Influence of Membranes on Generation of β2 M and Release of Leukocyte Lysosomal Enzymes

Normal leukocyte functional capacity was investigated by evaluation of phagocytosis of opsonised yeast cells in a radiometric test system. After incubation with dialysis membranes (different cellulosic membranes, polysulfon membrane (PS), polymethylmetacrylate membrane (PMMN), the phagocytosis index, expressed as percent decrease with respect to initial values without membrane, decreased by 10%–25%. The most pronounced effect was observed with PS, cuprophane, modified cellulose and PMMA. The results are not related to differences in the viability of PMN during the test procedure; dead PMN amounted to about 4–6.5%. A significant increase in β-NAG and β-Gluc activities was released in the supernatants of the phagocytosis suspensions. This increase activity can be explained by the phagocytosis of PMN but it was not influenced by membrane contact. There was no influence of membrane contact or phagocytosis activity of PMN on the β2M concentration in the supernatant demonstrating that no in vitro generation during incubation with either membrane exists.

Tick-borne encephalitis in Europe and beyond – the epidemiological situation as of 2007

This review presents an overview of the developments in the epidemiology of tick-borne encephalitis (TBE) during 2007 in Europe, the Far East and Asia, as well as some comments interpreting the various developments. The recent TBE situation in 29 European and four non-European countries is shown and discussed. The number of registered TBE cases from 1976 to 2007 in 19 European countries with endemic TBE is presented. Although criteria for TBE reporting vary from one country to another and it is necessary to account for unreported cases, an overall increase of TBE incidence during the last 30 years can clearly be established. Besides changes in climate and weather, a number of additional factors are probably responsible for this rise: increased exposition, partly due to socio-economical and political changes, and other factors that are for the most part unknown. In addition, the immunisation coverage in the population of some of the countries is discussed.

[Re-evaluation of the risk areas for tick-borne encephalitis in Germany]

In the view of the authors, the present map showing the distribution of the high-risk areas for tick-borne encephalitis is no longer compatible with state of the art information. They therefore call for a re-evaluation of present definitions and a new risk map. Detection of the virus in ticks with the aid of PCR should be given the same weight as an individual clinical case. In future, a differentiation into low-risk, risk and high-risk areas should be avoided.

[Epidemiology of TBE]

In the period between 1974 and 2003, the incidence of TBE increased appreciably in most European countries. Numerous factors, including climatic changes, biological (ecological) and non-biological factors, have an influence on the epidemiology of TBE. In addition, a greater awareness and better understanding (of the problem), improvements in diagnosis, an increase in travel, political and associated major social changes have had an impact on epidemiological data banks. We shall succeed in turning back the rising tide only by achieving further progress in the field of risk analysis, and redoubling our efforts in the area of active immunisation.

[Increasing prevalence of early summer meningoencephalitis in Europe]

The importance of TBE has increased considerably since the mid 70 s in the whole of Europe and Far East. The number of registered clinical cases has risen and risk areas have expanded. For this development a number of factors are responsible ( i. e. global warming, ecological, political, social changes). Because of the high quality and immunogenicity of TBE vaccines available for children and adults TBE should not have to be considered any longer as a problem, subject to the fact that every person at risk has been vaccinated. An important prerequisite for a scientifically based vaccine application are the constant surveillance of TBE risk areas and an actual data base. Epidemiological data with respect to the expansion of risk areas and its level of risk are available covering most European countries with TBE risk and can be made available for medical purposes when travelling.

Tick-borne virus diseases of human interest in Europe

Several human diseases in Europe are caused by viruses transmitted by tick bite. These viruses belong to the genus Flavivirus, and include tick-borne encephalitis virus, Omsk haemorrhagic fever virus, louping ill virus, Powassan virus, Nairovirus (Crimean-Congo haemorrhagic fever virus) and Coltivirus (Eyach virus). All of these viruses cause more or less severe neurological diseases, and some are also responsible for haemorrhagic fever. The epidemiology, clinical picture and methods for diagnosis are detailed in this review. Most of these viral pathogens are classified as Biosafety Level 3 or 4 agents, and therefore some of them have been classified in Categories A-C of potential bioterrorism agents by the Centers for Disease Control and Prevention. Their ability to cause severe disease in man means that these viruses, as well as any clinical samples suspected of containing them, must be handled with specific and stringent precautions.

Durch Zecken übertragene humanpathogene und bisher als apathogen geltende Mikroorganismen in Europa

The importance of tick-borne diseases has significantly increased objectively and subjectively during the last few years. This fact was demonstrated by the description of tick-borne viruses, in particular with respect to tickborne encephalitis published in part I. Here in part II, tick-borne bacteria and parasites will be discussed as well the significance of these agents, their vectors, clinical course, diagnostics, prophylaxis, and therapy. Naturally, Lyme borreliosis, one of the most important tick-borne bacterial illnesses of humans, is the center of our interest. In addition to basic understanding, critical practice-relevant advice regarding all agents is presented. Similarly all tick-borne bacterial diseases such as relapsing fever, tularemia, ehrlichiosis, and rickettsiosis including Q fever will be discussed. Tick-borne zoonotic babesiae are parasites whose veterinary importance has been known for the last 100 years but whose relevance for human medicine only became evident in 1957. The fact that multiple and mixed infections caused by ticks are possible has been known for years. Taking into account such a high prevalence of the infectious agents in ticks, such multiple infections were to be expected. During the last few years it has become evident that double and multiple infections of humans caused by tick bites occur far more frequently than has been known so far. As a result, in cases of unclear anamnesis,new diagnostic and therapeutic approaches should be taken. In general one can say that considerable additional scientific research is necessary to effectively reduce the incidence of tick-borne diseases.

