A sensitive bioluminescent immunoinhibition test for CK-B subunit activity and a CK-MB specific ELISA compared: correlation with agarose electrophoresis and influence of CK-isoenzyme profile on results

Searching for alternatives to the imprecise spectrophotometric tests for low-concentration creatine kinase (EC 2.7.3.2) isoenzyme MB (CK-MB), we investigated the analytical performance of two potentially superior approaches--a bioluminescent immunoinhibition assay (I, LKB-Wallac) and an ELISA (enzyme-labeled immunosorbent assay) technique (II, Hybritech)--in comparison with an electrophoretic method (III, Beckman). Only I showed good between-day precision (CV 8.3%) at the upper reference limit, allowing reproducible assay of CK-B subunit activity down to at least 3 U/L. In conditions where CK isoenzyme assays remained unaffected by CK-MM concentrations, test results were proportional to the amount of CK-MB in the sample up to at least 50 U/L for I, 120 micrograms/L for II, and 100 U/L for III (r greater than 0.998 by linear regression analysis). For CK-MB-positive samples, the data by I correlated more closely with values by III (n = 24; r = 0.994) than did results by II (n = 15; r = 0.909), but both methods were equally effective in discriminating between samples with or without electrophoretically supranormal CK-MB activity (93% sensitivity). II was entirely CK-MB specific, whereas CK-B activity by I was consistently (18/18) increased in CK-MB-negative samples containing CK-BB (n = 6; r = 0.996) or macro CK, types 1 or 2 (n = 12; r = 0.930). I is highly sensitive for screening for increased non-MM CK activity, the nature of which should be subsequently clarified by electrophoresis.     

The CTLA-4 gene region of chromosome 2q33 is linked to, and associated with, type 1 diabetes. Belgian Diabetes Registry

Susceptibility to autoimmune insulin-dependent (type 1) diabetes mellitus is determined by a combination of environmental and genetic factors, which include variation in MHC genes on chromosome 6p21 (IDDM1) and the insulin gene on chromosome 11p15 (IDDM2). However, linkage to IDDM1 and IDDM2 cannot explain the clustering of type 1 diabetes in families, and a role for other genes is inferred. In the present report we describe linkage and association of type 1 diabetes to the CTLA-4 gene (cytotoxic T lymphocyte associated-4) on chromosome 2q33 (designated IDDM12). CTLA-4 is a strong candidate gene for T cell- mediated autoimmune disease because it encodes a T cell receptor that mediates T cell apoptosis and is a vital negative regulator of T cell activation. In addition, we provide supporting evidence that CTLA-4 is associated with susceptibility to Graves' disease, another organ- specific autoimmune disease.      

Agarose electrophoresis and inhibitor tests for isoamylase determination can give complementary clinical information

We report the presence of an extremely high proportion of "aged" amylase in the serum and cyst fluid of a patient with a pancreatic pseudocyst. A salivary amylase inhibitor test helped us to differentiate these "aged" pancreatic amylases from salivary fractions having a similar electrophoretic mobility.     

Interventions to enhance the Quality of Life of older people in residential long-term care: A systematic review

PurposeIn residential long-term care (LTC), a growing interest exists in the older residents’ Quality of Life (QoL). The Active Ageing-concept (AA) extended this focus, since AA has the aim to enhance QoL by optimising the opportunities for health, participation and security. In LTCs, AA can be outlined by 9 determinants. This systematic review aimed at identifying interventions to improve the QoL of LTC-residents. These interventions were organised according to the AA-determinants.MethodsPubMed, Web of Science, Psychinfo and Sociological Abstracts were screened systematically. Articles were excluded when they only concerned a specific group of LTC-residents.ResultsThirty five relevant articles, encompassing 3910 subjects were found. These concerned interventions concentrating on one or more of the 9 AA-determinants. The largest proportion of interventions regarded the physical activity level or the psychological factors of the residents. Overall, no systematic effects on QoL could be found and a low methodological quality was generally present.ConclusionCurrently, studies aimed at enhancing the QoL of older LTC-resident are limited and often directed to physical and psychological interventions. The lack of a systematic effect on QoL is possibly related to the fact that these interventions were often not multidimensional, whereas QoL is a multidimensional concept.     

An important minority of prediabetic first-degree relatives of type 1 diabetic patients derives from seroconversion to persistent autoantibody positivity after 10?years of age

Aims/hypothesis

The appearance of autoantibodies (Abs) before diabetes onset has mainly been studied in young children. However, most patients develop type 1 diabetes after the age of 15?years. In first-degree relatives aged under 40?years, we investigated the frequency of seroconversion to (persistent) Ab positivity, progression to diabetes and baseline characteristics of seroconverters according to age.

Methods

Abs against insulin (IAA), glutamate decarboxylase (GADA), insulinoma-associated protein 2 (IA-2A) and zinc transporter 8 (ZnT8A) were measured during follow-up of 7,170 first-degree relatives.

Results

We identified 379 (5.3%) relatives with positivity for IAA, GADA, IA-2A and/or ZnT8A (Ab⁺) at first sampling and 224 (3.1%) at a later time point. Most seroconversions occurred after the age of 10?years (63%). During follow-up, Abs persisted more often in relatives initially Ab⁺ (76%) than in seroconverters (53%; p?Conclusions/interpretation Seroconversion to (persistent) Ab⁺ occurs regardless of age. Although the progression rate to diabetes is higher under age 10?years, later seroconverters (up to age 40?years) have similar characteristics when compared with age-matched initially Ab⁺ relatives and generate an important minority of prediabetic relatives, warranting their identification and, eventually, enrolment in prevention trials.