MARIJUANA AND REPRODUCTION - EFFECTS ON PUBERTY AND PREGNANCY IN FEMALE RATS - EXPERIMENTAL RESULTS
Source: ANNALES D ENDOCRINOLOGIE Volume: 53 Issue: 1 Pages: 37-43 Published: 1992
Abstract: The main psychoactive component of marihuana, delta-9-tetrahydrocannabiol (THC), was investigated at low doses (1-mu-g/kg/day) on the onset of puberty, on the reproductive functions in female rats up to the seventy fifth to eightieth day of life as well as during the pregnancy.
The administration of THC caused a delay of the onset of puberty, and the number of ova on the day of first estrus was significantly lower in treated animals.
After puberty, alterations occured in the neuroendocrine functions of animals received THC: estrous cycles were irregular, serum LH level was decreased.
When THC was injected during the third week of pregnancy it caused a significant prolongation of the gestation period. There was 30 % stillbirths (v.s. 3 % in physiological saline treated rats). No teratological effects were observed. Serum LH, progesterone and prostaglandin contents were decreased.
The results indicate that marihuana causes alterations in reproductive functions. The importance of fight against drug abuse is emphasized.
Document Type: Article
Language: French
KeyWords Plus: DELTA-9 TETRAHYDRO-CANNABINOL; ADULT MALE-RATS; LUTEINIZING-HORMONE; SERUM LH; DELTA-9-TETRAHYDROCANNABINOL; ENDOCRINE; EXPOSURE; ALCOHOL; FSH
Reprint Address: WENGER, T (reprint author), FAC MED BUDAPEST, ANAT LAB 2, BUDAPEST, HUNGARY
Addresses:
1. FAC MED LILLE, HISTOL EMBRYOL & BIOL REPROD LAB, F-59045 LILLE, FRANCE
2. UNIV BORDEAUX 1, NEUROCYTOCHIM FONCTIONNELLE LAB, F-33405 TALENCE, FRANCE
3. INSERM, U156, F-59045 LILLE, FRANCE
Publisher: MASSON EDITEUR, 120 BLVD SAINT-GERMAIN, 75280 PARIS 06, FRANCE
Subject Category: Endocrinology & Metabolism
IDS Number: JA805
ISSN: 0003-4266
Tuesday, October 7, 2008
Saturday, August 16, 2008
Tuesday, August 5, 2008
Suberin: waxy, waterproof chemical in some plant cells, notably cork (in stems) and endodermis cells (in roots). Suberin is an extremely complex and irregular material, like lignin -- with which it shares some similarities. Suberin is composed of two physically separated domains: the aliphatic and phenolic. The phenolic domain is rather lignin-like, but with even greater variability, and built on the same basic unit of a di- or tri-hydroxyphenyl group attached to a three-carbon chain, variously oxidized and integrated with the carbohydrates of the cell walls. Perhaps the most common building block is ferulic acid: formally, 3-(2'-methoxy-3'-hydroxyphenyl)-propenoic acid. Distally, the phenolic domain is attached at points by ester linkages to glycerol. The remaining hydroxyls of the glycerol molecule are ester-linked to some strange-looking C-18 to C-30 lipids. These lipids are substituted at C9-10 with one or two hydroxyls, or even with an epoxide link between the two carbons. Finally the ω- position may be oxidized to a carboxylate (alone or esterized to glycerol) or hydroxyl (alone or esterised to ferulic acid). Variations allow for cross-linkage to other suberin molecules via the 9-10 or ω positions. Image adapted from Bernards (2002).
Suberin is a plant cell wall modification that involves the deposition of both a poly(phenolic) and a poly(aliphatic) domain within the same tissue. As such, the deposition of suberin represents the coordinate regulation of both fatty acid metabolism (giving rise to suberin-specific aliphatic compounds) and phenylpropanoid metabolism (givin rise to suberin-specific phenolic compounds). Over the past decade, we have used chemical analyses to identify target metabolites unique to suberin and biochemical analyses to identify unique steps in their biosynthesis. We are now in a position to clone and characterize the genes that encode the enzymes for these unique biochemical steps. With these genes in hand, we will be able to ask questions about the regulation of suberization and study the mechanism(s) by which disparate pathways converge to make the unique material known as suberin.
