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Two-dimensional chromatography on commercially available silica gel-loaded paper for the microanalysis of polar lipids from various tissues is described. All common phospholipids and their lyso derivatives can be reproducibly separated. As many as 22 lipid components were separated on a single chromatogram. Improved methods for staining lipids and for determining phosphorus in the chromatographic spots are reported.

Commercial silica gel loaded filter paper has been found to give good separations of neutral lipids and phospholipids. Unidimensional or two-dimensional chromatography can be used. Rat liver lipids and C14-algae lipids were studied. An advantage over thin-layer chromatography is that several spot tests can be applied on the same chromatogram.

Improvements in the detection of phospholipids on paper chromatograms by neutron activation (with the formation of P32-compounds) have been made. Formaldehyde-treated papers were subjected to low neutron dosage after chromatographic development and the resulting radioactive spots were detected by automatic scanning and autoradiography.

The separation of dog serum lipoproteins by ultracentrifugation at a density of 1.063 is hindered by the failure of the high density fraction to accumulate in the bottom portion of the centrifuge tube. This phenomenon interferes with the quantitative recovery of pure low density lipoproteins. By paper electrophoresis, a lipid-containing protein with the mobility of a β-globulin was detected in the lowest layer of the centrifuge tube. Comparison of the preparative ultracentrifuge technique with that of dextran sulfate precipitation of β-lipoproteins revealed the suit ability of the latter procedure for the quantitative separation of β-lipoproteins. The dextran sulfate β-lipoprotein precipitate was shown to be free from α-lipoprotein by paper electrophoresis.

A rapid chromatographic procedure was developed for the separation of sphingomyelin, phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl serine, phosphatidyl inositol, and free fatty acids on glass paper coated with sodium silicate. In addition, phosphatidyl choline and sphingomyelin were determined quantitatively by densitometry of the charred chromatogram, which was obtained by spraying the developed chromatogram with sulfuric acid and heating in an oven. The separation of phosphatides on sodium silicate-treated glass paper is more rapid than on silicic acid-impregnated paper, and the former is simpler to prepare. Preliminary application of this quantitative technique to human serum indicates that it may have a wide adaptability for the determination of phospholipids in natural products.

O grande impulso que têm tornado, nestes últimos anos, as investigações sôbre a doença de Chagas, não sòmente em Minas Gerais, como também em outros Estados do Brasil e países do novo continente atingidos pela endemia; o interêsse cada vez mais crescente por parte dos médicos em geral e a facilidade com que vêm sendo por êles assimiladas as recentes contribuições ao estudo desta entidade mórbida; a importância médico-social e a repercussão econômica que tem sido atribuída à esquizotripanose como fator de letalidade e de incapacidade relativa ou total para o trabalho, depois de conhecidos os resultados de inquéritos clínico-epidemiológicos realizados em zonas infestadas por triatomíneos; a recente adoção, por parte das autoridades responsáveis pela saúde publica, de medidas concretas de contrôle da doença pelo combate aos seus transmissores domiciliares, por meio de inseticidas de ação residual aplicados em larga escala; e, principalmente, a escassez de trabalhos de conjunto e de fácil acesso, com referencias bibliográficas adequadas e extensas, que facilitassem aos não especializados no assunto, o conhecimento e a consulta das investigações já realizadas sôbre êste importante problema de medicina tropical; tais são os principais motivos que sugeriram a elaboração de um esbôço crítico do desenvolvimento dos trabalhos até agora publicados sôbre a esquizotripanose em Minas Gerais. De fato, foi aí descoberta a nova entidade mórbida do homem, foram aí estudados e esclarecidos problemas relativos à etiologia, epidemiologia, aspectos clínicos e anatomo-patológicos da esquizotripanose, foram aí realizadas investigações experimentais e desenvolvidos métodos de profilaxia, constituindo, em conjunto, os trabalhos realizados sôbre a esquizotripanose em Minas Gerais, fundamentados nos alicerces sólidos legados pelo seu grande descobridor, uma obra verdadeiramente monumental, que tanto orgulha e engrandece a ciência latino-americana. Os trabalhos publicados sôbre a doença de Chagas em Minas Gerais, compreendendo tôdas as inves tigações aí realizadas e as contribuições que com material procedente do Estado se realizaram fora dêle, foram divididos em cinco grandes grupos: l.º) — Trabalhos realizados em Lassance 2.º) — Trabalhos realizados em Bambuí 3.º) — Trabalhos realizados em Belo Horizonte 4.º) — Trabalhos realizados em outras zonas do Estado 5.º) — Profilaxia da doença de Chagas em larga escala. I) — Os trabalhos realizados em Lassance cobrem um longo período de quase 30 anos, período êsse que vai desde 1909, data da descoberta de um novo tripanosoma e da descrição da nova entidade mórbida do homem feita por CHAGAS, ate 1936, data da publicação de trabalhos de pesquisadores de Manguinhos, apresentados no ano anterior à Nona Reunião da Sociedade Argentina de Patologia Regional convocada em homenagem à memória do grande tropicalista brasileiro CARLOS CHAGAS. Pràticamente, as pesquisas desenvolvidas em Lassance e os trabalhos realizados com o abundante material que de lá foi canalizado para o Instituto Oswaldo Cruz — investigações condensadas em uma centena de publicações — foram feitas por CHAGAS e colaboradores durante a vida do descobridor da esquizotripanose. Neste período, CHAGAS e pesquisadores que, sob sua orientação, trabalharam em Lassance e Manguinhos, descreveram a nova doença nas suas diversas...The critical study of the papers published up to 1951 on Chagas' disease in the State of Minas Geraes (Brazil), was divided into five chapters: 1) Work made in Lassance; 2) Work made in Bambuí; 3) Work made in Belo Horizonte; 4) Work made in other parts of the State; 5) Large-scale prophylaxis of Chagas' disease. 1) The work made in Lassance covers a long period of almost 30 years, from 1909, when a new trypanosoma was discovered and the corresponding disease was described by Chagas, up to 1936. The researches made in Lassance were carried out by Chagas and its co-workers of the Oswaldo Cruz Institute. During this period they described the various clinical features of the new disease, made a detailed study of its agent and the biology of the transmitting insects, and experiments and studies on the pathogeny and pathology of the disease; they developed diagnostic methods, analysed the role of domiciliary and wild reservoirs, and insistently showed the social significance of this sanitary problem. 2) The research work made on Chagas' disease in Bambuí contributed decisively for the growing interest on the study of this disease during the last few years. Although the work in Bambuí was carried out continuously since its beginning in 1940, the researches may be divided into two groups, namely the preliminary made before the installation in the mentioned city of the Center for the Study and Prophylaxis of Chagas' Disease in November 1943, and the work done after the installation of the Center. The first group represents the first contribution after the researches carried out in Lassance, towards a formal study of acute cases of Chagas' disease in the State .The finding of numerous acute cases at Bambuí led the direction of the Oswaldo Cruz Institute to create a Center of Studies in that city. An outstanding contribution on the clinical, epidemiological and prophylactic fields was brought about by investigators of Manguinhos with the abundant material supplied by the Bambuí Center. The chief contributions from Bambuí were of three kinds: a) The individualization of the chronic Chagas' heart disease on clinical, anatomo-pathological, electrocardiographic and experimental basis; the demonstration of its great frequency in infected individuals and the verification that in certain rural areas schizotrypanosis is one of the most important etiological factors of heart disease. b) The experience acquired with the use of the complement fixation reaction with antigens of cultures of Schizotripanum cruzi allowing a rapid and safe confirmation of chronic cases of schizotrypanosis. The reaction, if done in a large-scale, make it possible to get a fairly accurate idea on the incidence of Chagas' disease in endemic areas. c) The possibility of performing prophylactic campaigns by using proper residually acting insecticides. 3) — An examination of the literature on the subject shows a delayed interest of scientifc investigators and clinicians of Belo Horizonte on the study of Chagas' disease, since the first papers are dated 1930...

