Public-health and individual approaches to antiretroviral therapy: township South Africa and Switzerland compared

Background

The provision of highly active antiretroviral therapy (HAART) in resource-limited settings follows a public health approach, which is characterised by a limited number of regimens and the standardisation of clinical and laboratory monitoring. In industrialized countries doctors prescribe from the full range of available antiretroviral drugs, supported by resistance testing and frequent laboratory monitoring. We compared virologic response, changes to first-line regimens, and mortality in HIV-infected patients starting HAART in South Africa and Switzerland.

Methods and Findings

We analysed data from the Swiss HIV Cohort Study and two HAART programmes in townships of Cape Town, South Africa. We included treatment-naïve patients aged 16 y or older who had started treatment with at least three drugs since 2001, and excluded intravenous drug users. Data from a total of 2,348 patients from South Africa and 1,016 patients from the Swiss HIV Cohort Study were analysed. Median baseline CD4⁺ T cell counts were 80 cells/μl in South Africa and 204 cells/μl in Switzerland. In South Africa, patients started with one of four first-line regimens, which was subsequently changed in 514 patients (22%). In Switzerland, 36 first-line regimens were used initially, and these were changed in 539 patients (53%). In most patients HIV-1 RNA was suppressed to 500 copies/ml or less within one year: 96% (95% confidence interval [CI] 95%–97%) in South Africa and 96% (94%–97%) in Switzerland, and 26% (22%–29%) and 27% (24%–31%), respectively, developed viral rebound within two years. Mortality was higher in South Africa than in Switzerland during the first months of HAART: adjusted hazard ratios were 5.90 (95% CI 1.81–19.2) during months 1–3 and 1.77 (0.90–3.50) during months 4–24.

Conclusions

Compared to the highly individualised approach in Switzerland, programmatic HAART in South Africa resulted in similar virologic outcomes, with relatively few changes to initial regimens. Further innovation and resources are required in South Africa to both achieve more timely access to HAART and improve the prognosis of patients who start HAART with advanced disease.     

European common frog (Rana temporaria) recolonized Switzerland from multiple glacial refugia in northern Italy via trans‐ and circum‐Alpine routes

The high mountain ranges of Western Europe had a profound effect on the biotic recolonization of Europe from glacial refugia. The Alps present a particularly interesting case because they form an absolute barrier to dispersal for most taxa, obstructing recolonization from multiple refugia in northern Italy. Here, we investigate the effect of the European Alps on the phylogeographic history of the European common frog Rana temporaria. Based on partial cytochrome b and COXI sequences from Switzerland, we find two mitochondrial lineages roughly north and south of the Alpine ridge, with contact zones between them in eastern and western Switzerland. The northern haplogroup falls within the previously identified Western European haplogroup, while the southern haplogroup is unique to Switzerland. We find that the lineages diverged ~110 kya, at approximately the onset of the last glacial glaciation; this indicates that they are from different glacial refugia. Phylogenetic analyses suggest that the northern and southern haplogroups colonized Switzerland via trans‐ and circum‐Alpine routes from at least two separate refugia in northern Italy. Our results illustrate how a complex recolonization history of the central European Alps can arise from the semi‐permeable barrier created by high mountains.     

Tuberculosis in HIV-negative and HIV-infected patients in a low-incidence country: clinical characteristics and treatment outcomes

Background

In Switzerland and other developed countries, the number of tuberculosis (TB) cases has been decreasing for decades, but HIV-infected patients and migrants remain risk groups. The aim of this study was to compare characteristics of TB in HIV-negative and HIV-infected patients diagnosed in Switzerland, and between coinfected patients enrolled and not enrolled in the national Swiss HIV Cohort Study (SHCS).

