From cradle to grave? A global hotspot and new species of the genus Lobaria discovered in the Himalayas and the Hengduan Mountains.

In this study, the East Asian diversity of green-algal Lobaria was evaluated by applying both morphological and phylogenetic approaches. A multi-locus phylogenetic analysis of 72 green-algal Lobaria specimens was performed using a three-locus and time-calibrated species-tree approach. The analyses demonstrate that pairs of sexually and vegetatively reproducing lineages split into highly supported monophyletic clades. Taxonomically, 11 green-algal Lobaria species were identified as new to science, while 10 were previously described species. The species differentiated during the Pliocene and Pleistocene. The coincidence of paleoclimatic events with estimated dates of divergence support a bioclimatic hypothesis for species evolution in the green-algal Lobaria. Molecular phylogenies, a summary of diversity, detailed new species descriptions and geographical analyses are provided. Special recognition of species with a long evolutionary history, which merit high conservation priority, will be critical for preserving geographically restricted endemics in the Himalayas and the Hengduan Mountains, where habitat loss is driving rapid declines.

Evaluating methodologies for species delimitation: the mismatch between phenotypes and genotypes in lichenized fungi (Bryoria sect. Implexae, Parmeliaceae).

In many lichen-forming fungi, molecular phylogenetic analyses lead to the discovery of cryptic species within traditional morphospecies. However, in some cases, molecular sequence data also questions the separation of phenotypically characterised species. Here we apply an integrative taxonomy approach - including morphological, chemical, molecular, and distributional characters - to re-assess species boundaries in a traditionally speciose group of hair lichens, Bryoria sect. Implexae. We sampled multilocus sequence and microsatellite data from 142 specimens from a broad intercontinental distribution. Molecular data included DNA sequences of the standard fungal markers ITS, IGS, GAPDH, two newly tested loci (FRBi15 and FRBi16), and SSR frequencies from 18 microsatellite markers. Datasets were analysed with Bayesian and maximum likelihood phylogenetic reconstruction, phenogram reconstruction, STRUCTURE Bayesian clustering, principal coordinate analysis, haplotype network, and several different species delimitation analyses (ABGD, PTP, GMYC, and DISSECT). Additionally, past population demography and divergence times are estimated. The different approaches to species recognition do not support the monophyly of the 11 currently accepted morphospecies, and rather suggest the reduction of these to four phylogenetic species. Moreover, three of these are relatively recent in origin and cryptic, including phenotypically and chemically variable specimens. Issues regarding the integration of an evolutionary perspective into taxonomic conclusions in species complexes, which have undergone recent diversification, are discussed. The four accepted species, all epitypified by sequenced material, are Bryoria fuscescens, B. glabra, B. kockiana, and B. pseudofuscescens. Ten species rank names are reduced to synonymy. In the absence of molecular data, they can be recorded as the B. fuscescens complex. Intraspecific phenotype plasticity and factors affecting the speciation of different morphospecies in this group of Bryoria are outlined.

Vertical and horizontal photobiont transmission within populations of a lichen symbiosis.

Lichens are widespread symbioses and play important roles in many terrestrial ecosystems. The genetic structure of lichens is the result of the association between fungal and algal populations constituting the lichen thallus. Using eight fungus- and seven alga-specific highly variable microsatellite markers on within-population spatial genetic data from 62 replicate populations across Europe, North America, Asia and Africa, we investigated the contributions of vertical and horizontal transmission of the photobiont to the genetic structure of the epiphytic lichen Lobaria pulmonaria. Based on pairwise comparisons of multilocus genotypes defined separately for the mycobiont and for the photobiont, we inferred the transmission mode of the photobiont and the relative contribution of somatic mutation and recombination. After constraining the analysis of one symbiont to pairs of individuals with genetically identical symbiotic partners, we found that 77% of fungal and 70% of algal pairs were represented by clones. Thus, the predominant dispersal mode was by means of symbiotic vegetative propagules (vertical transmission), which dispersed fungal and algal clones co-dependently over a short distance, thus shaping the spatial genetic structure up to distances of 20m. Evidence for somatic mutation generating genetic diversity was found in both symbionts, accounting for 30% of pairwise comparisons in the alga and 15% in the fungus. While the alga did not show statistically significant evidence of recombination, recombination accounted for 7.7% of fungal pairs with identical algae. This implies that, even in a mostly vegetatively reproducing species, horizontal transmission plays a role in shaping the symbiotic association, as shown in many coral and other symbioses in nature.

