The caudal fin of adult zebrafish is used to study the molecular mechanisms that govern regeneration processes. Most reports of gene expression in regenerating caudal fins rely on in situ hybridization (ISH) on whole-mount samples followed by sectioning of the samples. In such reports, expression is mostly confined to cells other than those located between the dense collagenous structures that are the actinotrichia and lepidotrichia. Here, we re-examined the expression of genes by performing ISH directly on cryo-sections of regenerates. We detected expression of some of these genes in cell types that appeared to be non-expressing when ISH was performed on whole-mount samples. These results demonstrate that ISH reagents have a limited capacity to penetrate between the regenerating skeletal matrices and suggest that ISH performed directly on fin sections is a preferable method to study gene expression in fin regenerates. Developmental Dynamics 237:417-425, 2008.

A quantitative ethnobotanical approach to antimalarial drug discovery led to the identification of Lansium domesticum Corr. Ser. (Meliaceae) as an important antimalarial used by Kenyah Dyak healers in Indonesian Borneo. Triterpenoid lansiolides with antimalarial activity were isolated from the bark and shown to have activity in both in vitro bioassays with Plasmodium falciparum, and in mice infected with P. berghei. A survey of African and tropical American Meliaceae led to further development of the limonoid gedunin from the traditionally used medicinal plants, tropical cedar, Cedrela odorata L., and neem, Azadirachta indica A. Juss. Gedunin has significant in vitro activity but initially showed poor in vivo activity. In vivo activity was improved by (1) incorporation into an easy to absorb suspension, (2) preparation of a more stable compound, 7-methoxygedunin; and (3) synergism with dillapiol, a cytochrome P450 3A4 inhibitor. The results show the potential for both antimalarial drug and phytomedicine development from traditionally used plants.

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Background Rates of contralateral prophylactic mastectomy (cpm) continue to rise internationally despite evidence-based guidance strongly discouraging its use in most women with unilateral breast cancer. The purpose of the present study was to develop and assess the feasibility of a knowledge translation tool [a patient decision aid (da)] designed to enhance evidence-informed shared decision-making about cpm.Methods A consultation da was developed using the Ottawa Patient Decision Aid Development eTraining in consultation with clinicians and knowledge translation experts. The final da was then assessed for feasibility with health care professionals and patients across Canada. The assessment involved a survey completed online (health care professionals) or by telephone (patients). Survey data were analyzed using descriptive statistics for closed-ended questions and qualitative content analysis for open-ended questions.Results The 51 participants who completed the survey included 39 health care professionals and 12 patients. The da was acceptable; 88% of participants viewed it as having the right amount of information or slightly more or less information than they would like. Almost all participants (98%) felt that the da would prepare patients to make better decisions. The aid was perceived to be usable, with 73% of participants stating that they would be willing to use or share the da.Conclusions The cpm patient da developed for the present study was viewed by health care professionals and patients across Canada to be acceptable and usable during the clinical consultation. It holds promise as a knowledge translation tool to be used by clinicians in consultation with women who have unilateral breast cancer to enhance evidence-informed and shared decision-making with respect to undergoing cpm.

