Hemoconcentration induced by exercise: Revisiting the Dill and Costill equation.

The Dill and Costill equation is used to estimate the exercise-induced hemoconcentration. However, this calculation requires drawing an extra whole-blood sample, which cannot be frozen and has to be analyzed with dedicate instrumentation in a relative short time. The aim of the present study was to explore the usefulness of some serum biochemical parameters to estimate hemoconcentration induced by exhaustive exercise. Fourteen healthy male subjects (19-34 years) performed a15-min running test at 110% of anaerobic threshold speed. Hemoglobin, hematocrit, brain natriuretic peptide (BNP), creatinine, gamma-glutamyltransferase (GGT), total-proteins, albumin, total calcium (Ca), K(+), Na(+), and Cl(-) were determined in blood samples taken before, after exercise, and after a 30-min recovery period. Plasma volume loss (ΔPV) was calculated by Dill and Costill equation. At post-exercise and after recovery, the percentage increments of total-proteins, albumin, GGT and Ca correlated significantly with ΔPV. Bland-Altman analyses showed that correcting BNP, creatinine, and K(+) concentration by Ca percentage increments yield biases and limits of agreement that are acceptable when compared with Dill and Costill equation correction. Ca concentration may be used as a hemoconcentration biomarker in high-intensity exercise, which would allow scientists and physicians avoid extra costs, facilitate in-field research, and delayed estimation of hemoconcentration using stored serum samples.

Exercise effects on erythrocyte deformability in exercise-induced arterial hypoxemia.

Exercise-induced arterial hypoxemia (EIAH) is often found in endurance-trained subjects at high exercise intensity. The role of erythrocyte deformability (ED) in EIAH has been scarcely explored. We aimed to explore the role of erythrocyte properties and lactate accumulation in the response of ED in EIAH. ED was determined in 10 sedentary and in 16 trained subjects, both before and after a maximal incremental test, and after recovery, along with mean corpuscular volume (MCV) and red blood cell lactate concentrations. EIAH was found in 6 trained subjects (∆SaO2=-8.25±4.03%). Sedentary and non-EIAH trained subjects showed reduced ED after exercise, while no effect on ED was found in EIAH trained subjects. After exercise, lactate concentrations rose and MCV increased equally in all groups. ED is strongly driven by cell volume, but the different ED response to exercise in EIAH shows that other cellular mechanisms may be implicated. Interactions between membrane and cytoskeleton, which have been found to be O2-regulated, play a role in ED. The drop in SaO2 in EIAH subjects can improve ED response to exercise. This can be an adaptive mechanism that enhances muscular and pulmonary perfusion, and allows the achievement of high exercise intensity in EIAH despite lower O2 arterial transport.

The LRRK2 inhibitor GSK2578215A induces protective autophagy in SH-SY5Y cells: involvement of Drp-1-mediated mitochondrial fission and mitochondrial-derived ROS signaling.

Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene have been associated with Parkinson's disease, and its inhibition opens potential new therapeutic options. Among the drug inhibitors of both wild-type and mutant LRRK2 forms is the 2-arylmethyloxy-5-subtitutent-N-arylbenzamide GSK257815A. Using the well-established dopaminergic cell culture model SH-SY5Y, we have investigated the effects of GSK2578215A on crucial neurodegenerative features such as mitochondrial dynamics and autophagy. GSK2578215A induces mitochondrial fragmentation of an early step preceding autophagy. This increase in autophagosome results from inhibition of fusion rather than increases in synthesis. The observed effects were shared with LRRK2-IN-1, a well-described, structurally distinct kinase inhibitor compound or when knocking down LRRK2 expression using siRNA. Studies using the drug mitochondrial division inhibitor 1 indicated that translocation of the dynamin-related protein-1 has a relevant role in this process. In addition, autophagic inhibitors revealed the participation of autophagy as a cytoprotective response by removing damaged mitochondria. GSK2578215A induced oxidative stress as evidenced by the accumulation of 4-hydroxy-2-nonenal in SH-SY5Y cells. The mitochondrial-targeted reactive oxygen species scavenger MitoQ positioned these species as second messengers between mitochondrial morphologic alterations and autophagy. Altogether, our results demonstrated the relevance of LRRK2 in mitochondrial-activated pathways mediating in autophagy and cell fate, crucial features in neurodegenerative diseases.

[Expression of beta-amyloid and tau-protein in mastocytes in Alzheimer disease]. / Ekspressiia beta-amiloida i tau-proteina v tuchnykh kletkakh pri bolezni Al'tsgeimera.

With immunochemical assay, the expression of B-amyloid and tau-protein in the mast cells of the stomach and skin was first detected in patients with Alzheimer's disease (AD), which supports the hypothesis that AD is a systemic disease involving different organs and tissues. Verification of expression of two key peptides that participate in the pathogenesis of AD in the samples of extra-brain tissues allows B-amyloid and tau-protein to be regarded as promising markers and mast cells to be considered to the most suitable object for lifetime diagnosis of neurodegenerative diseases.

