Theodor von Brand

Observations on function, composition, and structure of cestode calcareous corpuscles

Abstract 1. 1. Taenia taeniaeformis contains about half as much calcareous corpuscle material as does Cysticercus fasciolaris. The corpuscles show no quantitative gradient along the strobila of Taenia taeniaeformis, but the larger individual proglottids contain more corpuscle material than the smaller ones. 2. 2. More calcareous material disappears from Cysticercus faciolaris during anaerobic than during aerobic incubation in non-nutritive media. In both cases considerably more corpuscle material disappears when the worms are incubated in slightly acid than in slightly alkaline surroundings. It is concluded that the corpuscles serve to buffer acids entering the body from the outside and, possibly, to buffer acids produced during aerobic and anaerobic fermentations. 3. 3. The corpuscles yield Ca, Mg, P, and CO2. The mineral component of the corpuscles is amorphous, but upon heating with KOH crystallization takes place and brucite and hydroxyapatite crystals are formed. The carbonates, however, do not crystallize. 4. 4. Electron microscopy indicates that the lamellae of the corpuscles may be paired rings. It reveals also an amorphous or granular background substance, but no crystalline elements. 5. 5. The inorganic material of the corpuscles can readily be demonstrated by various histochemical staining methods. It is also possible to demonstrate histochemically a glycogen-like polysaccharide, a mucopolysaccharide, lipids, and proteins as constituents of the organic base of the corpuscles.

STUDIES ON THE ANAEROBIC METABOLISM AND THE AEROBIC CARBOHYDRATE CONSUMPTION OF SOME FRESH WATER SNAILS

1. Lymnaeidae and Physidae tolerated complete lack of oxygen less well than Planorbidae or operculates belonging to different families.2. All species consumed carbohydrate under anaerobic conditions and produced carbon dioxide and lactic acid. While in several species the lactic acid produced was sufficient to account for all or a large part of the carbon dioxide as liberated from bicarbonate, this was not the case in other species.3. The anaerobic metabolic level as measured by carbon dioxide production and carbohydrate consumption of the resistant species was, on an average, lower than that of the nonresistant ones. The former did not accumulate lactic acid within their tissues during an anaerobic period, while the latter did so to a marked degree.4. In most species the anaerobic carbohydrate consumption was only slightly higher than the aerobic rate. One of the reasons for this may be the probable occurrence of aerobic fermentations in these species.5. Lactic acid was quantitatively a major end product...

Observations on the metabolism of bacteria-free larvae of Trichinella spiralis

Abstract 1. 1. The larvae of Trichinella spiralis consume aerobically and anaerobically about the same amount of glycogen, while lipid consumption occurs only under aerobic conditions. 2. 2. The major endproducts of the carbohydrate fermentation are volatile fatty acids, especially valeric acid, while only traces of lactic acid are produced. Keto substances in small amounts are produced only in the presence of oxygen. Part of the acids is excreted as free acids, while another part may be excreted in the form of ammonium salts. 3. 3. Carbohydrate fermentation is the process which allows the larvae to survive anaerobic processes, but it is insufficient to allow motility. It is probable that a major part of the oxygen consumed is used for the oxidation of lipids and this process may be of importance for the motility of the larvae.

FURTHER STUDIES ON THE ANAEROBIC METABOLISM OF SOME FRESH WATER SNAILS

1. Fresh water snails exposed to anaerobic conditions produce volatile acids which are partly. excreted into the medium and partly accumulate in the tissues.2. The acids formed by Australorbis glasbratus and Helisoma duryi were identified by chromatographic means and crystallographic data as propionic and acetic acids.3. While bacterial formation of these acids cannot be excluded categorically, some evidence is adduced to the effect that they may be produced by the snail tissues.4. The evidence indicates that the species not resistant to anaerobiosis are killed primarily by the accumulation of lactic acid, while the resistant species are more tolerant to the lack of oxygen due to the fact that they accumulate in their tissues the less toxic fatty acids rather than lactic acid.5. Most of the carbon dioxide evolved by anaerobically kept snails is of direct inorganic origin.

CO2 fixation studies with the culture form of Trypanosoma cruzi

Abstract 1. 1. Succinate production of the culture form of Trypanosoma cruzi is completely dependent on CO2 under anaerobic conditions; under aerobic conditions CO2 greatly enhances succinate production. 2. 2. Anaerobically, variously labeled species of glucose-C14 are metabolized in a way consistent with the Embden-Meyerhof glycolytic scheme followed by CO2 fixation on pyruvate, resulting in the formation of succinic acid. 3. 3. Aerobically, succinate is formed by two pathways. First, experiments with variously labeled species of glucose-C14 indicate that a large part of the glucose is metabolized according to the Embden-Meyerhof scheme followed by the tricarboxylic acid cycle. Second, succinate is also formed by CO2 fixation. 4. 4. Succinate formed either by tricarboxylic acid cycle reactions or by CO2 fixation is partly excreted into the medium. Part of the succinate formed, as well as the precursor dicarboxylic acids of the second pathway mentioned above, appear to be further metabolized by the tricarboxylic acid cycle, since malonate increases the yield of succinate while causing no significant change in CO2 production. It is therefore considered that the intermediates of both pathways are mixed in the cell.

