Biochemistry, Biophysics, and Structural Biology Commons^™

Mathematical Model Of Placental Oxygen And Carbon Dioxide Exchange, Ester P. Hill

Loma Linda University Electronic Theses, Dissertations & Projects

This model of placental CO₂ and O₂ exchange calculates the time course of changes in P_^CO2, [HCO₃^-], and [H⁺] in each of four "compartments" of placental exchange vessels: maternal erythrocytes, maternal plasma, fetal plasma and fetal erythrocytes. The changes in hemoglobin-bound CO₂ (carbamate) and oxyhemoglobin contents within the erythrocytes are also calculated, permitting consideration of the Haldane and Bohr effects. Equations were written to represent one-dimensional steady state CO₂ and O₂ diffusion between concurrent maternal and fetal capillaries and the subsequent hydration, carbamino and oxyhemoglobin reactions. The equations …

The Nature Of Salmonella Phage P3 Modification And Restriction By Growth In Escherichia Coli, Clark A. Pearson

Loma Linda University Electronic Theses, Dissertations & Projects

The Salmonella potsdam group B bacteriophage P3, which grows in the rough variant strain of S. potsdam (SP2-R) and E. coli K_CS11, K_W117, and C⁺/L with similar efficiencies, was restricted by SP2-R after a passage though E. coli. The entrance of restricted E. coli-grown phage DNA into nonpermissive SP2-R cells was confirmed by the finding that after adsorption of restricted ³²P-labeled P3-C₁·C⁺/L to SP2-R and removal of the adsorbed phage heads from cells, 80.3% of the labeled DNA activity sedimented with the cells. Thus restricted P3 DNA …

The Transfer Of Hydrogen In The Reduction Of Progesterone, William H. Kersey

Loma Linda University Electronic Theses, Dissertations & Projects

Experimental female rats were given daily injections of synthetic estrogens for six months. The effect on rat ovarian 20α-OH-SDH was not definitive. Diethylstilbestrol and 17α-ethynylestradiol caused a significant drop in activity as compared with controls while mestranol caused a slight increase in activity. A synthetic progestin, medroxyprogesterone, had no apparent effect on the activity of the enzyme.

Rat ovarian 20α-OH-SDH was purified fivefold by ammonium sulfate fractionation and chromatography on DEAE-cellulose.

The homogeneity of the enzyme was checked by means of disc gel electrophoresis. At pH 8.2 no significant contamination appeared in the electrophoretic pattern, but at pH 9.0 five …

Isolation And Partial Characterization Of The Toxic Substance From Eremocarpus Setigerus Benth, Shuliang Lee

Loma Linda University Electronic Theses, Dissertations & Projects

The work on the active substance of Eremocarpus setigerus Benth has been previously performed by Naito and Noller. However, the investigation was not complete. Therefore we isolated and tested this substance by steam distillation and thin layer chromatography technique. A yellow sticky toxic substance was isolated with Rf values of 0.15 in benzene system and 0.57 in benzene-absolute ethanol (95:5 v/v) system.

The toxic substance which is free of halogen, nitrogen, and sulfur, is soluble in ethyl ether, ethanol, and concentrated sulfuric acid. It has a maximum absorption in the ultraviolet region that indicates the presence of unsaturation. Its infrared …

An Organ Culture Technique For Maintaining The Pulp Tissue Of Intact Human Teeth, John P. Devincenzo

Loma Linda University Electronic Theses, Dissertations & Projects

The size of explants in organ culture is limited by their ability to feed, respire, and excrete by diffusion. The perfusion procedure described in this report is not limited to a particular explant size. The test tissue was the adult human tooth.

In order to maintain the pulp tissue of the intact human tooth in organ culture, special precautions were taken to prevent internal necrosis and to allow diffusion of nutrients and waste products. Using aseptic technique, a standard tissue culture medium plus appropriate antibiotics were delivered to a glass manifold housed in an incubator with an atmosphere at 100% …

A Comparative Study Of The Growth Of Polyoma Virus In Two Secondary Cell Lines: Mouse Lymphoma And Normal Mouse Fibroblasts, Rheeta M. Stecker

Loma Linda University Electronic Theses, Dissertations & Projects

In comparing the growth of polyoma virus in secondary cell cultures of a mouse lymphoma (P388D₁, a known polyoma-supporting strain) and normal mouse fibroblasts (Earle’s L cells), the following observations have been made.

The L cell is capable of supporting the growth of the polyoma virus with reproduction and release of infectious particles. Viruses appear in the fluid from time to time over a period of several weeks. This probably represents a carrier state of the virus in L cells. Many of the L cells in infected cultures are not killed by the virus infection.

Virus particles released …

Biochemical Changes In The Devascularized Femoral Head, Jeanne Wiesseman

Loma Linda University Electronic Theses, Dissertations & Projects

A review of the literature indicates that there have been many attempts to determine the viability of the femoral head after trans cervical fracture of the neck of the femur. These methods have included the use of radioactive isotopes, venography, arteriography and intramedullary pressure determinations. None of these methods have proved entirely satisfactory.

The purpose of this investigation was to determine some of the biochemical changes taking place in the devascularized femoral head. Nineteen dogs were used for the experiments. The femoral neck was fractured transcervically and devascularized. Total devascularinations were performed in the majority of the animals. The animals …

The Relationship Between The Systemic Action Of Various Carbohydrates And The Development Of Subsequent Dental Caries, Pat O. O'Day

Loma Linda University Electronic Theses, Dissertations & Projects

Previous work with rats, hamsters and monkeys has shown a direct relationship between refined diets high in carbohydrates and caries susceptibility. Adequate amounts of vitamins and minerals have been shown to be necessary for proper tooth development and resistance to decay. The glycoprotein content of hamster teeth raised on a non-cariogenic Purina ration was reported to be lower than the amount found in the teeth of animals raised on a high sugar cariogenic diet.

In order to determine the caries susceptibility produced in Albino rats by different common carbohydrates, an artificial feeding technique was utilized in which the amount and …

Some Supplementary Studies With Wheat Proteins, Gerald G. Porter

Loma Linda University Electronic Theses, Dissertations & Projects

[Abstract Not Included]

Introduction The importance of selecting only foods containing proteins of high nutritive value has been somewhat over-emphasized in the past because of the failure to recognize the possibility of supplementary relationships among proteins that are not of high quality. Hart (11) has wisely suggested that a food should not be relegated to an inferior class because its proteins, when fed alone, are not of high biological value. Sherman (31) has reminded us that with a knowledge of the nutritional chemistry of the proteins of various foods, it becomes relatively easy to utilize their supplementary relationships so that …