Quantitative determination and reversible modification of sulfhydryl groups in low and high molecular weight compounds using a biradical spin marker]

A new method for quantitation of sulfhydryl groups of low and high molecular weight compounds is proposed. The method is based on the use of a biradical spin label carrying a disulfide bond, RS-SR, where R is the imidazoline radical. It was found that this biradical is involved in the reaction of thiol-disulfide exchange with thiols; the EPR spectra of the original biradical and monoradical products differ essentially. This circumstance made it possible to determine the bimolecular rate constant for the biradical interaction with cysteamine, cysteine, glutathione and human serum albumin. The method was used for measuring glutathione and cysteine levels in murine and rat blood and for assaying the insect acetylcholine esterase activity and reversible inhibition of NADPH-cytochrome P-450 reductase. The method is marked for a high sensitivity (10(-6)-10(-7) M) towards sulfhydryl groups and allows the determination of thiol groups in coloured and nontransparent solutions.     

The immunomodulation of the natural killer activity of the splenocytes in C3HA mice during hepatoma 22a growth

A single injection of C3HA mice with various immunomodulators-ds-RNA, thymogene (TM) and cyclophosphamide (CY)--performed one day before transplantation of syngeneic hepatoma 22a cells led to a decrease in the tumor growth rate. The most prominent effect was found following the CY treatment. The NK cell activity estimated per spleen of mice treated with ds-RNA and TM was seen increased in comparison with the control mice not given the modulators. The rate of tumor growth was due probably to this fact. The protective effect of CY may be accounted for by a direct action of this agent on tumor cells.     

Species loss of stoneflies (Plecoptera) in the Czech Republic during the 20th century

1. Rapid expansion and intensification of anthropogenic activities in the 20th century has caused profound changes in freshwater assemblages. Unfortunately, knowledge of the extent and causes of species loss (SL) is limited due to the lack of reliable historical data. An unusual data set allows us to compare changes in the most sensitive of aquatic insect orders, the Plecoptera, at some 170 locations in the Czech Republic between two time periods, 1955–1960 and 2006–2010. Historical data (1890–1911) on assemblages of six lowland rivers allow us to infer even earlier changes. 2. Regional stonefly diversity decreased in the first half of the 20th century. Streams at lower altitudes lost a substantial number of species, which were never recovered. In the second half of the century, large‐scale anthropogenic pressure caused SL in all habitats, leading to a dissimilarity of contemporary and previous assemblages. The greatest changes were found at sites affected by organic pollution and a mixture of organic pollution and channelisation or impoundment. Colonisation of new habitats was observed in only three of the 80 species evaluated. 3. Species of moderate habitat specialisation and tolerance to organic pollution were most likely to be lost. Those with narrow specialisations in protected habitats were present in both historical and contemporary collections. 4. Contemporary assemblages are the consequence of more than a 100 years of anthropogenic impacts. In particular, streams at lower altitude and draining intensively exploited landscapes host a mere fragment of the original species complement. Most stonefly species are less frequently present than before, although their assemblages remain almost intact in near‐natural mountain streams. Our analyses demonstrate dramatic restriction of species ranges and, in some cases, apparent changes in altitudinal preference throughout the area.     

Variability and phylogenetic relationships of the Cucumis sativus L. species inferred from NBS profiling and RAPD analysis

Genetic variability of the Cucumis sativus species and its phylogenetic relationsips with other species of the genus were studied on the basis of RAPD marking and analysis of intra- and interspecific polymorphism of the nucleotide sequences of the NBS-LRR gene family in species of the genus Cucumis with the use of the NBS profiling method. According to RAPD analysis, cucumber cultivars from different geographic regions are highly similar, except for accessions k-3835 and k-3833 from Afghanistan. NBS profiling analysis revealed phylogenetically most distinct accessions expected to be characterized by specificity of resistance: k-3845 from Uzbekistan, k-3851 from Kyrgyzstan, line 701, k-3835 and k-3833 from Afghanistan, k-2757 and k-3079 from Netherlands, vr.k. 908 from Canada, k-2926 from Bulgaria, Russian cultivars Monastyrskii, Izyashchnyi, and Lel'. Three essentially different groups of species were distinguished, and the C. sativus species (subgenus Cucumis) was found to be distant from the species belonging to the subgenus Melo.     

