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1.
mBio ; 14(1): e0333522, 2023 02 28.
Article in English | MEDLINE | ID: mdl-36723077

ABSTRACT

Climate change is a complex problem involving nonlinearities and feedback that operate across scales. No single discipline or way of thinking can effectively address the climate crisis. Teams of natural scientists, social scientists, engineers, economists, and policymakers must work together to understand, predict, and mitigate the rapidly accelerating impacts of climate change. Transdisciplinary approaches are urgently needed to address the role that microorganisms play in climate change. Here, we demonstrate with case studies how diverse teams and perspectives provide climate-change insight related to the range expansion of emerging fungal pathogens, technological solutions for harmful cyanobacterial blooms, and the prediction of disease-causing microorganisms and their vector populations using massive networks of monitoring stations. To serve as valuable members of a transdisciplinary climate research team, microbiologists must reach beyond the boundaries of their immediate areas of scientific expertise and engage in efforts to build open-minded teams aimed at scalable technologies and adoptable policies.


Subject(s)
Climate Change , Policy , Technology
2.
Part Fibre Toxicol ; 17(1): 51, 2020 10 07.
Article in English | MEDLINE | ID: mdl-33023621

ABSTRACT

BACKGROUND: Titanium dioxide (TiO2) is broadly used in common consumer goods, including as a food additive (E171 in Europe) for colouring and opacifying properties. The E171 additive contains TiO2 nanoparticles (NPs), part of them being absorbed in the intestine and accumulated in several systemic organs. Exposure to TiO2-NPs in rodents during pregnancy resulted in alteration of placental functions and a materno-foetal transfer of NPs, both with toxic effects on the foetus. However, no human data are available for pregnant women exposed to food-grade TiO2-NPs and their potential transfer to the foetus. In this study, human placentae collected at term from normal pregnancies and meconium (the first stool of newborns) from unpaired mothers/children were analysed using inductively coupled plasma mass spectrometry (ICP-MS) and scanning transmission electron microscopy (STEM) coupled to energy-dispersive X-ray (EDX) spectroscopy for their titanium (Ti) contents and for analysis of TiO2 particle deposition, respectively. Using an ex vivo placenta perfusion model, we also assessed the transplacental passage of food-grade TiO2 particles. RESULTS: By ICP-MS analysis, we evidenced the presence of Ti in all placentae (basal level ranging from 0.01 to 0.48 mg/kg of tissue) and in 50% of the meconium samples (0.02-1.50 mg/kg), suggesting a materno-foetal passage of Ti. STEM-EDX observation of the placental tissues confirmed the presence of TiO2-NPs in addition to iron (Fe), tin (Sn), aluminium (Al) and silicon (Si) as mixed or isolated particle deposits. TiO2 particles, as well as Si, Al, Fe and zinc (Zn) particles were also recovered in the meconium. In placenta perfusion experiments, confocal imaging and SEM-EDX analysis of foetal exudate confirmed a low transfer of food-grade TiO2 particles to the foetal side, which was barely quantifiable by ICP-MS. Diameter measurements showed that 70 to 100% of the TiO2 particles recovered in the foetal exudate were nanosized. CONCLUSIONS: Altogether, these results show a materno-foetal transfer of TiO2 particles during pregnancy, with food-grade TiO2 as a potential source for foetal exposure to NPs. These data emphasize the need for risk assessment of chronic exposure to TiO2-NPs during pregnancy.


Subject(s)
Nanoparticles/metabolism , Placenta/metabolism , Titanium/metabolism , Female , Humans , Meconium/chemistry , Metal Nanoparticles/analysis , Metal Nanoparticles/toxicity , Models, Biological , Nanoparticles/toxicity , Perfusion , Pregnancy , Titanium/toxicity
3.
Bioresour Technol ; 253: 94-104, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29331827

ABSTRACT

A pilot-scale bioprocess was developed for the production of karlotoxin-enriched extracts of the marine algal dinoflagellate Karlodinium veneficum. A bubble column and a flat-panel photobioreactors (80-281 L) were used for comparative assessment of growth. Flow hydrodynamics and energy dissipation rates (EDR) in the bioreactors were characterized through robust computational fluid dynamic simulations. All cultures were conducted monoseptically outdoors. Bubble column (maximum cell productivity in semicontinuous operation of 58 × 103 cell mL-1 day-1) proved to be a better culture system for this alga. In both reactors, the local EDR near the headspace, and in the sparger zone, were more than one order of magnitude higher than the average value in the whole reactor (=4 × 10-3 W kg-1). Extraction of the culture and further purification resulted in the desired KTXs extracts. Apparently, the alga produced three congeners KTXs: KmTx-10 and its sulfated derivative (sulfo-KmTx-10) and KmTx-12. All congeners possessed hemolytic activity.


