Prediction of temperature profiles in the human skin and subcutaneous tissues

Exact mathematical solutions in terms of confluent hypergeometric and Airy's functions are obtained to study the steady state temperature distributions in human skin and subcutaneous tissues (SST). It is assumed that the skin is exposed to an air environment and heat transfer from the skin occurs by convection, radiation and evaporation. A mathematical model of the SST, accounting for heat conduction, perfusion of the capillary beds and metabolic heat productions of the dermis and subcutaneous tissues, has been solved to obtain interface temperatures for a wide range of environmental temperatures, rates of evaporation of sweat, wind speeds and relative humidities. The solutions provide inter-relationships between interface temperatures, thermal conductivities, metabolic heat production, blood perfusion, thicknesses of various layers of SST and ambient temperature.     

Oligonucleotides, part 5+: synthesis and fluorescence studies of DNA oligomers d(AT)5 containing adenines covalently linked at C-8 with dansyl fluorophore.

The synthesis of oligodeoxynucleotides d(AT)5 in which specific adenines are linked at C-8 position with dansyl fluorophores via a variable polymethylene spacer chain are reported. This was achieved by a strategy involving prelabelling at the monomeric stage followed by solid phase assembly of oligonucleotides to obtain regiospecifically labeled oligonucleotides. Several mono and polydansyl d(AT)5 derivatives in which the fluorophore is linked via ethylene, tetramethylene and hexamethylene spacer arms were synthesised for a systematic study of their fluorescence characteristics. It was observed that (i) enhancements in fluorescence intensity and emission quantum yields are seen due to multiple labelling, (ii) the magnitude of enhancements are related to labelling configuration and (iii) quenching efficiency is minimal with shorter and rigid spacer arms. The results may aid rational design of multiple fluorescent DNA probes for nonradioactive detection of nucleic acids.     

Induction of freezing tolerance in microspore-derived embryos of winter Brassica napus

Freezing tolerance was induced in microspore derived embryos of winter Brassica napus cv. Jet neuf by the addition of ABA or mefluidide to the culture media during embryogenesis. Survival after freezing was estimated by culture of frozen-thawed embryos to plantlets. A higher freezing tolerance (50% survival at –15°C) was induced when 50 M ABA or 3.2 M mefluidide was incorporated initially into the medium during embryogenesis at 25°C followed by culture at 2°C for 3 weeks. When embryos were induced in the absence of ABA or mefluidide and maintained at 2°C for even as long as 12 weeks a lower degree of freezing tolerance (10% survival at –15°C) was obtained. Plants regenerated from embryos hardened maximally by a combination of either ABA or MFD with low temperature did not require further vernalization for flowering.Abbreviations ABA abscisic acid - MFD mefluidide - 2,4-D 2,4-dichlorophenoxyacetic acid - LT₅₀ killing temperature for 50% of the embryos     

Facilitating care of patients with HIV infection by hospital and primary care teams.

To complement the role of primary care teams working with patients with HIV disease and AIDS within greater London and to ease the load on the special hospital units a home support team was developed. It comprises six specialist nurses, a general practitioner trained medical officer, and a receptionist and is funded from regional and district sources and charities. A nurse is available for out of hours and emergency weekend calls, with support from the patient''s general practitioner or the attached medical officer. During the first 18 months 249 patients were seen; the mean duration of care was five months. Nearly a third (18/50, 30%) of patients who were terminally ill died at home. The team''s activities included practical nursing care, emotional support for carers and patients, and advice and guidance to primary care teams. Problems in providing care in patients'' homes included issues relating to confidentiality and 24 hour cover. With the increasing incidence of HIV infection the home support team may be a useful model for care of large numbers of patients with symptomatic HIV disease, especially in large urban areas.     

Catabolic instability,plasmid gene deletion and recombination in Alcaligenes sp. BR60

