Three-dimensional arrangement of dense connective tissue around the human major duodenal papilla. Including the ampullary region and the distal choledochal duct

Directionally arranged dense connective tissue fibres were investigated in 21 specimens of the major duodenal papilla. Specimens were examined using a stereoscope, polarization microscopy and serial histological sections at three different planes. Directionally arranged dense connective tissue fibres spread in a deltoid pattern from the orifice of the major duodenal papilla and its intraduodenal part to the circular duodenal musculature. Connective tissue fibres crossing at different angles form a texture from the orifice of the major duodenal papilla to the distal choledochal duct. The functional significance of the dense connective tissue fibres, e.g. for the muscular system in the investigated area, is discussed as well as possible reasons for gallstone impactions.     

Influence of cryopreservation on the pulpal tissue of immature third molars in vitro

The purpose of this study was to evaluate in vitro the viability of isolated and non-isolated pulpal tissue of immature third molars after cryopreservation. This study was divided in three different experiments. Experiment 1: Pulpal tissue isolated from 19 third molars was divided in horizontal segments. Each segment was cultured separately in order to evaluate whether differences in growth capacity within the tissue could be found. Experiment 2: Pulpal tissue isolated from 27 third molars was divided in a mesial and a distal part. One part was cryopreserved before culturing, the other part was cultured immediately. Growth capacity of cryopreserved and non-cryopreserved tissue was evaluated and compared. Experiment 3: 43 third molars were cryopreserved. After thawing, the dimension of the apical foramen was measured and the pulp was isolated and segmented horizontally. The different parts were cultured and growth capacity was evaluated and compared. Results of experiment 1 and 2 showed no significant difference in growth capacity between fibroblasts originating from different pulpal segments of the same tooth without cryopreservation and between fibroblasts originating from cryopreserved and non-cryopreserved isolated pulpal tissue. In experiment 3 it was demonstrated that the dimension of the apical foramen and pulpal viability after cryopreservation are positively correlated. A minimum dimension of 9.42 mm2 enables the cryoprotective agent to penetrate sufficiently and to protect the pulpal tissue from apex to crown. This study proved that cryopreservation of human pulpal tissue is possible if the cryoprotective agent can reach the entire pulp.     

不同部位喉黏膜间充质细胞的分离培养

目的:探讨不同部位喉黏膜间充质细胞的分离、培养方法,为喉部组织工程提供更多的可供选择的种子细胞。方法:收集临床上喉部手术病人切下的不同部位的喉黏膜,主要是会厌的背侧黏膜和声带的黏膜,各3例,共计6例。对会厌背侧的黏膜采用消化培养的方法,对声带部位的黏膜采用组织块培养法。最后通过免疫荧光染色对两种方法所获得的细胞进行鉴定,确定其来源于喉黏膜的间充质。结果:通过两种方法均可以成功获得相应部位的细胞,免疫荧光染色vimentin均呈阳性表达且CK均呈阴性表达,证明了获得的细胞确实是来源于间充质。结论:本实验成功的培养出了喉部不同部位的间充质细胞,为喉部的组织工程提供了更多的可供选择的种子细胞。     

不同部位喉黏膜间充质细胞的分离培养

目的：探讨不同部位喉黏膜间充质细胞的分离、培养方法,为喉部组织工程提供更多的可供选择的种子细胞。方法：收集临床上喉部手术病人切下的不同部位的喉黏膜,主要是会厌的背侧黏膜和声带的黏膜,各3例,共计6例。对会厌背侧的黏膜采用消化培养的方法,对声带部位的黏膜采用组织块培养法。最后通过免疫荧光染色对两种方法所获得的细胞进行鉴定,确定其来源于喉黏膜的间充质。结果：通过两种方法均可以成功获得相应部位的细胞,免疫荧光染色vimentin均呈阳性表达且CK均呈阴性表达,证明了获得的细胞确实是来源于间充质。结论：本实验成功的培养出了喉部不同部位的间充质细胞,为喉部的组织工程提供了更多的可供选择的种子细胞。     

On the histochemistry of epimerases

Summary A histochemical method for hydroxyproline epimerase together with its mechanism of enzymatic action is described. The epimerase is studied in different tissues and organs. The data resulting from the investigation reveal a particular epimerase activity in connective tissue and skeletal muscular tissue.     

The influence of tissue section thickness on the study of collagen by the Picrosirius-polarization method

Summary The influence of tissue section thickness on the color and intensity of birefringence displayed by collagen in tissue sections studied by means of the Picrosirius-polarization method, is reported in this paper. When dermal collagen sections of different thicknesses (ranging from 0.25 to 11 m) were studied by this method, it became evident that not only did the intensity of birefringence increase proportionally to tissue section thickness, as was to be expected, but also a gradual shift in color from green through yellow to red could be observed as tissue section thickness increased. The limitations of the Picrosirius-polarization method for the localization of collagen types I, II, and III in routinely used histological slides is discussed, showing that this method is useful for the study of the distribution of the different types of interstitial collagen in normal adult vertebrate organs.     