Subject(s)
Dinoflagellida , Photobioreactors , Biomass , Hydrodynamics
4.
J Fish Biol ; 80(1): 110-30, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22220893

ABSTRACT

The entire mitochondrial genome of the striped bass Morone saxatilis was sequenced together with the mitochondrial (mt) control regions of the white bass Morone chrysops, white perch Morone americana, yellow bass Morone mississippiensis, spotted seabass Dicentrarchus punctatus, European seabass Dicentrarchus labrax and the Japanese seabass Lateolabrax japonicus. The resultant 17 580 base pair circular genome of M. saxatilis contains 38 genes (13 proteins, 23 transfer RNAs and two ribosomal RNAs) and a control region bordered by the proline and phenylalanine mitochondrial tRNAs. Gene arrangement was similar to other vertebrates, except that the mt-nd6 gene was found within the control region rather than the canonical position between the mt-nd5 and mt-cyb genes. This translocation was found in all the Morone and Dicentrarchus species studied without functional copies or pseudogenes in the ancestral position. In L. japonicus, the mt-nd6 gene was found in the canonical position without evidence of an mt-nd6 gene in the control region. A Bayesian analysis of these and published mt-nd6 sequences from 45 other Perciformes grouped the Morone and Dicentrarchus species monophyletically with a probability of 1·00 with respect to L. japonicus and all other perciforms, and placed the Dicentrarchus species in the basal position. These data reinforce current placement of L. japonicus outside the Moronidae and provide a clear evolutionary character to define this family. The phylogeny of the Moronidae presented here also supports the hypothesis of an anadromous common ancestor to this family that gave rise to the North American estuarine and freshwater species. A series of tandem repeats previously reported in M. saxatilis was found in the control region of all Morone species between the mt-nd6 and mt-rnr1 genes, but not in either Dicentrarchus species, which reinforces the continued use of these two separate genera.


Subject(s)
Bass/classification , Bass/genetics , Genes, Mitochondrial/genetics , NADH Dehydrogenase/genetics , Phylogeny , Translocation, Genetic , Animals , Gene Order , Genome, Mitochondrial , Molecular Sequence Data
5.
Fish Shellfish Immunol ; 32(1): 16-25, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22056499

ABSTRACT

The full-length cDNA (1362 nucleotides, GenBank JF736621) encoding an extracellular copper zinc superoxide dismutase initially isolated from an EST library of the blue crab Callinectes sapidus was characterized using 3' RACE and named Cas-ecCuZnSOD-2. The open reading frame of Cas-ecCuZnSOD-2 contains 203 deduced amino acids with the conserved active catalytic center for copper and zinc binding and the post-translational modification at two putative N-glycosylation and nine phosphorylation sites. Overall, the deduced amino acids of Cas-ecCuZnSOD-2 shared only 35% sequence identity with that of Cas-ecCuZnSOD (GenBank AF264031) which was previously found in C. sapidus, while it showed ∼75% sequence identity to Scylla paramamosain ecCuZnSOD (GenBank FJ774661). The expression profile of Cas-ecCuZnSOD-2 and the other three C. sapidus SODs: ecCuZn, cytMn- and mitMn SODs was largely ubiquitous among the tested tissues obtained from a juvenile female at intermolt: brain, eyestalk ganglia, pericardial organs, and thoracic ganglia complex (nervous system); hepatopancreas (digestive system); heart, artery and hemocytes (circulatory system); gill and antennal gland (excretory system), hypodermis, and Y-organ (endocrine organ). Our study reports, for the first time in the crustaceans, expression analyses for all four Cas-SODs in hemocytes after immune challenges. Crabs challenged with lipopolysaccharides (LPS) injection had a remarkable induction of Cas-ecCuZnSOD-2 expression along with three other SODs in hemocytes, suggesting that Cas-SODs including Cas-ecCuZnSOD-2 are involved in the defense system, possibly innate immunity and immunocompetency of C. sapidus.


Subject(s)
Brachyura/enzymology , Brachyura/immunology , Gene Expression Regulation, Enzymologic , Superoxide Dismutase/genetics , Superoxide Dismutase/metabolism , Up-Regulation , Animals , Cloning, Molecular , Gene Expression Regulation, Enzymologic/drug effects , Hemocytes/enzymology , Lipopolysaccharides/pharmacology , Molecular Sequence Data , Up-Regulation/drug effects
6.
Gynecol Oncol ; 115(3): 382-8, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19773043