In addition, we are interested in the role(s) for which plants use secondary metabolites to interact with other organisms. Recently, we have focused on the role of ginsenosides (e.g., Rb1 at right) in the interaction between ginseng and one of its major pathogens, Pythium irregulare.
Our research group is located on the fourth floor of the North Campus Building, forming part of the Environmental Stress Biology Group. Other members of the ESBG include Dr. Norman Huner, Dr. Denis Maxwell and Dr. Charlie Trick.
Monday, July 28, 2008
Dyeing the cross-sections for lignin
Dyeing the cross-sections
2 - Phloroglucinol/HCl is used to dye lignified cell walls red
Phloroglucinol/HCl (figure 2) is used to dye lignified cell walls red. This dye works best for herb-chronology because it pronounces the structures you are interested in (the vessels and lignified parenchyma that often adds to the visualization of growth rings in the roots). To prepare the dye dissolve 1-2 points of a spattle of the phenol derivative phloroglucinol (also known as phloroglucin) in 20 ml of 75% alcohol. Use HCl conc. (≥32%) as the other reagent. Using dropper bottles you first apply one drop of phloroglucinol/EtOH to the cutting and, after 5-10 seconds or so, add one drop of HCl. In most cases this produces instantaneous reddish colouring of the lignified tissue. For thin cuttings where only the vessels are lignified colouring may take a little while. In this case do not take the photographs too quickly or you might end up with photos of low contrast. To help speed up colouring you might add a second drop of HCl. On the other hand, thicker cuttings or those that have a lignified parenchyma may colour quickly and deeply so that you should take the photo quickly to prevent dark photographs. In this case you should reduce the amounts of dye applied to the cuttings. If you do not produce satisfactory colouring try to add some more phloroglucinol to the alcoholic solution.
2 - Phloroglucinol/HCl is used to dye lignified cell walls red
Phloroglucinol/HCl (figure 2) is used to dye lignified cell walls red. This dye works best for herb-chronology because it pronounces the structures you are interested in (the vessels and lignified parenchyma that often adds to the visualization of growth rings in the roots). To prepare the dye dissolve 1-2 points of a spattle of the phenol derivative phloroglucinol (also known as phloroglucin) in 20 ml of 75% alcohol. Use HCl conc. (≥32%) as the other reagent. Using dropper bottles you first apply one drop of phloroglucinol/EtOH to the cutting and, after 5-10 seconds or so, add one drop of HCl. In most cases this produces instantaneous reddish colouring of the lignified tissue. For thin cuttings where only the vessels are lignified colouring may take a little while. In this case do not take the photographs too quickly or you might end up with photos of low contrast. To help speed up colouring you might add a second drop of HCl. On the other hand, thicker cuttings or those that have a lignified parenchyma may colour quickly and deeply so that you should take the photo quickly to prevent dark photographs. In this case you should reduce the amounts of dye applied to the cuttings. If you do not produce satisfactory colouring try to add some more phloroglucinol to the alcoholic solution.
"The Fungal Kingdom: Diverse and Essential Roles in Earth's Ecosystem," June 2008
"The Fungal Kingdom: Diverse and Essential Roles in Earth's Ecosystem," (June 2008)
Prepared by Arturo Casadevall, Joe Heitman, and Merry Buckley
Fungi can cause a number of life-threatening diseases but they also are becoming increasingly useful to science and manufacturing every year. However, many people, scientists among them, are largely unaware of the roles fungi play in the world around us. Research on fungi and fungal diseases are seriously neglected as a result – a situation with grave negative repercussions for human health, agriculture, and the environment. The Fungal Kingdom explores the roles fungi play in the world around us.
