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The iridocorneal endothelial (ICE) syndrome is potentially a blinding condition as a result of glaucoma and/or corneal decompensation. The basic pathology seems to be in the corneal endothelium, which many studies confirm takes on a characteristic slit lamp appearance of hammered silver and image reversal with the specular microscope. The origin and morphology of the abnormal cells are unknown. Many histopathological studies of keratoplasty and trabeculectomy specimens reveal as many cell types. This paper reports some general and specular microscopical data from 57 cases of the syndrome, argues that the reason for the variety of histopathological findings in other studies is due to poor sampling of the study material, deduces the morphology of the abnormal cells on specular microscopical criteria, and compares the specular and scanning electron microscopical images in one case with those of other reports. It is tentatively concluded that the appearance of the abnormal cells is a function of their three-dimensional shape and that they produce blister-like vesicles that rupture, collapse, and eventually invaginate.
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PMID:On the morphology of cells of posterior cornea in the iridocorneal endothelial syndrome. 205 30

Myocardial fibrosis can be produced in certain inbred strains of mice after coxsackievirus B subtype 3 (CVB3) infection. The mechanism responsible for this interstitial matrix alteration is unknown. The presumption is that fibrosis occurs in areas of myocyte damage and inflammation associated with viral infection, analogous to scar formation after cell injury in other organ systems. To test this hypothesis, we examined the hearts of A/J strain mice infected with three CVB3 variants (Crowell [CVB3-CR], Woodruff [CVB3-WD], and Lerner [CVB3-LR]), each known to cause different degrees of acute myocardial injury. With these three variants, virus was present in the heart until day 28 after inoculation but was absent thereafter. Fourteen days after inoculation, inflammation with myocyte necrosis was seen in discrete foci throughout the myocardium with all three variants. Collapse and disorganization of the usually delicate connective tissue matrix identifiable by silver impregnation was seen in these areas of myocyte injury. Persistent, diffuse lymphocytic infiltration of the myocardium was seen 55 days after inoculation with CVB3-WD and CVB3-LR, but hearts initially infected with CVB3-CR showed only rare interstitial lymphocytes comparable to uninfected control hearts. The focal scars produced by myocyte necrosis 14 days after inoculation were accentuated and heavily collagenized 55 days after inoculation with CVB3-WD and CVB3-LR; however, these foci were indistinct 55 days after inoculation with CVB3-CR. Furthermore, the usually delicate network of interstitial collagen fibers surrounding individual myocytes became thickened throughout the heart 55 days after inoculation with CVB3-WD and CVB3-LR, away from visibly scarred areas produced early after infection with these variants. This diffuse reticulin thickening was not seen after infection with the Crowell variant. Only the virus variants associated with persistent interstitial inflammation at day 55 developed major collagen matrix alterations and interstitial fibrosis. We conclude that this persistent interstitial lymphocytic infiltration reflects altered immune function related to specific virus variants in this animal strain. We postulate that these lymphocytes are part of a delayed immunopathogenic response uncoupled from the original viral injury and inflammatory damage. Potential mechanisms by which this interstitial lymphocytic infiltration results in fibrosis are discussed.
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PMID:Progressive interstitial collagen deposition in Coxsackievirus B3-induced murine myocarditis. 215 33

The principal structural compartments of the macronucleus of Euplotes eurystomus were examined by ultrastructural and cytochemical procedures. Interphase chromatin is condensed in highly compact granules that stain intensely with the DNA-specific osmium-amine procedure. Nucleoli react strongly with silver and with thiol-specific reagents, but are almost completely unstained by osmium-amine. The organelle of DNA synthesis, the replication band, is composed of 2 zones. The forward zone consists of highly ordered chromatin fibers, stains strongly with osmium-amine, with silver, and with thiol-specific reagents. The rear zone, which is the site of DNA synthesis, is impoverished in DNA, and is very sensitive to collapse induced by in vivo heat shock, or during nuclear isolation.
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PMID:Replication bands and nucleoli in the macronucleus of Euplotes eurystomus: an ultrastructural and cytochemical study. 245 65

The backscattered electron imaging mode of the scanning electron microscope was used to study the ontogenetic acquisition of argyrophilia in Pneumocystis carinii in rats. Silver staining continually increased from the late trophozoite to the mature cyst stage. The silver uptake began with a fine outline at the surface of the bodies of the late trophozoites; their cellular extensions, however, did not stain. The oblate precyst forms acquired the silver in heterogeneous patches. On spherical cysts the silver staining became more uniform and intense with at least one dense spot. The spherical and collapsed cysts also had short silver staining projections that may represent microvilli. Collapsed forms were paler than spherical ones and appear to be cysts that have undergone partial or complete release of sporozoites. These cell surface observations confirm and amplify previous transmission electron microscopical and histochemical studies indicating that silver staining correlates with the acquisition of the cell pellicle.
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PMID:Silver staining of Pneumocystis carinii in the rat's lung. 246 48

