Synthesis and evaluation of Triticum durum — T. monococcum amphiploids

Summary Nine Triticum durum — T. monococcum amphiploids (AABBA^mA^m) were synthesized by chromosome doubling of sterile triploid F₁ hybrids involving nine T. durum (AABB) cultivars and a T. monococcum (A^mA^m) line. The triploid F₁ hybrids had a range of 4–7 bivalents and 7–13 univalents per PMC. The synthetic amphiploids, however, showed a high degree of preferential pairing of chromosomes of the A genomes of diploid and tetraploid wheats. The amphiploids were meiotically stable and fully fertile. Superiority of four amphiploids for tiller number per plant, 100-grain weight, protein content and resistance to Karnal bunt demonstrated that these could either be commercially exploited as such after overcoming certain inherent defects or used to introgress desirable genes into durum and bread wheat cultivars. Methods for improvement of these amphiploids are discussed.     

The group-specific protein marker: a possible indicator of syphilis,not human immunodeficiency virus infection.

We wished to compare the frequency of group-specific (Gc) phenotypes in the general population with that in people with human immunodeficiency virus (HIV) infection to find out whether the Gc protein is a marker for susceptibility to HIV infection. We determined the phenotype frequency in 1083 randomly selected serum samples obtained from the Canadian Influenza Survey Studies and compared it with that in 263 serum samples obtained from the Federal Centre for AIDS and the Syphilis Serology Proficiency Testing Laboratory. No association between Gc phenotype and HIV status was found. However, there was a strong association between the Gc protein 1f/1f phenotype and syphilis.     

Variability in vibration perception threshold among sites: a potential source of error in biothesiometry

Vibration perception threshold was measured with a biothesiometer by a single observer at both medial malleoli and both big toes in 110 diabetic patients aged 15-65 selected at random and in 64 non-diabetic subjects aged 20-65. The vibration perception threshold showed appreciable individual variation both between contralateral sites and between ipsilateral sites, differing by at least 30% between the big toes in 26 (24%) of the diabetic patients and 16 (25%) of the non-diabetic group. Variability between sites was significantly greater in the diabetics than the normal subjects. The vibration perception threshold exceeded published normal values at one or more sites in 22 of the diabetic patients but at all four sites in only four.The wide variability in vibration perception threshold among sites may be due to the tissue characteristics locally and, in diabetic patients, possibly to asymmetric neuropathy. Biothesiometer readings at single or unilateral sites may be unrepresentative or misleading.     

Atomic force microscopy examination of the topography of a hydrated bacterial biofilm on a copper surface

A bacterium, designated CCI#8, that was isolated from a corroded copper coupon colonized both polished and unpolished copper surfaces under batch culture conditions. Atomic Force Microscopy (AFM) images revealed that the biofilm was heterogeneous in nature, both in depth and in cell distribution. Bacterial cells were shown to be associated with pits on the surface of the unpolished copper coupons. These observations support previous studies that CCI#8 is associated with the pitting corrosion of copper.     

Substituted piperidin-2-one biphenyltetrazoles as angiotensin II antagonists

A novel series of substituted piperidine-2-ones has been identified as antagonists of angiotensin II. These compounds showed high affinity for the receptor in bovine adrenal cortex binding assays with IC₅₀'s as low as 20nM. They are potent inhibitors of angiotensin II induced contractions in rabbit aortic rings, with pA₂ values as high as 9. A number of these compounds are also orally active as antihypertensives in spontaneously hypertensive rat preparations.     

Attempted Transformation of Wheat (Triticum aestivum) and Tobacco (Nicotiana tabacum) by Plasmid DNA Uptake Via the Pollen-tube Pathway

Plasmid DNA (CaMVGUS, containing β-glucuronldase gene) was used to transform developing seed of wheat and tobacco through pollen-tube pathway. The DNA was applied on the ovule end of excised styles and stigmas of wheat and tobacco after pollination. None of the 272 wheat and 13,567 tobacco plants obtained after application of the isolated DNA showed β-glucuronidase activity suggesting that the pollen-tube pathway may not be effective for transformation of plants.     