Durch Zecken �bertragene humanpathogene und bisher als apathogen geltende Mikroorganismen in Europa

The importance of tick-borne encephalitis (TBE) and Lyme borreliosis-the main European tick-borne diseases-is steadily growing. This fact is due to many different factors including climate changes. However, across Europe many other human pathogenic viruses, bacteria, and parasites are found in ticks. This article gives an overview of tick-borne human pathogenic viruses present in Europe as well as those considered nonpathogenic. It also deals with the various species of vector-competent ticks. Among these ticks, viruses from 6 families encompassing 8 genera and 35 species are found,whereby the families Flaviviridae, Bunyaviridae, and Reoviridae with the genera flavivirus, nairovirus, and orbivirus are the most prevalent. Because of their special importance Omsk hemorrhagic fever, louping-ill disease, tick-borne encephalitis, and Crimean-Congo hemorrhagic fever are discussed in detail. Although West Nile virus is mainly transmitted to man by mosquitoes, it is discussed in detail, because West Nile fever has become a good example for a new and rapidly spreading vector-borne disease in the USA and for a recurrent one in Europe. Secondly, besides the mosquito-bird cycle an interesting tick--bird cycle is emerging. The overview clearly demonstrates that in Europe (particularly in Germany) tick-borne viruses, with the exception of TBE, constitute an extremely ignored research subject. This lack of attention is in contrast to their importance and results in a lack of necessary scientific data.

[Studies on the importance of tick-borne encephalitis in Rhineland-Pfalz]

Within the scope of a prospective clinical study during 2001 in Rhineland-Palatinate specimen from sera and cerebrospinal fluids of 163 patients with suspected meningitis were controlled in an enzyme immunoassay concerning a TBE infection. Questionable results were checked via a neutralisation test. In no case such an infection was confirmed. No virus specific nucleic acids could be detected in 998 nymphs and adults of Ixodes ricinus in an additional investigation in 2000. Therefore Rhineland-Palatinate has to be considered as a region with low virus prevalence. A general recommendation for vaccination is not necessary.

Annual and seasonal variation of tick-borne encephalitis virus (TBEV) prevalence in ticks in selected hot spot areas in Germany using a nRT-PCR: results from 1997 and 1998

The prevalence of tick-borne encephalitis virus (TBEV) in Ixodes ricinus tick populations in endemic areas of Germany with the highest TBE risk is unknown. Annual and seasonal differences in TBEV prevalence have also not been studied. Against this background, in May 1997 we started a systematic virus surveillance programme in ticks collected in locations known to have a high incidence of autochthonous TBE cases. These were 5 locations in Baden-Württemberg (Black Forest) and 8 locations in Bavaria (surrounding Passau). Field-collected ticks were randomly assigned to pools of 10 adults or 20 nymphs, respectively. The tick pools were tested for the presence of TBEV-RNA using a newly developed, sensitive nested reverse transcriptase polymerase chain reaction assay (nRT-PCR). The primer pairs were selected from the 5'-terminal noncoding region, a highly conserved part of the virus. The specificity was tested by computer homology searches of sequences, as well as by sequencing of the first and the second amplificates, by Southern blot hybridisation with a DIG-labelled oligonucleotide probe, and by restriction enzyme analysis. The method has proved to be very sensitive, with a detection limit of 20 fg of TBEV RNA per PCR run, or a single positive tick. Based on biostatistical considerations a sample size of at least 1000 ticks per estimation point was chosen. The estimated TBEV prevalence and confidence intervals (CI) were calculated from the nRT-PCR results of pooled samples (10 adults or 20 nymphs) using appropriate formulae for pooled testing. In order to identify the estimated TBEV prevalence as well as to assess the influence of annual and seasonal factors on TBEV prevalence, ticks were sampled twice a year (May and September) in 1997 and 1998 at exactly identical sites. These sites were selected because they were known to have had the highest incidence of autochthonous TBE cases during the previous 10 years. On sampling days, relevant local meteorological data were also noted. In total, 8500 I. ricinus ticks were investigated in this study, 4270 (3540 nymphs, 730 adults) from the Black Forest habitats, and 4230 (3680 nymphs, 550 adults) from the Bavarian locations. In the foci near Freiburg (Black Forest), the estimated virus prevalence was relatively high in the whole tick population, during 1997 with only slight seasonal differences [3.4% (confidence interval, CI, 2.3-4.8%) in May and 2.9% (CI 1.7-4.5%) in September]. In contrast, in 1998, in the same foci the estimated TBEV prevalence was considerably lower [1.1% (CI 0.5-2.0%) in May and 0.6% (CI 0.2-1.4%) in September]. Thus, while the seasonal differences again remained low, the annual variation was marked. In the Bavarian foci in 1997, the estimated virus prevalence of the whole tick population studied was lower than in the Black Forest foci and the seasonal fluctuations were low: in May 1997 0.9% (CI 0.4-1.8%) of the ticks were positive, in September 1.1% (CI 0.5-1.9%). In 1998, in May 2.0% (CI 1.1-3.3%) of the ticks were positive, and in September 1.1% (CI 0.5-2.1%). For the whole study period, every 50th to 100th I. ricinus nymph or adult in the Passau region was calculated to give a positive signal in the nRT-PCR. The TBEV prevalence data indicate that residents and visitors of areas in Germany known for high endemic activity take a significant risk of contracting TBEV infection, if bitten by ticks. In addition, the data suggest that annual fluctuations may exist in the whole tick population studied. Seasonal fluctuations of the virus prevalence in ticks were small.

