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Biomedical subjects

R Carlsson

Publications and source records attributed to R Carlsson.

At least 19 recordsLinked to original sources

Neuropsychological functions predict 1- and 3-year outcome in first-episode psychosis.

OBJECTIVE: To examine neuropsychological performance as a possible predictor of course and outcome in first-episode psychotic (FEP) patients. METHOD: A group of consecutive FEP patients (n = 120) tested with Wechsler Adult Intelligence Scales-Revised (WAIS-R) at baseline was compared with a healthy group (n = 30) matched for age, education and gender. Relationship between WAIS-R and both Brief Psychiatric Rating Scale and Global Assessment of Function (GAF) ratings were studied at baseline and at 1- and 3-year follow-ups. RESULTS: The performance of FEP patients was significantly lower (P < 0.001) than that of healthy comparison subjects on all WAIS-R subtests except for Information and Comprehension. The WAIS-R scores of patients with schizophrenia syndromes (DSM-IV) were lower than those of patients with non-schizophrenia syndromes on Block Design. Low WAIS-R Full-Scale IQ scores in FEP patients predicted the presence of negative symptoms at 1-year follow-up and of low GAF ratings at 3-year follow-up. CONCLUSION: Neurocognitive performance at admission appears to predict various aspects of functional outcome in FEP.

Adolescent↗

Patients with ischemic heart disease: quality of life predicts long-term mortality.

OBJECTIVE: We have investigated whether perceived quality of life has an impact on long-term survival after a cardiac event. DESIGN: Male (n = 316) and female (n = 97) patients were assessed by means of a self-administered quality of life questionnaire 1 year after either acute myocardial infarction (n = 296), coronary artery bypass grafting surgery (n = 99) or percutaneous coronary intervention (n = 18). Inclusion period was 1989-1991. Ten years after the last patient answered the 1-year questionnaire, mortality (status factor) up to census date was analysed using nine dimensions of quality of life as covariates (Cox regression). RESULTS: At 1-year assessment, subjective general health (RR = 3.15), perceived arrhythmia (RR = 1.72), experience of sex life (RR = 1.55), perceived breathlessness (RR = 1.50) and experience of self-esteem (RR = 1.48) were all significantly related to death within the period up to census date. CONCLUSION: The findings highlight that the patients' own experience of his or her quality of life, has a prognostic importance for long-term mortality after a cardiac event. Clinicians should be aware that a careful monitoring of perceived quality of life is an important part of good patient care.

Adaptation, Physiological↗

Valid symptom reporting at upper endoscopy in a random sample of the Swedish adult general population: the Kalixanda study.

BACKGROUND: Upper oesophagogastroduodenoscopy is considered to be the gold standard for upper gastrointestinal disease assessment, but is currently seldom used in epidemiological studies. One concern is that the procedure may bias sampling among volunteers in a general adult population. The aim of this study was to explore whether the procedure affects symptom reporting. METHODS: A random sample of 3000 adults aged 20-81 years (mean age 50.4), from two Swedish municipalities (n=21,610) was surveyed using a validated postal questionnaire (the Abdominal Symptom Questionnaire) assessing gastrointestinal symptoms. A subsample of the responders was invited, in random order, to undergo an upper endoscopy and repeated symptom reporting using the same questionnaire, as well as a serology test for Helicobacter pylori. RESULTS: The response rate to the initial questionnaire was 74.2% and the participation rate for those eligible for the upper endoscopy was 73.3% (n = 1001, mean age 54.0 years, 48.8% male). No major social or symptom sampling error was encountered from the selection process, with the exception of an excess of symptom reporters among the youngest subjects. The prevalence of reflux symptoms, dyspeptic symptoms and irritable bowel symptoms was 40%, 37.6% and 29.6%, respectively, which is relatively high, but in no way extreme. CONCLUSIONS: The upper endoscopy survey strategy was successful. The response rate was high and there was no major selection bias of clinical relevance. The cohort selected for this study appears to be representative of the general Swedish adult population.

Adult↗

Effect of profound acid suppression in functional dyspepsia: a double-blind, randomized, placebo-controlled trial.

