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1.
The electrophoretical polymorphisms of some blood proteins were studied in the Talysh population of Pirasora situated in South-East Azerbaidjan. We calculated the gene frequencies of these polymorphisms and determined the genetic distances between the Talyshes and some Iranian populations of North, Central and South Iran, Afghans, and three populations of Azerbaijan. The Talyshes are very close to Iranians of Shiraz, whereas they are distant from the Azerbaijanians. Anthropological investigations showed that the Caucasoids and Mongoloids lived in the Aragvi Basin since the Eneolithic period. This was stated by Alexeev (1974), who emphasized the mixture of the Caucasus populations from ancient times on. We calculated the genetic distances between the Caucasus populations and numerous populations of other geographic regions, considering 28 alleles of 12 loci of blood group, serum protein and red cell enzyme polymorphisms and constructed the dendrogram of these populations. The position of the Caucasus populations in the dendrogram corresponds on principle to the earlier anthropological observations. The clustering of the Caucasoid populations corresponds completely with anthropological and historical data, and supports our earlier hypothesis (Nazarova 1999) concerning the differentiation of Caucasoids, Northern Mongoloids and Amerinds from the populations, which inhabitated Asia in palaeolithic times.  相似文献   

2.
In order to analyze the complicated movements of the mandible as the open-closing movement and the protrusio are, it is useful to evaluate the basic kinematic principles and reduce them to simple technical constructions. Both the open-closing movement and the protrusio could be reduced to 4-bar links, which were used to simulate the movements with help of a computer. Besides, the polodes and the curves of points in the muscular attachments could be constructed. The 2 entirely different 4-bar links have 3 things in common: The resting system - cranium, the moving system - mandibula, and 1 of the 2 arms connecting these 2 systems - the ligamentum laterale. As this ligament is taut during movements it can be considered a "guiding ligament" representing 1 of the 3 determining components of the mandibular movements. The other of the 2 arms has no anatomical equivalent; this arm, however, is "replaced" by the 2 other determining components of the mandibular movements: the joint and the muscles. The curves, which the Caput mandibulae describes, are practically identical for the open-closing movement and the protrusio despite of the different 4-bar links and these curves exactly correspond to the Discus articularis, taut by the upper part of the M. pterygoideus lateralis. The muscles do not only just move the mandibula, but they are also the component, which can choose between the different mandibular movements. By means of the curves, which points in the muscular attachments describe, the function of the masticatory muscles could be analyzed exactly.  相似文献   

3.
Several different models of the linker histone (LH)–nucleosome complex have been proposed, but none of them has unambiguously revealed the position and binding sites of the LH on the nucleosome. Using Brownian dynamics-based docking together with normal mode analysis of the nucleosome to account for the flexibility of two flanking 10 bp long linker DNAs (L-DNA), we identified binding modes of the H5-LH globular domain (GH5) to the nucleosome. For a wide range of nucleosomal conformations with the L-DNA ends less than 65 Å apart, one dominant binding mode was identified for GH5 and found to be consistent with fluorescence recovery after photobleaching (FRAP) experiments. GH5 binds asymmetrically with respect to the nucleosomal dyad axis, fitting between the nucleosomal DNA and one of the L-DNAs. For greater distances between L-DNA ends, docking of GH5 to the L-DNA that is more restrained and less open becomes favored. These results suggest a selection mechanism by which GH5 preferentially binds one of the L-DNAs and thereby affects DNA dynamics and accessibility and contributes to formation of a particular chromatin fiber structure. The two binding modes identified would, respectively, favor a tight zigzag chromatin structure or a loose solenoid chromatin fiber.  相似文献   

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人类基因组及后基因组研究进展及其应用与开发研究现状   总被引:9,自引:0,他引:9  
人类对自身基因组的研究,随着人类基因组工作草图的绘制完成和对基因功能研究的深入已加快进入了实质性、关键性的开发利用阶段。本文概述了人类基因组及后基因组的研究进展及依此开展基因治疗及基因(组)药物研制等应用开发研究的现状。  相似文献   

