Isolation and characterization of human heart cytochromec oxidase

Cytochromec oxidase was isolated from human hearts and separated by SDS gel electrophoresis. The identity of polypeptide bands with known subunits was demonstrated by immunoblotting with monospecific antisera to rat liver cytochromec oxidase subunits. The polarographically determined kinetics of cytochromec oxidation were similar to those reported for the bovine heart enzyme.     

Regulation of respiration and ATP synthesis in higher organisms: Hypothesis

The present view on the regulation of respiration and ATP synthesis in higher organisms implies only Michaelis-Menten type kinetics and respiratory control as regulatory principles. Recent experimental observations, suggesting further regulatory mechanisms at respiratory chain complexes, are reviewed. A new hypothesis is presented implying regulation of respiration and ATP synthesis in higher organisms mainly via allosteric modification of respiratory chain complexes, in particular of cytochromec oxidase. The allosteric effectors, e.g., metabolites, cofactors, ions, hormones, and the membrane potential are suggested to change the activity and the coupling degree of cytochromec oxidase by binding to specific sites at nuclear coded subunits. Recent results on the structure and activity of cytochromec oxidase, supporting the hypothesis, are reviewed.Dedicated to Professor Dr. Carl Martius on the occasion of his 80th birthday.     

Fermentative degradation of monohydroxybenzoates by defined syntrophic cocultures

From anaerobic freshwater enrichment cultures with 3-hydroxybenzoate as sole substrate, a slightly curved rod-shaped bacterium was isolated in coculture with Desulfovibrio vulgaris as hydrogen scavenger. The new isolate degraded only 3-hydroxybenzoate or benzoate, and depended on syntrophic cooperation with a hydrogenoxidizing methanogen or sulfate reducer. 3-Hydroxybenzoate was degraded via reductive dehydroxylation to benzoate. With 2-hydroxybenzoate (salicylate), short coccoid rods were enriched from anaerobic freshwater mud samples, and were isolated in defined coculture with D. vulgaris. This isolate also fermented 3-hydroxybenzoate or benzoate in obligate syntrophy with a hydrogen-oxidizing anaerobe. The new isolates were both Gram-negative, non-sporeforming strict anaerobes. They fermented hydroxybenzoate or benzoate to acetate, CO₂, and, presumably, hydrogen which was oxidized by the syntrophic partner organism. With hydroxybenzoates, but not with benzoate, Acetobacterium woodii could also serve as syntrophic partner. Other substrates such as sugars, alcohols, fatty or amino acids were not fermented. External electron acceptors such as sulfate, sulfite, nitrate, or fumarate were not reduced. In enrichment cultures with 4-hydroxybenzoate, decarboxylation to phenol was the initial step in degradation which finally led to acetate, methane and CO₂.     

Microbial populations in wetwood of European white fir (Abies alba Mill.)

Abstract A method for extraction of microbial populations from wood samples was worked out which gave good recovery of both aerobic and anaerobic microorganisms in agar shake dilution and plating enumerations. This method was applied to the quantification of microbial populations in three European white firs ( Abies alba Mill.) which were afflicted with the European fir disease. Low numbers of aerobic microorganisms (10²−10⁴ colony- forming units (cfu) per g fresh tissue) were detected in sapwood irrespective of the degree of affliction. Anaerobic bacteria were usually 1–2 orders of magnitude less frequent. Wetwood of highly diseased firs contained significantly higher numbers of aerobic microorganisms (10⁵−10⁷), whereas the number of anaerobes was not enhanced significantly. Among the prevalent aerobic microorganisms in wetwood were Protaminobacter, Pseudomonas strains, and a yeast. In anaerobic counts from wetwood, Klebsiella and Vibrio strains predominated. The sapwood contained Bacillus, Beijerinckia, Staphylococcus , and Clostridium spp. High numbers of aerobic microorganisms were also detected in the roots and lower stem of a diseased vine plant ( Vitis vinifera L.). The importance of microbial populations in wetwood formation and disease expression is discussed.     

