Pollen-based biome reconstruction for southern Europe and Africa 18,000 yr bp

Pollen data from 18,000 ¹⁴C yr bp were compiled in order to reconstruct biome distributions at the last glacial maximum in southern Europe and Africa. Biome reconstructions were made using the objective biomization method applied to pollen counts using a complete list of dryland taxa wherever possible. Consistent and major differences from present‐day biomes are shown. Forest and xerophytic woods/scrub were replaced by steppe, both in the Mediterranean region and in southern Africa, except in south‐western Cape Province where fynbos (xerophytic scrub) persisted. Sites in the tropical highlands, characterized today by evergreen forest, were dominated by steppe and/or xerophytic vegetation (cf. today’s Ericaceous belt and Afroalpine grassland) at the last glacial maximum. Available data from the tropical lowlands are sparse but suggest that the modern tropical rain forest was largely replaced by tropical seasonal forest while the modern seasonal or dry forests were encroached on by savanna or steppe. Montane forest elements descended to lower elevations than today.     

Pulmonary clearance of inhaled 99mTc-DTPA: effects of surfactant depletion by lung lavage

The influence of surfactant depletion on clearance from the lungs of inhaled technetium-99m-labeled diethylenetriamine pentaacetate (99mTc-DTPA) was studied in rabbits. Surfactant was removed by repeated lung lavage with isotone saline. To minimize structural damage to the lungs, pressure generated insufflation with short expiration was utilized. Aerosolized 99mTc-DTPA was administered via a bag-in-bottle system. Radioactivity was measured with a gamma camera and time-activity curves were obtained over the base of the right lung. Six nonlavaged rabbits served as controls. In six lavaged rabbits clearance of 99mTc-DTPA was significantly faster than in controls. In three rabbits given natural surfactant into the trachea after lung lavage, 99mTc-DTPA was eliminated faster than in controls but slower than in surfactant-depleted animals. The results indicate a role of surfactant on clearance rate of 99mTc-DTPA from rabbit lungs. Measurements of 99mTc-DTPA clearance may be useful in studying the function of the surfactant system in different lung disorders.     

A method for studies of an El Tor-associated antigen of Vibrio cholerae O1

A method for studying the biotype El Tor associated mannose-sensitive haemagglutinin (MSHA) of V. cholerae O1 has been developed. By using crude MSHA adsorbed to chicken erythrocytes as solid phase antigen in an enzyme-linked immunosorbent assay (ELISA), antisera against V. cholerae of the El Tor biotype reacted in high titre with the MSHA-coated cells, whereas antisera against vibrios of the classical biotype did not bind significantly, i.e. in higher titre than pre-immune sera. The binding of anti-MSHA serum, or a monoclonal antibody against MSHA, to the MSHA-coated erythrocytes could be efficiently inhibited by crude MSHA as well as by El Tor vibrios whereas neither V. cholerae lipopolysaccharide nor different strains of classical vibrios had any inhibitory effect. These results support the existence of an El Tor-associated immunogen. They also suggest a possibility of determining antibodies against different haemagglutinins in ELISA without having access to purified antigens.     

Effects of energy deprivation on the fly pupil mechanism: evidence for a rigor state

The energy dependence of the pupil pigment-migrations in the fly Musca domestica was studied in live animals, using optical techniques and nitrogen-gas induced anoxia. The results obtained can be summarized in 3 points:

1. Energy deficiency can make the pupil mechanism stop in any state, extreme or intermediate.
2. Anoxia induced during intermittent stimulation makes the pupil stop in the closed state (aggregated pigment granules).
3. During long-term anoxia the pupil very slowly opens (dispersal of pigment granules), irrespective of ambient intensity.

The slow anoxic opening (point 3) is more than 1000 times slower than that predicted for free diffusion of pigment granules in water. Assuming realistic values of cytoplasm viscosity, this implies that anoxia causes the pigment granules to attach to rigid structures in the cells, in analogy with the rigor state in anoxic muscles. The rigor phenomenon in the pupil mechanism prevents experimental discrimination between active and passive processes of pigment migration. Normal pupil opening has a time course which agrees reasonably with a passive diffusion process, but it is argued that an active transportation of granules away from the rhabdom is more likely in the dark adapted eye.     

A critical view on conservative mutations

By analysing the surface composition of a set of protein 3D structures, complemented with predicted surface compositional information for homologous proteins, we have found significant evidence for a layer composition of protein structures. In the innermost and outermost parts of proteins there is a net negative charge, while the middle has a net positive charge. In addition, our findings indicate that the concept of conservative mutation needs substantial revision, e.g. very different spatial preferences were found for glutamic acid and aspartic acid. The alanine screening often used in protein engineering projects involves the substitution of residues to alanine, based on the assumption that alanine is a "neutral" residue. However, alanine has a high negative correlation with all but the non-polar residues. We therefore propose the use of, for example, serine as a substitute for the residues that are negatively correlated with alanine.     