Gut neuroendocrine cells: relationship to the proliferative activity and apoptosis of mucous epitheliocytes in aging.

OBJECTIVES: Diffuse neuroendocrine system (DNES) cells regulate homeostasis via neurocrine, endocrine and paracrine mechanisms. Extensive effects of peptide hormones and biogenic amines necessitate studying of DNES cell biology in aging. In this connection, the functional morphology of gut neuroendocrine cells (NEC), proliferative activity and apoptosis of mucous epithelial cells in aging have been studied. MATERIAL AND METHODS: The study was performed on BALB/c-nu mice of 4, 21 and 34 months of age. NEC, proliferative activity and apoptosis of mucous epitheliocytes in stomach and duodenum have been studied by histochemical, immunohistochemical and morphometrical methods. RESULTS: The total number of NEC shows an increasing trend with advancing age. However, the different types of NEC elicit differential patterns. The total number of epithelial cell nuclei does not show any statistically significant difference during aging. The proliferative activity of mucous epitheliocytes also shows no difference among the three animal groups studied. On the contrary, the apoptotic index increases with advancing age. CONCLUSIONS: The results demonstrate that various gut NEC show differential behavior with age and their time-courses are dependent on the site of location (stomach or duodenum). The picture seems quite complex to allow a comprehensive interpretation, nonetheless it gives us some useful indications for further investigation. In fact, since the gut does not show evident gross age-related physiological changes, modifications with age in specific biological parameters can suggest the key mechanisms of compensative regulatory processes possibly acting during aging.

Adaptation of conformation-sensitive gel electrophoresis to an ALFexpress DNA sequencer to screen BRCA1 mutations.

Conformation-sensitive gel electrophoresis (CSGE) has been introduced as the most reliable method for the screening of large and multi-exon genes because of its simplicity, sensitivity and specificity. Based on heteroduplex formation and with the use of mildly denaturing solvents, it allows detection of single-base mutations with accuracy. This is important in genes such as BRCA1 and BRCA2, in which alterations span the entire gene. We have adapted the CSGE assay to a fluorescent platform--a DNA sequencer one-color technology--that reduces the time involved and enhances resolving power for the complete scanning of the BRCA genes. Electrophoresis has high sensitivity and is performed in less than three hours, and the gel does not require staining with ethidium bromide. Eighteen single-base and six frameshift mutations in the BRCA1 gene were analyzed. We compared the manual and fluorescent CSGE methods, and all mutations were detected with accuracy.

Frequency of germ-line BRCA1 mutations among Spanish families from a Mediterranean area.

We have carried out a study of breast cancer in Spanish families in which the entire coding region of the BRCA1 gene have been analyzed. To identify BRCA1 mutations, PTT and CSGE methods were used followed by direct sequencing. We investigated 51 breast cancer women with a family history. Among these we have identified 7 frameshifts mutations (15%), 185delAG (4 times), 1623del5 and 3450del4 (2 times), and 3 missense mutations, Ser1613Gly, Met1652Ile and Ala1708Glu, which are likely polymorphisms. These findings show that BRCA1 is implicated in a fraction of Spanish familial breast cancer similar to other countries. There was association between bilateral breast cancer and BRCA1 mutations. The CSGE technique has been demonstrated to be a highly reliable method for mutation screening because of its sensitivity and high throughput.

EWS/FLI-1 rearrangement in small round cell sarcomas of bone and soft tissue detected by reverse transcriptase polymerase chain reaction amplification.

Recent cloning of the t(11;22) region has led to the detection of a number of sequences involved in the breakpoints by substituting a sequence which encodes a putative RNA binding domain for that of the DNA binding domain of the human homologue of murine FLI-1. Several tumours display consistent translocation at t(11;22) (q24;q12), a finding that suggests these fusion transcripts could be expressed and detected by reverse transcriptase polymerase chain reaction amplification. To date, only a small number of Ewing's sarcomas (Es) and peripheral neuroectodermal tumours (pPNET) of bone have been tested with this novel molecular biology approach. In this study, we confirmed the presence of the three putative chimaeric transcripts on 7 cases of Es and pPNET sarcomas of bone and soft tissue, providing 100% positivity for the tested tumours. For comparative purposes, a number of other neuroectodermal tumours were analysed with negative results: esthesioneuroblastoma, retinoblastoma, Schwannoma. A primitive soft tissue sarcoma (ectomesenchymoma) with a 22 chromosome rearrangement did not express any transcript, nor did a number of non-neuroectodermal small round cell sarcomas of soft tissue (rhabdomyosarcomas) and bone (microcellular osteosarcoma), conventional bone sarcomas, leiomyosarcomas, malignant fibrous histiocytomas and synovial sarcomas. These results reinforce the value of molecular biology techniques for the correct assessment of histology difficult evaluable neoplasms, such as the group of small round cell tumours within the Es family.