Estimating the prevalence of infectious agents using pooled samples: biometrical considerations

Pooled testing of units is a common approach in the prevalence estimation of infectious agents, which leads to a reduction of total costs of diagnostic testing. We examine how the pool size affects the statistical properties of the prevalence estimator r. Exact formulae are used to determine bias and precision of r. It is shown that with moderate pool sizes the (upward) bias of r is negligible. If there is no diagnostic error, the random error of r increases slightly with higher pool sizes, whereas if sensitivity and specificity are lower than 1, pooling may markedly decrease the random error of r. Another reason why pooling may be beneficial (and even indispensable) is that it greatly reduces the huge bias that can result if the assumed values of the sensitivity and specificity of the diagnostic test are not equal to the true values. The numerical calculations show that, in case of prevalence rates of up to 5% and total sample sizes of n > or = 500, pool sizes of about 10 to 20 are generally satisfactory from a statistical view-point. The methodological advantages and disadvantages of more complicated pooling strategies involving repeated testing of units are discussed.

A nested RT-PCR for the detection of tick-borne encephalitis virus (TBEV) in ticks in natural foci

We have developed a sensitive nested reverse-transcriptase polymerase chain reaction assay (n RT-PCR) for the detection of the tick-borne encephalitis virus (TBEV) RNA, especially in ticks. The primer pairs were selected from the 5'-terminal noncoding region, a highly conserved part of the virus. The specificity was tested by computer homology searches of sequences as well as by the sequencing of the first and second amplificate, by Southern blot hybridization with a DIG-labelled oligonucleotide probe, and by restriction enzyme analysis. The method has proved to be very sensitive. The detection limit is about 20 fg of TBEV RNA per PCR run (25 microliters), or a single positive tick, i.e. (adult or nymph). The method can be used for comparative studies of the epidemiological situation, as well as for the screening of natural foci for the presence and circulation of TBEV or for the detection of TBEV-genome-sequences in clinical materials.

Viral zoonosis from the viewpoint of their epidemiological surveillance: tick-borne encephalitis as a model

Tick-borne encephalitis (TBE) is a vector borne and, more rarely, a food (milk, milk products) borne disease of humans. For further characterization of the virus activity in natural foci of TBE more than 32,000 unengorged wild ticks were caught in low and high virus active foci in Germany (Mecklenburg-Western Pomerania, Saxony, Brandenburg, Thuringia, Bavaria, Baden-Württemberg, Saarland). The ticks were examined by RT-PCR and Southern blot hybridization as well as by classical virological methods. The dynamics of such natural foci of TBE in the last 35 years were discussed. Also nucleotide sequence data of parts of the virus genome (5'-non coding region) of 16 European and some Far East subtype strains were compared.

Tick-borne encephalitis virus (TBEV)-specific RT-PCR for characterization of natural foci of TBE and for other applications

An effective detection system for TBEV-RNA sequences using a RT-PCR technique has been developed. In our system, specific oligonucleotide primers corresponding to the 5'-terminal noncoding region were successfully used to identify TBEV sequences in ticks. To prove the specificity of the PCR products, Southern blot hybridization with an internal digoxigenin-labelled probe was carried out. In this paper, we present some potential applications of this technique. The primers were used to identify 21 TBEV strains isolated in different years, in different geographic regions and from different sources. 22313 Ixodes ricinus ticks from north-east Germany were analyzed for TBEV-specific sequences in order to characterize the viral activity in natural foci of TBE. In the new Federal Länder, only 6 samples gave positive PCR-results, showing that the natural foci of TBE had not been extinguished but remained in a state of endemic latency. We also used the RT-PCR to develop an animal model to investigate the temporal pattern of viraemia in the Mongolian gerbil (Meriones unguiculatus) through xenodiagnosis (sequential tick feeding on an infected host and subsequent RT-PCR testing of the resultant engorged ticks).