ABSTRACT

OBJECTIVES: The aim of this phase II study was to assess the benefits of a weekly administration of topotecan and gemcitabine in patients with ovarian carcinoma having relapsed after platinum/taxane-based first-line chemotherapy. METHODS: Seventy-seven patients with progression of disease /=2 cycles administered). The only major severe toxicity was neutropenia grades 3 (17%) and 4 (6%). Approximately 60% of the patients received the complete schedule of treatment, dose interruptions/delays being mainly due to moderate thrombocytopenia or neutropenia. The objective response rate was 14%, the values for patients having relapsed within 6 (n=30) and 6-12 (n=36) months being 7% and 20%, respectively. Median durations of response were 4.9 and 6.4 months and clinical benefit rates including stabilizations reached 63% and 69% in patients having relapsed within 6 or 6-12 months, respectively. Corresponding median overall survival was 7.5 and 15.6 months. Symptoms and pain were reduced in 64% and 39% of the patients concerned, respectively. CONCLUSION: In early relapse ovarian cancer, weekly combination of gemcitabine and topotecan has a modest objective response rate. However, a high proportion of patients experienced stable disease and symptom control leading to acceptable quality of life.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Ovarian Neoplasms/drug therapy , Adult , Aged , Aged, 80 and over , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Deoxycytidine/administration & dosage , Deoxycytidine/adverse effects , Deoxycytidine/analogs & derivatives , Drug Administration Schedule , Female , Humans , Infusions, Intravenous , Middle Aged , Quality of Life , Topotecan/administration & dosage , Topotecan/adverse effects , Treatment Outcome , Gemcitabine
7.
Dis Aquat Organ ; 84(1): 79-87, 2009 Mar 09.
Article in English | MEDLINE | ID: mdl-19419009

ABSTRACT

Hematodinium sp. is a parasitic dinoflagellate infecting the blue crab Callinectes sapidus and other crustaceans. PCR-based assays are currently being used to identify infections in crabs that would have been undetectable by traditional microscopic examination. We therefore sought to define the limits of quantitative PCR (qPCR) detection within the context of field collection protocols. We present a qPCR assay based on the Hematodinium sp. 18S rRNA gene that can detect 10 copies of the gene per reaction. Analysis of a cell dilution series vs. defined numbers of a cloned Hematodinium sp. 18S rRNA gene suggests a copy number of 10,000 per parasite and predicts a sensitivity of 0.001 cell equivalents. In practice, the assays are based on analysis of 1% of the DNA extracted from 200 microl of serum, yielding a theoretical detection limit of 5 cells ml(-1) hemolymph, assuming that 1 cell is present per sample. When applied to a limited field survey of blue crabs collected in Maryland coastal bays from May to August 2005, 24 of 128 crabs (18.8%) were identified as positive for Hematodinium sp. infection using qPCR. In comparison, only 6 of 128 crabs (4.7%) were identified as positive using traditional hemolymph microscopic examination. The qPCR method also detected the parasite in gill, muscle, heart and hepatopancreas tissues, with 17.2% of the crabs showing infection in at least one of these tissues. Importantly, it is now possible to enumerate parasites within defined quantities of crab tissue, which permits collection of more detailed information on the epizootiology of the pathogen.


Subject(s)
Brachyura/parasitology , Dinoflagellida/isolation & purification , Polymerase Chain Reaction/methods , Animals , Atlantic Ocean , Female , Male , Maryland , Sensitivity and Specificity , Virginia
8.
Cancer Radiother ; 10(4): 185-207, 2006 Jun.
Article in French | MEDLINE | ID: mdl-16917992

ABSTRACT

CONTEXT: The National French Federation of Comprehensive Cancer Centres (FNCLCC) initiated the update of clinical practice guideline for the management of patients with soft tissue sarcoma in collaboration with the French Sarcoma Group (GSF-GETO), specialists from French public universities, general hospitals and private clinics and with the French National Cancer Institute. This work is based on the methodology developed in the "Standards, Options and Recommendations" (SOR) project. OBJECTIVES: To update SOR guidelines for the management of patients with soft tissue sarcoma previously validated in 1995. METHODS: The methodology is based on a literature review and critical appraisal by a multidisciplinary group of experts who define the CPGsaccording to the definitions of the Standards, Options and Recommendations project. Once the guidelines have been developed, they are reviewed by independent reviewers. RESULTS: This article presents the updated recommendations for radiotherapeutic management. The main recommendations are: 1) irradiation before or after surgical treatment is the standard for soft tissue sarcoma of the extremity and uterine sarcoma; 2) no systematic irradiation should be done in case of retroperitoneal sarcoma.


