222 research outputs found
Mortality in Norway and Sweden during the COVID-19 pandemic
Background: Norway and Sweden are similar countries in terms of socioeconomics and health care. Norway implemented extensive COVID-19 measures, such as school closures and lockdowns, whereas Sweden did not. Aims: To compare mortality in Norway and Sweden, two similar countries with very different mitigation measures against COVID-19.
Methods: Using real-world data from national registries, we compared all-cause and COVID-19-related mortality rates with 95% confidence intervals (CI) per 100,000 person-weeks and mortality rate ratios (MRR) comparing the five preceding years (2015–2019) with the pandemic year (2020) in Norway and Sweden.
Results: In Norway, all-cause mortality was stable from 2015 to 2019 (mortality rate 14.6–15.1 per 100,000 person-weeks; mean mortality rate 14.9) and was lower in 2020 than from 2015 to 2019 (mortality rate 14.4; MRR 0.97; 95% CI 0.96–0.98). In Sweden, all-cause mortality was stable from 2015 to 2018 (mortality rate 17.0–17.8; mean mortality rate 17.1) and similar to that in 2020 (mortality rate 17.6), but lower in 2019 (mortality rate 16.2). Compared with the years 2015–2019, all-cause mortality in the pandemic year was 3% higher due to the lower rate in 2019 (MRR 1.03; 95% CI 1.02–1.04). Excess mortality was confined to people aged ⩾70 years in Sweden compared with previous years. The COVID-19-associated mortality rates per 100,000 person-weeks during the first wave of the pandemic were 0.3 in Norway and 2.9 in Sweden.
Conclusions: All-cause mortality in 2020 decreased in Norway and increased in Sweden compared with previous years. The observed excess deaths in Sweden during the pandemic may, in part, be explained by mortality displacement due to the low all-cause mortality in the previous year
Urinary tract infections in children after renal transplantation
Urinary tract infections (UTI) after pediatric kidney transplantation (KTX) are an important clinical problem and occur in 15–33% of patients. Febrile UTI, whether occurring in the transplanted kidney or the native kidney, should be differentiated from afebrile UTI. The latter may cause significant morbidity and is usually associated with acute graft dysfunction. Risk factors for (febrile) UTI include anatomical, functional, and demographic factors as well as baseline immunosuppression and foreign material, such as catheters and stents. Meticulous surveillance, diagnosis, and treatment of UTI is important to minimize acute morbidity and compromise of long-term graft function. In febrile UTI, parenteral antibiotics are usually indicated, although controlled data are not available. As most data concerning UTI have been accumulated retrospectively, future prospective studies have to be performed to clarify pathogenetic mechanisms and risk factors, improve prophylaxis and treatment, and ultimately optimize long-term renal graft survival
Intestinal Epithelial Stem/Progenitor Cells Are Controlled by Mucosal Afferent Nerves
Background: The maintenance of the intestinal epithelium is of great importance for the survival of the organism. A possible nervous control of epithelial cell renewal was studied in rats and mice. Methods: Mucosal afferent nerves were stimulated by exposing the intestinal mucosa to capsaicin (1.6 mM), which stimulates intestinal external axons. Epithelial cell renewal was investigated in the jejunum by measuring intestinal thymidine kinase (TK) activity, intestinal H-3-thymidine incorporation into DNA, and the number of crypt cells labeled with BrdU. The influence of the external gut innervation was minimized by severing the periarterial nerves. Principal Findings: Luminal capsaicin increased all the studied variables, an effect nervously mediated to judge from inhibitory effects on TK activity or H-3-thymidine incorporation into DNA by exposing the mucosa to lidocaine (a local anesthetic) or by giving four different neurotransmitter receptor antagonists i.v. (muscarinic, nicotinic, neurokinin1 (NK1) or calcitonin gene related peptide (CGRP) receptors). After degeneration of the intestinal