T cells, natural killer cells, and γδT cells in a large patient cohort with rheumatoid arthritis: influence of age and anti-rheumatic therapy

Objective: The aim of this cohort study was to evaluate the distribution of natural killer (NK) cells and T-cell subsets, including γδT cells, in the peripheral blood of patients with rheumatoid arthritis (RA) in a large real-life patient cohort, taking into account the patients' demographics, disease characteristics, and anti-rheumatic therapy.Method: The study recruited 508 RA patients between November 2013 and August 2015. Lymphocyte differentiation using eight-colour flow cytometry (fluorescence-activated cell sorting) of the peripheral blood was performed for all patients. Clinical data, including age, gender, disease duration, serostatus, disease activity, antibody status, immunosuppressive therapy including use of different biological disease-modifying anti-rheumatic drugs (bDMARDs) and conventional synthetic DMARDs, were retrospectively assessed using electronic patient files. Multivariate regression analysis was performed to assess the effect of these variables on T-cell, NK-cell, and γδT-cell counts.Results: The median patient age was 61.0 years and 74.1% were female. The median disease duration of RA was 12.0 years. Median Disease Activity Score based on 28-joint count was 2.8 and 56.3% were treated with bDMARDs. There were no differences in immunosuppressive therapy between different age groups. While rituximab, abatacept, and tocilizumab had no influence on lymphocyte subdifferentiation, tumour necrosis factor (TNF) inhibitors and age significantly influenced the numbers of T cells, T-helper cells, T-NK cells, NK cells, and γδT cells.Conclusion: Age and TNF-inhibition therapy influence lymphocyte subdifferentiation in patients with RA. It may be prudent to use age- and therapy-adjusted standard values for lymphocyte subsets during clinical trials and treatment of RA.

Deformation Behavior of Polycrystalline MoSi2 Between 495°C and 1250°C

In order to study the deformation processes of reaction-sintered and hot pressed MoSi2, compression tests have been performed and the microstructure of the deformed samples has been investigated by optical, scanning and transmission electron microscopy. At a low strain rate of 2.5× 10−7 S−1 permanent deformation has been achieved at 1250°C. The deformation behaviour is controlled by different microprocesses within different temperature ranges. Below 1000°C, hardening occurs beyond the upper and lower yield points. Inside the grains, dislocations glide at sufficiently high stresses in a homogeneous way as well as in localized slip bands. A plateau in the dependence of the yield stress on temperaturecorresponds to the flow stress anomaly of easy slip systems in single crystals. However, since there are not enough independent slip systems to satisfy the van Mises criterion, the material does not deform homogeneously in all grains. Intergranular and intragranular cracks, which are formed after the yield point, carry an increasing part of strain at decreasing temperatures. Above 1000°C, softening occurs after the yield point. A grain boundary phase flows viscously and carries most of the deformation. Since the grains do not deform themselves, intergranular cracks develop also at high temperatures.

Control of a methicillin-resistant Staphylococcus aureus (MRSA) outbreak in a day-care institution

This article describes an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) in two institutions for multi-handicapped children in Copenhagen. The aim of the study was to determine whether it was possible to eradicate MRSA in a setting with multi-handicapped children and staff where there was a high degree of physical interaction. This was a prospective interventional uncontrolled cohort study that took place from January 2003 to March 2005. All individuals in close contact with the two institutions and/or in close contact with an MRSA-colonized subject from the outbreak were included in the study: 38 children, 60 staff members and 12 close relatives of colonized subjects. Infection control measures included screening all individuals. When MRSA infection or colonization was found, an attempt was made to eradicate MRSA, staff education was undertaken and attempts were made to determine the route of transmission. Eleven individuals were found to be positive for MRSA (10.0%). All isolates were identical by pulsed-field gel electrophoresis and harboured the staphylococcal cassette chromosome mec (SCCmec) type IV. All colonized and infected individuals were associated with a single room in one of the institutions. MRSA was eradicated from all the colonized and infected subjects. This study shows that it is possible to control an MRSA outbreak in institutions for multi-handicapped children where there is a high degree of physical contact.

[Serum enzymes in grade I hypertensive patients before and following a change in nutrition in relation to polyene acid and electrolyte content]

In patients with mild hypertension the blood pressure reduction through n-3 fatty acids can be improved by an additional increase of the potassium intake. Metabolic processes can be followed up by determinating serum enzymes. By an additional daily intake of 200 g fish for 14 days the metabolism is hardly changed. The increased activity of the transaminases after diet is probably a consequence of the increased protein intake.

[15N tracer technical studies of protein metabolism in arteriosclerosis patients]

The incorporation of the stable isotope 15N in plasma proteins and blood cells after oral application of 3 g 15NH4Cl (95 At% 15N) per 70 kg body weight was followed up in 11 patients with ischemic heart disease or peripheral arteriosclerosis and in 7 healthy control subjects. Preliminary results indicate that the turnover of plasma protein, especially fibrin, is elevated in patients with arteriosclerosis. Investigations of platelets intimate a decreased turnover of platelet protein in patients with arteriosclerosis as compared to control subjects. Possible reasons for these alterations are discussed.

[Enzyme liberation after electrical His bundle ablation]

The release of isoenzymes, i.e. aspartate aminotransferase (ASAT), lactic dehydrogenase (LDH), malic dehydrogenase (MDH), and of creatine kinase (CK) after electric His bundle ablation is presented. The enzyme release is increasing with the amount of energy applied during the intervention. Mitochondrial MDH and ASAT were found in six of the seven patients. Therefore, the size of myocardial necrosis by ablation can be estimated by the sequence of the release of the enzymes, and the isoenzymes, respectively.

[Changes in protein metabolism in arteriosclerosis patients]

The sequence of the incorporation of the stable isotope 15N in plasma protein and fibrinogen has been followed by an 15N labelling test in 11 patients with arteriosclerosis and a control group of 7 persons. The investigation showed a higher turnover of plasma protein and especially of fibrinogen in the patients with arteriosclerosis.

[Assessment of prognosis in acute myocardial infarct after reaching the maximum enzyme activity]

A new method is described for estimation of the prognosis of acute myocardial infarction progress due to temporary decrease in the isoenzymes, i.e. malic dehydrogenase (MDH), aspartate aminotransferase (ASAT), lactic dehydrogenase (LDH), and the decrease in the creatine kinase (CK). It is shown that the time of enzymatic activity is an essential factor. If 120 hours of decrease in enzymatic activity of MDH, LDH, and CK are exceeded, the prognosis of the myocardial infarction deteriorates dramatically.

[Malate dehydrogenase isoenzymes in myocardial infarction]

Plasma CPK activity and the activity of isoenzymes MDH, AST and LDH were assessed in 60 patients with myocardial infarction of different severity, with reference to the time since the onset of the attack. The peaks of CPK and MDH-C activity were reached sooner than those of LDH-M and AST-C, while the CPK and MDH-C curves were similar. The severity of the disease showed correlation to later onset of enzyme peaks and markedly delayed decrease in the respective values. Increased activity of mitochondrial isoenzymes and blood LDH-M provided additional information on the severity of the disease. Delayed normalization of these activities was associated with a poor diagnosis.