We report new spectroscopic properties for a range of silver-metallothionein species. The binding reactions that take place following addition of Ag+ to rabbit liver apoMT 2, and the apo alpha and -beta fragments have been studied using the techniques of circular dichroism (CD) and emission spectroscopy. Titrations carried out at 20 degrees C and 55 degrees C reveal for the first time the formation of a sequence of clusters (Ag6-MT, Ag12-MT and, finally, Ag18-MT) as Ag+ is added to rabbit apoMT 2. (The division of mammalian metallothioneins into two major subforms, MT 1 and MT 2, is based on differences in molecular charge, which results from differences in the sequence of amino acids that do not involve the cysteines.) It is proposed that the novel Ag18-MT complex forms with a structure that involves a well defined three-dimensional structure, in the same manner as that recently reported for the Hg18-MT complex (Cai, W. and Stillman, M. J., (1988) J. Am. Chem. Soc. 110, 7872-7873). Addition of silver in excess of 20 mol equivalents leads to the collapse of this structure. At the elevated temperatures, it is suggested that the protein can exert cooperativity so that completely filled domains are formed rather than mixtures of complexes. This contrasts with the kinetic product in which metals are bound across the peptide chain forming more random "cross-linked" regions in place of the cluster structure. CD spectra were recorded as Ag+ was added to the alpha and beta fragments formed from rabbit liver MT 1. The silver-containing fragments are less stable than the Ag-MT. The alpha and beta fragments exhibit CD spectral patterns indicative of stoichiometrically defined species. The presence of Ag3- alpha MT 1 and Ag6- alpha MT 1 is suggested by the spectral data obtained at 20 and 55 degrees C. Formation of Ag3- beta MT 1 is suggested by the spectral data recorded at 20 degrees C for the beta fragment. We also report that silver-containing metallothioneins are luminescent. Both the position of the band maximum in the 460-600 nm region and the emission intensity are strongly dependent on the stoichiometry of silver to protein. In the range of molar ratios for silver:MT of 1-12, bands at 465 and 520 nm intensify to a maximum for Ag10-MT 2. A band at 575 nm reaches a maximum for Ag16-MT 2. Analysis of the emission data suggests that Ag+ binds in a domain specific mechanism to apoMT 2.
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PMID:Silver binding to rabbit liver metallothionein. Circular dichroism and emission study of silver-thiolate cluster formation with apometallothionein and the alpha and beta fragments. 279 45

In 1984 JR Silver reported on 63 patients who had sustained serious injuries of their cervical spine as a result of games of rugby between the years 1952 and 1982. In this paper his results have been brought up to date. A further 19 players who were treated personally are reported, sustaining their injuries between 1983 and 1987. The mechanism of injury was still blows to the head or the head being driven into the ground. Seven injuries occurred in the scrums all were front row forwards. One was injured when the players charged, two players were inexperienced and the other cases all followed a collapse of the scrum after which the second rows continued to push. Five players were injured while tackling, six players were injured in a ruck and maul situation--in each case they were pushed to the ground while stooping to pick up the ball, other players piled on top of them (one player broke from the scrum and he endeavoured to retrieve a low ball and then fell striking his head). Further research was carried out by circularising all the spinal units in the United Kingdom to obtain the overall figures. It has been found that there has been a reduction in the number of injuries from ten in 1983 to five in 1986/7, presumably from a change in the laws. In order to determine whether a further change in the laws was necessary or whether the existing laws were adequate, research was carried out by video recording several games of rugby and analysing the games later in slow motion and determining how injuries occurred. Most of the injuries in these small number of games occurred in the ruck and maul situation. It was concluded that the majority of such injuries were not due to bad luck but were caused by irresponsible actions. The laws were still being broken and not being enforced. The existing laws were adequate since there has been a reduction in the number of injuries overall, particularly at first class and schoolboy levels, but were not enforced at junior levels-they were the main source of injury.
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PMID:Injuries of the spine sustained during rugby. 338 37

The morphological changes of the inner ear were observed after intravenous administration of 2 g/kg of urea to the guinea pigs with endolymphatic hydrops which had previously been produced by injecting 10% silver nitrate solution into the endolymphatic sac. They showed membranous collapse extensively in the saccule, moderately in the lower turns of the cochlea and less in the upper turns and the utricle. Because of these changes, it is reasonable to assume that urea is causing the endolymph to be reabsorbed in the endolymphatic duct. Furthermore, the effect of urea seemed to depend on the pathological condition of the duct which sometimes showed a varying degree of atrophied change after silver nitrate injection.
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PMID:Effect of urea on endolymphatic hydrops in guinea pigs. 408 Mar 35

