Two groups of cows were fed a ration in which three pounds of a grain mixture was used to every four pounds of hay. Two cows (Test Tube and Deborah) were fed Timothy hay with a grain mixture containing yellow corn. The other three cows (Dolly, Connie and Dot) were fed Alfalfa hay with a grain mixture containing white corn. The grain was also modified for protein balance. Relationships of carotene and Vitamin A concentrations in the blood, milk and feed were then studied. An attempt was made to correlate the various factors involved, the variables being: period of gestation; time after calving; intake of the vitamin and its precursor in the feed; milk produced; percent of the concentration of Vitamin A activity of blood and milk represented by carotene; total Vitamin A activity of the same; and, the efficiency of the secretion in the milk of the Vitamin A activity of the feed ration. The methods of determination of the carotene and Vitamin A (together constituting the Vitamin A activity) are given with details of the calculations. Milk was collected on the first, third and fifth day after calving and at approximately monthly intervals thereafter. Having begun the experiment with the cows in various stages of gestation, it was possible to obtain only six samples from Dot while ten were collected from others. The blood samples also were taken monthly. The feeds were analyzed at three monthly intervals and the rate of loss of Vitamin A activity observed. Minimum values were used in all calculations. / M.S.

A brief investigation was made of various organic and inorganic solvents for the dissolution of urinary calculi in vitro and Albright’s (1) citric acid buffer and a solvent designated in this investigation simply as “G” (33) were shown to be the most efficient solvents. Further investigation showed that something was necessary to increase the efficiency of these solvents, as the dissolution would proceed to a certain point where the solvent ceased to act. It was at this point that the investigation changed its course and the attack was centered on the organic colloidal matrix in the structure of the stone. It is a well known fact that this organic matrix is resistant to weak acids and bases (30) and therefore the course of the investigation pointed to those most remarkable agents, “the enzymes”, which due to their enormous amount of surface energy are capable of producing astonishing results. The enzymes investigated were not selected for their specific action, but they were selected for the purpose of studying the effect of their surface energy on the colloidal matrix of urinary calculi. The investigation indicates that a calculus pretreated with urease for fifteen minutes, followed by a 6 hour irrigation with “G” (33) solution is sufficient to cause dissolution and disintegration in nearly all of the one hundred calculi selected at random. (See Table 5) The ability of urease to hasten disintegration may be due to its activity on the colloidal matrix, causing it to swell, thereby giving back the former hydrotropic properties mentioned by Snapper (52). Colloidal material was isolated from a large calculus and was subjected to the action of urease. After 6 hours the colloids from the calculus had swollen approximately five hundred times their original volume, and changed from a dark brown-colored material to a white translucent gel. These organic colloidal matrices of urinary calculi are apparently of a reversible nature and irreversible as investigators have assumed in the past (30). Investigations were made and reported in various sections of this paper on the ability of other enzymes, peroxide, and acids to act as dissolution agents or as aids to dissolution. An efficient in vitro irrigator Fig. 1 is described and its merit in the irrigation of urinary calculi lies in the facts that its construction is simple, its rate of flow can be accurately regulated by a slight manipulation, and the calculus can be treated in various ways without removing it from the original crucible. It now remains for the urologist to investigate the possibility of in vitro dissolution, using the above auxiliary agent. It is suggested that the urease might be used simultaneously with the irrigation solvent. / Ph. D.

M.S.

M.S.

M.S.

On the basis of the present data it would seem that there is no marked relationship between the surface tension and the degree of polymerization of nitrocellulose solutions of normal butyl acetate as determined by the Du Nouy method. It should be noted that no great precision is present in the recorded data. A slight change in surface tension due to a difference in the degree of polymerization could easily be more than offset by errors in measurement. The solutions become much more viscous with increased concentration. This limited the range over which the surface tension could be measured with any degree of accuracy. For with highly viscous solutions the ring would be pulled slowly from the surface making it extremely difficult to determine the exact force required for the break. A second effect was that with increasing concentration a film of the solution adhered across the ring. The data indicates that there is no great change in the surface tension with varying concentration within the range studied. / M.S.

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Montréal Trigonix inc. 2018

University of Macau / Faculty of Arts and Humanities. / Department of Chinese

University of Macau / Faculty of Social Sciences and Humanities / Department of Chinese