Bioaerosol detection over Athens, Greece using the laser induced fluorescence technique.

The challenge in today's bioaerosol monitoring is to retrieve real-time information on the qualitative and quantitative composition of the ambient air in bioparticles implicated to human health. A pilot study was conducted during March-May 2018 in Athens, Greece in order to detect bioparticles within the Planetary Boundary Layer (PBL) by implementing the LIF LiDAR (Laser-Induced Fluorescence Light Detection and Ranging) technique at an excitation wavelength of 266 nm in order to determine the major components' contribution on the total fluorescence LiDAR signals aloft (30-100 m above our site). The laboratory characterization of the prevalent pollen grains and fungal spores fluorescence signatures enabled through deconvolution the breaking down of the retrieved LIF LiDAR signals and unravelled each bioparticle's contribution. The bioaerosol occurrence and concentration, as determined by the concurrent sampling with a volumetric particle sampler, verified that the detected fluorescence is related to the fungal and pollen aerosol concentration. The results of this study are very promising for the implementation of remote sensing technology in routine detection and quantification of airborne bioparticles in real-time which is important for allergy sufferers and physicians.

The effect of vanadate upon the expression of phenylalanine hydroxylase in streptozotocin-diabetic rat liver.

Induction of diabetes in rats is associated with a significant elevation in the phenylalanine hydroxylating capacity of the liver. This phenomenon reflects an increase in the abundance of both phenylalanine hydroxylase protein and phenylalanine hydroxylase-specific mRNA. These changes can be abolished by insulin-dependent control of diabetes. We show here that the control of diabetes by oral administration of sodium orthovanadate will also nullify the diabetes-related alterations in phenylalanine hydroxylase expression. In addition, diabetes-induced changes in the extent of phosphorylation of phenylalanine hydroxylase are reversed by either insulin or vanadate treatment in vivo. These treatments also abolished the diabetes-related, approx. 30-fold, decrease in glucagon sensitivity of phenylalanine hydroxylation in isolated liver cells.

Is the intimate relationship between ligaments and marginal specialized cells in the snake's spinal cord indicative of a CNS mechanoreceptor?

Large neurons at the ventrolateral edge of the snake's spinal cord are intimately associated with ligaments that closely adhere to the whole length of the spinal cord. Ultrastructural studies show close similarities of these cells and their processes with those of other mechanoreceptors. Furthermore, the ligaments undergo changes within the intervertebral areas that would enhance focusing the stimulus to the receptor area.

alpha,beta-poly(asparthylhydrazide)-glycidyltrimethylammonium chloride copolymers (PAHy-GTA): novel polymers with potential for DNA delivery.

Hydrophilic polycations form complexes when mixed with plasmids. Following functionalisation with glycidyltrimethylammonium chloride (GTA) alpha,beta-poly(asparthylhydrazide) (PAHy), a water-soluble synthetic macromolecule, becomes polycationic and potentially useful for systemic gene delivery. Initially the biocompatibility of PAHy and PAHy-GTA derivatives with different degrees of positive charge substitution were studied and it was shown that PAHy-GTA was neither haemolytic nor cytotoxicity up to 1 mg/ml. After intravenous injection (125)I-labelled PAHy-GTA derivative containing 46 mol% (PAHy-GTA(b)) of trimethylammonium groups did not accumulate in the liver (4.1+/-0.9% of the recovered dose after 1 h) but was subjected to renal excretion (45+/-21% of the recovered dose was in the kidneys after 1 h). PAHy-GTA formed complexes with DNA (gel retardation) and they protected against degradation by DNase II. Finally the ability of the PAHy-GTA(b) derivative to mediate the transfection of HepG2 cells using the marker gene beta-galactosidase was studied. The optimum plasmid/polymer mass ratio was examined in comparison to LipofectACE, Lipofectin and polyethylenimine.

Poly(amidoamine)-mediated intracytoplasmic delivery of ricin A-chain and gelonin.