An Alcaligenes sp. BR60, isolated from surface runoff waters of the Hyde Park industrial landfill, contained a novel 85 kb catabolic plasmid (pBR60) functional in 3-chlorobenzoate (3Cba) degradation. The plasmid exhibited a spontaneous 3.2% frequency of deletion of a 14 kb fragment specifying 3Cba degradation. The deletion mutant BR40 and mitomycin C cured strains were not able to grow on 3Cba and had reversion frequencies of less than 10^-10 cell^-1 generation^-1. Transformation or conjugation of pBR60 into cured strains restored catabolic activity. An EcoRI, BgIII, HindIII and SaII restriction map of the deletion region was constructed, and EcoRI and HindIII fragments spanning the deletion region of the plasmid were cloned in pUC18. Conjugation of resistance plasmid R 68.45 into Alcaligenes sp. BR60, with selection on antibiotics, resulted in the elimination of pBR60 and maintenance of unaltered R68.45. In 30% of the exconjugants, 3Cba degradative capacity was retained, although variation in the regulation of 3Cba degradation was observed in these strains. Hybridization of deletion region fragments to BgIII digested total DNA of BR60 and the R68.45 cured exconjugants revealed the presence of pBR60 deletion region sequences in the chromosome of exconjugants. Hybridization also revealed a repeated sequence flanking the deletion region of pBR60. Selection on 4-chlorobenzoate as a sole source of carbon and energy resulted in the isolation of 4Cba⁺ mutants of Alcaligenes sp. BR60.Abbreviations 3 and 4 Cba chlorobenzoic acid isomers and growth phenotypes - HPLC high pressure liquid chromatography - ATCC American Type Culture Collection     

Antibody directed targeting of methotrexate-containing small unilamellar vesicles

Summary The potential of antibody-linked SUVs containing MTX in anticancer therapy was investigated. The SUVs, mean diameter 50±20 nm, were prepared by probe sonication of MTX-containing MLVs and were covalently linked either to a RAMG or NRG. After incubation with M21 melanoma cells for 2 h, RAMG-linked SUVs showed 2 and 4 times more binding than NRG-linked MTX-containing SUVs or MTX-containing SUVs unlinked to any Ig. Furthermore, on incubating M21 melanoma cells with RAMG-linked ³H MTX-containing SUVs for 2, 4, and 8 h at 4° C or 37° C, a higher radioactivity was associated with cells at 37° C than at 4° C. Membrane immunofluorescence revealed aggregation of and cap formation by RAMG-linked SUVs after 2 h (37° C) and endocytosis at 4 and 8 h at 37° C. Electron microscopic and autoradiographic studies confirmed aggregation of ³H MTX-containing SUVs around and on the surface of M21 cells. Electron microscopy also revealed these SUVs inside invaginations of and under the plasma membrane of melanoma cells. A colony inhibition assay showed that RAMG-linked, MTX-containing SUVs were 60 times, 8 times, and 4.5 times more growth inhibitory than free MTX, NRG-linked MTX-containing SUV, and MTX-containing SUVs unlinked to any Ig, but not toxic to a human kidney cancer line (that did not react with RAMG). Abbreviations used: DPPC, DL- -dipalmitoyl phosphatidylcholine; DTT, dithiothreitol; MTX, methotrexate; (MTX)SUV or MLV, MTX-containing SUV or MLV; MLV, multilamellar vesicle; NRG, normal rabbit immunoglobulin G; RAMG, rabbit antimelanoma IgG; SA, stearylamine; SPDP, N-succinimidy1-3-(2-pyridyldithio)propionate; SUV, small unilamellar vesicle; CHOL, cholesterol; LUV, large unilamellar vesicle; Ig, immunoglobulin; PDP-SA, N-[3-(2-pyridyldithio)-propinyl]stearylamine     

Effect of methionine-sulfoximine on nitrate uptake and photosynthesis in the cyanobacteriumAnabaena doliolum Bharadwaja

l-Methionine-dl-sulfoximine (MSX) stimulated nitrate uptake but inhibited¹⁴CO₂ fixation and O₂ evolution inAnabaena doliolum. Nitrate uptake was inhibited by ammonium (NH ₄ ⁺ ) in the absence of MSX, but not in the presence of MSX. Glutamine or a derivative of it appears to be the actual negative effector of nitrate utilization. In presence of nitrate, MSX-treated cells ofA. doliolum evolve more O₂ than do untreated cells. Our results suggest a close relation between photoassimilation of carbon and utilization of nitrogen.     

Effects of selection criteria on yield stability in chickpea (Cicer arietinum L.)

Summary Selection in the F₃ generation for seed yield, fruiting branches/plant, effective pods/plant, and seed index (100-seed weight) was carried out in two chickpea crosses. Sixty F₅ lines (15 lines/selection criterion) along with check variety were evaluated for seed yield in three distinct environments. The effects of selection criteria on yield stability was examined using linear regression approach and genotype-grouping technique. There were no differences between selection criteria for linear yield responses of F₅ lines to different environments. Within all four selection criteria the lines showed similar linear responses. The non-linear component was relatively higher for lines selected for effective pods and seed index than lines selected for yield and fruiting branches. On the basis of mean yield and coefficient of variation across environments, the seed index was the least effective selection criterion for developing high yielding and stable lines. When the results of stability parameters and genotype-grouping technique were considered together, selection for yield and fruiting branches was highly effective for isolating stable and high yielding lines.