Evaluation of local injection of Acrylic Denture Base Material in Bucks spermatic cord.

This study was performed to identify gross and histopathology changes which can be occur in testis and spermatic cord following injection of Acrylic Dental Base Material inside spermatic cord , the agent is widely present ,cheep, quick ,highly solid and used as a substance of chemical castration. It was injected inside spermatic cord of 15 healthy adult bucks in the ratio of 3:1 bilaterally ; Treated animals where divided randomly in to 5 groups depending on time for gross and histopathology examination after injected with the material. Animals were followed up for 7 days, 14 days, 30 days, 60 days, and 150 days after injection. Result showed good and immediate hardening after 20-25 min. of injected material. Gross examination of testis after 7-14 days of material injection didn’t showed marked changes. While after 30 -60 days showed thickening of tunica vaginals which was easy isolated, and the testis was atrophied .And after 150 days showed disappear of testis structures with more atrophied. Histopathology changes of testis characterized by reduce rate of spermatogenesis , thickening of basement membrane ,inflammation was reduce in late stage and deposition of fibrous tissue . While the mean feature of histopathology changes of spermatic cord include, infiltration of inflammatory cells, then fibrosis which lead to complete contraction and obstruction of it from first week after injection

Three-dimensional visualization of coated vesicle formation in fibroblasts.

Fibroblasts apparently ingest low density lipoproteins (LDL) by a selective mechanism of receptor-mediated endocytosis involving the formation of coated vesicles from the plasma membrane. However, it is not known exactly how coated vesicles collect LDL receptors and pinch off from the plasma membrane. In this report, the quick-freeze, deep-etch, rotary-replication method has been applied to fibroblasts; it displays with unusual clarity the coats that appear under the plasma membrane at the start of receptor-mediated endocytosis. These coats appear to be polygonal networks of 7-nm strands or struts arranged into 30-nm polygons, most of which are hexagons but some of which are 5- and 7-sided rings. The proportion of pentagons in each network increases as the coated area of the plasma membrane puckers up from its planar configuration (where the network is mostly hexagons) to its most sharply curved condition as a pinched-off coated vesicle. Coats around the smallest vesicles (which are icosahedrons of hexagons and pentagons) appear only slightly different from "empty coats" purified from homogenized brain, which are less symmetrical baskets containing more pentagons than hexagons. A search for structural intermediates in this coat transformation allows a test of T. Kanaseki and K. Kadota's (1969. J. Cell Biol. 42:202--220.) original idea that an internal rearrangement in this basketwork from hexagons to pentagons could "power" coated vesicle formation. The most noteworthy variations in the typical hexagonal honeycomb are focal juxtapositions of 5- and 7-sided polygons at points of partial contraction and curvature in the basketwork. These appear to precede complete contraction into individual pentagons completely surrounded by hexagons, which is the pattern that characterizes the final spherical baskets around coated vesicles.

Myocardial energetics during isometric twitch contractions of cat papillary muscle

During myocardial tetanus, when activation is maximum and constant, there is a linear relationship throughout contraction between oxygen consumption (MVo2) and the cumulative product of active tension and time (integral of AT). The goal of this study was to determine the relation of MVo2 to integral of AT during isometric myocardial twitch contractions. Ten right ventricular cat papillary muscles were studied in a flow respirometer. MVo2 was determined during contractions unloaded from Lmax to a slack length at successive 100-ms intervals after stimulation. In contrast to the linear relationship observed during tetanus, MVo2/integral of AT varied during twitch contractions: when the muscles were made slack 100 ms after stimulation MVo2/integral of AT was 389 +/- 51 (SE) (nl of O2/mg of dry muscle)/(N of active tension/mm2.s of active tension). This value was 94 +/- 7 at peak active tension and was constant thereafter. There was a continuous increase in cumulative MVo2 as integral of AT increased; before integral of AT began, MVo2 was 0.41 +/- 0.04 (nl of O2/mg)/contraction at Lmax and 0.22 +/- 0.04 at a slack length; at peak isometric tension MVo2 was 1.84 +/- 0.19; for a complete contraction MVo2 was 2.89 +/- 0.25. These data support two concepts 1) activation energy is small and dependent on initial length and tension; and 2) integral of AT is variably energy dependent throughout the entire isometric twitch contraction.

On Chromatic Effector Speed in Xenopus and Anguilla and the Level of Melanophore Expanding Hormone in Eel Blood

1. The chromatic effector speed of the two species has been measured by perfusing fully dark animals with saline until they were fully pale and then introducing B hormone into the perfusate to observe the reverse change. It was found that: (a) Complete expansion of the melanophores of Xenopus takes 100 min. Complete contraction of the melanophores of Xenopus takes 70 min. (b) Complete expansion of the melanophores of the eel takes 30 min. Complete contraction of the melanophores of the eel takes 20 min. Adrenalin exercises a potent contracting effect on the melanophores of the eel even in the presence of excess B. It has no direct effect on the melanophores of Xenopus. 2. Increased concentration of B hormone in the perfusate above the threshold dose does not increase the speed of melanophore expansion in either animal. This implies something approaching an all or nothing reaction on the part of the melanophore itself. The usual interpretation of the "all or nothing" behaviour of effectors is that it is in large measure due to the well-known "all or nothing" action of their efferent nerves. 3. Using eels of approximately the same weight estimations of: (a) concentration of B hormone in the circulation of a dark fish, (b) concentration of B hormone in the pituitary of a dark fish, (c) total blood volume, indicate that the distribution of B between pituitary and circulation in a dark animal is of the order pituitary 1, circulation 10. 4. Caustic soda treated extracts of posterior lobe pituitary which evoke the same rise of melanophore index as untreated extracts do not maintain the expanded condition of the melanophores for the same period. The factors involved are discussed.

The Nerve Net of the Actinozoa

1. The relation of the "staircase" effects in the vertebrate heart, in the bell of Medusae and in the sphincter of Calliactis is discussed. Whereas in the heart the effect is due to an intrinsic increase of contractility of the whole contractile tissue, evidence is brought to show that the staircase in Calliactis and in Medusae depends upon neuromuscular facilitation by which each stimulus in a series reaches more and more individual muscle fibres. 2. The relation of different types of contraction in coelenterate muscle is discussed. It is shown how this depends upon the relation of the stimulation interval necessary for a facilitated response and the duration of a complete contraction and relaxation of the muscle. If these are about equal the step-like contraction of the sphincter of Calliactis results; if the facilitation interval is long a staircase similar to that of a Medusa bell is produced; if the duration of the twitch is relatively long a smooth contraction as in the mesenteric muscle of Calliactis is produced.