Fatigue and fitness modelled from the effects of training on performance

Summary The purpose of this study was to compare two ways of estimating both fatigue and fitness indicators from systems model of the effects of training on performance. The model was applied to data concerning the training of a hammer thrower. The variations in performance were mathematically related to the successive amounts of training. The model equation was composed of negative (NF) and positive (PF) functions. The NF and PF were associated with the fatigue and fitness estimated in previous studies. Using another method, fatigue and fitness indicators were estimated from a combination of NF and PF. The influence of training on performance was negatively associated with fatigue (NI), and positively to fitness (PI). The changes in performance were well described by the model in the present study (r = 0.96,N = 19,P<0.001). Significant correlations were observed between NF and NI (r = 0.93,P < 0.001) on the one hand and between PF and PI (r = 0.90,P < 0.001) on the other. The absolute values and the time variations of PI and NI were closer to the change in performance than NF and PF. The NF and PF were accounted for mainly by the accumulation of amounts of training. On the other hand, NI and PI were accounted for rather by the impact of these amounts of training on performance.     

Pathology of inverted Takotsubo cardiomyopathy

Myocardial dysfunction without coronary involvement may occur in acute cerebral diseases. The inverted Takotsubo pattern has been recently recognized as a novel heart neurologic stress-related syndrome. We report on the case of a 40-year-old woman presenting with massive subarachnoid hemorrhage and brain death. Echocardiography revealed an extensive left ventricular circumferential akinesis except at the apex. Histologic analysis of the heart confirmed the absence of myocardial infarction and revealed only sparse foci of myocyte necrosis with contraction bands in the akinetic areas.     

Visualizing cytokine-secreting cells in situ in the rhesus macaque model of chronic gut inflammation

Cytokine-producing cells in gut-associated lymphoid tissues of rhesus macaques with chronic enterocolitis were studied. The confocal microscopy technique that we developed enables simultaneous in situ visualization of multiple extra- and/or intracellular antigens at a resolution higher than that allowed by light or epifluorescence microscopy. The presence of interleukin-6 (IL-6)-, tumor necrosis factor alpha (TNF-alpha)-, and IL-1-alpha-producing cells was focally intense in the colon lamina propria of the affected animals. The IL-1-alpha-producing cells were T lymphocytes (CD3+), while the TNF-alpha-producing cells were both macrophages (CD68+/HAM56+/LN5+) and T lymphocytes (CD3+). The IL-6-producing cells within the colon consisted of T lymphocytes and macrophages. The amount of IL-6-producing cells seen in macaques with enterocolitis was significantly higher (P<0.001) than that seen in the healthy control animal, while TNF-alpha- and IL-1-alpha-producing cells were seen only in macaques with enterocolitis. Most of the T lymphocytes that produced cytokines were detected in the lamina propria, while the macrophages were most prominent in highly inflamed regions of the lamina propria. Taken together, our findings indicate that there might be immunological similarity between chronic enterocolitis of rhesus macaques and humans, suggesting the potential use of the nonhuman primate model for the validation of novel therapies.     

Biochemical analyses of multiple fractions of PKR purified from Escherichia coli.

PKR is a cellular protein kinase activated by double-stranded RNA (dsRNA) that phosphorylates eukaryotic initiation factor alpha (eIF2alpha) and inhibits protein translation. Activation of PKR is accompanied by Ser/Thr autophosphorylation on multiple sites. Because PKR negatively regulates cell growth, overexpression and purification of PKR are difficult to achieve. Here, we describe overexpression and purification of recombinant PKR protein from Escherichia coli under native conditions at the milligram level. Affinity, ion exchange, and gel filtration chromatographies revealed multiple fractions of PKR with distinctive biochemical characteristics. During gel filtration, a small amount of PKR was found in a high molecular weight (>300 kDa) fraction that also contained endogenous bacterial RNA. The PKR in this fraction has a constitutive substrate phosphorylation activity. The majority of PKR is found in fractions of lower molecular weight and is free of RNA but is differentially phosphorylated as examined by isoelectric focusing electrophoresis and can be further separated by gradient anion exchange chromatography. PKR eluted with low salt has a lower level of basal autophosphorylation, and its kinase activity can be induced by dsRNA. With an increasing NaCl gradient, the purified PKR exhibits an increased level of autophosphorylation and constitutive kinase activity but reduced dsRNA inducibility. The highest salt eluent of PKR exhibits little dsRNA-induced activation. The inducible activation of high salt eluent PKR by dsRNA can be partially restored by treatment with protein phosphatase 1. The production of multiple fractions of PKR with different biochemical properties in E. coli suggests that the spectrum of PKR activity and regulation in mammalian cells is likely to be similarly complex.     

