Complex Population Structure of Lyme Borreliosis Group Spirochete Borrelia garinii in Subarctic Eurasia

Borrelia garinii, a causative agent of Lyme borreliosis in Europe and Asia, is naturally maintained in marine and terrestrial enzootic cycles, which primarily involve birds, including seabirds and migratory passerines. These bird groups associate with, correspondingly, Ixodes uriae and Ixodes ricinus ticks, of which the latter species may bite and transmit the infection to humans. Studies of the overlap between these two natural cycles of B. garinii have been limited, in part due to the absence of representative collections of this spirochete's samples, as well as of the lack of reliable measure of the genetic heterogeneity of its strains. As a prerequisite for understanding the epidemiological correlates of the complex maintenance of B. garinii, the present study sought to assess the diversity and phylogenetic relationships of this species' strains from its natural hosts and patients with Lyme borreliosis from subarctic Eurasia. We used sequence typing of the partial rrs-rrl intergenic spacer (IGS) of archived and prospective samples of B. garinii from I. uriae ticks collected predominantly on Commander Islands in North Pacific, as well as on the islands in northern Sweden and arctic Norway. We also typed B. garinii samples from patients with Lyme borreliosis and I. ricinus ticks infesting migratory birds in southern Sweden, or found questing in selected sites on the islands in the Baltic Sea and Lithuania. Fifty-two (68%) of 77 B. garinii samples representing wide geographical range and associated with I. ricinus and infection of humans contributed 12 (60%) of total 20 identified IGS variants. In contrast, the remaining 25 (32%) samples recovered from I. uriae ticks from a few islands accounted for as many as 10 (50%) IGS types, suggesting greater local diversity of B. garinii maintained by seabirds and their ticks. Two IGS variants of the spirochete in common for both tick species were found in I. ricinus larvae from migratory birds, an indication that B. garinii strains are exchanged between different ecological niches. Notably, B. garinii variants associated with I. uriae ticks were found in each of the six clusters, representing two phylogenetic lineages of this species identified among the studied samples. Our findings suggest that B. garinii in subarctic Eurasia comprises two partially overlapping populations with different levels of genetic heterogeneity, presumably, due to distinctive selective pressures on the spirochete in its marine and terrestrial enzootic cycles

Mapping of hormones and cortisol responses in patients after Lyme neuroborreliosis

<p>Abstract</p> <p>Background</p> <p>Persistent symptoms after treatment for neuroborreliosis are common for reasons mainly unknown. These symptoms are often unspecific and could be caused by dysfunctions in endocrine systems, an issue that has not been previously addressed systematically. We therefore mapped hormone levels in patients with previous confirmed Lyme neuroborreliosis of different outcomes and compared them with a healthy control group.</p> <p>Methods</p> <p>Twenty patients of a retrospective cohort of patients treated for definite Lyme neuroborreliosis were recruited 2.3 to 3.7 years (median 2.7) after diagnosis, together with 23 healthy controls. Lyme neuroborreliosis patients were stratified into two groups according to a symptom/sign score. All participants underwent anthropometric and physiological investigation as well as an extensive biochemical endocrine investigation including a short high-dose adrenocorticotropic hormone stimulation (Synacthen^®) test. In addition to hormonal status, we also examined electrolytes, 25-hydroxy-vitamin D and interleukin-6.</p> <p>Results</p> <p>Eight patients (40%) had pronounced symptoms 2-3 years after treatment. This group had a higher cortisol response to synacthen as compared with both controls and the Lyme neuroborreliosis patients without remaining symptoms (p < 0.001 for both comparisons). No other significant differences in the various baseline biochemical parameters, anthropometric or physiological data could be detected across groups.</p> <p>Conclusions</p> <p>Apart from a positive association between the occurrence of long-lasting complaints after Lyme neuroborreliosis and cortisol response to synacthen, no corticotropic insufficiency or other serious hormonal dysfunction was found to be associated with remaining symptoms after treatment for Lyme neuroborreliosis.</p

The meaning of quality work from the general practitioner's perspective: an interview study

BACKGROUND: The quality of health care and its costs have been a subject of considerable attention and lively discussion. Various methods have been introduced to measure, assess, and improve the quality of health care. Many professionals in health care have criticized quality work and its methods as being unsuitable for health care. The aim of the study was to obtain a deeper understanding of the meaning of quality work from the general practitioner's perspective. METHODS: Fourteen general practitioners, seven women and seven men, were interviewed with the aid of a semi-structured interview guide about their experience of quality work. The interviews were tape-recorded and transcribed verbatim. Data collection and analysis were guided by a phenomenological approach intended to capture the essence of the statements. RESULTS: Two fundamentally different ways to view quality work emerged from the statements: A pronounced top-down perspective with elements of control, and an intra-profession or bottom-up perspective. From the top-down perspective, quality work was described as something that infringes professional freedom. From the bottom-up perspective the statements described quality work as a self-evident duty and as a professional attitude to the medical vocation, guided by the principles of medical ethics. Follow-up with a bottom-up approach is best done in internal processes, with the profession itself designing structures and methods based on its own needs. CONCLUSIONS: The study indicates that general practitioners view internal follow-up as a professional obligation but external control as an imposition. This opposition entails a difficulty in achieving systematism in follow-up and quality work in health care. If the statutory standards for systematic quality work are to gain a real foothold, they must be packaged in such a way that general practitioners feel that both perspectives can be reconciled

