Identification of mucins using metabolic labeling, immunoprecipitation, and gel electrophoresis.
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Animals↗
Biomedical subjects
J Dekker
Publications and source records attributed to J Dekker.
Mucin precursors. Identification and analysis of their intracellular processing.
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Animals↗
Major depression, double depression and personality disorders.
Personality disorders are much more common among depressive patients than among normal people. Until now, little research has been conducted into the prevalence of personality disorders among patients with both major depression and dysthymia (double depression). The subject of this study is whether depressive patients with dysthymia have more personality disorders than those with no dysthymia. The Vragenlijst voor Kenmerken van de Persoonlijkheid (a Dutch self-report based on the International Personality Disorder Examination) was completed for 211 outpatients with major depression. Approximately 60% of the patients suffer from one or more personality disorders. Depressive patients with dysthymia differ little from the patients without dysthymia, but patients with dysthymia have more cluster A disorders and are more avoidant. Depressive patients without dysthymia do not differ from the patients with dysthymia in terms of symptoms. Depressive patients with personality disorders have significantly more symptoms than the patients without these disorders. There is no interaction between dysthymia and personality disorder.
Adult↗
Internal consistency and validity of an observational method for assessing disability in mobility in patients with osteoarthritis.
OBJECTIVE: To establish the internal consistency and validity of an observational method for assessing disability in mobility in patients with osteoarthritis (OA). METHODS: Data were obtained from 198 patients with OA of the hip or knee. Results of the observational method were compared with results of self-report methods (questionnaires) on disability in mobility. RESULTS: Both Cronbach's alpha and Mokken Scale Analysis indicate that the method is internally consistent. Using factor analysis, observed and self-reported disability in mobility were found to be closely associated and could not be differentiated. CONCLUSIONS: The observational method is internally consistent and indeed measures disability in mobility (high convergent validity), but observations and self-report seem to yield largely equivalent information (low divergent validity). This raises questions regarding the simultaneous use of both observational and self-report methods in the assessment of disability in mobility in OA patients.
Activities of Daily Living↗
Effectiveness of exercise therapy in patients with osteoarthritis of the hip or knee: a systematic review of randomized clinical trials.
OBJECTIVE: To review the effectiveness of exercise therapy in patients with osteoarthritis (OA) of the hip or knee. METHODS: A computerized literature search of Medline, Embase, and Cinahl was carried out. Randomized clinical trials on exercise therapy for OA of the hip or knee were selected if treatment had been randomly allocated and if pain, self-reported disability, observed disability, or patient's global assessment of effect had been used as outcome measures. The validity of trials was systematically assessed by independent reviewers. Effect sizes and power estimates were calculated. A best evidence synthesis was conducted, weighting the studies with respect to their validity and power. RESULTS: Six of the 11 assessed trials satisfied at least 50% of the validity criteria. Two trials had sufficient power to detect medium-sized effects. Effect sizes indicated small-to-moderate beneficial effects of exercise therapy on pain, small beneficial effects on both disability outcome measures, and moderate-to-great beneficial effects according to patient's global assessment of effect. CONCLUSION: There is evidence of beneficial effects of exercise therapy in patients with OA of the hip or knee. However, the small number of good studies restricts drawing firm conclusions.
Exercise Therapy↗
A diagnostic test for apraxia in stroke patients: internal consistency and diagnostic value.
The internal consistency and the diagnostic value of a test for apraxia in patients having had a stroke are presented. Results indicate that the items of the test form a strong and consistent scale: Cronbach's alpha as well as the results of a Mokken scale analysis present good reliability and good scalability. The diagnostic value of the test was determined by comparison of test results in three groups of patients: 44 stroke patients with apraxia (patients), 35 stroke patients without apraxia (patient controls), and 50 healthy nursing home residents with no history of stroke (normal controls). The diagnostic value is expressed by means of the sensitivity and specificity and the predictive value of the test. In addition, Receiver Operator Characteristics (ROC) curves are presented. The sensitivity and specificity of the apraxia test appear to be good: all values are higher than 80%. The test also has high predictive value. The ROC curves illustrate that the test is sufficiently discriminative to allow a differentiation between persons with apraxia and persons without apraxia.
