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21.

Background

We have previously documented significant differences in orthogonal P wave morphology between patients with and without paroxysmal atrial fibrillation (PAF). However, there exists little data concerning normal P wave morphology. This study was aimed at exploring orthogonal P wave morphology and its variations in healthy subjects.

Methods

120 healthy volunteers were included, evenly distributed in decades from 20–80 years of age; 60 men (age 50+/-17) and 60 women (50+/-16). Six-minute long 12-lead ECG registrations were acquired and transformed into orthogonal leads. Using a previously described P wave triggered P wave signal averaging method we were able to compare similarities and differences in P wave morphologies.

Results

Orthogonal P wave morphology in healthy individuals was predominately positive in Leads X and Y. In Lead Z, one third had negative morphology and two-thirds a biphasic one with a transition from negative to positive. The latter P wave morphology type was significantly more common after the age of 50 (P < 0.01). P wave duration (PWD) increased with age being slightly longer in subjects older than 50 (121+/-13 ms vs. 128+/-12 ms, P < 0.005). Minimal intraindividual variation of P wave morphology was observed.

Conclusion

Changes of signal averaged orthogonal P wave morphology (biphasic signal in Lead Z), earlier reported in PAF patients, are common in healthy subjects and appear predominantly after the age of 50. Subtle age-related prolongation of PWD is unlikely to be sufficient as a sole explanation of this finding that is thought to represent interatrial conduction disturbances. To serve as future reference, P wave morphology parameters of the healthy subjects are provided.  相似文献   
22.
Expanded populations of CD4+ T cells lacking the co-stimulatory molecule CD28 (CD4+CD28null T cells) have been reported in several inflammatory disorders. In rheumatoid arthritis, increased frequencies of CD4+CD28null T cells in peripheral blood have previously been associated with extra-articular manifestations and human cytomegalovirus (HCMV) infection, but their presence in and contribution to joint manifestations is not clear. In the present article we investigated the distribution of CD4+CD28null T cells in the synovial membrane, synovial fluid and peripheral blood of RA patients, and analysed the association with erosive disease and anti-citrullinated protein antibodies. CD4+CD28null T cells were infrequent in the synovial membrane and synovial fluid, despite significant frequencies in the circulation. Strikingly, the dominant TCR-Vbeta subsets of CD4+CD28null T cells in peripheral blood were often absent in synovial fluid. CD4+CD28null T cells in blood and synovial fluid showed specificity for HCMV antigens, and their presence was clearly associated with HCMV seropositivity but not with anti-citrullinated protein antibodies in the serum or synovial fluid, nor with erosive disease. Together these data imply a primary role for CD4+CD28null T cells in manifestations elsewhere than in the joints of patients with HCMV-seropositive rheumatoid arthritis.  相似文献   
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The Aspergillus nidulans NIMX(CDC2) protein kinase has been shown to be required for both the G(2)/M and G(1)/S transitions, and recent evidence has implicated a role for NIMX(CDC2) in septation and conidiation. While much is understood of its G(2)/M function, little is known about the functions of NIMX(CDC2) during G(1)/S, septation, and conidiophore development. In an attempt to better understand how NIMX(CDC2) is involved in these processes, we have isolated four extragenic suppressors of the A. nidulans nimX2(cdc2) temperature-sensitive mutation. Mutation of these suppressor genes, designated snxA-snxD for suppressor of nimX, affects nuclear division, septation, and conidiation. The cold-sensitive snxA1 mutation leads to arrest of nuclear division during G(1) or early S. snxB1 causes hyperseptation in the hyphae and sensitivity to hydroxyurea, while snxC1 causes septation in the conidiophore stalk and aberrant conidiophore structure. snxD1 leads to slight septation defects and hydroxyurea sensitivity. The additional phenotypes that result from the suppressor mutations provide genetic evidence that NIMX(CDC2) affects septation and conidiation in addition to nuclear division, and cloning and biochemical analysis of these will allow a better understanding of the role of NIMX(CDC2) in these processes.  相似文献   
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A report on the XXXV International Congress of Physiological Sciences, held together with Experimental Biology 2005, San Diego, USA, 31 March - 6 April 2005.  相似文献   
28.
The aim of the current research was to determine tomato (Solanum lycopersicum L.) microbiological quality produced under greenhouse conditions in 5 municipalities of the State of Mexico. Studies were conducted during the 2013 production cycle to know the risks and apply prevention strategies prior to its consumption. A microbiological analysis of samples of irrigation water, soil and 100 tomato fruits variety cid was performed to determine Aerobic Mesophiles, Total Coliforms and Fecal Coliforms. The methodology used were those according to the Official Mexican Standards NOM- 109-SSA1-1994, NOM-110-SSA1-1994, NOM-092-SSA1-1994, NOM-113-SSA1-1994, and the Regulations of the National French Organization for Standardization (AFNOR) NF V08-60, and NOM-093-SSA1-1994, which establish the allowable limits for the study microorganisms. The results showed a zero level of pollution in water and soil samples. For fruits, levels of Aerobic Mesophilic were within the maximum limits permitted by the standards. The municipality of Texcaltitlan showed the highest average for these microorganisms (10083.80 CFU/mL). Huixquilucan showed 2266.84 CFU/mL for Total Coliforms. For Fecal Coliforms, municipalities of Coatepec and Texcaltitlan exceeded the allowed limit.  相似文献   
29.
Dow JA  Lee JM 《Genome biology》2005,6(8):335-3
A report on the XXXV International Congress of Physiological Sciences, held together with Experimental Biology 2005, San Diego, USA, 31 March - 6 April 2005.  相似文献   
30.

Background  

Escherichia coli strains are commonly found in the gut microflora of warm-blooded animals. These strains can be assigned to one of the four main phylogenetic groups, A, B1, B2 and D, which can be divided into seven subgroups (A0, A1, B1, B22, B23, D1 and D2), according to the combination of the three genetic markers chuA, yjaA and DNA fragment TspE4.C2. Distinct studies have demonstrated that these phylo-groups differ in the presence of virulence factors, ecological niches and life-history. Therefore, the aim of this work was to analyze the distribution of these E. coli phylo-groups in 94 human strains, 13 chicken strains, 50 cow strains, 16 goat strains, 39 pig strains and 29 sheep strains and to verify the potential of this analysis to investigate the source of fecal contamination.  相似文献   
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