Congenital Dislocation of the Hip: Prognostic Implications of Early Diagnosis

A retrospective analysis of 62 patients with 78 congenital dislocations of the hip (CDH) referred to Children''s Hospital at Stanford was done to ascertain whether CDH was being diagnosed as early as had been thought possible and whether various treatments were effective. In this series there were a substantial number of cases of CDH that were not diagnosed within the first 48 hours of life. At Children''s Hospital the Pavlik harness was the most effective form of treatment of congenital dislocations of the hip in the perinatal period.     

Systematic studies of Pinus balfouriana based on volatile terpenoids from wood and needles and on seed morphology

Essential oil from wood and from needles of Pinus balfouriana, growing in six geographically well-separated locations in California, was analysed by GLC. Several monoterpenoid components, in particular -pinene from needles, were found to be usable for distinguishing between trees from the northern and southern parts of the geographic range. Similarity coefficients were calculated and dendrograms constructed. These demonstrated the distinct separation of the northern from the southern populations, and thus substantiated the proposal by Mastrogiuseppe to regard the southern populations as a subspecies. While the northern populations exhibited a tendency to produce larger seeds with longer wings, the difference was of only moderate diagnostic value.     

Membrane surface properties of sheep erythrocytes,an immunological reagent,after different treatments as reflected by partition in two-polymer aqueous phases

Sheep erythrocytes (E) which, with or without certain treatments, are currently used as “immunological reagents” to detect cells with specific receptors (by rosette-formation) have been partitioned in two-polymer aqueousphase systems selected so as to reflect charge-associatedor lipid-related membrane surface properties. We have found that the partitioning behavior of E is not affected in these phases by reacting the cells with anti-E antibody (either IgG or IgM), forming EA. The additional binding of complement to the cell-antibody complex, forming EAC, results, however, in a marked decrease in the partition coefficient,K. Apparently both the charge-associated and hydrophobic properties reflected by partitioning remain accessible to the phase polymers when the cells are coated with antibody, but are not with the addition of complement. It is interesting that EA can still rosette with T-lymphocytes (14), a property of E, while the additional coating with complement results in EAC which does not appreciably do so (26). Neuraminidase or trypsin treatments of E, which yield Es having quite different rosetting properties with T-lymphocytes (14), cause increasedKs and unchangedKs, respectively, in phases reflecting lipid-related surface properties. Either treatment causes reducedKs of E in charged-phase systems. Neuraminidase treatment also results in a reduced electrophoretic mobility of E, while trypsin treatment is not detectable by cell electrophoresis (25). We are currently studying the possible usefulness of employing cell electrophoresis and cell partitioning in charged-phase systems jointly to obtain information on events occurring at the shear plane versus those occurring deeper in the membrane.     

Biosynthesis of sesquiterpenes in Hymenaea inferred from their quantitative co-occurrence

Leaf pocket resins of 11 species of the tropical arborescent genus Hymenaea are virtually identical qualitatively, but of widely varying quantitative proportions. Within this large range of variability, several strong positive quantitative correlations between resin constituents were found, especially between caryophyllene and β-humulene and between γ-muurolene and δ-cadinene. These data lead to clarification of sesquiterpene biosynthetic routes in Hymenaea. In addition, quantitative relationships found among caryophyllene, α- and β-selinene, γ-muurolene and δ-cadinene are explained only with difficulty by long accepted biosynthetic pathways, and the intermediacy of germacrenes is suggested.     

Partial characterization of prostaglandin synthetase in the reproductive tract of the male house cricket, acheta domesticus

An active prostaglandin (PG) synthetase was found in the 12100 g pellet of reproductive tract homogenates of the male house cricket, $\text{Acheta domesticus}$. Comparatively, the 12100 g supernatant and the microsomal fractions were inactive. The PG synthetase in the pellet fraction was characterized in terms of cofactor, temperature, pH, and incubation time requirements. Indomethacin, a known inhibitor of mammalian PG synthetase, was not inhibitory to the cricket synthetase. The procedure and findings are relevant to PG synthetase studies of any organism or tissue.     