Methods and Findings

All patients diagnosed with culture-confirmed TB in the SHCS and a random sample of culture-confirmed cases reported to the national TB registry 2000–2008 were included. Outcomes were assessed in HIV-infected patients and considered successful in case of cure or treatment completion. Ninety-three SHCS patients and 288 patients selected randomly from 4221 registered patients were analyzed. The registry sample included 10 (3.5%) coinfected patients not enrolled in the SHCS: the estimated number of HIV-infected patients not enrolled in the SHCS but reported to the registry 2000–2008 was 146 (95% CI 122–173). Coinfected patients were more likely to be from sub-Saharan Africa (51.5% versus 15.8%, P<0.0001) and to present disseminated disease (23.9% vs. 3.4%, P<0.0001) than HIV-negative patients. Coinfected patients not enrolled in the SHCS were asylum seekers or migrant workers, with lower CD4 cell counts at TB diagnosis (median CD4 count 79 cells/µL compared to 149 cells/µL among SHCS patients, P = 0.07). There were 6 patients (60.0%) with successful outcomes compared to 82 (88.2%) patients in the SHCS (P = 0.023).

Conclusions

The clinical presentation of coinfected patients differed from HIV-negative TB patients. The number of HIV-infected patients diagnosed with TB outside the SHCS is similar to the number diagnosed within the cohort but outcomes are poorer in patients not followed up in the national cohort. Special efforts are required to address the needs of this vulnerable population.     

Observations on Echinococcus granulosus of cattle origin in Switzerland

Switzerland is one of the few countries where high fertility rates have been reported in cattle hydatid cysts and where the cattle/dog cycle is the most important for the maintenance of Echinococcus granulosus. The developmental and morphological characteristics of E. granulosus of Swiss cattle origin were studied and compared with that of E. granulosus of domestic animal origin from Great Britain and Australia, countries where bovine hydatid cysts are usually sterile and cattle play little role in the life-cycle of the parasite. Adult E. granulosus of Swiss cattle origin differed markedly in its developmental characteristics compared to other isolates, particularly in its rate of maturation in dogs, producing eggs as early as 35 days post-infection. The morphology of E. granulosus of Swiss cattle origin was characteristic and it could be easily distinguished from other isolates of the parasite. Further, E. granulosus of Swiss cattle origin was found to closely resemble that occurring in cattle in South Africa where high fertility rates have also been reported in bovine hydatid cysts. It is concluded that a strain of E. granulosus exists which is adapted to cattle and that further studies are required to determine whether this strain warrants formal taxonomic status as the species E. ortleppi which was originally described for the parasite of South African cattle origin.     

Differences in the nestling begging calls of hosts and host-races of the common cuckoo, Cuculus canorus

We compared nestling begging calls of four hosts (reed warbler, Acrocephalus scirpaceus; great reed warbler, A. arundinaceus; dunnock, Prunella modularis; and meadow pipit, Anthus pratensis) and the respective host-races of the common cuckoo. Note structure varied between host species, but not between cuckoo host-races, so cuckoos did not vary their call note structure to match that of their hosts' chicks. Call rate increased with age, but there were marked differences between both host species and cuckoo host-races. Dunnock-cuckoos called more rapidly than reed warbler-cuckoos despite growing at the same rate. We suggest this difference reflects how cuckoos tune into the way these host species respond to begging signals from their own young, because dunnock chicks called much more rapidly than reed warbler chicks. Great reed warbler-cuckoos called at a lower rate than reed warbler-cuckoos when young, but at a greater rate when older than 8 days. This could also result from the cuckoo chicks tuning into differences in the way these hosts respond to begging signals. However, great reed warbler-cuckoos grew at a faster rate than the other cuckoo host-races, so they may also call faster to demand higher provisioning rates from this larger host. To test these hypotheses critically, data are needed on how the different host species integrate visual and vocal begging signals from their own broods. We discuss how differences in cuckoo begging might develop, given that cuckoo host-races are restricted to female cuckoo lineages. Copyright 2003 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.      

Reed warblers guard against cuckoos and cuckoldry

Previous studies have shown that reed warblers, Acrocephalus scirpaceus, are more likely to reject a cuckoo, Cuculus canorus, egg if they have seen a cuckoo at their nest. This suggests that they would benefit from watching out for cuckoos. We tested whether presentations of a cuckoo mount near the nest (to simulate nest inspection) led to increased nest attendance by the warblers. Cuckoo presentations at completed nests before laying, when males guarded their females closely, led to desertion at 40% of nests before any eggs were laid (there were no desertions after presentations of a jay,Garrulus glandarius , a nest predator). In the remaining cases, there was no effect of the cuckoo on nest attendance before laying began, but a marked increase in male nest attendance (compared with jay and no-presentation controls) on the days the first and second eggs were laid. Cuckoo presentations at the one-egg stage led to the same increase in male nest attendance as did the prelaying presentations. Increased male nest attendance at the one-two-egg stage was not at the expense of mate guarding, because this declined anyway when laying began, and it did not lead to increased paternity loss compared with controls. Overall, 15% of broods had one or two extrapair young (6% of all young extrapair). We conclude that male reed warblers do increase nest guarding in response to cuckoos, but only after their females have begun egg laying, when there are less likely to be costs in lost paternity. Females did not increase nest guarding, perhaps because they need to spend more time foraging during the egg-laying period. Our results suggest that cuckoos should be secretive not only when they lay but also when they monitor host nests beforehand. Copyright 2003 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.      

