Purification of restriction endonuclease XcyI from Xanthomonas cyanopsidis

A new Type II restriction endonuclease XcyI, purified from Xanthomonas cyanopsidis 13D5, is an isoschizomer of SmaI and XmaI that cleaves at the nucleotide sequence 5'-C decreases CCGGG-3' of double-stranded DNA. The single restriction activity present in this strain permits rapid purification of 8000 units of cleavage activity from 10 g of freshly harvested cells. The resulting XcyI preparation is free of contaminating nuclease activities that interfere with in vitro manipulation of DNA.     

Pathogenicity of Macroposthonia xenoplax to Walnut

Preplanting treatment of soil naturally infested with Macroposthonia xenoplax with 1,2-dibromoethane (ethylene dibromide) significantly increased the growth rate of Juglans hindsii seedlings. When seedlings of J. hindsii, J. regia CV "Serf" and J. regia CV Eureka were inoculated with M. xenoplax, their growth was signilicantly less than that of nematode-free controls. This retarded growth rate was accompanied hy feeder root necrosis, longitudinal cracks in the older roots, and distinct lesions in the secondary phloem.     

The adenylate cyclase-activating activity of cholera toxin is not associated with a nicotinamide--adenine dinucleotide glycohydrolase activity.

The NAD+ glycohydrolase activity of cholera-toxin samples can be separated from their adenylate cyclase-activating activity by polyacrylamide-gel electrophoresis and is inhibited by sodium dodecyl sulphate (which does not inhibit the action of toxin on cells), but not by antibodies to pure toxin. It is therefore probably not a true property of the toxin.     

HLA patterns in pernicious anaemia.

The pattern of HLA antigens was studied in 127 patients with Addisonian pernicious anaemia. The pattern in the whole group of patients differed significantly from that in 586 controls. But different subgroups of the patients had different HLA antigens. Among 27 patients with anaemia associated with endocrine disease there was an increased frequency of HLA-B8, B18, and BW15. The remaining 100 patients, who did not have endocrine disease, showed increased frequencies of HLA-B7 and B12. The positive association with HLA-B12 among this subgroup was confined to 62 patients with severly impaired vitamin B12 absorption, including 13 patients with vitamin B12 neuromyelopathy, who had the highest frequencies of HLA-B7 and B12. The significant heterogeneity in HLA patterns in different clinical subgroups of these patients indicates genetic heterogeneity in pernicious anaemia and explains previous discrepancies in the associations between HLA antigens and pernicious anaemia.     

The Microaerophile SPirillum volutans: Cultivation on Complex Liquid and Solid Media

Spirillum volutans grows only under microaerobic conditions in a peptone-succinate-salts broth, but can grow aerobically when the peptone is replaced by vitamin-free acid-hydrolyzed casein broth. The addition of potassium metabisulfite, norepinephrine, catalase or superoxide dismutase (SOD) permitted aerobic growth in peptone-succinate-salts broth. A combination of catalase and SOD had a synergistic effect. S. volutans lacked catalase and had only a low level of peroxidase activity, but did possess SOD activity (12 to 14 U/mg of protein). The organism was found to be extraordinarily sensitive to exogenous hydrogen peroxide. Illumination of peptone-succinate-salts broth generated hydrogen peroxide and rendered the medium inhibitory to growth. A combination of catalase and SOD prevented this inhibition. Growth of S. volutans on solid media, not previously possible, was accomplished by the use of vitamin-free acid-hydrolyzed casein and peptone-succinate-salts agar media; maximum growth responses were dependent on the following combination of factors: addition of bisulfite, catalase, or SOD, protection of the media from illumination, incubation in a highly humid atmosphere, and incubation under atmospheres of 12% oxygen or less. The results indicate that the microaerophilic nature of S. volutans is attributable largely to the high sensitivity of the organism to exogenous hydrogen peroxide and, to a lesser extent, superoxide radicals occurring in the culture medium.     

Comparative study of the cellular replication kinetics of rat mammary epithelial cells in vivo and in vitro

Ts-131b, one of the temperature-sensitive (ts) mutants isolated from mouse FM3A cells, was found to be defective in DNA replication at a non-permissive temperature. After the cells were transferred to 39.5 °C, the cell number increased by only 10% and the rate of incorporation of precursors into cellular DNA decreased rapidly. Cell cycle analysis by a flow cytometric method with the cells incubated at 39.5 °C revealed that progression of the cells through the S phase was inhibited and most of the cells were arrested in the S phase. To study the defect in DNA replication of this ts-mutant at 39.5 °C, DNA-fiber autoradiography was performed to measure the rate of DNA-chain elongation. The results showed that the rate of DNA-chain elongation was decreased at 6 h after the temperature shift. However, since the decrease in the rate of DNA-chain elongation was not sufficient to account for the decrease in the rate of incorporation of the precursors, it was suggested that there was also a decrease in the rate of initiation of DNA replication at some of the replicon origins.     

Two new species of Viola (Violaceae) from the Intermountain West,U.S.A.

Viola lithion andV. franksmithii are rock-dwelling endemics that belong to the North American perennial, caulescent, simple-leaved, blue-, purple-, or white-flowered group of species.Viola lithion, from the White Pine and Pilot mountain ranges of eastern Nevada and adjacent Utah, belongs to sectionChamaemelanium subsectionCanadenses. It most closely resembles the reniform-leaved, Olympic MountainV. flettii, together with which it possibly shares an ancestry with the widespread and allopatricV. canadensis. Viola franksmithii, restricted to the Logan Canyon drainage of the Bear River Range in northern Utah, belongs to sectionRostellatae subsectionRosulantes. It comes closest morphologically toV. howellii of the Coast Range, but likely evolved from the widespreadV. adunca or a common ancestor.     

Demonstration of a heterogeneous transcription pattern of thyroglobulin mRNA in human thyroid tissues.

Previous reports on human thyroglobulin (hTg) modifications in thyroid carcinomas prompted us to study hTg mRNA in thyroid adenomas and carcinomas. The quantification of hTg mRNA showed a decrease in its levels of expression in both pathological conditions which differed by a factor of 2 between adenomas and carcinomas. Furthermore, PCR was used to analyse the characteristics of hTg mRNA by amplifying 4 regions of the hTg mRNA. When applied to 2 normal, 17 benign and 13 malignant pathological tissue specimens, PCR showed no modification in the size of Tg mRNA. However, abnormal sized cDNAs appeared in all tissues with no distinction between the pathologies; the Restriction Fragment Length Polymorphism study of these cDNAs suggests the existence of alternate splicing patterns in thyroglobulin mRNAs.     

Chromosomal localization of the human annexin III (ANX3) gene

The annexins or lipocortins are a new family of calcium-dependent phospholipid-binding proteins. Annexin III has been previously identified as inositol 1,2-cyclic phosphate 2-phosphohydrolase (EC 3.1.4.36), an enzyme of inositol phosphate metabolism, and also as placental anticoagulant protein III, lipocortin III, calcimedin 35-alpha, and an abundant neutrophil cytoplasmic protein. In this study, the gene (ANX3) encoding annexin III was localized to human chromosome 4 at band q21 (q13-q22) by (1) polymerase chain reaction analysis of a human-rodent hybrid cell panel, confirmed by genomic Southern blot analysis of the same panel with a cDNA probe and (2) in situ hybridization with a cDNA probe.