Mutation analysis of the SDHD gene in four kindreds with familial paraganglioma: description of one novel germline mutation.

The familial paraganglioma syndrome is an autosomal dominant disorder characterized by the presence of carotid body paragangliomas and, less frequently, paragangliomas of the glomus jugulare, glomus vagale, and adrenal pheochromocytomas. Germline mutations of the genes for succinate dehydrogenase subunits D, B, or C (SDHD, SDHB, SDHC) have been identified in some kindreds with familial paraganglioma. In this study, we report the clinicopathologic features of four different kindreds with familial paraganglioma, which were screened for germline mutations in the SDHD gene. DNA was obtained from tumor and normal tissue, as well as from peripheral blood. Mutation analysis was performed by single-strand conformation polymorphism analysis and DNA sequencing. SDHD germline mutations were detected in the affected family members of the four families, as well as in several asymptomatic carriers. An identical mutation in exon 4 of SDHD (334-337delACTG) was identified in two apparently unrelated kindreds. The third family showed a germline mutation in exon 2 (W43X). The mutations present in these three families had been previously described in Spanish families, suggesting a founder effect. The fourth family exhibited a mutation in exon 2 of SDHD (170-171delTT), which had not been previously identified. The affected family members of the four kindreds showed paragangliomas, located in the head and neck region, and all of them were benign. These results confirm that genetic testing of SDHD may be a powerful tool for the identification of the syndrome in patients with multiple or bilateral paragangliomas.     

Anatomical evidence for direct connections between the shell and core subregions of the rat nucleus accumbens

The nucleus accumbens is thought to subserve different aspects of adaptive and emotional behaviors. The anatomical substrates for such actions are multiple, parallel ventral striatopallidal output circuits originating in the nucleus accumbens shell and core subregions. Several indirect ways of interaction between the two subregions and their associated circuitry have been proposed, in particular through striato-pallido-thalamic and dopaminergic pathways. In this study, using anterograde neuroanatomical tracing with Phaseolus vulgaris-leucoagglutinin and biotinylated dextran amine as well as single-cell juxtacellular filling with neurobiotin, we investigated the intra-accumbens distribution of local axon collaterals for the identification of possible direct connections between the shell and core subregions. Our results show widespread intra-accumbens projection patterns, including reciprocal projections between specific parts of the shell and core. However, fibers originating in the core reach more distant areas of the shell, including the rostral pole (i.e. the calbindin-poor part of the shell anterior to the core) and striatal parts of the olfactory tubercle, than those arising in the shell and projecting to the core. The latter projections are more restricted to the border region between the shell and core. The density of the fiber labeling within both the shell and core was very similar. Moreover, specific intrinsic projections within shell and core were identified, including a relatively strong projection from the rostral pole to the rostral shell, reciprocal projections between the rostral and caudal shell, as well as projections within the core that have a caudal-to-rostral predominance. The results of the juxtacellular filling experiments show that medium-sized spiny projection neurons and medium-sized aspiny neurons (most likely fast-spiking) contribute to these intra-accumbens projections. While such neurons are GABAergic, the intrastriatal projection patterns indicate the existence of lateral inhibitory interactions within, as well as between, shell and core subregions of the nucleus accumbens.     