Poly(amidoamine)s (PAAs) are water-soluble synthetic polymers designed to be biodegradable and biocompatible. Moreover, they display membrane disruptive properties in response to a decrease in pH. This attribute confers PAAs with endosomolytic properties in vitro and in vivo. A model system was developed to quantify their ability to promote the endosomal escape of macromolecules that may be interesting as therapeutic agents. Here, two PAAs (ISA 1 and 4) were incubated with B16F10 cells in vitro together with two non-permeant toxins: either ricin A-chain (RTA) or gelonin. The relatively non-toxic PAAs ISA 1 and 4 (IC50>1.5 mg/ml) restored activity to the inherently inert toxins. The IC50 values for the ISA 1/RTA and ISA 1/gelonin combinations were 0.65+/-0.05 and 0.55+/-0.12 mg/ml, respectively. Similarly, when ISA 4 was incubated with a non-toxic combination of RTA and gelonin the IC50 value decreased to 0.57+/-0.03 and 0.43+/-0.26 mg/ml, respectively. In contrast, the neutral polymer dextran and the PAA ISA 22 were unable to mediate this effect. These observations suggest that specific PAA-toxin combinations warrant further development as novel therapeutics.

Potential of low molecular mass chitosan as a DNA delivery system: biocompatibility, body distribution and ability to complex and protect DNA.

Cationic polymers have the potential for DNA complexation and it is recognised that they may be useful as non-viral vectors for gene delivery. Highly purified chitosan fractions of < 5000 Da (N1), 5000-10,000 Da (N2) and > 10,000 Daltons (N3) were prepared and characterised in respect of their cytotoxicity, ability to cause haemolysis, ability to complex DNA as well as to protect DNA from nuclease degradation. Also the biodistribution of 125I-labelled chitosans was followed at 5 and 60 min after intravenous injection into male Wistar rats. All chitosan fractions displayed little cytotoxicity against CCRF-CEM and L132 cells (IC50 > 1 mg/ml), and they were not haemolytic (< 15% lysis after 1 and 5 h). Chitosan-DNA interaction at a charge ration of 1:1 was much greater than seen for poly(L-lysine) and complexation resulted in inhibition of DNA degradation by DNase II: 99.9 +/- 0.1, 99.1 +/- 1.5 and 98.5 +/- 2.0% for N1, N2 and N3, respectively. After intravenous injection, all the chitosans showed rapid blood clearance, the plasma levels at 1 h being 32.2 +/- 10.5% of recovered dose for N1 and 2.6 +/- 0.5% of recovered dose for N3. Liver accumulation was molecular mass dependent, being 26.5 +/- 4.9% of the recovered dose for N1 and 82.7 +/- 1.9% of the recovered dose for N3. The observations that the highly purified chitosan fractions used were neither toxic nor haemolytic, that they have the ability to complex DNA and protect against nuclease degradation and that low molecular weight chitosan can be administered intravenously without liver accumulation suggest there is potential to investigate further low molecular weight chitosans as components of a synthetic gene delivery system.

Epidemiology of behavioural and emotional problems of primary schoolchildren in Greece.

The behavioural and emotional problems and the competencies of non-referred children in Athens were studied by administering Achenbach's Child Behavior Checklist to the parents of 466 children aged 6-11 years. In comparison to other countries, relatively high scores were obtained on both the internalizing (mean 15.1 for boys and 13.3 for girls) and externalizing scales (16.4 and 18.6), and relatively low scores on the competence scales. Cut-offs for the indication of high risk of behavioural problems suggested by USA data were exceeded by 36% of boys and 39% of girls on the total behaviour scale; appropriate cut-offs (90th percentiles) for use in Greece were re-computed for all scales. Parents' responses to individual behaviour items were analysed in relation to the child's age and sex and the family's socio-economic status. Results are discussed in relation to cultural factors.

Homotypic serum antibody responses to rotavirus proteins following primary infection of young children with serotype 1 rotavirus.