Chromatographic procedures for the detection and evaluation of oxygenated fatty acids are described. Emphasis has been placed on epoxy acids, but these methods promise to be of great value in studies of all classes of oxygenated acids. Paper chromatography of fatty acids and their esters has been developed for the examination of mixtures containing oxygenated derivatives. The method of adsorption chromatography on thin layers of silicic acid has been shown to be a powerful tool in studies of epoxy acids and hydroxy acids. Gas-liquid chromatography (GLC) of epoxy esters has been studied using both polar and nonpolar columns and has great utility in the detection and analysis of these compounds in mixtures. These methods have been applied to the examination of the epoxy components of six seed oils. Thin-layer and GLC proved particularly useful in this study and together demonstrated the presence of at least three distinct epoxy acids in each of these oils. Some conclusions as to the probable structures of these epoxy components are presented on the basis of their chromatographic characteristics in relation to known substances.

A rapid, sensitive method for the determination of sterols is described. Microgram samples are spotted on impregnated glass fiber paper, chromatographed for 7 minutes, dried, sprayed with sulfuric acid, and charred by heating. The amount of char formed is measured by densitometry. Values obtained for cholesterol in the serum are in agreement with those obtained by the Sobel-Mayer method. The method has been adapted to the determination of cholesterol in 10 μl. of plasma, and to the determination of standard solutions of other sterols.

The precipitation by trichloroacetic acid (TCA) of radioactive lipids on disks of filter-paper, followed by extraction with TCA and water to remove soluble radioactive precursors, provides the means for a convenient assay for lipid biosynthesis. Large numbers of disks can be washed in the same vessel, dried, and assayed for radioactivity with liquid scintillation counting equipment. Extraction of disks with lipid solvents provides a convenient control for the possible presence of TCA- and water-insoluble, nonlipid products. The application of the method to the assay of cyclopropane fatty acid synthetase is shown.

A new paper electrophoretic method for the separation of bile acids into five groups, (1) unconjugated, (2) glycine conjugates and (3) taurine conjugates, and (4) and (5) the respective monosulfates, is described. Rapid and accurate qualitative and quantitative estimations of each group are obtained by densitometry after internal standardization and phosphomolybdate color development. The technique can be done in the routine clinical laboratory and is useful for the detection of diseases affecting the enterohepatic circulation of bile acids.