pro-Leu ([Leu4]tuftsin), Gly-Lys-Pro-Arg ([Gly1]tuftsin), and Thr-Lys-Pro-Gln ([Gln4]tuftsin) and assayed them for biological activity. The three synthetic peptides were found to stimulate phagocytic leukocytes to chemotax, produce superoxide, and induce mononuclear cells to produce interleukin 1 in vitro at concentrations similar to those concentrations required for tuftsin to induce these phenomena. These results support a potentially important role for C-reactive protein as a possible immunomodulator during inflammation.

Characterization of monoclonal antibodies specific for the pre-S2 region of the hepatitis B virus envelope protein

Monoclonal antibodies (McAb) specific for the pre-S region of the hepatitis B virus (HBV) envelope protein were prepared using HBV particles of hepatitis B surface antigens (HBsAg) as immunogens. The antibodies reacted in Western blot analyses and in ELISA with pre-S2 sequences of the HBV envelope protein. Pepsin or protease V8 treatment of the antigen abolished reactivity. The fine specificity of one of the McAb (F376) was established by immunoassays using synthetic peptides and a pre-S2-beta-galactosidase fusion protein expressed in E. coli. The shortest peptide recognized by F376 is demarcated by residues pre-S(132) at the N-terminal and pre-S(140)-pre-S(145) at the C-terminal. The corresponding amino acid sequence (for HBV subtype adw2) is: QDPRVRGLY(LPAGG). Additional amino acid residues at the N-terminal, and possibly at the C-terminal ends contribute to the binding of McAb, probably due to conformational influences. The McAb was applied to immunoassays of pre-S2 sequences in purified HBsAg and in human sera containing HBsAg.