| 1. |
- Andersson, Hedvig, et al.
(författare)
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Emotional Dysregulation and Trauma Symptoms Mediate the Relationship Between Childhood Abuse and Nonsuicidal Self-Injury in Adolescents
- 2022
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Ingår i: Frontiers in Psychiatry. - : Frontiers Media SA. - 1664-0640. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundNonsuicidal self-injury (NSSI) is common in adolescents. Emotion dysregulation has been identified as a core mechanism in the development and maintenance of NSSI and it is therefore an important target when addressing NSSI. The pathogenic connection between different kinds of childhood abuse, difficulties in emotion regulation and NSSI needs further investigation. The objective of this study was to examine whether difficulties with emotion regulation and trauma symptoms, separately and together, mediate the relationships between sexual, physical and emotional abuse and NSSI. MethodCross-sectional data was collected from 3,169 adolescent high-school students aged 16-19 years (M = 18.12, SD = 0.45). Data from self-reported experiences of childhood abuse, current difficulties with emotion regulation (measured with the Difficulties with Emotion Regulation Scale, DERS-16) and trauma symptoms (measured with the Trauma Symptom Checklist for Children, TSCC), and NSSI were collected. Structural Equation Modeling (SEM) was used to test the proposed relationships between variables. ResultsThe prevalence of life-time NSSI was 27.4%. Prevalence of reported childhood abuse was 9.2, 17.5, and 18.0% for sexual, physical, and emotional abuse, respectively. Childhood abuse, difficulties with emotion regulation and trauma symptoms exhibited significant positive associations with NSSI in adolescents. Emotional dysregulation and trauma symptoms were both found to mediate the relationship between childhood abuse and NSSI. Latent variable models were found to fit data well. ConclusionResults indicate that increased levels of emotional dysregulation and trauma symptoms in relation to childhood abuse contribute to the increased risk of NSSI. Further, results point to some aspects of emotional dysregulation and trauma symptoms being more important in this regard. Clinical implications are discussed.
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| 2. |
- Aspeqvist, Erik, 1983-, et al.
(författare)
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Measurement and stratification of nonsuicidal self-injury in adolescents
- 2024
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Ingår i: BMC Psychiatry. - : BMC. - 1471-244X. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundNonsuicidal self-injury (NSSI) is highly prevalent in adolescents. In survey and interview studies assessing NSSI, methods of assessment have been shown to influence prevalence estimates. However, knowledge of which groups of adolescents that are identified with different measurement methods is lacking, and the characteristics of identified groups are yet to be investigated. Further, only a handful of studies have been carried out using exploratory methods to identify subgroups among adolescents with NSSI.MethodsThe performance of two prevalence measures (single-item vs. behavioral checklist) in the same cross-sectional community sample (n = 266, age M = 14.21, 58.3% female) of adolescents was compared regarding prevalence estimates and also characterization of the identified groups with lifetime NSSI prevalence. A cluster analysis was carried out in the same sample. Identified clusters were compared to the two groups defined using the prevalence measures.ResultsA total of 118 (44.4%) participants acknowledged having engaged in NSSI at least once. Of these, a group of 55 (20.7%) adolescents confirmed NSSI on a single item and 63 (23.7%) adolescents confirmed NSSI only on a behavioral checklist, while denying NSSI on the single item. Groups differed significantly, with the single-item group being more severely affected and having higher mean scores on difficulties in emotion regulation, self-criticism, number of methods, higher frequency of NSSI, higher rates of suicidal ideation and suicidal behavior and lower mean score on health-related quality of life. All cases with higher severity were not identified by the single-item question. Cluster analysis identified three clusters, two of which fit well with the groups identified by single-item and behavioral checklist measures.ConclusionsWhen investigating NSSI prevalence in adolescents, findings are influenced by the researchers' choice of measures. The present study provides some directions toward what kind of influence to expect given the type of measure used, both with regards to the size of the identified group and its composition. Implications for future research as well as clinical and preventive work are discussed.
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| 3. |
- Beckman-Sundh, Ulla, et al.