The sterols of Trypanosoma cruzi and Crithidia fasciculata

Abstract 1. 1. Six sterols have been detected in Trypanosoma cruzi cultured on serum-free medium. Four of these are ergosterol, 22,23-dihydroergosterol, 7-dehydroporiferasterol and 7-dehydroclionasterol (or their C24 isomers from which they cannot be distinguished with the small quantities available). The remaining two sterols may be 24-methylene-7-dehydrocholesterol and 24-ethylidene-7-dehydrocholesterol but this has not been proven. 2. 2. In addition to these six sterols, cholesterol is also a major component of T. cruzi cultured in the presence of serum. 3. 3. Ergosterol (or its C24 isomer) was the only sterol detected in Crithidia fasciculata cultured in serum-free medium. When grown in the presence of serum the cells also contained cholesterol and 22,23-dihydroergosterol (or its C24 isomer).

Studies on the metabolism of Echinococcus granulosus: I. General chemical composition and respiratory reactions

Abstract 1. 1. Hydatid cyst scolices contain large amounts of protein and smaller amounts of lipids. Less inorganic substances are present than in other immature tapeworms. Two polysaccharides are stored: glycogen and a polysaccharide containing galactose and glucosamine. 2. 2. Under an oxygen tension of atmospheric air the scolices consume oxygen at a rapid rate (Q o 2 = 2) with an over-all RQ of 0.88. 3. 3. The anaerobic CO 2 production is pronounced, but the sources of this CO 2 have not been established. 4. 4. The aerobic and anaerobic gaseous exchanges are highly sensitive to inhibitors of glycolysis, but dl -glyceraldehyde is completely ineffective. 5. 5. The aerobic respiration is markedly cyanide sensitive. 6. 6. The aerobic respiration is inhibited by fluoroacetate, but not by malonate. 7. 7. The Q 10 of the oxygen consumption is 2.1 in the range 28 to 38 °C. Temperatures of 42 and 45 °C are beyond the optimum. 8. 8. The respiration remains about constant in the pH range 4.5 to 8.5. 9. 9. The ionic composition of the medium has a considerable influence on the respiratory rate, hydatid cyst fluid and Ringers solution sustaining the respiration best.

Formation, isolation and composition of dense granules from mitochondria

Abstract 1. 1. An investigation was undertaken to determine if the electron-dense granules which accumulate in mitochondria under conditions of massive Ca 2+ -loading could be isolated and identified. 2. 2. Four methods are described for the isolation of dense granules from rat liver mitochondria. Three of these methods involve chemical destruction of the mitochondria. and liberation of the granules; the fourth involves disruption by sonication. 3. 3. The granules are amorphous, and consist of both organic and inorganic constituents. 4. 4. Incineration of the granules destroyed the organic moiety and induced crystallization of the inorganic constituents. 5. 5. Chemical analysis disclosed that Ca 2+ and P i are the major inorganic constituents. Mg 2+ and CO 2− 3 also are present in significant amounts. 6. 6. X-ray diffraction analysis indicated that the patterns of the incinerated granules correspond to either hydroxyapatite, Ca 10 (PO 4 ) 6 (OH) 2 , whitlockite, Ca 3 (PO 4 ) 2 , or to a mixture of both. 7. 7. The isolation of the granules enabled a study of some of the factors which influence this active ion translocation in a more direct way than was hitherto possible.

Electron microscopy of cestode calcareous corpuscle formation.

Abstract The formation of calcareous corpuscles in the common cat tapeworm, Taenia taeniaeformis , is described. The corpuscle forms in a cytoplasmic cavity, and the corpuscle-forming cell appears to expend itself in the production of one corpuscle. Two corpuscular components were recognized: a homogeneous matrix that may correspond to one of the organic moieties known to be present in corpuscles, and a granular substance that may represent inorganic material. The corpuscle enlarges by the accretion of these two components in concentric layers with progressive compression of the surrounding cytoplasm.

Chemical composition of the culture form of Trypanosoma cruzi.

Abstract 1. 1. The culture form of T. cruzi contains considerably more lipids than carbohydrates. 2. 2. No glucose polysaccharide was found. A galactose-containing polysaccaride was observed but it could not be separated from nucleic acid derivatives. 3. 3. The nature of the nucleic acid derivatives indicated that T. cruzi contains both deoxyribonucleic acid and ribonucleic acid, the latter representing in part at least the volutin granules. 4. 4. A large part of the unsaponifiable fraction consists of cholesterol. The presence of a small amount of a 5,7-diene was indicated by ultraviolet spectroscopy.