Ethnogenesis of South Asia with special reference to India

An attempt has been made to illustrate the quite complicated process of ethnogenesis in South Asia from the viewpoint of physical anthropology. The numerous invading waves which reached the Indian subcontinent from the northwest played an important role in this process. Most important for the ethnogenesis of South Asia was the invasion of Indo-Aryan groups in the middle of the 2nd millenium B.C. known from historical sources. In large parts of the Indo-Pakistan region they assimilated the aboriginal population in ethnic, cultural and linguistic respects in the course of time. Furthermore, the ethnogenesis of the Indian region is determined by the caste system of Hinduism which, however, is not as rigid as generally assumed. There are numerous evidences that since more than 2000 years a slow but steady process of assimilation and integration of tribal groups, living in the forest areas of Central India, into the Hindu caste system took place, a process which is still going on. It is intended to demonstrate to what degree the ethnogenetic processes in South Asia, known from prehistoric and historical sources, can be traced in human skeletal findings of different time periods as well as in the anthropological structure of the living population. Finally, hypotheses and theories, especially those of Risley and von Eickstedt are discussed, who attempted to interpret the great variability of anthropological and morphological traits in the Indian subcontinent by taking into consideration the existence of different old population substrata and their mixing and assimilation.     

Alterations in lymphocyte homing patterns within mice exposed to ultraviolet radiation

This report presents the results of an investigation designed to establish whether exposure of mice to ultraviolet radiation (UVR) is capable of influencing the factors that control the distribution of lymphoid cells in vivo. We found that such exposure resulted in a dramatic and long-lasting increase in the tropism of peripheral lymph nodes for circulating lymphoid cells. Termination of UVR exposure did not result in a reversal of this phenomenon. Since an increase in lymphocyte migration into the lymph nodes of UVR-exposed mice was apparent within 2 hr of infusion of the radiolabeled cells, we conclude that the homing assay data reflect a relatively increased binding of circulating lymphocytes to high endothelial venules (HEV) within the lymph nodes of irradiated animals. A histologic analysis of skin from UVR-exposed mice established that the dermal microvasculature had expanded in terms of size and number of vessels, a condition that also does not completely reverse after the termination of treatments. In spite of the increase in dermal microvasculature, very few inflammatory cells were detected in the irradiated skin site. These observations support our conclusion that the enhanced traffic of lymphocytes into peripheral lymph nodes of UVR-exposed mice occurs primarily via lymphocyte-HEV interactions rather than afferent drainage of the irradiated skin.     

The in vitro synthesis and characteristics of ribosomal RNA in imaginal discs of Drosophila melanogaster

Summary Late third instar imaginal discs of Drosophila melanogaster cultured in vitro in Robb's tissue culture medium synthesize 38S, 28S and 18S ribosomal RNAs which are qualitatively indistinguishable from their in vivo synthesized counterparts (Fig. 1). As found in other insect systems, the 38S molecule appears to be the precursor for both the 28S and 18S rRNAs (Figs. 2, 3 and 4). The 28S rRNA and a portion of the 38S pre-rRNA shift in sedimentation value upon exposure to heat or dimethylsulfoxide (Figs. 5 and 8). Studies of the thermal denaturations of these molecules (Figs. 6, 7 and 9) indicate the existence of a single class of 28S rRNA, but three classes of 38S pre-rRNAs. The addition of -ecdysone to the in vitro culture medium stimulates the net amount of rRNA synthesized, increases the rate of processing of the 38S precursor and increases the relative amount of 18S material produced (Figs. 10 and 12).This work was supported in part by grants from the National Science Foundation (GB-8176) and from the Atomic Energy Commission (AT-04-3-34).Predoctoral Trainees, PHS Training Grant No. 2-Tl-GM367 from Research Training Grants Branch, National Institute of General Medical Sciences.1 For purposes of simplification we shall refer to the rRNA molecules of D. melanogaster as being 38S, 30S, 28S and 18S; however, it should be noted that these values are approximate (see Hastings and Kirby, 1966; Greenberg, 1969; Tartof and Perry, 1970).     

Stephanoscyphus Allman (Scyphozoa Coronatae), ein rezenter Vertreter der Conulata?

The scyphopolypStephanoscyphus Allman 1874 represents the polyp generation of the scyphomedusan order Coronatae. The benthonic polyp is known to occur with several species on the continental shelves and in greater depths of the oceans. Participating in the International Indian Ocean Expedition 1964 to 1965 on board of the German research vessel «Meteor», the author was able to collect living specimens. For the first time, it was possible to rear these polyps in laboratory cultures.Stephanoscyphus differs from all other living scyphopolyps by the possession of a firm periderm tube enclosing completely the soft body. It is this primitive feature whichStephanoscyphus has in common with the Conulata being the ancestors of the recent Scyphozoa. The characteristics found in a detailed investigation of the periderm tube ofStephanoscyphus conform well with those found in the tubes of the Conulata except for the closure of the aperture by triangular flaps which are absent inStephanoscyphus. The soft body contains primitive features as well. Hence from the existence, morphology and life history it must be concluded that the type of organization which the Conulata exhibited has survived inStephanoscyphus.