Subject(s)
Lower Extremity/radiation effects , Retroperitoneal Neoplasms/radiotherapy , Sarcoma/radiotherapy , Soft Tissue Neoplasms/radiotherapy , Upper Extremity/radiation effects , Uterine Neoplasms/radiotherapy , Brachytherapy , Female , France , Humans , Lower Extremity/surgery , Neoadjuvant Therapy , Neoplasm Recurrence, Local/radiotherapy , Radiotherapy Dosage , Radiotherapy, Adjuvant , Retroperitoneal Neoplasms/surgery , Sarcoma/surgery , Soft Tissue Neoplasms/surgery , Upper Extremity/surgery , Uterine Neoplasms/surgery
9.
J Steroid Biochem Mol Biol ; 94(5): 395-404, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15876405

ABSTRACT

Sequential hermaphroditism is a common reproductive strategy in many teleosts. Steroid production is known to mediate both the natural and induced sex change, yet beyond this the physiology directing this process has received little attention. Cytochrome P450 aromatase is a key enzyme in the hormonal pathway catalysing the conversion of sex steroids, androgens to oestrogens, and thus is highly relevant to the process of sex change. This study reports the isolation of cDNA sequences for aromatase isoforms CYP19A1 and CYP19A2 from teleost species representing three forms of sexual hermaphroditism: Lates calcarifer (protandry), Cromileptes altivelis (protogyny), and Gobiodon histrio (bi-directional). Deduced amino acid analysis of these isoforms with other reported isoforms from gonochoristic (single sex) teleosts revealed 56-95% identity within the same isoform while only 48-65% identity between isoforms irrespective of species and sexual strategy. Phylogenetic analysis supported this result separating sequences into isoform exclusive clades in spite of species apparent evolutionary distance. Furthermore, this study isolates 5' flanking regions of all above genes and describes putative cis-acting elements therein. Elements identified include steroidogenic factor 1 binding site (SF-1), oestrogen response element (ERE), progesterone response element (PRE), androgen response element (ARE), glucocorticoid response elements (GRE), peroxisome proliferator-activated receptor alpha/retinoid X receptor alpha heterodimer responsive element (PPARalpha/RXRalpha), nuclear factor kappabeta (NF-kappabeta), SOX 5, SOX 9, and Wilms tumor suppressor (WTI). A hypothetical in vivo model was constructed for both isoforms highlighting potential roles of these putative cis-acting elements with reference to normal function and sexual hermaphroditism.


Subject(s)
Aromatase/genetics , Hermaphroditic Organisms , Perciformes/genetics , Sex Determination Processes , Sex Determination Processes/genetics , Animals , Aromatase/classification , Base Sequence , Female , Isoenzymes/classification , Isoenzymes/genetics , Male , Molecular Sequence Data , Perciformes/metabolism , Phylogeny , Sex Determination Processes/enzymology
10.
Gynecol Obstet Fertil ; 33(1-2): 35-8, 2005.
Article in French | MEDLINE | ID: mdl-15752664

ABSTRACT

Small cell carcinoma of the ovary of the hypercalcemic type is a rare tumour, usually lethal and occurring almost exclusively in young patients. In the majority of described cases, signs of this lesion were revealed by the associated hypercalcemia or by virtue of the physical tumour bulk alone. We report the first case of ovarian small cell carcinoma of the hypercalcemic revealed by a severe acute pancreatitis in a 19-year-old patient.


Subject(s)
Carcinoma, Small Cell/diagnosis , Hypercalcemia/etiology , Ovarian Neoplasms/diagnosis , Pancreatitis/complications , Acute Disease , Adult , Carcinoma, Small Cell/complications , Carcinoma, Small Cell/therapy , Fatal Outcome , Female , Humans , Ovarian Neoplasms/complications , Ovarian Neoplasms/therapy , Pancreatitis/diagnosis , Tomography, X-Ray Computed
11.
J Exp Zool ; 290(7): 673-90, 2001 Dec 01.
Article in English | MEDLINE | ID: mdl-11748616

