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1.
<Emphasis Type="Italic">V</Emphasis>O<Subscript>2</Subscript>max during successive maximal efforts 总被引:1,自引:0,他引:1
Foster C Kuffel E Bradley N Battista RA Wright G Porcari JP Lucia A deKoning JJ 《European journal of applied physiology》2007,102(1):67-72
The concept of VO2max has been a defining paradigm in exercise physiology for >75 years. Within the last decade, this concept has been both
challenged and defended. The purpose of this study was to test the concept of VO2max by comparing VO2 during a second exercise bout following a preliminary maximal effort exercise bout. The study had two parts. In Study #1,
physically active non-athletes performed incremental cycle exercise. After 1-min recovery, a second bout was performed at
a higher power output. In Study #2, competitive runners performed incremental treadmill exercise and, after 3-min recovery,
a second bout at a higher speed. In Study #1 the highest VO2 (bout 1 vs. bout 2) was not significantly different (3.95 ± 0.75 vs. 4.06 ± 0.75 l min−1). Maximal heart rate was not different (179 ± 14 vs. 180 ± 13 bpm) although maximal V
E was higher in the second bout (141 ± 36 vs. 151 ± 34 l min−1). In Study #2 the highest VO2 (bout 1 vs. bout 2) was not significantly different (4.09 ± 0.97 vs. 4.03 ± 1.16 l min−1), nor was maximal heart rate (184 + 6 vs. 181 ± 10 bpm) or maximal V
E (126 ± 29 vs. 126 ± 34 l min−1). The results support the concept that the highest VO2 during a maximal incremental exercise bout is unlikely to change during a subsequent exercise bout, despite higher muscular
power output. As such, the results support the “classical” view of VO2max. 相似文献
2.
Annette Eastwood Pitre C. Bourdon Robert T. Withers Christopher J. Gore 《European journal of applied physiology》2009,105(5):715-721
This study assessed the relationship between haemoglobin mass (Hbmass) and maximum oxygen consumption (VO2max) in adolescents over 1 year. Twenty-three subjects (11–15 years) participated; 12 undertook ~12 months of cycle training
(cyclists) and 11 were sedentary (controls). Hbmass and VO2max were measured approximately every 3 months. At baseline there was a high correlation (r = 0.82, P < 0.0001) between relative VO2max (ml kg−1 min−1) and relative Hbmass (g kg−1). During 12 months there was a significant increase in relative VO2max of the cyclists but not the controls; however, there was no corresponding increase in relative Hbmass of either group. The correlation between percent changes in relative VO2max and relative Hbmass was not significant for cyclists (r = 0.31, P = 0.33) or controls (r = 0.42, P = 0.19). Training does not increase relative Hbmass in adolescents consistent with a strong hereditary role for Hbmass and VO2max. Hbmass may be used to identify adolescents who have a high VO2max. 相似文献
3.
Cao ZB Miyatake N Higuchi M Ishikawa-Takata K Miyachi M Tabata I 《European journal of applied physiology》2009,105(2):289-296
The purpose of the study was to develop a new non-exercise VO2max prediction model using a physical activity (PA) variable determined by pedometer-determined step counts (SC, steps day−1) in Japanese women aged 20–69 years old. Eighty-seven and 102 subjects were used to develop the prediction model, and to
validate the new model, respectively. VO2max was measured using a maximal incremental test on a bicycle ergometer. SC was significantly related to VO2max (partial correlation coefficient r = 0.40, P < 0.001) after adjusting for BMI (kg m−2) and age (years). When the new prediction equation developed by multiple regression to estimate VO2max from age, BMI, and SC (R = 0.71, SEE = 5.3 ml kg−1 min−1, P < 0.001) was applied to the Validation group, predicted VO2max correlated well with measured VO2max (r = 0.81, P < 0.001), suggesting that SC is a useful PA variable for non-exercise prediction of VO2max in Japanese women. 相似文献
4.