Eradication of an epidemic methicillin-resistant Staphylococcus aureus (MRSA) from a geriatric university hospital: evidence from a 10-year follow-up.

We report on a successful eradication of methicillin-resistant S. aureus (MRSA) after an epidemic in 1992 in the geriatric ward of a tertiary-care hospital. After identification of MRSA in seven patients, all patients and staff members in the geriatric ward underwent screening. A multifaceted intervention plan was implemented: contact isolation, optimization of infection control and decolonization of all MRSA carriers. Thirty-two patients and five staff members were found to be MRSA carriers. Twenty one of 32 (66%) patients and all five staff members were successfully decolonized. Seven of 32 (22%) patients died during the epidemic before decolonization. A couple was discharged with persisting MRSA colonization and two individuals were lost to follow-up. The eradication of the epidemic clone was proven by systematic screenings in 1995 and 1997. Since then, the strain has no longer been identified in our institution, based on epidemiological surveillance and molecular typing of all MRSA strains obtained from any specimen. This study provides strong evidence that long-term eradication of an MRSA epidemic in a hospital is feasible, and endemicity of MRSA after an outbreak can be avoided. The successful bundle approach for eradication of MRSA during an epidemic is expensive, but the long-term benefits likely outweigh the initial heavy use of resources.

A species-specific real-time PCR assay for identification of three lichen-forming fungi, Lobaria pulmonaria, Lobaria immixta and Lobaria macaronesica.

We present a multiplex real-time PCR assay for the simultaneous identification of three morphologically similar species of lichen-forming fungi, Lobaria pulmonaria, Lobaria immixta and Lobaria macaronesica. Based on TaqMan MGB (minor groove binding) probes targeting the fungal internal transcribed spacer (ITS nrDNA) region, our assay unambiguously identifies known samples from all the three species, thus providing a powerful alternative to the more expensive DNA-sequencing techniques.

Recombination and clonal propagation in different populations of the lichen Lobaria pulmonaria.

Propagation, dispersal, and establishment are fundamental population processes, and are critical stages in the life cycle of an organism. In symbiotic organisms such as lichens, consisting of a fungus and a population of photobionts, reproduction is a complex process. Although many lichens are able to reproduce both sexually and asexually, the extent of vegetative propagation within local populations is unknown. We used six polymorphic microsatellite loci to investigate whether recombination is common in natural populations, and to assess if and how clonal reproduction influences the spatial genetic structure within populations of the epiphytic lichen species Lobaria pulmonaria. High genetic diversity within all 12 investigated populations and evidence of recombination, from various tests, indicated that L. pulmonaria is a predominantly outcrossing species. Nevertheless, clonality occurred in all populations, but the presence of recurring multilocus genotypes influenced the spatial genetic structure only within low-density populations. This could be interpreted as indicative of genetic bottlenecks owing to increased habitat loss and disturbance. Consequently, for a predominantly outcrossing lichen species, exogenous factors might be substantially altering population processes and hence genetic structure.

Regulation of cell expansion by the DISTORTED genes in Arabidopsis thaliana: actin controls the spatial organization of microtubules.

