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1.
Growth of the kidney is a complex process piloted by the collecting duct (CD) ampullae. The dichotomous arborisation and consecutive elongation of this tubular element determines the exact site and time for the induction of nephrons in the overlaying mesenchymal cap condensates. The mechanism by which the CD ampullae find the correct orientation is currently unknown. Recently, we have demonstrated micro-fibres that originate from the basal aspect of the CD ampullae and extend through the mesenchyme to the organ capsule. The micro-fibres are assumed to be involved in the growth and arborisation process of the CD ampulla. Therefore, we have investigated the specific distribution of the micro-fibres during branching morphogenesis. We have also analysed whether the micro-fibres co-localise with extracellular matrix (ECM)-modulating enzymes and whether the co-localisation pattern changes during CD ampulla arborisation. Micro-fibres were detected in all stages of CD ampulla arborisation. Tissue transglutaminase (Tgase2) co-localised with soybean agglutinin (SBA)-positive micro-fibres, whose presence depended upon the degree of CD branching. Matrix metalloproteinase-9 (MMP-9) also co-localised with micro-fibres, but its expression pattern was different from that for Tgase2. Western blotting experiments demonstrated that Tgase2 and MMP-9 co-migrated with SBA-labelled proteins. Thus, the micro-fibres are developmentally modulated by enzymes of the ECM in embryonic kidney cortex. These findings illustrate the importance of micro-fibres in directing CD ampulla growth.  相似文献   

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3.
Transglutaminases catalyze the formation of Nε-(γ-glutamyl) isodipeptide crosslinks between proteins. These enzymes are thought to participate in a number of diseases, including neurological disease and cancer. A method associating liquid chromatography and multiple stage mass spectrometry has been developed for the simultaneous quantitation of [Nε-(γ-glutamyl) lysine] isodipeptide and lysine on an ion trap mass spectrometer. Highly specific detection has been achieved in MS3 mode. The method includes a derivatization step consisting of butylation of carboxylic groups and acetylation of amide groups, a liquid-liquid extraction, and a 19-min separation on a 100 × 2.1-mm Beta-basic C18 column with an acetonitrile gradient elution. 13C6-15N2 isotopes of the isodipeptide and the lysine serve as internal standards. The assay was linear in the range of 50 pmol/ml to 75 nmol/ml for the isodipeptide and the range of 10 nmol/ml to 3.5 μmol/ml for the lysine, with correlation coefficients greater than 0.99 for both ions. Intra- and inter-day coefficients of variation ranged from 3.5 to 15.9%. The method was successfully applied to human biological samples known to be crosslinked by transglutaminase such as cornified envelopes of epidermis, fibrin, and normal and Huntington disease brain.  相似文献   

4.
Lathyrus maritimus (L.) Bigel, commonly known as beach pea, grows along the shorelines of Newfoundland, Canada. Rhizobia have been isolated from the subterranean root nodules and the cultures were induced to nodulate seedlings raised in the laboratory. The nodules collected from the field were elongated and sometimes branched with proximal ends thickened. Histological characteristics revealed their indeterminate perennial form. Oleosomes (lipid bodies) were present in the nodule tissues. Morphometric analysis showed their presence in the nodule cortex cells throughout all developmental stages, but they were found in the infected cells only during the early stages of infection and symbiosis. It is suggested that oleosomes are utilized for membrane and rhizobial proliferation during establishment of symbiosis in the infected cells. The role of oleosomes in the cortical cells remains unclear.  相似文献   

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In 1971, first bone bank was established at the Department of Orthopaedic Surgery in Catholic University of Korea. The first clinical case was reported at the Journal of Korean Orthopaedic Association in 1973. Subsequently, more than 60 surgical bone banks were established in the university and teaching hospitals throughout country. In 1990, the Korea Biomaterial Research Institute (KBRI) organised the IAEA/RCA training course on tissue banking. In this course students from 17 countries participated. In 1994 the first collaboration for cadaver tissue recovery was performed. It is important to single out that the various religious groups in Korea have favourable attitudes towards tissue donation, which contributes to the success of the tissue banking programs in the country. The demands of allograft were getting increased in the Korean medical and dental society. Currently, 62 hospital based bone banks, 5 processing tissue banks, 1 regional tissue bank and more than 30 tissue distributors are working in Korea. Based on the U.S.A. usage of more than 1,000,000 grafts per year, 100,000–200,000 grafts will be needed in Korea. Those findings indicate a greatly increased need for training of tissue bank operators. The Korean society will need at least 20–30 tissue bank operators for training in every year. The National Training Centre (NTC) for tissue bank operators and medical personal using the IAEA Curriculum in the Korean languages was established in 2003. From 2004 to 2006, NTC have been trained 40 tissue bank operators. They have produced at least 10,000 tissues per year. These figures indicate a cost saving of US$ 10 million. Within 5 years, NTC will train 100 tissue bank operators. These individuals and their respective banks will provide an increasing number of high quality grafts to the communities they serve at a cost far less than if they were acquired from abroad.  相似文献   