ABSTRACT

The formation of estrogens from androgens in all vertebrates is catalyzed by the "aromatase" complex, which consists of a membrane bound P(450) enzyme, P(450) aromatase (which binds the androgen substrate and inserts an oxygen into the molecule), and a flavoprotein (NADPH-cytochrome P450 reductase). Among vertebrates, the two major sites of aromatase expression are the brain and gonads. Given the importance of estrogen in reptile sex determination, we set out to examine whether P450arom was involved in the initiation and/or stabilization of sex determination in turtles. We examined the expression of aromatase activity in the brain and gonads of two turtle species exhibiting temperature dependent sex determination (TSD), the diamondback terrapin (Malaclemys terrapin), and the common snapping turtle (Chelydra serpentina). Estradiol when applied at stage 14 of the terrapin induces expression of aromatase in the gonad of embryos incubated at male temperatures (26.5 degrees C). The level of expression is similar to that of a normal embryonic ovary. When applied at stage 22, estradiol does not induce aromatase expression in the terrapin. The xenoestrogen, nonylphenol, sex reverses terrapin embryos at 26.5 degrees C. Letrazole, a nonsteroidal aromatase inhibitor, suppresses aromatase activity in the brain at either incubation temperature. Ovotestes are produced by letrazole administration in the terrapin when incubated at 30.5 degrees C. In the snapping turtle at stage 23, gonadal and brain aromatase activity in embryos incubated at female temperatures (30.5 degrees C) is nearly half that exhibited in terrapin embryos at the same temperature. Moreover, letrazole administration suppresses aromatase expression to nearly basal levels. At male incubation temperatures (26.5 degrees ), brain aromatase expression is nearly three times higher than at female temperatures, while gonadal expression levels are nearly one third lower. However, the gonadal expression levels at male temperatures in the snapping turtle are nearly 25 times higher than that found in the terrapin. Estradiol administration elevates this level nearly three fold. These data suggest that is not merely the expression of aromatase that is important for ovarian development, but that the level of expression may be more important.


Subject(s)
Aromatase/biosynthesis , Gene Expression Regulation , Ovary/enzymology , Sex Determination Processes , Sex Differentiation , Testis/enzymology , Turtles/physiology , Animals , Aromatase/analysis , Brain/enzymology , Embryonic Development , Estradiol/pharmacology , Female , Male , Ovary/embryology , Ovary/growth & development , Temperature , Testis/embryology , Testis/growth & development
12.
Biochem Biophys Res Commun ; 288(3): 503-8, 2001 Nov 02.
Article in English | MEDLINE | ID: mdl-11676471

ABSTRACT

This report describes the structure of the 5'-flanking regions of both the CYP19A1 and A2 genes that were isolated from the genome of the zebrafish (Danio rerio). Consensus sequences of three cAMP-responsive elements (CRE), an aryl hydrocarbon-responsive element (AhR/Arnt), a steroidogenic factor 1 (SF-1) site, and a TATA box were observed in the 5'-flanking region of CYP19A1. In contrast, the 5'-flanking region of CYP19A2 was located upstream of an untranslated exon and possessed consensus sequences of a single CRE, an estrogen-responsive element (ERE), a peroxisome proliferator-activated receptor alpha/retinoid X receptor alpha heterodimer-responsive element (PPARalpha/RXRalpha), and a TATA box. Primer extension analysis revealed that the predominant transcription initiation sites for CYP19A1 and A2 transcripts were 28 and 91 bp upstream from the putative translation initiation codon, respectively. These analyses indicate that substantially different regulators, including a variety of environmental xenobiotics, control the expression the two CYP19 genes.


Subject(s)
5' Untranslated Regions/genetics , Aromatase/genetics , Zebrafish/genetics , Animals , Base Sequence , DNA/analysis , Molecular Sequence Data , Transcription, Genetic
13.
J Exp Zool ; 290(5): 439-48, 2001 Sep 15.
Article in English | MEDLINE | ID: mdl-11555851

ABSTRACT

In all species of crocodilians, sex is determined not by genetic mechanisms, but by the temperature at which the egg is incubated. In the American alligator (Alligator mississippiensis) the thermosensitive period (TSP) for sex determination is a 7- to 10-day window within stages 21-24 of development, around the middle third of the incubation period. Treating embryos with estrogen during the TSP produces female offspring, even at male incubation temperatures. Conversely, blocking embryonic estrogen synthesis at female-inducing temperature prevents development of the female phenotype. Therefore, it has been suggested that estrogen plays a role in determination of sex in the alligator. Estrogen is produced from an androgen substrate by cytochrome P450 aromatase (CYP19). If estrogen plays a critical role in sex determination, there should be differences in aromatase expression between embryos at male- and female-producing temperatures during the TSP. Therefore, to address this question, we cloned and characterized the alligator CYP19 cDNA. Based on the sequence information, a quantitative kinetic reverse transcriptase-polymerase chain reaction (TaqMan) assay was designed to measure expression of the alligator aromatase gene in RNA extracted from the gonadal and brain regions of alligator embryos incubated at male- or female-producing temperatures from prior to the TSP through hatching. Aromatase expression was detected in the brain region from the earliest stage tested (stage 20) through hatching. The hypothalamus had significantly higher expression than the forebrain or hindbrain in both male and female embryos. Expression was not significantly different in the gonadal region between embryos at male and female temperatures until after the TSP, when there was a dramatic increase in expression at female temperature. These data indicate that aromatase expression and, thus, estrogen production, are not the initial trigger for sex determination but play an essential role in ovarian differentiation in the alligator. J. Exp. Zool. 290:439-448, 2001.


