1
|
Hokynar K, Rantakokko-Jalava K, Hakanen A, Havana M, Mannonen L, Jokela P, Kurkela S, Lappalainen M, Unemo M, Puolakkainen M. The Finnish New Variant of Chlamydia trachomatis with a Single Nucleotide Polymorphism in the 23S rRNA Target Escapes Detection by the Aptima Combo 2 Test. Microorganisms 2019; 7:microorganisms7080227. [PMID: 31370214 PMCID: PMC6723375 DOI: 10.3390/microorganisms7080227] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 07/28/2019] [Accepted: 07/29/2019] [Indexed: 01/18/2023] Open
Abstract
In 2019, more than 200 cases of Chlamydia trachomatis negative/equivocal by the Aptima Combo 2 assay (AC2, target: 23S rRNA) with slightly elevated relative light units (RLUs), but positive by the Aptima Chlamydia trachomatis assay (ACT, target: 16S rRNA) have been detected in Finland To identify the cause of the AC2 CT false-negative specimens, we sequenced parts of the CT 23S rRNA gene in 40 specimens that were AC2 negative/equivocal but ACT positive. A single nucleotide polymorphism (SNP; C1515T in the C. trachomatis 23S rRNA gene) was revealed in 39 AC2/ACT discordant specimens. No decrease in the number of mandatorily notified C. trachomatis cases was observed nationally in Finland in 2010–2019. When RLUs obtained for AC2 negative specimens were retrospectively evaluated in 2011–2019, a continuous increase in the proportion of samples with RLUs 10–19 was observed since 2014, and a slight increase in the proportion of samples with RLUs 20–84 in 2017–2019, indicating that the Finnish new variant of C. trachomatis might have been spreading nationally for several years. This emphasizes that careful surveillance of epidemiology, positivity rate and test performance are mandatory to detect any changes affecting detection of infections.
Collapse
Affiliation(s)
- Kati Hokynar
- Virology, University of Helsinki and Helsinki University Hospital, Helsinki 00014, Finland
| | - Kaisu Rantakokko-Jalava
- Department of Clinical Microbiology, Turku University Hospital, Turku 20500, Finland
- Department of Virology, University of Turku, Turku 20500, Finland
| | - Antti Hakanen
- Department of Clinical Microbiology, Turku University Hospital, Turku 20500, Finland
- Department of Virology, University of Turku, Turku 20500, Finland
| | | | - Laura Mannonen
- Virology, University of Helsinki and Helsinki University Hospital, Helsinki 00014, Finland
| | - Pia Jokela
- Virology, University of Helsinki and Helsinki University Hospital, Helsinki 00014, Finland
| | - Satu Kurkela
- Virology, University of Helsinki and Helsinki University Hospital, Helsinki 00014, Finland
| | - Maija Lappalainen
- Virology, University of Helsinki and Helsinki University Hospital, Helsinki 00014, Finland
| | - Magnus Unemo
- World Health Organization (WHO) Collaborating Centre for Gonorrhoea and other Sexually Transmitted Infections (STIs), National Reference Laboratory for STIs, Department of Laboratory Medicine, Faculty of Medicine and Health, Örebro University, SE-701 85 Örebro, Sweden
| | - Mirja Puolakkainen
- Virology, University of Helsinki and Helsinki University Hospital, Helsinki 00014, Finland.
