Stereospecific formation of 1,2-epoxypropane, 1,2-epoxybutane and 1-chloro-2,3-epoxypropane by alkene-utilizing bacteria

Resting cells of ethene grown Mycobacterium 2W produced 1,2-epoxypropane stereospecifically from propene as revealed by optical rotation, ¹H n.m.r. using a chiral shift reagent, and also by complexation gas chromatography involving a glass capillary column coated with an optically active metal chelate. The gas-liquid chromatography method allowed the rapid screening of 11 strains with regard to stereospecific formation of 1,2-epoxypropane, 1,2-epoxybutane and 1-chloro-2,3-epoxypropane. Bacteria grown on either ethene, propene or butadiene all predominantly produced the R form of 1,2-epoxypropane from propene and 1,2-epoxybutane from 1-butene while the strains tested for 1-chloro-2,3-epoxypropane production from 3-chloro-1-propene predominantly accumulated the S enantiomer.     

Bronchodilatory properties of 2-decarboxy-2-hydroxymethyl prostaglandin E1

We evaluated in a double-blind study the bronchodilatory properties of 2-decarboxy-2-hydroxymethyl prostaglandin E₁ (PGE₁-carbinol), described recently as a nonirritant bronchodilator in animals. Fifteen asthmatic patients received by inhalation single doses of 1, 10, and 30 μg PGE₁-carbinol, 55 μg PGE₂, and placebo (10% ethanol in normal saline, which was also used as diluent for the PGs). Such pulmonary function tests as forced expiratory volume in 1 second, forced vital capacity, and maximal expiratory flow were monitored during 2 hours following inhalation of each compound. 10 and 30 μg PGE₁-carbinol produced significant but short-acting bronchodilation, similar to that caused by 55 μg PGE₂. One-third of the patients reported mild cough and throat irritation during and shortly after inhalation of 30 μg PGE₁-carbinol or 55 μg PGE₂. Placebo and 1 μg PGE₁-carbinol produced minimal side effects, but neither agent caused bronchodilation. In an adjunctive, unblinded trial, the same patients received 400 μg fenoterol. Fenoterol caused greater bronchodilation 15 and 30 minutes after inhalation than did the PGs in the double-blind study.     

Biofeedback control of migraine headaches: A comparison of two approaches

In order to assess the relative effectiveness of finger warming and temporal blood volume pulse reduction biofeedback in the treatment of migraine, 22 female migraine patients were assigned to one of three experimental conditions: temporal artery constriction feedback, finger temperature feedback, or waiting list. Biofeedback training consisted of 12 sessions over a 6-week period. All patients completed 5 weeks of daily self-monitoring of headache activity (frequency, duration, and intensity) and medication before and after treatment. Treatment credibility was assessed at the end of Sessions 1, 6, and 12. Results showed that temporal constriction and finger temperature biofeedback were equally effective in controlling migraine headaches and produced greater benefits than the waiting list condition. Power analyses indicated that very large sample sizes would have been required to detect any significant differences between the two treatment groups. No significant relationships were found between levels of therapeutic gains and levels of thermal or blood volume pulse self-regulation skills. Likewise, treatment outcome was not found to be related to treatment credibility. Further analyses revealed that changes in headache activity and medication were associated with changes in vasomotor variability. Because blood volume pulse variability was not significantly affected by biofeedback training, questions about its role in the therapeutic mechanism are raised.This research was supported in part by grants from the Quebec Ministry of Education and the Quebec Ministery of Social Affairs to the first author, and an award from the Medical Research Council of Canada to the second author. The authors are indebted to Drs. Frank Andrasik, Howard Barbaree, Edward Blanchard, Martin Ford, and Patrick McGrath, as well as to two anonymous reviewers, for their helpful comments on an earlier draft of this paper.     

