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Hasse Karlsson

Publications and source records attributed to Hasse Karlsson.

29 records · Page 2Linked to original sources
PubMed2004

A MUC1 tandem repeat reporter protein produced in CHO-K1 cells has sialylated core 1 O-glycans and becomes more densely glycosylated if coexpressed with polypeptide-GalNAc-T4 transferase.

A recombinant mucin O-glycosylation reporter protein, containing 1.7 tandem repeats (TRs) from the transmembrane mucin MUC1, was constructed. The reporter protein, MUC1(1.7TR)-IgG2a, was produced in CHO-K1 cells to study the glycosylation of the MUC1 TR and the in vivo role of polypeptide-GalNAc-T4 glycosyltransferase. N-terminal sequencing of MUC1(1.7TR)-IgG2a showed that all five potential O-glycosylation sites within the TR were used, with an average density of 4.5 glycans per repeat. The least occupied site was Thr in the PDTR motif, where 75% of the molecules were glycosylated, compared to 88-97% at the other sites. This glycan density was confirmed by an alternative liquid chromatography-mass spectrometry (LC-MS) based approach. The O-linked oligosaccharides were released from MUC1(1.7TR)-IgG2a and analyzed by nano-LC-MS and LC-MS/MS. Four oligosaccharides were present, NeuAcalpha2-3Galbeta1-3GalNAcol, NeuAcalpha2-3Galbeta1-3(NeuAcalpha2-6)GalNAcol, Galbeta1-3(NeuAcalpha2-6)GalNAcol, and Galbeta1-3GalNAcol, the two first being most abundant. Coexpression of the human polypeptide-GalNAc-T4 transferase with MUC1(1.7TR)-IgG2a increased the glycan occupancy at Thr in PDTR, Ser in VTSA, and Ser in GSTA, supporting the function of GalNAc-T4 proposed from previous in vitro studies. The expression of GalNAc-T4 with a mutation in the first lectin domain (alpha) had no glycosylation effect on PDTR and GSTA but surprisingly gave a dominant negative effect with a decreased glycosylation to around 50% at the Ser in VTSA. The results show that introduction of glycosyltransferases can specifically alter the sites for O-glycosylation in vivo.

Animals↗
PubMed2004

Volumes of the caudate nuclei in women with somatization disorder and healthy women.

Very little is known about the pathophysiology of somatization disorder. This study was designed to analyze the volumes of some brain structures possibly involved in somatization based on the observation of glucose metabolism of the brain in these patients. We studied 10 female patients with a diagnosis of somatization disorder or undifferentiated somatoform disorder with no comorbid current DSM-IV Axis I disorder and compared them to 16 healthy female volunteers using brain MRI (1.5 T instrument). The patients had bilateral enlargement of caudate nuclei volumes compared with healthy volunteers. These volume differences in the caudate nuclei could be associated with the pathophysiology of somatization.

Adult↗
PubMed2003

Recombinant MUC1 mucin with a breast cancer-like O-glycosylation produced in large amounts in Chinese-hamster ovary cells.

We have developed an expression system for the production of large quantities of recombinant MUC1 mucin in CHO-K1 (Chinese-hamster ovary K1) cells. The extracellular part of human MUC1, including 16 MUC1 tandem repeats, was produced as a fusion protein with murine IgG Fc, with an intervening enterokinase cleavage site for the removal of the Fc tail. Stable MUC1-IgG-producing CHO-K1 clones were generated and were found to secrete MUC1-IgG into the culture medium. After adaptation to suspension culture in protein-free medium in a bioreactor, the fusion protein was secreted in large quantities (100 mg/l per day) into the culture supernatant. From there, MUC1 could be purified to homogeneity using a two-step procedure including enterokinase cleavage and ion-exchange chromatography. Capillary liquid chromatography MS of released oligosaccharides from CHO-K1-produced MUC1 identified the main O-glycans as Galbeta1-3GalNAc (core 1) and mono- and di-sialylated core 1. The glycans occupied on average 4.3 of the five potential O-glycosylation sites in the tandem repeats, as determined by nano-liquid chromatography MS of partially deglycosylated Clostripain-digested protein. A very similar O-glycan profile and site occupancy was found in MUC1-IgG produced in the breast carcinoma cell line T47D, which has O-glycosylation typical for breast cancer. In contrast, MUC1-IgG produced in another breast cancer cell line, MCF-7, showed a more complex pattern with both core 1- and core 2-based O-glycans. This is the first reported production of large quantities of recombinant MUC1 with a breast cancer-like O-glycosylation that could be used for the immunotherapy of breast cancer.

Amino Acids↗
PubMed2003

Schizophrenic patients in different treatment settings during the era of deinstitutionalization: three-year follow-up of three discharge cohorts in Finland.