IFN-�� signaling, with the synergistic contribution of TNF-��, mediates cell specific microglial and astroglial activation in experimental models of Parkinson's disease

To through light on the mechanisms underlying the stimulation and persistence of glial cell activation in Parkinsonism, we investigate the function of IFN-γ and TNF-α in experimental models of Parkinson''s disease and analyze their relation with local glial cell activation. It was found that IFN-γ and TNF-α remained higher over the years in the serum and CNS of chronic Parkinsonian macaques than in untreated animals, accompanied by sustained glial activation (microglia and astroglia) in the substantia nigra pars compacta. Importantly, Parkinsonian monkeys showed persistent and increasing levels of IFN-γR signaling in both microglial and astroglial cells. In addition, experiments performed in IFN-γ and TNF-α KO mice treated with MPTP revealed that, even before dopaminergic cell death can be observed, the presence of IFN-γ and TNF-α is crucial for microglial and astroglial activation, and, together, they have an important synergistic role. Both cytokines were necessary for the full level of activation to be attained in both microglial and astroglial cells. These results demonstrate that IFN-γ signaling, together with the contribution of TNF-α, have a critical and cell-specific role in stimulating and maintaining glial cell activation in Parkinsonism.     

Leishmania mexicana metacaspase is a negative regulator of amastigote proliferation in mammalian cells

Metacaspases (MCAs) are caspase family cysteine peptidases that have been implicated in cell death processes in plants, fungi and protozoa. MCAs have also been suggested to be involved in cell cycle control, differentiation and clearance of aggregates; they are virulence factors. Dissecting the function of MCAs has been complicated by the presence in many organisms of multiple MCA genes or limitations on genetic manipulation. We describe here the creation of a MCA gene-deletion mutant (Δmca) in the protozoan parasite Leishmania mexicana, which has allowed us to dissect the role of the parasite''s single MCA gene in cell growth and cell death. Δmca parasites are viable as promastigotes, and differentiate normally to the amastigote form both in in vitro macrophages infection and in mice. Δmca promastigotes respond to cell death inducers such as the drug miltefosine and H₂O₂ similarly to wild-type (WT) promastigotes, suggesting that MCAs do not have a caspase-like role in execution of L. mexicana cell death. Δmca amastigotes replicated significantly faster than WT amastigotes in macrophages and in mice, but not as axenic culture in vitro. We propose that the Leishmania MCA acts as a negative regulator of amastigote proliferation, thereby acting to balance cell growth and cell death.     

AACR-ISREC joint symposium ‘Cancer and the cell cycle’ January 17–20, 1996, Laussnne,Switzerland

It has become apparent in the recent years that defects in regulatory systems of the eukaryotic cell cycle contribute, in a major way, to the evolution of a neoplastic phenotype in mammalian cells. The American Association of Cancer Research (AACR) and the Swiss Institute for Experimental Cancer Research (ISREC) jointly organized a meeting, held last January in Lausanne/Switzerland, to discuss recent results in cell cycle research and their implications for cancer.     