6.
Interpreting channel behavior in patches requires an understanding of patch structure and dynamics, especially in studies of mechanosensitive channels. High resolution optical studies show that patch formation occurs via blebbing that disrupts normal membrane structure and redistributes in situ components including ion channels. There is a 1-2 μm region of the seal below the patch where proteins are excluded and this may consist of extracted lipids that form the gigaseal. Patch domes often have complex geometries with inhomogeneous stresses due to the membrane-glass adhesion energy (Ea), cytoskeletal forces, and possible lipid subdomains. The resting tension in the patch dome ranges from 1-4 mN/m, a significant fraction of the lytic tension of a bilayer (∼10 mN/m). Thus, all patch experiments are conducted under substantial, and uneven, resting tension that may alter the kinetics of many channels. Ea seems dominated by van der Waals attraction overlaid with a normally repulsive Coulombic force. High ionic strength pipette saline increased Ea and, surprisingly, increased cytoskeletal rigidity in cell-attached patches. Low pH pipette saline also increased Ea and reduced the seal selectivity for cations, presumably by neutralizing the membrane surface charge. The seal is a negatively charged, cation selective, space with a resistance of ∼7 gigohm/μm in 100 mM KCl, and the high resistivity of the space may result from the presence of high viscosity glycoproteins. Patches creep up the pipette over time with voltage independent and voltage dependent components. Voltage-independent creep is expected from the capillary attraction of Ea and the flow of fresh lipids from the cell. Voltage-dependent creep seems to arise from electroosmosis in the seal. Neutralization of negative charges on the seal membrane with low pH decreased the creep rate and reversed the direction of creep at positive pipette potentials.  相似文献   

7.
The systematic position ofthe Ebenaceae, Sapotaceae, Styracaceae, Ochnaceae, Stachyuraceae, Dipterocarpaceae, Clusiaceae and Hypericaceae has been investigated using serological comparisons of sets of antigenic determinants. The results show that the Sytracaceae and Sapotaceae are undoubtedly more closely associated with the Actinidiaeceae and Theaceae, respectively, than with each other. We found no corresponding determinants betnween antigen systems from the Ebenaceae and systems from any other family whose relations to this family have been proposed. As discovered previously, investigations of antigen systems from the Ochnaceae, Dipterocarpaceae, Stachyuraceae, Clusiaceae and Hypericaceae are against the idea of a natural order “Theales” in which these families, or at least some of them, are combined with the Theaceae and Actinidiaceae. This paper completes our previous investigations which largely support a superorder Ericanae sensu Ehrendorfer and Takhtajan. We propose to include the Actinidiaceae and Theaceae in this superorder, assigning them a central position laong with the Sapotaceae and Sytracaeae on one side and the Primulales and Ericales on the other. Another most interesting finding is that there are corresponding determinants between antigen systems from the members of the Ericanae and representatives of the Polemoniaceae and Loasaceae.  相似文献   

8.

Objective

To assess the separate effects of thumb and finger extension/flexion on median nerve position and cross-sectional area.

Methods

Ultrasonography was used to assess median nerve transverse position and cross-sectional area within the carpal tunnel at rest and its movement during volitional flexion of the individual digits of the hand. Both wrists of 165 normal subjects (11 men, 4 women, mean age, 28.6, range, 22 to 38) were studied.

Results

Thumb flexion resulted in transverse movement of the median nerve in radial direction (1.2±0.6 mm), whereas flexion of the fingers produced transverse movement in ulnar direction, which was most pronounced during flexion of the index and middle fingers (3.2±0.9 and 3.1±1.0 mm, respectively). Lesser but still statistically significant movements were noted with flexion of the ring finger (2.0±0.8 mm) and little finger (1.2±0.5 mm). Flexion of the thumb or individual fingers did not change median nerve cross-sectional area (8.5±1.1 mm2).

Conclusions

Volitional flexion of the thumb and individual fingers, particularly the index and middle fingers, produced significant transverse movement of the median nerve within the carpal tunnel but did not alter the cross-sectional area of the nerve. The importance of these findings on the understanding of the pathogenesis of the carpal tunnel syndrome and its treatment remains to be investigated.  相似文献   

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Abstract Earlier papers dealing with the anatomy of the hesionids and syllids were studied. Thereby it was found that information about the structure of the central nervous system was meagre. As a result, the anterior end appendages, especially the large, laterloventral ones of the Syllidae, have been differently interpreted. This prompted a re-investigation. The circum-oesophageal connectives, the brain commissures and the innervation of the alimentary canal and the cephalic appendages of a number of hesionid and syllid species were studied. The results, summarized in schematic diagrams, were compared with corresponding observations in other polychaete families. Among other things, it was concluded that not only the latero-ventral cephalic appendages of the hesionids but also those of the syllids are homologous with the palps of the nereids and of many other “errant” and “sedentary” families.  相似文献   