Survey of the hemagglutinin (HA) cleavage site sequence of H5 and H7 avian influenza viruses: amino acid sequence at the HA cleavage site as a marker of pathogenicity potential

The deduced amino acid sequence at the hemagglutinin (HA) cleavage site of 76 avian influenza (AI) viruses, subtypes H5 and H7, was determined by reverse transcription-polymerase chain reaction and cycle sequencing techniques to assess pathogenicity. Eighteen of the 76 viruses were isolated in 1993 and 1994 from various sources in the United States. In addition, 34 H5 (4 highly pathogenic [HP] and 30 non-highly pathogenic [non-HP]) and 24 H7 (3 HP and 21 non-HP) repository viruses, isolated between 1927 and 1992, were sequenced and the sequences compared to those in recent isolates. All repository HP H5 and H7 viruses studied had multiple basic amino acids adjacent to the HA cleavage site and most had basic amino acids in excess of the proposed minimum motif B-X-B-R (B = basic amino acids arginine or lysine, X = nonbasic amino acid, R = arginine) that has been associated with high pathogenicity. Of the non-HP viruses studied, 35 of 38 for H5 and 30 of 31 for H7 conformed to the motif B-X-X-R and B-X-R, respectively. Two non-HP H5 viruses had the motif X-X-X-R at the cleavage site and a third had the motif B-X-X-K (K = basic amino acid lysine). One non-HP H7 (A/Pekin robin/CA/30412-5/94) had four basic amino acids (K-R-R-R) adjacent to the cleavage site. Although the Pekin robin isolate did not produce disease in chickens under the conditions of the study it did have the amino acid sequence compatible with that in HP AI viruses and, therefore, is considered potentially HP. This is the first account of an H7 virus that is non-HP in chickens but meets the molecular criterion to be classified as HP.

Detection of the tick-borne encephalitis virus (TBEV) in ticks in several federal "Länder" of Germany by means of the polymerase chain reaction (PCR)--characterization of the virus

The aim of the present study was to analyse the current epidemiological situation with respect to TBE in the new federal "Länder" of Germany and in Saarland through detection of the TBEV genome in unengorged ticks using an RT-PCR technique. 22,273 ticks (Ixodes ricinus) were collected in the five new "Länder" (and some in Bavaria and Baden-Württemberg) and divided into 294 pools. It was possible to detect TBEV RNA in six pools of ticks from Mecklenburg Western-Pomerania [4], Brandenburg [1], Thuringia [1] (and in three pools from Bavaria and Baden-Württemberg). The nucleotide sequence data of the PCR products were analysed and compared. In Saarland 8,780 ticks were collected in 70 habitats from all the geographic regions and analysed using the PCR in 21 pools; two pools produced positive PCR signals (Saarlouis, Perl). We cannot as a result make a general recommendation that TBE-immunization be introduced in Saarland and in the new federal Länder of Germany. In Germany, however, TBE immunoprophylaxis in Bavaria and Baden-Württemberg is very important.

Characterization of a 105-kDa polypeptide encoded in gene 1 of the human coronavirus HCV 229E

Gene 1 of the human coronavirus HCV 229E encompasses approximately 20.7 kb and contains two overlapping open reading frames, ORF 1a and ORF 1b. The downstream ORF 1b is expressed by a mechanism involving (-1) ribosomal frameshifting. Translation of mRNA 1, which is thought to be equivalent to the viral genomic RNA, results in the synthesis of two large polyproteins, pp1a and pp1ab. These polyproteins contain motifs characteristic of papain-like and 3C-like proteinases, RNA-dependent RNA polymerases, helicases, and metal-binding proteins. In this study, we have produced pp1ab-specific monoclonal antibodies and have used them to detect an intracellular, 105-kDa viral polypeptide that contains the putative RNA polymerase domain. Furthermore, using trans cleavage assays with bacterially expressed HCV 229E 3C-like proteinase, we have demonstrated that the 105-kDa polypeptide is released from pp1ab by cleavage at the dipeptide bonds Gln-4068/Ser-4069 and Gln-4995/Ala-4996. These data contribute to the characterization of coronavirus 3C-like proteinase-mediated processing of pp1ab and provide the first identification of an HCV 229E ORF 1ab-encoded polypeptide in virus-infected cells.

Different hemagglutinin cleavage site variants of H7N7 in an influenza outbreak in chickens in Leipzig, Germany

The hemagglutinin (HA) genes from four avian H7N7 influenza A isolates, from a single outbreak, were shown to possess different cleavage sites that contain varying numbers of basic amino acid residues (KKKKR, KRKKR, KKRKKR, KKKKKKR). All four variants are highly pathogenic in chickens and share an immediate common ancestral HA with A/tern/Potsdam/342-6/79 (H7N7) and A/swan/Potsdam/63-6/81 (H7N7). These viruses are nonpathogenic and contain no extra basic amino acids at the cleavage site of their HA. During evolution a common precursor virus acquired different sequences at the cleavage site of the HA and became highly pathogenic in chickens. In vitro assays revealed that the HA from A/chicken/Leipzig/79 with KKKKR at the cleavage site was only partially cleaved (41%), compared to 93-100% cleavage of the other HAs. Since all four viruses were highly pathogenic in chickens, these findings confirm that the degree of pathogenicity in vivo is not exclusively determined by the degree of HA cleavability.