(författare)
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A screening method for phosphohistidine phosphatase 1 activity
- 2011
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Ingår i: Upsala Journal of Medical Sciences. - : Uppsala Medical Society. - 0300-9734 .- 2000-1967. ; 116:3, s. 161-168
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Tidskriftsartikel (refereegranskat)abstract
- Introduction. Research in the field of protein-bound phosphohistidine phosphorylation has been hampered by the difficulties in analysis and detection of phosphohistidine. Therefore a screening method was developed primarily for the analysis of phosphohistidine phosphatase 1 (PHPT1) activity. Methods. A highly positively charged substrate, Ac-Val-Arg-Leu-Lys-His-Arg-Lys-Leu-Arg-pNA, containing the peptide surrounding the phosphorylated histidine in ion channel KCa3.1 was chemically phosphorylated using phosphoramidate. Excess phosphoramidate was removed by anion exchange chromatography using a micro spin column. After incubation of the eluate with PHPT1, the removed phosphate was bound on a consecutive anion exchange spin column. The eluate was assayed in a micro plate format for remaining phosphate in the substrate Ac-Val-Arg-Leu-Lys-His(P)-Arg-Lys-Leu-Arg-pNA. Histone H4, also highly positive in charge, was subjected to the same procedure to explore the possibility to use other substrates to PHPT1 in this assay format. Results. It was found that Ac-Val-Arg-Leu-Lys-His(P)-Arg-Lys-Leu-Arg-pNA and phosphohistone H4 were dephosphorylated by PHPT1. The apparent K(m) for Ac-Val-Arg-Leu-Lys-His(P)-Arg-Lys-Leu-Arg-pNA was in the order of 10 mu M. Using this method, phosphohistidine phosphatase activity was detected in mouse liver cell sap with Ac-Val-Arg-Leu-Lys-His(P)-Arg-Lys-Leu-Arg-pNA as substrate. Discussion. The described method for determination of PHPT1 activity is comparably much easier and faster than presently used methods for detection of phosphohistidine phosphatase activity. It is also sensitive, since the lower activity limit was 5 pmol phosphate released per min. It has the potential to be used both for more rapid screening for inhibitors and activators to phosphohistidine phosphatases and for screening of histidine kinases.
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| 4. |
- Beckman Sundh, Ulla, 1953-
(författare)
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Studies on Phosphohistidine Phosphatase 1 : What? Where? Why?
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Phosphohistidine phosphatase 1 (PHPT1) is a small protein, consisting of 125 amino acids, that catalyzes the dephosphorylation of histidine but does not have any activity towards other phosphorylated amino acids. PHPT1 was identified in 2002, and is so far the only mammalian histidine phosphatase known, but still little is known about its physiological role. No mammalian histidine kinases have hitherto been identified.Phosphorylation is one of the most important ways in which the structure and activity of a protein may be changed after translation. Proteins are phosphorylated on the side chain of amino acid residues. When a hydroxyl is phosphorylated the result is a phosphoester and when a nitrogen is phosphorylated the result is a phosphoamidate. Histidine may be phosphorylated on either of the two nitrogens of the imidazole ring of the side chain. The resulting phosphoamidate bond is labile and rich in energy, which makes histidine phosphorylation highly reversible and flexible. However, histidine phosphorylation is less studied than that of the phosphoesters due to the acid lability of the phosphoamidate bond.The work described in this thesis was focused on further elucidating the physiological role of PHPT1. Amino acid residues of importance for the activity of PHPT1 were identified, and mutants with decreased phosphatase activity were produced. These mutants have been used in studies on the function of PHPT1. By using immunohistochemical methodology the localization of PHPT1 in both mouse and human tissues was determined, with mainly similar results. A general finding was that expression of PHPT1 was high in epithelial cells with short turnover time, indicating that PHPT1 may have an important role in proliferating cells. We have also developed a comparatively fast and simple screening method for determination of PHPT1 activity. Since research in this field has been hampered by the lack of efficient and practical methodology, hopefully this new method will be an asset in search of inhibitors for PHPT1, which in turn may be used for detection of the elusive mammalian histidine kinases, the finding of which may give major breakthroughs in the field.
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| 5. |
- Dahlström, Örjan, et al.
(författare)
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Functions of Nonsuicidal Self-Injury: Exploratory and Confirmatory Factor Analyses in a Large Community Sample of Adolescents
- 2015
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Ingår i: Psychological Assessment. - : American Psychological Association (APA). - 1040-3590 .- 1939-134X. ; 27:1, s. 302-313
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Tidskriftsartikel (refereegranskat)abstract
- Given that nonsuicidal self-injury (NSSI) is prevalent in adolescents, structured assessment is an essential tool to guide treatment interventions. The Functional Assessment of Self-Mutilation (FASM) is a self-report scale that assesses frequency, methods, and functions of NSSI. FASM was administered to 3,097 Swedish adolescents in a community sample. With the aim of examining the underlying factor structure of the functions of FASM in this sample, the adolescents with NSSI who completed all function items (n = 836) were randomly divided into 2 subsamples for cross-validation purposes. An exploratory factor analysis (EFA) was followed by a confirmatory factor analysis (CFA) using the mean and variance adjusted weighted least squares (WLSMV) estimator in the Mplus statistical modeling program. The results of the EFA suggested a 3-factor model (social influence, automatic functions, and nonconformist peer identification), which was supported by a good fit in the CFA. Factors differentiated between social/interpersonal and automatic/intrapersonal functions. Based on learning theory and the specific concepts of negative and positive reinforcement, the nonconformist peer identification factor was then split into 2 factors (peer identification and avoiding demands). The resulting 4-factor model showed an excellent fit. Dividing social functions into separate factors (social influence, peer identification, and avoiding demands) can be helpful in clinical practice, where the assessment of NSSI functions is an important tool with direct implications for treatment.
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| 6. |
- Edlund, Bror, et al.
