Exchange systems and style in the Central Mediterranean. 4500-1700 b.c..:Unpublished PhD. Cambridge University Library

Malone, C.A.T., 1986, Unpublished PhD, Cambridge University, Cambridge.

Human B cell colony growth from pre-B cells in vitro

We describe a simple one-step technique for the growth of human B cell colonies in semi-solid agar in vitro. This method used conditioned medium from the human plasmacytoma cell line LICR-LON-H My 2 as a source of stimulating activity. A linear relationship exists between the number of B cells seeded and the number of colonies formed (r = 0.95). Most colony forming cells, approximately 1 in 500 of B cells seeded, lack surface immunoglobulin, possess Fc receptors and mark with the Leu 12 monoclonal antibody. Cells within developing colonies are found to have cytoplasmic IgM, IgA and IgG depending on the length of time in culture.

Regulation of TGF-β1-Driven Differentiation of Human Lung Fibroblasts: Emerging Roles of Cathepsin B and Cystatin C

Lung matrix homeostasis partly depends on the fine regulation of proteolytic activities. We examined the expression of human cysteine cathepsins (Cats) and their relative contribution to TGF-β1-induced fibroblast differentiation into myofibroblasts. Assays were conducted using both primary fibroblasts obtained from patients with idiopathic pulmonary fibrosis (IPF) and human lung CCD-19Lu fibroblasts. Pharmacological inhibition and genetic silencing of Cat B diminished α-smooth muscle actin expression, delayed fibroblast differentiation and led to an accumulation of intracellular 50-kDa TGF-β1. Moreover addition of Cat B generated 25-kDa mature form of TGF-β1 in Cat B siRNA-pretreated lysates. Inhibition of Cat B decreased Smad 2/3 phosphorylation, but had no effect on p38 MAPK and JNK phosphorylation indicating that Cat B mostly disturbs TGF-β1-driven canonical Smad signaling pathway. While mRNA expression of cystatin C was stable, its secretion, which was inhibited by brefeldin A, increased during TGF-β1-induced differentiation of IPF and CCD-19Lu fibroblasts. In addition cystatin C participated in the control of extracellular Cats, since its gene silencing restored their proteolytic activities. These data support the notion that Cat B participates in lung myofibrogenesis as suggested for stellate cells during liver fibrosis. Moreover, we propose that TGF-β1 promotes fibrosis by driving the effective cystatin C-dependent inhibition of extracellular matrix-degrading Cats.

Interpreting A-level Mathematics grades – as easy as A, B, C?

Many concerns have been expressed that students’ basic mathematical skills have deteriorated during the 1990s and there has been disquiet that current A-level grading does not distinguish adequately between the more able students. This study reports the author’s experiences of teaching maths to large classes of first-year engineering students and aims to enhance understanding of levels of mathematical competence in more recent years. Over the last four years, the classes have consisted of a very large proportion of highly qualified students – about 91% of them had at least grade B in A-level Mathematics. With a small group of students having followed a non-traditional route to university (no A-level maths) and another group having benefitted through taking A-level Further Mathematics at school, the classes have contained a very wide range of mathematical backgrounds. Despite the introductory maths course at university involving mainly repetition of A-level material, students’ marks were spread over a very wide range – for example, A-level Mathematics grade B students have scored across the range 16 – 97%. Analytical integration is the topic which produced the largest variation in performance across the class but, in contrast, the A-level students generally performed well in differentiation. Initial analysis suggests some stability in recent years in the mathematical proficiency of students with a particular A-level Mathematics grade. Allowing choice of applied maths modules as part of the A-level maths qualification increases the variety of students’ mathematical backgrounds and their selection from mechanics, statistics or decision maths is not clear from the final qualification.

Asymmetric Total Synthesis of (+)-Inthomycin C Via O-Directed Free Radical Alkyne Hydrostannation with Ph3SnH and Catalytic Et3B: Reinstatement of the Zeeck-Taylor (3R)-Structure for (+)-Inthomycin C

A new pathway to (+)-inthomycin C is reported that exploits an O-directed free radical hydrostannation reaction on (−)-12 and a Stille cross-coupling as key steps. Significantly, the latter process was effected on 19 where a gauche-pentane repulsive interaction could interfere. Our stereochemical studies on the alkynol (−)-12 and the enyne (+)-7 confirm that Ryu and Hatakeyama’s (3S)-stereochemical revision of (+)-inthomycin C is invalid and that Zeeck and Taylor’s original (3R)-stereostructure for (+)-inthomycin C is correct.

