Vaccine protection in the elderly: are Austrian seniors adequately protected by vaccinations?

OBJECTIVE: The aim of the study was to evaluate, if elderly persons are sufficiently protected against infectious diseases by vaccination. PROBANDS AND METHODS: 300 elderly (> 60 years) and 300 young (< 35 years) persons from five Austrian cities were recruited according to the criteria of a field study. Antibody concentrations against tetanus, diphtheria, tickborne encephalitis and influenza were assessed by ELISA or by haemagglutination inhibition test. Disease and vaccination histories were recorded. RESULTS: The results of the study demonstrate that protection against infectious diseases was frequently insufficient in the elderly. This was partly due to the fact that old persons were not vaccinated according to recommended strategies. However, low antibody concentration and a short duration of protective humoral immunity were also observed in many elderly persons in spite of regular vaccination. This was not only the case in frail, but also in healthy elderlies. CONCLUSION: The data demonstrate that vaccination has a relatively weak and short-lasting effect in old age. The results of the study should stimulate discussions about strategies how vaccinations can be made more effective in old age. Improved campaigns, shortened vaccination intervals as well as the design of novel vaccines tailored to fulfill the specific demands of the aging immune system are imaginable.     

Polynomial-time quantum algorithm for the simulation of chemical dynamics

The computational cost of exact methods for quantum simulation using classical computers grows exponentially with system size. As a consequence, these techniques can be applied only to small systems. By contrast, we demonstrate that quantum computers could exactly simulate chemical reactions in polynomial time. Our algorithm uses the split-operator approach and explicitly simulates all electron-nuclear and interelectronic interactions in quadratic time. Surprisingly, this treatment is not only more accurate than the Born–Oppenheimer approximation but faster and more efficient as well, for all reactions with more than about four atoms. This is the case even though the entire electronic wave function is propagated on a grid with appropriately short time steps. Although the preparation and measurement of arbitrary states on a quantum computer is inefficient, here we demonstrate how to prepare states of chemical interest efficiently. We also show how to efficiently obtain chemically relevant observables, such as state-to-state transition probabilities and thermal reaction rates. Quantum computers using these techniques could outperform current classical computers with 100 qubits.     

Immunological features of nonimmunogenic hyperthyroidism

Blood lymphocyte subpopulations (Leu 4+ cells = pan-T cells, Leu 3a+ cells = helper/inducer cells, and Leu 2a+ cells = suppressor/cytotoxic cells), thyroid-stimulating immunoglobulins, microsomal antibodies and antibodies against thyroglobulin were determined in 10 patients with hyperthyroidism due to single autonomously functioning thyroid nodules (ATN), 11 patients with hyperthyroidism due to Graves' disease (GD) and in 20 normal subjects. Thyroidectomy was performed in 8 of the patients with ATN and in 6 of those with GD after 3 weeks of antithyroid drug treatment with methimazole. Lymphocytic infiltration of thyroid tissue, the amount of the various lymphocyte subsets (Leu 4+, Leu 3a+, and Leu 2a+ T cells as well as B+ B cells) in the thyroid gland, as well as the expression of the histocompatibility antigen HLA-DR on thyrocytes and intrathyroidal lymphocytes were examined. Blood Leu 4+ cells were reduced due to a lack of Leu 2a+ cells in patients with ATN and GD when compared to normal subjects. Thyroid-stimulating immunoglobulins were detected in all patients with ATN and GD, but in none of the normal subjects. Lymphocytic infiltration of thyroid tissue was present in patients with ATN and GD. The various lymphocyte subsets in the thyroid gland did not differ between the two patient groups. DR expression on thyrocytes was seen in 6 of the patients operated for ATN and in 5 of those who underwent surgery for GD. Infiltration with DR+-T lymphocytes was found in all thyroid glands investigated. Thus immunological findings usually classified as proof for the autoimmune origin of GD exist also in patients with ATN. An overlap in the pathogenetic background of both diseases seems possible.     

Analysis of intrathyroidal cytokine production in thyroid autoimmune disease: thyroid follicular cells produce interleukin-1 alpha and interleukin-6.