C6 peptide ELISA test in the serodiagnosis of Lyme borreliosis in Sweden

The aim of this study was to evaluate the synthetic C6 peptide test as a first-line test in a two-tiered scheme for Borrelia serology in a clinically well-characterized population of patients with Lyme borreliosis in Kalmar County, Sweden. The study population consisted of a prospective group (n=200), a control group (n=255), and a retrospective group (n=29). The test panel consisted of the Immunetics Quick ELISA C6 Borrelia assay kit (Immunetics, Cambridge, MA, USA), the Virotech Borrelia burgdorferi ELISA (Genzyme Virotech, Russelsheim, Germany), and the Liaison Borrelia CLIA (DiaSorin, Saluggia, Vercelli, Italy). Seroprevalence among 200 healthy blood donors was significantly lower in the C6 test (8%) compared to the Virotech ELISA (14%) and the Liaison CLIA (12%). In convalescent sera (2-3 months and 6 months post infection) from 158 patients with erythema migrans, the seropositivity in the C6 test was also significantly lower compared to both the Virotech ELISA and the Liaison CLIA. Serosensitivity in the acute phase of erythema migrans and other clinical manifestations of borreliosis did not differ significantly between the C6 test and the Virotech ELISA or the Liaison CLIA. Overall, a positive C6 test seems to correlate well with acute borreliosis. Cross-reactivity was lower in the C6 test in sera positive for Epstein-Barr virus infection as compared to the Virotech ELISA. This study supports the use of the C6 test as a screening test for borreliosis, in endemic areas

Pyruvate dehydrogenase kinase 1 is essential for transplantable mouse bone marrow hematopoietic stem cell and progenitor function.

BACKGROUND:Accumulating evidence suggests that hypoxic areas in the bone marrow are crucial for maintenance of hematopoietic stem cells (HSCs) by supporting a quiescent state of cell cycle and regulating the transplantation capacity of long-term (LT)-HSCs. In addition, HSCs seem to express a metabolic profile of energy production away from mitochondrial oxidative phosphorylation in favor of glycolysis. At oxygen deprivation, hypoxia inducible factor 1α (HIF-1α) is known to induce glycolytic enzymes as well as suppressing mitochondrial energy production by inducing pyruvate dehydrogenase kinase 1 (Pdk1) in most cell types. It has not been established whether PDK1 is essential for HSC function and mediates hypoxia-adapting functions in HSCs. While the Pdk gene family contains four members (Pdk1-4), it was recently shown that Pdk2 and Pdk4 have an important role in regulating LT-HSCs. PRINCIPLE FINDINGS:Here we demonstrate that PDK1 activity is crucial for transplantable HSC function. Whereas Pdkl, Pdk2, and Pdk3 transcripts were expressed at higher levels in different subtypes of HSCs compared to differentiated cells, we could not detect any major differences in expression between LT-HSCs and more short-term HSCs and multipotent progenitors. When studying HIF-1α-mediated regulation of Pdk activity in vitro, Pdk1 was the most robust target regulated by hypoxia, whereas Pdk2, Pdk3, and Pdk4 were not affected. Contrary, genetic ablation in a cre-inducible Hif-1α knockout mouse did not support a link between HIF-1α and Pdk1. Silencing of Pdk1 by shRNA lentiviral gene transfer partially impaired progenitor colony formation in vitro and had a strong negative effect on both long-term and short-term engraftment in mice. CONCLUSIONS:Our study demonstrates that PDK1 has broad effects in hematopoiesis and is a critical factor for engraftment of both HSCs and multipotent progenitors upon transplantation to recipient mice. While Pdk1 was a robust hypoxia-inducible gene mediated by HIF-1α in vitro, we could not find evidence of any in vivo links between Pdk1 and HIF-1α

Hypoxia Expands Primitive Hematopoietic Progenitor Cells from Mouse Bone Marrow During In Vitro Culture and Preserves the Colony-Forming Ability