BACKGROUND: Functional dyspepsia (FD) is defined as persistent or recurrent pain/discomfort centred in the upper abdomen, where no structural explanation for the symptoms is found. The role of drug treatment remains controversial. The aim in this study was to evaluate the effect of omeprazole 20 mg twice daily (b.i.d) and to test methods for symptom assessment. METHODS: 197 patients fulfilling the criteria for FD were randomly allocated to double-blind treatment with omeprazole 20 mg b.i.d (n = 100) or placebo (n = 97) for 14 days. Patients with a known gastrointestinal disorder or with main symptoms indicating gastro-oesophageal reflux disease or irritable bowel syndrome were excluded. Helicobacter pylori testing and 24-h intra-oesophageal 24-h pH-metry were performed before randomization. The patients recorded dyspeptic symptoms on diary cards. RESULTS: A stringent endpoint, 'complete symptom relief on the last day of treatment', was the primary efficacy variable. For the APT cohort, this was achieved in 29.0% and 17.7% on omeprazole and placebo, respectively (95% CI of difference (11.3%): -0.4%-23.0%, P = 0.057). Similar figures in the PP cohort were 31.0% and 15.5%, respectively (95% Cl of difference (15.5%): 3.2%-27.7%, P = 0.018). The benefit of omeprazole in the PP cohort was confirmed by secondary endpoints such as, no dyspeptic symptoms on the last 2 days of treatment and overall treatment response. H. pylori status and the level of oesophageal acid exposure did not significantly influence the response to therapy. CONCLUSION: A subset of patients with FD will respond to therapy with omeprazole.

Adult↗

Self-administered symptom questionnaires in patients with dyspepsia and their yield in discriminating between endoscopic diagnoses.

BACKGROUND/AIMS: Symptoms are generally considered to be poor predictors of organic findings in patients with dyspepsia. We aimed at evaluating whether specific gastrointestinal symptoms, identified by self-administered questionnaires, correlate with specific endoscopic diagnoses and discriminate organic from functional dyspepsia. METHODS: Adult patients with pain or discomfort centred in the upper abdominal region were consecutively enrolled. Patients with heartburn, acid regurgitation, or defaecation and bowel habit problems as their predominant symptoms were excluded. Three self-administered questionnaires were applied before an oesophagogastroduodenoscopy was performed. RESULTS: Among the 799 patients, 50.6% had a normal endoscopy. Endoscopic diagnoses comprised: non-erosive oesophagitis (7.5%), erosive oesophagitis (11.1%), Barrett's oesophagus (1.1%), gastritis/duodenitis (8.4%), gastric ulcer (4.5%), duodenal ulcer (8.3%), and cancer (1.3%). Non-dominant heartburn and acid regurgitation were significantly more common in patients with organic dyspepsia, whereas hunger pains and rumbling occurred more often in those with functional dyspepsia. Multivariate analyses demonstrated that younger age, female gender, high scores for hunger pain, rumbling, hard stools, low scores for heartburn, and acid regurgitation predicted functional dyspepsia. CONCLUSIONS: Self-administered questionnaires revealed differences in the symptom patterns between patients with functional and organic dyspepsia. Furthermore, the health-related well-being in patients with functional and organic dyspepsia centred was impaired to the same extent.

Adolescent↗

Transcription factor AP-4 is a ligand for immunoglobulin-kappa promoter E-box elements.

Immunoglobulin (Ig)-kappa promoters from humans and mice share conserved sequences. The octamer element is common to all Ig promoters and pivotal for their function. However, other conserved sequence motifs, that differ between Ig variable gene families, are required for normal promoter function. These conserved motifs do not stimulate transcription in the absence of an octamer. One example is an E-box of the E47/E12 type (5'-CAGCTG-3'), which is found in all promoters of the human and murine Ig-kappa gene subgroups/families, with the exception of subgroups II and VI and their related murine families. In the present study we show that the ubiquitously expressed transcription factor AP-4, and not E47, interacts specifically with the kappa promoter E-boxes when tested in electrophoretic mobility-shift assays using nuclear extracts derived from human and murine B-cell lines. Furthermore, AP-4, unlike E47, did not act as a transactivator, which is in agreement with previous studies on intact kappa promoters, showing that transcription is absent when the octamer element has been mutated. Based on these data, and the conservation of the 5'-CAGCTG-3' motif among human and murine kappa promoters, we propose that AP-4 is the major ligand for Ig-kappa promoter E-boxes.