The process of reversible phosphorylation: the work of Edmond H. Fischer

Edmond H. Fischer was awarded the 1992 Nobel Prize in Physiology or Medicine for his joint research with Edwin G. Krebs on reversible protein phosphorylation. The two Classics reprinted here relate some of Fischer and Krebs'' early discoveries in their phosphorylase researchPhosphorylase Activity of Skeletal Muscle Extracts (Krebs, E. G., and Fischer, E. H. (1955) J. Biol. Chem. 216, 113–120)Conversion of Phosphorylase b to Phosphorylase a in Muscle Extracts (Fischer, E. H., and Krebs, E. G. (1955) J. Biol. Chem. 216, 121–132)Edmond H. Fischer was born in Shanghai, China in 1920. He was sent to boarding school in Switzerland at age 7, and in 1935, he entered Geneva''s Collège de Calvin. There, he became friends with his classmate Wilfried Haudenschild, and together, they decided that one of them should go into the sciences and the other into medicine so they could cure the world of all ills. Fischer chose science.Open in a separate windowEdmond H. FischerJust before the start of World War II, Fischer completed high school and entered the School of Chemistry at the University of Geneva. He earned two Licences ès Sciences, one in biology, the other in chemistry, and 2 years later, he was awarded a Diploma of “Ingénieur Chimiste.” For his thesis, he worked with Kurt H. Meyer on the purification of amylase from hog and human pancreas, as well as saliva and several strains of bacteria.In 1950, Fischer went to the United States to do a postdoctoral fellowship with Paul Karrer at CalTech. However, when he arrived in Pasadena he received a letter from Journal of Biological Chemistry (JBC) Classic author Hans Neurath (1), chairman of the department of biochemistry at the University of Washington, offering him an assistant professorship in his department. Fischer visited Seattle and accepted the offer, in part because the surrounding mountains, forests, and lakes reminded him of his native Switzerland.Within 6 months of his arrival, Fischer started working on glycogen phosphorylase with Edwin G. Krebs, who was featured in a previous JBC Classic (2). Krebs had trained with JBC Classic authors Carl and Gerty Cori who had discovered that muscle phosphorylase exists in two forms, phosphorylase a, which was easily crystallized and was active without the addition of AMP, and phosphorylase b, a more soluble protein, which was inactive without AMP (3). They believed that AMP served some kind of co-factor function for the enzyme, facilitating its transition between the two forms.However, in Geneva, Fischer had purified potato phosphorylase, which had no AMP requirement. Because it seemed unlikely that muscle phosphorylase but not potato phosphorylase would require AMP as a co-factor, Fischer and Krebs decided to try to elucidate the role of AMP in the phosphorylase reaction. They never discovered what the nucleotide was doing (this problem was solved several years later when Jacques Monod proposed his allosteric model for the regulation of enzymes), but they did discover that muscle phosphorylase was regulated by an enzyme-catalyzed phosphorylation-dephosphorylation reaction.The two JBC Classics reprinted here relate some of Fischer and Krebs'' early discoveries in their phosphorylase research. In the first Classic, the pair performed experiments to determine whether environmental temperature affects the phosphorylase content of skeletal muscle. They were unable to detect any temperature effects, but they did make the surprising discovery that the muscle extracts contained mainly phosphorylase b rather than phosphorylase a. The pair concluded that “If resting muscle contains mainly phosphorylase b… then pronounced activation of the phosphorylase reaction under various conditions is possible.”The second JBC Classic was printed back-to-back with the first. In it, Krebs and Fischer examine the requirements for the phosphorylase conversion and present evidence that the conversion of phosphorylase b to a in cell-free muscle extracts requires a nucleotide containing high energy phosphate and a divalent metal ion. However, they state that “whether this implies that during conversion there is a direct phosphorylation of the enzyme or the formation of an ‘active’ intermediate cannot be stated at this time. It is also possible that the function of ATP is concerned with the synthesis of a prosthetic group.”Similar work was being carried out on liver phosphorylase at approximately the same time by Earl Sutherland. As discussed in a previous JBC Classic (4), Sutherland discovered the second messenger cyclic AMP (cAMP), which he showed promoted the phosphorylation and activation of phosphorylase. The way in which cAMP promoted phosphorylase activation was eventually elucidated when Krebs and Fischer discovered phosphorylase kinase, which was responsible for phosphorylating phosphorylase. Phosphorylase kinase itself existed in a highly activated phosphorylated form and a less active nonphosphorylated form.As a result of the significance of their studies, Krebs and Fischer were awarded the 1992 Nobel Prize in Physiology or Medicine “for their discoveries concerning reversible protein phosphorylation as a biological regulatory mechanism.”In addition to the Nobel Prize, Fischer has received many awards and honors in recognition of his contributions to science. These include the Werner Medal from the Swiss Chemical Society, the Lederle Medical Faculty Award, the Prix Jaubert from the University of Geneva, and jointly with Krebs, the Senior Passano Award and the Steven C. Beering Award from Indiana University. Fischer was elected to the American Academy of Arts and Sciences in 1972 and to the National Academy of Sciences in 1973.¹     