Comparison of homogenization with the GentleMacs Dissociator vs conventional methods for routine tissue processing

Tissue specimens are valuable materials for microbiological diagnosis. The method of tissue processing can have a significant effect on sensitivity. This study aimed to compare different biopsy processing methods in terms of efficacy and standardization. Pork tissue artificially inoculated with Staphylococcus aureus and Escherichia coli, and samples of infected human tissue were processed by different methods before culture, and the results compared. Bacterial recovery from artificially inoculated pork tissue was significantly higher by homogenization with GentleMacs Dissociator than with sonication. No significant difference was observed between the GentleMacs Dissociator and manual treatment with a scalpel and vortexing. The microbial yield from homogenized human tissues was significantly higher after homogenization with GentleMacs Dissociator than with the conventional method. Homogenization with the GentleMacs Dissociator retrieves bacteria from tissue effectively. Tissue homogenization with the Dissociator is easy and fast to perform and allows for a high degree of standardization.     

On the dependence of the elasticity and strength of cancellous bone on apparent density

This paper presents a statistical analysis of the pooled data from a number of previous experiments concerning the dependence of the Young's moduli and strength of cancellous bone tissue upon apparent density. The results show that both the Young's moduli and the strength are proportional to the square of apparent density of the tissue and are therefore proportional to one another. It is shown that the coefficient of proportionality is different for human and bovine tissue. It is concluded that the suggestion of Wolff (Das Gesetz der Transformation der Knochen, Hirschwald, Berlin, 1892) that compact bone tissue is simply more dense cancellous bone tissue is not an accurate statement when only the mechanical properties of these two tissues are considered. It is noted that estimates for the elastic modulus of the individual trabecula of human cancellous bone vary from 1 to 20 GPa and it is suggested that this question needs further study.     

狭叶柴胡各器官结构与其分泌道的分布规律

采用石蜡切片法对狭叶柴胡全株不同器官的结构及各器官中分泌道的分布特征进行了解剖学观察研究.结果表明:(1)狭叶柴胡的主根从外向内由周皮、中柱鞘薄壁细胞环和次生维管组织组成,其中柱鞘薄壁细胞环是不同于一般双子叶植物根的一种结构;茎从外到内由表皮、皮层和维管柱组成;叶为等面叶,其上、下表皮内都具栅栏组织;花主要由花瓣、雄蕊...     

Mathematical modeling of the malignancy of cancer using graph evolution

We report a novel computational method based on graph evolution process to model the malignancy of brain cancer called glioma. In this work, we analyze the phases that a graph passes through during its evolution and demonstrate strong relation between the malignancy of cancer and the phase of its graph. From the photomicrographs of tissues, which are diagnosed as normal, low-grade cancerous and high-grade cancerous, we construct cell-graphs based on the locations of cells; we probabilistically generate an edge between every pair of cells depending on the Euclidean distance between them. For a cell-graph, we extract connectivity information including the properties of its connected components in order to analyze the phase of the cell-graph. Working with brain tissue samples surgically removed from 12 patients, we demonstrate that cell-graphs generated for different tissue types evolve differently and that they exhibit different phase properties, which distinguish a tissue type from another.     

Altered chromatin structure associated with a partial trisomy of chromosome 7 in the mouse

The chromatin of a mouse that is trisomic for part of chromosome 7 was investigated. Chromatin from trisomic tissue has a smaller average nucleosome DNA repeat length than chromatin from tissue taken from normal diploid littermates. DNA of the nucleosome cores is the same size in both normal and trisomic tissues. Not all of the nucleosome monomers have different repeat lengths. Normal and trisomic mouse kidney cells in tissue culture maintained their nucleosome repeat-length differences.     

Mosaic Structure of the Human Immunodeficiency Virus Type 1 Genome Infecting Lymphoid Cells and the Brain: Evidence for Frequent In Vivo Recombination Events in the Evolution of Regional Populations