Self-renewal is a prerequisite for the maintenance of hematopoietic stem cells (HSCs) in the bone marrow throughout adult life. Cytokines are mainly providing pro-survival signals of HSC, whereas low oxygen levels (hypoxia) were recently shown to influence self-renewal. In contrast, the effects on other progenitor cell types is not clear. In the present work, we have analyzed whether hypoxia has any effects on mouse multipotent progenitors. When bone marrow-derived Lin-Sca1+c-kit+ (LSK) cells were kept in hypoxic cultures (1% O2 ) for 4 days together with cytokines, the numbers of colony forming high-proliferative progenitors (HPP-CFC) and precursors for cobble-stone forming cells (CAFC) were increased compared to normoxic conditions. A similar effect was seen with pre-CFCmulti from unfractionated bone marrow, whereas more committed progenitors (CFU-GM) were expanded better in normoxia compared to hypoxia. The observed increase in numbers of primitive colony-forming progenitor cells was associated with maintenance of the c-kit/Sca-1 phenotype and a preferential expansion of immature  blast-like appearing cells. The results suggest that a major function of hypoxia is to regulate differentiation by increased self-renewal. Furthermore, in cultures of limited cytokine supply, survival of the stem cell-like cell line FDCP-mix was increased during hypoxia. Thus, hypoxia allows for better survival and self-renewal of multipotent progenitors and HSCs from adult bone marrow. Such culture conditions may have beneficial clinical implications for ex vivo purposes and may improve the yields of stem cells and early progenitors.Original Publication: Pernilla Eliasson, Richard Karlsson and Jan-Ingvar Jönsson, Hypoxia Expands Primitive Hematopoietic Progenitor Cellsfrom Mouse Bone Marrow During In Vitro Culture and Preserves the Colony-Forming Ability, 2006, Journal of Stem Cells, (1), 4, 247-257. https://www.novapublishers.com/catalog/editorial.php?products_id=3730 Copyright: Nova Science Publishers https://www.novapublishers.com/</p

Hypoxia Expands Primitive Hematopoietic Progenitor Cells from Mouse Bone Marrow During In Vitro Culture and Preserves the Colony-Forming Ability

Self-renewal is a prerequisite for the maintenance of hematopoietic stem cells (HSCs) in the bone marrow throughout adult life. Cytokines are mainly providing pro-survival signals of HSC, whereas low oxygen levels (hypoxia) were recently shown to influence self-renewal. In contrast, the effects on other progenitor cell types is not clear. In the present work, we have analyzed whether hypoxia has any effects on mouse multipotent progenitors. When bone marrow-derived Lin-Sca1+c-kit+ (LSK) cells were kept in hypoxic cultures (1% O2 ) for 4 days together with cytokines, the numbers of colony forming high-proliferative progenitors (HPP-CFC) and precursors for cobble-stone forming cells (CAFC) were increased compared to normoxic conditions. A similar effect was seen with pre-CFCmulti from unfractionated bone marrow, whereas more committed progenitors (CFU-GM) were expanded better in normoxia compared to hypoxia. The observed increase in numbers of primitive colony-forming progenitor cells was associated with maintenance of the c-kit/Sca-1 phenotype and a preferential expansion of immature  blast-like appearing cells. The results suggest that a major function of hypoxia is to regulate differentiation by increased self-renewal. Furthermore, in cultures of limited cytokine supply, survival of the stem cell-like cell line FDCP-mix was increased during hypoxia. Thus, hypoxia allows for better survival and self-renewal of multipotent progenitors and HSCs from adult bone marrow. Such culture conditions may have beneficial clinical implications for ex vivo purposes and may improve the yields of stem cells and early progenitors.Original Publication: Pernilla Eliasson, Richard Karlsson and Jan-Ingvar Jönsson, Hypoxia Expands Primitive Hematopoietic Progenitor Cellsfrom Mouse Bone Marrow During In Vitro Culture and Preserves the Colony-Forming Ability, 2006, Journal of Stem Cells, (1), 4, 247-257. https://www.novapublishers.com/catalog/editorial.php?products_id=3730 Copyright: Nova Science Publishers https://www.novapublishers.com/</p

Hypoxia Expands Primitive Hematopoietic Progenitor Cells from Mouse Bone Marrow During In Vitro Culture and Preserves the Colony-Forming Ability

Self-renewal is a prerequisite for the maintenance of hematopoietic stem cells (HSCs) in the bone marrow throughout adult life. Cytokines are mainly providing pro-survival signals of HSC, whereas low oxygen levels (hypoxia) were recently shown to influence self-renewal. In contrast, the effects on other progenitor cell types is not clear. In the present work, we have analyzed whether hypoxia has any effects on mouse multipotent progenitors. When bone marrow-derived Lin- Sca1 + c-kit + (LSK) cells were kept in hypoxic cultures (1 % O 2) for 4 days together with cytokines, the numbers of colony forming high-proliferative progenitors (HPP-CFC) and precursors for cobble-stone forming cells (CAFC) were increased compared to normoxic conditions. A simila