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1.
Ethnic Belarusians make up more than 80% of the nine and half million people inhabiting the Republic of Belarus. Belarusians together with Ukrainians and Russians represent the East Slavic linguistic group, largest both in numbers and territory, inhabiting East Europe alongside Baltic-, Finno-Permic- and Turkic-speaking people. Till date, only a limited number of low resolution genetic studies have been performed on this population. Therefore, with the phylogeographic analysis of 565 Y-chromosomes and 267 mitochondrial DNAs from six well covered geographic sub-regions of Belarus we strove to complement the existing genetic profile of eastern Europeans. Our results reveal that around 80% of the paternal Belarusian gene pool is composed of R1a, I2a and N1c Y-chromosome haplogroups – a profile which is very similar to the two other eastern European populations – Ukrainians and Russians. The maternal Belarusian gene pool encompasses a full range of West Eurasian haplogroups and agrees well with the genetic structure of central-east European populations. Our data attest that latitudinal gradients characterize the variation of the uniparentally transmitted gene pools of modern Belarusians. In particular, the Y-chromosome reflects movements of people in central-east Europe, starting probably as early as the beginning of the Holocene. Furthermore, the matrilineal legacy of Belarusians retains two rare mitochondrial DNA haplogroups, N1a3 and N3, whose phylogeographies were explored in detail after de novo sequencing of 20 and 13 complete mitogenomes, respectively, from all over Eurasia. Our phylogeographic analyses reveal that two mitochondrial DNA lineages, N3 and N1a3, both of Middle Eastern origin, might mark distinct events of matrilineal gene flow to Europe: during the mid-Holocene period and around the Pleistocene-Holocene transition, respectively.  相似文献   
2.

Background

In women with ischemia and no obstructive coronary artery disease, the Women''s Ischemic Syndrome Evaluation (WISE) observed that microvascular coronary dysfunction (MCD) is the best independent predictor of adverse cardiovascular events. Since coronary microvascular tone is regulated in part by endothelium, we hypothesized that circulating endothelial cells (CEC), which reflect endothelial injury, and the number and function of bone-marrow derived angiogenic cells (BMDAC), which could help repair damaged endothelium, may serve as biomarkers for decreased coronary flow reserve (CFR) and MCD.

Methods

We studied 32 women from the WISE cohort. CFR measurements in response to intracoronary adenosine were taken as an index of MCD. We enumerated BMDAC colonies and CEC in peripheral blood samples. BMDAC function was assessed by assay of migration of CD34+ cells toward SDF-1 and measurement of bioavailable nitric oxide (NO). These findings were compared with a healthy reference group and also entered into a multivariable model with CFR as the dependent variable.

Results

Compared with a healthy reference group, women with MCD had lower numbers of BMDAC colonies [16 (0, 81) vs. 24 (14, 88); P = 0.01] and NO [936 (156, 1875) vs. 1168 (668, 1823); P = 0.02]. Multivariable regression analysis showed strong correlation of CFR to the combination of BMDAC colony count and CD34+ cell function (migration and NO) (R2 = 0.45; P<0.05).