13.
Treatment of Schistosoma haematobium (Nigerian strain) in hamsters with a single dose of 40 mg/kg of Astiban caused a reduction in the number of S1, S2, and S3 vitelline cells and an increase in S4 cells. Following seven daily doses of the drug, a marked reduction in S1 cells and a complete loss of S2 and S3 cells occurred such that 95% of the cells were S4 cells, all of which were structurally abnormal. Coagulation and disintegration of the protein granules of the vitelline droplets occurred with increase in lipid droplets, swelling of the nuclear membrane and an increase in cytosegresomes. Blebbing of the tegument in both sexes occurred following a single treatment and vacuolation of the basal infolds and alterations to the mitochondria also resulted, but severe erosion of the tegument was rare even following repeated drug treatment. Damage to the gastrodermis was severe with the development of autophagic vacuoles containing whorls of myelin and sequestered portions of damaged tissue. The degree of damage increased with the number of drug treatments.  相似文献   

14.
The archaeal community in the fermentative compartment and faeces of the cow and the rabbit were compared by analysis capillary electrophoresis single-stranded conformation polymorphism (CE-SSCP) profiles of 16S rRNA genes. Ruminal and faecal contents were sampled in five cows for three weeks. Hard and soft faeces were collected in 14 rabbits for three consecutive weeks and cæcal contents were sampled in the third week. The archaeal community differed according to the host species (ANOSIM-R = 0.53 and 0.72 respectively for the comparison of the fermentative compartments and faeces; P < 0.001) and to the location within the digestive tract of both species (ANOSIM-R = 0.37, 0.52 respectively for the cow and the rabbit; P < 0.001). In both species, the archaeal community of the digestive tract was stable over weeks and varied very little between individual animals. The structure (NS) and the richness index (9.9 ± 2.7, 10.1 ± 3.1 respectively, NS) of the archaeal community were similar for the cæcal content and the soft faeces which permitted to use the latter as a representative indicator.  相似文献   

15.
16.
1. The incorporation of orotic acid and of uridine into total RNA was measured in vivo in liver and lung of the Syrian golden hamster. Specific activities of total acid-soluble UMP were measured in both organs. An estimation of the rate of RNA biosynthesis showed that hamster lung synthesizes RNA at about one-half of the rate of that of hamster liver. 2. The apparent K(m) and V(max.) values of a few enzymes involved in pyrimidine biosynthesis were measured in the 100000g supernatants of liver and lung. The apparent K(m) values were very similar in both organs. From the estimated V(max.,) it was concluded that hamster lung cells have less capacity to metabolize orotic acid than have liver cells. 3. A time-response and a dose-response study showed that actinomycin D inhibits pulmonary RNA synthesis as efficiently as hepatic RNA synthesis. 4. Protein synthesis, measured as the incorporation of leucine, was inhibited in both organs 30min after a dose of 2mg of cycloheximide/kg. The dose-response patterns were similar in both liver and lung 3h after cycloheximide. 5. It is concluded that RNA and protein synthesis in vivo in hamster lung are very similar to the corresponding reactions in liver. Alterations of RNA and protein synthesis by toxic agents can therefore be evaluated in lung with a similar approach to that used to study the pathological biochemistry of liver.  相似文献   

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18.
Chromosome despiralization and nucleolus vacuolization have been studied during the oocyte intensive growth. Oocyte and nucleolus growth has been found to stop at the secondary antral follicles with the diameter more than 1000 mkm. Chromosomal and nucleolar activity decreases at this stage. Chromosomes condense and concentrate around the nucleolus and chromatine mass (karyosphere) forms.  相似文献   

19.
The ovary in which a CL was observed by laparoscopy in Finnish Landrace, Tasmanian Merino and Scottish Blackface ewes had no apparent effect on the location of the CL during the succeeding oestrous cycles, on the duration of the associated oestrous cycles, or on the peripheral progesterone concentrations on Days 7 and 11. Although 53% of CL were present in the right ovaries, the difference between the two sides was not significant.  相似文献   