An unusual presentation of a malignant jejunal tumor and a different management strategy

BACKGROUND: Malignant small bowel tumors are very rare and leiomyosarcoma accounts for less than 15% of the cases. Management of these tumors is challenging in view of nonspecific symptoms, unusual presentation and high incidence of metastasis. In this case report, an unusual presentation of jejunal sarcoma and management of liver metastasis with radiofrequency ablation (RFA) is discussed. CASE PRESENTATION: A 45-year-old male presented with anemia and features of small bowel obstruction. Operative findings revealed a mass lesion in jejunum with intussusception of proximal loop. Resection of bowel mass was performed. Histopathological findings were suggestive of leiomyosarcoma. After 3-years of follow-up, the patient developed recurrence in infracolic omentum and a liver metastasis. The omental mass was resected and liver lesion was managed with radiofrequency ablation. CONCLUSION: Jejunal leiomyosarcoma is a rare variety of malignant small bowel tumor and a clinical presentation with intussusception is unusual. We suggest that an aggressive management approach using a combination of surgery and a newer technique like RFA can be attempted in patients with limited metastatic spread to liver to prolong the long-term survival in a subset of patients.     

Moderate alcohol consumption is associated with better endothelial function: a cross sectional study

Background

Natural heterologous valved conduits with a diameter greater than 22 mm that can be used for right ventricular outflow tract reconstruction in adults are not commercially available. The purpose of this study was to measure by ultrasonography the maximum diameter of the distended jugular veins of horses and cattle, respectively, to identify a population of animals that would be suitable for post-mortem collection of jugular veins at sizes greater than 22 mm.

Methods

The study population included 60 Warmblood horses, 25 Freiberger horses, 20 Brown Swiss cows, and 20 Holstein cows (including 10 Holstein and 10 Red Holstein). The maximum cross-sectional diameter of the distended jugular veins was measured at a location half-way between the mandibular angle and the thoracic inlet. The thoracic circumference (heart girth length) was used as a surrogate of body size. The jugular vein diameters of the different populations were compared by analysis of variance and the association between heart girth length and jugular vein diameter was determined in each of the four study populations by linear regression analysis.

Results

There was considerable individual variation of jugular vein diameters within each of the four study populations. There was no statistically significant relationship between thoracic circumference and jugular vein diameter in any of the populations. The jugular vein diameters of Brown Swiss cows were significantly larger than those of any of the other populations. Warmblood horses had significantly larger jugular vein diameters compared to Freiberger horses.

Conclusion

The results of this study suggest that the production of bovine or equine xenografts with diameters of greater than 22 mm would be feasible. Differences between species and breeds need to be considered. However, prediction of the jugular vein diameter based on breed and heart girth length in an individual animal is inaccurate.     

Activity‐induced dental modification in holocene siberian hunter‐fisher‐gatherers

The use of teeth as tools provides clues to past subsistence patterns and cultural practices. Five Holocene period hunter‐fisher‐gatherer mortuary sites from the south‐western region of Lake Baikal, Siberia, Russian Federation, are observed for activity‐induced dental modification (AIDM) to further characterize their adaptive regimes. Grooves on the occlusal surfaces of teeth are observed in 25 out of 123 individuals (20.3%) and were most likely produced during the processing of fibers from plants and animals, for making items such as nets and cordage. Regional variation in the frequency of individuals with occlusal grooves is found in riverine versus lakeshore sites. This variation suggests that production of material culture items differed, perhaps in relation to different fishing practices. There is also variation in the distribution of grooves by sex: grooves are found predominately in females, except at the Late Neolithic‐Bronze Age river site of Ust'‐Ida I where grooves are found exclusively in males. Occlusal grooves were cast using polyvinylsiloxane and maxillary canine impressions were examined by scanning electron microscopy (SEM) to determine striation patterns. Variation in striae orientation suggests that a variety of activities, and/or different manufacturing techniques, were involved in groove production. Overall, the variability in occlusal groove frequency, sex and regional distribution, and microscopic striae patterns, points to the multiplicity of activities and ways in which people used their mouths and teeth in cultural activities. Am J Phys Anthropol 143:266–278, 2010. © 2010 Wiley‐Liss, Inc.     

Change of the hereditary properties of Amoeba proteus during micrurgic intervention at the time of mitosis (metaphase ane early anaphase)]

Studies have been made on viability and hereditary properties of the progeny of amoebae after micrurgical coercions (sectioning of cells, suction of cytoplasm) during metaphase and early anaphase. The progeny of the fragments as well as of the cells with the reduced bulk of the cytoplasm exhibits unusual methionine resistance. Possible mechanism of the observed phenomemon are discussed.     

Characterization of the Bellevalia sarmatica (Georgi) woronow populations from Volgograd oblast using molecular genetic identification

DNA samples obtained from the populations of the Red Data Book species Bellevalia sarmatica (Georgi) Worovow from Volgograd oblast were examined using RAPD and AFLP analyses. DNA marking revealed considerable differences in the levels of interpopulation and intraspecific polymorphism of the Bellevalia. Furthermore, RAPD analysis, despite of lower levels of interpopulation polymorphism identified, made it possible to obtain clearer data on population subdivision upon statistical treatment of the results. The results of this study can be used in developing conservation strategies for maintenance of the species abundance and genetic diversity, as well as in elaborating the criteria for construction genetic collections.