Characterization of a novel influenza hemagglutinin, H15: criteria for determination of influenza A subtypes

Two viruses with a novel hemagglutinin (HA), A/duck/Australia/341/83 and A/shearwater/West Australia/2576/79, have been isolated from a duck and a shorebird in Australia. Hemagglutination inhibition and double immunodiffusion assays failed to reveal cross-reactivity with any of the known subtypes (H1 to H14). We therefore propose that these viruses constitute a new HA subtype, H15. Sequence analysis of the HA genes confirmed the serologic findings. When compared at the amino acid level, the HA1 region of the H15 subtype differs from those of the other subtypes by 30% and more. This degree of heterogeneity is also found among HA genes of other subtypes. Thus we propose that amino acid sequence data should be evaluated when determining the HA subtypes of influenza A viruses. Sequence comparison and phylogenetic analysis suggested that the HA subtype H15 is most closely related to the H7. Compared to the H7 HA, the H15 acquired a 30-nucleotide insertion within HA1 at position 253 which is located in the globular head of the molecule. This finding suggests that RNA recombination, although a rare event in nature, may play an important role in the evolution of influenza viruses.

Do hemagglutinin genes of highly pathogenic avian influenza viruses constitute unique phylogenetic lineages?

Avian influenza A viruses of the H5 and H7 subtypes periodically cause severe outbreaks of disease in poultry. The question we wished to address in this study is whether these highly pathogenic strains constitute unique lineages or whether they and related nonpathogenic viruses are derived from common ancestors in the wild bird reservoir. We therefore compared the nucleotide and amino acid sequences of the hemagglutinin (HA) genes of 15 H5 and 26 H7 influenza A viruses isolated over 91 years from a variety of host species in Eurasia, Africa, Australia, and North America. Phylogenetic analysis indicated that the HA genes of H5 and H7 viruses that cause severe disease in domestic birds do not form unique lineages but share common ancestors with nonpathogenic H5 and H7 viruses. These findings predict that highly pathogenic avian H5 and H7 influenza A viruses will continue to emerge from wild bird reservoirs. Another important question is whether H7 influenza viruses found in mammalian species are derived from avian strains. We included eight equine influenza viruses and one seal isolate in the phylogenetic analysis of H7 HA genes. We could show that the HA genes of both, the equine and the seal viruses, shared ancestors with avian H7 HA genes. This indicates that currently circulating H7 viruses with an avian HA gene may have the potential to adapt to mammalian species and to cause an influenza outbreak in the new host.

Rapid detection of tick-borne encephalitis virus sequences by cDNA amplification coupled to a simple DNA enzyme immunoassay

BACKGROUND

The tick-borne encephalitis virus (TBEV) causes many cases of severe neurological disease in Europe and Asia. Rapid and virus specific laboratory tests are needed for epidemiological studies and for diagnosis of human diseases.

OBJECTIVES

A newly developed colorimetric method, DNA enzyme immunoassay (DEIA), was applied to the detection of TBEV-specific sequences.

STUDY DESIGN

Reverse transcription and polymerase chain reaction (PRC) were used for g genomic amplification. The specificity of PCR products was confirmed using an internal biotinylated probe from the 5'-NCR immobilized on streptavidin coated microtiter wells. The hybridization event was revealed by monoclonal antibodies to double stranded DNA in a standard ELISA reaction.

RESULTS

A total of 23 TBEV strains among them prototype strains and isolates from Germany and other European countries was investigated. In all cases hybridization with the internal probe has occurred.

CONCLUSION

The DEIA described here is a simple and rapid method facilitating the handling of a large number of samples and therefore seems to be especially valuable to surveillance studies of endemic areas and for diagnosis of human diseases.

[Increased mortality in home delivery]

103 current publications on perinatal mortality of home delivery (HD) have been investigated concerning their possible usage for statistics. Only few could meet the necessary statistical requirements. All publications which were in favour of home delivery showed statistical faults; therefore, they cannot give clear evidence of advantages and disadvantages of HD. The group of the described HD (approximately 85,000 home deliveries) were compared with a statistically comparable group of hospital deliveries. The risk for children to die during or after birth is between 3 and 23 times higher for home-born children than for those born in hospitals. The rate of unexpected incidents during delivery, where transport to hospital was required, is about 11%; this corresponds to the rate of unexpected incidents in hospitals. In home delivery, it is not possible to provide obstetrical operative interventions. The frequency of operatively terminated deliveries is about 40% in the group of secondarily transferred patients. The Netherlands have about 30% home deliveries; their perinatal mortality rate (0.96%) is the highest of all comparable high-developed countries (Germany: 0.6%). Considering the necessary safety of the child, home delivery is irresponsible.

