The Opecoelidae (Digenea) of sparid fishes of the western Mediterranean. III. Macvicaria Gibson & Bray, 1982

Macvicaria obovata (Molin) n. comb. is redescribed from Sparus aurata off the Mediterranean coast of France and a neotype is designated. Specimens from Oblada melanura off Israel may belong to the same species. It is mainly characterized by the uterine extension between the ovary and the anterior testis and the lack of a vitelline confluence in the forebody. M. maillardi n. sp. is also described from Sparus aurata off the southern coast of France. Its uterus does not pass between ovary and testes and the vitelline fields are confluent in the forebody. M. crassigula (Linton) n. comb. is redescribed from Diplodus annularis, D. sargus, D. vulgaris, Pagellus erythrinus and Sparus pagrus off Corsica, Calamus bajonado off Bermuda, Spicara smaris, D. annularis off Yugoslavia, D. sargus off Israel, and D. cervinus, Sparodon durbanensis and Cheilodactylus fasciatus in the SW Indian Ocean. It is similar to M. maillardi, but differs in being smaller, having a greater sucker ratio and a larger pharynx. It may well be a species-complex. M. dubia (Stossich) n. comb. is redescribed from Oblada melanura off Corsica and Yugoslavia. It is similar to M. maillardi and M. crassigula, but has a more anteriorly situated genital pore.     

The Lepocreadiidae (Digenea) of fishes from the north-east Atlantic: review of the genus Neolepidapedon Manter, 1954, with a description of N. smithi n. sp.

A new species, Neolepidapedon smithi, is described from the fish Mora moro in the north-eastern Atlantic Ocean and is distinguished from other members of the genus. It differs from its congeners in the extension of the vitellarium into the forebody and/or the body shape. The genus Neolepidapedon is reviewed and a key to species given. The genus has previously contained up to 20 species, but is here restricted to eight species, which possess a very thick male duct wall within the cirrus-sac, a narrow internal seminal vesicle, an excretory vesicle restricted to the hindbody and no eye-spots. The remaining nominal species with a relatively thin-walled internal male duct, a globular internal seminal vesicle, an excretory system which reaches into the forebody and eye-spots are considered to belong to a separate group which is related to Opechona. Some of these species were included by Yamaguti (1971) in his new subgenus Neolepidapedon (Neolepidapedoides), which is raised to full generic status. Eight new combinations are made: Neolepidapedoides belizensis (Fischthal, 1977), N. dollfusi (Durio & Manter, 1968), N. equilatum (Siddiqi & Cable, 1960), N. hypoplectri (Nahhas & Cable, 1964), N. israelense (Fischthal, 1980), N. macrum (Overstreet, 1969), N. medialunae (Montgomery, 1957) and N. mycteropercae (Siddiqi & Cable, 1960).     

Actinomycetes inducing phytotoxic or fungistatic activity in a Douglas-fir Forest and in an adjacent area of repeated regeneration failure in Southwestern Oregon

Actinomycetes were isolated from the upper 1 - 3 cm of the soil layer in a well-developed forest and in an adjacent clearcut area where Douglas-fir [Pseudotsuga menziesii (MIRB.) Franco] regeneration had been impaired for two decades. The population density in the clearcut area was two times as high as that in the forested area. The percentage of actinomycetes that inhibited seed germination of the test plants was significantly higher in isolates obtained from the clearcut area than in those obtained from the forested area, and isolates from the clearcut showed five times the phytotoxic effect of those from the forest. Some actinomycete isolates, 4 % from the clearcut and 2.6 % from the forest, significantly reduced in vitro growth of two common ectomycorrhizal fungi of Douglas-fir,Laccaria laccata andHebeloma ovstuliniforme. Two actinomycete isolates from the clearcut reduced fungal growth by 40 % and 73 %. Reduction of the nutrient in the growth medium did not affect the antifungal activity of the actinomycetes. The data support the idea that, along with other factors, phytotoxic and antifungal actinomycetes may suppress natural regeneration or establishment of planted seedlings - either directly or. indirectly - through inhibition of seed germination or of mycorrhizal fungi.     

