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Articles 31 - 41 of 41

Full-Text Articles in Cell Anatomy

The Timing And Pattern Of Myogenesis In Hymenochirus Boettgeri, Matthew T. Smetanick, Rafael O. De Sá Jun 1999

The Timing And Pattern Of Myogenesis In Hymenochirus Boettgeri, Matthew T. Smetanick, Rafael O. De Sá

Biology Faculty Publications

Differences in the relative timing of homologous developmental events among closely related species, known as heterochronies, may provide valuable clues in understanding evolutionary relationships (McKinney, 1988; McNamara, 1995). Examining the timing of myogenic events is a relatively easy and effective method for finding heterochronic events. For example, whether muscle proteins and myofibrils appear before or after multinucleation can be determined through histological techniques (Kielbowna, 1981). Simple observations of live specimens can pinpoint functional landmarks such as first twitch (spontaneous or due to external stimuli) and first heartbeat.

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The Role Of Retinoids And Protein Kinase C In Vascular Smooth Muscle Cell Proliferation And Function, Shaoshan Wang Jan 1999

The Role Of Retinoids And Protein Kinase C In Vascular Smooth Muscle Cell Proliferation And Function, Shaoshan Wang

Theses, Dissertations and Capstones

The structural and functional changes in the arterial wall of humans and animals accompany the development of hypertension and atherosclerosis. Hence, great interest exists in the mechanisms that govern vascular smooth muscle cell contraction and proliferation. Rat aortic rings maintained in organ culture show a significant loss of contractility; whereas, vascular smooth muscle cells in culture quickly dedifferentiate into a secretory phenotype with a marked capacity for proliferation. The addition of all-trans retinoic acid (RA) and retinol to the plasma-containing medium preserved the contractile response of cultured vessels. Removal of endothelium prior to culture abolished these effects. All-trans retinoic acid …

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The Biology Of Xenopus By R. C. Tinsley And H. C. Kobel, Rafael O. De Sá May 1998

The Biology Of Xenopus By R. C. Tinsley And H. C. Kobel, Rafael O. De Sá

Biology Faculty Publications

The Biology of Xenopus presents a summary of current knowledge about a single genus resulting from a symposium held at the Zoological Society of London in September 1992. This approach to summarizing available information has also been taken for other taxa, such as Atelopus (Lotters, 1996). However, the task of compiling data for Xenopus is enormous relative to any other amphibian group, because Xenopus laevis has become a model system for molecular and development research (Cannatella and de Sa, 1993). Unfortunately, most of our knowledge of Xenopus is biased toward this single species. There are about 20 recognized species of …

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Molecular Mapping Of The Fatty (F) (Formerly Corpulent) Gene In The La/N Rat Obesity Model, Kenneth G. Butz Jan 1998

Molecular Mapping Of The Fatty (F) (Formerly Corpulent) Gene In The La/N Rat Obesity Model, Kenneth G. Butz

Theses, Dissertations and Capstones

The LA/N-corpulent (cp) rat obesity model was a congenic rat strain developed at the National Institutes of Health by C. T. Hansen . The LA/N-cp rat originated from breeding the Koletsky rat, possessing the corpulent gene, with the normotensive LA/N inbred rat. The autosomal recessive single gene mutation, cp, produces obesity with hyperphagia, hyperinsulinemia and elevated activities of liver and skeletal muscle lipogenic enzymes in the LA/N-cp rat model. The Zucker-fatty mutation, which was mapped to rat chromosome , resulted in a comparable, but not identical obesity syndrome. Breeding experiments by Yen et al …

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Chondrocranial Morphology Of Leptodactylus Larvae (Leptodactylidae: Leptodactylinae): Its Utility In Phylogenetic Reconstruction, Peter M. Larson, Rafael O. De Sá Jan 1998

Chondrocranial Morphology Of Leptodactylus Larvae (Leptodactylidae: Leptodactylinae): Its Utility In Phylogenetic Reconstruction, Peter M. Larson, Rafael O. De Sá

Biology Faculty Publications

Chondrocranial morphology of leptodactylid frogs is scarcely known and has not been completely described for any species of Leptodactylus. We describe the diversity of chondrocranial morphology in the genus Leptodactylus based on the analysis of 22 species, representing the four species groups: the fuscus Group, ocellatus Group, melanonotus Group, and pentadactylus Group. Furthermore, 26 characters are identified and used in a phylogenetic analysis. The phylogenetic analysis using Physalaemus, Crossodactylus, and Hylodes as outgroups suggests two monophyletic clades within Leptodactylus: the melanonotus-ocellatus clade and the pentadactylusfuscus clade. However, it does not support the monophyly of the species groups as currently recognized …