Adult↗
Diffusion of a quality improvement programme among allied health professionals.
OBJECTIVE: To assess the diffusion of a quality improvement (QI) programme among allied health professions in The Netherlands. DESIGN: Descriptive study, based on a questionnaire distributed to allied health professionals; response rate, 63%. SETTINGS AND PARTICIPANTS: All subsectors in health care were covered, including primary care and institutional care. The participants were either salaried or self-employed in private practice. INTERVENTION: The governing boards of the professional associations developed a QI policy. This study reports the evaluation of the diffusion of this policy. MAIN OUTCOME MEASURE: Respondents' knowledge of the QI programme and their opinions with respect to the relevance of 15 QI activities. Respondents were asked whether they were currently taking part in QI activities and, if not, whether they intended to participate in them in the near future. In addition, the advantages of the QI programme and the barriers to further implementation which respondents perceived were assessed. RESULTS: Most of the health professionals were familiar with the QI programme. The relevance of the QI activities for the profession was rated. Continuing education was ranked highest in priority. The respondents perceived the advantages of many of the QI activities. At the time of the study, less than one-third of the respondents were taking part in peer review, or complying with national guidelines. Respondents listed a number of barriers to further implementation. CONCLUSIONS: The perceived advantages and barriers related to implementation appear to differ per QI activity. Consequently, implementation strategies should differ per QI activity and be tailored to the specific advantages and barriers of each one.
Allied Health Personnel↗
Podiatric care for diabetic patients with foot problems: an observational study.
The aims of this study were to describe podiatric care for diabetic patients with foot problems and to explore the changes in knowledge, self-care behaviour and physical functioning after podiatric care. The treatment characteristics of 26 diabetic patients referred to podiatry were assessed. Prior to the first podiatric visit (T1) and 20 weeks later (T2) these patients filled in a structured questionnaire and performed a six-minute walking test. In half the number of patients preventive goals were set and strived for by general education about the diabetic foot and advice on footwear and self-care behaviour. With regard to treatment, reduction of pain was the most frequently selected goal. To achieve this reduction, a variety of interventions was applied. After podiatric care, patients reported having less severe foot pain and some improvements in functional ability and self-care behaviour were found. This study offers clues to start controlled clinical trials on the effectiveness of podiatry for diabetic patients. Trials should not only be directed to (the role of podiatry in) ulcer healing; it may be even more significant to study its effectiveness for the purpose of prevention and treatment of early-stage diabetic foot symptoms.
Activities of Daily Living↗
Sulphation and secretion of the predominant secretory human colonic mucin MUC2 in ulcerative colitis.
BACKGROUND: Decreased synthesis of the predominant secretory human colonic mucin (MUC2) occurs during active ulcerative colitis. AIMS: To study possible alterations in mucin sulphation and mucin secretion, which could be the cause of decreased mucosal protection in ulcerative colitis. METHODS: Colonic biopsy specimens from patients with active ulcerative colitis, ulcerative colitis in remission, and controls were metabolically labelled with [35S]-amino acids or [35S]-sulphate, chase incubated and analysed by SDS-PAGE, followed by quantitation of mature [35S]-labelled MUC2. For quantitation of total MUC2, which includes non-radiolabelled and radiolabelled MUC2, dot blotting was performed, using a MUC2 monoclonal antibody. RESULTS: Between patient groups, no significant differences were found in [35S]-sulphate content of secreted MUC2 or in the secreted percentage of either [35S]-amino acid labelled MUC2 or total MUC2. During active ulcerative colitis, secretion of [35S]-sulphate labelled MUC2 was significantly increased twofold, whereas [35S]-sulphate incorporation into MUC2 was significantly reduced to half. CONCLUSIONS: During active ulcerative colitis, less MUC2 is secreted, because MUC2 synthesis is decreased while the secreted percentage of MUC2 is unaltered. Furthermore, sulphate content of secreted MUC2 is unaltered by a specific compensatory mechanism, because sulphated MUC2 is preferentially secreted while sulphate incorporation into MUC2 is reduced.