The control of the directionality of cell expansion was investigated using a class of eight genes, the so-called DISTORTED (DIS) genes, that are required for proper expansion of leaf trichomes in Arabidopsis thaliana. By tracing the separation of latex beads placed on the trichome surface, we demonstrate that trichomes grow by diffuse rather than tip growth, and that in dis mutants deviations from the normal orientation of growth can occur in all possible directions. We could not detect any differences in intracellular organization between wild-type and dis-group mutants by electron microscopy. The analysis of double mutants showed that although the expression of the dis phenotype is generally independent of branching and endoreduplication, dis mutations act synthetically in combination lesions in the ZWI gene, which encodes a kinesin motor protein. Using a MAP4:GFP marker line, we show that the organization of cortical microtubules is affected in dis-group mutants. The finding that most dis-group mutants have actin defects suggested to us that actin is involved in organizing the orientation of microtubules. By analyzing the microtubule organization in plants treated with drugs that bind to actin, we verified that actin is involved in the positioning of cortical microtubules and thereby in plant cell expansion.

Species-specific detection of Lobaria pulmonaria (lichenized ascomycete) diaspores in litter samples trapped in snow cover.

The foliose lichen Lobaria pulmonaria has suffered a substantial decline in central and northern Europe during the twentieth century and is now considered to be critically endangered in many European lowland regions. Based on demographic studies, it has been proposed that under the present environmental conditions and forest management regimes, dispersal of diaspores and subsequent establishment of new thalli are insufficient to maintain the remnant small lowland populations. Chances of long-term survival may therefore be reduced. The data and analytical power of these demographic studies are limited. Since lichen diaspores show very few species-specific morphological characteristics, and are therefore almost indistinguishable, the accurate assessment of diaspore flux would be a fundamental first step in better understanding the life cycle of L. pulmonaria. Here we present a new molecular approach to investigate the dispersal of L. pulmonaria diaspores in its natural environment by specifically identifying small amounts of DNA in snow litter samples at varying distances from known sources. We used a species-specific polymerase chain reaction (PCR) primer pair to amplify the ribosomal internal transcribed spacer region (ITS rDNA) and a sensitive automated PCR product detection system using fluorescent labelled primers. We detected considerable amounts of naturally dispersed diaspores, deposited as far as 50 m away from the closest potential source. Diaspores were only found in the direction of the prevailing wind. Diaspore deposition varied from 1.2 diaspores per m(2) per day at 50 m distance from the source to 15 diaspores per m(2) per day at 1 m distance. The method described in this paper opens up perspectives for studies of population dynamics and dispersal ecology mainly in lichenized ascomycetes but also in other organisms with small, wind-dispersed diaspores.

[Cold agglutinins of the IgM class in a patient with monoclonal gammopathy of the IgA class]. / Kälteagglutinine der IgM-Klasse bei einem Patienten mit monoklonaler Gammopathie der IgA-Klasse.

HISTORY AND CLINICAL PRESENTATION: A 61-year-old patient was examined in hospital because he had suffered from fatigue and weight loss for several years. History and physical examination showed no symptoms specific for a disease of a particular organ except a goitre. INVESTIGATIONS: Laboratory examination serum showed a decreased haptoglobin, a slightly elevated bilirubin, an acceleration of the blood sedimentation rate and a M-gradient in the protein electrophoresis. The immunofixation electrophoresis revealed a monoclonal gammopathy of the IgA-class. The cold agglutinin titre was clearly elevated (2048 at 4 degrees C), caused by an auto-anti-I of the IgM-class. No signs of an infection or a haematological neoplasm were found. TREATMENT AND COURSE: No specific therapy was given for the compensated haemolytic anaemia and the monoclonal gammopathy. There was no significant change in the course of the disease over 5 years. CONCLUSION: Between the specificity and the immunoglobulin class of cold agglutinins correlations exist that are also of significance for these autoantibodies. As shown by this case, an exact analysis of the specificity and the immunoglobulin class of cold agglutinins should be done in cases with unusual combinations of laboratory results to prevent misleading interpretations.

Genetic variation within and among populations of the threatened lichen Lobaria pulmonaria in Switzerland and implications for its conservation.