| |
Collapse
|
2
|
Petäjä EM, Zhou Y, Havana M, Hakkarainen A, Lundbom N, Ihalainen J, Yki-Järvinen H. Phosphorylated IGFBP-1 as a non-invasive predictor of liver fat in NAFLD. Sci Rep 2016; 6:24740. [PMID: 27091074 PMCID: PMC4835723 DOI: 10.1038/srep24740] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 04/04/2016] [Indexed: 12/23/2022] Open
Abstract
Insulin-like growth factor binding protein 1 (IGFBP-1) is a potentially interesting marker for liver fat in NAFLD as it is exclusively produced by the liver, and insulin is its main regulator. We determined whether measurement of fasting serum phosphorylated IGFBP-1 (fS-pIGFBP-1) helps to predict liver fat compared to routinely available clinical parameters and PNPLA3 genotype at rs738409. Liver fat content (proton magnetic resonance spectroscopy) was measured in 378 subjects (62% women, age 43 [30-54] years, BMI 32.7 [28.1-39.7] kg/m(2), 46% with NAFLD). Subjects were randomized to discovery and validation groups, which were matched for clinical and biochemical parameters and PNPLA3 genotype. Multiple linear regression and Random Forest modeling were used to identify predictors of liver fat. The final model, % Liver Fat Equation', included age, fS-pIGFBP-1, S-ALT, waist-to-hip ratio, fP-Glucose and fS-Insulin (adjusted R(2) = 0.44 in the discovery group, 0.49 in the validation group, 0.47 in all subjects). The model was significantly better than a model without fS-pIGFBP-1 or S-ALT or S-AST alone. Random Forest modeling identified fS-p-IGFBP-1 as one of the top five predictors of liver fat (adjusted R(2) = 0.39). Therefore, measurement of fS-pIGFBP-1 may help in non-invasive prediction of liver fat content.
Collapse
Affiliation(s)
- Elina M Petäjä
- Minerva Foundation Institute for Medical Research, Helsinki, Finland.,Department of Medicine, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - You Zhou
- Minerva Foundation Institute for Medical Research, Helsinki, Finland.,Systems Immunity University Research Institute and Division of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | | | - Antti Hakkarainen
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | - Nina Lundbom
- HUS Medical Imaging Center, Radiology, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | | | - Hannele Yki-Järvinen
- Minerva Foundation Institute for Medical Research, Helsinki, Finland.,Department of Medicine, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| |
Collapse
|
3
|
Hyvönen ME, Saurus P, Wasik A, Heikkilä E, Havana M, Trokovic R, Saleem M, Holthöfer H, Lehtonen S. Lipid phosphatase SHIP2 downregulates insulin signalling in podocytes. Mol Cell Endocrinol 2010; 328:70-9. [PMID: 20654688 DOI: 10.1016/j.mce.2010.07.016] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 06/24/2010] [Accepted: 07/12/2010] [Indexed: 11/15/2022]
Abstract
Podocyte injury plays an important role in the development of diabetic nephropathy. Podocytes are insulin-responsive and can develop insulin resistance, but the mechanisms are unknown. To study the role of CD2-associated protein (CD2AP) in podocyte injury, we performed a yeast two-hybrid screening on a glomerular library, and found that CD2AP bound to SH2-domain-containing inositol polyphosphate 5-phosphatase 2 (SHIP2), a negative regulator of insulin signalling. SHIP2 interacts with CD2AP in glomeruli and is expressed in podocytes, where it translocates to plasma membrane after insulin stimulation. Overexpression of SHIP2 in cultured podocytes reduces Akt activation in response to insulin, and promotes apoptosis. SHIP2 is upregulated in glomeruli of insulin resistant obese Zucker rats. These results indicate that SHIP2 downregulates insulin signalling in podocytes. The upregulation of SHIP2 in Zucker rat glomeruli prior to the age of onset of proteinuria suggests a possible role for SHIP2 in the development of podocyte injury.