(författare)
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Amino acid sequence at the phosphorylated site of rat liver pyruvate kinase
- 1975
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - 0006-291X .- 1090-2104. ; 67:4, s. 1516-1521
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Tidskriftsartikel (refereegranskat)abstract
- One dominating peptic phosphopeptide, Asx-Thr-Lys-Gly-Pro-Glx-Ile-Glx-Thr-Gly-Val-Leu-Arg-Arg-Ala-(32P)SerP-Val-Ala-Glx-Leu, was obtained from rat liver pyruvate kinase (type L) phosphorylated by cyclic 3′,5′-AMP-stimulated protein kinase from the same tissue. The sequence around the phosphorylated serine residue is similar to that of a corresponding but smaller peptic phosphopeptide previously isolated from pig liver (type L) pyruvate kinase, Leu-Arg-Arg-Ala-(32P)SerP-Leu.
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| 7. |
- Ek, Pia, et al.
(författare)
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Identification and characterization of a mammalian 14-kDa phosphohistidine phosphatase
- 2002
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Ingår i: European Journal of Biochemistry. - : Wiley. - 0014-2956 .- 1432-1033. ; 269, s. 5016-5023
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Tidskriftsartikel (refereegranskat)abstract
- Protein histidine phosphorylation in eukaryotes has beensparsely studied compared to protein serine/threonine andtyrosine phosphorylation. In an attempt to rectify this byprobing porcine liver cytosol with the phosphohistidinecontainingpeptide succinyl-Ala-His(P)-Pro-Phe-p-nitroanilide(phosphopeptide I), we observed a phosphataseactivity that was insensitive towards okadaic acid andEDTA. This suggested the existence of a phosphohistidinephosphatase different from protein phosphatase 1, 2Aand 2C. A 1000-fold purification to apparent homogeneitygave a 14-kDa phosphatase with a specific activity of 3lmolÆmin)1Æmg)1 at pH 7.5 with 7 lM phosphopeptide Ias substrate. Partial amino-acid sequence determination ofthe purified porcine enzyme by MS revealed similaritywith a human sequence representing a human chromosome9 gene of hitherto unknown function. Molecularcloning from a human embryonic kidney cell cDNAlibraryfollowed by expression and purification, yielded aprotein with a molecular mass of 13 700 Da, and anEDTA-insensitive phosphohistidine phosphatase activityof 9 lmolÆmin)1Æmg)1 towards phosphopeptide I. Nodetectable activity was obtained towards a set of phosphoserine-,phosphothreonine-, and phosphotyrosine peptides.Northern blot analysis indicated that the humanphosphohistidine phosphatase mRNA was present preferentiallyin heart and skeletal muscle. These resultsprovide a new tool for studying eukaryotic histidinephosphorylation/dephosphorylation.
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| 8. |
- Ek, Pia, et al.
(författare)
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Phosphohistidine phosphatase 1 (PHPT1) also dephosphorylates phospholysine of chemically phosphorylated histone H1 and polylysine
- 2015
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Ingår i: Upsala Journal of Medical Sciences. - : Uppsala Medical Society. - 0300-9734 .- 2000-1967. ; 120:1, s. 20-27
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Tidskriftsartikel (refereegranskat)abstract
- Background. Phosphohistidine phosphatase 1 (PHPT1), also named protein histidine phosphatase (PHP), is a eukaryotic enzyme dephosphorylating proteins and peptides that are phosphorylated on a histidine residue. A preliminary finding that histone H1, which lacks histidine, was phosphorylated by phosphoramidate and dephosphorylated by PHPT1 prompted the present investigation. Methods. Histone H1 and polylysine were phosphorylated at a low concentration (3.9 mM) of phosphoramidate. Their dephosphorylation by recombinant human PHPT1 was investigated by using a DEAE-Sepharose spin column technique earlier developed by us for studies on basic phosphoproteins and phosphopeptides. Determination of protein-bound, acid-labile phosphate was performed by a malachite green method. Mass spectrometry (MS) was used to investigate the occurrence of N-epsilon-phospholysine residues in a phosphorylated histone H 1.2 preparation, and to measure the activity of PHPT1 against free N-omega-phosphoarginine. Results. Histone H1.2, which lacks histidine, was phosphorylated by phosphoramidate on several lysine residues, as shown by MS. PHPT1 was shown to dephosphorylate phosphohistone H1 at a rate similar to that previously described for the dephosphorylation of phosphohistidine-containing peptides. In addition, phosphopolylysine was an equally good substrate for PHPT1. However, no dephosphorylation of free phosphoarginine by PHPT1 could be detected. Conclusion. The finding that PHPT1 can dephosphorylate phospholysine in chemically phosphorylated histone H1 and polylysine demonstrates a broader specificity for this enzyme than known so far.
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| 9. |
- Engström, Lorentz, et al.
(författare)
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Pyruvate kinase
- 1987
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Ingår i: The enzymes. - : Elsevier. - 9780121227180 ; , s. 47-75
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Bokkapitel (refereegranskat)
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| 10. |
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