Subject(s)
Alligators and Crocodiles/genetics , Aromatase/genetics , Embryo, Nonmammalian/enzymology , Amino Acid Sequence , Animals , Base Sequence , Brain/embryology , Brain/enzymology , DNA, Complementary , Estrogens/physiology , Evolution, Molecular , Female , Gene Expression , Male , Molecular Sequence Data , Reverse Transcriptase Polymerase Chain Reaction , Sex Determination Processes , Temperature
14.
J Exp Zool ; 290(5): 475-83, 2001 Sep 15.
Article in English | MEDLINE | ID: mdl-11555854

ABSTRACT

Cytochrome P450 aromatase (CYP19) is the terminal enzyme in the steroidogenic pathway that converts androgens (e.g., testosterone) into estrogens (e.g., estradiol). Regulation of this gene dictates the ratio of androgens to estrogens; therefore, appropriate expression of this enzyme is critical for reproduction as well as being pivotal in sex differentiation for most vertebrates. It is assumed that most vertebrates have a single CYP19 gene that is regulated by multiple tissue-specific promoter regions. However, the zebrafish (Danio rerio) has two genes (CYP19a and CYP19b), each encoding a significantly different protein and possessing its own regulatory mechanism. The primary purpose of this study was to determine the pattern of expression of each of the CYP19 genes in the developing zebrafish. A fluorescent-based method of real-time, quantitative RT-PCR provided the sensitivity and specificity to determine transcript abundance in single embryos/juveniles harvested at days 0 through 41 days post-fertilization (dpf), which encompasses the developmental events of sex determination and gonadal differentiation. CYP19 transcripts could be detected as early as 3 or 4 dpf, (CYP19a and CYP19b, respectively) and peak abundance was detected on day five. In general, the CYP19 genes differed significantly in the ontogeny of their expression. In most cases, the gonadal form of CYP19 (CYP19a) was more abundant than the brain form (CYP19b); however, unlike CYP19a, the pattern of CYP19b expression could be clearly segregated into two populations, suggesting an association with sex differentiation. Pharmacological steroids (ethinylestradiol and 17 alpha-methyltestosterone) enhanced the expression of the CYP19b gene at all three days examined (4, 6, and 10 dpf). These data suggest that the timely and appropriate expression of CYP19 is important in development and that the expression of CYP19b (the "extra-gonadal" form) may be associated with sexual differentiation if not sexual determination. J. Exp. Zool. 290:475-483, 2001.


Subject(s)
Aromatase/genetics , Gene Expression Regulation, Developmental , Gene Expression Regulation, Enzymologic , Zebrafish Proteins/genetics , Animals , Brain/enzymology , Chromosome Mapping , Embryo, Nonmammalian , Gonads/enzymology , Reverse Transcriptase Polymerase Chain Reaction , Sex Determination Processes , Sex Differentiation/genetics , Zebrafish
15.
Comp Biochem Physiol B Biochem Mol Biol ; 128(4): 675-82, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11290449

ABSTRACT

Most studies on chitinase activity in lizards have been concerned with Palaearctic (European) and Laurasian (Middle Eastern and Asian) taxa. Several genera of Old World lizards, Anguis, Uromastix, Chamaeleo and Lacerta, have been shown to possess chitinolytic activity. To date, only one New World lizard, Anolis carolinensis, has been reported to exhibit chitinolytic activity. In the present study, chitinase activity was characterized in a second New World taxon, Sceloporus undulatus garmani, a New World, phrynosomatid lizard. Chitinolytic activity was measured by incubating tissue extracts with a radioactive chitin substrate, acetyl-[H3]chitin and determining acid soluble radioactivity as an estimate for chitin hydrolysis. Chitinolytic activity was present in stomach, small intestine and pancreas extracts, with the stomach and pancreas having the highest specific activities. Chitinolytic activity was higher at pH 4.5 than at pH 7.5. The stomach chitinase is immunologically similar to the gastric chitinase previously described for rainbow trout. Western blot analysis showed anti-chitinase cross-reactivity in the extracts of the stomach, but no cross-reactivity in the pancreatic or intestinal extracts, suggesting different isoforms of chitinase. There was no detected lysozyme activity (less than 0.01 mg/ml lysozyme) present in the extracts of the stomach, small intestine and pancreas. The localization of chitinolytic activity in S. u. garmani is in agreement with earlier reptilian reports on the distribution of chitinase.