7.
Summary The colloidal gold immunocytochemical technique was used to determine the ultrastructural features of the glandular cells in the pituitaries of male frogs, Rana pipiens, both in vivo and after superfusion in vitro. Specific reactions to antisera against bullfrog gonadotropins, human prolactin, and synthetic 1–39 corticotropin allowed identification of the 3 corresponding types of glandular cells. No immunoreaction was obtained with antisera against human or ovine-growth hormone, human -thyrotropin hormone, and bovine S-100 protein. General morphological features of these immunocytochemically identified glandular cells were similar to those of equivalent cells previously described in other amphibian species. Non-glandular folliculo-stellate cells were distinctive. In freshly removed pituitaries, these folliculo-stellate cells contained lysosome-like structures, but did not show phagocytic vacuoles in the cytoplasm; they contained many mitochondria, and the Golgi complex and endoplasmic reticulum were relatively undeveloped. After 4 or 18 h of superfusion, some immunoreactive gonadotropic, prolactin, and corticotropic cells showed degeneration and destruction. In the same gland, folliculo-stellate cells retained a viable appearance, but showed phagocytic vacuoles containing secretory granule-like structures which were immunoreactive to gonadotropic, prolactin, and corticotropic antibodies. Some folliculo-stellate cells showed phagocytic vacuoles containing complete glandular cells. These results suggest that superfusion causes a destruction of some of the glandular cells, and that folliculo-stellate cells act as phagocytes when cellular debris or moribund cells are present in the intercellular space in the pituitary parenchyma.Supported by grant DCB 8710462 from the National Science Foundation, grant 2148-83 from the CAICYT (Spain) and the Junta de Andalucia (Spain)  相似文献   

8.
The subcellular localization of the ω-hydroxylase of Saccharomycopsis lipolytica was assessed by the analytical fractionation technique, originally described by de Duve C., Pressman, B.C., Gianetto, R., Wattiaux, R. and Appelmans, F., and hitherto little, if at all, applied to yeast. Protoplasts were separated in six fractions by differential centrifugation. Some of these fractions were further fractioned by density gradient centrifugation. The distribution of ω-hydroxylase and 15 other constituents chosen as possible markers of its subcellular membranes has been established. ω-Hydroxylase resulted in being bound to a membrane that containes also cytochrome P-450 and NADPH-cytochrome c reductase. This membrane clearly differs from five other subcellular entities. (1) Mitochondria were characterized by particulate malate dehydrogenase, particulate Antimycin A-insensitive NADH-cytochrome c reductase, oligomycin-sensitive and K+-stimulated ATPase pH 9. (2) Most if not all of the catalase and urate oxidase is peroxisomal. (3) Free ribosomes account for most RNA. (4) Nucleoside diphosphatase is for the first time reported in a yeast and appears to belong to an homogeneous population of small membranes. (5) The soluble compartment contains magnesium pyrophosphatase, alkaline phosphatase, 5′-nucleotidase and part of the NADH-cytochrome c reductase. Latent arylesterase and ATPase pH7 have an unspecific distribution. Alkaline phosphodiesterase I has not been detected.  相似文献   

9.
Abstract

The chemical speciation of zinc- and tin(II)-containing dentrifices and of the reaction between saliva and such toothpastes has been researched using computer simulation. Pivotal formulation variables have been identified (phosphates, fluorides, citrate, etc.) and optimised to suggest formulations having maximum availability, of antimicrobial metal salts Zn2+ (aq) and soluble tin(II) species. Although the concept of having a single dentifrice in which both the zinc and the soluble tin(II) species are maximised together is desirable, it is concluded that at a single pH value, there cannot be maximal availability for both species, but it is possible to achieve levels of antimicrobial metal salts superior to a dentifrice containing either ingredient alone.  相似文献   