Specificity of calcium/calmodulin-dependent protein kinases in mouse egg activation

CaMKIIγ, the predominant CaMKII isoform in mouse eggs, controls egg activation by regulating cell cycle resumption. In this study we further characterize the involvement and specificity of CaMKIIγ in mouse egg activation. Using exogenous expression of different cRNAs in Camk2g^−/− eggs, we show that the other multifunctional CaM kinases, CaMKI, and CaMKIV, are not capable of substituting CaMKIIγ to initiate cell cycle resumption in response to a rise in intracellular Ca²⁺. Exogenous expression of Camk2g or Camk2d results in activation of nearly 80% of Camk2g^−/− MII eggs after stimulation with SrCl₂, which does not differ from the incidence of activation of wild-type eggs expressing exogenous Egfp. In contrast, none of the Camk2g^−/− MII eggs expressing Camk1 or Camk4 activate in response to SrCl₂ treatment. Expression of a constitutively active form of Camk4 (ca-Camk4), but not Camk1, triggers egg activation. EMI2, an APC/C repressor, is a key component in regulating egg activation downstream of CaMKII in both Xenopus laevis and mouse. We show that exogenous expression of either Camk2g, Camk2d, or ca-Camk4, but not Camk1, Camk4, or a catalytically inactive mutant form of CaMKIIγ (kinase-dead) in Camk2g^−/− mouse eggs leads to almost complete degradation (~90%) of exogenously expressed EMI2 followed by cell cycle resumption. Thus, degradation of EMI2 following its phosphorylation specifically by CaMKII is mechanistically linked to and promotes cell cycle resumption in MII eggs.     

Genetic Control of the Cell Division Cycle in Yeast: V. Genetic Analysis of cdc Mutants

One hundred and forty-eight temperature-sensitive cell division cycle (cdc) mutants of Saccharomyces cerevisiae have been isolated and characterized. Complementation studies ordered these recessive mutations into 32 groups and tetrad analysis revealed that each of these groups defines a single nuclear gene. Fourteen of these genes have been located on the yeast genetic map. Functionally related cistrons are not tightly clustered.

Mutations in different cistrons frequently produce different cellular and nuclear morphologies in the mutant cells following incubation at the restrictive temperature, but all the mutations in the same cistron produce essentially the same morphology. The products of these genes appear, therefore, each to function individually in a discrete step of the cell cycle and they define collectively a large number of different steps.

The mutants were examined by time-lapse photomicroscopy to determine the number of cell cycles completed at the restrictive temperature before arrest. For most mutants, cells early in the cell cycle at the time of the temperature shift (before the execution point) arrest in the first cell cycle while those later in the cycle (after the execution point) arrest in the second cell cycle. Execution points for allelic mutations that exhibit first or second cycle arrest are rather similar and appear to be cistron-specific. Other mutants traverse several cycles before arrest, and its suggested that the latter type of response may reveal gene products that are temperature-sensitive for synthesis, whereas the former may be temperature-sensitive for function.

The gene products that are defined by the cdc cistrons are essential for the completion of the cell cycle in haploids of a and α mating type and in a/α diploid cells. The same genes, therefore, control the cell cycle in each of these stages of the life cycle.

     

Modelling the Expansion of a Grey Squirrel population: Implications for Squirrel Control