The class-specific antibody responses to serotype 1 rotavirus structural proteins were examined by immunoblotting with sera obtained from young children hospitalized with acute rotavirus diarrhea caused by serotype 1. All were believed to be primary infections. Three consecutive samples were obtained from 16 patients during the acute and convalescent phases of the disease and then approximately 4 months later. Immunoglobulin G (IgG)-class antibody responses to two inner capsid proteins (VP2 and VP6) and to the major homologous outer capsid protein (VP7) were detected in all patients. Antibody responses to VP6 were rapid, increased in intensity during 20 to 40 days after the onset of symptoms, and persisted for more than 4 months. Responses to VP2 and VP7 were more delayed, were maximal in convalescent-phase sera, and decreased markedly in intensity 4 months after the onset of symptoms in the majority of children. Two patients with evidence of mixed infection showed persisting high levels of antibody to VP7. Responses to the outer capsid protein VP4 were detected in 67% of patients, peaked at 20 to 40 days after the onset of symptoms, and were no longer detected at 4 months in the majority of patients. It is likely that the immunoblotting technique underestimated responses to VP4. Acute- and convalescent-phase sera (known to contain antirotavirus IgM or IgA measured by enzyme immunoassay) were also examined by immunoblotting. IgM- and IgA-class antibody responses to viral proteins VP2, VP4, and VP7 appeared to be qualitatively identical to those observed for IgG in the same serum samples.

An update on predeposit autologous blood donation and transfusion in Europe.

BACKGROUND AND OBJECTIVES: The aim of this study was to update previous data on the practice of autologous blood transfusion in Europe. MATERIALS AND METHODS: A questionnaire, mainly about predeposit, was distributed to each National Representative on the Council of Europe's Committee of Experts on Blood Transfusion and Haematology. Detailed replies were received from 23. RESULTS: Predeposit autologous blood units collected in 2000 amounted to 3.3% of the allogeneic units, compared with 4.2% in 1997. Predeposit collection was commonest in Italy (7.8%) and Germany (6.4%). CONCLUSIONS: Although autologous transfusion showed no sign of increase in Europe from 1997 to 2000, the need for alternatives to allogeneic transfusion is growing. Policy and practices in this field should be followed on an ongoing basis.

Characterization of phenylalanine hydroxylase from rat kidney.

1. Phenylalanine hydroxylase has been purified from rat kidney using an immunoaffinity procedure. 2. SDS-PAGE and immunoblot analysis of the purified enzyme revealed subtle differences in the size and abundance of subunits for the enzyme purified from the kidney compared with enzyme purified from the liver. These differences may be explained on the basis of limited proteolysis of the enzyme, during purification from the kidney. 3. The purified renal enzyme is, like the hepatic enzyme, a target for cyclic AMP-dependent protein kinase action. 4. The extent of phosphorylation of the renal enzyme is stimulated by incubation of isolated kidney tubules in the presence of either dibutyryl-cyclic AMP or the protein phosphatase inhibitor, okadaic acid.

Enzyme-linked immunosorbent assays for measurement of reovirus immunoglobulin G, A, and M levels in serum.

Enzyme-linked immunosorbent assays were developed for the quantitation of anti-reovirus immunoglobulin G (IgG), IgA, and IgM in serum. The assays were specific, sensitive, and reproducible and measured antibodies to the reovirus group antigen. They should permit diagnosis of recent reovirus infection and longitudinal study of the development of reovirus group antibodies.

Standardization of the antibody to hepatitis B surface antigen concentration.

We examine sources of potential bias in the estimation of antibody to hepatitis B surface antigen concentrations by a calibration curve for conversion of RIA units to international units. We show by calculation and example that very large biases may exist, whereas accurate estimation is needed in screening programmes and in clinical trials for the evaluation of the immunogenicity of various types and schedules of hepatitis B vaccine. It is recommended that the danger of large biases be avoided by using the laboratory's own calibration curve, calibrated against dilutions of the WHO standard, using a standard as positive control in the radioimmunoassay. Furthermore, serum samples should be diluted to a concentration close to that of the positive control.

Reovirus serotype 3 infection in infants with extrahepatic biliary atresia or neonatal hepatitis.