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Pathological-length polyglutamine (Q(n)) expansions, such as those that occur in the huntingtin protein (htt) in Huntington's disease (HD), are excellent substrates for tissue transglutaminase in vitro, and transglutaminase activity is increased in post-mortem HD brain. However, direct evidence for the participation of tissue transglutaminase (or other transglutaminases) in HD patients in vivo is scarce. We now report that levels of N(epsilon)-(gamma-L-glutamyl)-L-lysine (GGEL)--a 'marker' isodipeptide produced by the transglutaminase reaction--are elevated in the CSF of HD patients (708 +/- 41 pmol/mL, SEM, n = 36) vs. control CSF (228 +/- 36, n = 27); p < 0.0001. These data support the hypothesis that transglutaminase activity is increased in HD brain in vivo.  相似文献   

12.
Summary Subcellular structures of atrial myoendocrine cells in the rat heart and plasma concentrations of atrial natriuretic peptides (ANP) were examined at six evenlyspaced time points over 24 h, using morphometric techniques and radioimmunoassay.Myofibrils and mitochondria of the cells occupied 73.3% of the cytoplasm; 2% of the cytoplasm was occupied by secretory granules, rough endoplasmic reticulum and Golgi complexes, structures characteristic of endocrine cells. Plasma ANP concentration was maximal at 08.00 h, when the individual volume of secretory granules was minimal. The numerical density of secretory granules was increased at 12.00 h. The plasma ANP concentration was minimal at 20.00 h, when the numerical density was minimal and the individual volume was maximal. The fluctuation in plasma ANP concentrations over 24 h was thus parallel to that in the numerical densities of secretory granules and inverse to that in individual volumes.These results suggest that in rats the secretory activity of atrial myoendocrine cells increases at the beginning of the resting period, whereas it decreases at the beginning of the active phase.  相似文献   

13.
Hoshino A  Isono Y 《Biodegradation》2002,13(2):141-147
Commercial lipases were examined for their degradation efficiency of aliphatic polyester films. In 100 days immersion of polyester films in lipase solutions at37 °C at pH 7.0,Lipase Asahi derived from Chromobacterium viscosum degraded polybutylene succinate-co-adipate (PBSA), poly (-caprolactone) (PCL) and polybutylene succinate (PBS), and Lipase F derived from Rhizopus niveus degraded PBSA and PCL during 4–17 days. Lipase F-AP15 derived fromRhizopus orizae could degrade PBSA in 22 days. In these cases, PBS and PBSA were mainly degraded to dimers, whereas PCL was mainly degraded to monomers. Only poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHB/V) and poly (L-lactide) (PLA) were not degraded in the experiments. However, PLA degraded completely at 55 °C, pH 8.5 with Lipase PL during 20 days. This result could be explained with the sequential reactions of the chemical hydrolysis of the polymer to oligomers at higher pH and temperature, and the succeeding enzymatic hydrolysis of oligomers to the monomers.  相似文献   

14.
The effects of intercropping maize with cowpea, lima bean, soybean, three leguminous cover crops (Tephrosia vogelii Hook F., Canavalia ensiformis L., Sesbania rostrata Bremek. & Oberm.) and cassava on the infestation of Mussidia nigrivenella Ragonot (Lepidoptera: Pyralidae) and other lepidopteran ear borers were studied. Field experiments were conducted in four locations in Benin using a 4x2 pattern of maize-legumes or maize-cassava planting. Intercropping reduced the number of eggs (by >25%) and larvae (by 17.9–53%) of M. nigrivenella compared with the monocrop. Maize-C. ensiformis and maize-T. vogelii proved to be the most effective combinations for reducing M. nigrivenella populations in the different locations. Grain loss and ear damage, which were significantly correlated with the number of insects in the ear, were significantly affected by the intercrops, with losses abated by 47–84% in the four sites. No parasitized larvae were found in any of the locations.  相似文献   

15.
Summary The tentacles of the apodous holothurian Genus Leptosynapta have been studied by use of transmission and scanning electron microscopy. The gross anatomy, water vascular system, fibre systems and ectoneural nerve ring are described. A fuzzy coat of attenuated filaments covers the surface of the tentacle, broken only by secretory ducts. A cuticle underlies the fuzzy coat. Bacteria are common in the subcuticular space. Fixation without osmium gives poor preservation of the surface coats. The epidermis consists of a single layer of columnar cells consisting of Type-1, Type-2, support, goblet and uniciliated cells. Type-1 cells secrete electron-dense material and appear to be homologous to adhesive cells of the tentacles of other holothurians. The support cells contain large, granular vesicles not found in other holothurians. Goblet cells contain flocculent mucus and have an apical cilium. Goblet cells are not found in other holothurian tentacles and may function to lubricate and wrap adhering particles to aid their ingestion. The uniciliated cells are rare, poorly developed and the cilium does not extend past the cuticle. The ultrastructure of the tentacles is discussed in relation to those of other holothurians.  相似文献   

