Quantification of a decapeptide anticoagulant in rat and monkey plasma by high-performance liquid chromatography

A reversed-phase high-performance liquid chromatographic method was developed to quantify a decapeptide anticoagulant in rat and monkey plasma. The compound and internal standard, a nonapeptide analogue, were extracted from plasma with an amino solid-phase extraction column with an extraction efficiency in the range 75–90%. A C₁₈ analytical column was used to separate the analytes by gradient elution followed by ultraviolet detection at 215 nm. Quantification of the decapeptide over the concentration range 0.1–10.1 μg/ml resulted in an assay relative error and relative standard deviation both less than 10%. The anticoagulant decapeptide was stable in both rat and monkey plasma frozen at −20°C.     

Stage-specific cuticular proteins of Ostertagia circumcincta and Ostertagia ostertagi

In this study we have shown that NHS-biotin and I¹²⁵-streptavidin can detect cuticular polypeptides of Ostertagia spp. The labelled polypeptide profile of intact nematodes is simple compared to the profile obtained by labelling homogenates. None of the major internal polypeptides are labelled and the subset of proteins labelled in intact nematodes appears to be mainly surface associated. The results presented here demonstrate that NHS-biotin may be used as a reagent for the analysis of surface polypeptides. The surface polypeptide profiles of the five major developmental stages (L1, L2, L3, L4 and adult) of Ostertagia circumcincta show a series of stage-specific molecules with no polypeptides common to all stages, indicating that the cuticle is a dynamic structure which changes throughout the life cycle. Similarity comparison of Ostertagia ostertagi L3 and L4 stage surface profiles showed that each stage is clearly distinct; comparison of these stages between the two species shows an overall similarity.     

Vanadium-containing tunicate blood cells are not highly acidic

The intracellular pH of intact blood cells of the tunicate Ascidia nigra was measured by transmembrane equilibration of [¹⁴C]methylamine. The pH of unfractionated blood cells is 7.39±0.10. The pH of vanadocytes, determined in a fractionation study, is 7.2. Previously used methods, in which pH values less than 3.0 are inferred from cell lysis or vital staining experiments, are shown to be unsuitable for intracellular pH determination due to the chemical composition of these vanadium-containing cells.     

Pneumocystis carinii: Freeze-fracture study of stages of the organism

The morphology and life cycle of Pneumocystis carinii were studied in cortico-steroid-treated rats by ultrathin section and freeze-fracture electron microscopy. The following stages of P. carinii were noted: trophic, precyst, and cyst. The crescent-shaped cysts appeared to be intermediate forms between precyst and cyst. The cell wall of the trophic stage showed membrane structures suggestive of protozoan endocytosis, whereas the surface of the precyst stage was smooth. The cell wall of the cyst lacked the specialized structural differentiation of yeasts and resembled that of Plasmodium spp. We conclude that P. carinii belongs to the Protozoa, and is presumably Rhizopoda.     

Induction of congenital anomalies in offspring of female mice exposed to varying doses of X-rays

Female mice were exposed to varying absorbed doses (108–504 rad) of X-rays and mated at different intervals after irradiation (1–7, 8–14, 15–21 and 22–28 days). Uterine contents were examined at late pregnancy in order to detect early fetal deaths (dominant lethality) and malformations in the live fetuses.Two trends were apparent from data on abnormal fetuses. At each weekly interval, the incidence of abnormalities tended to rise with increase in dose, and, at any given dose, the incidence tended to increase with time after irradiation. Dwarfism and exencephaly were the two most common malformations found.The changes in incidence of dominant lethality and of abnormal fetuses with time and with dose follow each other closely, the highest incidence for both being reached in week 3 (59±4.7% for dominant lethals and 12.5±3.1% for abnormal fetuses, after 504 rad) indicating increased radiosensitivity of less mature oocytes. These results parallel those obtained from known genetic effects reported by other workers and suggest that testing for incidence of congenital malformations among offspring of treated animals may prove a useful means of assessing genetic hazards of radiation of chemicals.     

The effect of blue light on free and esterified phenolic acids in etiolated gherkin tissues

The major phenolic acid found in gherkin tissues is p-coumaric acid, although cinnamic and caffeic acids are also present; these occur both free an     

Arrangement of Integrated Avian Sarcoma Virus DNA Sequences Within the Cellular Genomes of Transformed and Revertant Mammalian Cells

We have examined the arrangement of integrated avian sarcoma virus (ASV) DNA sequences in several different avian sarcoma virus transformed mammalian cell lines, in independently isolated clones of avian sarcoma virus transformed rat liver cells, and in morphologically normal revertants of avian sarcoma virus transformed rat embryo cells. By using restriction endonuclease digestion, agarose gel electrophoresis, Southern blotting, and hybridization with labeled avian sarcoma virus complementary DNA probes, we have compared the restriction enzyme cleavage maps of integrated viral DNA and adjacent cellular DNA sequences in four different mouse and rat cell lines transformed with either Bratislava 77 or Schmidt-Ruppin strains of avian sarcoma virus. The results of these experiments indicated that the integrated viral DNA resided at a different site within the host cell genome in each transformed cell line. A similar analysis of several independently derived clones of Schmidt-Ruppin transformed rat liver cells also revealed that each clone contained a unique cellular site for the integration of proviral DNA. Examination of several morphologically normal revertants and spontaneous retransformants of Schmidt-Ruppin transformed rat embryo cells revealed that the internal arrangement and cellular integration site of viral DNA sequences was identical with that of the transformed parent cell line. The loss of the transformed phenotype in these revertant cell lines, therefore, does not appear to be the result of rearrangement or deletions either within the viral genome or in adjacent cellular DNA sequences. The data presented support a model for ASV proviral DNA integration in which recombination can occur at multiple sites within the mammalian cell genome. The integration and maintenance of at least one complete copy of the viral genome appear to be required for continuous expression of the transformed phenotype in mammalian cells.     

Fate of the theca interna following ovulation in the ewe

Summary The fate of the theca interna after ovulation was studied in ewes, using light and electron microscopic histology and histochemistry. At the time of ovulation the theca interna was incorporated, apparently completely, into the margin of the developing corpus luteum and into the centres of many infoldings of the follicular wall. There was no evidence of degeneration of the more highly differentiated theca interna cells at or following the time of ovulation. Within 24 h of ovulation, cells derived from the theca interna began migrating from their original sites into the deeper, granulosa-derived areas of the luteal tissue. At later stages cells derived from the theca interna remained concentrated in septa derived from the follicular infoldings, but were also widely distributed throughout the luteal tissue. Structural evidence supported the view that the small luteal cells and fibroblasts of the corpus luteum were derived from the theca interna, and the large luteal cells from the membrana granulosa.The authors wish to thank Mrs. Linda Musk and Miss Anneke Veenstra for skilled technical assistanceDeceased on May 4, 1979     

Comparative evaluation of macrophage stimulation and depression on tumor growth and macrophage content and function in mice

Summary In a syngeneic murine adenocarcinoma model, the administration of glucan, an RE stimulant, inhibited tumor growth and increased tumor macrophage populations. Conversely, the administration of methyl palmitate, an RE depressant, potentiated tumor growth and decreased the number of tumor macrophages. Glucan and methyl palmitate also produced diverse alterations in serum lysozyme levels that reflected their contrasting influences on RE functional status, thus supporting the role of serum lysozyme as an index of macrophage function. The diverse results produced by macrophage stimulation or depression in regard to tumor growth, tumor macrophage population, and serum lysozyme concentration indicate that a relationship may exist between macrophage functional activity and host resistance to neoplasia.