20.
Data on the ontogeny of the posterior haptor of monogeneans were obtained from more than 150 publications and summarised. These data were plotted into diagrams showing evolutionary capacity levels based on the theory of a progressive evolution of marginal hooks, anchors and other attachment components of the posterior haptor in the Monogenea (Malmberg, 1986). 5 + 5 unhinged marginal hooks are assumed to be the most primitive monogenean haptoral condition. Thus the diagrams were founded on a 5 + 5 unhinged marginal hook evolutionary capacity level, and the evolutionary capacity levels of anchors and other haptoral attachement components were arranged according to haptoral ontogenetical sequences. In the final plotting diagram data on hosts, type of spermatozoa, oncomiracidial ciliation, sensilla pattern and protonephridial systems were also included. In this way a number of correlations were revealed. Thus, for example, the number of 5 + 5 marginal hooks correlates with the most primitive monogenean type of spermatozoon and with few sensillae, many ciliated cells and a simple protonephridial system in the oncomiracidium. On the basis of the reviewed data it is concluded that the ancient monogeneans with 5 + 5 unhinged marginal hooks were divided into two main lines, one retaining unhinged marginal hooks and the other evolving hinged marginal hooks. Both main lines have recent representatives at different marginal hook evolutionary capacity levels, i.e. monogeneans retaining a haptor with only marginal hooks. For the main line with hinged marginal hooks the name Articulon-choinea n. subclass is proposed. Members with 8 + 8 hinged marginal hooks only are here called Proanchorea n. superord. Monogeneans with unhinged marginal hooks only are here called Ananchorea n. superord. and three new families are erected for its recent members: Anonchohapteridae n. fam., Acolpentronidae n. fam. and Anacanthoridae n. fam. (with 7 + 7, 8 + 8 and 9 + 9 unhinged marginal hooks, respectively). Except for the families of Articulonchoinea (e.g. Acanthocotylidae, Gyrodactylidae, Tetraonchoididae) Bychowsky's (1957) division of the Monogenea into the Oligonchoinea and Polyonchoinea fits the proposed scheme, i.e. monogeneans with unhinged marginal hooks form one old group, the Oligonchoinea, which have 5 + 5 unhinged marginal hooks, and the other group form the Polyonchoinea, which (with the exception of the Hexabothriidae) has a greater number (7 + 7, 8 + 8 or 9 + 9) of unhinged marginal hooks. It is proposed that both these names, Oligonchoinea (sensu mihi) and Polyonchoinea (sensu mihi), will be retained on one side and Articulonchoinea placed on the other side, which reflects the early monogenean evolution. Except for the members of Ananchorea [Polyonchoinea], all members of the Oligonchoinea and Polyonchoinea have anchors, which imply that they are further evolved, i.e. have passed the 5 + 5 marginal hook evolutionary capacity level (Malmberg, 1986). There are two main types of anchors in the Monogenea: haptoral anchors, with anlages appearing in the haptor, and peduncular anchors, with anlages in the peduncle. There are two types of haptoral anchors: peripheral haptoral anchors, ontogenetically the oldest, and central haptoral anchors. Peduncular anchors, in turn, are ontogenetically younger than peripheral haptoral anchors. There may be two pairs of peduncular anchors: medial peduncular anchors, ontogentically the oldest, and lateral peduncular anchors. Only peduncular (not haptoral) anchors have anchor bars. Monogeneans with haptoral anchors are here called Mediohaptanchorea n. superord. and Laterohaptanchorea n. superord. or haptanchoreans. All oligonchoineans and the oldest polyonchoineans are haptanchoreans. Certain members of Calceostomatidae [Polyonchoinea] are the only monogeneans with both (peripheral) haptoral and peduncular anchors (one pair). These monogeneans are here called Mixanchorea n. superord. Polyonchoineans with peduncular anchors and unhinged marginal hooks are here called the Pedunculanchorea n. superord. The most primitive pedunculanchoreans have only one pair of peduncular anchors with an anchor bar, while the most advanced have both medial and lateral peduncular anchors; each pair having an anchor bar. Certain families of the Articulonchoinea, the Anchorea n. superord., also have peduncular anchors (parallel evolution): only one family, the Sundanonchidae n. fam., has both medial and lateral peduncular anchors, each anchor pair with an anchor bar. Evolutionary lines from different monogenean evolutionary capacity levels are discussed and a new system of classification for the Monogenea is proposed.In agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. EditorIn agreeing to publish this article, I recognise that its contents are controversial and contrary to generally accepted views on monogenean systematics and evolution. I have anticipated a reaction to the article by inviting senior workers in the field to comment upon it: their views will be reported in a future issue of this journal. Editor  相似文献   

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