Norman Y. S. Woo

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There is increasing concern that certain chemicals in the aquatic environment can disrupt endocrine systems, leading to reproductive impairment and threatening survival of wild populations of invertebrates, fish, bird, reptiles, and wildlife. For the first time, we report that hypoxia is also an endocrine disruptor and poses a significant threat to the(More)
Certain fish have the remarkable capability of euryhalinity, being able to withstand large variations in salinity for indefinite periods. Using the highly euryhaline species, silver sea bream (Sparus sarba), as an experimental model, some of the molecular processes involved during ion regulation (Na+-K+-ATPase), cytoprotection [heat shock protein (hsp) 70],(More)
Recent studies have indicated that ghrelin stimulates growth hormone release from the pituitary via the growth hormone secretagogue receptor (GHSR). We have previously isolated two GHSR subtypes from the pituitary of the black seabream Acanthopagrus schlegeli. In the present study, we have cloned and characterized ghrelin from the same fish species at both(More)
A total of 51 potential pathogenic vibrios were isolated from moribund silver seabream Sparus sarba, which were collected from local fish farms of Hong Kong. All the isolates were classified and identified as 7 species by the API 20 E system and the scheme of Alsina & Blanch. These species were Vibrio alginolyticus (24 strains), Vibrio vulnificus (12(More)
The genes encoding heat shock cognate 70 (hsc70) and inducible heat shock protein 70 (hsp70) were cloned and characterized from silver sea bream liver. Upon acute heat shock (+7 degrees C), the transcript abundance of hsc70 was increased 1.7-fold whereas the transcript abundance of hsp70 increased 6.7-fold. The chronic acclimation of sea bream to cold(More)
The rates of glycogenesis, glycogenolysis, lipogenesis and lipolysis were determined in selected tissues of the coho salmon, Oncorhynchus kisutch, during the period of parr-smolt transformation between February 1983 and June 1983. Glycogen synthesis in the liver, measured by uridine diphosphate formation, decreased 54% from initial levels. Liver glycogen(More)
The focus of this review is on the importance and regulation of fish growth hormone (GH), during exposure to stress. Alterations in environmental salinity impose osmoregulatory stress on fish and upon exposure to increased salinities GH has been shown to be important in maintaining hypoosmoregulatory function. Whilst studies mainly on salmonids, demonstrate(More)
Heat shock protein 70 (HSP70) expression was assessed in hepatic tissue of a marine teleost Sparus sarba after exogenous hormone administration. Using a PCR-amplified, homologous HSP70 cDNA clone, as a probe in Northern analysis, we detected a 2.3 kb transcript which was elevated after exposure to a temperature 7 degrees C above the ambient. For our studies(More)
The effect of hormone treatment on the abundance of Na+-K+-ATPase alpha- and beta-subunit mRNA in Sparus sarba branchial tissue was investigated. Groups of seawater (33/1000) and hypo-osmotic (6/1000) acclimated fish were injected daily, with either saline, cortisol, recombinant bream growth hormone (rbGH) or ovine prolactin (oPRL). Total RNA from branchial(More)