Amyloid PET imaging in cardiac amyloidosis: a pilot study using 18F-flutemetamol positron emission tomography

Annals of Nuclear Medicine - Cardiac amyloidosis is a rare disease characterized by amyloid heart deposits and is usually a part of systemic amyloidosis, in relation to systemic light chain (AL)...     

The Essential Oil of Thymus serpylloides ssp. gadorensis

THYMUS SERPYLLOIDES ssp. GADORENSIS is endemic in the Betic region (Spain). Gas chromatography and GC/mass spectrometry studies of its essential oil showed its major components to be carvacrol and its biosynthetic precursors (gamma-terpinene and P-cymene).     

Autoantibodies to heat shock protein 90 in the human natural antibody repertoire

The present study demonstrates the presence of natural autoantibodies of the IgG isotype directed against heat shock protein 90 (HSP90). The binding properties of affinity-purified anti-HSP antibodies were compared with those of natural antibodies specific for other self antigens, including anti-thyroglobulin and anti-myoglobin autoantibodies, by using semiquantitative immunoblotting, with solubilized proteins from normal liver tissue as antigens, and cross-blot analysis using purified self proteins. Affinity-purified anti-HSP90 antibodies were polyreactive and the non-HSP90-specific fraction of normal IgG was depleted in its natural autoantibody content. We further observed that self antigens including HSP, myosin, tubulin and aldolase with highly conserved structures show similar patterns of binding with natural antibodies, and form a well-defined cluster as demonstrated by cluster analysis of immunoreactivity data, whereas the less-conserved self and non-self antigens remained unclustered. The results favor the hypothesis that HSP90 belongs to a subset of highly conserved and immunodominant self antigens that are the primary target for natural autoantibodies in normal human IgG.     

Does resistance to pyrazinamide accurately indicate the presence of Mycobacterium bovis?

Mycobacterium bovis is best identified by screening those isolates of the Mycobacterium tuberculosis complex that have any pyrazinamide (PZA) resistance, using a confirmatory test such as spoligotyping, biochemical testing, or genomic deletion analysis. The sensitivity for detection of M. bovis is lowered to 82% when only PZA-monoresistant isolates are screened.     

Hearing impairment as an early sign of alpha‐mannosidosis in children with a mild phenotype: Report of seven new cases

Alpha‐mannosidosis (AM) is a very rare (prevalence: 1/500000 births) autosomal recessive lysosomal storage disorder. It is characterized by multi‐systemic involvement associated with progressive intellectual disability, hearing loss, skeletal anomalies, and coarse facial features. The spectrum is wide, from very severe and lethal to a milder phenotype that usually progresses slowly. AM is caused by a deficiency of lysosomal alpha‐mannosidase. A diagnosis can be established by measuring the activity of lysosomal alpha‐mannosidase in leucocytes and screening for abnormal urinary excretion of mannose‐rich oligosaccharides. Genetic confirmation is obtained with the identification of MAN2B1 mutations. Enzyme replacement therapy (LAMZEDE^R) was approved for use in Europe in August 2018. Here, we describe seven individuals from four families, diagnosed at 3–23 years of age, and who were referred to a clinical geneticist for etiologic exploration of syndromic hearing loss, associated with moderate learning disabilities. Exome sequencing had been used to establish the molecular diagnosis in five cases, including a two‐sibling pair. In the remaining two patients, the diagnosis was obtained with screening of urinary oligosaccharides excretion and the association of deafness and hypotonia. These observations emphasize that the clinical diagnosis of AM can be challenging, and that it is likely an underdiagnosed rare cause of syndromic hearing loss. Exome sequencing can contribute significantly to the early diagnosis of these nonspecific mild phenotypes, with advantages for treatment and management.     