Synthesis of the C(7)-C(22)-Sector of (+)-Acutiphycin Via O-Directed Double Free Radical Alkyne Hydrostannation with Ph3SnH/Et3B, Double I-Sn Exchange and Double Stille Coupling

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Herein a new double O-directed free radical hydrostannation reaction is reported on the structurally complex dialkyldiyne 11. Through our use of a conformation-restraining acetal to help prevent stereocenter-compromising 1,5-H-atom abstraction reactions by vinyl radical intermediates, the two vinylstannanes of 10 were concurrently constructed with high stereocontrol using Ph3SnH/Et3B/O2. Distannane 10 was thereafter elaborated into the bis-vinyl iodide 9 via O-silylation and double I–Sn exchange; double Stille coupling of 9, O-desilylation, and oxidation thereafter furnished 8.

Effect of ultraviolet-B light on lymphocyte activity at doses at which normal bone marrow stem cells are preserved

Ultraviolet B (UVB) light is known to be immunosuppressive, but, probably because of a small UVC component in the emission spectra of some of the UVB lamps used, reports vary on effective dose levels. To prevent potentially lethal graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation, alloreactive donor T-cell activity must be suppressed. In this study, a narrow wavelength UVB lamp (TL01, 312 nm peak emission) was used to determine what doses of UVB were required to abolish rat lymphocyte proliferation while simultaneously preserving rat bone marrow progenitor cell and primitive hematopoietic stem cell viability. Lymphocyte proliferation, as measured by 3H-Thymidine incorporation, in response to lectin stimulation was abolished below detection at doses greater than 3,500 J/m2. When T-cell clonogenicity was measured in a limiting dilution assay, a small fraction (0.6%) was maintained at doses up to 4,000 J/m2. Cytotoxic T-lymphocyte (CTL) activity was reduced after treatment with 4,000 J/m2, but a significant level of cytotoxicity was still maintained. Natural killer cell cytolytic activity was not affected by doses up to 4,000 J/m2. At 4,000 J+m2 there was a 10% survival of colony-forming units-granulocyte-macrophage; a 1% and 4% survival of day-8 and day-12 colony-forming units-spleen, respectively; and 11% survival of marrow repopulating ability cells. Up to 25% of late cobblestone area forming cells (4 to 5 weeks), reflecting the more immature hematopoietic stem cells, were preserved in bone marrow treated with 4,000 J/m2, indicating that early stem cells are less sensitive to UVB damage than are more committed progenitor cells. Thus, a potential therapeutic window was established at approximately 4,000 J/m2 using this light source, whereby the potentially GVHD-inducing T cells were suppressed, but a sufficient proportion of the cells responsible for engraftment was maintained.

The effect of pantethine and ultraviolet-B radiation on the development of lenticular opacity in the emory mouse.

PURPOSE: Few studies have examined the impact of long-term treatments or exposures on the development of cataract in maturity-onset animal models. We studied the effect of treatment with D-pantethine and exposure to ultraviolet-B (UVB) radiation on the development of lenticular opacity in the Emory mouse. METHODS: A total of 164 Emory mice were randomized by litter at weaning to exposure to UVB light at 12 mJ/cm(2) for 6 hr/day (UV) or usual room light (A), and within litter, were further randomized to bi-weekly intra-peritoneal injections of 0.8 g/kg pantethine (T) or no treatment (C). Retro illumination lens photos were taken at 2, 4, 6, 8, and 10 months after weaning, and graded in masked fashion. The animals were sacrificed at 10 months and the lenses analyzed for total pantethine and total cysteamine. RESULTS: Lens pantethine and cysteamine levels were significantly (P < 0.001) higher for the T as compared to C litters. Mean cataract grade increased monotonically over time for all four groups. Unadjusted mean grade for the AT group at 8 (1.32) and 10 (1.86) months appeared lower than for the other groups (AC: 2.17, 2.39; UVC: 1.77, 2.40; UVT: 1.88, 2.37). However, the mean grade for the pantethine-treated litters did not differ significantly from the untreated litters except at 2 months (when untreated litters had significantly lower grades), when adjusting for UV treatment, gender and litter effect. No significant difference in cataract score existed between UV-exposed and ambient litters. Mortality was higher among pantethine-treated (hazard ratio = 1.8, p = 0.05) and UV-exposed animals (hazard ratio = 1.8, p = 0. 03) than among the untreated and unexposed litters. CONCLUSION: Significantly increased lens levels of pantethine are achieved with long-term intra-peritoneal dosing. The impact of pantethine on the progression of lenticular opacity in the Emory mouse is less than has been reported in other models. This level of chronic UVB exposure appeared to have no effect on the development of cataract in this model.