Oxygen consumption of human blood platelets. II. Effect of inhibitors on thrombin-induced oxygen burst

The effect of selected inhibitors on the thrombin-stimulated burst and the basal oxygen consumption of washed human platelets were investigated and compared with inhibition of the release reaction. Cyanide (0.2 mM) caused complete inhibition of the basal respiration, but only 15% inhibition of the thrombin-stimulated burst of oxygen consumption. Similar differential inhibitory effects were observed with oligomycin, antimycin, rotenone and N-ethylmaleimide. Prostaglandin E₁ (0.03 mM) and acetylsalicylic acid (0.8 mM) had little effect on basal respiration, but inhibited the thrombin-stimulated burst of oxygen consumption. N-Ethylmaleimide (0.4 mM) inhibited the release of calcium from platelets by 90%, while prostaglandin E₁, acetylsalicylic acid and the above mitochondrial inhibitors caused no more than 30% inhibition of the release reaction. Our results provide evidence that basal respiration and a portion of the thrombin-stimulated burst of oxygen consumption are involved in respiratory chain phosphorylation, and that this component of the thrombin-stimulated burst may be coupled to the maintenance of the release reaction.     

On the effect of mechanical shocks on the congelation of subcooled plant tissues

Summary Cylindrical shells of potato tissue were slid around the bulb of a thermometer and subcooled. Attempt was then made to induce crystallization by tapping the upper end of the thermometer. Out of 122 trials 52 were successful. In a few experiments, 15 repeated taps were ineffective. There is absolute evidence of the efficacy of tapping in some cases and of its inefficacy in others.The percentage of successful tappings increases at lower temperatures but since the percentage of spontaneous crystallizations also increases, a much larger number of determinations would be necessary to derive a relation between degree of subcooling and efficacy of tapping.No evidence was found in these experiments of the existence of discontinuous zones of lability at various degrees of subcooling.     

Protein-Protein Interactions in the β-Oxidation Part of the Phenylacetate Utilization Pathway: CRYSTAL STRUCTURE OF THE PaaF-PaaG HYDRATASE-ISOMERASE COMPLEX*

Microbial anaerobic and so-called hybrid pathways for degradation of aromatic compounds contain β-oxidation-like steps. These reactions convert the product of the opening of the aromatic ring to common metabolites. The hybrid phenylacetate degradation pathway is encoded in Escherichia coli by the paa operon containing genes for 10 enzymes. Previously, we have analyzed protein-protein interactions among the enzymes catalyzing the initial oxidation steps in the paa pathway (Grishin, A. M., Ajamian, E., Tao, L., Zhang, L., Menard, R., and Cygler, M. (2011) J. Biol. Chem. 286, 10735–10743). Here we report characterization of interactions between the remaining enzymes of this pathway and show another stable complex, PaaFG, an enoyl-CoA hydratase and enoyl-Coa isomerase, both belonging to the crotonase superfamily. These steps are biochemically similar to the well studied fatty acid β-oxidation, which can be catalyzed by individual monofunctional enzymes, multifunctional enzymes comprising several domains, or enzymatic complexes such as the bacterial fatty acid β-oxidation complex. We have determined the structure of the PaaFG complex and determined that although individually PaaF and PaaG are similar to enzymes from the fatty acid β-oxidation pathway, the structure of the complex is dissimilar from bacterial fatty acid β-oxidation complexes. The PaaFG complex has a four-layered structure composed of homotrimeric discs of PaaF and PaaG. The active sites of PaaF and PaaG are adapted to accept the intermediary components of the Paa pathway, different from those of the fatty acid β-oxidation. The association of PaaF and PaaG into a stable complex might serve to speed up the steps of the pathway following the conversion of phenylacetyl-CoA to a toxic and unstable epoxide-CoA by PaaABCE monooxygenase.