Adolescent↗
Gastrointestinal expression and partial cDNA cloning of murine Muc2.
To help us investigate the role of mucin in the protection of the colonic epithelium in the mouse, we aimed to identify the murine colonic mucin (MCM) and its encoding gene. We isolated MCM, raised an anti-MCM antiserum, and studied the biosynthesis of MCM in the gastrointestinal tract. Isolated MCM resembled other mucins in physicochemical properties. Anti-MCM recognized MCM as well as rat and human MUC2 on Western blots, interacting primarily with peptide epitopes, indicating that MCM was identical to murine Muc2. Using anti-MCM and previously characterized anti-human and anti-rat MUC2 antibodies, we identified a murine Muc2 precursor in the colon of approximately 600 kDa, which appeared similar in size to rat and human MUC2 precursors. Western blotting, immunoprecipitation of metabolically labeled mucins, and immunohistochemistry showed that murine Muc2 was expressed in the colon and the small intestine but was absent in the stomach. To independently identify murine Muc2, we cloned a cDNA fragment from murine colonic mRNA, encoding the 302 NH2-terminal amino acids of murine Muc2. The NH2 terminus of murine Muc2 showed 86 and 75% identity to the corresponding rat and human MUC2 peptide sequences, respectively. Northern blotting with a murine Muc2 cDNA probe showed hybridization to a very large mRNA, which was expressed highly in the colon and to some extend in the small intestine but was absent in the stomach. In situ hybridization showed that the murine Muc2 mRNA was confined to intestinal goblet cells. In conclusion, by two independent sets of experiments we identified murine Muc2, which appears homologous to rat and human MUC2. Because Muc2 is prominently expressed in the colon, it is most likely to be the predominant mucin in the colonic mucus layer.
Amino Acid Sequence↗
Strategic biochemical analysis of mucins.
MUC-type mucins comprise a family of structurally related molecules, which are expressed in epithelia of the body that are in close contact with the milieu. Because of their large sizes and very complex structures, containing very extensive O-glycosylation, MUC-type mucins are difficult to study by conventional techniques. Many see MUC-type mucins as protective molecules; however, functional studies on the individual MUC-type mucins are very scarce. At present, essential steps in MUC research are to characterize the specific expression patterns of each MUC-type mucin in the body and to find methods to reliably quantify these MUC-type mucins. These aims can only be met at the level of the primary sequences of the MUC-type mucins, as the O-glycosylation even within one species of MUC-type mucin is not only very complex, but may also vary among individuals, organs, and cell types. We will discuss some recent advances in mucin research, particularly the identification of MUC precursor molecules in metabolic labeling experiments. We will try to define some strategic considerations in the study of the expression patterns of MUC-type mucins, which circumvent the complications caused by the very complex and heterogeneous O-glycosylation of the molecules.
Amino Acid Sequence↗
Molecular cloning of human gastric mucin MUC5AC reveals conserved cysteine-rich D-domains and a putative leucine zipper motif.
To further clone the human gastric mucin MUC5AC cDNA, we screened a human gastric cDNA library with previously identified MUC5AC sequences. We obtained 32 independent clones encoding newly identified sequences comprising the entire N-terminal sequence of MUC5AC, up to 3024 bp upstream of the previously identified MUC5AC sequences. The N-terminus of MUC5AC shows high homology (43% identity) with the N-terminus of MUC2 and contains three domains homologous to the D-domains found in the pro-von Willebrand factor. Furthermore, the N-terminus of MUC5AC contains a putative leucine zipper motif not found in any other mucin identified so far. Moreover, a large central repetitive sequence was identified encoding approximately 2500 amino acids (7.5 kb). We were able to establish that the MUC5AC cDNA together with the previously identified 6.1 kb of MUC5AC cDNA sequence is about 16.6 kb, encoding 5525 amino acids. A model of the domain structure of MUC5AC is presented.
Amino Acid Sequence↗
ATP-independent DNA unwinding by the adenovirus single-stranded DNA binding protein requires a flexible DNA binding loop.