Vegetation succession on the dunes near Oostvoorne,The Netherlands,since 1934, interpreted from air photographs and vegetation maps

The vegetation succession on the dunes near Oostvoorne, The Netherlands has been followed by means of a novel combination of repeated large-scale vegetation mapping and air photograph interpretation. Vegetation units have been discerned on the formation level because these could be distinguished fairly easily on the photographs and because the rates of change are appropriate to the time interval chosen. Nineteen formations were distinguished. Five 1:6250 maps were constructed, reflecting the formation pattern in 1934, 1943, 1959, 1972 and 1980. An overlay with 2736 grid points at 25 m field distance was used to quantify changes in the formation pattern.The results suggest a pronounced multiple pathway succession with nevertheless three principal trajectories of succession from pioneer to woodland vegetation. The outer dunes, which have originated since 1910, are distinct in successional characteristics from the inner dunes, which already existed but were released from heavy grazing pressure in 1910. The rate of change in the outer dunes was high in the beginning and is slowly decreasing eversince. In the inner dunes it went the other way around. Through visual extrapolation the likely formation patterns in 1910 and in 2000 were estimated.Transition frequencies proved highly variable for most formations. Moreover, strong spatial dependence was found. Limitations in the use of Markov models in cases of long-term succession in heterogeneous environments are discussed.Nomenclature follows the same sources as in van der Maarel et al. (1984).Field work carried out 1980–1981 when the authors were at the Division of Geobotany, University of Nijmegen. We thank Jos Rijntjes, Nijmegen, for his cooperation in the field. Vegetation maps were prepared and calculations performed at Uppsala. We thank the Foundation Het Zuid-Hollands Landschap, Rotterdam, for providing facilities and a grant for fieldwork as well as additional means to reproduce the vegetation maps. Two reviewers gave useful comments.     

T-cell-mediated regression of "spontaneous" and of Epstein-Barr virus-induced B-cell transformation in vitro: studies with cyclosporin A

The regression of Epstein-Barr (EB) virus-transformed B-cell outgrowth which is seen in experimentally-infected cultures of blood mononuclear (UM) cells from healthy seropositive donors can be abolished in medium containing the T-cell-suppressive agent cyclosporin A (CSA) at concentrations of 0.05 microgram/ml and above. CSA mediates its effect within the first 4 days post-infection of the UM cells and this prevents subsequent in vitro generation of the EB virus-specific cytotoxic-T-cell response which normally brings about regression. Regression can be fully restored by supplementing the CSA-treated culture with interleukin 2 (IL-2)-containing culture supernatants or indeed with purified IL-2 itself, suggesting that CSA mediates its effect in this system through inhibiting the endogenous production of IL-2 which is required to amplify the virus-specific cytotoxic response. "Spontaneous transformation" to EB virus genome-positive lymphoblastoid cell lines in noninfected cultures of UM cells from healthy seropositive donors, though rare in normal medium, is enhanced to such a degree in the presence of CSA that, for many donors, the phenomenon becomes titratable against input cell dose across the 2.0 X 10(6)-2.5 X 10(5) cells/culture range. Cell mixing experiments suggest that the spontaneously transformed cell lines which arise with such efficiency under these conditions do so not by direct in vitro outgrowth of progenitor cells transformed by the virus in vivo, but by a two-step mechanism involving virus release and secondary infection in vitro.     

Estimation of the mechanical parameters of the human respiratory system

A numerical algorithm has been developed for the estimation of the mechanical parameters of the human respiratory system. In order to estimate the pulmonary resistance and the dynamic pulmonary elastance, the transpulmonary pressure and the airflow at the mouth or nose are expanded in Chebyshev series. The nonlinear mathematical lung model and a set of measurements for airflow and pressure are then handled by the numerical technique. The lung model includes a component to account for turbulent flow in the larynx and trachea. This contribution presents an alternative method for lung parameter estimation and differs from most existing methods in that it does not need measurements for the tidal volume. It therefore eliminates the use of a body plethysmograph. The method may also find potential application to various other parameter identification problems.     

Histidine decarboxylase of Lactobacillus 30a. Sequences of the overlapping peptides, the complete alpha chain, and prohistidine decarboxylase