A Freeze-Sectioning Method for Preparation of the Detergent-Resistant Cytoskeleton Identifies Stage-Specific Cytoskeleal Proteins and Associated mRNA in Xenopus Oocytes and Embryos

Proteins of the detergent-resistant cytoskeleton fraction and the detergent-soluble fraction from Xenopus oocytes and embryos are examined using a procedure which allows rapid and uniform extraction of tissues and large, single cells. SDS-polyacrylamide gels reveal only a few prominent cytoskeletal proteins in the early embryo, however qualitatively different proteins begin to appear after gastrulation. Incorporation of [³⁵S]-methionine into newly synthesized proteins indicates that there is synthesis and assembly of proteins into the cytoskeleton, but the amount remains low until after gastrulation. The use of nucleic acid probes for alpha-tubulin and actin mRNA indicates that about 80% of these mRNAs in the oocyte and meiotically mature egg are bound to the detergent-resistant cytoskeleton.     

Soluble derivatives of the beta amyloid protein precursor of Alzheimer's disease are labeled by antisera to the beta amyloid protein

The amyloid deposited in Alzheimer's disease (AD) is composed primarily of a 39-42 residue polypeptide (beta AP) that is derived from a larger beta amyloid protein precursor (beta APP). In previous studies, we and others identified full-length, membrane-associated forms of the beta APP and showed that these forms are processed into soluble derivatives that lack the carboxyl-terminus of the full-length forms. In this report, we demonstrate that the soluble approximately 125 and approximately 105 kDa forms of the beta APP found in human cerebrospinal fluid are specifically labeled by several different antisera to the beta AP. This finding indicates that both soluble derivatives contain all or part of the beta AP sequence, and it suggests that one or both of these forms may be the immediate precursor of the amyloid deposited in AD.     

The combined effects of chlorine and ammonia on litter breakdown in outdoor experimental streams

The response of Potamogeton crispus L. breakdown to controlled doses of different levels of chlorine and chlorine + ammonia was investigated over two years in outdoor experimental streams. In 1985, downstream riffles of 2 streams were dosed (observed in-stream concentrations) at ca. 10 μg/L Total Residual Chlorine (TRC), one stream at 64 μg/L TRC and one stream at 230 μg/L TRC. Two control streams were not dosed and the upstream riffles of each stream served as within stream controls. In 1986, the downstream riffle of one stream was dosed at 70 μg/L TRC and a second stream was dosed at 200 μg/L TRC. Four streams were also dosed with 2.5 mg/L NH₃-N: one stream with no chlorine, one stream with ca. 10 μg/L TRC, one with 56 μg/L TRC, and one with 150 μg/L TRC. A seventh stream was dosed for 2 h at 2000 μg/L TRC and 2.5 mg/L ammonia and then allowed to recover (recovery stream). Each year, litter decomposition (degree day k values) was measured during two 35 day trials (Jun–Jul and Aug–Sep). In 1985, when streams were dosed with chlorine alone, decomposition was significantly reduced with the high (230 μg/L TRC) chlorine dose. Downstream decomposition was 27% (Jun–Jul) and 59% (Aug–Sep) of the upstream (control) rate. No other chlorine effects were found during this period. In Jun–Jul 1986, there was significantly lower decomposition in the downstream dosed sites of the 200 μg/L TRC alone stream, the 146 μg/L TRC + ammonia stream and the recovery stream; downstream decay rates were (respectively) 56%, 42% and 64% of the upstream control sites. No other up-down pairs were different in July 1986. In Aug–Sep, all three streams with chlorine + ammonia (6, 56 and 146 μg/L TRC + 2,5 mg/L ammonia) and the 70 μg/L TRC alone stream had significantly lower decomposition rates in the downstream dosed sites. For these streams, downstream decay rates ranged from 46% (high chlorine + ammonia) to 73% (low chlorine + ammonia) of the upstream control rates. No other up-down pairs were different during this trial. Up and downstream sites of the stream dosed with 2.5 mg/L ammonia alone were nearly identical for both trials (< 3% difference). These results indicate that TRC at less than 250 μg/L can significantly reduce litter decomposition and strongly suggest that addition of ammonia to chlorinated water can increase the toxic effect of chlorine. currently at the Department of Fisheries and Wildlife currently at the Department of Fisheries and Wildlife     

Nerve growth factor and neuronal cell death

The regulation of neuronal cell death by the neuronotrophic factor, nerve growth factor (NGF), has been described during neural development and following injury to the nervous system. Also, reduced NGF activity has been reported for the aged NGF-responsive neurons of the sympathetic nervous system and cholinergic regions of the central nervous system (CNS) in aged rodents and man. Although there is some knowledge of the molecular structure of the NGF and its receptor, less is known as to the mechanism of action of NGF. Here, a possible role for NGF in the regulation of oxidant--antioxidant balance is discussed as part of a molecular explanation for the known effects of NGF on neuronal survival during development, after injury, and in the aged CNS.