http://www.asm.org/ASM/files/ccLibraryFiles/Filename/000000004018/Fungal_Kingdom.pdf
Prepared by Arturo Casadevall, Joe Heitman, and Merry Buckley
Fungi can cause a number of life-threatening diseases but they also are becoming increasingly useful to science and manufacturing every year. However, many people, scientists among them, are largely unaware of the roles fungi play in the world around us. Research on fungi and fungal diseases are seriously neglected as a result – a situation with grave negative repercussions for human health, agriculture, and the environment. The Fungal Kingdom explores the roles fungi play in the world around us.
http://www.asm.org/ASM/files/ccLibraryFiles/Filename/000000004018/Fungal_Kingdom.pdf
Wednesday, July 23, 2008
Prehistoric mystery organism verified as giant fungus
Prehistoric mystery organism verified as giant fungus
‘Humongous fungus’ towered over all life on land
April 23, 2007
Scientists at the University of Chicago and the National Museum of Natural History in Washington, D.C., have produced new evidence to finally resolve the mysterious identity of what they regard as one of the weirdest organisms that ever lived.
Their chemical analysis indicates that the organism was a fungus, the scientists report in the May issue of the journal of Geology, published by the Geological Society of America. Called Prototaxites (pronounced pro-toe-tax-eye-tees), the organism went extinct approximately 350 million years ago.
Prototaxites has generated controversy for more than a century. Originally classified as a conifer, scientists later argued that it was instead a lichen, various types of algae or a fungus. Whatever it was, it stood in tree-like trunks more than 20 feet tall, making it the largest-known organism on land in its day.
“No matter what argument you put forth, people say, well, that’s crazy. That doesn’t make any sense,” said C. Kevin Boyce, an Assistant Professor in Geophysical Sciences at Chicago. “A 20-foot-tall fungus doesn’t make any sense. Neither does a 20-foot-tall algae make any sense, but here’s the fossil.”
The Geology paper adds a new line of evidence indicating that the organism is a fungus. The fungus classification first emerged in 1919, with Francis Hueber of the National Museum of Natural History in Washington, D.C., reviving the idea in 2001. His detailed studies of internal structure have provided the strongest anatomical evidence that Prototaxites is not a plant, but a fungus.
“Fran Hueber has contributed more to our understanding of Prototaxites than anyone else, living or dead,” said Carol Hotton, also of the National Museum of Natural History. “He built up a convincing case based on the internal structure of the beast that it was a giant fungus, but agonized over the fact that he was never able to find a smoking gun in the form of reproductive structures that would convince the world that it was indeed a fungus,” Hotton said.
Co-authoring the Geology paper with Boyce, Hotton and Hueber himself were Marilyn Fogel, George Cody and Robert Hazen of the Carnegie Institution of Washington, and Andrew Knoll of Harvard University. Their work was funded by NASA’s Astrobiology Institute and by the American Chemical Society Petroleum Fund.
Prototaxites lived worldwide from approximately 420 million to 350 million years ago. During this period, which spans part of the Silurian and Devonian periods of geologic time, terrestrial Earth looked quite alien in comparison to the modern world.
Simple vascular plants, the ancestors of the familiar conifers, ferns and flowering plants of today, began to diversify on land during the Devonian Period. “Initially, they’re just stems. They don’t have roots. They don’t have leaves. They don’t have anything like that,” Boyce said.
Millipedes, wingless insects and worms were among the other organisms making a living on land by then, but no backboned animals had yet evolved out of the oceans. “That world was a very strange place,” Boyce said.
Although vascular plants had established themselves on land 40 million years before the appearance of Prototaxites, the tallest among them stood no more than a couple feet high. By the end of the Devonian, approximately 345 million years ago, large trees, ferns, seeds, leaves and roots had all evolved. “They’re all there. They just exploded over this one time period,” Boyce said.
Canadian paleontologist Charles Dawson published the first research on Prototaxites in 1859, based on specimens found along the shores of Gaspé Bay in Quebec, Canada. Hueber pored through Dawson’s field notebooks, written “in a completely illegible scrawl,” Hotton said.
“Fran spent months deciphering them for clues about the localities where specimens had been collected, how Dawson interpreted them and other information that helped understand this humongous fungus,” she said.