In addition to immunodeficiency, human immunodeficiency virus type 1 (HIV-1) can cause cognitive impairment and dementia through direct infection of the brain. To investigate the adaptive process and timing of HIV-1 entry into the central nervous system, we carried out an extensive genetic characterization of variants amplified from different regions of the brain and determined their relatedness to those in lymphoid tissue. HIV-1 genomes infecting different regions of the brain of one study subject with HIV encephalitis (HIVE) had a mosaic structure, being assembled from different combinations of evolutionarily distinct lineages in p17(gag), pol, individual hypervariable regions of gp120 (V1/V2, V3, V4, and V5), and gp41/nef. Similar discordant phylogenetic relationships were observed between p17(gag) and V3 sequences of brain and lymphoid tissue from three other individuals with HIVE. The observation that different parts of the genome of HIV infecting a particular tissue can have different evolutionary histories necessarily limits the conclusions that can be drawn from previous studies of the compartmentalization of distinct HIV populations in different tissues, as these have been generally restricted to sequence comparisons of single subgenomic regions. The complexity of viral populations in the brain produced by recombination could provide a powerful adaptive mechanism for the spread of virus with new phenotypes, such as antiviral resistance or escape from cytotoxic T-cell recognition into existing tissue-adapted virus populations.     

A note on the production and use of antisera for the detection of part-digested sticklebacks in predator stomach-content samples

Preliminary experiments indicate that serological techniques provide a useful method of identifying specific prey antigens from the stomach contents of fish predators. Problems with cross-reacting antigens from different prey species can be reduced by absorbing anti-sera with tissue extracts of the cross-reacting species. Very small volumes of part-digested prey tissue are sufficient for identification of the prey species when using agarose diffusion plates (Ouchterlony tests).     

Analysis of the effects of deep mechanical massage in the porcine model.

Deep mechanical massage has been advocated as an alternative or adjunctive therapy for the contouring of subcutaneous fat and as a treatment for cellulite. We evaluated the effects of deep mechanical massage using two pig models. Yucatan pigs were divided into three groups (n = 4). One side of each body received 4, 10, or 20 treatments and the other side served as a control. Full-thickness tissue sections, including the underlying muscle, were harvested from identical treated and untreated regions. Examination of these regionally matched samples revealed an accumulation of dense, longitudinal collagen bands in the middle dermal and deep subdermal regions, which progressively increased with the number of treatments. Distortion and disruption of adipocytes was noted. In Yorkshire pigs, force-transducing balloon catheters were surgically placed between the deep subcutaneous tissue and muscle fascia. Catheters were inserted into two regions with different skin and subcutaneous tissue characteristics, the midflank and the hip. Standardized maneuvers were performed at suction settings 3, 5, 7, and 9 to record baseline tissue forces. Each maneuver carried a unique force signature. The measurement of tissue forces was repeated on the opposite side after 10 standardized treatment sessions. Analysis showed a significant reduction of measured forces at the midflank after the treatments. The actual force measured with each particular maneuver varied between different operators but not with different suction settings, suggesting that the technique of administering the treatments is the primary factor in creating the force within the tissue. This leads to the conclusion that deep mechanical massage is highly dependent on the individual operator of the device.     

Differential expression of Thy-1 on the various components of connective tissue of rat nerve during postnatal development

The glycoprotein Thy-1 is found on the surface of both neurons, and most fibroblasts, in tissue culture of embryonic or neonatal rat nervous tissue. In adult rat nerves, however, we find the antigen restricted in vivo to neurons and their axons (R. Morris, P. Barber, J. Beech, and G. Raisman, 1983, J. Neurocytol., 12, 1017-1039). We show here that this discrepancy is due to a loss of Thy-1 from neural connective tissue during postnatal development. Moreover, the different elements of connective tissue loose Thy-1 at different times. Epineurial fibroblasts, for instance, express Thy-1 for at least 2 weeks after endoneurial fibroblasts lack detectable antigen. As judged by their loss of Thy-1 antigen, therefore, the different components of neural connective tissue mature at different rates. One important practical implication of this is that Thy-1 cannot be used as a cell surface "marker" for all classes of fibroblasts in vitro. Unusual problems encountered in the immunohistochemical staining of Thy-1 on perineurium, but not on the other elements of the nerve, are also described.     

Preservation of ranking order in the expression of human Housekeeping genes

Housekeeping (HK) genes fulfill the basic needs for a cell to survive and function properly. Their ubiquitous expression, originally thought to be constant, can vary from tissue to tissue, but this variation remains largely uncharacterized and it could not be explained by previously identified properties of HK genes such as short gene length and high GC content. By analyzing microarray expression data for human genes, we uncovered a previously unnoted characteristic of HK gene expression, namely that the ranking order of their expression levels tends to be preserved from one tissue to another. Further analysis by tensor product decomposition and pathway stratification identified three main factors of the observed ranking preservation, namely that, compared to those of non-HK (NHK) genes, the expression levels of HK genes show a greater degree of dispersion (less overlap), stableness (a smaller variation in expression between tissues), and correlation of expression. Our results shed light on regulatory mechanisms of HK gene expression that are probably different for different HK genes or pathways, but are consistent and coordinated in different tissues.     