The complete amino acid sequence of the alpha chain of histidine decarboxylase of Lactobacillus 30a has been established by isolation and analysis of the eight methionine-containing tryptic peptides of this chain. These peptides provide the overlaps required to order all nine peptides derived by complete cyanogen bromide cleavage of the alpha chain (Huynh, Q.K., Vaaler, G.L., Recsei, P.A., and Snell, E.E. (1984) J. Biol. Chem. 259, 2826-2832). Ordering of six of the latter peptides was confirmed by isolation and analysis of four peptides derived by incomplete cyanogen bromide cleavage. The alpha chain is composed of 226 residues and has a molecular weight of 24,892 calculated from the sequence. These results and the previously determined sequence of the beta chain (Vaaler, G.L., Recsei, P.A., Fox, J.L., and Snell, E.E. (1982) J. Biol. Chem. 257, 12770-12774) establish the complete amino acid sequence of the enzyme and of the pi chain of prohistidine decarboxylase. The latter is composed of 307 amino acids and has a calculated molecular weight of 33,731. Four segments of the pi chain sequence are repeated. The bond between Ser-81 and Ser-82 that is cleaved during proenzyme activation is in an uncharged portion of the sequence that is rich in serine and threonine residues and is predicted to be part of a beta sheet structure.     

Characterization of purified cytochrome b-c1 complex from Rhodopseudomonas sphaeroides R-26

A highly purified cytochrome b-c1 complex from Rhodopseudomonas sphaeroides R-26 was isolated by a procedure involving Triton X-100 solubilization, calcium phosphate column chromatography, and ammonium sulfate fractionation. The purified enzyme complex contains, in nanomoles/mg of protein, cytochrome b, 8.3; cytochrome c1, 8.3; iron-sulfur protein, 15; phospholipids, 182; and ubiquinone, 5. Four major polypeptides with apparent molecular weights of 48,000, 30,000, 24,000, and 12,000 were detected in the sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The Mr = 48,000 and 30,000 proteins are cytochromes b and c1, respectively. The enzyme complex catalyzes electron transfer from ubiquinol to cytochrome c with a specific activity of 12.6 mumol of cytochrome c reduced per min/mg of protein at 23 degrees C. This is lower than that of the mitochondrial enzyme, although both systems have similar essential redox components and a similar Km for ubiquinol. The activity is fully sensitive to antimycin A and 5-n-undecyl-6-hydroxy-4, 7-dioxobenzothiazole. The enzyme complex is stable at neutral pH and at lower temperatures, but became less stable when the incubation temperature was raised. At 37 degrees C, the half-life is 15 min. The enzymatic activity was insensitive to treatment with N',N'-dicyclohexylcarbodiimide. No p-chloromercuriphenylsulfonate-alkylable sulfhydryl groups were detected. The major phospholipids associated with the purified enzyme complex are phosphatidylcholine, phosphatidylethanolamine, and phosphatidylglycerol with molar per cent distributions of 25, 21, and 35, respectively. About 60% of the enzymatic activity was abolished upon treatment with phospholipase A2. The phospholipase A2-inactivated activity can be partially restored by the addition of EDTA followed with phospholipids prepared from either the cytochrome b-c1 complex of the same source or a mixture of phosphatidylglycerol and asolectin.(ABSTRACT TRUNCATED AT 250 WORDS)     

A simple purification of calmodulin by reversed phase chromatography with hydrophobic polymer 3520

A new adsorption chromatography procedure for the purification of calmodulin from bovine brain was developed using polymeric adsorbent 3520. Calmodulin was first isolated by DEAE-Cellulose column chromatography and further purified to apparent homogeneity following elution with 50% ethanol from the adsorbent column. Polyacrylamide gel electrophoresis showed one band either in the presence of Ca2+ or EGTA. The polymeric adsorbent 3520 is a non-polar polymer lacking exchangeable groups. The selective adsorption of calmodulin is based on hydrophobic interaction within the matrix, and is Ca2+ independent. Neither high salt (0.5 M NaC1) nor EGTA (5 mM) was able to elute the CaM from the adsorption column whereas ethanol (50%) eluted it completely. This method is simple to use and it provides highly purified calmodulin with high yield.     

Social stimulation and the resumption of copulation in Rhesus (Macaca mulatto) and stumptail (Macaca arctoides) Macaques

Copulatory data derived from observations of social groups of rhesus and stumptail macaques were analyzed to test the hypothesis that pairs of animals would resume copulation significantly sooner if a second male copulated with the female shortly after the first male’s ejaculation. Data from both groups supported the hypothesis. These results, extending previous studies in Macaca nemestrina,suggest that the shortening of copulatory intervals by social stimuli occurs in several species, both in social groups and in experimentally created triads. These findings also are consistent with the hypothesis that socially mediated resumption of mating is related to intrasexual competition among males.