Bioassay Technique and Maintenance of Gyropsylla spegazziniana (Lizer, 1719) (Hemiptera: Psylloidea: Aphalaridae) in vitro Conditions

The secretion of corticotrophin releasing activity (CRA) from the isolated rat hypothalamus incubated in vitro was investigated under various conditions of incubation and of pretreatment of donor animals providing hypothalami. Media from hypothalamic incubations were assayed for CRA by a validated double in-vitro bioassay technique which differentiates CRA from vasopressin. A circadian rhythm was found in the secretion of CRA in vitro from isolated hypothalami obtained from animals killed at different times of the day. Secretion of CRA increased significantly at 19.00 h (dusk) compared with the secretion rate at 07.00 h, in synchrony with a rise in plasma corticosterone levels. In addition, both plasma corticosterone concentrations and CRA secretion in vitro were higher at 07.00 h than at 19.00 h after exposure of the donor animals to a reversed light cycle for 7–10 days. Hypothalami obtained from animals chronically treated with betamethasone in the drinking water showed a diminished secretion of CRA in vitro. Exposure of untreated animals to ether vapour for 2 min immediately before death significantly increased the subsequent secretion of CRA in vitro. Ether exposure did not significantly affect the secretion of CRA in vitro from hypothalami of betamethasone-treated rats. There was a close correlation between plasma corticosterone levels and in-vitro CRA release after these treatments. The results suggest that the secretion of CRA examined in this way is a phenomenon which can reflect the changes which occur in the activity of the hypothalamo-pituitary-adrenal system in vivo during the 24-h cycle, after glucocorticoid treatment and after ether stress.

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Effect of tannins in the fermentation of legume forages using a gas based method

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200021153 ◽

2007 ◽

Vol 2007 ◽

pp. 212-212

Author(s):

P.B. Godoy ◽

I.C.S. Bueno ◽

S.L.S. Cabral Filho ◽

E.F. Nozella ◽

L.A. Castilho ◽

...

Keyword(s):

Nutritive Value ◽

Experimental Conditions ◽

Nutritional Factors ◽

Bioassay Technique

Legume forages are an important source of protein in ruminant feeding but some legumes contain anti-nutritional factors, such as tannins, which can interfere in fermentability. In vitro methods to determine quality of feeds are important to nutritionists. These methods are less expensive, less time consuming and allow more control of experimental conditions than in vivo experiments. The aim of this work was to evaluate the nutritive value of four Brazilian legume forages, with different tannin levels, using the in vitro bioassay technique.

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Tannin bioassay using semi-automated and manual gas production techniques for Brazilian browses

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200013508 ◽

2003 ◽

Vol 2003 ◽

pp. 191-191

Author(s):

S. L. S. Cabral Filho ◽

I. C. S. Bueno ◽

E. F. Nozella ◽

A. L. Abdalla ◽

D. M. S. S. Vitti

Keyword(s):

Polyethylene Glycol ◽

Animal Feed ◽

Rumen Fermentation ◽

Gas Production ◽

Nutritional Factors ◽

Production Techniques ◽

Bioassay Technique ◽

Nutritional Compounds

Native herbaceous browses at Northeast of Brazil have a dry tolerance and have been used as animal feed. Some of those plants have anti nutritional compounds such as tannins that can interfere on their intake and digestibility. Polyethylene glycol (PEG) has been used in gas-based techniques for assessing anti nutritional factors in tanniniferous plants for ruminants. The objective of this work was to compare the tannin bioassay technique using the semi-automated (Reading Pressure Technique - RPT) and manual (syringe) gas production techniques to evaluate the tannin effect upon in vitro rumen fermentation, using PEG as an inhibitor of tannin effects.

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A NEW BIOASSAY TECHNIQUE FOR THE MEASUREMENT IN VITRO OF THYROTROPHIC HORMONE IN SERUM AND IN PITUITARY EXTRACTS

Journal of Endocrinology ◽

10.1677/joe.0.0250259 ◽

1962 ◽

Vol 25 (2) ◽

pp. 259-269 ◽

Cited By ~ 20

Author(s):

K. E. KIRKHAM

Keyword(s):

Thyroid Tissue ◽

Mean Value ◽

Assay Method ◽

Human Pituitary ◽

Thyrotrophic Hormone ◽

Bioassay Technique ◽

The Mean ◽

A New Technique ◽

New Bioassay

SUMMARY A new technique by which thyrotrophic hormone (TSH) can be rapidly measured in vitro in the serum of euthyroid subjects and in human pituitary extracts is presented. In euthyroid male subjects levels of TSH in serum ranged from 0 to 30·1 i.u. × 10−3/100ml., the mean value being 10·8. In normal menstruating women the mean value was 4·8 and the range 0 to 21·5 i.u. × 10−3/100 ml. In human pituitary extracts, TSH could be detected in all fractions tested, but the amount of activity present was greatest in the gonadotrophin fraction. When the latter was separated into the FSH and LH components the TSH activity was found to be mainly associated with the LH fraction. The specificity of the method has been examined by incubating thyroid tissue with other hormones of pituitary origin and measuring their effect on the response to TSH. It is concluded that any interference with the assay method produced by FSH and LH is due to their contamination with TSH.