Subject(s)
Chitinases/metabolism , Digestive System/enzymology , Lizards/metabolism , Animals , Antibodies , Chitin/metabolism , Chitinases/immunology , Cross Reactions/immunology , Female , Hydrogen-Ion Concentration , Intestine, Small/enzymology , Isoenzymes , Male , Oncorhynchus mykiss , Pancreas/enzymology , Stomach/enzymology , Tissue Distribution , Tritium
16.
Comp Biochem Physiol B Biochem Mol Biol ; 128(2): 285-94, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11207442

ABSTRACT

Blood samples were collected from 26 captive-reared alligators (25 females; one male) and 12 (seven females and five males) wild "nuisance" alligators collected by wildlife personnel in south Louisiana in May 1995. The captive alligators, hatched from artificially incubated eggs in 1972-1973, had received vitamin E supplements during the 3 weeks before the blood sample was collected. Each sample was analyzed for vitamin E (alpha-tocopherol), vitamin A (retinol), total lipid, triacylglycerol, phospholipid, cholesterol, cholesteryl ester, free fatty acids, steroid hormones and a standard clinical blood panel. The fatty acid composition of the plasma lipid fraction was also analyzed. Results indicated that 18 of the captive females and three of the seven wild females were undergoing vitellogenesis, i.e. had elevated plasma estradiol and elevated plasma calcium. Vitellogenic females had higher vitamin E than non-vitellogenic females (77.4 microg/ml vs. 28.6 microg/ml in captive females; 24.0 microg/ml vs. 21 microg/ml in wild females). Plasma retinol was similar in all groups, ranging from 0.5 to 1.4 microg/ml and close to values reported in birds. All lipid fractions, with the exception of cholesteryl ester, were higher in captive alligators than in wild alligators. There were also significant differences in the fatty acid composition of wild and captive alligators. Plasma eicosapentaenoic and docasahexaenoic acid were higher in wild than in captive alligators, whereas linoleic was higher in captive than in wild.


Subject(s)
Fatty Acids/blood , Hyperlipidemias/metabolism , Infertility/metabolism , Lipids/blood , Steroids/blood , Vitamin A/blood , Vitamin E/blood , Alligators and Crocodiles , Animals , Calcium/blood , Chromatography, High Pressure Liquid , Docosahexaenoic Acids/blood , Eicosapentaenoic Acid/blood , Estradiol/blood , Female , Linoleic Acid/blood , Male , Time Factors
17.
J Biol Chem ; 276(9): 6770-8, 2001 Mar 02.
Article in English | MEDLINE | ID: mdl-11085997

ABSTRACT

Chitinases are ubiquitous chitin-fragmenting hydrolases. Recently we discovered the first human chitinase, named chitotriosidase, that is specifically expressed by phagocytes. We here report the identification, purification, and subsequent cloning of a second mammalian chitinase. This enzyme is characterized by an acidic isoelectric point and therefore named acidic mammalian chitinase (AMCase). In rodents and man the enzyme is relatively abundant in the gastrointestinal tract and is found to a lesser extent in the lung. Like chitotriosidase, AMCase is synthesized as a 50-kDa protein containing a 39-kDa N-terminal catalytic domain, a hinge region, and a C-terminal chitin-binding domain. In contrast to chitotriosidase, the enzyme is extremely acid stable and shows a distinct second pH optimum around pH 2. AMCase is capable of cleaving artificial chitin-like substrates as well as crab shell chitin and chitin as present in the fungal cell wall. Our study has revealed the existence of a chitinolytic enzyme in the gastrointestinal tract and lung that may play a role in digestion and/or defense.


Subject(s)
Chitinases/metabolism , Hexosaminidases/metabolism , Amino Acid Sequence , Animals , Base Sequence , Chitinases/chemistry , Chitinases/genetics , DNA, Complementary/chemistry , Hexosaminidases/chemistry , Hexosaminidases/genetics , Humans , Hydrogen-Ion Concentration , Isoelectric Point , Mice , Molecular Sequence Data , Molecular Weight , RNA, Messenger/analysis , Species Specificity
18.
Lipids ; 35(11): 1269-80, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11132186