The foliose epiphytic lichen Lobaria pulmonaria has suffered a significant decline in European lowlands during the last decades and therefore is considered as endangered throughout Europe. An assessment of the genetic variability is necessary to formulate biologically sound conservation recommendations for this species. We investigated the genetic diversity of the fungal symbiont of L. pulmonaria using 143 specimens sampled from six populations (two small, one medium, three large) in the lowland, the Jura Mountains, the pre-Alps and the Alps of Switzerland. Among all nuclear and mitochondrial regions sequenced for this study, variability was found only in the internal transcribed spacer (ITS I), with three polymorphic sites, and in the nuclear ribosomal large subunit (nrLSU), with four polymorphic sites. The variable sites in the nrLSU are all located within a putative spliceosomal intron. We sequenced these two regions for 81 specimens and detected six genotypes. Two genotypes were common, two were found only in the more diverse populations and two were found only in one population each. There was no correlation between population size and genetic diversity. The highest genetic diversity was found in populations where the fungal symbiont is reproducing sexually. Populations with low genetic diversity included only the two same common genotypes. Our study provides evidence suggesting that L. pulmonaria is self-incompatible and heterothallic. Based on our results we give populations with sexually reproducing individuals a higher rank in terms of conservation priority than strictly asexual populations. The remaining lowland populations are so small, that one single catastrophic event such as a windthrow might destroy the entire population. Hence we suggest augmenting such populations in size and genetic diversity using small thallus fragments or vegetative diaspores collected in other populations. As we did not detect any locally adapted genotypes, these transplants can be taken from any other genetically diverse population in Switzerland.

HIV-related non-Hodgkin's lymphoma: CHOP induction therapy and interferon-alpha-2b/zidovudine maintenance therapy.

In a prospective multicenter study 68 out of 158 patients with HIV infection and malignant lymphoma were assigned to a risk-adapted induction therapy using the following algorithm: High-risk patients fulfilled 2 of 3 criteria: T4 lymphocytes <50/microL; WHO activity index 3 or 4; pre-existing AIDS-defining opportunistic infection. Normal-risk patients received 4 to 6 cycles of CHOP chemotherapy; those that achieved complete remission (CR) received zidovudine (500 mg/d) and interferon-alpha maintenance therapy (5 million units three times a week) for one year. High-risk patients received low-dose CHOP or vincristine/prednisone chemotherapy. Supportive care was performed with pentamidine inhalation and G-CSF. Intrathecal (it) methotrexate was given for CNS prophylaxis. The median survival was 634 days for 38 patients of the normal-risk group and 129 days for 30 patients of the high-risk group. 18 high-risk patients treated with low-dose CHOP had better survival (156 days) than 12 patients treated with vincristine/prednisone (72 days p=0.044). 68% of the patients in the normal-risk group achieved complete remission. 5 out of 18 high-risk patients treated with low-dose CHOP achieved complete remission. Three normal-risk patients developed fatal opportunistic infections during chemotherapy. Immune parameters deteriorated after CHOP induction and partially recovered with maintenance treatment. We conclude that the normal-risk patients survived longer than reported in most published studies. Toxicity was low. Low-dose CHOP seems to be superior to vincristine/prednisone therapy in high-risk patients.

Incidence and spectrum of severe medical complications among hospitalized HIV-seronegative and HIV-seropositive narcotic drug users.

OBJECTIVE: To examine differences in the incidence and spectrum of diseases, as well as duration of inpatient stay, between HIV-seronegative and HIV-seropositive narcotic drug, users (NDU). DESIGN: Retrospective analysis of 9 years of experience. Data collection by chart review using preset criteria for diagnoses. Estimation of hospital admission densities by assuming a dynamic but stable population of 2000 NDU (with a mean HIV-seroprevalence of 25%) throughout the study period. PATIENTS: Comprising 314 HIV-seronegative NDU. 217 HIV-seropositive NDU, and 10 NDU with admissions registered in either group (from a total of 1011 admissions). RESULTS: The overall admission incidence density was 35 and 120 per 1000 person-years among HIV-seronegative NDU and HIV-seropositive NDU, respectively [risk ratio (RR) 3.5, 95% confidence interval (CI) 3.2-3.7]. Compared with seronegative NDU, HIV-seropositive NDU were more frequently admitted for various non-opportunistic infections (RR 7.2, 95% CI 6.1-8.4), including pneumonia (RR 10.9, 95% CI 7.6-16.6), tuberculosis (RR 30.0, 95% CI 3.6-233.8), soft-tissue infections (RR 3.5, 95% CI 1.7-7.2), osteoarticular infections (RR 6.0, 95% CI 1.5-23.9), endocarditis (RR 5.3, 95% CI 1.5-17.9), and various other infections (RR 5.8, 95% CI 3.2-10.5). HIV-seropositive NDU were also more frequently admitted for non-infectious medical complications (RR 2.3, 95% CI 1.8-3.0). Seronegative NDU had a shorter median inpatient stay (2 versus 9 days, P < 0.00001). HIV infection accounted for an estimated excess burden of at least 2700 inpatient care days in 9 years among the 500 local HIV-seropositive NDU. CONCLUSIONS: Among NDU, HIV infection adds considerable excess burden in terms of severe complications needing inpatient care.

