Effects of permethrin on aquatic organisms in a freshwater stream in south-central Alaska.

Permethrin (0.5%) was applied to individual Lutz spruce, Picea x lutzii Little, to protect them from attack by spruce beetles, Dendroctonus rufipennis (Kirby). Residue levels were monitored in a freshwater stream above, adjacent to, and below the treatment site at intervals before, during, and after treatment. Maximum residue levels in the stream within the treatment site ranged from 0.05 +/- 0.01 ppb 5 h after treatment to 0.14 +/- 0.03 ppb 8-11 h after treatment, with a decrease to 0.02 +/- 0.01 ppb 14 h after treatment. Levels of permethrin in standing pools near the stream within the treatment site were 0.01 +/- 0.01 ppb. Numbers of drifting aquatic invertebrates increased 2-fold during treatment and 4-fold 3 h after treatment and declined to before spray numbers within 9 h. Terrestrial insects did not appear to respond to treatments because none was found in stream drift samples. Trout fry (Dolly Varden), aquatic insect larvae, and periphyton (attached algae) within and below the treatment site during and after treatment did not show signs of mortality compared with an upstream untreated control site.     

A topological model for the haemolysin translocator protein HlyD

Summary A topological model for HlyD is proposed that is based on results obtained with gene fusions of lacZ and phoA to hlyD. Active H1yD-LacZ fusion proteins were only generated when lacZ was fused to hlyD. within the first 180 by (60 amino acids). H1yD-PhoA proteins exhibiting alkaline phosphatase (AP) activity were obtained when phoA was inserted into hlyD. between nucleotides 262 (behind amino acid position 87) and 1405 (behind amino acid position 468, only 10 amino acids away from the C-terminus of HlyD Active insertions of phoA into the middle region of hlyD. were not observed on in vivo transposition but such fusions exhibiting AP activity could be constructed by in vitro techniques. A fusion protein that carried the PhoA part close to the C-terminal end of HlyD proved to be the most stable HlyD-PhoA fusion protein. In contrast to the other, rather unstable, HlyD-PhoA⁺ fusions, no proteolytic degradation product of this HlyD-PhoA protein was observed and nearly all the alkaline phosphatase activity was membrane bound. Protease accessibility and cell fractionation experiments indicated that the alkaline phosphatase moiety of this fusion protein was located in the periplasm as for all other HlyD-PhoA⁺ proteins. These data and computer-assisted predictions suggest a topological model for HlyD with the N-terminal 60 amino acids located in the cytoplasm, a single transmembrane segment from amino acids 60 to 80 and a large periplasmic region extending from amino acid 80 to the C-terminus. Neither the HlyD fusion proteins obtained nor a mutant HlyD protein that had lost the last 10 amino acids from the C-terminus of HlyD exhibited translocator activity for HlyA or other reporter proteins carrying the HlyA signal sequence. The C-terminal 10 amino acids of HlyD showed significant similarity with the corresponding sequences of other HlyD-related proteins involved in protein secretion.     

Zur Funktion von Warnfarben: Die Reaktion junger Stare auf wespenähnlich schwarz-gelbe Attrappen

Social regulation of developmental rate of the African cichlid fish, Haplochromis bur-toni, was studied experimentally. Broods were raised under three different social conditions: total isolation, with no visual, physical or chemical contact with siblings; physical isolation, with no physical or chemical contact with siblings; and in social groups. Development of behavior and color patterns were observed in fish from 2 to 14 weeks of age. Males were sacrificed at 4-week intervals to measure growth and maturation state. Results showed that developmental rate is influenced by the social environment. Males with no territories (raised in groups) grew and matured more slowly than those in all other conditions. These males were not prevented from maturing but both the rate and phenotypic expression of maturation were inhibited.     

A rapid fluorometric method for the estimation of DNA in cultured cells

We present here a procedure for the rapid measurement of both DNA and protein from the same aliquot of cell lysate. DNA estimates obtained by this method were compared to replicate determinations using the method of Kissane and Robins (1). The optimal range for the estimation of DNA (1 to 20 μg) is well suited for use with portions of extracts from individual cell cultures; the remainder of the extract remains available for enzyme assays or other parallel determinations.     

Isolation and identification of spirorenone metabolites from the monkey (Macaca fascicularis)

The plasma level of spirorenone was determined 3 h after 1, 8, 22 and 46 daily oral administrations of 20 mg/kg to two female and two male monkeys ($\text{Macaca fascicularis}$). A fifth animal, female, was treated with eight daily doses of tritium-labelled drug and was completely bled from the carotid vein 4 h after the last administration in order to isolate and identify plasma metabolites.After repeated daily doses of spirorenone the mean plasma level of unchanged drug was 711 ± 213 ng/ml. In the plasma of the fifth animal four radioactively labelled compounds could be detected after extraction and subsequent HPLC separation. Mass spectrometric identification of three of the substances indicated 1,2-dihydrospirorenone, hydroxy-1,2-dihydrospirorenone and the unchanged drug itself.     

Electrophoretic and biochemical studies of human aldehyde dehydrogenase isozymes in various tissues

Four major ALDH isozymes have been identified in human tissues using starch gel electrophoresis and isoelectric focusing. The isozyme bands have been termed as ALDH I, II, III and IV according to their decreasing electrophoretic migration and increasing isoelectric point. The isozymes have been partially purified via preparative isoelectric focusing. Kinetic characteristics of ALDH I and II were found to be quite similar to ALDH enzyme 2 and enzyme 1 described earlier by Greenfield and Pietruszko (Biochem Biophys Acta, $\text{483}$ 35–45 1977). ALDH III and IV showed a very high Km for propionaldehyde (1.0–1.5 mM at pH 9.5) and were not inhibited by disulfiram at pH 9.5. A variant phenotype of ALDH which lacked in isozyme I was detected in various tissues from Japanese individuals. Comparative kinetic properties of normal and variant enzyme are given.     

Neue diterpene und neue dihydrochalkon-derivate sowie weitere inhaltsstoffe aus Helichrysum-arten

The investigation of 25 further Helichrysum species afforded in addition to known compounds a new diterpene, an oxo-geranyllinalol, a second one, most probably a cembrene derivative, and three dihydrochalkone derivatives. The distribution of the constituents in South African Helichrysum species is discussed briefly.