OBJECTIVE: We investigated differences in psychosocial and clinical characteristics, as well as the use of services, of schizophrenic patients in different treatment settings three years after their discharge from a psychiatric hospital. Furthermore, we examined secular changes in these phenomena during the era of rapid deinstitutionalization in Finland. METHOD: Three nationally representative samples comprised 3257 schizophrenic patients who had been discharged in 1986, 1990 and 1994. The patients were interviewed three years after discharge by each district's psychiatric professionals using a structured interview schedule specifically designed for the purposes of the present study. Psychosocial functioning was assessed on the Global Assessment Scale and on a modified version of the Medical Research Council Practices Profile. RESULTS: In the 1990s, more patients with a poor clinical and psychosocial state were transferred from hospital to alternative outpatient facilities, such as sheltered workshops or supported residences. In successive cohorts, the proportion of patients who had dropped out of treatment decreased and the psychiatric and somatic state of the drop-outs improved. CONCLUSION: In general, the psychiatric treatment system has worked well for most deinstitutionalized patients. In the future, however, it is important that the quality of care and adequate resources in the alternative outpatient facilities are ensured.

Adolescent↗
PubMed2003

The relationship of needs and quality of life in persons with schizophrenia living in the community. A Nordic multi-center study.

The relationship between needs for care and support and subjective quality of life was investigated in a cross-sectional multi-center study including 418 individuals with schizophrenia from 10 centers in Nordic countries. Needs in 22 domains were investigated by interviews with key workers and their patients using the Camberwell Assessment of Need scale, and quality of life by the Lancashire Quality of Life Profile. The results showed that key workers rated slightly more needs than patients. To have more unmet needs, as rated by both key workers and patients, were correlated to a worse overall subjective quality of life, while met needs showed no such association. A regression analysis, controlling for clinical and social characteristics of the patients, showed more unmet needs to be associated with a worse quality of life, accounting for 6% out of a total of 41% explained variance in subjective quality of life. Regression analyses of the relationship of unmet needs in specific life domains and overall quality of life showed that unmet needs in five domains as perceived by patients accounted for 17% of the explained variance in overall quality of life. More than half of this variance was related to an unmet need in the domain of social relationships. It is concluded that unmet needs are of specific importance in needs assessment and that attention must be paid to separate met needs for care and services from unmet needs, since the latter seem more important to consider in order to improve outcome of interventions with regard to quality of life. Specific attention should in this context also be paid to unmet needs concerning social relationships and problems with accommodation.

Adult↗
PubMed2002

The N terminus of the MUC2 mucin forms trimers that are held together within a trypsin-resistant core fragment.

The N terminus of the human MUC2 mucin (amino acids 1-1397) has been expressed as a recombinant tagged protein in Chinese hamster ovary cells. The intracellular form was found to be an endoglycosidase H-sensitive monomer, whereas the secreted form was an oligomer that gave monomers upon disulfide bond reduction. The secreted MUC2 N terminus contained a trypsin-resistant core fragment. Edman sequencing and mass spectrometry of the peptides obtained localized this core fragment to the C-terminal end of the recombinant protein. This core retained its oligomeric nature with an apparent mass of approximately 240 kDa. Upon reduction, peptides of approximately 85 kDa were found, suggesting that the N terminus forms trimers. This interpretation was also supported by gel electrophoresis and gel filtration of the intact MUC2 N terminus. Electron microscopy revealed three globular domains each linked via an extended and flexible region to a central part in a trefoil-like manner. Immunostaining with gold-labeled antibodies localized the N-terminal end to the three globular structures, and the antibodies directed against the Myc and green fluorescent protein tags attached at the C terminus localized these to the stalk side of the central trefoil. The N terminus of the MUC2 mucin is thus assembled into trimers that contain proteolytically stable parts, suggesting that MUC2 can only be partly degraded by intestinal proteases and thus is able to maintain a mucin network protecting the intestine.

Amino Acid Sequence↗
PubMed2002

Expressed emotion is not associated with disorder severity in first-episode mental disorder.

A family atmosphere characterized by expressed emotion (EE) is a robust predictor of clinical outcome of patients with schizophrenia and mood disorders. However, there is ongoing discussion as to whether EE is more a cause of clinical outcome or a parental reaction to disorder severity. This cross-sectional study examines a sample of 42 consecutive first-episode patients from a defined geographical area with severe mental disorders (schizophrenia-related disorders, psychotic mood disorders, and non-psychotic mood disorders). Their 42 relatives were interviewed, and the relationships between EE variables derived with the five-minute speech sample method (FMSS) and the patients' demographic, premorbid and clinical measures were analyzed. A high EE score was found in 40% of the relatives. High EE was associated with the interviewed relative's not being a spouse and the patient's being young and unmarried. It was not associated with premorbid characteristics, symptom dimensions or the diagnostic group of the patient. These results do not support the hypothesis that EE is a reaction to the clinical features of the patient. Instead, demographic factors may partly mediate the effect of EE on prognosis.