Effects of ozone fumigation on epiphytic macrolichens: ultrastructure, CO2 gas exchange and chlorophyll fluorescence.

The lichen species Anaptychia ciliaris, Collema nigrescens, Evernia prunastri, Hypogymnia bitteri, Lobaria pulmonaria, Pseudevernia furfuracea and Usnea rigida s.l. were fumigated with site-relevant concentrations (for Central Europe) of ozone over 80 days (180 microg m(-3) during daytime, 80 microg m(-3) during the night). Chlorophyll fluorescence measurements revealed a significant reduction of Fv/Fm after ozone fumigation in five of the species investigated, indicating severe stress on photosystem II due to ozone. The physiological impairment paralleled our fine structural investigations, revealing a significantly higher percentage of collapsed photobiont cells. This indicates that the effects of ambient ozone concentrations under experimental conditions included biophysical and physiological, as well as structural impairment in the lichens studied.

[HIV-associated lymphomas]. / HIV-assoziierte Lymphome.

Forty-one HIV-positive homosexual men (mean age 39.8 [23-72] years) with malignant lymphomas were examined with the object of exploring the clinical and pathological spectrum of HIV-associated lymphomas in Central Europe, and their therapeutic aspects. There were 33 patients with non-Hodgkin lymphoma of high malignancy and four with non-Hodgkin lymphoma of low malignancy; four further patients suffered from Hodgkin's disease. 27 patients died during the period of observation. The mean survival period after diagnosis was 5.5 months. It depended on the stage reached by the lymphoma at the time of diagnosis: 11.8 months in stage I, 10.6 months in stage II, 7 months in stage III, 3.3 months in stage IV and 1.3 months in patients with primary involvement of the central nervous system by the lymphoma. Eight out of nine patients with highly malignant non-Hodgkin lymphoma in stage I or II attained complete and lasting remissions after chemotherapy or irradiation. However, only minimal prolongation of life was achieved in the 16 patients with lymphomas in stages III or IV. The response rate among all patients treated (complete and partial remissions) was 75%; 45% achieved complete remission. Hodgkin's disease responded well to standard therapy, but the disease rapidly recurred in every case.

Humoral immune response to pneumococcal antigen 23-F in an asplenic patient with recurrent fulminant pneumococcaemia.

Host defence mechanisms were analysed in a patient with three episodes of fulminant pneumococcaemia and one episode of bacteraemic epiglottitis with Haemophilus influenzae type b. The first episode took place 11 years after splenectomy for blunt abdominal trauma. Investigations revealed several host defence mechanisms to be impaired. In addition to the patient's asplenia, an inherited C2-deficiency was noted. Assessment of IgG subclasses repeatedly revealed markedly low IgG4 concentrations. These were not due to an increased turnover of IgG4, as could be shown following infusion of intravenous IgG. In addition, IgG2 concentrations were low in the patient who lacked G2M(23). Opsonic mediating antibodies against type 23-F pneumococci were in the range of those of non-immune volunteers 6 months after vaccination with a 23-valent pneumococcal vaccine. These antibodies did not increase after a septic episode with 23-F capsular-type pneumococci. Neutrophil function was apparently normal.