Conclusions

The BMDAC function and numbers of BMDAC colonies are decreased in symptomatic women with MCD and are independently associated with CFR. These circulating cells may provide mechanistic insights into MCD in women with ischemia.  相似文献   
3.
The interdisciplinary science of conservation biology provides undergraduate biology students with the opportunity to connect the biological sciences with disciplines including economics, social science and philosophy to address challenging conservation issues. Because of its complexity, students do not often have the opportunity to practise conservation biology. To increase exposure to this science, this paper describes a virtual rainforest island on which students collect data related to forest carbon storage, while also confronting ethical issues. Students are asked to independently make decisions, collect data and explore the island before writing a research report with recommendations for the future management of the island’s forests. The ethics of decision-making are addressed in the students’ research reports and are reinforced through guided class discussion. Students will complete this activity with increased ethical awareness, as well as a better understanding of the challenges associated with the practise of conservation biology.  相似文献   
4.
The synthesis, crystal structure and magnetic properties of manganese(III) binuclear complexes [MnIII2(L-3Н)2(CH3ОH)4]·2CH3ОH (1) and [MnIII2(L-3Н)2(Py)4]·2Py (2) (L = 3-[(1E)-N-hydroxyethanimidoyl]-4-methyl-1H-pyrazole-5-carboxylic acid) are reported. The ligand contains two distinct donor compartments formed by the pyrazolate-N and the oxime or the carboxylic groups. The complexes were characterized by X-ray single crystal diffraction, revealing that both 1 and 2 consist of dinuclear units in which the two metal ions are linked by double pyrazolate bridges with a planar {Mn2N4} core. Cryomagnetic measurements show antiferromagnetic interaction with g = 1.99, J = −3.6 cm−1, Θ = −2.02 K for 1 and g = 2.00, J = −3.7 cm−1, Θ = 1.43 K for 2.  相似文献   
5.
AIM: To investigate the role of protein tyrosine phosphorylation in gastric wound formation and repair following ulceration.METHODS: Gastric lesions were induced in rats using restraint cold stress. To investigate the effect of oxidative and nitrosative cell stress on tyrosine phosphorylation during wound repair, total activity of protein tyrosine kinase (PTK), protein tyrosine phosphatase (PTP), antioxidant enzymes, nitric oxide synthase (NOS), 2’,5’-oligoadenylate synthetase, hydroxyl radical and zinc levels were assayed in parallel.RESULTS: Ulcer provocation induced an immediate decrease in tyrosine kinase (40% in plasma membranes and 56% in cytosol, P < 0.05) and phosphatase activity (threefold in plasma membranes and 3.3-fold in cytosol), followed by 2.3-2.4-fold decrease (P < 0.05) in protein phosphotyrosine content in the gastric mucosa. Ulceration induced no immediate change in superoxide dismutase (SOD) activity, 30% increase (P < 0.05) in catalase activity, 2.3-fold inhibition (P < 0.05) of glutathione peroxidase, 3.3-fold increase (P < 0.05) in hydroxyl radical content, and 2.3-fold decrease (P < 0.05) in zinc level in gastric mucosa. NOS activity was three times higher in gastric mucosa cells after cold stress. Following ulceration, PTK activity increased in plasma membranes and reached a maximum on day 4 after stress (twofold increase, P < 0.05), but remained inhibited (1.6-3-fold decrease on days 3, 4 and 5, P < 0.05) in the cytosol. Tyrosine phosphatases remained inhibited both in membranes and cytosol (1.5-2.4-fold, P < 0.05). NOS activity remained increased on days 1, 2 and 3 (3.8-, 2.6-, 2.2-fold, respectively, P < 0.05). Activity of SOD increased 1.6 times (P < 0.05) days 4 and 5 after stress. Catalase activity normalized after day 2. Glutathione peroxidase activity and zinc level decreased (3.3- and 2-fold, respectively, P < 0.05) on the last day. Activity of 2’,5’-oligoadenylate synthethase increased 2.8-fold (P < 0.05) at the beginning, and 1.6-2.3-fold (P < 0.05) during ulcer recuperation, and normalized on day 5, consistent with slowing of inflammation processes.CONCLUSION: These studies show diverse changes in total tyrosine kinase activity in gastric mucosa during the recovery process. Oxidative and nitrosative stress during lesion formation might lead to the observed reduction in tyrosine phosphorylation during ulceration.  相似文献   
6.
Most commercial probiotic products intended for pharmaceutical applications consist of combinations of probiotic strains and are available in various forms. The development of co‐culture fermentation conditions to produce probiotics with the correct proportion of viable microorganisms would reduce multiple operations and the associated costs. The aim of this study was to develop a fermentation medium and process to achieve biomass comprising the desired proportion of two probiotic strains in co‐culture. Initially, a quantification medium was developed, and the method was optimized to allow the quantification of each strain's biomass in a mixture. The specific growth rates of Lactobacillus delbrueckii spp. bulgaricus and Lactobacillus plantarum were determined in media with different carbon sources. The inoculum volume was optimized to achieve equal proportion of biomass in co‐culture fermentation in test tubes. Next, fermentation was carried out in a 3‐L bioreactor. A biomass concentration of 2.06 g/L, with L. delbrueckii spp. bulgaricus and L. plantarum in the ratio of 47%:53% (by weight), was achieved with concomitant production of 12.69 g/L of lactic acid in 14 h. The results show that with careful manipulation of process conditions, it is possible to achieve the desired proportion of individual strains in the final biomass produced by co‐culture fermentation. This process may serve as a model to produce multistrain probiotic drugs at industrial scale.  相似文献   
7.
Alport disease in humans, which usually results in proteinuria and kidney failure, is caused by mutations to the COL4A3, COL4A4, or COL4A5 genes, and absence of collagen α3α4α5(IV) networks found in mature kidney glomerular basement membrane (GBM). The Alport mouse harbors a deletion of the Col4a3 gene, which also results in the lack of GBM collagen α3α4α5(IV). This animal model shares many features with human Alport patients, including the retention of collagen α1α2α1(IV) in GBMs, effacement of podocyte foot processes, gradual loss of glomerular barrier properties, and progression to renal failure. To learn more about the pathogenesis of Alport disease, we undertook a discovery proteomics approach to identify proteins that were differentially expressed in glomeruli purified from Alport and wild-type mouse kidneys. Pairs of cy3- and cy5-labeled extracts from 5-week old Alport and wild-type glomeruli, respectively, underwent 2-dimensional difference gel electrophoresis. Differentially expressed proteins were digested with trypsin and prepared for mass spectrometry, peptide ion mapping/fingerprinting, and protein identification through database searching. The intermediate filament protein, vimentin, was upregulated ∼2.5 fold in Alport glomeruli compared to wild-type. Upregulation was confirmed by quantitative real time RT-PCR of isolated Alport glomeruli (5.4 fold over wild-type), and quantitative confocal immunofluorescence microscopy localized over-expressed vimentin specifically to Alport podocytes. We next hypothesized that increases in vimentin abundance might affect the basement membrane protein receptors, integrins, and screened Alport and wild-type glomeruli for expression of integrins likely to be the main receptors for GBM type IV collagen and laminin. Quantitative immunofluorescence showed an increase in integrin α1 expression in Alport mesangial cells and an increase in integrin α3 in Alport podocytes. We conclude that overexpression of mesangial integrin α1 and podocyte vimentin and integrin α3 may be important features of glomerular Alport disease, possibly affecting cell-signaling, cell shape and cellular adhesion to the GBM.  相似文献   
8.