Cytokine production was studied in thyroid tissue from patients with Graves' disease, Hashimoto's thyroiditis and non-toxic goitre. The expression of interferon gamma, tumour necrosis factor alpha and beta, interleukin-1 alpha and beta, interleukin-6 and platelet-derived growth factor A chain was assessed by slot-blot analysis of the respective mRNA in freshly isolated tissue samples. All seven cytokines were detected in patients of all groups. Although the respective mRNA levels were, in general, higher in thyroid autoimmune disorders, this appeared to relate to the degree of the lymphocytic infiltration of the thyroid gland at the time of surgery. Purified thyroid follicular cells expressed high levels of interleukin-1 alpha and interleukin-6 mRNA and when established in primary culture, purified thyroid follicular cells from Graves' disease as well as non-toxic goitre produced interleukin-1 alpha and interleukin-6 bioactivity spontaneously. In the case of interleukin-1 this could be further augmented by addition of lipopolysaccharide to the thyroid follicular cell cultures. These results demonstrate that the lymphocytic infiltrate found in autoimmune and non-autoimmune thyroid disorders is associated with cytokine production. Additionally we have shown that intrathyroidal cytokine production is not restricted to thyroid-infiltrating mononuclear cells, but may also involve thyroid follicular cells both in vivo and in vitro. The cytokines produced by thyroid follicular cells may have an important role in stimulating autoantigen specific T cells in vivo as both interleukin-1 and interleukin-6 facilitate T cell activation.     

The prevalence of immunological abnormalities in endemic simple goitre

Thyroid growth stimulating immunoglobulins microsomal antibodies and antibodies against thyroglobulin were determined in patients with simple goitre (n = 20) and controls (n = 6) living in an iodine deficient area. In addition, lymphocytic infiltration of thyroid tissue, the amount of the various lymphocyte subsets (Leu 4+, Leu 3a+, and Leu 2a+ T-cells as well as B1+ B cells) in the thyroid gland, as well as the expression of the histocompatibility antigen HLA-DR on thyrocytes and intrathyroidal T-lymphocytes were examined. Goitrous patients were subdivided into two groups according to their individual iodine supply estimated by iodine excretion values, and immunological parameters were compared between patients with low (group A, iodine excretion less than 70 micrograms/24 h) and with higher (group B, iodine excretion greater than 100 micrograms/24 h) iodine supply. Thyroid growth stimulating immunoglobulins and antithyroid antibodies were equally prevalent in the two patient groups, but were absent in controls. Lymphocytic infiltration of thyroid tissue was present to a comparable extent in patients of groups A and B, but to a distinctly lower degree in control persons. Intrathyroidal T-lymphocyte subsets did not differ between patients and controls. B-lymphocytes, germinal centres as well as DR+ thyrocytes were detected in goitrous patients of both groups, but never in control persons. Thus, immunological abnormalities frequently occur in patients with simple goitre and do not depend upon individual iodine supply.     

Dynamic 123I-HDA myocardial scintigraphy after aortocoronary bypass grafting

In an attempt to evaluate the dynamics of fatty acid metabolism after aortocoronary bypass grafting (ACBG), ten patients were investigated after ACBG by ¹²³I-HDA myocardial scintigraphy. Tracer kinetics were followed for 90 min and compared to those of 36 nongrafted patients with different underlying heart diseases, including healthy volunteers. Regional analysis and monoexponential curve fitting were used to evaluate t _1/2 (half-life of the early period of tracer elimination); biexponential curve analysis was used to calculate Ca/Cb, the ratio of a fast and a slow component of tracer elimination. Rest and stress MUGA-RNV served as discriminating parameters to discern between patient groups with normal and abnormal ventricular function. Group I (normal controls) encompassed ten patients with normal ventricular function, including three after ACBG, and group II seven patients after ACBG and with abnormal ventricular function. Group III had coronary artery disease (CAD) documented by angiography, and group IV by prior myocardial infarction (MI). Group V included patients with cardiomyopathy (CMP). Regional analysis of group II revealed no significant differences to control regions (Gr I) for t _1/2 or Ca/Cb, but showed for Ca/Cb a nonsignificant shift toward group III values. However, group II differed significantly from group III and V. Three patients with normal ventricular function after ACBG showed elimination values that were all well within the range of completely normal individuals. Thus our data support the assumption that a normal function is indicative of a normal metabolism. Following myocardial fatty acid metabolism during rest might be a helpful noninvasive tool for etiologic differentiation of disturbed ventricular function.