Hemolytic complement in nonhuman primates

Hemolytic serum complement activity was quantitatively compared in baboons, squirrel monkeys, cebus monkeys, and cotton-top marmosets. Squirrel monkeys showed the highest activity, and marmosets had the lowest activity. The complement level in squirrel monkeys and tenfold greater than marmosets and almost four times higher than that of man. Cebus monkeys had levels most similar to that of man while the baboon exhibited activity almost as low as that of the marmoset.     

Diterpenoids from Ajuga chamaepitys: Two neo-clerodane derivatives

From the whole plant of Ajuga chamaepitys two new neo-clerodane diterpenoids, ajugapitin and its dihydro derivative, have been isolated. Their     

Severe mental deficiency,proportionate dwarfism,and delayed sexual maturation

Summary Two 46,XY brothers were found to have a previously undescribed syndrome characterized by severe mental deficiency, proportionate dwarfism, and delayed sexual development. A recessive mode of inheritance, either autosomal or X-linked, is assumed.     

Head movements of the mealworm beetle Tenebrio molitor

Tethered walking imagines of the mealworm beetle Tenebrio molitor wave their heads in random fashion. If a periodic pattern of vertical black and white stripes is rotated around the animal a regular nystagmic head movement is superimposed upon the random waving, the frequency of the latter equals the contrast frequency within large ranges of the angular velocity of the pattern. The nystagmus is inverted: After a short period of tracking, during which the angular velocity of the head is the same as that of the panorama, the head returns slowly toward its normal position according to an exponential-like function. Resting animals do not wave their heads. However, if the above panorama is rotated, the beetle turns its head in the direction of the movement of the panorama and holds it in a side-way position, as long as the rotation is maintained. The angular position reached depends in the same manner on the angular velocity of the panorama as the turning tendency of walking animals established in open loop experiments using the spherical Y-maze method.     

1H-NMR studies on the binding subsites of bovine pancreatic ribonuclease A

The titration curves of the C-2 histidine protons of an RNAase derivative (a covalent derivative obtained by reaction of bovine pancreatic RNAase A (EC 3.1.27.5) with 6-chloropurine 9-beta-D-ribofuranosyl 5'-monophosphate) were studied by means of 1H-NMR spectroscopy at 270 MHz. The interaction of natural (5'AMP, 5'GMP, 5'IMP) and halogenated purine mononucleotides (cl6RMP, br8AMP) with RNAase A was also monitored by using the same technique. The slight change observed in the pK values of the active centre histidine residues of the RNAase derivative, with respect to those in the native enzyme, can be considered as evidence that the phosphate of the label does not interact directly either with His-12 or 119 in the p1 site, but the p2 site as proposed previously (Parés, X., Llorens, R., Arús, C. and Cuchillo, C.M. (1980) Eur. J. Biochem. 105, 571--579). Lys-7 and/or Arg-10 are proposed as part of the p2 phosphate-binding subsite. The pK values of His-12 and 119 and the shift of an aromatic resonance of the native enzyme found on interaction with some purine nucleotides, can be interpreted by postulating that the interaction of 5'AMP, 5'GMP and 5'IMP takes place not only in the so-called purine-binding site B2R2p1 but also in the primary pyrimidine-binding site B1R1 and p0 of RNAase A.     

Sublingual structures of primates. II. Hominoidea, review, summary and literature

1. In Homo and the great apes (Pongidae) there occurs, besides the plica sublingualis a plica fimbriata at the ventral surface of the tongue. This duplicature of the mucosa does not occur in the Hylobytidae and in the other primates. 2. Some taste buds could be found in the epithelium of the plica sublingualis of the Pongidae. 3. There are many taste buds in the epithelium of the plica fimbriata of the Pongidae. On this sublingual structure there were counted 1776 taste buds in Pongo, 592 in Gorilla and 280 in Pan. A few taste buds could also be found on the plica fimbriata of a human newborn. 4. A glandula apicis linguae occurs in Homo, Pan, Gorilla and Pongo. 5. The fresh saliva of the glandula apicis linguae and the saliva on the floor of the mouth can be tested by the taste buds in the epithelium of the plica fimbriata, of papillae lenticulares and of areae gustatoriae at the ventral surface of the tongue. 6. It might be the function of the sublingual taste buds to taste the fresh saliva as a gradient for the central nervous comparison with the taste of the saliva on the dorsal surface of the tongue. 7. Because of the complete absence of a sublingua in the Platyrrhini and in the Cercopithecinae it is unlikely that the plica fimbriata of Homo and the great apes can be interpreted as a homalogon of the sublingua in the prosimians. 8. Because of the absence of a sublingua in other ordines of the Mammalia (Insectivora, Carnivora, Rodentia, Chiroptera, Ungulata) it is unlikely as well that the sublingua in the prosimians can be interpreted as a homologon of the tongues of the lower vertebrates. The sublingual structures occuring in the Marsupialia have to be investigated. 9. Because of these reasons the new development of the sublingua in the prosimians and the plica fimbriata in the Hominoidea, in complete independence from one another, seems to be a better explanation of the 2 structures and less contradictionary to anatomical and phylogenetic arguments. The different function of both structures in the recent primates gives a hint for the possible reason for their development during the process of evolution.     

Ammonia overloading in hepatocytes isolated from liver of fetal and adult rats

Ammonia overloading was investigated during glucose and fructose metabolism in isolated hepatocytes under a variety of metabolic conditions. In all assay conditions, the glycolytic flux and oxygen uptake was not modified by 10 mM ammonia. In hepatocytes isolated from rats fed as libitum, the presence of ammonia caused a decrease in the production of lactate (pyruvate); this effect was not observed in anaerobic incubations, in hepatocytes isolated from starved animals, or in fetal hepatocytes. In spite of an overproduction of urea, ammonia detoxification also takes place by the synthesis of alanine, glutamate and aspartate. Addition of 1 mM aminooxyacetate, an inhibitor of aminotransferases, to the incubation medium prevents the formation of these amino acids, and also prevents the decrease of lactate in hepatocytes isolated from fed animals.