Effect of p-chlorophenylalanine on the reproduction of the rat (author's transl)]

The effect of p-chlorophenylalanie (p-CPA) --300 mg/kg-- on reproduction has been studied in the female rat. Groups of animals were injected with a dose of 300 mg/kg of p-CPA 48 hours before proper copulation conditions at different moments along the ovarian cycle. Presence of spermatozoa in the vaginal frotis was negative in treated rats; in the control groups however, positivity was found in variable proportions according to the phase of the ovarian cycle: 30 ad 90% in diestrus and proestrus respectively. Treated animals showed continuous diestrus phases and diffuse luteinitation of the ovary. The results may indicate that a decrease of cerebral 5-HT, caused by p-CPA, lessens the reproductive behaviour of the female rat through mechanisms depending probably on the liberation of gonadrotrophins.     

Uric acid as electronic acceptor of chicken liver's XDH (author's transl)]

Uric acid seems to act as an electronic acceptor in the dehydrogenation of hypoxanthine catalyzed by chicken liver's xanthinedehydrogenase (XDH). Oxidation was observed in crude homogenates under anaerobic conditions, although dialyzed homogenates or purified hepatic XDH also induce a similar action either in aerobic or anaerobic conditions. The reaction pH optimum is about 6.0. Xanthine appears to be the only inhibited product of the reaction when its concentration is greater than 1 X 10(-4) M. When hypoxanthine and uric acid concentrations exceed 2 X 10(-3) M and 1 X 10(-4) M, respectively, they induce inhibition by substrate. Purine is a fairly good substrate of XDH when uric acid acts as acceptor. Allopurinol inhibits hypoxanthine oxidation by uric acid in the presence of XDH. XDH also catalyzes the dismutation of xanthine to hypoxanthine and uric acid.     

Plant desiccation and protein synthesis: an in vitro system from dry and hydrated mosses using endogenous and synthetic messenger ribonucleic Acid

The conditions and requirements for an in vitro protein synthesizing system from the moss Tortula ruralis are outlined. Using this system the effects of desiccation, achieved quickly or slowly, were studied. Slowly dried moss retained fewer polyribosomes on desiccation but more active ribosomes than rapidly dried moss. Even in the completely desiccated moss the polyribosomes and/or free ribosomes present have retained their synthetic capacities. On rehydration, the slowly dried moss resumed protein synthesis more quickly than moss previously desiccated rapidly. Moss ribosomes are cycloheximide sensitive and chloramphenicol insensitive and thus the major protein synthesis occurs within the cytoplasm on rehydration. Extracted polyribosomes per se can withstand desiccation to a significant extent, suggesting that protection by the cytoplasm might not be necessary. The aquatic moss Hygrohypnum luridum can retain polyribosomal and ribosomal activity during desiccation, but this decreases greatly on rehydration.     

Cyclization of 13beta-ethyl-3-methoxy-17beta-ol-8,14-seco-1,3,5(10),9-gonatetraen-14-one and its 17 acetate derivative.

13beta-Ethyl-3-methoxy-17beta-ol-8,14-seco-1,3,5(10),8-gonatetraen-14-one (IIIa) was isolated and its participation in the well-known acidic cyclization process was established.     

Histochemical localization of capillary enzyme activities in brain smears.

Since the regulation of the vascular permeability in the CNS is dependent partly on the enzymes associated with the wall of brain capillaries, the histochemical demonstration of these enzymes may furnish further data on the function of the blood brain barrier (BBB), a new methodological approach, using brain smears was developed for the histochemical demonstration of several enzymes participating in the function of the BBB. The method presented renders possible also the subsequent demonstration of monoamines and the activity of different enzymes in the same tissue preparation. The usefulness of this simple technique in the study of brain capillary functions is discussed.     

A theory for environmental systems

A theory for environmental systems is defined on the basis of two elements, termed ‘environmental unity’ and ‘behavior’. Environmental systems are regarded as non-living systems, each one related with only one biological system. We construct a material-energetic environmental diagram, which is introduced in terms of the theory of categories, thereby giving rise to a new categoryE. By means of two biological conditions, and the definition of static property of the biological system (related to its own environment), a set of theorems is obtained, exhibiting mathematical consequences for the represented theory.     

Nonrandom distribution of goblet cells around the circumference of colonie crypt

The ascending colon of the guinea pig was cut serially and stained with the periodic-acid-Schiff-hematoxylin method. Maps of transversely sectioned crypts were prepared using a microscopic eye-piece projector. The number and angular positions of goblet cells were mapped around the circumference of transverse sections of the crypt. A method of the "statistics of the circumference" was introduced in order to assess the pattern of distribution of goblet cells. This distribution was found to be significantly nonrandom. The nonrandomness is such that the goblet cells tend to occupy positions of the crypt circumference in maximal distances from each other.     

Partial purification and characterization of two cytoplasmic DNA polymerases from ungerminated wheat.

Two DNA polymerases have been purified from the 105,000 x g supernatant of ungerminated wheat. The purification stages included: high speed centrifugation, salt fractionation, DEAE-cellulose chromatography, Sephadex G-150 filtration and phosphocellulose chromatography. Several properties of the two enzyme (called A and B according to the order of elution from the phosphocellulose column) have been studied. Enzyme A has a sedimentation coefficient of about 7 S, utilizes activated DNA and synthetic polydeoxynucleotides as well as poly rA-dT12, while B has a sedimentation coefficient of about 6.2 and uses only activated DNA and synthetic polydeoxynucleotides as templates. Other parameters like KCl effect, MnCl2 effect, optimum pH, etc. Allow us to distinguish clearly between both DNA polymerases.