The adenovirus DNA binding protein (DBP) binds cooperatively to single-stranded (ss) DNA and stimulates both initiation and elongation of DNA replication. DBP forms protein filaments via a C-terminal arm that hooks into a neighbouring molecule. This multimerization is the driving force for ATP-independent DNA unwinding by DBP during elongation. Another conserved part of DBP forms an unstructured flexible loop that is probably directly involved in contacting DNA. By making appropriate deletion mutants that do not distort the overall DBP structure, the influence of the C-terminal arm and the flexible loop on the kinetics of ssDNA binding and on DNA replication was studied. Employing surface plasmon resonance we show that both parts of the protein are required for high affinity binding. Deletion of the C-terminal arm leads to an extremely labile DBP-ssDNA complex indicating the importance of multimerization. The flexible loop is also required for optimal stability of the DBP-ssDNA complex, providing additional evidence that this region forms part of the ssDNA-binding surface of DBP. Both deletion mutants are still able to stimulate initiation of DNA replication but are defective in supporting elongation, which may be caused by the fact that both mutants have a reduced DNA unwinding activity. Surprisingly, mixtures containing both mutants do stimulate elongation. Mixing the purified mutant proteins leads to the formation of mixed filaments that have a higher affinity for ssDNA than homogeneous mutant filaments. These results provide evidence that the C-terminal arm and the flexible loop have distinct functions in unwinding during replication. We propose the following model for ATP-independent DNA unwinding by DBP. Multimerization via the C-terminal arm is required for the formation of a protein filament that saturates the displaced strand. A high affinity of a DBP monomer for ssDNA and subsequent local destabilization of the replication fork requires the flexible loop.
Adenosine Triphosphate↗
Validity of Cyriax's concept capsular pattern for the diagnosis of osteoarthritis of hip and/or knee.
To analyse the validity of Cyriax's concept of the "capsular pattern" in the diagnosis of osteoarthritis (OA) of hip and knee, data on 200 patients were analysed. The capsular pattern with limitations of medial rotation, flexion, and abduction, was not present as a distinct pattern in patients with OA of the hip. In patients with OA of the knee, an indication of the existence of a capsular pattern of the knee, with limited ranges of motion for both flexion and extension was found in subgroups of patients. It is concluded that the capsular pattern cannot be regarded as a valid test for the diagnosis of OA of the hip or knee. Further investigations in subgroups of patients are recommended.
Aged↗
The oligomerization of a family of four genetically clustered human gastrointestinal mucins.
Mucins are synthesized and secreted by many epithelia. They are complex glycoproteins that offer cytoprotection. In their functional configuration, mucins form oligomers by a biosynthetic process that is poorly understood. A family of four human gastrointestinal mucin genes (MUC2, MUC5AC, MUC5B, and MUC6) is clustered to chromosome 11p15.5. To study oligomerization of these related mucins, we performed metabolic labeling experiments with [35S]amino acids in LS174T cells, and isolated mucin precursors by specific immunoprecipitations that were analyzed on SDS-PAGE. Each of the precursors of MUC2, MUC5AC, MUC5B, and MUC6 formed a single species of disulfide-linked homo-oligomer within 1 h after pulse labeling. Based on apparent molecular masses, these oligomeric precursors were most likely dimers. Inhibition of vesicular RER-to-Golgi transport, with brefeldin A and CCCP, did not affect the dimerization of MUC2 precursors, localizing dimerization to the RER. O-Glycosylation of MUC2 followed dimerization. Inhibition of N-glycosylation by tunicamycin retarded, but did not inhibit, dimerization, indicating that N-glycans play a role in efficient dimerization of MUC2 precursors. Based on sequence homology, the ability of MUC2, MUC5AC, MUC5B and MUC6 to dimerize most likely resides in their C-terminal domains. Thus, the RER-localized dimerization of secretory mucins likely proceeds by similar mechanisms, which is an essential step in the formation of the human gastrointestinal mucus-gels.
Cell Line↗
A survey of physical therapy goals and interventions for patients with back and knee pain.