external nerves capsaicin did not increase TK activity, suggesting the involvement of an axon reflex. Intra-arterial infusion of Substance P (SP) or CGRP increased intestinal TK activity, a response abolished by muscarinic receptor blockade. Immunohistochemistry suggested presence of M3 and M5 muscarinic receptors on the intestinal stem/progenitor cells. We propose that the stem/progenitor cells are controlled by cholinergic nerves, which, in turn, are influenced by mucosal afferent neuron(s) releasing acetylcholine and/or SP and/or CGRP. In mice lacking the capsaicin receptor, thymidine incorporation into DNA and number of crypt cells labeled with BrdU was lower than in wild type animals suggesting that nerves are important also in the absence of luminal capsaicin, a conclusion also supported by the observation that atropine lowered thymidine incorporation into DNA by 60% in control rat segments. Conclusion: Enteric nerves are of importance in maintaining the intestinal epithelial barrier.Original Publication:Ove Lundgren, Mats Jodal, Madeleine Jansson, Anders T Ryberg and Lennart Svensson, Intestinal Epithelial Stem/Progenitor Cells Are Controlled by Mucosal Afferent Nerves, 2011, PLOS ONE, (6), 2, 16295.http://dx.doi.org/10.1371/journal.pone.0016295Copyright: Public Library of Science (PLoS)http://www.plos.org
A Genetic Basis of Susceptibility to Acute Pyelonephritis
For unknown reasons, urinary tract infections (UTIs) are clustered in certain individuals. Here we propose a novel, genetically determined cause of susceptibility to acute pyelonephritis, which is the most severe form of UTI. The IL-8 receptor, CXCR1, was identified as a candidate gene when mIL-8Rh mutant mice developed acute pyelonephritis (APN) with severe tissue damage.We have obtained CXCR1 sequences from two, highly selected APN prone patient groups, and detected three unique mutations and two known polymorphisms with a genotype frequency of 23% and 25% compared to 7% in controls (p<0.001 and p<0.0001, respectively). When reflux was excluded, 54% of the patients had CXCR1 sequence variants. The UTI prone children expressed less CXCR1 protein than the pediatric controls (p<0.0001) and two sequence variants were shown to impair transcription.The results identify a genetic innate immune deficiency, with a strong link to APN and renal scarring
Pathogen Specific, IRF3-Dependent Signaling and Innate Resistance to Human Kidney Infection
The mucosal immune system identifies and fights invading pathogens, while allowing non-pathogenic organisms to persist. Mechanisms of pathogen/non-pathogen discrimination are poorly understood, as is the contribution of human genetic variation in disease susceptibility. We describe here a new, IRF3-dependent signaling pathway that is critical for distinguishing pathogens from normal flora at the mucosal barrier. Following uropathogenic E. coli infection, Irf3−/− mice showed a pathogen-specific increase in acute mortality, bacterial burden, abscess formation and renal damage compared to wild type mice. TLR4 signaling was initiated after ceramide release from glycosphingolipid receptors, through TRAM, CREB, Fos and Jun phosphorylation and p38 MAPK-dependent mechanisms, resulting in nuclear translocation of IRF3 and activation of IRF3/IFNβ-dependent antibacterial effector mechanisms. This TLR4/IRF3 pathway of pathogen discrimination was activated by ceramide and by P-fimbriated E. coli, which use ceramide-anchored glycosphingolipid receptors. Relevance of this pathway for human disease was supported by polymorphic IRF3 promoter sequences, differing between children with severe, symptomatic kidney infection and children who were asymptomatic bacterial carriers. IRF3 promoter activity was reduced by the disease-associated genotype, consistent with the pathology in Irf3−/− mice. Host susceptibility to common infections like UTI may thus be strongly influenced by single gene modifications affecting the innate immune response
A comparison of three (67/68)Ga-labelled exendin-4 derivatives for β-cell imaging on the GLP-1 receptor: the influence of the conjugation site of NODAGA as chelator.