Adult↗
PubMed2002

Lactotetraosylceramide, a novel glycosphingolipid receptor for Helicobacter pylori, present in human gastric epithelium.

The binding of Helicobacter pylori to glycosphingolipids was examined by binding of (35)S-labeled bacteria to glycosphingolipids on thin-layer chromatograms. In addition to previously reported binding specificities, a selective binding to a non-acid tetraglycosylceramide of human meconium was found. This H. pylori binding glycosphingolipid was isolated and, on the basis of mass spectrometry, proton NMR spectroscopy, and degradation studies, were identified as Galbeta3GlcNAcbeta3Galbeta4Glcbeta1Cer (lactotetraosylceramide). When using non-acid glycosphingolipid preparations from human gastric epithelial cells, an identical binding of H. pylori to the tetraglycosylceramide interval was obtained in one of seven samples. Evidence for the presence of lactotetraosylceramide in the binding-active interval was obtained by proton NMR spectroscopy of intact glycosphingolipids and by gas chromatography-electron ionization mass spectrometry of permethylated tetrasaccharides obtained by ceramide glycanase hydrolysis. The lactotetraosylceramide binding property was detected in 65 of 74 H. pylori isolates (88%). Binding of H. pylori to lactotetraosylceramide on thin-layer chromatograms was inhibited by preincubation with lactotetraose but not with lactose. Removal of the terminal galactose of lactotetraosylceramide by galactosidase hydrolysis abolished the binding as did hydrazinolysis of the acetamido group of the N-acetylglucosamine. Therefore, Galbeta3GlcNAc is an essential part of the binding epitope.

Chromatography, Gas↗
PubMed2002

Two glycosylation alterations of mouse intestinal mucins due to infection caused by the parasite Nippostrongylus brasiliensis.

The glycosylation alterations of mouse small intestinal mucins during a 12-day infectious cycle caused by the parasite Nippostrongylus brasiliensis have been studied. The guanidinium chloride insoluble mucins were isolated at day 0 to 12 from the small intestine of infected and non-infected C57BL/6 mice. The O-linked oligosaccharides were released by reductive beta-elimination from the mucins and separated into neutral, sialylated and sulfated fractions. All fractions were analyzed by monosaccharide composition analysis and the neutral oligosaccharides were structurally characterized by gas chromatography/mass spectrometry. Two oligosaccharides containing blood group H-type epitopes (Fucalpha1-2Gal-) were transiently expressed with a maximum at day 6. Additional oligosaccharides with the common structure HexNAc-Gal-3GalNAcol were transiently induced with a maximum at day 10. Northern blot analysis on total RNA showed a transient expression at day 4-6 of the Fut2 gene encoding a Fucalpha1-2 fucosyltransferase, probably responsible for the detected blood group H-type epitopes. Comparisons with the corresponding infection in rat studied previously, revealed structurally different alterations, although occurring as transient events in both species. Both showed an induced blood group-type transferase halfway through the infection (a blood group A transferase in rat) and an induced transferase adding a terminal GalNAc (to a sialic acid- containing epitope in rat) towards the end of the infection. These differences between closely related species suggest rapid evolutionary alterations in glycosyltransferase expression.

Animals↗
PubMedDate not supplied

Cognitive functioning and expressed emotion among patients with first-episode severe psychiatric disorders.

Expressed emotion (EE) in families is able to predict the clinical outcome of patients with schizophrenia and mood disorders. However, the origins of EE and its interactions with the patient's clinical characteristics are not clear. In this respect, cognitive functioning of schizophrenic and mood-disorder patients has yielded contradictory results. In this cross-sectional study, we examined a sample of 42 consecutive first-episode patients with schizophrenia-related psychoses and severe mood disorders. Forty-two relatives were interviewed with the Five-Minute Speech Sample method. The relationships between EE and 3 clusters of patient-related variables (sociodemography, performance in cognitive tests, and psychopathology) were analyzed with stepwise regression analysis. With the exception of premorbid adjustment in childhood, only the cognitive variables were significantly associated with EE after controlling for the effect of the other variables. High EE was significantly associated with good performance in cognitive tests. Our results favor the attribution hypothesis of EE instead of the hypothesis that patient psychopathology would explain EE. Good cognitive functioning may lead to higher EE scores because of the higher expectations by the relatives.

Adult↗