ABSTRACT

The extent to which extreme dietary levels of arachidonate (AA) and/or docosahexaenoate (DHA) modulate lipid composition in the body tissues and consequently affect growth and survival in freshwater Morone larvae species was examined. White bass, M. chrysops, larvae (day 24-46) were fed Artemia nauplii enriched with algal oils containing varying proportions of AA and DHA (from 0 to over 20% the total fatty acids). Growth was significantly reduced (P< 0.05) in larvae fed a DHA-deficient Artemia diet. Increases in dietary levels of AA also were associated with a significant growth reduction. However, the inhibitory effect of AA on larvae growth could be suppressed by the dietary addition of DHA (at a level of 21.6% of the total fatty acids in enrichment lipids). Larval brain + eyes tissue accumulated over 10 times more DHA than AA in its structural lipids (phosphatidylcholine, phosphatidylethanolamine) at any dietary ratio. In contrast, DHA accumulation, as compared to AA, in gill lipids declined considerably at higher than 10:1 DHA/AA tissue ratios. DHA and eicosapentaenoic acid (EPA) contents in brain + eyes tissue were most sensitive to competition from dietary AA, being displaced from the tissue at rates of 0.36 +/- 0.07 mg DHA and 0.46 +/- 0.11 mg EPA per mg increase in tissue AA, and 0.55 +/- 0.14 mg AA per mg increase in tissue DHA. On the other hand, AA and EPA levels in gill tissue were most sensitive to dietary changes in DHA levels; AA was displaced at rates of 0.37 +/- 0.11 mg, whereas EPA increased at rates of 0.68 +/- 0.28 mg per mg increase in tissue DHA. Results suggest that balanced dietary DHA/AA ratios (that allow DHA/AA ratios of 2.5:1 in brain + eyes tissue) promote a high larval growth rate, which also correlates with maximal regulatory response in tissue essential fatty acids.


Subject(s)
Arachidonic Acid/metabolism , Bass/growth & development , Docosahexaenoic Acids/metabolism , Larva/metabolism , Animals , Arachidonic Acid/administration & dosage , Dietary Fats, Unsaturated/administration & dosage , Docosahexaenoic Acids/administration & dosage
19.
Cell Growth Differ ; 11(5): 261-7, 2000 May.
Article in English | MEDLINE | ID: mdl-10845427

ABSTRACT

The oleanane triterpenoid 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO) is a multifunctional molecule that induces growth inhibition and differentiation of human myeloid leukemia cells. The present studies demonstrate that CDDO treatment results in apoptosis of U-937 and HL-60 myeloid leukemia cells. Similar to 1-beta-D-arabinofuranosylcytosine (ara-C), another agent that inhibits growth and induces apoptosis of these cells, CDDO induced the release of mitochondrial cytochrome c and activation of caspase-3. Overexpression of Bcl-X(L) blocked cytochrome c release, caspase-3 activation, and apoptosis in ara-C-treated cells. By contrast, CDDO-induced release of cytochrome c, and activation of caspase-3 were diminished only in part by Bcl-X(L). In concert with these findings, we demonstrate that CDDO, but not ara-C, activates caspase-8 and thereby caspase-3 by a cytochrome c-independent mechanism. The results also show that CDDO-induced cytochrome c release is mediated by caspase-8-dependent cleavage of Bid. These findings demonstrate that CDDO induces apoptosis of myeloid leukemia cells and that this novel agent activates an apoptotic signaling cascade distinct from that induced by the cytotoxic agent ara-C.


Subject(s)
Apoptosis/drug effects , Caspases/metabolism , Leukemia, Myeloid , Oleanolic Acid/analogs & derivatives , Antimetabolites, Antineoplastic/pharmacology , Caspase 3 , Caspase 8 , Caspase 9 , Cell Differentiation/drug effects , Cell Division/drug effects , Cytarabine/pharmacology , DNA Fragmentation/drug effects , HL-60 Cells , Humans , Oleanolic Acid/pharmacology , Proto-Oncogene Proteins c-bcl-2/biosynthesis , Signal Transduction/drug effects , Signal Transduction/physiology , U937 Cells , bcl-X Protein
20.
Eur J Obstet Gynecol Reprod Biol ; 91(1): 51-7, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10817879

ABSTRACT

Four main clinicopathologic features of neuroendocrine tumors (NETs) of the cervix may be stressed: primary diagnosis at an advanced stage, early nodal metastasis even for low disease, early failure of appropriate local treatment (surgery and/or radiation therapy) and aggressive clinical treatment. Five patients with NET of the uterine cervix (small cell carcinoma type) are reported (one stage I, two stages II, one stage III and one stage IV). One patient was treated by surgery combined with radiation therapy, one by surgery combined with chemotherapy and one by surgery with radiation therapy and chemotherapy. Two patients received radiation therapy alone. Three early stage patients are alive with no evidence of disease 8, 26 and 41 months after diagnosis. The two patients with advanced stage died of disease, 3 and 12 months respectively, after diagnosis. Combination chemotherapy (cisplatin and etoposide) is warranted in disseminated NETs. Neoadjuvant or adjuvant chemotherapy should be combined with radiation therapy and surgery even in early stages.


Subject(s)
Neuroendocrine Tumors/pathology , Uterine Cervical Neoplasms/pathology , Adult , Aged , Aged, 80 and over , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Small Cell/pathology , Carcinoma, Small Cell/therapy , Combined Modality Therapy , Female , Humans , Hysterectomy/methods , Middle Aged , Neuroendocrine Tumors/drug therapy , Neuroendocrine Tumors/radiotherapy , Uterine Cervical Neoplasms/therapy
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