Hueber also traveled to Canada, Australia and Saudi Arabia to collect specimens. He tediously sliced them into hundreds of thin sections and made thousands of images taken through microscopes to determine the organism’s identity.
Now Boyce, Hotton and their colleagues have produced independent evidence that supports Hueber’s case. The team did so by analyzing two varieties—isotopes—of carbon contained in Prototaxites and the plants that lived in the same environment approximately 400 million years ago.
The metabolism of plants is limited by photosynthesis. Deriving their energy from the sun and their carbon from carbon dioxide in the air, any given type of plant will typically contain a similar ratio of carbon-12 to carbon-13 as another plant of the same type. “But if you’re an animal, you will look like whatever you eat,” Boyce said. And Prototaxites displayed a much wider variation in its ratio of carbon-12 to carbon-13 content than would be expected in any plant.
Geological processes can alter the isotopic composition of fossils, but Boyce and his colleagues conducted tests to verify that the carbon isotopic composition of the specimens they analyzed stemmed from organic rather than geologic factors.
As for why these bizarre organisms grew so large, “I’ve wondered whether it enabled Prototaxites to distribute its spores widely, allowing it to occupy suitable marshy habitats that may have been patchily distributed on the landscape,” Hotton said.
The relatively simple Devonian ecosystems certainly seemed to contain nothing to prevent them from growing slowly for a long time. Plant-eating animals had not yet evolved, Boyce said. But even if Prototaxites hadn’t been eaten by the dinosaurs and elephants that came much later, they probably grew too slowly to rebuild from regular disturbances of any kind, Boyce said.
“It’s hard to imagine these things surviving in the modern world,” he said.
from:
http://www-news.uchicago.edu/releases/07/070423.fungus.shtml
‘Humongous fungus’ towered over all life on land
April 23, 2007
Scientists at the University of Chicago and the National Museum of Natural History in Washington, D.C., have produced new evidence to finally resolve the mysterious identity of what they regard as one of the weirdest organisms that ever lived.
Their chemical analysis indicates that the organism was a fungus, the scientists report in the May issue of the journal of Geology, published by the Geological Society of America. Called Prototaxites (pronounced pro-toe-tax-eye-tees), the organism went extinct approximately 350 million years ago.
Prototaxites has generated controversy for more than a century. Originally classified as a conifer, scientists later argued that it was instead a lichen, various types of algae or a fungus. Whatever it was, it stood in tree-like trunks more than 20 feet tall, making it the largest-known organism on land in its day.
“No matter what argument you put forth, people say, well, that’s crazy. That doesn’t make any sense,” said C. Kevin Boyce, an Assistant Professor in Geophysical Sciences at Chicago. “A 20-foot-tall fungus doesn’t make any sense. Neither does a 20-foot-tall algae make any sense, but here’s the fossil.”
The Geology paper adds a new line of evidence indicating that the organism is a fungus. The fungus classification first emerged in 1919, with Francis Hueber of the National Museum of Natural History in Washington, D.C., reviving the idea in 2001. His detailed studies of internal structure have provided the strongest anatomical evidence that Prototaxites is not a plant, but a fungus.
“Fran Hueber has contributed more to our understanding of Prototaxites than anyone else, living or dead,” said Carol Hotton, also of the National Museum of Natural History. “He built up a convincing case based on the internal structure of the beast that it was a giant fungus, but agonized over the fact that he was never able to find a smoking gun in the form of reproductive structures that would convince the world that it was indeed a fungus,” Hotton said.
Co-authoring the Geology paper with Boyce, Hotton and Hueber himself were Marilyn Fogel, George Cody and Robert Hazen of the Carnegie Institution of Washington, and Andrew Knoll of Harvard University. Their work was funded by NASA’s Astrobiology Institute and by the American Chemical Society Petroleum Fund.
Prototaxites lived worldwide from approximately 420 million to 350 million years ago. During this period, which spans part of the Silurian and Devonian periods of geologic time, terrestrial Earth looked quite alien in comparison to the modern world.
Simple vascular plants, the ancestors of the familiar conifers, ferns and flowering plants of today, began to diversify on land during the Devonian Period. “Initially, they’re just stems. They don’t have roots. They don’t have leaves. They don’t have anything like that,” Boyce said.