Isolation of additional monoclonal antibodies directed against cell surface antigens of Myxococcus xanthus cells undergoing submerged development.

Thirteen additional monoclonal antibodies directed against cell surface antigens of Myxococcus xanthus cells undergoing submerged development were isolated and partially characterized. As measured by quantitative enzyme-linked immunosorbent assay, 10 of these antibodies recognized antigens common to both vegetatively growing cells and cells undergoing submerged development; 3 antibodies recognized antigens specific to developing cells. Five antigens were revealed as single bands on Western blots (immunoblots), and one produced multiple, diffuse bands characteristic of lipopolysaccharide.     

Histochemical characterization of myotomal muscle in the grass pickerel, Esox americanus vermiculatus (LeSeuer), and the muskellunge, E. masquinongy (Mitchell)

A histochemical study of the myotomal muscles in the grass pickerel, Esox americanus vermiculatus , and the muskellunge, E. masquinongy , was performed using actomyosin ATPase and NADH diaphorase activities. Three fibre types, i.e., red, white and pink were distinguished on the basis of their enzyme activities. White muscle fibres comprised the bulk of the myotomal musculature. The relative proportion of red muscle fibres was greater in the caudal region than in more anterior regions of the body. Pink fibres formed only a few layers between red and white. These findings are discussed in relation to the possible functional significance of the muscle fibre types in swimming and feeding behaviour in these species.     

Influence of inositol 1,4,5-trisphosphate and guanine nucleotides on intracellular calcium release within the N1E-115 neuronal cell line

The Ca2+ accumulating properties of a nonmitochondrial intracellular organelle within cultured N1E-115 neuroblastoma cells containing an (ATP + Mg2+)-dependent Ca2+ pump were recently described in detail (Gill, D. L., and Chueh, S. H. (1985) J. Biol. Chem. 260, 9289-9297). Using both saponin-permeabilized N1E-115 cells and microsomal membranes from cells, this report describes the effectiveness of both inositol 1,4,5-trisphosphate (IP3) and guanine nucleotides in mediating Ca2+ release from this internal organelle, believed to be endoplasmic reticulum. Using permeabilized N1E-115 cells, 2 microM IP3 effects rapid release (t1/2 less than 20 s) of approximately 40% of accumulated Ca2+ releasable with 5 microM A23187. Half-maximal Ca2+ release occurs with 0.5 microM IP3, and maximal release with 3 microM IP3. Using a frozen microsomal membrane fraction isolated from lysed cells, 2 microM IP3 rapidly releases (t1/2 less than 30 s) 10-20% of A23187-releasable Ca2+ accumulated within nonmitochondrial Ca2+-pumping vesicles, although only in the presence of 3% polyethylene glycol (PEG). 10 microM GTP, but not guanosine 5'-(beta, gamma-imido)triphosphate (GMPPNP), increases the extent of release in the presence of IP3. Importantly, however, GTP alone induces a substantial release of Ca2+ (up to 40% of releasable Ca2+) with a t1/2 value (60-90 s) slightly longer than that for IP3. The effects of IP3 and GTP are approximately additive, and both effects require 3% PEG. Half-maximal Ca2+ release occurs with 1 microM GTP, with maximal release at 3-5 microM GTP; 20 microM GMPPNP has no effect on release and only slightly inhibits 5 microM GTP; 20 microM GDP promotes full release, but only after a 90-s lag, and initially inhibits the action of 5 microM GTP. Using permeabilized N1E-115 cells, 5 microM GTP with 3% PEG releases greater than 50% of releasable Ca2+; without PEG, GTP still mediates approximately 30% release of Ca2+ from cells. Neither IP3, GTP, or both together (with or without PEG) effects release of Ca2+ accumulated within synaptic plasma membrane vesicles. The profound effectiveness of GTP on Ca2+ release has important implications for intracellular Ca2+ regulation and is probably related to Ca2+ release mediated by IP3.