Animals↗

Human therapeutic antibodies.

The development of genetic engineering technologies has today advanced to the point where the generation of high-affinity human antibodies against therapeutic targets is not a major hurdle. Rather, it is the selection of target molecules in, for example, cancer therapy that poses a challenge. Targets that are not merely passive acceptors but those that signal into the cell are preferred. Recent advances in the clinical use of antibody-based therapy--such as anti-CD20 (rituximab) for the treatment of non-Hodgkin's lymphoma and anti-tumour-necrosis-factor-alpha for Crohn's disease--as well as novel antibody designs and improved understanding of the mode of action of current antibodies lend great hope to the future of this therapeutic approach.

Antibodies↗

A central core structure in an antibody variable domain determines antigen specificity.

Antibody binding sites provide an adaptable surface capable of interacting with essentially any molecular target. Using CDR shuffling, residues important for the assembly of mucin-1 specific paratopes were defined by random recombination of the complementarity determining regions derived from a set of mucin-1 specific clones, previously selected from an antibody fragment library. It was found that positions 33 and 50 in the heavy chain and 32, 34, 90, 91 and 96 in the light chain were conserved in many of the clones. These particular residues seem to be located centrally in the binding site as indicated by a structure model analysis. The importance of several of these conserved residues was supported by their presence in a mouse monoclonal antibody with a known structure and the same epitope specificity. Several of these corresponding residues in the mouse monoclonal antibody are known to interact with the antigen. In conclusion, critical residues important for maintaining a human antigen-specific binding site during the process of in vitro antibody evolution were defined. Furthermore, an explanation for the observed restricted germline gene usage in certain antibody responses against protein epitopes is provided.

Animals↗

Initial validation of a diagnostic questionnaire for gastroesophageal reflux disease.

OBJECTIVES: Brief, reliable, and valid self-administered questionnaires could facilitate the diagnosis of gastroesophageal reflux disease in primary care. We report the development and validation of such an instrument. METHODS: Content validity was informed by literature review, expert opinion, and cognitive interviewing of 50 patients resulting in a 22-item survey. For psychometric analyses, primary care patients completed the new questionnaire at enrollment and at intervals ranging from 3 days to 3 wk. Multitrait scaling, test-retest reliability, and responsiveness were assessed. Predictive validity analyses of all scales and items used specialty physician diagnosis as the "gold standard." RESULTS: Iterative factor analyses yielded three scales of four items each including heartburn, acid regurgitation, and dyspepsia. Multitrait scaling criteria including internal consistency, item interval consistency, and item discrimination were 100% satisfied. Test-retest reliability was high in those reporting stable symptoms. Scale scores significantly changed in those reporting a global change. Regressing specialty physician diagnosis on the three scales revealed significant effects for two scales (heartburn and regurgitation). Combining the two significant scales enhanced the strength of the model. Symptom response to self-directed treatment with nonprescription antisecretory medications was highly predictive of the diagnosis also, although the item demonstrated poor validity and reliability. CONCLUSIONS: A brief, simple 12-item questionnaire demonstrated validity and reliability and seemed to be responsive to change for reflux and dyspeptic symptoms.

Adult↗

Long-term effects on cholesterol levels and the utilization of lipid-lowering drugs of a hospital-based programme for secondary prevention of coronary artery disease.

