New labdane resin acids from Pinus elliottii

Slash pine needles and cortex oleoresin have been found to contain a new major diterpene constituent, imbricataloic acid. The closely related imbricatoloic acid, previously reported only in Araucaria imbricata, was found to be present in small amounts in slash pine needle extract. Spectral data are given for an unidentified diterpene alcohol isolated from the cortex oleoresin.     

Studies on ulcerative dermal necrosis of salmonids

Fourteen fresh run salmon Satmo salar L. with early extant lesions of ulcerative dermal necrosis (UDN) were kept in separate tanks and treated with zinc free malachite green. Ten of the fish were held at 10° C and 4 at 2° C. The treatment precluded infection with Saprolegnia fungus and allowed natural resolution of the lesions. There was a marked difference in rate of healing between warm and cold water conditions.
Histological examination of healing lesions at different stages showed that there was a primary invasion of cuboidal epithelium over the collagen scar followed by a phase of disorganized proliferation which eventually organized itself into normal epithelium. Melanocytes were very obvious in the dermis of healing lesions.     

Epilogue — Demography and anthropology

As a conclusion, this paper reviews briefly the content of the volume. The wealth of demographic data has not been adequately exploited in anthropology; this is why this publication is valuable in showing attempts to apply demographic data in a variety of anthropological problems. This symposium has explored many interesting points which we recall here. Yet it has also opened up a whole range of further questions on the material presented as well as in this broad field. Several directions of research could be developed, for instance, testing among human populations, over long periods, the ecological thoughts of ecosystems evolving as a cascade of instabilities, rather than a succession of equilibrium states. Let us also recall the pervasive nature of demographic facts in topics such as the energy cycle or the genetic structure and evolution of human populations.     

500-MHz 1H NMR studies of ragweed allergen Ra5

The solution conformation of short ragweed allergen Ra5, a protein of 45 amino acid residues cross-linked with four disulfide bridges, has been investigated by 1H NMR spectroscopy at 500 MHz. The aromatic region, which contains resonances from three tyrosines and two tryptophans, has been partially assigned. Two tyrosines titrate with a pK of 10.2; a third tyrosine is buried under the tryptophan resonances, and its pK could not be determined. The two tryptophans reside in different microenvironments; the resonances of one are very similar to those found in random coil structures while the other has dramatically shifted peaks. Nuclear Overhauser effect (NOE) difference spectroscopy is used to define two distinct spin-diffusion systems for the aromatic residues and to further identify several methyl-containing amino acids involved in these systems. Assignments in the methyl region are based on selective decoupling, chemical shifts, NOE difference spectra, and 2-D J-resolved and 2-D J-correlated spectroscopy (COSY) methodology. A unique ring-current-shifted methyl doublet in the Ra5 spectrum titrates into the bulk methyl region with a pK of 10.2. Examination of the COSY map suggests that this resonance belongs to either leucine-1 or isoleucine-38. Chemical removal of the N-terminal leucine did not affect the ring-current-shifted methyl. Therefore, this unique resonance has been assigned to the methyl of isoleucine-38.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effector mechanisms in allograft rejection. IV. In contrast to late cytotoxic cells, and early killer cells infiltrating mouse sponge matrix allografts are predominantly T lymphocytes.

We have earlier demonstrated that a mixed population of immunologically specific killer cells, including cytotoxic T lymphocytes, non-T (“B”) lymphocytes and monocytes, infiltrate “sponge matrix” allografts at the peak of rejection on Day 8 after transplantation. We have now performed a sequential study covering both early and late stages of the rejection response. We demonstrate that the early infiltrating killer cells are sensitive to anti-Ø and anti-T cell serum plus complement treatment but the late killer cells are not. This finding indicates that the first cytotoxic host cells infiltrating the allograft are predominantly T lymphocytes, whereas as the rejection process proceeds also cytotoxic non-T (“B”) lymphocytes and monocytes are recruited to the site of inflammation.     

Nitrogenase activity,hydrogen evolution and biomass production in different Casuarina symbioses

Nitrogenase activity, hydrogen evolution, biomass production and nodulation were studied in threeCasuarina species,C. equisetifolia Forst.,C. glauca Sieber ex Spreng andC. obesa Miq., either inoculated with a crushed nodule inoculum prepared fromC. glauca nodules or inoculated with the pure cultureHFP CcI3. Nodulation was also studied inC. cristata Miq. inoculated with the above mentionedFrankia sources. C. equisetifolia, C. glauca andC. obesa were nodulated when inoculated with both of theFrankia inoculum, whileC. cristata was very poorly nodulated. Nitrogenase activity per plant and on a nodule dry weight basis was significantly highest inC. glauca inoculated withC. glauca inoculum after 150 days from planting. This difference decreased and at 217 days from planting there was no significant difference between the symbioses, except forC. obesa inoculated withC. glauca inoculum which showed the significantly lowest nitrogenase activity. After 150 days from planting relative efficiency of nitrogenase was lowest inC. equisetifolia inoculated withHFP CcI3 and inC. equisetifolia inoculated withC. glauca inoculum. Biomass production was similar inC. glauca inoculated withC. glauca inoculum, inC. equisetifolia inoculated withHFP CcI3 and inC. obesa inoculated withHFP CcI3 at the final harvest. The data presented here show that there is a strong interrelationship between host plant and endobiont. This interrelationship is of considerable importance when introducing Casuarina symbioses for production of fuel wood.     

Analysis of fidelity mechanisms with eukaryotic DNA replication and repair proteins

We are investigating the mechanisms for producing or avoiding errors during DNA synthesis catalyzed by DNA replication and repair proteins purified from eukaryotic sources. Using assays that monitor the fidelity of a single round of DNA synthesis in vitro, we have defined the error frequency and mutational specificity of the four classes of animal cell DNA polymerases (alpha, beta, delta, gamma), and the fidelity of an SV40 origin-dependent DNA replication complex in extracts of HeLa cells.