The author and co-workers (19) have already reported on estrogen excretion in male subjects with and without previous myocardial infarction. These investigations showed that following the administration of estradiol-17B a, subjects with previous myocardial infarction excrete more urinary estriol relative to estrone and estradiol-17B than the control group. This difference was not apparent in the urinary excretion when estradiol-17B was not administered.

Two six-week fluorine feeding trials were conducted with young growing guinea pigs as test animals. Basal diets were prepared that contained 75% hay since the ultimate aim of the experiment was to establish a bioassay for fluorine in forage crops. Sodium fluoride was added to the basal diets of some groups to achieve levels of fluorine ranging from 19 to 130 p.p.m. To other groups, fluorine-containing hay grown in the vicinity of a large industrial operation was fed, resulting in dictary fluorine levels of the hay-meal ration ranging from 60 to 112 p.p.m. Fluorine in the diet depressed the feed intake and weight gains of guinea pigs when its level in the complete diet approached 70 p.p.m.

From the earliest times it was known that the administration of various natural substances to man and animals had a pronounced effect on their physiological behaviour. Following the rapid development of chemistry during the latter half of the eighteenth century, many attempts were made to isolate the physiologically active substances in the natural products used in medicine. The progress in organic chemistry during the nineteenth century provided the means to study the structure and synthesise derivatives of many compounds of therapeutic value isolated from natural products, such as morphine from opium and quinine from cinchona bark.

In the short time since the structure of serotonin was first established as 5-hydroxytryptamine (1) (2) its role in human physiology has captured the interest of numerous investigators. With the discovery of variable concentrations of 5HT in different parts of the brain (3) this compound has been postulated to play a role in central transmission (4) and in mental disease (5) (6).

The reactions between antigens and antibodies constitute the essential basis of all immunological phenomena. Antibodies are proteins formed in-vivo in response to antigenic stimulation. The parameter of antigenicity, i.e., the capacity to induce antibody formation, has been found to be associated with almost all proteins thus far examined and with some lipoproteins and polysaccharides (1). In order to function as an antigen it appears that a substance must have macromolecular dimension and be recognized (by some mechanism as yet unknown) as foreign to the antibody-forming system of cells of the host (2).

Phagocytosis stimulates respiration, 'shunt' metabolism of glucose, lactic acid production and formate oxidation by the leucocytes. The stimulation of shunt metabolism of glucose during phagocytosis occurs only aerobically. Glycolytic inhibitors strongly inhibit phagocytosis. Cyanide and azide have no effect on the stimulated respiration and glucose oxidation, however, they completely inhibit the stimulated formate oxidation. Fatty acids with carbon chains from C6 to C15 inhibit phagocytosis.

To extend to tissue suspensions the work of Krebs (1950) on the design of a medium which will allow maximum respiration of tissue slices. Krebs found that with various members of the tricarboxylic acid cycle added to the medium, the oxygen uptake of sliced tissues was greatly increased (see literature review section Ib). lt was considered of interest to investigate the effect of these substrates on suspensions since these are frequently used rather than slices.

The lines of investigation from which prevailing concepts of the catabolism of phenylalanine are derived had their origin in century-old studies on the source of the benzenoid constituents of urine. The stability, in the mammalian organism, of the aromatic nucleus as it occurs in acids of the benzoic series and in alpha-aminophenylacetic acid, in marked contrast to the combustibility of phenylalanine and tyrosine, led Schotten (1883-1884) to the prophetic conclusion.

The bias in the development of biochemistry to which Baldwin (1940) drew attention in 1937 has not been remedied in the last two decades. Despite the tremendous advances in our knowledge of the biochemistry of mammals and unicellular organisms made during this period, relatively little has been added to our understanding of most other forms of life. The work reported here was undertaken because helminths are no exception, the parasitic nematode, Ascaris lumbricoides, being chosen because of its ready availability and the large size of its reproductive system.

Six trophic hormones have been extracted from the anterior lobe of the pituitary gland. The secretion and storage of these hormones takes place only in the acidophilic and basophilic cells of the anterior lobe; the chromophobe cells are believed to be inactive in these respects. It has been established that somatotrophin (STH- growth hormone) and prolactin (lactogenic hormone) are secreted by the acidophils (1-11), while thyrotropin (TSH- thyroid stimulating hormone) and the two gonadotropins (FSH- follicle stimulating hormone and LH- luteinizing hormone) are secreted by the basophils (13-22).