16.
The minor variant of the economically important cyanobacterium, Arthrospira platensis, usually appears in commercial production ponds under solar radiation. However, how sensitive the minor variant to solar UVR and whether its occurrence relates to the solar exposures are not known. We investigated the photochemical efficiency of PSII and growth rate of D-0083 strain and its minor variant in semi-continuous cultures under PAR (400–700 nm) alone, PAR + UV-A (320–400 nm) and PAR + UV-A + UV-B (280–700 nm) of solar radiation. The effective quantum yield of D-0083 at 14:00 p.m. decreased by about 86% under PAR, 87% under PAR + UV-A and 92% under PAR + UV-A + UV-B (280–315 nm), respectively. That of the minor variant was reduced by 93% under PAR and to undetectable values in the presence of UV-A or UV-A + UV-B. Diurnal change of the yield showed constant pattern during long-term (10 days) exposures, high in the early morning and late afternoon but the lowest at noontime in both strains, with the UVR-related inhibition being always higher in the variant than D-0083. During the long-term exposures, cells of D-0083 acclimated faster to solar UV radiation and showed paralleled growth rates among the treatments with or without UVR at the end of the experiment; however, growth of the minor variant was significantly reduced by UV-A and UV-B throughout the period. Comparing to the major strain D-0083, the minor variant was more sensitive to UVR in terms of its growth, quantum yield and acclimation to solar radiation.  相似文献   

17.
Summary The pineal complex of the river lamprey, Lampetra japonica, was examined by means of immunocytochemistry with antisera against serotonin, the precursor of melatonin, and two photoreceptor proteins, rod-opsin (the apoprotein of the photopigment rhodopsin) and S-antigen. Serotonin-immunoreactive cells were observed in both the pineal and the parapineal organ. The proximal portion of the pineal organ (atrium) comprised numerous serotonin-immunoreactive cells displaying spherical somata. In the distal end-vesicle of the pineal organ, the serotonin-immunoreactive elements resembled photoreceptors in their size and shape. These cells projecting into the pineal lumen and toward the basal lamina were especially conspicuous in the ventral portion of the end-vesicle. In addition, single serotonin-immunoreactive nerve cells were found in this location. Retinal photoreceptors were never seen to contain immunoreactive serotonin; amacrine cells were the only retinal elements exhibiting serotonin immunoreaction. Strong S-antigen immunoreactivity was found in numerous photoreceptors located in the pineal end-vesicle. In contrast, the S-antigen immunoreactivity was weak in the spherical cells of the atrium. Thus, the pattern of S-antigen immunoreactivity was roughly opposite to that of serotonin. Similar findings were obtained in the parapineal organ. The rod-opsin immunoreaction was restricted to the outer segments of photoreceptors in the pineal end-vesicle and parapineal organ. No rodopsin immunoreactive outer segments occurred in the proximal portion of the atrium. Double immunostaining was employed to investigate whether immunoreactive opsin and serotonin are colocalized in one and the same cell. This approach revealed that (i) most of the rodopsin-immunoreactive outer segments in the end-vesicle belonged to serotonin-immunonegative photoreceptors; (ii) nearly all serotonin-immunoreactive cells in the end-vesicle bore short rod-opsin-immunoreactive outer segments protruding into the pineal lumen; and (iii) the spherical serotonin-immunoreactive cells in the pineal stalk lacked rod-opsin immunoreaction and an outer segment. These results support the concept that multiple cell lines of the photoreceptor type exist in the pineal complex at an early evolutionary stage.  相似文献   

18.
We have developed an easy and specific enzyme-linked immunoassay (ELISA) for the simultaneous determination of serum metallothinein-1 (MT-1) and 2 (MT-2) in both humans and experimental animals. A competitive ELISA was established using a specific polyclonal antibody against rat MT-2. The antibody used for this ELISA had exhibited the same cross-reactivity with MT in humans and experimental animals. The NH2 terminal peptide of MT containing acetylated methionine was shown to be the epitope of this antibody. The reactivity of this ELISA system with the liver, kidney and brain in MT1/2 knock-out mice was significantly low, but was normal in an MT-3 knock-out mouse. The lowest detection limit of this ELISA was 0.6 ng/ml and the spiked MT-1was fully recovered from the plasma.We investigated the normal range of MT1/2 (25–75%tile) in 200 healthy human serum and found it to be 27–48 ng/ml, and this was compared with the serum levels in various liver diseases. The serum MT1/2 levels in chronic hepatitis C (HCV) patients were significantly lower than healthy controls and also other liver diseases. In the chronic hepatitis cases, the MT1/I2 levels increased gradually, followed by the progression of the disease to liver cirrhosis and hepatocellular carcinoma. In particular, we found significantly elevated MT1/2 plasma levels in Wilson's disease patients, levels which were very similar to those in the Long–Evans Cinnamon (LEC) rat (model animal of Wilson's disease). Furthermore, a significantly elevated MT1/2 level was found in patients with Menkes disease, an inborn error of copper metabolism such as Wilson's disease.  相似文献   