BACKGROUND: The study was designed to determine whether a 1-year hospital-based secondary prevention programme would have any long-term effects on serum lipid levels and the use of lipid-lowering drugs in patients with coronary artery disease 4 years after referral to primary care facilities for follow-up. DESIGN/METHODS: After acute myocardial infarction or coronary bypass surgery, 241 consecutive patients were randomly assigned to conventional care (CC) by the primary health care facilities or to a 1-year hospital-based secondary prevention programme (SPP) with target levels for serum cholesterol (< 5.2 mmol/l) and triglycerides (< 1.5 mmol/l). After 1 year all patients were referred to the primary care sector for a further 4-year follow-up. RESULTS: At the 1-year follow-up there was a significant decrease in serum cholesterol, LDL-cholesterol and triglyceride levels in the SPP group but no change in the CC group, and lipid-lowering drugs were used more frequently in the SPP group. These changes were maintained after 5 years. The proportion of patients achieving target serum cholesterol and triglyceride levels were larger in the SPP group. CONCLUSIONS: Initiatives regarding cholesterol lowering and drug treatment taken by specialists within a structured hospital-based SPP have long-term impact. Accordingly, drug treatment should be initiated and adjusted to adequate doses before patients are referred to primary care for follow-up.

Aged↗

n-CoDeR concept: unique types of antibodies for diagnostic use and therapy.

The n-CoDeR recombinant antibody gene libraries are built on a single master framework, into which diverse in vivo-formed complementarity determining regions (CDRs) are allowed to recombine. These CDRs are sampled from in vivo-processed and proof-read gene sequences, thus ensuring an optimal level of correctly folded and functional molecules. By the modularized assembly process, up to six CDRs can be varied at the same time, providing a possibility for the creation of a hitherto undescribed genetic and functional variation. The n-CoDeR antibody gene libraries can be used to select highly specific, human antibody fragments with specificities to virtually any antigen, including carbohydrates and human self-proteins and with affinities down into the subnanomolar range. Furthermore, combining CDRs sampled from in vivo-processed sequences into a single framework result in molecules exhibiting a lower immunogenicity compared to normal human immunoglobulins, as determined by computer analyses. The distinguished features of the n-CoDeR libraries in the therapeutic and diagnostic areas are discussed.

Animals↗

The immune diversity in a test tube--non-immunised antibody libraries and functional variability in defined protein scaffolds.

Technologies to develop and evolve the function of proteins and, in particular, antibodies have developed rapidly since the introduction of phage display. Importantly, it has become possible to identify molecules with binding properties that cannot be found by other means. A range of different approaches to create general libraries that are useful for the selection of such molecules specific for essentially any kind of target have emerged. We herein review some of the most prominent approaches in the field and in particular discuss specific features related to the development of antibody libraries based on single antibody framework scaffolds. This approach not only permits identification of a range of specific binders, but also facilitates further evolution of initially derived molecules into molecules with optimised functions.

Antibodies↗

Recombining germline-derived CDR sequences for creating diverse single-framework antibody libraries.

We constructed a single-chain Fv antibody library that permits human complementarity-determining region (CDR) gene fragments of any germline to be incorporated combinatorially into the appropriate positions of the variable-region frameworks VH-DP47 and VL-DPL3. A library of 2 x 109 independent transformants was screened against haptens, peptides, carbohydrates, and proteins, and the selected antibody fragments exhibited dissociation constants in the subnanomolar range. The antibody genes in this library were built on a single master framework into which diverse CDRs were allowed to recombine. These CDRs were sampled from in vivo-processed gene sequences, thus potentially optimizing the levels of correctly folded and functional molecules, and resulting in a molecule exhibiting a lower computed immunogenicity compared to naive immunoglobulins. Using the modularized assembly process to incorporate foreign sequences into an immunoglobulin scaffold, it is possible to vary as many as six CDRs at the same time, creating genetic and functional variation in antibody molecules.

Germ-Line Mutation↗

Signals sustaining human immunoglobulin V gene hypermutation in isolated germinal centre B cells.

