Human endogenous peptide p33 inhibits detrimental effects of LL-37 on osteoblast viability.

BACKGROUND AND OBJECTIVE: High levels of the antimicrobial peptide, LL-37, are detected in gingival crevicular fluid from patients with chronic periodontitis. LL-37 not only shows antimicrobial activity but also affects host-cell viability. The objective of the present study was to identify endogenous mechanisms that antagonize the detrimental effects of LL-37 on osteoblast viability, focusing on the human peptide p33 expressed on the surface of various cell types. MATERIAL AND METHODS: Human osteoblast-like MG63 cells and human hFOB1.19 osteoblasts were treated with or without LL-37 in the presence or absence of p33. Recombinant human p33 was expressed in an Escherichia coli expression system. Lactate dehydrogenase (LDH) was assessed using an enzymatic spectrophotometric assay. DNA synthesis was determined by measuring [(3) H]-thymidine incorporation. Cell number was assessed by counting cells in a Bürker chamber. Intracellular Ca(2+) was monitored by recording Fluo 4-AM fluorescence using a laser scanning confocal microscope. Cellular expression of p33 was determined by western blotting. RESULTS: LL-37 caused a concentration-dependent release of LDH from human osteoblasts, showing a half-maximal response value (EC50 ) of 4 µm and a rapid and sustained rise in the intracellular Ca(2+) concentration of osteoblasts, suggesting that LL-37 forms pores in the cell membrane. p33 (10 µm) inhibited the LL-37-induced LDH release and LL-37-evoked rise in intracellular Ca(2+) concentration, suggesting that p33 prevents LL-37-induced permeabilization of the cell membrane. Moreover, p33 blocked LL-37-induced attenuation of osteoblast numbers. Also, mucin antagonized, at concentrations representative for nonstimulated whole saliva, LL-37-evoked LDH release, whilst cationic endogenous polyamines had no impact on LL-37-induced LDH release from osteoblasts. CONCLUSIONS: The endogenous peptide p33 prevents LL-37-induced reduction of human osteoblast viability. Importantly, this mechanism may protect the osteoblasts from LL-37-induced cell damage in patients suffering from chronic periodontitis associated with high levels of LL-37 locally.

1α,25-dihydroxyvitamin D3 promotes osteogenic activity and downregulates proinflammatory cytokine expression in human periodontal ligament cells.

BACKGROUND AND OBJECTIVE: The aim of this study was to assess the impact of 1α,25-dihydroxyvitamin D3 (vitamin D3) on osteogenic and inflammatory properties of human periodontal ligament (PDL) cells and investigate underlying mechanisms. MATERIAL AND METHODS: Human PDL cells, obtained from four subjects, were stimulated with vitamin D3 for 4-48 h. The bone markers osteopontin and osteocalcin and proinflammatory cytokine/chemokine expression was determined by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Cytokine and chemokine expression was determined after stimulation with the inflammation promoter lipopolysaccharide (LPS) in the presence or absence of vitamin D3. Alkaline phosphatase activity was assessed using p-nitrophenylphosphate substrate. RESULTS: Treatment with 30 ng/mL of vitamin D3, corresponding to an optimal plasma concentration of vitamin D, for 24 h had no effect on PDL cell number and morphology but increased PDL cell osteopontin and osteocalcin mRNA expression by about 70 and 40%, respectively, and, moreover, treatment with vitamin D3 for 48 h enhanced PDL cell alkaline phosphatase activity by about two times showing that vitamin D3 exerts pro-osteogenic effects in human PDL cells. Stimulation with LPS (1 µg/mL) for 4 h increased PDL cell interleukin (IL)-6 cytokine and chemokine ligand 1 (CXCL1) chemokine mRNA expression several fold. The LPS-induced increase in IL-6 and CXCL1 transcripts was attenuated by vitamin D3 (30 ng/mL). Treatment with vitamin D3 (3-300 ng/mL) for 24 h reduced the LPS-evoked increase in PDL cell IL-6 protein by about 50%. Vitamin D3 (30 ng/mL) had no effect on LPS-induced IL-1ß and MCP-1 mRNA expression. CONCLUSIONS: Vitamin D3 promotes osteogenic differentiation but also downregulates inflammation promoter-induced IL-6 cytokine and CXCL1 chemokine expression in human PDL cells, suggesting that vitamin D3 both stimulates bone regeneration and antagonizes inflammation in human periodontal tissue.

