The Relationship of Thyroid Activity to Lactation, Growth, and Sex in Sheep1

1956 ◽  
Vol 15 (3) ◽  
pp. 625-630 ◽  
Author(s):  
O. N. Singh ◽  
H. A. Henneman ◽  
E. P. Reineke
Keyword(s):  
Thyroid Activity ◽  
Relationship Of ◽  
The Relationship

ON THE RELATIONSHIP OF CATECHOLAMINES AND THYROID ACTIVITY TO VENTRICULAR FIBRILLATION DURING HYPOTHERMIA IN DOGS

1963 ◽  
Vol 41 (2) ◽  
pp. 361-367 ◽  
Author(s):  
D. R. Varma ◽  
R. A. Gillis ◽  
K. I. Melville
Keyword(s):  
Ventricular Fibrillation ◽  
Coronary Occlusion ◽  
Protective Action ◽  
Protective Effects ◽  
Thyroid Activity ◽  
Endogenous Catecholamines ◽  
Combined Pretreatment ◽  
Antithyroid Treatment ◽  
Relationship Of ◽  
The Relationship

The possible significance of endogenous catecholamines in the production of hypothermic ventricular fibrillation has been investigated.It is shown that in dogs under pentobarbitone anesthesia, neither iproniazid nor phenoxybenzamine pretreatment reduces the incidence of ventricular fibrillation following coronary occlusion during hypothermia. Reserpine pretreatment markedly reduced both the catecholamines content of the left ventricle and the incidence of ventricular fibrillation. This protective action of reserpine can be counteracted by combined pretreatment with liothyronine sodium, although the catecholamines of the heart remained at a low level. Conversely, thyroidectomy and methimazole treatment also greatly reduced the incidence of ventricular fibrillation without significantly reducing cardiac catecholamines. These experiments reveal no correlation between the ventricular catecholamines content and the incidence of ventricular fibrillation. It is suggested that the protective effects of reserpine and thyroidectomy or antithyroid treatment might be due to depression of tissue metabolism.

ON THE RELATIONSHIP OF CATECHOLAMINES AND THYROID ACTIVITY TO VENTRICULAR FIBRILLATION DURING HYPOTHERMIA IN DOGS

1963 ◽  
Vol 41 (1) ◽  
pp. 361-367 ◽  
Author(s):  
D. R. Varma ◽  
R. A. Gillis ◽  
K. I. Melville
Keyword(s):  
Ventricular Fibrillation ◽  
Coronary Occlusion ◽  
Protective Action ◽  
Protective Effects ◽  
Thyroid Activity ◽  
Endogenous Catecholamines ◽  
Combined Pretreatment ◽  
Antithyroid Treatment ◽  
Relationship Of ◽  
The Relationship

The possible significance of endogenous catecholamines in the production of hypothermic ventricular fibrillation has been investigated.It is shown that in dogs under pentobarbitone anesthesia, neither iproniazid nor phenoxybenzamine pretreatment reduces the incidence of ventricular fibrillation following coronary occlusion during hypothermia. Reserpine pretreatment markedly reduced both the catecholamines content of the left ventricle and the incidence of ventricular fibrillation. This protective action of reserpine can be counteracted by combined pretreatment with liothyronine sodium, although the catecholamines of the heart remained at a low level. Conversely, thyroidectomy and methimazole treatment also greatly reduced the incidence of ventricular fibrillation without significantly reducing cardiac catecholamines. These experiments reveal no correlation between the ventricular catecholamines content and the incidence of ventricular fibrillation. It is suggested that the protective effects of reserpine and thyroidectomy or antithyroid treatment might be due to depression of tissue metabolism.

THE RELATIONSHIP OF ALTERED THYROID ACTIVITY TO VARIOUS REPRODUCTIVE PHENOMENA IN GILTS

1958 ◽  
Vol 17 (1) ◽  
pp. 54-62 ◽  
Author(s):  
J. J. LUCAS ◽  
G. E. BRUNSTAD ◽  
S. H. FOWLER
Keyword(s):  
Fertilization Rate ◽  
Embryonic Mortality ◽  
Thyroid Activity ◽  
Fertilization Rates ◽  
The Third ◽  
Altered Thyroid ◽  
Relationship Of ◽  
The Relationship ◽  
Basal Ration ◽  
Duration Of Gestation

SUMMARY Three groups of fifteen Palouse gilts each were used to test the effects of altered thyroid activity on ovulation and fertilization rates and embryonic mortality in swine. Two groups received 0·15% thiouracil and 0·0123% thyroprotein, respectively, in a basal ration, and the third served as controls. All gilts were assigned to treatment sets at first oestrus and were bred to fertile boars at second oestrus. One-third of the gilts in each group were slaughtered 12–24 hr after the end of second oestrus, one-third slaughtered 25 days post coitum and the remainder allowed to farrow. An analysis of variance revealed no significant differences between groups for: ovulation rate, fertilization rate, embryonic mortality during the first 25 days of gestation, number of normal embryos at 25 days post coitum, or number of pigs born alive. A significant increase in the duration of gestation was found for thiouracil-treated females. Pigs born to thyroproteinsupplemented mothers were significantly heavier at birth than pigs born to thiouracil-treated mothers. Under the conditions of this experiment, X2 analysis indicated that thiouracil produced a highly significant embryonic mortality during gestation from the 25th day of pregnancy until farrowing. Thyroprotein treatment tended to lower embryonic mortality during the same period.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

The relationship of IGE receptor topography to signaling activity in RBL-2H3 mast cells

1991 ◽  
Vol 49 ◽  
pp. 236-237
Author(s):  
J.R. Pfeiffer ◽  
J.C. Seagrave ◽  
C. Wofsy ◽  
J.M. Oliver
Keyword(s):  
Mast Cells ◽  
Protein A ◽  
Scattered Electron ◽  
Ige Receptor ◽  
Receptor Complexes ◽  
Ige Binding ◽  
Electron Imaging ◽  
Small Clusters ◽  
Relationship Of ◽  
The Relationship

In RBL-2H3 rat leukemic mast cells, crosslinking IgE-receptor complexes with anti-IgE antibody leads to degranulation. Receptor crosslinking also stimulates the redistribution of receptors on the cell surface, a process that can be observed by labeling the anti-IgE with 15 nm protein A-gold particles as described in Stump et al. (1989), followed by back-scattered electron imaging (BEI) in the scanning electron microscope. We report that anti-IgE binding stimulates the redistribution of IgE-receptor complexes at 37“C from a dispersed topography (singlets and doublets; S/D) to distributions dominated sequentially by short chains, small clusters and large aggregates of crosslinked receptors. These patterns can be observed (Figure 1), quantified (Figure 2) and analyzed statistically. Cells incubated with 1 μg/ml anti-IgE, a concentration that stimulates maximum net secretion, redistribute receptors as far as chains and small clusters during a 15 min incubation period. At 3 and 10 μg/ml anti-IgE, net secretion is reduced and the majority of receptors redistribute rapidly into clusters and large aggregates.

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