Distribution of Bacteria within the Tissue of Healthy Tomatoes

Bacteria have been shown to be present in fresh normal tomatoes. The frequency of their presence differed widely between different fields. Bacterial populations within the tomatoes showed a distinct gradient, being largest in the connective tissue at the stem end and decreasing through the central core towards the peripheral and distal tissue. Application of Serratia to the sepals of young tomato fruits often resulted in their recovery from within tissue of the mature fruit. These findings lend support to the theory that the bacteria enter the fruit through the connective tissue at the stem end.     

Effect of insulin on the adipose tissue of patients with diabetes mellitus]

A study was made of insulin sensitivity of the adipose tissue biopsied in 11 healthy women, and in 10 women with normal weight suffering from newly-detected diabetes mellitus. In difference from healthy persons in the adipose tissue of patients suffering from diabetes, insulin in a concentration of 50 mu/ml failed to enhance the oxidation of glucose to CO2, and in a concentration of 50 and 100 mu/ml failed to enhance the glycogen synthesis from glucose. Reduction of the sensitivity of different ways of glucose metabolism in the adipose tissue to insulin in patients suffering from diabetes mellitus pointed to the possibility of disturbance of insulin interaction with the cell membrane in this disease.     

Readdressing the issue of thermally significant blood vessels using a countercurrent vessel network

A physiologically realistic arterio-venous countercurrent vessel network model consisting of ten branching vessel generations, where the diameter of each generation of vessels is smaller than the previous ones, has been created and used to determine the thermal significance of different vessel generations by investigating their ability to exchange thermal energy with the tissue. The temperature distribution in the 3D network (8178 vessels; diameters from 10 to 1000 microm) is obtained by solving the conduction equation in the tissue and the convective energy equation with a specified Nusselt number in the vessels. The sensitivity of the exchange of energy between the vessels and the tissue to changes in the network parameters is studied for two cases; a high temperature thermal therapy case when tissue is heated by a uniformly distributed source term and the network cools the tissue, and a hypothermia related case, when tissue is cooled from the surface and the blood heats the tissue. Results show that first, the relative roles of vessels of different diameters are strongly determined by the inlet temperatures to those vessels (e.g., as affected by changing mass flow rates), and the surrounding tissue temperature, but not by their diameter. Second, changes in the following do not significantly affect the heat transfer rates between tissue and vessels; (a) the ratio of arterial to venous vessel diameter, (b) the diameter reduction coefficient (the ratio of diameters of successive vessel generations), and (c) the Nusselt number. Third, both arteries and veins play significant roles in the exchange of energy between tissue and vessels, with arteries playing a more significant role. These results suggest that the determination of which diameter vessels are thermally important should be performed on a case-by-case, problem dependent basis. And, that in the development of site-specific vessel network models, reasonable predictions of the relative roles of different vessel diameters can be obtained by using any physiologically realistic values of Nusselt number and the diameter reduction coefficient.     

The chemical composition of plant galls: are levels of nutrients and secondary compounds controlled by the gall-former?

The chemical composition of galled and ungalled plant tissue was compared in a series of experiments. Gall and adjacent plant tissue was analysed for 20 species of gall-former on 11 different plant species. There were clear differences between galled and ungalled tissue in levels of nutrients and secondary compounds. Gall tissue generally contained lower levels of nitrogen and higher levels of phenolic compounds than ungalled plant tissue. The gall tissue produced by the same plant in response to different species of gall-former differed in chemical composition, as did the gall-tissue from young and mature galls of the same species. The chemical differences between gall and plant tissues were studied in more detail in two field manipulations. Firstly, the seasonal changes in phenolic biosynthesis in Pontania proxima and P. pedunculi (Hymenoptera: Tenthredinidae) gall tissue were compared to those of their host plants, Salix alba and S. caprea. In both types of gall tissue, phenolic levels declined as the season progressed, but levels in the surrounding plant tissue increased. When the gall insects were killed with insecticide, phenolic levels in the galled tissue dropped to the same level as those in adjacent plant tissue. Secondly, the density of Cynips divisa (Hymenoptera: Cynipidae) galls on Quercus robur leaves was reduced by removing half the galls present, either those from the central region of the leaf or those from the edge. Decreasing gall density increased the size of the remaining galls and the weight of the insects, but these effects were most marked when the galls remaining were growing centrally on the leaf, i.e. when the galls from the edge had been removed. Decreasing gall density increased the nitrogen content of the remaining galls, again to a greater extent in galls growing centrally on the leaf. The results of these studies suggest that the levels of nutrients and secondary compounds in gall tissue are usually markedly different to those of surrounding plant tissue, and that gall-formers may produce species-specific and temporally variable changes in the chemical composition of gall tissue. Received: 7 July 1997 / Accepted: 29 September 1997