Weida?Pan Yeqi?Fu Auwalu?Yusuf?Abdullahi Mingwei?Wang Xianli?Shi Fang?Yang Xingang?Yu Xinxin?Yan Pan?Zhang Jianxiong?Hang Guoqing?Li
To develop T m -shift genotyping method for detection of cat-derived Giardia lamblia, two sets of primers with two GC-rich tails of unequal length attached to their 5′-end were designed according to two SNPs (BG434 and BG170) of β-giardin (bg) gene, and specific PCR products were identified by inspection of a melting curve on real-time PCR thermocycler. A series of experiments on the stability, sensitivity, and accuracy of T m -shift method was tested, and clinical samples were also detected. The results showed that two sets of primers based on SNP could distinguish accurately between assemblages A and F. Coefficient of variation of T m values of assemblage A and F was 0.14 and 0.07% in BG434 and 0.10 and 0.11% in BG170, respectively. The lowest detection concentration was 4.52 × 10?5 and 4.88 × 10?5 ng/μL samples of assemblage A and F standard plasmids. The T m -shift genotyping results of ten DNA samples from the cat-derived G. lamblia were consistent with their known genotypes. The detection rate of clinical samples by T m -shift was higher than that by microscopy, and their genotyping results were in complete accordance with sequencing results. It is concluded that the T m -shift genotyping method is rapid, specific, and sensitive and may provide a new technological mean for molecular detection and epidemiological investigation of the cat-derived G. lamblia. 相似文献
5.
To provide physicians with an objective and quantitative measurement of single-sided facial paralysis, the paper presents
a computer-based approach that is different from the nine existing, subjective and hand-performed international scales, such
as House-Brackman. For voluntary expressions of a patient, this approach used Pface, which stems from Dface, to measure the asymmetry between two sides of the face and used eigenflow to measure the expression variations between the
patient and normal subjects. The results from Pface and eigenflow were then combined by the support vector machine produce to Pdegree. A study of 25 subjects revealed that Pdegree could differentiate paralysis states (Pdegree≧0) and normal states (Pdegree<0), with the ability to grade facial paralysis automatically. Moreover, the Pface of specific facial areas can be used in the supervision of the rehabilitation process. 相似文献
6.
Galba truncatula snails were experimentally infected with either of two different isolates of Fasciola gigantica, originating from Egypt or China, to determine the influence of these isolates on the characteristics of snail infections. The survival rates of G. truncatula on day 30 post-exposure were 90.0% and 60.2% in the Egyptian and Chinese groups, respectively. The frequency of cercaria-shedding snails within the Egyptian group was 79.8%, whereas in the Chinese group it was 22.4%. The parasite origin had a significant effect on the durations of the prepatent and patent periods. The mean number of cercariae shed from the Egyptian group was significantly greater than that shed from the Chinese group (a mean of 275.5 per cercaria-shedding snail compared with 29.0). These results could be explained by the fact that G. truncatula might be a natural intermediate host for F. gigantica in Egypt, and the greater adaptability of the Egyptian miracidia of F. gigantica to unusual snail hosts. These results demonstrate the influence of the geographic origin of the parasite on the success of trematodes infecting snails. 相似文献
7.
Karina?M.?Rebello Luzia?M.?C.?C?rtes Bernardo?A.?S.?Pereira Bernardo?M.?O.?Pascarelli Suzana?C?rte-Real Léa?C.?Finkelstein Rosa?T.?Pinho Claudia?M.?d’Avila-Levy Carlos?R.?Alves 《Parasitology research》2009,106(1):95-104
Leishmania (Viannia) braziliensis is the major causative agent of American tegumentary leishmaniasis, a disease that has a wide geographical distribution and
is a severe public health problem. The cysteine proteinase B (CPB) from Leishmania spp. represents an important virulence factor. In this study, we characterized and localized cysteine proteinases in L. (V.) braziliensis promastigotes. By a combination of triton X-114 extraction, concanavalin A-affinity, and ion exchange chromatographies, we
obtained an enriched fraction of hydrophobic proteins rich in mannose residues. This fraction contained two proteinases of
63 and 43 kDa, which were recognized by a CPB antiserum, and were partially sensitive to E-64 in enzymatic assays with the
peptide Glu-Phe-Leu. In confocal microscopy, the CPB homologues localized in the peripheral region of the parasite. This data
together with direct agglutination and flow cytometry assays suggest a surface localization of the CPB homologues. The incubation
of intact promastigotes with phospholipase C reduced the number of CPB-positive cells, while anti-cross-reacting determinant
and anti-CPB antisera recognized two polypeptides (63 and 43 kDa) derived from phospholipase C treatment, suggesting that
some CPB isoforms may be glycosylphosphatidylinositol-anchored. Collectively, our results suggest the presence of CPB homologues
in L. braziliensis surface and highlight the need for further studies on L. braziliensis cysteine proteinases, which require enrichment methods for enzymatic detection. 相似文献
8.