Infection with reovirus serotype 3 (reo 3) has been postulated to be associated with extrahepatic biliary atresia (EHBA) in infants, and with neonatal hepatitis (NNH). We have investigated this association by assaying antireo 3 antibodies in sera from infants (aged < 4 months) with EHBA (n = 40), NNH (59), cholestatic liver disease due to other causes (61) and control infants with no liver disease (138). Antireo 3 immunoglobulins (Ig) of the G, A and M classes were measured by enzyme-linked immunosorbent assay. No differences in the prevalence of antireo 3 IgG or IgA were found between any of the four groups. A significantly higher prevalence of positive antireo 3 IgM was found in infants with EHBA (12/40), NNH (12/59) or cholestatic liver disease associated with parenteral nutrition (7/17), alpha-1 antitrypsin deficiency (4/15) or a variety of other causes (15/29) compared with control infants (13/138). These data support an association between reovirus 3 infection and cholestatic liver disease in infants. The nature of this association may differ for EHBA, NNH and cholestatic liver disease due to other causes, and remains to be determined.

The role of reversible phosphorylation in the hormonal control of phenylalanine hydroxylase in isolated rat proximal kidney tubules.

Reversible phosphorylation is the major mechanism underlying the short-term hormonal control of phenylalanine hydroxylase activity in the liver. We report here, for the first time, the impact of a range of hormonal effectors on both the phosphorylation state and enzymic activity of phenylalanine hydroxylase present in isolated rat proximal kidney tubules. The most potent stimulator of enzyme phosphorylation was found to be parathyroid hormone, which is known to stimulate the production of cyclic AMP in proximal-tubule cells. In addition, adrenergic amines also stimulated enzyme phosphorylation, although to a lesser extent, through interaction with a mixed alpha 1 and beta receptor population.

Analysis of homotypic and heterotypic serum immune responses to rotavirus proteins following primary rotavirus infection by using the radioimmunoprecipitation technique.

Three sequential serum samples collected from each of 20 young children with a naturally acquired primary rotavirus infection were assayed by the radioimmunoprecipitation technique for immunoglobulin G antibodies to rotavirus structural and nonstructural proteins of the four major human rotavirus serotypes G1, P1A; G2, P1B; G3, P2; and G4, P2. Fourteen children were infected with a serotype G1 rotavirus strain and six children were infected with a serotype G4 rotavirus strain. Sera were collected from each child in the acute and convalescent periods postinfection and also approximately 4 months later. Serum immune responses to rotavirus core antigens VP2 and VP3, to the major inner capsid antigen VP6, to nonstructural proteins NS35, NS28, and NS26, and to the outer capsid neutralization antigen VP4 of all test strains were detected in the majority of patients. These responses do not appear to be influenced by the G type or P type of the rotavirus strain used in the reactions. Homologous responses to the main neutralization antigen VP7 were detected in 93% of patients with serotype G1 infections and 50% of patients with serotype G4 infections. Heterologous VP7 responses were less frequently detected and were restricted to G1, G3, and G4 serotype rotavirus strains. No responses to VP7 of the serotype G2 rotavirus strain were detected in any patients. Heterotypic immune responses to the neutralization antigens, at least following serotype G1 and G4 infections, therefore appear to consist primarily of responses to VP4 rather than to VP7.

Knowledge, attitudes and beliefs of European injecting drug users concerning preventive measures for HIV.

Strategies for controlling the HIV epidemic include education and information campaigns for intravenous drug users (IDUs), as for all high-risk groups, and the provision of various public health measures and treatment. These can only be effective if the IDU is aware of them and has a favourable image of them. A study of 2330 IDUs in 12 European countries recorded awareness and opinions of various categories of measures and institutions. Of all measures, those mentioned most often related to availability of new injecting equipment; specifically unrestricted sales in pharmacies and needle exchanges, which were also thought to be more useful than anything else. Prompted awareness of rehabilitative institutions was well over 90% in most countries, but up to a quarter of IDUs did not trust them and up to one fifth did not think that they were useful. There appears to be a general need for more effective communication with IDUs to improve the image of the services available.