Influenza virus subtypes in aquatic birds of eastern Germany

We report the findings of a 12-year surveillance study (1977-89) of avian influenza A viruses in eastern Germany. Viruses were isolated directly from feral ducks (n = 236) and other wild birds (n = 89); from domestic ducks (n = 735) living on a single farm; and from white Pekin ducks (n = 193) used as sentinels for populations of wild aquatic birds; mainly sea birds. The efficiency of virus isolation was 9.9% overall, with considerable variability noted among species: 8.7% in wild ducks, 0.9% in other feral birds and 38% in Pekin ducks. Use of sentinel ducks in wild pelagic bird colonies improved virus detection rates fivefold, suggesting that this approach is advantageous in ecological studies. Among the 40 different combinations of hemagglutinin (HA) and neuraminidase (NA) subtypes we identified, H6N1 predominated (23.6% for all avian species), followed by H4N6 (11%). Among individual species, the frequency profiles favored H2N3 (20.8%) and H4N6 (20.3%) in feral ducks; H7N7 (22.3%), H4N6 (24.4%) and H2N3 (10.4%) in Pekin ducks used as sentinels; and H6N1 (34.8%) and H6N6 (15.1%) in domestic ducks maintained on a single farm. By relying on sentinel birds for serological assays, it was possible to trace an "influenza season" in feral swan populations, beginning in August and continuing through the winter months. Comparison of subtype distribution of influenza viruses for Europe and North America showed significant differences. This supports the fact of two geographically distinct gene pools of influenza viruses in birds connected with their distinct flyways of each hemisphere. The high frequency of isolation of H2 influenza viruses is of considerable interest to those interested in the recycling of this subtype in humans. Similarly the frequent isolation of H7N7 influenza viruses raises concern about reservoirs of potentially pathogenic influenza virus for domestic poultry. Our results confirm the existence of a vast reservoir of influenza A viruses in European aquatic birds, which possesses sufficient diversity to account for strains that infect lower animals and humans.

Detection of tick-borne encephalitis virus RNA in ticks (Ixodes ricinus) by the polymerase chain reaction

A polymerase chain reaction for the detection of tick-borne encephalitis virus (TBEV) RNA in ticks was developed. Two pairs of primers for nested PCR were selected from the 5'-NCR and the 5'-terminus of the C protein coding region, which are highly conserved among the TBEV isolates sequenced so far. The sensitivity of the nested PCR was tested by dilution experiments of a TBEV positive brain suspension. The specificity of the PCR products was confirmed by Southern blotting. In a pilot study, 60 homogenates of 7200 ticks (I. ricinus) were examined by PCR. Two homogenates were found positive. The PCR for TBEV RNA appears to be a valuable method to define endemic areas of TBE.

[The early history of the negative feedback of estrogens on gonadotropins of the anterior hypophysis. The priority dispute between Dorothy Price and Walter Hohlweg. A contribution to self-deception in scientific priority claims]

From printed manuscripts of lectures held in August 1930 in London, we learn, that Carl R. Moore and Dorothy Price from Chicago, as well as Max Dohrn and Walter Hohlweg from Berlin, deduced, from different experiments, a negative feedback of oestrogens on the gonadotropic function of the anterior pituitary and--in general--a kybernetic system between pituitary and ovary. In 1975, both Price and Hohlweg claimed to be the discoverer of that system. A historical analysis reveals, that these priority claims are open to doubt.

Origin of the pandemic 1957 H2 influenza A virus and the persistence of its possible progenitors in the avian reservoir

H2N2 influenza A viruses caused the Asian pandemic of 1957 and then disappeared from the human population 10 years later. To assess the potential for similar outbreaks in the future, we determined the antigenicity of H2 hemagglutinins (HAs) from representative human and avian H2 viruses and then analyzed the nucleotide and amino acid sequences to determine their evolutionary characteristics in different hosts. The results of longitudinal virus surveillance studies were also examined to estimate the prevalence of avian H2 isolates among samples collected from wild ducks and domestic poultry. Reactivity patterns obtained with a large panel of monoclonal antibodies indicated antigenic drift in the HA of human H2 influenza viruses, beginning in 1962. Amino acid changes were clustered in two regions of HA1 that correspond to antigenic sites A and D of the H3 HA. By contrast, the antigenic profiles of the majority of avian H2 HAs were remarkably conserved through 1991, resembling the prototype Japan 57 (H2N2) strain. Amino acid changes were distributed throughout HA1, indicating that antibodies do not play a major role in the selection of avian H2 viruses. Phylogenetic analysis revealed two geographic site-specific lineages of avian H2 HAs: North American and Eurasian. Evidence is presented to support interregion transmission of gull H2 viruses. The human H2 HAs that circulated in 1957-1968 form a separate phylogenetic lineage, most closely related to the Eurasian avian H2 HAs. There was an increased prevalence of H2 influenza viruses among wild ducks in 1988 in North America, preceding the appearance of H2N2 viruses in domestic fowl. As the prevalence of avian H2N2 influenza viruses increased on turkey farms and in live bird markets in New York City and elsewhere, greater numbers of these viruses have come into direct contact with susceptible humans. We conclude that antigenically conserved counterparts of the human Asian pandemic strain of 1957 continue to circulate in the avian reservoir and are coming into closer proximity to susceptible human populations.

