Long-term effect of temperature on bioaccumulation of dietary metals and metallothionein induction in Sparus aurata

Previous studies have demonstrated that the commercial feed of aquacultured fish contains trace amounts of toxic and essential metals which can accumulate in tissues and finally be ingested by consumers. Recently rising temperatures, associated to the global warming phenomenon, have been reported as a factor to be taken into consideration in ecotoxicology, since temperature-dependent alterations in bioavailability, toxicokinetics and biotransformation rates can be expected. Sparus aurata were kept at 22 °C, 27 °C and 30 °C for 3 months in order to determine the temperature effect on metallothionein induction and metal bioaccumulation from a non-experimentally contaminated commercial feed. A significant temperature-dependent accumulation of cadmium (Cd), copper (Cu), mercury (Hg), zinc (Zn), lead (Pb) and iron (Fe) was found in liver, together with that of manganese (Mn), Fe and Zn in muscle. Hg presented the highest bioaccumulation factor, and essential metal homeostasis was disturbed in both tissues at warm temperatures. An enhancement of hepatic metallothionein induction was found in fish exposed to the highest temperature.     

Ultrastructure of the spermatozoa of Hymenosomatidae (Crustacea: Brachyura) and the relationships of the family

The spermatozoa of the genus Odiomaris Ng and Richer de Forges, 1996 (=Amarinus Lucas, 1980) have the components typical of eubrachyuran (Heterotremata + Thoracotremata) sperm, but differ significantly from all other investigated eubrachyurans in at least ten characteristics: (1) presence of an epiopercular dome; (2) separation of all but the central region of the operculum from the remainder of the acrosome by an infra-opercular rim; (3) the fact that the acrosome is smaller in volume than the nucleus; (4) the acrosome is strongly emergent from the nucleus, being surrounded only basally by nuclear material; (5) the cytoplasmic sheath, ending anteriorly with the nucleus, is also basal; (6) division of the acrosome contents into an inner and outer acrosome zone is scarcely apparent in longitudinal section as the inner zone is narrow and of doubtful homology; (7) the thin, putative inner acrosome zone is anteriorly almost septate owing to several longitudinal corrugations; (8) basally there is a unique “fringe zone”; (9) the acrosome, including the epinuclear dome, is longer than wide; (10) the unique helical and posterolateral disposition of the nuclear arms. From a purely spermatological viewpoint, Odiomaris (as exemplified by O. pilosus and O. estuarius), and provisionally the Hymenosomatidae, are thus excluded from the Thora- cotremata, in which they were formerly placed, nor are they readily placeable in the Heterotremata. Received: 30 December 1996 / Accepted: 4 February 1997     

Evaluation on exposures to particulate matter at a junior secondary school: a comprehensive study on health risks and effective inflammatory responses in Northwestern China

Air pollutant measurement and respiratory inflammatory tests were conducted at a junior secondary school in Xi’an, Northwestern China. Hazardous substances including particulate matters (PMs), black carbon (BC) and particle-bounded polycyclic aromatic hydrocarbons (PAHs) were quantified both indoors and outdoors of the school. Source characterization with organic tracers and particle-size distribution demonstrated that the school’s air was mostly polluted by combustion emissions from the surrounding environment. The evaluation of health assessment related to air quality was conducted by two methods, including potential risk estimation of air pollutants and direct respiratory inflammatory test. The incremental lifetime cancer risks associated with PAHs were estimated and were 1.62 × 10⁻⁶ and 2.34 × 10⁻⁶, respectively, for indoor and outdoor fine PMs. Both the values exceeded the threshold value of 1 × 10⁻⁶, demonstrating that the carcinogenic PAHs are a health threat to the students. Respiratory inflammatory responses of 50 students who studied in the sample classroom were examined with a fractional exhaled nitric oxide (FeNO) test, with the aid of health questionnaires. The average FeNO concentration was 17.4 ± 8.5 ppb, which was slightly lower than the recommended level of 20 ppb established by the American Thoracic Society for children. However, a wide distribution and 6% of the values were > 35 ppb, suggesting that the potentials were still high for eosinophilic inflammation and responsiveness to corticosteroids. A preliminary interpretation of the relationship between air toxins and respiratory inflammatory response demonstrated the high exposure cancer risks and inflammatory responses of the students to PMs in the city.

     

Podotreme affinities of Raninoides sp. and Lyreidus brevifrons: evidence from spermatozoal ultrastructure (Crustacea: Brachyura: Raninoidea)

Spermatozoal synapomorphies which singly or collectively distinguish Raninoidea are: (1) the presence of single (Ranina, Raninoides) or multiple (Lyreidus) keel-like projections of the acrosomal capsule; (2) a very large, weakly electron-opaque peripheral acrosomal zone (Ranina, Raninoides) and an homologous large outer zone in Lyreidus; (3) poor differentiation of the operculum from the capsule (autapomorphy); (4) a very well developed, perforate subopercular zone, of variable form; (5) presence of unique inward longitudinal projections (septa or corrugations) in the wall of the subacrosomal chamber (autapomorphy). Shared, presumably synapomorphic characters of Ranina and Raninoides but not of Lyreidus within the Raninidae, are: (1) branching of some of the subacrosomal septa (unbranched in Lyreidus); (2) the subspheroidal form of the acrosome in Ranina with a length: width ratio (L:W) of 0.76, and, although slightly more depressed, in Raninoides (L:W 0.73), considered apomorphic relative to the more depressed form in Lyreidus (L:W 0.52); (3) single or multiple coiled perforatorial filaments (Ranina, Raninoides) contrasting with a capitate perforatorium with “amoeboid” head in Lyreidus; (4) division of the capsule wall to give one posterior (Ranina) or multiple enclaves, plesiomorphically (?) absent in Lyreidus. Similarities of Lyreidus with other podotremes include the capitate perforatorium, questionably related to the radiate spiked-wheel structure of homolids in which acrosome proportions are similar or less closely to the bilateral capitate perforatorium of dromiids and dynomenids, and basal capsular projections as in the dromiid Stimdromia (=Petamolera) lateralis and in cyclodorippoids. No spermatozoal synapomorphies support a sister-group relationship of raninoids and heterotreme-thoracotreme crabs.