Carrasco L Sañudo B de Hoyo M Pradas F Da Silva ME 《European journal of applied physiology》2011,111(9):2271-2279
The aim of the study was to determine the effectiveness of low-frequency vibration recovery (LFV-rec) on blood lactate removal,
muscle contractile properties, and on time to exhaustion during cycling at maximal oxygen uptake power output (pVO2max). Twelve active males carried out three experimental sessions. In session 1, participant’s maximal oxygen uptake (VO2max) and pVO2max were determined, and in sessions 2 and 3, the participants performed a fatiguing exercise (2 min of cycling at pVO2max) and then a 15 min recovery period using one of two different methods: LFV-rec which consisted on sitting with feet on the
vibratory platform (20 Hz; 4 mm) and passive recovery (P-rec), sitting without vibration stimulus. After that, participants
performed an all-out exercise test on cycle ergometer at pVO2max. In the recovery period, variables such as heart rate (HR), blood lactate concentration [Lac], and tensiomyographic parameters
(D
m: maximal radial displacement; T
s: time of contraction maintenance, and T
r: relaxation time) were measured. In an all-out exercise test, mean time to exhaustion (TTE), total distance covered (TD),
mean cycling velocity (V
m), and maximal HR (HRmax) were also assessed. The results showed no effect of recovery strategy on any of the assessed variables; nevertheless, higher
values, although not significant, were observed in TTE, TD, and V
m after LFV-rec intervention. In conclusion, LFV-rec strategy applied during 15 min after short and intense exercise does not
seem to be effective on blood lactate removal, muscle contractile properties, and on time to exhaustion during cycling at
pVO2max. 相似文献
9.
10.
Fidelis Cho-Ngwa Melanie Abongwa Moses N Ngemenya Kennedy D Nyongbela 《BMC complementary and alternative medicine》2010,10(1):62
Background
The current treatment of onchocerciasis relies on the use of ivermectin which is only microfilaricidal and for which resistant parasite strains of veterinary importance are increasingly being detected. In the search for novel filaricides and alternative medicines, we investigated the selective activity of crude extracts of Margaritaria discoidea and Homalium africanum on Onchocerca ochengi, a model parasite for O. volvulus. These plants are used to treat the disease in North West Cameroon. 相似文献11.
Bardia A Tiwari SK Gunisetty S Anjum F Nallari P Habeeb MA Khan AA 《Inflammation research》2012,61(4):359-365
Objective
The present study was designed to investigate the role of X-ray cross-complementing group 1 (XRCC1) and apurinic/apyrimidinic endonuclease 1 (APE1) polymorphisms in apoptosis and the risk of ulcerative colitis (UC). 相似文献12.
13.
María del Rosario Robles James E. Loudon John M. Kinsella Mandala Hunter-Ishikawa David S. Miller Michelle L. Sauther Frank P. Cuozzo 《Acta parasitologica / Witold Stefański Institute of Parasitology, Warszawa, Poland》2010,55(3):270-275
Lemuricola (Madoxyuris) bauchoti Chabaud, Brygoo et Petter, 1965 is redescribed from material collected from the ring-tailed lemur, Lemur catta, from the Beza Mahafaly Special Reserve in Madagascar using the scanning electron microscope. This is a new host record and
the first oxyurid reported from the ring-tailed lemur. Previously, records of each species of the subgenus Madoxyuris have been restricted to a single host species, but the close relationship between these nematodes and their Strepsirrhini
hosts will only be proven when additional records fill in the gaps in their distribution. 相似文献
14.
15.
Pseudomonas aeruginosa is an opportunistic pathogen of immunocompromised hosts. In cystic fibrosis (CF), P. aeruginosa causes acute and chronic lung infections that result in significant morbidity and mortality. P. aeruginosa possesses several traits that contribute to its ability to colonize and persist in acute and chronic infections. These include
high resistance to antimicrobials, ability to form biofilms, plethora of virulence products, and metabolic versatility. In
P. aeruginosa, a cell-to-cell communication process termed quorum sensing (QS) regulates many of these factors that contribute to its pathogenesis.