A phase II study of allogeneic natural killer cell therapy to treat patients with recurrent ovarian and breast cancer

BackgroundNatural killer (NK) cells derived from patients with cancer exhibit diminished cytotoxicity compared with NK cells from healthy individuals. We evaluated the tumor response and in vivo expansion of allogeneic NK cells in recurrent ovarian and breast cancerMethodsPatients underwent a lymphodepleting preparative regimen: fludarabine 25 mg/m² × 5 doses, cyclophosphamide 60 mg/kg × 2 doses, and, in seven patients, 200 cGy total body irradiation (TBI) to increase host immune suppression. An NK cell product, from a haplo-identical related donor, was incubated overnight in 1000 U/mL interleukin (IL)-2 prior to infusion. Subcutaneous IL-2 (10 MU) was given three times/week × 6 doses after NK cell infusion to promote expansion, defined as detection of ≥100 donor-derived NK cells/μL blood 14 days after infusion, based on molecular chimerism and flow cytometryResultsTwenty (14 ovarian, 6 breast) patients were enrolled. The median age was 52 (range 30–65) years. Mean NK cell dose was 2.16 × 10⁷cells/kg. Donor DNA was detected 7 days after NK cell infusion in 9/13 (69%) patients without TBI and 6/7 (85%) with TBI. T-regulatory cells (Treg) were elevated at day +14 compared with pre-chemotherapy (P = 0.03). Serum IL-15 levels increased after the preparative regimen (P = < 0.001). Patients receiving TBI had delayed hematologic recovery (P = 0.014). One patient who was not evaluable had successful in vivo NK cell expansionConclusionsAdoptive transfer of haplo-identical NK cells after lymphodepleting chemotherapy is associated with transient donor chimerism and may be limited by reconstituting recipient Treg cells. Strategies to augment in vivo NK cell persistence and expansion are needed.     

Identification of flotillin-1 as an interacting protein for antisecretory factor

Antisecretory factor (AF) also named S5a/Rpn10 was originally identified through its capacity to inhibit intestinal hypersecretion and was later shown to be a component in the proteasome complex. AF is also a potent anti-inflammatory agent and can act as a neuromodulator. In this study we used yeast two-hybrid screens, with yeast strain PJ692A transformed with the bait vector pGBKT7 (AF aa 1-105) against yeast strain Y187 pretransformed with human brain or placenta cDNA libraries, to identify AF-binding proteins. Flotillin-1 was identified as a specific interacting factor with AF. Immunohistochemistry showed co-localization of AF and flotillin-1 in nervous tissue. Flotillin-1 is an integral membrane protein and a component of lipid rafts, a membrane specialization involved in transport processes. Intracellular AF may affect secretory processes by regulating the localization of signal proteins to lipid rafts.     

Relationships between pupil working range and habitat luminance in flies and butterflies

The luminance range over which the pupil mechanism operates was measured with pupil reflectometry in 11 species of butterflies and 13 species of dipteran flies. The different species were selected to be as different as possible regarding the range of ambient luminances in which they are active. Habitat luminance ranges were also measured and correlated to luminances in the experimental situation. The pupil mechanism in butterflies operates in the centre of the luminance range in which the different species are active. Three distinct groups of butterflies with pupil sensitivities matched to their specific types of activity pattern were identified: species active only in direct sunlight, species active also in shaded places and species extending their activity into dawn and dusk. Quite differently, the pupil mechanisms of dipteran flies operate in the upper end of the ambient luminances, and in some species well above the luminances normally encountered by the animal. All fly pupils start to close roughly at the same luminance, irrespective of the luminances in which the species are active. The results suggest that the most important role for the pupil mechanism in many of the butterfly species is to maximize acuity over a wide range of luminances, whereas in flies it is to avoid saturation of transduction units and thereby maximize the photoreceptor's signal-to-noise ratio at high light intensities. Accepted: 1 July 1997     

A Method for Recording the Motor Activity of the Reticulum in Cattle

A method for recording the motility of the reticulum in normal cattle has been devised. The method is based on measurement of the pressure variations occurring in connection with the reticular contractions. The pressure is transferred through open, water-filled catheters via a pressure transducer to an electromanometer, from which it is recorded with the aid of a mingograf. Mean values for the interval, duration and amplitude of the reticular contractions in 10 normal cows are given. The method permits recording in intact animals without any preliminary measures, and can therefore be used in clinical cases.     

Expression and detection of different biotype-associated cell-bound haemagglutinins of Vibrio cholerae O1

The expression of two cell-bound haemagglutinins, one sensitive to L-fucose (FSHA) and the other to D-mannose (MSHA), on Vibrio cholerae O1 strains of both the classical and the El Tor biotypes was studied by (i) agglutination of chicken and human group O erythrocytes in the presence of L-fucose or D-mannose, (ii) binding of the bacteria to L-fucose- and D-mannose-coated agarose beads, and (iii) agglutination of the bacteria by 'biotype-specific' antisera. All of the 12 classical strains studied that were isolated before 1979 gave FSHA of human O erythrocytes whereas only 6 of 17 classical strains isolated during recent epidemics expressed FSHA; a few of the classical strains expressed MSHA in addition to FSHA. All the El Tor strains gave MSHA of chicken erythrocytes and one strain also expressed FSHA. Both the cell-bound HAs were optimally expressed during the exponential phase of growth; FSHA markedly decreased during the late exponential phase while the MSHA usually persisted into the stationary phase. The expression of FSHA and MSHA correlated very well with the direct binding of vibrios to fucose- and mannose-coated agarose beads, respectively. Antiserum 'specific' for classical vibrios agglutinated classical strains expressing FSHA and also the El Tor strain exhibiting FSHA. Similarly, the anti-El Tor serum agglutinated all El Tor strains and also classical strains expressing MSHA, suggesting that the 'biotype-specific' sera were specific for the biotype-associated cell-bound HAs.