A recently discovered population of the North American grey squirrel (Sciurus carolinensis), introduced to Ticino Park, Lombardy (N Italy), is likely to spread into continuous prealpine broadleaf forests of Lombardy and the south of Switzerland. We used Spatially Explicit Population Dynamics Models (SEPMs), successfully used to predict the spread of grey squirrels in England and Piedmont, Italy, to examine the effects of different control scenarios on grey squirrel expansion in a 20000 km² area around Ticino Park. Without control, grey squirrels will invade Switzerland within the next two decades, and, concomitantly, the size and distribution of local populations of native red squirrels will be reduced. Simulating different grey squirrel control or removal scenarios suggests that: (i) efficient control is possible and mainly determined by the spatial distribution and woodland size of the ‘target’ control areas; and (ii) immediate actions must be taken, since delay in grey squirrel control will result in the population increasing and spreading, which makes the problems of successful containment more difficult. Model scenarios were based on surveys that may underestimate the real distribution range and current population size of grey squirrels. Therefore, a combination of hair–tube monitoring and a public participation survey to detect grey squirrel presence, which may also help to increase public awareness, is recommended. Successful containment of further grey squirrel spread will require local co-operation between Italian and Swiss authorities involved in wildlife management.     

Drought-adaptation potential in Fagus sylvatica: linking moisture availability with genetic diversity and dendrochronology

Background

Microevolution is essential for species persistence especially under anticipated climate change scenarios. Species distribution projection models suggested that the dominant tree species of lowland forests in Switzerland, European beech (Fagus sylvatica L.), might disappear from most areas due to expected longer dry periods. However, if genotypes at the moisture boundary of the species climatic envelope are adapted to lower moisture availability, they can serve as seed source for the continuation of beech forests under changing climates.

Methodology/Principal Findings

With an AFLP genome scan approach, we studied neutral and potentially adaptive genetic variation in Fagus sylvatica in three regions containing a dry and a mesic site each (n _ind. = 241, n _markers = 517). We linked this dataset with dendrochronological growth measures and local moisture availabilities based on precipitation and soil characteristics. Genetic diversity decreased slightly at dry sites. Overall genetic differentiation was low (F _st = 0.028) and Bayesian cluster analysis grouped all populations together suggesting high (historical) gene flow. The Bayesian outlier analyses indicated 13 markers with three markers differing between all dry and mesic sites and the others between the contrasting sites within individual regions. A total of 41 markers, including seven outlier loci, changed their frequency with local moisture availability. Tree height and median basal growth increments were reduced at dry sites, but marker presence/absence was not related to dendrochronological characteristics.

Conclusion and Their Significance

The outlier alleles and the makers with changing frequencies in relation to moisture availability indicate microevolutionary processes occurring within short geographic distances. The general genetic similarity among sites suggests that ‘preadaptive’ genes can easily spread across the landscape. Yet, due to the long live span of trees, fostering saplings originating from dry sites and grown within mesic sites might increase resistance of beech forests during the anticipated longer dry periods.     

Mitotic defects lead to pervasive aneuploidy and accompany loss of RB1 activity in mouse LmnaDhe dermal fibroblasts

Background

Lamin A (LMNA) is a component of the nuclear lamina and is mutated in several human diseases, including Emery-Dreifuss muscular dystrophy (EDMD; OMIM ID# 181350) and the premature aging syndrome Hutchinson-Gilford progeria syndrome (HGPS; OMIM ID# 176670). Cells from progeria patients exhibit cell cycle defects in both interphase and mitosis. Mouse models with loss of LMNA function have reduced Retinoblastoma protein (RB1) activity, leading to aberrant cell cycle control in interphase, but how mitosis is affected by LMNA is not well understood.

Results

We examined the cell cycle and structural phenotypes of cells from mice with the Lmna allele, Disheveled hair and ears (Lmna^Dhe). We found that dermal fibroblasts from heterozygous Lmna^Dhe (Lmna^Dhe/+) mice exhibit many phenotypes of human laminopathy cells. These include severe perturbations to the nuclear shape and lamina, increased DNA damage, and slow growth rates due to mitotic delay. Interestingly, Lmna^Dhe/+ fibroblasts also had reduced levels of hypophosphorylated RB1 and the non-SMC condensin II-subunit D3 (NCAP-D3), a mitosis specific centromere condensin subunit that depends on RB1 activity. Mitotic check point control by mitotic arrest deficient-like 1 (MAD2L1) also was perturbed in Lmna^{Dhe /+} cells. Lmna^{Dhe /+} fibroblasts were consistently aneuploid and had higher levels of micronuclei and anaphase bridges than normal fibroblasts, consistent with chromosome segregation defects.

Conclusions

These data indicate that RB1 may be a key regulator of cellular phenotype in laminopathy-related cells, and suggest that the effects of LMNA on RB1 include both interphase and mitotic cell cycle control.     