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Ultrastructural Investigations of the Contractile Filaments of Amoebae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050950 ◽

1974 ◽

Vol 32 ◽

pp. 188-189

Author(s):

P.L. Moore

Keyword(s):

Cytoplasmic Streaming ◽

Three Dimensional ◽

Freeze Fracture ◽

Amoeboid Movement ◽

Different Types ◽

Chemical Conditions ◽

Complete Interpretation

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.

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In Vitro Induction of Crystals of MT Protein by Vinblastine-Colcemid in Mouse Spermatids

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050676 ◽

1974 ◽

Vol 32 ◽

pp. 132-133

Author(s):

John J. Wolosewick ◽

John H. D. Bryan

Keyword(s):

Endoplasmic Reticulum ◽

Smooth Endoplasmic Reticulum ◽

Nuclear Ring ◽

Rough Er ◽

Distal Direction ◽

In Vitro Induction

Early in spermiogenesis the manchette is rapidly assembled in a distal direction from the nuclear-ring-densities. The association of vesicles of smooth endoplasmic reticulum (SER) and the manchette microtubules (MTS) has been reported. In the mouse, osmophilic densities at the distal ends of the manchette are the organizing centers (MTOCS), and are associated with the SER. Rapid MT assembly and the lack of rough ER suggests that there is an existing pool of MT protein. Colcemid potentiates the reaction of vinblastine with tubulin and was used in this investigation to detect this protein.

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Induction and Differentiation of Dental Epithelium in Vivo and in Vitro

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053425 ◽

1982 ◽

Vol 40 ◽

pp. 142-145

Author(s):

E. J. Kollar

Keyword(s):

Connective Tissue ◽

Oral Mucosa ◽

Basal Lamina ◽

Functional Derivatives ◽

Specific Source ◽

Dental Epithelium ◽

Connective Tissue Stroma

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.

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Immunoenzymatic demonstration of the simultaneous presence of transferrin, hemopexin and albumin in a same hepatocyte and their ultrastructural localization

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081309 ◽

1978 ◽

Vol 36 (2) ◽

pp. 88-89

Author(s):

M. Kraemer ◽

J. Foucrier ◽

J. Vassy ◽

M.T. Chalumeau

Keyword(s):

Plasma Proteins ◽

Rat Hepatocytes ◽

Ultrastructural Localization ◽

Carrier Proteins ◽

Normal Cells ◽

Adult Rat ◽

Adult Rat Hepatocytes ◽

Monospecific Antisera ◽

Different Levels

Some authors using immunofluorescent techniques had already suggested that some hepatocytes are able to synthetize several plasma proteins. In vitro studies on normal cells or on cells issued of murine hepatomas raise the same conclusion. These works could be indications of an hepatocyte functionnal non-specialization, meanwhile the authors never give direct topographic proofs suitable with this hypothesis.The use of immunoenzymatic techniques after obtention of monospecific antisera had seemed to us useful to bring forward a better knowledge of this problem. We have studied three carrier proteins (transferrin = Tf, hemopexin = Hx, albumin = Alb) operating at different levels in iron metabolism by demonstrating and localizing the adult rat hepatocytes involved in their synthesis.Immunological, histological and ultrastructural methods have been described in a previous work.

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Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100055448 ◽

1982 ◽

Vol 40 ◽

pp. 520-521

Author(s):

Ann Chidester Van Orden ◽

John L. Chidester ◽

Anna C. Fraker ◽

Pei Sung

Keyword(s):

Electron Microscopy ◽

Corrosion Behavior ◽

Anodic Polarization ◽

Saline Solution ◽

Saturated Calomel Electrode ◽

Physiological Saline ◽

X Ray ◽

Physiological Saline Solution ◽

Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

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Ultrastructural Correlations between Clonal Human Tumor Colonies and in Vivo Neoplasms

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053711 ◽

1982 ◽

Vol 40 ◽

pp. 210-211

Author(s):

M.J. Murphy ◽

R.R. Price ◽

J.C. Sloman

Keyword(s):

Cultured Cells ◽

Human Tumor ◽

Cell Type ◽

Tumor Mass ◽

Initial Cell ◽

Cloning Assay ◽

Human Tumor Cloning ◽

The Relationship

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.

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