BACKGROUND AND PURPOSE: The physical therapy management of patients with pain often lacks a theoretical or conceptual basis. The purpose of this study was to compare treatments of patients with back and knee pain with a treatment framework (conceptual model) that we developed. This framework emphasizes physiological recovery, or reduction of impairments (eg, reduction of swelling), followed by emphasis on the reduction of disabilities. Expectations were derived concerning treatment goals and interventions in the course of treatment. SUBJECTS: Patients with back pain (n = 1,085) and patients with knee trauma (n = 416) were treated by 83 Dutch physical therapists. METHODS: Survey data were gathered on impairments and disabilities and on treatment goals and interventions. RESULTS: For both groups of patients, two out of a maximum of eight treatment goals were directed at alleviating impairments in accordance with the framework. Goals directed toward the alleviation of disabilities did not show a similar relationship to the framework. For two treatment goals, the course of treatment was in accordance with the framework for both groups of patients. CONCLUSION AND DISCUSSION: The framework is only partially reflected in Dutch physical therapist practice. The use of such a framework, however, may be a helpful tool in gaining more insight into physical therapy in daily practice.
Activities of Daily Living↗
The use of therapeutic ultrasound by physical therapists in Dutch primary health care.
BACKGROUND AND PURPOSE: The purposes of this study were to describe the use of ultrasound by Dutch physical therapists and to address the question of whether this use is what would be considered correct. SUBJECTS AND METHODS: Physical therapists in the Dutch primary health care system gathered data on 17,201 patients, addressing reasons for referral, treatment goals (in terms of impairments and disabilities), and physical therapy interventions. Patients treated with ultrasound (n = 3,959) were compared with a reference group of patients who were not treated with ultrasound (n = 13,242). RESULTS: Physical therapists applied ultrasound for soft tissue injuries of recent onset, mainly aiming to reduce pain and swelling. Ultrasound was used in all phases of treatment and was not restricted to the first 3 weeks of treatment. Ultrasound was combined relatively infrequently with exercise and relatively frequently with massage. CONCLUSION AND DISCUSSION: Regarding the indications for referral and treatment goals chosen, the actual use of ultrasound corresponds to assumptions about expected use. The timing of its application and the combination with other forms of therapy do not correspond in all aspects to the assumptions made.
Adolescent↗
Pediatric duodenal biopsies: mucosal morphology and glycohydrolase expression do not change along the duodenum.
BACKGROUND: Duodenal mucosal biopsies are routinely taken for diagnosis in children with complaints of the upper gastrointestinal tract. Surprisingly, little is known about the usefulness of proximal duodenal versus distal duodenal biopsies for routine diagnostic purposes. This study evaluated the comparability of proximal and distal duodenal biopsies with respect to mucosal morphology as well as glycohydrolase expression as an indicator of intestinal epithelial function. METHODS: Specimens obtained in duodenal endoscopic biopsies from 64 children, ranging in age from 3 months to 18 years with normal or affected mucosa, were studied. Biopsies were performed in anatomically defined regions in the bulbus duodeni (the very proximal part of the duodenum) and distally of the papilla of Vater (distal of the pancreatic duct). Biopsy specimens were paraformaldehyde-fixed for histologic examination and immunohistochemical evaluation or were homogenized to isolate RNA. Crypt/villus morphology was assessed as is routinely determined by pathologists. In addition, several aspects of lactase and sucrase-isomaltase expression as paradigms of intestinal brush border enzymes were assessed: localization at the cellular level, semiquantitative immunohistochemistry, and quantitative measurement of the messenger RNA levels of the respective brush border glycohydrolases. RESULTS: As anticipated, there was a wide interpatient variation in mucosal morphology and expression of lactase and sucrase-isomaltase. Nonetheless, the consistent finding was that in each patient, measurements of morphology and lactase and sucrase-isomaltase gene expression were very similar between samples obtained in the proximal and distal biopsies. CONCLUSIONS: Biopsies performed in either location in the duodenum are equally suitable for diagnostic workup of patients suspected of mucosal abnormalities affecting morphology or small intestinal brush border glycohydrolase activities.
Adolescent↗