Collapse
Affiliation(s)
- Mervi E Hyvönen
- Department of Pathology, Haartman Institute, University of Helsinki, Helsinki, Finland
| | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Heikkilä E, Ristola M, Endlich K, Lehtonen S, Lassila M, Havana M, Endlich N, Holthöfer H. Densin and beta-catenin form a complex and co-localize in cultured podocyte cell junctions. Mol Cell Biochem 2007; 305:9-18. [PMID: 17581699 DOI: 10.1007/s11010-007-9522-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Accepted: 05/16/2007] [Indexed: 11/29/2022]
Abstract
Densin is a member of LAP (leucine-rich repeat and PDZ domain) protein family that localizes in kidney to slit diaphragms, which are essential components of the glomerular filtration barrier. We have previously shown that densin interacts with a crucial slit diaphragm protein, nephrin. Here, we searched for novel binding partners of densin by yeast-two hybrid assay and identified beta-catenin. The interaction was confirmed by reciprocal co-immunoprecipitation assay and the binding site in densin was determined by GST-pull down assays. The GST-tagged densin was also able to pull down P-cadherin together with beta-catenin from human kidney glomerular lysates. Furthermore, densin co-localized with beta-catenin and F-actin in cell-cell contacts in cultured mouse podocytes. During cell-cell contact disruption and reformation densin and beta-catenin were dislocated from and relocated back to plasma membrane in a similar fashion. These and our previous findings suggest that densin may associate with the cadherin-catenin and nephrin complex(es), and may be involved in the formation of the cell-cell contacts including the slit diaphragm.
Collapse
Affiliation(s)
- Eija Heikkilä
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Abstract
Diabetic nephropathy is the leading cause of end-stage renal disease. Because early diagnosis and treatment may prevent the complication, new tools for an early detection are needed. One of the key components of the glomerular filtration slit spanning between neighboring podocytes is nephrin. Its expression is altered in experimental models of diabetes and also in various human proteinuric diseases, including diabetes. We studied whether type 1 diabetic patients with or without nephropathy exhibit immunoreactive nephrin in the urine, reflecting early damage of the filtration barrier. Diabetic patients with normoalbuminuria (n = 40), with microalbuminuria (n = 41), and with macroalbuminuria (n = 39) and patients previously normoalbuminuric but now testing positive for microalbuminuria (newMicro, n = 39) were screened for nephrinuria with Western blotting using two affinity-purified anti-nephrin antibodies. Nondiabetic healthy subjects (n = 29) were also studied. Nephrinuria was present in 30% of normoalbuminuric, 17% of microalbuminuric, 28% of macroalbuminuric, and 28% of newMicro patients. Of female patients, 35% were nephrinuric compared with only 19% of male patients (P = 0.02). None of the control subjects was nephrinuric. In conclusion, glomerular filtration barrier may be affected in one-third of diabetic patients manifesting as early nephrinuria. Nephrinuria may have prognostic value and become a marker of susceptibility for kidney complications in diabetes.
Collapse
Affiliation(s)
- Anu Pätäri
- Department of Bacteriology and Immunology, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
| | | | | | | | | | | |
Collapse
|
6
|
Lappalainen J, Loikkanen S, Havana M, Karp M, Sjöberg AM, Wirtanen G. Microbial testing methods for detection of residual cleaning agents and disinfectants-prevention of ATP bioluminescence measurement errors in the food industry. J Food Prot 2000; 63:210-5. [PMID: 10678426 DOI: 10.4315/0362-028x-63.2.210] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The ATP luminescence measurement is based on the presence of an enzymatic reaction and may significantly be affected by cleaning agents and disinfectants. In addition, disinfectants can also reduce the activity of the luciferase enzyme and also act as ATP-releasing agents. The agents disrupt the cell walls but preserve ATP in measurable form, and therefore correlation with culture methods can be poor. Therefore, if a rapid method is used to detect ATP, a control must be used for reliable results. The possible effect of disinfectants can be eliminated with a rapid test to minimize sources of error. In the present study a microbiological residue testing method that is nonspecific for residues was developed. The effects of a total of 38 commercial cleaning agents and disinfectants of various types were assessed using two microbiological methods, the Vibrio fischeri photobacteria test and Micrococcus luteus inhibition zone technique. The results show that the V. fischeri photobacteria test is very sensitive. This test can therefore be used for testing cleaning agent residues on surfaces in very small amounts. A small study was also carried out in a food factory to show applicability in processing facilities. The study showed, that a need for this type of method exists in food processing.
Collapse
Affiliation(s)
- J Lappalainen
- University of Turku, Department of Biotechnology, Finland.
| | | | | | | | | | | |
Collapse
|