Epidemiology and ecology of tick-borne encephalitis in the eastern part of Germany between 1960 and 1990 and studies on the dynamics of a natural focus of tick-borne encephalitis

From 1960 to 1990, attempts to isolate TBE virus from ticks and small mammals were made and investigations to detect TBE antibody in small mammals, game and humans were performed in the five new federal Länder of Germany. The confirmed TBE cases for which the site of exposure could be determined were also registered. As a result of these epidemiological and ecological investigations, a map is presented showing the natural foci of TBE which are primarily located in the subatlantic and mountainous climatic regions. TBE was endemic in the area of investigation from 1960 to 1990 showing a morbidity of up to 0.7 per 100,000 inhabitants which decreased in recent years to 0.02 per 100,000 inhabitants. The natural foci of TBE virus in eastern Germany showed a high activity between 1960 and 1970. Since that time, there have hardly been any cases of human disease and TBE virus could no longer be detected, neither in ticks nor in small mammals. Taking the natural focus on the Island of Usedom as an example, attempts have been made to elucidate whether such foci have become extinct or whether they have persisted. From 1983 to 1989, a surveillance programme was performed to detect antibodies to TBE virus in small mammals and game and to attempt to culture virus from ticks and small mammals. The attempts to isolate virus from a total of 8200 ticks were negative. Attempts to isolate virus from the brains of small mammals were also negative. Antibody prevalence in 446 small mammals and 500 animals of game was ca. 1%. At one site, the sero-positive reactions converted from 0% (1983-1988) to 4.5% (1989) among small mammals population. The investigations performed on the Island of Usedom have shown that this natural focus has not disappeared but is in a state of endemic latency. Moreover, the seroconversion observed in the small mammals population shows that further surveillance of such foci is necessary. This becomes obvious by the sporadic occurrence of single TBE cases as well as by a low antibody prevalence of 1% in small mammals and game. The epidemiological situation in eastern Germany is thus completely different from that in western Germany where an average of 70-120 TBE cases per year are registered, occurring mainly in Bavaria and Baden-Württemberg.

In vitro phagocytosis by crevicular phagocytes in various forms of periodontitis

Phagocytes from the gingival crevice fluid (CF-cells) of 11 patients with localized juvenile and post-juvenile periodontitis (LJP/PJP), 14 with rapidly progressive periodontitis (RPP), 11 with adult periodontitis (AP), and 14 controls without periodontal disease were examined. Phagocytic activity in vitro was assessed. Crevicular washings were obtained from healthy sites of controls and diseased sites of patients after completion of the oral hygiene phase (professional and home care). The cells were carefully processed to avoid mechanical damage. The in vitro phagocytosis by uptake of opsonized C. albicans was performed in a moist chamber (30 minutes, 37 degrees C) and examined by light microscopy. CF-cells were differentiated on the basis of their morphological appearance. The majority of cells in crevicular washings were PMNs, some macrophages, and few lymphocytes. Phagocytic activity in patients with LJP/PJP and RPP was significantly decreased in comparison with that from AP and the control group. The decreased percentage of cells phagocytosing opsonized C. albicans was associated with the enhanced adherence of opsonized C. albicans. Moreover cell viability of CF-cells from LJP/PJP sites was significantly reduced. The data from the present study suggest that the in vitro phagocytosis of crevicular phagocytes in juvenile and rapidly progressive periodontitis lesions is diminished.

Analysis of internal proteins of influenza A (H2N2) viruses isolated from birds in East Germany in 1983

Proteins and RNAs of influenza A (H2N2) viruses isolated from birds in 1983 in East Germany were compared antigenically with those of H2N2 human strains. The electrophoretic mobility of the viral proteins and of the S1-treated double-stranded RNAs from two human and six avian strains, as well as the results of EIA-tests using monoclonal antibodies to their matrix protein and nucleoproteins indicate an antigenic relationship between the avian isolates and human strains of H2N2 subtype. One of the avian strains had a reduced amount of matrix protein.

The Zimmermann-Laband syndrome

We report on two patients who exhibit the typical features of the rare Zimmermann-Laband syndrome such as gingival fibromatosis, swelling of perioral tissues, nail hypo/aplasia, and abnormalities of terminal phalanges. The older patient suffers from epileptic seizures and shows osseous mandibular hypertrophy, two maxillary mesiodentes and lumbar spondylodysplasia. In the 2nd patient, a 3 year old male, the characteristic morphological features are already present.

[The effect of potential antineoplastic antibiotics and the metal complex compound cisplatin on in vitro phagocytosis]

Under standardized conditions the influence of the drugs lambdamycin, violamycin, granatomycin C, daunorubicin and cisplatin on the phagocytosis has been tested. Therapeutical doses of lambdamycin, daunorubicin and cisplatin did not have any obvious impairment on the phagocytosis. Contrarily to this granatomycin C (an isochromanchinon antibiotic) and violamycin (an anthracyclin in high concentrations) significantly depressed the phagocytosis of PMN.

[Acute infantile cerebral form of Gaucher disease]

A foetus causing attention by disharmonic growth retardation and suspected CTG, died within the 34th week of gestation. The infantile cerebral form (type II) of Gaucher's disease was detected by histological examination. In another pregnancy a second afflicted child was discovered by decreased cerebroside-beta-glucosidase activity in amniotic fluid cells. Abortion was therefore induced.