Background

It is well-known that tumor exerts nonmetastatic systemic effect on organism caused the development of paraneoplastic syndrome (PNS). Recent findings point to relationships between development of PNS and tumor-derived vascular endothelial growth factor (VEGF).

Aim

Comparative study of PNS manifestations in mice with transplanted two variants of Lewis lung carcinoma with different angiogenic potential.

Methods

Plasma VEGF level was determined by immunoenzyme method, hematological indices were estimated with the use of hematological analyzer, the weight and cellularity of spleen and thymus were registered and histological analysis of tissue section of these organs was performed.

Results

Manifestations of anemia, extramedullary hemopoiesis and tumor-associated inflammatory disease was observed in animals with high angiogenic LLC/R9 variant and was not registered in low angiogenic LLC. The emergence of PNS symptoms correlated with elevated level of circulating VEGF at the early stages of LLC/R9 growth.

Conclusion

Manifestation of the paraneoplastic hematological syndrome most likely is conditioned on the ability of cancer cell to secrete VEGF in a high rate.  相似文献   
9.
Ultrasound-mediated DNA transfer for bacteria   总被引:2,自引:0,他引:2       下载免费PDF全文
In environmental microbiology, the most commonly used methods of bacterial DNA transfer are conjugation and electroporation. However, conjugation requires physical contact and cell–pilus–cell interactions; electroporation requires low-ionic strength medium and high voltage. These limitations have hampered broad applications of bacterial DNA delivery. We have employed a standard low frequency 40 kHz ultrasound bath to successfully transfer plasmid pBBR1MCS2 into Pseudomonas putida UWC1, Escherichia coli DH5α and Pseudomonas fluorescens SBW25 with high efficiency. Under optimal conditions: ultrasound exposure time of 10 s, 50 mM CaCl2, temperature of 22°C, plasmid concentration of 0.8 ng/µl, P. putida UWC1 cell concentration of 2.5 × 109 CFU (colony forming unit)/ml and reaction volume of 500 µl, the efficiency of ultrasound DNA delivery (UDD) was 9.8 ± 2.3 × 10−6 transformants per cell, which was nine times more efficient than conjugation, and even four times greater than electroporation. We have also transferred pBBR1MCS2 into E. coli DH5α and P. fluorescens SBW25 with efficiencies of 1.16 ± 0.13 × 10−6 and 4.33 ± 0.78 × 10−6 transformants per cell, respectively. Low frequency UDD can be readily scaled up, allowing for the application of UDD not only in laboratory conditions but also on an industrial scale.  相似文献   
10.
Sox2 is expressed in developing foregut endoderm, with highest levels in the future esophagus and anterior stomach. By contrast, Nkx2.1 (Titf1) is expressed ventrally, in the future trachea. In humans, heterozygosity for SOX2 is associated with anopthalmia-esophageal-genital syndrome (OMIM 600992), a condition including esophageal atresia (EA) and tracheoesophageal fistula (TEF), in which the trachea and esophagus fail to separate. Mouse embryos heterozygous for the null allele, Sox2(EGFP), appear normal. However, further reductions in Sox2, using Sox2(LP) and Sox2(COND) hypomorphic alleles, result in multiple abnormalities. Approximately 60% of Sox2(EGFP/COND) embryos have EA with distal TEF in which Sox2 is undetectable by immunohistochemistry or western blot. The mutant esophagus morphologically resembles the trachea, with ectopic expression of Nkx2.1, a columnar, ciliated epithelium, and very few p63(+) basal cells. By contrast, the abnormal foregut of Nkx2.1-null embryos expresses elevated Sox2 and p63, suggesting reciprocal regulation of Sox2 and Nkx2.1 during early dorsal/ventral foregut patterning. Organ culture experiments further suggest that FGF signaling from the ventral mesenchyme regulates Sox2 expression in the endoderm. In the 40% Sox2(EGFP/COND) embryos in which Sox2 levels are approximately 18% of wild type there is no TEF. However, the esophagus is still abnormal, with luminal mucus-producing cells, fewer p63(+) cells, and ectopic expression of genes normally expressed in glandular stomach and intestine. In all hypomorphic embryos the forestomach has an abnormal phenotype, with reduced keratinization, ectopic mucus cells and columnar epithelium. These findings suggest that Sox2 plays a second role in establishing the boundary between the keratinized, squamous esophagus/forestomach and glandular hindstomach.  相似文献   
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