Platelet count and function in paediatric cardiac surgery: a prospective observational study.

BACKGROUND: Platelet deficiency, impaired platelet function, or both increase the risk of bleeding complications. We assessed platelet count and function during and after paediatric cardiac surgery. Secondary aims included the effect of modified ultrafiltration, identification of factors associated with platelet dysfunction, and to assess associations between platelet function and transfusion requirements. METHODS: Fifty-seven patients were included in a prospective observational study. Platelet count and platelet function (multiple-electrode impedance aggregometry) were analysed before and during cardiopulmonary bypass (CPB), after modified ultrafiltration, on arrival at the intensive care unit, and on the first postoperative day. Intraoperative transfusions of blood products were registered. RESULTS: Both platelet count and platelet aggregation were markedly reduced during surgery with the greatest reduction at the end of CPB. On postoperative day 1, platelet count was still reduced by 50%, while platelet aggregation had returned to-or above-preoperative levels. There were only moderate correlations between platelet count and platelet aggregation. Modified ultrafiltration had no significant influence on platelet count or aggregation. Young age, low weight, and long operation time were associated with poor platelet aggregation during surgery, while young age, low weight, high preoperative haemoglobin levels, and low preoperative platelet count were associated with poor aggregation after operation. Patients with impaired platelet function during CPB had markedly increased intraoperative transfusion requirements. CONCLUSIONS: Platelet count and platelet aggregation are markedly reduced during and immediately after paediatric cardiac surgery, especially in neonates. The recovery in aggregation is faster than that in platelet count. Intraoperative platelet dysfunction is associated with increased transfusion requirements.

Work health determinants in employees without sickness absence.

BACKGROUND: Working ability is known to be related to good physical condition, clear work tasks, positive feedback and other occupational, organizational and psychosocial factors. In Sweden, high levels of sickness absence are due to stress-related disorders and musculoskeletal pain. AIMS: To identify work health characteristics in a working population with a large variety of professional skills and occupational tasks. METHODS: Employers' data on occupation, sickness absence, age and gender in a working population of 11 occupational groups and questionnaire responses regarding work-organization, environment, work stress, pain, health, and socio-demographic factors were collected. Employees with no history of sick-leave were compared with those with a history of sick-leave (1-182 days, mean 25 days). RESULTS: Of 2641 employees, 1961 participated. Those with no history of sick-leave reported less work-related pain, work-related stress, sleep disturbances, worry about their health, 'sick-presenteeism', monotonous work, bent and twisted working positions and exposure to disturbing noise than those with a history of sick-leave (P < 0.001). They also reported better health, support from superiors, having influence on their working hours and evening and week-end working, longer working hours per week (P < 0.001) and more regular physical training (P < 0.01). Socio-demographic factors were less important than gender, and differences in responses between occupational groups were also found. CONCLUSIONS: Workers without a history of sick-leave experienced less stress, sleep disturbances, worry about their own health and less neck, shoulder and back pain and more support from their superiors and influence on their working hours.

Safety, Tolerability, Pharmacokinetics and Quantitative Electroencephalography Assessment of ACD856, a Novel Positive Allosteric Modulator of Trk-Receptors Following Multiple Doses in Healthy Subjects.