Recent evidence suggests that the CF lung environment presents a specialized niche for P. aeruginosa. The relationship of P. aeruginosa QS, biofilm formation, and the CF lung environment is discussed. 相似文献
16.
Emily Staples Beatriz Morillo-Gutierrez Jessica Davies Daniel Petersheim Michel Massaad Mary Slatter Dimitra Dimou Rainer Doffinger Scott Hackett Dinkantha Kumararatne James Hadfield Matthew D. Eldridge Raif S. Geha Mario Abinun James E. D. Thaventhiran 《Journal of clinical immunology》2017,37(5):415-418
17.
Pierre Berthet-Rayne Gauthier Gras Konrad Leibrandt Piyamate Wisanuvej Andreas Schmitz Carlo A. Seneci Guang-Zhong Yang 《Annals of biomedical engineering》2018,46(10):1663-1675
Endoscopic procedures have transformed minimally invasive surgery as they allow the examination and intervention on a patient’s anatomy through natural orifices, without the need for external incisions. However, the complexity of anatomical pathways and the limited dexterity of existing instruments, limit such procedures mainly to diagnosis and biopsies. This paper proposes a new robotic platform: the Intuitive imaging sensing navigated and kinematically enhanced (\(i^{2}Snake\)) robot that aims to improve the field of endoscopic surgery. The proposed robotic platform includes a snake-like robotic endoscope equipped with a camera, a light-source and two robotic instruments, supported with a robotic arm for global positioning and for insertion of the \(i^{2}Snake,\) and a master interface for master–slave teleoperation. The proposed robotic platform design focuses on ergonomics and intuitive control. The control workflow was first validated in simulation and then implemented on the robotic platform. The results are consistent with the simulation and show the clear clinical potential of the system. Limitations such as tendon backlash and elongation over time will be further investigated by means of combined hardware and software solutions. In conclusion, the proposed system contributes to the field of endoscopic surgical robots and could allow to perform more complex endoscopic surgical procedures while reducing patient trauma and recovery time. 相似文献
18.
Danshen, the dried root of Salvia miltiorrhiza, is a Chinese medicine used to promote blood flow and treat vascular disease. The present article reviews the pharmacological
effects of Danshen on cerebral infarction and possible interactions between Danshen and Western drugs. Danshen may reduce or prolong the development of atherosclerosis and may have anti-hypertensive and anti-platelet aggregation effects,
which prevent cerebral infarction. Danshen may enhance endogenous anti-oxidative enzyme activities such as the expression of endothelial nitric oxide synthase and may
scavenge oxygen free radicals. Prevention and treatment of cerebral infarction by Danshen involves multiple pathways, including anti-atherosclerosis, anti-hypertension, anti-platelet aggregation, anti-inflammatory
and anti-oxidative effects. 相似文献
19.
Biological pacemakers based on <Emphasis Type="Italic">I</Emphasis><Subscript>f</Subscript> 总被引:1,自引:0,他引:1
Rosen MR Brink PR Cohen IS Robinson RB 《Medical & biological engineering & computing》2007,45(2):157-166
Biological pacemaking as a replacement for or adjunct to electronic pacemakers has been a subject of interest since the 1990s.
In the following pages, we discuss the rational for and progress made using a hyperpolarization activated, cyclic nucleotide
gated channel isoform to carry the I
f pacemaker current in gene and cell therapy approaches. Both strategies have resulted in effective biological pacemaker function
over a period of weeks in intact animals. Moreover, the use of adult human mesenchymal stem cells as a platform for carrying
pacemaker genes has resulted in the formation of functional gap junctions with cardiac myocytes in situ leading to effective
and persistent propagation of pacemaker current. The approaches described are encouraging, suggesting that biological pacemakers
based on this strategy can be brought to clinical testing. 相似文献
20.
Passero LF Carvalho AK Bordon ML Bonfim-Melo A Toyama MH Corbett CE Laurenti MD 《Inflammation research》2012,61(3):255-263