Sodium fusidate ameliorates the course of diabetes induced in mice by multiple low doses of streptozotocin

We studied the effects of the immunosuppressant sodium fusidate (fusidin) on murine immunoinflammatory diabetes mellitus (DM) induced by multiple low doses of streptozotocin (SZ). Fusidin was given by gavage to three strains of mice (C57KsJ, C57BL/6, CD1) at doses 10 or 100 mg/kg body weight every other day. The drug was administered as an early or late prophylactic regime starting either 1 day prior to the first or after the fifth and last injection of SZ. In both situations the largest dose of fusidin successfully reduced the clinical, chemical and histological signs of DM, the treated mice having significantly lower glycaemic values and milder (often absent) insulitis compared with sham-treated animals or controls given SZ alone. The antidiabetogenic effect was long-lasting as it was maintained up to 1 month after cessation of therapy. In contrast, fusidin prophylaxis failed to prevent development of hyperglycaemia acutely induced by one single and high (160 mg/kg) dose of SZ, which is a model of DM primarily due to the toxic action of SZ on the beta cells and does not involve immunopathogenetic mechanisms.On day 14 after SZ, fusidin markedly altered the circulating cytokine profile induced in vivo by ConA, reducing the levels of IFN-gamma, IL-2 and TNF-alpha and augmenting the level of IL-6. However, only the inhibitory effect of the drug on the synthesis/release of IFN-gamma seemed to be causally related to its capacity to counteract the SZ-induced DM. In fact, the disease was prevented by a neutralizing monoclonal antibody (mAb) against IFN-gamma, but not by anti-IL-2 receptor mAb, a soluble form of TNF-receptor type 1 or recombinant human IL-6. The prevention of disease by fusidin was also partly reversed by exogenously administered recombinant mouse IFN-gamma.The data provide further in-vivo evidence for the anti-diabetogenic and immunomodulatory properties of fusidin and indicate that this drug could have a role in prevention and treatment of human type 1 DM.     

c-Fos Expression in Ouabain-Treated Vascular Smooth Muscle Cells from rat Aorta: Evidence for an Intracellular-Sodium-Mediated, Calcium-Independent Mechanism

Contractile activity imposed by chronic electrical stimulation of a primary skeletal muscle cell culture grown on microcarriers over several days led to an increase of slow myosin heavy chain I (MHCI) and a decrease of fast MHCII expression at mRNA and protein levels, indicating an ongoing fast-to-slow transformation. Only patterns with periods of continuous stimulation of > 5 min in a 45 min cycle were capable of inducing a fibre type transformation, and this was independent of the applied stimulation frequency over the range 1-10 Hz. We have shown before that the calcineurin-NFATc1 signalling pathway is indispensable in mediating MHCI upregulation during fibre type transformation. Therefore, subcellular localization of NFATc1 was studied immunocytochemically. This revealed that only one stimulation train lasting for > 5 min was sufficient to induce nuclear import of this factor, which was about complete after 20 min of continuous stimulation. For both induction of NFATc1 import and MHCI mRNA upregulation, the minimum stimulation interval of > 5 min was sufficient and stimulation frequency was not crucial between 1 and 10 Hz. Repetition of stimulation cycles, with pauses (< 40 min) shorter than the time required for complete export of NFATc1, led to an accumulation of NFATc1 in the nuclei with each cycle and thus to an amplification of the transformation signal during extended periods of electrostimulation. The temporal behaviour of NFATc import/export appears to determine the effectiveness of various electrostimulation protocols in inducing fast-to-slow fibre transformation.     

Increased CD5-positive B lymphocytes in type I diabetes.

CD5+ B lymphocytes have been implicated in the production of polyspecific and monospecific antibodies that bind self-antigens, and increased proportions of this B cell subset occur in patients with some autoimmune diseases. We investigated the proportion of peripheral blood CD5+ B lymphocytes in type I diabetic patients. Compared with 18 age-matched healthy subjects, 11 out of 28 (39.2%) type I diabetic patients had increased proportions of circulating CD5. B lymphocytes with no alterations in the numbers of circulating B and T lymphocytes. Although all patients with increased CD5 B lymphocytes also had serum islet cell antibodies and/or insulin autoantibodies, the occurrence of increased proportions of CD5+ B lymphocytes and serum autoantibodies was not significantly correlated. Increased proportions of CD5+ B lymphocytes was not related to the time elapsed since the clinical onset of diabetes. In addition, regardless of being increased or normal, the proportion of CD5+ B lymphocytes appeared as a relatively constant phenotype after 1 year of follow-up studies at 3-month intervals in eight patients. Although the significance of these findings remains to be established, the possibility exists that CD5+ cells play a role in the pathogenesis of type I diabetes.