Affinity maturation of antibody responses depends on somatic hypermutation of the immunoglobulin V genes. Hypermutation is initiated specifically in proliferating B cells in lymphoid germinal centres but the signals driving this process remain unknown. This study identifies signals that promote V gene mutation in human germinal centre (GC) B cells in vitro. Single GC B cells were cultured by limiting dilution to allow detection of mutations arising during proliferation in vitro. Cells were first cultured in the presence of CD32L cell transfectants and CD40 antibody (the 'CD40 system') supplemented with combinations of cytokines capable of supporting similar levels of CD40-dependent GC B-cell growth [interleukin (IL)-10 + IL-1beta + IL-2 and IL-10 + IL-7 + IL-4]. Components of the 'EL4 system' were then added to drive differentiation, providing sufficient immunoglobulin mRNA for analysis. Analysis of VH3 genes from cultured cells by reverse transcription-polymerase chain reaction (RT-PCR)-based single-strand conformation polymorphism indicated that the combination IL-10 + IL-1beta + IL-2 promoted active V gene mutation whereas IL-10 + IL-7 + IL-4 was ineffective. This was confirmed by sequencing which also revealed that the de novo generated mutations were located in framework and complementarity-determining regions and shared characteristics with those arising in vivo. Somatic mutation in the target GC B-cell population may therefore be actively cytokine driven and not simply a consequence of continued proliferation. The experimental approach we describe should facilitate further studies of the mechanisms underlying V gene hypermutation.

B-Lymphocytes↗

Endoscopy-negative reflux disease.

The majority of patients with symptoms of gastro-oesophageal reflux have no endoscopic evidence of oesophagitis. There has been remarkably little systematic gathering of information about this group of patients. It is commonly believed that they have a mild form of reflux disease, with low levels of dysfunction that usually respond to simple therapeutic measures. Emerging data from recent studies indicate that this is not the case. Endoscopy-negative patients have symptom severities comparable to those with erosive disease, and which significantly impair their quality of life. The limited data available on the pathophysiology of endoscopy-negative reflux disease suggest that, in the majority of patients, it is as much a disease of excessive gastro-oesophageal reflux as it is in patients with oesophageal lesions. The same principles that apply to successful treatment in patients with oesophagitis also hold true for patients with endoscopy-negative disease.

Anti-Ulcer Agents↗

Complementarity-determining region (CDR) implantation: a theme of recombination.

A novel technology in the area of antibody engineering has been developed which allows for the creation of new types of antibody molecules. It is called complementarity-determining region (CDR) implantation and permits the random combination of CDR sequences formed in vivo into a single master framework. Thus, totally new gene combinations can be produced and used in selection processes. The result is a genetic variability which is extremely large, even exceeding the natural variability found in the immune system. In this commentary, CDR implantation is presented and the technology is discussed.

Animals↗

On demand therapy with omeprazole for the long-term management of patients with heartburn without oesophagitis--a placebo-controlled randomized trial.

AIM: To observe the natural course of gastro-oesophageal reflux disease (GERD) in patients without oesophagitis following effective symptom relief, and to determine the place of acid pump inhibitor therapy in the long-term management of these patients. METHODS: We investigated the efficacy of on-demand therapy with omeprazole 20 mg or 10 mg, or placebo in a double-blind, randomized multicentre trial. It involved 424 patients with troublesome heartburn without endoscopic evidence of oesophagitis in whom heartburn had been resolved with short-term treatment. Patients were told to take study medication on demand once daily on recurrence of symptoms until symptoms resolved over a 6-month period. They also had access to antacids. The primary efficacy variable was time to discontinuation of treatment, due to unwillingness to continue. RESULTS: According to life-table analysis, after 6 months the remission rates were 83% (95% CI: 77-89%) with omeprazole 20 mg, 69% (61-77%) with omeprazole 10 mg, and 56% (46-64%) with placebo (P < 0.01 for all intergroup differences). The mean (s.d.) number of study medications used per day in these groups was 0.43 (0.27), 0.41 (0.27) and 0.47 (0.27), respectively. The use of antacids was highest in the placebo group and lowest in the omeprazole 20 mg group. Treatment failure was associated with more than a doubling of antacid use, and a deterioration in patient quality of life. CONCLUSIONS: Approximately 50% of patients with heartburn who do not have oesophagitis need acid inhibitory therapy in addition to antacid medication to maintain a normal quality of life. On-demand therapy with omeprazole 20 mg, is an effective treatment strategy in these patients.

Adult↗