Millipedes, wingless insects and worms were among the other organisms making a living on land by then, but no backboned animals had yet evolved out of the oceans. “That world was a very strange place,” Boyce said.
Although vascular plants had established themselves on land 40 million years before the appearance of Prototaxites, the tallest among them stood no more than a couple feet high. By the end of the Devonian, approximately 345 million years ago, large trees, ferns, seeds, leaves and roots had all evolved. “They’re all there. They just exploded over this one time period,” Boyce said.
Canadian paleontologist Charles Dawson published the first research on Prototaxites in 1859, based on specimens found along the shores of Gaspé Bay in Quebec, Canada. Hueber pored through Dawson’s field notebooks, written “in a completely illegible scrawl,” Hotton said.
“Fran spent months deciphering them for clues about the localities where specimens had been collected, how Dawson interpreted them and other information that helped understand this humongous fungus,” she said.
Hueber also traveled to Canada, Australia and Saudi Arabia to collect specimens. He tediously sliced them into hundreds of thin sections and made thousands of images taken through microscopes to determine the organism’s identity.
Now Boyce, Hotton and their colleagues have produced independent evidence that supports Hueber’s case. The team did so by analyzing two varieties—isotopes—of carbon contained in Prototaxites and the plants that lived in the same environment approximately 400 million years ago.
The metabolism of plants is limited by photosynthesis. Deriving their energy from the sun and their carbon from carbon dioxide in the air, any given type of plant will typically contain a similar ratio of carbon-12 to carbon-13 as another plant of the same type. “But if you’re an animal, you will look like whatever you eat,” Boyce said. And Prototaxites displayed a much wider variation in its ratio of carbon-12 to carbon-13 content than would be expected in any plant.
Geological processes can alter the isotopic composition of fossils, but Boyce and his colleagues conducted tests to verify that the carbon isotopic composition of the specimens they analyzed stemmed from organic rather than geologic factors.
As for why these bizarre organisms grew so large, “I’ve wondered whether it enabled Prototaxites to distribute its spores widely, allowing it to occupy suitable marshy habitats that may have been patchily distributed on the landscape,” Hotton said.
The relatively simple Devonian ecosystems certainly seemed to contain nothing to prevent them from growing slowly for a long time. Plant-eating animals had not yet evolved, Boyce said. But even if Prototaxites hadn’t been eaten by the dinosaurs and elephants that came much later, they probably grew too slowly to rebuild from regular disturbances of any kind, Boyce said.
“It’s hard to imagine these things surviving in the modern world,” he said.
from:
http://www-news.uchicago.edu/releases/07/070423.fungus.shtml
Circumventing the PDR pathway in fungi.
Fig. 1. Circumventing the PDR pathway in fungi. (A) In cells with clinically important resistance to azole drugs, high-level transcription of PDR efflux-pump genes involves the recruitment of RNA polymerase II, which depends on a drug-induced interaction between the ScPdr1p/Pdr3p and mediator complexes. The efflux pumps reduce the intracellular concentration of the drug below that required to inhibit the azole target Erg11p, allowing normal cell growth. (B) Binding of a multifunctional azole to the XBD domain of ScPdr1p/Pdr3p blocks expression of the drug pumps responsible for multidrug efflux and inhibits drug efflux by occupying a binding site in residual efflux pumps. The intracellular concentration of the drug is thus sufficient to block ergosterol biosynthesis in the endoplasmic reticulum. Reduced ergosterol content of membranes, production of toxic methylated sterols, and oxidative damage kill the fungal cell. Alternatively, other antifungals directly inhibit the electrogenic plasma membrane H+-ATPase Pma1p, preventing the uptake of nutrients driven by the plasma membrane electrochemical gradient. The cells die rapidly because of a limited cellular energy supply and a loss of ion balance. Partial inhibition of Pma1p activity compromises the activity of both MFS and ABC transporters and increases the potency of azole drugs. [View Larger Version of this Image (55K GIF file)]
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