Purification and characterization of a lysophospholipase from human amnionic membranes

We have identified the presence of a lysophospholipase in human placental tissues and have purified this enzyme from the amnion. The specific activity was highest in the amnion and decreased across adjacent tissues. The purification involved the use of DEAE-Sephadex, phenyl-Sepharose, hydroxylapatite, and sulfylpropyl Sephadex chromatography. The activity of the purified enzyme toward palmitoyl lysophosphatidylcholine is 2.5 mumol min-1 mg-1 and the pH optimum is 7.0. The enzyme is not inhibited by EDTA and does not appear to have a metal ion requirement. The enzyme may be of membrane origin; the purified enzyme requires the presence of detergent during storage. The effects of substrate composition and physical state on enzymatic activity were explored. The enzyme was not active toward mono-, di-, or triglycerides, nor toward diacyl phospholipid. The enzyme was active toward myristoyl and palmitoyl lysophosphatidylcholine at concentrations where these substrates spontaneously form micelles or where Triton X-100 was used to induce co-micellization of the substrate at low concentrations with detergent. A role for this enzyme in processing the lysophospholipid product of phospholipase A action must be considered in evaluating arachidonic acid production in human fetal membranes and placental tissue, particularly during the initiation of labor.     

Hemophilus vaginalis bacteremia.

During 1975--77 Hemophilus vaginalis bacteremia occurred post partum in eight previously healthy women. Seven had been admitted for delivery at term and one because of threatened abortion. Six underwent cesarean section. Post-partum pyrexia and neutrophilia were the main features. All the patients recovered uneventfully while receiving antibiotics. H. vaginalis is an infrequent agent of bacteremia; it affects predominantly women after obstetric trauma.     

Energy from vascular plant wastewater treatment systems

Water hyacinth (Eichhornia crassipes), duckweed (Spirodela sp. andLemna sp.), water pennywort (Hydrocotyle ranunculoides), and kudzu (Pueraria lobata) were anaerobically fermented using an anaerobic filter technique that reduced the total digestion time from 90 d to an average of 23 d and produced 0.14-0.22 m³ CH₄/kg (dry weight) (2.3-3.6 ft³/lb) from mature filters for the 3 aquatic species. Kudzu required an average digestion time of 33 d and produced an average of 0.21 m³ CH₄/kg (dry weight) (3.4 ft³/lb). The anaerobic filter provided a large surface area for the anaerobic bacteria to establish and maintain an optimal balance of facultative, acid-forming, and methane-producing bacteria. Consequently the efficiency of the process was greatly improved over prior batch fermentations.     

Novel surface lipids of diapausing Manduca sexta pupae. Long chain oxoalcohol esters of acetoacetic, hydroxybutyric, and acetic acids

Ester components in the surface wax from diapausing tobacco hornworm pupae, Manduca sexta L., were separated by thin layer chromatography and gas-liquid chromatography, and characterized by infrared spectroscopy and gas-liquid chromatography-mass spectrometry. Three groups of esters were identified as natural derivatives of acetic acid, acetoacetic acid, and 3-hydroxybutyric acid. The major ester fraction was identified as a mixture of C26 (10%), C27 (5%), and C28 (85%) oxoalcohol esters of acetoacetic acid. The major homolog consisted of equal amounts of 11-oxooctacosanyl 3-oxobutanoate and 12-oxooctacosanyl 3-oxobutanoate. Lesser amounts of 11- and 12-oxooctacosanyl and n-octacosanyl esters of acetic and 3-hydroxybutyric acids were also identified. The chain length distributions of these C26, C27, and C28 oxoalcohol and n-primary alcohol ester moieties, as well as the isomeric ratios for the 11- and 12-oxoalcohol isomers, were similar to the oxoaldehydes and unesterified oxoalcohols previously identified by Buckner et al (Buckner, J. S., Nelson, D. R., Haak, H., and Pomonis, J. G. (1984) J. Biol. Chem. 259, 8452-8470) as lipid components of the surface wax of M. sexta pupae.     

Studies on human uterine cervix and rat uterus using S-, X- and Q-band electron-spin-resonance spectroscopy.

In previous studies we have reported on the detection of a strong e.s.r. signal in samples of normal human cervix; the signal is much reduced or absent in samples of invasive cancer of the cervix. In order to identify the species responsible for the strong signal, we have used X-, S- and Q-band e.s.r. spectroscopy. The major signal that is detectable in ground-up samples of cervix preserved at -196 degrees C has features consistent with the presence of a peroxy free radical. Good agreement with the experimental findings was obtained by computer simulation, using values for the g-tensor of gx = 2.002, gy = 2.005 and gz = 2.036. The peroxy radical is produced on grinding the normal cervix samples to a powder under liquid N2, and appears to be formed by modification of a pre-existing oxygen-containing complex. Control experiments eliminated the possibility that the strong signals seen in frozen powders prepared from normal cervix were artefacts only of the grinding procedure. Experiments with rats in vivo and with cervix samples in vitro are consistent with the conclusion that the peroxy radical is formed by disturbing the cyclo-oxygenase system that is involved in prostaglandin synthesis.     

Formation of lethal blood clots in fishes

Evidence is presented of lethal blood clot formation in fishes. A variety of factors commonly encountered under aquacultural conditions may generate such clots.     

Temporal and spatial differences in the emission of calls by pipistrelle bats<Emphasis Type="Italic">Pipistrellus pipistrellus</Emphasis> and<Emphasis Type="Italic">P. pygmaeus</Emphasis>

The number of orientation, feeding and social calls emitted by pipistrelle batsPipistrellus pipistrellus Schreber, 1774 andP. pygmaeus Leach, 1825 was recorded throughout the night at eight different sites. Social calls were unaffected by weather variables, whereas orientation calls and feeding buzzes were both significantly affected by cloud and temperature conditions. The number of emissions of each call type was significantly different between sites, indicating that the bats used different sites for different activities. Significant positive correlations between all three combinations of call types occurred only during the middle of the night, corresponding with the nadir of flying insects. This suggests that bats were engaged in activities other than feeding at this time, such as territory protection or mate attraction.