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137674.pdf (publisher's version ) (Open Access)Various diseases derive from pathologically altered β-cells. Their function can be increased, leading to hyperinsulinism, or decreased, resulting in diabetes. Non-invasive imaging of the β-cell-specific glucagon-like peptide receptor-1 (GLP-1R) would allow the assessment of both β-cell mass and derived tumours, potentially improving the diagnosis of various conditions. We tested three new (67/68)Ga-labelled derivatives of exendin-4, an agonist of GLP-1R, in vitro and in vivo. We determined the influence of the chelator NODAGA conjugated to resident lysines either at positions 12 and 27 or the C-terminally attached lysine at position 40 on the binding and kinetics of the peptide.Binding and internalisation of (67)Ga-labelled Ex4NOD12, Ex4NOD27 and Ex4NOD40 were tested on Chinese hamster lung (CHL) cells stably transfected to express the GLP-1 receptor (GLP-1R). In vivo biodistribution of (68)Ga-labelled peptides was investigated in CD1 nu/nu mice with subcutaneous CHL-GLP-1R positive tumours; the specificity of the binding to GLP-1R was determined by pre-injecting excess peptide.All peptides showed good in vitro binding affinities to GLP-1R in the range of 29 to 54 nM. (67/68)Ga-Ex4NOD40 and (67/68)Ga-Ex4NOD12 show excellent internalisation (>30\%) and high specific uptake in GLP-1R positive tissue, but high activity was also found in the kidneys.We show that of the three peptides, Ga-Ex4NOD40 and Ga-Ex4NOD12 demonstrate the most favourable in vitro properties and in vivo binding to GLP-1R positive tissue. Therefore, we conclude that the lysines at positions 12 and 40 might preferentially be utilised for modifying exendin-4
Involvement of nerves and calcium channels in the intestinal response to Clostridium difficile toxin A: an experimental study in rats in vivo
BACKGROUND—The involvement of nerves and calcium channels in the intestinal response to Clostridium difficile toxin A (luminal concentration 1 or 15 µg/ml) was studied in the small intestine of rats in vivo.
METHODS—Inflammation was quantified by estimating myeloperoxidase (MPO) activity in the intestinal lumen, extravascular accumulation of Evan's blue (EB) in the intestine, and number of red blood cells (RBCs) in veins in histological sections. Intestinal damage was estimated using a histological grading system. In some experiments net fluid transport was recorded using a gravimetric technique.
RESULTS—In acutely denervated intestines, toxin A caused marked destruction of the villi, increased luminal release of MPO activity, and augmentation of intestinal content of EB and venous RBCs. Denervating the intestine 3-4 weeks prior to the actual experiment prevented the development of villus damage and significantly decreased the number of RBCs in intestinal veins in experiments with a low toxin concentration, whereas no effect was demonstrated on luminal MPO activity. Using a high toxin concentration, chronic denervation decreased only the number of RBCs. Pretreatment with hexamethonium (low toxin concentration; acute denervation) attenuated the effect of toxin A on morphology, luminal MPO activity, and number of RBCs. Pretreatment with nifedipine (low toxin concentration; acute denervation) significantly decreased intestinal MPO activity and number of RBCs. Tissue accumulation of EB was not influenced by experimental manipulation. Net fluid transport was measured in experiments exposing the intestinal mucosa to a high toxin concentration. Fluid secretion caused by the toxin was significantly attenuated by intravenous hexamethonium whereas no effect was observed after administration of nifedipine or granisetron.
CONCLUSIONS—At a low toxin concentration, intramural reflexes are involved in the inflammatory response whereas axon reflexes contribute to tissue damage. At a high toxin concentration no nervous involvement in the toxin A response was demonstrated except for fluid secretion evoked by the toxin.
Keywords: cholera toxin; enteric nervous system; 5-hydroxytryptamine; myeloperoxidase; red blood cell
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