Estimating loss to follow-up in HIV-infected patients on antiretroviral therapy: the effect of the competing risk of death in Zambia and Switzerland

Background

Loss to follow-up (LTFU) is common in antiretroviral therapy (ART) programmes. Mortality is a competing risk (CR) for LTFU; however, it is often overlooked in cohort analyses. We examined how the CR of death affected LTFU estimates in Zambia and Switzerland.

Methods and Findings

HIV-infected patients aged ≥18 years who started ART 2004–2008 in observational cohorts in Zambia and Switzerland were included. We compared standard Kaplan-Meier curves with CR cumulative incidence. We calculated hazard ratios for LTFU across CD4 cell count strata using cause-specific Cox models, or Fine and Gray subdistribution models, adjusting for age, gender, body mass index and clinical stage. 89,339 patients from Zambia and 1,860 patients from Switzerland were included. 12,237 patients (13.7%) in Zambia and 129 patients (6.9%) in Switzerland were LTFU and 8,498 (9.5%) and 29 patients (1.6%), respectively, died. In Zambia, the probability of LTFU was overestimated in Kaplan-Meier curves: estimates at 3.5 years were 29.3% for patients starting ART with CD4 cells <100 cells/µl and 15.4% among patients starting with ≥350 cells/µL. The estimates from CR cumulative incidence were 22.9% and 13.6%, respectively. Little difference was found between naïve and CR analyses in Switzerland since only few patients died. The results from Cox and Fine and Gray models were similar: in Zambia the risk of loss to follow-up and death increased with decreasing CD4 counts at the start of ART, whereas in Switzerland there was a trend in the opposite direction, with patients with higher CD4 cell counts more likely to be lost to follow-up.

Conclusions

In ART programmes in low-income settings the competing risk of death can substantially bias standard analyses of LTFU. The CD4 cell count and other prognostic factors may be differentially associated with LTFU in low-income and high-income settings.     

Hepatitis E virus seroprevalence among blood donors in southwest Switzerland

Aim

The aim of this study was to determine the seroprevalence of Hepatitis E virus (HEV) among blood donors in southwest Switzerland.

Background

HEV is recognized as a food-borne disease in industrialized countries, transmitted mainly through pork meat. Cases of transmission through blood transfusion have also been reported. Recent studies have revealed seroprevalence rates of 13.5%, 16.6% and 20.6% among blood donors in England, France and Denmark, respectively.

Methods

We analyzed 550 consecutive blood donor samples collected in the region of Lausanne, canton of Vaud, Switzerland, for the presence of anti-HEV IgG, using the MP Diagnostics HEV ELISA kit. For each donor, we documented age, sex and alanine aminotransferase (ALT) value.

Results

The study panel was composed of 332 men (60.4%) and 218 women (39.6%). Overall, anti-HEV IgG was found in 27 of 550 samples (4.9%). The seroprevalence was 5.4% (18/332) in men and 4.1% (9/218) in women. The presence of anti-HEV IgG was not correlated with age, gender or ALT values. However, we observed a peak in seroprevalence of 5.3% in individuals aged 51 to 70 years old.

Conclusions

Compared with other European countries, HEV seroprevalence among blood donors in southwest Switzerland is low. The low seroprevalence may be explained by the sensitivity of commercial tests used and/or the strict regulation of animal and meat imports. Data regarding HEV prevalence in Swiss livestock are lacking and merit exploration.     

A non-redundant function of cyclin E1 in hematopoietic stem cells

A precise balance between quiescence and proliferation is crucial for the lifelong function of hematopoietic stem cells (HSCs). Cyclins E1 and E2 regulate exit from quiescence in fibroblasts, but their role in HSCs remains unknown. Here, we report a non-redundant role for cyclin E1 in mouse HSCs. A long-term culture-initiating cell (LTC-IC) assay indicated that the loss of cyclin E1, but not E2, compromised the colony-forming activity of primitive hematopoietic progenitors. Ccne1^−/− mice showed normal hematopoiesis in vivo under homeostatic conditions but a severe impairment following myeloablative stress induced by 5-fluorouracil (5-FU). Under these conditions, Ccne1^−/− HSCs were less efficient in entering the cell cycle, resulting in decreased hematopoiesis and reduced survival of mutant mice upon weekly 5-FU treatment. The role of cyclin E1 in homeostatic conditions became apparent in aged mice, where HSC quiescence was increased in Ccne1^−/− animals. On the other hand, loss of cyclin E1 provided HSCs with a competitive advantage in bone marrow serial transplantation assays, suggesting that a partial impairment of cell cycle entry may exert a protective role by preventing premature depletion of the HSC compartment. Our data support a role for cyclin E1 in controlling the exit from quiescence in HSCs. This activity, depending on the physiological context, can either jeopardize or protect the maintenance of hematopoiesis.     