BACKGROUND: ACD856 is a positive allosteric modulator of tropomyosin receptor kinase (Trk) receptors which has shown to have pro-cognitive and anti-depressant-like effects in various animal models. It is currently in clinical development for the treatment of Alzheimer's disease and other disorders where cognition is impaired and is also considered for indications such as depression or other neuropsychiatric diseases. ACD856 has a novel mechanism of action modulating the activity of the Trk-receptors, resulting in increased stimulation of the neurotrophin signaling pathways. Previous studies applying single intravenous and oral doses of ACD856 indicate that ACD856 is safe and well-tolerated by healthy volunteer subjects, and that it has suitable safety and pharmacokinetic properties for further clinical development. OBJECTIVES: To investigate the safety and tolerability of 7 days of treatment with multiple ascending oral doses of ACD856 in healthy subjects, and to characterize its pharmacokinetic (PK) properties. In addition, pharmacodynamic effects of ACD856 using quantitative electroencephalography (qEEG) as an indicator for central target engagement were assessed. DESIGN: This was a prospective, phase I, double-blind, parallel-group, placebo-controlled, randomized study of the safety, tolerability, PK and pharmacodynamics of multiple ascending oral doses of ACD856 in healthy subjects. ACD856 or placebo were administered in 3 ascending dose cohorts of 8 subjects. Within each cohort, subjects were randomized to receive either ACD856 (n=6) or placebo (n=2). SETTING: The study was conducted at a First-in-Human unit in Sweden. PARTICIPANTS: Twenty-four healthy male and female subjects. INTERVENTION: The study medication was administered as an oral solution, with ACD856 or the same contents without the active ingredient (placebo). The dose levels ranged from 10 mg to 90 mg. ACD856 was administered once daily for 7 days, targeting steady state. MEASUREMENTS: Safety and tolerability assessments included adverse events, laboratory, vital signs, 12-lead electrocardiogram (ECG), physical examination, assessment of stool frequency and questionnaires to assess symptoms of anxiety, depression, as well as suicidal ideation and behavior. In addition, cardiodynamic ECGs were extracted to evaluate cardiac safety. PK parameters were calculated based on measured concentrations of ACD856 in plasma, urine, and cerebrospinal fluid (CSF) samples. Metabolite profiling, characterization and analysis was performed based on and urine samples. qEEG was recorded for patients in the two highest dose cohorts (30 and 90 mg/day) as a pharmacodynamic assessment to explore central target engagement. RESULTS: Treatment with ACD856 was well tolerated with no serious adverse events. No treatment emergent or dose related trends were observed for any of the safety assessments. ACD856 was rapidly absorbed and reached maximum plasma exposure at 30 to 45 minutes after administration. Steady state was reached before Day 6, with an elimination half-life at steady state of approximately 20 hours. At steady state, ACD856 exhibited accumulation ratios for Cmax and AUC of approximately 1.6 and 1.9 respectively. The exposure, Cmax and AUC0-24, increased proportionally with the dose. There was no unchanged ACD856 detected in urine. The metabolic pattern in urine and plasma was similar, and in alignment with the metabolites observed in preclinical toxicology studies. The level of ACD856 measured in CSF at steady state increased with dose, indicating Central Nervous System (CNS) exposure at relevant levels for pharmacodynamic effects. ACD856 demonstrated significant dose-dependent treatment-associated changes on qEEG parameters. Specifically, increase of the relative theta power and decrease of the fast alpha and beta power was observed, leading to an acceleration of the delta+theta centroid and an increase in the theta/beta ratio. CONCLUSIONS: ACD856 was well tolerated at the tested dose levels (10-90 mg/daily for 7 days) in healthy subjects. The compound has a robust pharmacokinetic profile, with rapid absorption and dose-dependent exposure. ACD856 was shown to pass the blood-brain-barrier, reach relevant exposure in the CNS and to induce dose-dependent treatment-related changes on qEEG parameters, indicating central target engagement.

Nanoplasma dynamics of single large xenon clusters irradiated with superintense x-ray pulses from the linac coherent light source free-electron laser.

The plasma dynamics of single mesoscopic Xe particles irradiated with intense femtosecond x-ray pulses exceeding 10(16) W/cm2 from the Linac Coherent Light Source free-electron laser are investigated. Simultaneous recording of diffraction patterns and ion spectra allows eliminating the influence of the laser focal volume intensity and particle size distribution. The data show that for clusters illuminated with intense x-ray pulses, highly charged ionization fragments in a narrow distribution are created and that the nanoplasma recombination is efficiently suppressed.

Complement activation products in liquid stored plasma and C3a kinetics after transfusion of autologous plasma.