Autoantibodies directed against the amino-terminal domain I of human calpastatin (ACAST-DI Ab) in connective tissue diseases. High levels of ACAST-DI Ab are associated with vasculitis in lupus

To identify new autoantibody populations in patients with rheumatic diseases, a cDNA expression library was immunoscreened with a rheumatoid arthritis (RA) patient's serum which contains autoantibodies binding to uncharacterized polypeptides by Western-blotting. One clone encoding the amino-terminal region (Nt) [domain L and half of domain I] of human calpastatin was selected. Different fragments of the selected cDNA were prepared and the corresponding recombinant polypeptides were produced by in vitro translation and analysed by Western blotting. Most RA sera bound to recombinant amino-terminal region and domain I but not to domain L. This prompted us to use a recombinant polypeptide corresponding to the domain I of calpastatin as the antigen in a solid-phase ELISA to test sera from patients with various systemic rheumatic diseases and healthy controls.Anti-calpastatin domain I antibodies (ACAST-DI Ab), were detected by ELISA in RA, systemic lupus erythematosus (SLE), Sj?gren's syndrome and control sera at respective frequencies of 10, 9, 0 and 1%. These Ab did not have prognostic value in early RA; high levels were significantly associated with vasculitis in SLE. Antibodies reacting with the calpastatin amino-terminal region are produced during systemic rheumatic diseases and are predominantly directed against domain I. High levels of these Ab may constitute a marker of vasculitis in SLE.     

Recombinant VP9-based enzyme-linked immunosorbent assay for detection of immunoglobulin G antibodies to Banna virus (genus Seadornavirus)

Banna virus (BAV, genus Seadornavirus, family Reoviridae) is an arbovirus suspected to be responsible for encephalitis in humans. Two genotypes of this virus are distinguishable: A (Chinese isolate, BAV-Ch) and B (Indonesian isolate, BAV-In6969) which exhibit only 41% amino-acid identity in the sequence of their VP9.The VP7 to VP12 of BAV-Ch and VP9 of BAV-In6969 were expressed in bacteria using pGEX-4T-2 vector. VP9 was chosen to establish an ELISA for BAV, based mainly on two observations: (i). VP9 is a major protein in virus-infected cells and is a capsid protein (ii). among all the proteins expressed, VP9 was obtained in high amount and showed the highest immuno-reactivity to anti-BAV ascitic fluid.The VP9s ELISA was evaluated in three populations: French blood donors and two populations (blood donors and patients with a neurological syndrome) from Malaysia, representing the region where the virus was isolated in the past.The specificity of this ELISA was >98%. In mice injected with live BAV, the assay detected IgG-antibody to BAV infection 21 days post-injection, which was confirmed by Western blot using BAV-infected cells.The VP9 ELISA permits to determine the sero-status of a population without special safety precautions and without any requirements to propagate the BAV. This test should be a useful tool for epidemiological survey of BAV.     

Behavioral Profiles of Genetically Selected Aggressive and Nonaggressive Male Wild House Mice in Two Anxiety Tests

Artificially selected aggressive (SAL) and non-aggressive (LAL) male house mice were tested in a hexagonal tunnel maze and light-dark preference (LD) box to determine if the bidirectional selection for aggressive behavior leads to a coselection for different levels of trait anxiety. The tunnel maze consists of an open, brightly lit central arena surrounded by a complex system of interconnecting tunnels. As in the LD box, animals which spend less time and are less active in the brightly illuminated section of the maze are considered to have higher anxiety levels. In the tunnel maze, the LAL mice showed more exploration and spent more time in the central arena than the SAL animals, but only during the final 2 min of the 6-min test. This reduced preference for the central arena was not due to general inactivity or a failure of the SAL to find the central arena and indicates a higher level of state anxiety in the aggressive animals. In contrast, no anxiety-like differences were found in the LD box, either for the percentage of time spent in the light compartment or for the number of crossings. SAL males actually showed higher levels of moving and rearing, and lower levels of freezing, than did LAL males.