Changes in endothelium of the inferior vena cava have been studied in 1, 2, 3, 5, 7, 9, 20, 30 and 50 days on 42 mature rabbits (6 of them used as the control) survived after orthostatic collapse. Fixation in "suza" fluid, after Carnoy or in the 15% formalin solution with a preliminary ultraviolet irradiation in 0.25% silver nitrate solution are used to reveal the cellular borders. Film preparations are prepared and stained with ferric hematoxylin after Heidenhain. The data obtained are statistically treated using the process approximation by means of calculating the sliding averages. The orthostatic collapse, accompanied with certain changes in hemodynamics produces, after the 2d day, a significant decrease in the arrangement of the cellular layer, development of clearly seen certain destructive and necrobiotic shifts in endothelium which are kept for a long time (50 days--time of observations). Beginning from the 5th--7th days, the restorative reaction takes place according to the cell hyperplasia type (increased mitotic coefficient in endotheliocytes) and hypertrophy (increased nuclear and cellular size, presence of binuclear elements), that reflects some processes of the intracellular renewal. The peculiar feature of the regeneration process is its late development and a prolonged course that depends on duration of the pathological shifts in the tissue. The processes observed in the endothelial layer result in an essential increase in the tissue polymorphism that characterizes its main property--plasticity.
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PMID:[Changes in the venous endothelium after acute hemodynamic disorders]. 718 85

Dimethylsulfoxide (DMSO) controlled puff induction and repression (or non-induction) in larval polytene chromosomes of Chironomus tentans were studied for the case of the Balbiani rings (BR). A characteristic reaction pattern, involving BR 1, BR 2, and BR 3, all in salivary gland chromosome IV was found. In vivo exposure of 4th instar larvae (not prepupae) to 10%n DMSO at 18 degrees C first evokes an over-stimulation of BR 3 while DMSO-stimulation of puffing at BR 1 and BR 2 always follows that of BR 3. After removal of the drug, a rapid uniform collapse of all puffs occurs, thus more or less restoring the banding pattern of all previously decondensed chromosome segments. Recovery proceeds as BR's and other puffs reappear. By observing the restoration, one can locate the site from which a BR (puff) originates. BR 2, which is normally the most active non-ribosomal gene locus in untreated larvae, here serves as an example. As the sizes of BR 3, BR 1 and BR 2 change, so do the quantities of the transcriptional products in these gene loci (and vice versa), as estimated electron-microscopically in ultrathin sections and autoradiographically in squash preparations. In autoradiograms, the DMSO-stimulated BRs exhibit the most dense concentration of silver grains and therefore the highest rate of transcriptional activity. In DMSO-repressed BRs (and other puffs) the transcription of the locus specific genes is not completely shut off. In chromosomes from nuclei with high labelling intensities the repressed BRs (and other puffs) always exhibit a low level of 3H-uridine incorporation in vivo. The absence of cytologically visible BR (puff) formation therefore does not necessarily indicate complete transcriptional inactivity. Typically, before the stage of puff formation the 3H-uridine labelling first appears in the interband-like regions.
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PMID:Effects of DMSO on the structure and function of polytene chromosomes of Chironomus. 729 41

We describe experiments on the cryopreservation of the rabbit common carotid artery aimed at improving upon previous results. We describe the design of a double clamp which holds the artery during transportation and storage, preventing twisting, shortening, and collapse of the vessel. The device allowed perfusion with solutions as desired and markedly reduced the extent of endothelial loss during procurement and processing. We also studied the effects of three vehicle solutions; a modified Hanks' solution, a solution originally developed for the cryopreservation of smooth muscle (K-Pipes), and a solution designed for corneal endothelium (CP-Tes). The criteria used to make the assessments were smooth muscle contractility and the structure and function of the vascular endothelium. A new staining method for vascular endothelium (combining propidium iodide with silver nitrate) is described. We found that there was significantly more endothelial cell damage in rabbit carotid arteries frozen in Hanks' solution than in the other solutions, and the recovery of smooth muscle contractility was lowest in the Hanks' group. Arteries cryopreserved using CP-Tes as the vehicle solution showed less endothelial cell damage than arteries preserved with either K-Pipes or Hanks' solution, and these arteries also exhibited the greatest relaxation response to acetylcholine. We conclude that careful handling of the vessels is important; of the solutions studied, CP-Tes is preferred for the cryopreservation of rabbit carotid artery with Me2SO.
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PMID:Cryopreservation of the common carotid artery of the rabbit. 752 24


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