A phagocytosis capacity assay: parallel measurement of the phagocytosis and the intracellular killing in granulocytes and the influence of some substances on these processes

A radiometric technique is described for the assessment of phagocytosis and killing of viable yeast cells by granulocytes. This technique does not require separation of extra- and intracellular microorganisms. In this method the phagocytes which contain viable yeast cells (Saccharomyces cerevisiae and Candida albicans) were disrupted by Triton X-100, and only the remaining yeast cells were isotope-labelled. The uptake of [75 Se]L-selenomethionine was used to measure the killing ability of phagocytes. This method is recommended to measure the influence of biological and pharmacological agents to ingest and kill leucocytes in vitro. The following substances affected phagocytosis and killing: Granatomycin C (decreased phagocytosis), cis-DDP (no influence), bestatin (stimulation of phagocytosis) and Z 190/69-HCl (oxazole) (stimulation of phagocytosis and killing).

[A solitary central maxillary incisor and holoprosencephaly in siblings]

In families in which holoprosencephaly seems to be inherited by a rare dominant autosomal mutation, some individuals exhibit a single central maxillary incisor (SCMI). This anomaly was considered a minimal manifestation of the gene for holoprosencephaly. We report on a family, in which one child suffered from median cleft lip and palate and alobar holoprosencephaly, whereas the other child only had a SCMI. In the father and his sister lateral upper incisors were absent. Therefore the question is raised as to whether this anomaly may be related to the same condition.

Influence of membranes on generation of beta 2 M and release of leukocyte lysosomal enzymes

Normal leukocyte functional capacity was investigated by evaluation of phagocytosis of opsonised yeast cells in a radiometric test system. After incubation with dialysis membranes (different cellulosic membranes, polysulfon membrane (PS), polymethylmetacrylate membrane (PMMN), the phagocytosis index, expressed as percent decrease with respect to initial values without membrane, decreased by 10%-25%. The most pronounced effect was observed with PS, cuprophane, modified cellulose and PMMA. The results are not related to differences in the viability of PMN during the test procedure; dead PMN amounted to about 4-6.5%. A significant increase in beta-NAG and beta-Gluc activities was released in the supernatants of the phagocytosis suspensions. This increase activity can be explained by the phagocytosis of PMN but it was not influenced by membrane contact. There was no influence of membrane contact or phagocytosis activity of PMN on the beta 2 M concentration in the supernatant demonstrating that no in vitro generation during incubation with either membrane exists.

Birch sap and birch leaves extract: screening for antimicrobial, phagocytosis-influencing, antiphlogistic and antipyretic activity

Birch sap and birch leaves extract have been screened for antimicrobial, phagocytosis-influencing, anti-inflammatory and antipyretic activity. No antimicrobial effects could be detected in the agar-diffusion test with staphylococcus as test strain, whereas birch sap exhibited some inhibitory effect on phagocytosis, which exceeded that of the citric acid added to the birch sap as preservative. In rats, only the high doses of 1 and 2 ml/100 g b.m. birch sap had a weak and short-lasting anti-inflammatory activity against the Carrageenin edema, whereas birch leaves extract proved to be ineffective. Fever induced by baker's yeast in rats was inhibited by birch leaves extract in the high dose of 4 ml/100 g b.m. significantly, but not by birch sap, and only for a short period. Acetylsalicyclic acid had a much higher anti-inflammatory and antipyretic activity. Altogether despite of detectable anti-inflammatory, antipyretic and phagocytosis-inhibiting effects of these birch products no therapeutic activity of importance compared with classical and modern antipyretics-analgetics can be demonstrated.

Development of mathematical models for an in vitro-phagocytosis test system

Phagocytosis tests have been carried out by many authors using different methods under different conditions. The results have been interpreted in different ways, as well sometimes with conflicting notations. In order to get to a more systematic data analysis and to separate intrinsic from methodic influences, the possibility to apply mathematical models to a phagocytosis test has been studied. In agreement with previous experiences that phagocytosis can well be represented by a mathematical treatment as Michaelis-Menten-type enzyme kinetics concerning its initial rate and by an exponential function under in vivo conditions, in vitro-phagocytosis was phenomenologically described as an analogon of an irreversible bimolecular chemical reaction. In this way, rate and capacity of phagocytosis may be quantified separately. On the basis of systematic deviations of the data from this model, modifications have been developed which could be connected with pertinent observations. The design of further experiments from preliminary results on the basis of our models is discussed.

The influence of selected urinary constituents on the adhesion process of Escherichia coli to human uroepithelial cells

In the pathogenesis of infectious diseases, great importance is attached to the problem of adhesion of bacteria to cells. In 100 urine specimens from normal test persons, patients with infections of the lower urinary tract, with chronic pyelonephritis and glomerulonephritis were studied. The adhesion of strains of Escherichia coli to human uroepithelial cells depended on the concentration of single urinary factors. While increased concentrations of urea and creatinine favored the adhesion process, a statistically significant negative influence was found with regard to potassium, immunoglobulins and pH value. Considering the multifactorial effects of the urinary constituents, we found in a multivariate comparison that none of the studied physiological features alone exerts a fundamental influence upon adhesion, but in their entirety they determine the environmental conditions for the adhesion of bacteria to cells in the urine.