BACKGROUND AND OBJECTIVES: Keeping a small stock of liquid plasma readily available for transfusion is common practise in Sweden. We report data on complement activation markers in plasma components during storage in the liquid state and the kinetics of C3a-(desArg) after transfusion of autologous plasma with high content of C3a-(desArg). MATERIAL AND METHODS: Plasma components were prepared by apheresis or from whole blood. C3 fragments (C3a-(desArg), C3d,g, iC3), and soluble terminal complement complex (sC5b-9) were investigated. C3a-(desArg) kinetics was investigated in regular apheresis donors. RESULTS: Apheresis plasma prepared by membrane centrifugation had significantly higher level of C3a-(desArg), C3d,g and sC5b-9 from day 0 and low iC3, than plasma prepared by other methods. By storage day 7, C3a-(desArg)-levels were above the reference value in 88% of all components. After re-infusion of autologous plasma with high C3a-(desArg) content, there were rapid a(1) and a(2)-distribution followed by a slower b-elimination phase. CONCLUSION: Plasma components prepared by different methods and stored in the liquid phase differ significantly in the amount and timing of complement activation. C3a-(desArg) present in plasma is rapidly eliminated after transfusion. Autologous plasma could be used to study complement kinetics in different clinical situations.

The antimicrobial peptide LL-37 is anti-inflammatory and proapoptotic in human periodontal ligament cells.

BACKGROUND AND OBJECTIVE: The antimicrobial peptide LL-37 is expressed in periodontal tissue, and variations in LL-37 levels have been associated with periodontal disease. The effects of LL-37 on periodontal ligament cell function have not been described before. Here, we assess anti-inflammatory properties of LL-37 and investigate the effects of LL-37 on cell differentiation, cell proliferation and apoptosis in human periodontal ligament cells. MATERIAL AND METHODS: Periodontal ligament cells were obtained from teeth extracted for orthodontic reasons. Cytokine (interleukin-6) and chemokine (monocyte chemoattractant protein-1) expression was determined by quantitative PCR, cell differentiation by alkaline phosphatase activity, cell proliferation by counting cells in a Bürker chamber, DNA synthesis by incorporation of radiolabeled thymidine and apoptosis by cell morphology and activated caspase 3 quantities. RESULTS: Treatment with 0.1 and 1 µm of LL-37 totally reversed lipopolysaccharide-induced monocyte chemoattractant protein-1 expression and suppressed lipopolysaccharide-induced interleukin-6 expression by 50-70%. LL-37 had no effect on alkaline phosphatase activity. Incubation with 8 µm LL-37 strongly reduced cell number. DNA synthesis was attenuated by about 90% in response to 8 µm LL-37, confirming its antiproliferative effect. Cell morphology was altered in an apoptosis-like fashion in cells treated with 8 µm LL-37. Furthermore, the quantity of activated caspase 3 was increased in cells treated with 1 and 8 µm of LL-37, suggesting apoptosis. CONCLUSION: LL-37 strongly attenuates lipopolysaccharide-induced cytokine and chemokine expression and, in high concentrations, reduces cell proliferation through inhibition of DNA synthesis and by promoting apoptosis in human periodontal ligament cells.

Oncolytic adenovirus modified with somatostatin motifs for selective infection of neuroendocrine tumor cells.

We have previously described the oncolytic adenovirus, Ad(CgA-E1A-miR122), herein denoted Ad5(CgA-E1A-miR122) that selectively replicates in and kills neuroendocrine cells, including freshly isolated midgut carcinoid cells from liver metastases. Ad5(CgA-E1A-miR122) is based on human adenovirus serotype 5 (Ad5) and infects target cells by binding to the coxsackie-adenovirus receptor (CAR) and integrins on the cell surface. Some neuroendocrine tumor (NET) and neuroblastoma cells express low levels of CAR and are therefore poorly transduced by Ad5. However, they often express high levels of somatostatin receptors (SSTRs). Therefore, we introduced cyclic peptides, which contain four amino acids (FWKT) and mimic the binding site for SSTRs in the virus fiber knob. We show that FWKT-modified Ad5 binds to SSTR2 on NET cells and transduces midgut carcinoid cells from liver metastases about 3-4 times better than non-modified Ad5. Moreover, FWKT-modified Ad5 overcomes neutralization in an ex vivo human blood loop model to greater extent than Ad5, indicating that fiber knob modification may prolong the systemic circulation time. We conclude that modification of adenovirus with the FWKT motif may be beneficial for NET therapy.