19.
Hyperhomocyst(e)inemia in patients with coronary and peripheral arterial occlusion has been demonstrated by others. Redox-state of homocyst(e)ine causes dysfunction of endothelial cells and promote growth of vascular smooth muscle cells. The role of tissue, protein bound and unbound, oxidative mixed disulfides in the development of fibrous plaque in atherosclerotic lesion is not known. Redox-state around the fibroblasts and vascular smooth muscle cells modulates the expression of extracellular matrix (ECM) components (Tyagi et al. 1996, J Cell Biochem, 61: 139-151). To determine the role of tissue homocystine in fibrotic atherosclerotic plaque development, coronary arteries were isolated from ischemic explanted hearts (n = 10). Apparently normal vascular tissue was obtained from idiopathic cardiomyopathic explanted hearts (n = 10). Tissue extract were prepared from atherosclerotic lesions and from normal arteries devoid of adventitia. Interaction of homocystine with Ellman's reagent (5, 5-dithio-bis-2-nitro benzoic acid) catalyzed by limiting amount of reducing agent (catalyst) generated change in optical density (OD) at 412 nm in dose dependent fashion. We have generated a standard curve between change at 412 nm and amount of homocystine. The change in OD at 412 nm with increasing amount (0-25 g) of homocystine demonstrated linearity. The protein-bound oxidized disulfides were precipitated by trichloroacetic acid (TCA) and free-oxidative disulfides in the supernatant were collected. The pathophysiological amount of protein-bound disulfide in atherosclerotic tissue (1.0 ± 0.2g/mg total protein) was 10 times that in normal tissue (0.1 ±0.01 g/mg, p < 0.001). The amount of free oxidative disulfide in atherosclerotic tissue (1.5 ± 0.3g/mg) was 15 times that in normal tissue (0.12 ± 0.02 g/mg, p < 0.001). To determine the role of homocystine in ECM expression, ECM collagenase activity in the presence and absence of homocystine was measured by zymography. The effect of homocysteine on collagenase activity was biphasic, increased at < [0.01 mM] and inhibited at > [0.1 mM]. To determine whether homocystine regulates vascular tone, isometric measurements were carried out using normal coronary rings. Results suggested that homocystine induced endothelial-modulated vasoconstriction in coronary vessels. Tissue oxidative disulfides and the homocystine may contribute to the development of fibrotic atherosclerotic lesions and vascular dysfunction.  相似文献   

20.
Genetic variability measured by allozymic electrophoresis has been studied in several species of the subterranean rodent genus Ctenomys (Octodontidae). The study was carried out with the main purpose of analysing a special group known as the 'Corrientes group' which inhabits the province of Corrientes in Argentina. The members of the group are, with high probability, isolated reproductively due to their karyotypic differences diploid numbers are between 42 and 70). To evaluate whether the chromosomal differences were the causes of speciation or if they arose a posteriori, we compared the level of the genetic distance among taxa within the orrientes group with all those measured between intraspecific populations in Ctenomys . The results indicate that the distances among the populations of the Corrientes group are at or below the level of those measured among traspecific populations in Ctenomys . Thus, it is unlikely that genetic differentiation triggered speciation. It is shown that this low level of genetic differentiation is not in contradiction with the high levels expected for species originating from one of the possible mechanisms of chromosomal speciation named, chromosomal transilience. Although for geographical reasons it seems obviousthat gene flow is precluded among the members of the Corrientes group, the Slatkin method for estimating Nm values was also used. Because high values of Nm exist but no isolation by distance could be detected, it is suggested that reproductive and geographical isolation are very ecent. Finally, analysis of population variability suggests that the high levels of heterozygosity observed (a) can be explained by the population structure, and (b) are within the range of expected values if bottlenecks have occurred in the recent history of the Corrientes group. As a general conclusion, the results indicate that in the Corrientes group the genetic data support a putative causal role for chromosomes in speciation.  相似文献   

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