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.

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.

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.

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)s as potential nonviral vectors: ability to form interpolyelectrolyte complexes and to mediate transfection in vitro.

Poly(amidoamine)s (PAAs) are water-soluble polymers that display pH-dependent membrane activity. PAAs have the potential to act as a synthetic alternative to fusogenic peptides and thus promote endosomal escape. The purpose of this study was to investigate for the first time whether PAA have the ability to complex DNA, protect it from nuclease degradation and to promote transfection in vitro. PAAs ISA 1 (Mn 6900) and ISA 23 (Mn 10,500) and their 2-phenylethylamine containing analogues ISA 4 and ISA 22 (Mn approximately 8000) were studied. All PAAs retarded the electrophoretic mobility of lambda Hind III DNA demonstrating interpolyelectrolyte complex (IPEC) formation and toroids of 80-150 nm in diameter (10:1 polymer excess) were visible using TEM. DNase II inhibition was observed. At a polymer:DNA ratio of 10:1, this was ISA 1(89.6 +/- 6.1%), ISA 4 (92.2 +/- 11.2%), ISA 22 (69.4 +/- 3.7%), and ISA 23 (58.0 +/- 10.0%). PAAs demonstrated the ability to mediate pSV beta-galactosidase transfection of HepG2 cells. At a vector:DNA mass ratio of 5:1, ISA 23 showed equivalent transfection ability compared with polyethylenimine and LipofectIN and was more effective than LipofectACE. These properties suggest that PAAs warrant further development as endosomolytic vectors.

Immunohistochemical detection of estrogen receptor alpha in male rat spinal cord during development.

The alpha subtype of the estrogen receptor (ERalpha) is present in nociceptive and parasympathetic regions of the adult rat spinal cord. The pattern of ERalpha expression in the rat spinal cord during development, however, is unknown. We used a polyclonal antibody (ER-21) to examine the expression of ERalpha in male rat lumbosacral spinal cords at embryonic day (E) 17, E21 (the day before birth), postnatal day (P) 1 (the day of birth), P8, P17, P21, and P36. At E17, ERalpha immunoreactivity (ERalpha-ir) was observed predominantly in ependymal cells. Perinatally, ERalpha-ir was also present in neurons in dorsal root ganglia and in fibers capping and within laminae I and II. By P8, ERalpha-ir was absent in ependymal cells, but ERalpha-ir fibers were dense in laminae I and II and in sympathetic and parasympathetic areas. ERalpha-ir was also present in neurons in the dorsal horns. To determine whether ERalpha-ir fibers in laminae I and II were processes of spinal neurons or primary afferents, dorsal rhizotomies were performed on P17 and P21 animals. Unilateral transection of the lumbosacral dorsal roots virtually eliminated ERalpha-ir fibers in the ipsilateral superficial laminae, demonstrating that the majority of ERalpha-ir fibers in these laminae were primary afferents. We show for the first time that ERalpha-ir is present in neurons and fibers of male prenatal and postnatal spinal cord. The presence of ERalpha in neuronal nuclei and processes may reflect diverse roles and novel mechanisms of action for 17 beta-estradiol in development of spinal sensory and autonomic circuitry.

Knowledge of HIV serostatus and preventive behaviour among European injecting drug users: second study. European Community Study Group on HIV in Injecting Drug Users.

The objective of the study was to analyse the effect of knowledge of HIV serostatus on behaviours preventing the acquisition or transmission of HIV among European IDU, and to compare results with a previous similar study conducted 3 years before. Data were gathered in 1992-1993 during a retrospective multicentre cross-sectional study of IDU recruited in 11 European countries, in specialized centers and on the street. We compared, between groups with different HIV serological status (IDU who knew well before their HIV-positive serological status, IDU who knew their HIV-negative serostatus and IDU who did not know before their serological status), the respective proportions of IDU who reported that, during the six months prior to interview, (1) always used condoms, (2) never gave their used injecting equipment to other IDU, (3) always injected drugs safely. We only included IDU who had known their serological status for at least six months prior to interview. Results were compared to the similar survey conducted in 1990. From 2171 IDU recruited, data of 1334 IDU were included in the analysis. Compared with IDU who did not know their HIV serostatus, only IDU knowing their HIV-positive serostatus used condoms significantly more often (37% compared to 15%, rate ratio (RR): 2.4; 95% confidence interval (CI): 1.8-2.3) and never gave their used injecting equipment to other IDU (69% compared to 53%, RR: 1.3; 95% CI: 1.2-1.4). In comparison with the 1990 study, only condom use significantly improved and only for IDU who knew their HIV-negative serostatus (13% compared to 9%, RR: 1.6; 95% CI: 1.1-2.3). This study confirms among European IDU the relation between knowing own HIV serological status to preventive behaviours. However, there were only minor improvements between 1990 and 1992-1993, indicating that prevention of HIV transmission among IDU must be reinforced.

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.

Correlation of bacterial indicator organisms with Salmonella spp., Staphylococcus aureus and Candida albicans in sea water.

The value of total coliforms, faecal coliforms and faecal streptococci in predicting the presence of Salmonella spp. and the numbers of Staphylococcus aureus and Candida albicans in sewage polluted coastal water were assessed. All indicators had strong positive association with Salmonella and moderate positive correlations with Staph. aureus and C. albicans. Total coliforms correlated better with salmonellas and Staph. aureus than did the two faecal groups. Regression analysis revealed that total coliforms have a better value as predictors of the presence of Salmonella and Staph. aureus, while faecal coliforms are better predictors of C. albicans, in moderately polluted areas. The conclusion reached is that enumeration of total coliforms is sufficient to predict the presence of Salmonella spp. or Staph. aureus in sea water moderately affected by sewage pollution, without the additional measurement of faecal coliforms and faecal streptococci.

Competencies and problems reported by parents of Greek and American children, ages 6-11.

This study compared parent-reported competencies and behavioral/emotional problems in demographically-matched samples of Greek and American children, ages 6-11. Parents of 356 children of each nationality completed the Child Behavior Checklist (CBCL). Competence scores were higher for American children, except on Academic Competence, where scores were higher for Greek children. Greek scores were significantly higher than American scores on the Withdrawn, Anxious/Depressed, Attention Problems, Delinquent Behavior, Aggressive Behavior, Internalizing, Externalizing, and Total Problem scales. On the Anxious/Depressed syndrome, nationality accounted for 14% of the variance. There were few main effects for sex and age and fewer interactions. The higher problem scores in the Greek sample were partly due to the tendency of Greek parents to use extreme item scores. When items were scored present v. absent, Greek scores were higher only on Withdrawn, Anxious/Depressed, Internalizing, and Total Problems, while American scores were higher on Somatic Complaints and Thought Problems. Nationality differences in rates of referral for mental health services and sample differences in exclusion criteria for prior mental health services may have contributed to differences in problem scores. Results are compared to findings from other cross-cultural studies.

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.

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.

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.

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.

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.

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.

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.