Complement activation during liver transplantation-special emphasis on patients with atypical hemolytic uremic syndrome.

Atypical hemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy often caused by mutations in complement factor H (CFH), the main regulator of alternative complement pathway. Because CFH is produced mainly by the liver, combined liver-kidney transplantation is a reasonable option in treatment of patients with severe aHUS. We studied complement activation by monitoring activation markers during liver transplantation in two aHUS patients treated extensively with plasma exchange and nine other liver transplantation patients. After the reperfusion, a clear increase in all the activation markers except C4d was observed indicating that the activation occurs mainly through the alternative pathway. Concentration of SC5b-9 was higher in the hepatic than the portal vein indicating complement activation in the graft. Preoperatively and early during the operation, the aHUS patients showed highest C3d concentrations but otherwise their activation markers were similar to the other patients. In the other patients, correlation was found between perioperative SC5b-9 concentration and postoperative alanine aminotransferase and histological changes. This study explains why supply of normal CFH by extensive plasma exchange is beneficial before combined liver-kidney transplantation of aHUS patients. Also the results suggest that perioperative inhibition of the terminal complement cascade might be beneficial if enhanced complement activation is expected.

Black silicon with high density and high aspect ratio nanowhiskers.

The physical properties of black silicon (b-Si) formed on Si wafers by reactive ion etching in chlorine plasma are reported in an attempt to clarify the formation mechanism and the origin of the observed optical and electrical phenomena, which are promising for a variety of applications. The b-Si consisting of high density and high aspect ratio sub-micron length whiskers or pillars with tip diameters of well under 3 nm exhibits strong photoluminescence (PL) both in the visible and the infrared, which is interpreted in conjunction with defects, confinement effects and near band-edge emission. Structural analysis indicates that the whiskers are all crystalline and encapsulated by a thin Si oxide layer. The infrared vibrational spectrum of Si-O-Si bondings in terms of transverse-optic (TO) and longitudinal-optic (LO) phonons indicates that disorder induced LO-TO optical mode coupling can be an effective tool in assessing the structural quality of the b-Si. The same phonons are likely coupled to electrons in visible region PL transitions. Field emission properties of these nanoscopic features are demonstrated indicating the influence of the tip shape on the emission. Overall properties are discussed in terms of the surface morphology of the nanowhiskers.

Estrogen regulates DNA synthesis in human gingival epithelial cells displaying strong estrogen receptor ß immunoreactivity.

BACKGROUND AND OBJECTIVE: Estrogen acts via estrogen receptor (ER) α and ß. The expression pattern of ERs and their importance in gingival tissues are not fully understood. In this study, we investigate gingival ER expression and effects of estrogen on gingival epithelial cell proliferation. MATERIAL AND METHODS: Gingival biopsies were obtained from both healthy and diseased sites in three male and three female subjects. Expression of ERα and ß was determined by immunohistochemistry. Effects of 17ß-estradiol (E(2) ) on cell proliferation, monitored by measuring DNA synthesis, were studied in cultured human gingival epithelial HGEPp.05 cells. RESULTS: Estrogen receptor ß, but not ERα, immunoreactivity was demonstrated in nuclei of epithelial cells in all layers of the gingival epithelium, but also in cells of the lamina propria. No differences were observed between male and female subjects. The same pattern, i.e. high ERß expression but no ERα expression, was observed in both healthy and diseased sites within each individual. No differences in the intensity of the ERß immunoreactive signal and the number of ERß-positive nuclei were observed between healthy and diseased gingiva. Treatment with a physiological concentration of E(2) (10 nm) had no effect on DNA synthesis in ERß- and ERα-expressing HGEPp.05 cells. In contrast, E(2) at high concentrations (500 nm and 10 µm) reduced DNA synthesis by 60-70%. CONCLUSION: Human gingival epithelial cells display strong ERß but low ERα immunoreactivity both in vivo and in culture. Estrogen attenuates gingival epithelial cell DNA synthesis at high but not low concentrations, suggesting a concentration-dependent mechanism.

The human periodontal ligament cell: a fibroblast-like cell acting as an immune cell.