The effect of epinephrine (10(-7) M) on cytosolic free-Ca2+ concentration ([Ca2+]i) and its dependency on external Ca2+ were studied in fura-2-loaded hepatocytes isolated from three teleost fish species: American eel, brown bullhead, and rainbow trout. Basal [Ca2+]i was similar in eel and trout hepatocytes (79.6 +/- 14.6 and 75.7 +/- 17.4 nM, respectively) but was significantly higher in bullhead cells (184 +/- 23 nM). Epinephrine-induced [Ca2+]i oscillations were observed only in eel hepatocytes. These oscillations, which presented variable patterns among individual cells, also developed in the absence of external Ca2+, although their amplitude progressively declined to eventually vanish under such conditions. In bullhead hepatocytes, epinephrine induced a biphasic [Ca2+]i response, with an initial transient rise followed by a sustained component; this response was virtually abolished in the absence of extracellular Ca2+. The peak [Ca2+]i achieved (433.5 +/- 135.6 nM) was more than two times that of eel cells (184.3 +/- 30 nM) but represented a similar percent increase above control [Ca2+]i for both species. Rainbow trout hepatocytes, contrary to eel and bullhead cells, demonstrated little epinephrine sensitivity, with less than 20% of the cells responding. These data clearly point to significant species differences both in terms of epinephrine-induced changes in [Ca2+]i and in the dependence of these transients on external Ca2+. Thus the eel response relies primarily on intracellular stores, whereas the bullhead response principally involves enhanced influx of Ca2+ from the extracellular milieu. Furthermore, the similarity of these responses with those reported for mammalian hepatocytes strongly suggests that an alpha-adrenoceptor/Ca2+ transduction system is involved in at least eel and bullhead hepatocytes.

Viable Atlantic hagfish (Myxine glutinosa) hepatocytes were isolated from combined or separated large and small lobes and carbohydrate metabolism was studied. Cells had low levels of glycogen (16-30 μmol·g(-1)), and low rates of total glucose production (TGP; 0-480 nmol·h(-1)·g(-1) cells). Lactate flux to glucose (5.5 nmol·h(-1)·g(-1)) and CO2 (76 nmol·h(-1)·g(-1)) was lower than reported values for teleosts, with a low percentage (30%) of the lactate carbon reaching glucose. Insulin significantly increased total glucose production and gluconeogenesis and decreased 6-phosphofructo 1-kinase (PFK-1) activities and glucose oxidation, while glucagon was without effect on any parameter studied. Forskolin significantly increased TGP. Epinephrine (Epi), norepinephrine (NEpi), isoproterenol (Iso), and phenylephrine (Phe) all decreased CO2 production from lactate; propanolol blocked the effects of Epi, NEpi, and Iso. The large lobe, accounting for 65% of total liver mass, had a higher glycogen content and higher CO2 production from lactate compared to the small lobe. Furthermore, enzyme activities in the large lobe were greater than in the small lobe, with the exception of glycogen phosphorylase (GPase) which exhibited smaller %a values in the large lobe. These data indicate the presence of a hormonally-responsive carbohydrate metabolism in hagfish hepatocytes, which is qualitatively and quantitatively different between the two liver lobes.

Previous studies have reported very low rates of gluconeogenesis from lactate in sea raven (Hemitripterus americanus) hepatocytes compared to other teleosts studied. This study examines whether hepatic cell redox or lactate dehydrogenase (LDH) characteristics may explain this observation. Sea raven hepatic optimal LDH activities (pyruvate reductase direction) were more than 40 times less compared with rainbow trout liver values (40 vs 1914 μmol·min(-1)·g(-1) protein). The Km(lactate) was 9.24 and 0.86 mM for sea raven and trout hepatic LDH, but the Km(pyruvate) was similar between the two species (0.11 and 0.21 mM, respectively). These results suggested that sea raven liver LDH did not favour lactate use and was more indicative of the mammalian M-isozyme. Gel electrophoresis showed a predominant intermediate isozyme, with a small amount of the M-type LDH. Phosphoenolpyruvate carboxykinase (PEPCK) was localized to the mitochondrial compartment, while there was no apparent mitochondrial glutamate-oxaloacetate transaminase (GOT) activity. No in vitro lactate flux to glucose was found in untreated, 10 mM ethanol-treated, or 3 mM NH4Cl-treated sea raven hepatocytes, although CO2 production from lactate was decreased by ethanol and increased by NH4Cl. These results provide evidence that cell redox does not limit gluconeogenesis from lactate, while low activities and the kinetic characteristics of LDH may partially explain the low lactate gluconeogenesis reported in sea raven hepatocytes.

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