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Use Of The (3)H-Tetracycline Rat Model In The Study Of Skeletal Compartmentalization And Metabolism Of Calcium In The Maturing Male And Female Rat And The Role Of The Skeleton In Calcium Homeostasis In The Adolescent Male Rat, Darrin Lee Demoss Jan 1996

Use Of The (3)H-Tetracycline Rat Model In The Study Of Skeletal Compartmentalization And Metabolism Of Calcium In The Maturing Male And Female Rat And The Role Of The Skeleton In Calcium Homeostasis In The Adolescent Male Rat, Darrin Lee Demoss

Theses, Dissertations and Capstones

The (3)H-tetracycline bone labeling procedure was employed to monitor bone resorption from urinary loss curves in male and female rats of various ages. In addition, whole body dry skeletal mass and the loss of (3)H-tetracycline from individual bones was determined. It was found that the dry skeletal mass/body mass ratio of 24-week-old females was 30-40% greater than that for males. The urinary loss of (3)H-tetracycline was described by a double exponential equation indicating the presence of two distinct and independent exchangeable bone compartments. Both compartments decrease in size with age, but their label loss activities were different. The label loss …

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Xenopus Laevis As A Model Organism, David C. Cannatella, Rafael O. De Sá Dec 1993

Xenopus Laevis As A Model Organism, David C. Cannatella, Rafael O. De Sá

Biology Faculty Publications

Model organisms are often assumed to be representative of some more inclusive taxon of which the species is a part. This assumption leads to mistaken generalizations about the evolutionary and comparative significance of the data gathered. This paper reviews com? parative and evolutionary studies of Xenopus laevis and its relatives. Phylogenetic analysis of data from DNA sequences and morphology indicate that Xenopus is monophyletic and that Silurana is its sister group. The most basal lineages of Pipidae diverged prior to the breakup of Gondwana. The bizarre morphology of Xenopus is in part due to changes in the mode of meta? …

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Phase I Trial Of The Murine Monoclonal Anti-Gd2 Antibody 14g2a In Metastatic Melanoma, Mansoor Saleh, M B. Khazaeli, Richard Wheeler, Edward Dropcho, Tiepu Liu, Marshall Urist, Donald Miller, Sharon Lawson, Pam Dixon, Charles Russell Jan 1992

Phase I Trial Of The Murine Monoclonal Anti-Gd2 Antibody 14g2a In Metastatic Melanoma, Mansoor Saleh, M B. Khazaeli, Richard Wheeler, Edward Dropcho, Tiepu Liu, Marshall Urist, Donald Miller, Sharon Lawson, Pam Dixon, Charles Russell

Haematology and Oncology, East Africa

In a phase I trial, 12 patients with GD2 antigen-positive metastatic melanoma received the murine anti-GD2 monoclonal antibody 14G2a. The monoclonal antibody was administered in four doses over an 8-day period with total dose ranging from 10 to 120 mg. All patients receiving >10 mg of 14G2a experienced transient abdominal/pelvic pain during the antibody infusion. Five patients had a delayed extremity pain syndrome following the third and fourth antibody infusion. Four of the five patients developed neurological toxicity, including two patients with significant although reversible motor neuropathy. Two of the patients developed hyponatremia secondary to a syndrome of …

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The Chromosomes Of The Yeast Cell, Donald William Penn Feb 1949

The Chromosomes Of The Yeast Cell, Donald William Penn

Bachelors’ Theses

Saccharomyces cerevisiae has long been a fungus of economic importance in the baking and beverage fields. A large amount of research has been done on this yeast cytologically and biochemically. However, due to its small size and difficulty in staining, the cytology of the yeast cell remains somewhat in question. Chromosomes and division figures have been demonstrated by several workers, but there still remain sharp differences of opinion as to the nature of the nucleus. Recent work on the genetics of yeast has shown evidence of chromosome division similar to that occurring in higher plants and studies of linkage have …

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The Mammalian Erythrocyte, H.J. Werner Jun 1939

The Mammalian Erythrocyte, H.J. Werner

Bachelors’ Theses

An investigation of bibliographies shows that the red corpuscles of the blood have been studied very extensively, in fact, wore so than any cell in the mammalian body. The study has progressed vigorously and from varied points of view.

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Organization And Polarity Of Protoplasm, John P. Munson Jan 1910

Organization And Polarity Of Protoplasm, John P. Munson

All Faculty Scholarship for the College of the Sciences

In higher forms of life, we usually concede the presence of an organ specialized for the performance of a function. In these higher forms coordination of organs, which entails a regular sequence in their functions, is readily made out; and it seems a mere platitude to say, of these, that organization determines the functions of the organism. To what extent can functions exist in the absence of organization; does the one precede the other; or have function and organization developed simultaneously, out of matter devoid of both structure and function? In my studies on the cell, I have kept these …

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