BACKGROUND: Periodontal ligament cells are fibroblast-like cells characterized by collagen production but also possessing some osteoblastic features. In the light of numerous studies presented during recent times, which show that human periodontal ligament cells also produce cytokines and chemokines in response to inflammation promoters, it is reasonable to suggest that periodontal ligament cells play a role as promoters of periodontal inflammation through these mechanisms. MATERIAL AND METHODS: The periodontal ligament, which harbours the periodontal ligament cells, is a part of the attachment apparatus comprised of periodontal ligament cells, extracellular matrix and fibres, attaching the root cement to the alveolar bone. Periodontal ligament cells are in close proximity to bacteria within the plaque and the pocket, and thus these cells are readily accessible to bacterial endotoxins and other promoters of inflammation. RESULTS: Cytokines and chemokines, released by periodontal ligament cells upon stimulation with inflammation promoters, reach the blood vessels easily thanks to rich vascularization of the periodontium stimulating recruitment of white blood cells to the site of inflammation. In addition to classical inflammatory cells, such as leucocytes, macrophages and mast cells, the periodontal ligament cells also contribute to periodontal inflammation via their production and release of cytokines and chemokines. CONCLUSION: Therefore, pharmacological treatment of periodontitis should aim to reduce the release of proinflammatory agents not only from classical inflammatory cells but also from periodontal ligament cells.

Influence of microflora on texture and contents of amino acids, organic acids, and volatiles in semi-hard cheese made with DL-starter and propionibacteria.

The microflora of semi-hard cheese made with DL-starter and propionic acid bacteria (PAB) is quite complex, and we investigated the influence of its variation on texture and contents of organic acids, free amino acids, and volatile compounds. Variation in the microflora within the normal range for the cheese variety Grevé was obtained by using a PAB culture in combination with different DL-starters and making the cheeses at 2 dairy plants with different time and temperature profiles during ripening. Propionic acid bacteria dominated the microflora during ripening after a warm room period at levels of log 8 to log 9 cfu/g, which was about 1 log unit higher than the total number of starter bacteria and about 2 log units higher than the number of nonstarter lactic acid bacteria. Eye formation was observed during the warm room period and further ripening (at 8 to 10°C). The amounts of acetate, propionate, total content of free amino acids, 2-propanol, and ethyl propionate in the ripened cheeses were related to the number of PAB. A decrease in the relative content of Asp and Lys and increase of Phe over the ripening time were different from what is observed in semi-hard cheese without PAB. The occurrence of cracks was higher in cheeses with more hydrolyzed α(S1)- and ß-casein, higher content of free amino acids, lower strain at fracture (shorter texture), and a greater number of PAB.

Incidence, detection and outcome of differentiated thyroid cancer in Western Sweden.

BACKGROUND: It is unclear whether the increasing incidence of thyroid cancer (TC) due to increased diagnosis of small and indolent tumours might mask a real increase of clinically significant cancers. The aim of this study was to correlate surgery, pathology and outcome data of individual patients to the mode of primary detection (palpation, by imaging or incidental) to assess if TC incidence has increased. METHODS: The Swedish Cancer Registry identified all patients with TC in Västra Götaland County representing approximately 1.6 million inhabitants. Clinical information was retrieved from medical records of patient cohorts from three study intervals (2001-2002, 2006-2007 and 2011-2014) comprising 60 per cent of all TC patients. Data were also obtained from the NORDCAN registry to compare of TC incidence with other Nordic countries. RESULTS: Between 2001 and 2014, the annualized standard incidence rate/100 000 population (ASR) of TC increased from 3.14 to 10.71 in women and from 1.12 to 3.77 in men. This was higher than the mean incidence for Sweden but similar to that in Norway and Finland. Differentiated TC (DTC) increased more than threefold. The majority of tumours (64 per cent) were detected by palpation. Larger tumours (10-20, 21-40 and greater than 40 mm) increased as much as microcarcinomas (less than 10 mm). Only 5 per cent of the tumours were detected by imaging. All disease-specific deaths (8.5 per cent of DTC in the first two cohorts) and most patients with recurrent or persistent disease (6.6 per cent of DTC cases) were diagnosed due to tumour-related symptoms. CONCLUSION: DTC in Western Sweden gradually increased between 2001 and 2014. The majority of tumours were detected by palpation suggesting a real increase in the incidence of clinically significant thyroid malignancies.