In-Hospital Disease Burden of Sarcoidosis in Switzerland from 2002 to 2012

Sarcoidosis is a multisystem disease with an unpredictable and sometimes fatal course while the underlying pathomechanism is still unclear. Reasons of the increasing hospitalization rate and mortality in the United States remain in dispute but incriminated are a number of distinct comorbidities and risk factors as well as the application of more aggressive therapeutic agents. Studies reflecting the recent development in central Europe are lacking. Our aim was to investigate the recent mortality and hospitalization rates as well as the underlying comorbidities of hospitalized sarcoidosis patients in Switzerland. In this longitudinal, nested case-control study, a nation-wide database provided by the Swiss Federal Office for Statistics enclosing every hospital entry covering the years 2002–2012 (n = 15,627,573) was analyzed. There were 8,385 cases with a diagnosis of sarcoidosis representing 0.054% (8,385 / 15,627,573) of all hospitalizations in Switzerland. These cases were compared with age- and sex-matched controls without the diagnosis of sarcoidosis. Hospitalization and mortality rates in Switzerland remained stable over the observed time period. Comorbidity analysis revealed that sarcoidosis patients had significantly higher medication-related comorbidities compared to matched controls, probably due to systemic corticosteroids and immunosuppressive therapy. Sarcoidosis patients were also more frequently re-hospitalized (median annual hospitalization rate 0.28 [IQR 0.15-0.65] vs. 0.19 [IQR 0.13-0.36] per year; p < 0.001), had a longer hospital stay (6 [IQR 2-13] vs. 4 [IQR 1-8] days; p < 0.001), had more comorbidities (4 [IQR 2-7] vs. 2 [IQR 1-5]; p < 0.001), and had a significantly higher in-hospital mortality (2.6% [95% CI 2.3%-2.9%] vs. 1.8% [95% CI 1.5%-2.1%] (p < 0.001). A worse outcome was observed among sarcoidosis patients having co-occurrence of associated respiratory diseases. Moreover, age was an important risk factor for re-hospitalization.     

Low-Temperature Isolation of Disease-Suppressive Bacteria and Characterization of a Distinctive Group of Pseudomonads

The influence of environmental factors during isolation on the composition of potential biocontrol isolates is largely unknown. Bacterial isolates that efficiently suppressed wheat seedling blight caused by Fusarium culmorum were found by isolating psychrotrophic, root-associated bacteria and by screening them in a bioassay that mimicked field conditions. The impact of individual isolation factors on the disease-suppressive index (DSI) of almost 600 isolates was analyzed. The bacteria originated from 135 samples from 62 sites in Sweden and Switzerland. The isolation factors that increased the probability of finding isolates with high DSIs were sampling from arable land, Swiss origin of samples, and origination of isolates from plants belonging to the family Brassicaceae. The colony morphology of the isolates was characterized and compared to DSIs, which led to identification of a uniform morphological group containing 57 highly disease-suppressive isolates. Isolates in this group were identified as Pseudomonas sp.; they were fluorescent on King's medium B and had characteristic crystalline structures in their colonies. These isolates were morphologically similar to seven strains that had previously been selected for suppression of barley net blotch caused by Drechslera teres. Members of this morphological group grow at 1.5°C and produce an antifungal polyketide (2,3-deepoxy-2,3-didehydrorhizoxin [DDR]). They have similar two-dimensional polyacrylamide gel electrophoresis protein profiles, phenotypic characteristics, and in vitro inhibition spectra of pathogens. In summary, in this paper we describe some isolation factors that are important for obtaining disease-suppressive bacteria in our system, and we describe a novel group of biocontrol pseudomonads.