An ex vivo loop system models the toxicity and efficacy of PEGylated and unmodified adenovirus serotype 5 in whole human blood.

Polyethylene glycol coating (PEGylation) of adenovirus serotype 5 (Ad5) has been shown to effectively reduce immunogenicity and increase circulation time of intravenously administered virus in mouse models. Herein, we monitored clot formation, complement activation, cytokine release and blood cell association upon addition of uncoated or PEGylated Ad5 to human whole blood. We used a novel blood loop model where human blood from healthy donors was mixed with virus and incubated in heparin-coated PVC tubing while rotating at 37 degrees C for up to 8 h. Production of the complement components C3a and C5a and the cytokines IL-8, RANTES and MCP-1 was significantly lower with 20K-PEGylated Ad5 than with uncoated Ad5. PEGylation prevented clotting and reduced Ad5 binding to blood cells in blood with low ability to neutralize Ad5. The effect was particularly pronounced in monocytes, granulocytes, B-cells and T-cells, but could also be observed in erythrocytes and platelets. In conclusion, PEGylation of Ad5 can reduce the immune response mounted in human blood, although the protective effects are rather modest in contrast to published mouse data. Our findings underline the importance of developing reliable models and we propose the use of human whole blood models in pre-clinical screening of gene therapy vectors.

Purified protein derivative of tuberculin induces immunoglobulin production in normal mouse spleen cells.

Purified protein derivative (PPD) tuberculin induced immunoglobulin production in cultures of nonimmune mouse spleen cells, as measured by plaque-forming cells (PFC) against sheep erythrocytes (SRBC), horse erythrocytes, and 4-hydroxy-3,5-dinitrophenacetyl-SRBC. The increase started between 15 and 20 h of culture and reached a peak at 48-72 h. Higher PPD concentrations resulted in earlier peak responses than low concentrations. The Ig produced was mainly 19S and of very low avidity. The response elicited by PPD was of the same type as that caused by lipopolysaccharide of bacterial origin. Mitomycin treatment of cells before culture did not change the numbers of PFC/10(6) recovered cells but the cell recovery was considerably lower. Also injection of PPD in vivo resulted in increased numbers of PFC. On the basis of these results it is suggested that PPD nonspecifically activates a majority of the B cell population to proliferation and immunoglobulin synthesis.

Purification and characterization of a mannose-containing disaccharide obtained from human pregnancy urine. A new immunoregulatory saccharide.

Endogenous mammalian lectin-like sugar-binding molecules have been previously described that have immunoregulatory properties. Further, the addition of defined simple saccharides to lymphocyte cultures has been shown to inhibit a variety of in vitro lymphocyte functions, presumably because these sugars are able to compete with the binding of endogenous lectins to critical membrane receptors. In this report, we describe the isolation and characterization of a D-mannose-containing disaccharide in human pregnancy urine that inhibits the proliferative response of human T lymphocytes. The inhibitory disaccharide was purified to homogeneity by sequential steps including affinity chromatography on immobilized concanavalin A and molecular sizing on Sephadex G-75 and then Fractogel 40S columns, with final purification on high-performance thin-layer chromatography. By mass spectrometry of the purified material as its permethylated derivative, the deduced structure of this compound was alpha-D-Manp 1-6-D-Man. To confirm that this disaccharide was in fact immunosuppressive, an identical disaccharide was prepared by sequential digestion of yeast cell wall polysaccharide. The urinary and yeast disaccharides had identical immunosuppressive properties. It has been previously reported that D-mannose is inhibitory for antigen-specific proliferative assays in the range of 10-50 mM. The purified alpha-D-Manp 1-6-D-Man disaccharide was inhibitory at 100-fold-lower concentrations. Further, while D-mannose inhibits T cell proliferation when added at anytime up to 24 h before harvest of a 6-d lymphocyte culture, alpha-D-Manp 1-6-D-Man disaccharide was inhibitory only if added at the initiation of culture and had no inhibitory effect if added just 24 h later. These data support the concept that simple sugar compounds can exhibit marked immunoregulatory activity in vitro. The impact of these molecules on the regulation of immune responses in vivo is unknown, as is their precise mechanism of action, but structural and chemical identification should now permit a detailed analysis of these issues.

Swimming behavior and prey retention of the polychaete larvae Polydora ciliata (Johnston).

The behavior of the ubiquitous estuarine planktotrophic spionid polychaete larvae Polydora ciliata was studied. We describe ontogenetic changes in morphology, swimming speed and feeding rates and have developed a simple swimming model using low Reynolds number hydrodynamics. In the model we assumed that the ciliary swimming apparatus is primarily composed of the prototroch and secondarily by the telotroch. The model predicted swimming speeds and feeding rates that corresponded well with the measured speeds and rates. Applying empirical data to the model, we were able to explain the profound decrease in specific feeding rates and the observed increase in the difference between upward and downward swimming speeds with larval size. We estimated a critical larval length above which the buoyancy-corrected weight of the larva exceeds the propulsion force generated by the ciliary swimming apparatus and thus forces the larva to the bottom. This modeled critical larval length corresponded to approximately 1 mm, at which, according to the literature, competence for metamorphosis and no more length increase is observed. These findings may have general implications for all planktivorous polychaete larvae that feed without trailing threads. We observed bell shaped particle retention spectra with a minimum prey size of approximately 4 microm equivalent spherical diameter, and we found that an ontogenetic increase in maximum prey size add to a reduction in intra-specific food competition in the various larval stages. In a grazing experiment using natural seawater, ciliates were cleared approximately 50% more efficiently than similar sized dinoflagellates. The prey sizes retainable for P. ciliata larvae covers the microplankton fraction and includes non-motile as well as motile prey items, which is why the larvae are trophically positioned among the copepods and dinoflagellates. Not only do larval morphology and behavior govern larval feeding, prey behavior also influences the feeding efficiency of Polydora ciliata.

Differential regulation of chemokine expression by estrogen in human periodontal ligament cells.

BACKGROUND AND OBJECTIVE: Estrogen modulates inflammatory responses, but the mechanisms involved have not yet been identified. Periodontal ligament (PDL) cells produce chemokines (a group of chemoattractant molecules that recruit leukocytes) and it has been suggested that estrogen modulates periodontal inflammation by regulating the expression of chemokines by PDL cells. Therefore, the objectives of this study were to investigate the regulation of chemokine ligand 2 [CCL2/monocyte chemoattractant protein 1 (MCP-1)], chemokine ligand 3 [CCL3/macrophage inflammatory protein-1α (MIP-1α)] and chemokine ligand 5 (CCL5/RANTES) by estrogen in human PDL cells. MATERIAL AND METHODS: PDL cells were obtained from the PDL of premolars, extracted for orthodontic reasons, from two boys and two girls (16 and 17 years of age). PDL cell CCL2, CCL3 and CCL5 mRNA transcripts were determined by quantitative real-time PCR. The concentrations of CCL2, CCL3 and CCL5 proteins were determined by ELISAs. RESULTS: Treatment with 0.5 µg/mL of lipopolysaccharide (LPS, from Escherichia coli) + 100 nm 17ß-estradiol (E(2) ) for 24 h reduced the expression of CCL3 mRNA by about 40% compared to PDL cells treated with LPS alone. Attenuation of CCL3 mRNA was not associated with a decrease in CCL3 protein within 48 h, suggesting a slow turnover of the CCL3 protein. Interindividual differences in the effects of E(2) on CCL5 mRNA expression were observed. E(2) (100 nm) increased the expression of CCL5 by 40-60% in PDL cells derived from two subjects but reduced the expression of CCL5 by about 30% in cells from another subject. CCL2 mRNA and CCL2 protein were highly expressed, but not regulated by E(2) . Similar data were observed in cells obtained from both boys and girls. CONCLUSION: Regulation, by estrogen, of chemokine expression in PDL cells shows a complex pattern involving the down-regulation as well as the up-regulation of chemokines, suggesting that estrogen exerts both anti-inflammatory and proinflammatory effects through these mechanisms.