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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although the majority of cannabinoid users smoke marijuana, the preponderance of laboratory animal research is based on administration of Delta9-tetrahydrocannabinol (Delta9-THC) or other cannabinoid agents via injection. The aim of the present study was to evaluate the impact of inhaling marijuana, or ethanol-extracted placebo smoke in the mouse model of cannabinoid activity by assessing inhibition of spontaneous activity, antinociception, catalepsy, and body temperature. In order to determine dosimetry, blood levels of Delta9-THC were obtained following either marijuana exposure or intravenous injection of Delta(9)-THC. Inhalation exposure to marijuana produced dose-related increases in antinociception and catalepsy, with estimated ED50 doses of Delta9-THC of 2.4 and 3.8 mg/kg, respectively. However, hypothermia and locomotor depression occurred in both the placebo- and marijuana-exposed mice. The CB1 receptor antagonist, SR 141716A antagonized the antinociceptive effects of marijuana (AD50 = 0.6 mg/kg), but only slightly decreased marijuana-induced catalepsy, and failed to alter either the hypothermic or locomotor depressive effects. In contrast, SR 141716A antagonized the antinociceptive, cataleptic, and hypothermic effects of intravenously administered Delta9-THC in mice that were exposed to air alone, though all subjects exhibited locomotor depression, possibly related to the restraint. In accordance with reports of others, these data suggest that exposure to smoke alone has pharmacological consequences. Our findings also indicate that marijuana-induced antinociception is mediated through a CB1-receptor mechanism of action and are consistent with the notion that Delta9-THC is mainly responsible for this effect.
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PMID:The pharmacological activity of inhalation exposure to marijuana smoke in mice. 1137 14

Addition of nitrite-N at 1.5 mg l(-1) in tryptic soy broth (TSB) significantly (p < 0.05) decreased the growth rate of the bacterial pathogen Lactococcus garvieae and significantly (p < 0.05) reduced mortality compared to zero nitrite controls when injected into giant freshwater prawns Macrobrachium rosenbergii at 5 x 10(5) colony-forming units (CFU) per prawn. In other experiments, whereby prawns were injected with TSB-grown L. garvieae (5 x 10(5) CFU prawn(-1)) and then held in water containing nitrite-N, mortality at 72 h post-injection was significantly (p < 0.05) higher for prawns held in water containing 1.68 mg l(-1) nitrite than at lower concentrations. Prawns exposed to different concentrations of nitrite-N were examined for THC (total hemocyte count), phenoloxidase activity, respiratory burst, phagocytic activity and bacterial clearance efficiency. No significant differences in THC and phenoloxidase activity were observed among treatments. With prawns exposed to nitrite-N for 168 h (7 d) at 1.59 mg l(-1), phagocytic activity and clearance efficiency decreased, while at 1.15 mg l(-1) or more, respiratory burst increased, generating the superoxide anion at levels considered cytoxic to the host. We conclude that nitrite-N at 1.68 mg l(-1) causes depression in the immune response and increased mortality in M. rosenbergii infected with L. garvieae.
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PMID:Effect of nitrite on interaction between the giant freshwater prawn Macrobrachium rosenbergii and its pathogen Lactococcus garvieae. 1221 75

Longterm use of marijuana has been found to cause physiological changes that can alter individual reproductive potential. The effects of marijuana depend on the dose and can include death from depression of the respiratory system. Longterm effects are however particularly hard to assess. Marijuana is absorbed rapidly and eliminated very slowly. The active principle, delta-9-tetrahidrocannabinol (delta-9-THC), is highly liposoluble and fixes to the serum proteins, passing to the lungs and liver for metabolization and to the kidneys and liver for excretion. As with estrogens, there is an enterohepatic circuit for reabsorption and elimination. 90% is eliminated in the feces, 65% within 48 hours. Because of the enterohepatic circuit and liposolubility, elimination requires 1 week for completion. The other important biotransformation of the active principle is hydroxilation; the hydroxilated derivatives are responsible for the psychoactivity of cannabis. Cannabis affects both neuroendocrine function and the germ cells. Studies on experimental animals have indicated that THC can cause a decline in the pituitary hormones follicle stimulating hormone, luteinizing hormone, and prolactin, and in the steroids progesterone, estrogen, and androgens. Human studies have shown that chronic users have decreased levels of serum testosterone. Because steroidogenesis can be restimulated with human chorionic gonadotropin, it appears that THC does not directly affect steroid production by the corpus luteum, but that its action is mediated by the hypothalamus. Because of its potent antigonadotropic action, THC is under study as an anovulatory agent. The same animal studies have shown that ovulation returns to normal 6 months after termination of use. High rates of anovulation and luteal insufficiency have been observed in women smoking marijuana at least 3 times weekly. THC accumulates in the milk. Animal studies have shown that THC depresses the enzymes necessary for lactation and causes a diminution in the volume of the mammary glands. In recent studies, significant amounts of the drug have been detected in both mothers' milk and the blood of newborns. Animal studies indicate that THC crosses the placenta, achieving concentrations in the fetus as high as those in the mother. Animal studies also demonstrated increasing frequency of abortions, intrauterine death, and declines in fetal weight. The effects were probably due to an alteration in placental function. A human study likewise showed that marijuana use during pregnancy was significantly related to poor fetal development, low birth weight, diminished size, and decreased cephalic circumference. Congenital malformations have been observed in experimental animals exposed to THC. Declines in sperm volume and count and abnormal sperm motility have been observed in chronic marijuana users. In vitro studies show that THC produces a marked degeneration of human sperm.
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PMID:[Review and update: marijuana and reproduction]. 1228 Dec 77

This article presents data from two avenues of marijuana research. First, the author shows that daily marijuana smoking in healthy individuals produces dependence, as demonstrated by withdrawal symptoms such as increased irritability and depression and decreased food intake. In addition, two antidepressant medications were evaluated to assess their potential effectiveness in the treatment of marijuana withdrawal symptoms: (1) sustained-release bupropion (0, 300 mg/day) and (2) nefazodone (0, 450 mg/day). Research participants were regular marijuana smokers who lived in a residential laboratory in groups of two to four. While inpatients, participants smoked active marijuana (2.8%-3.1% THC) repeatedly for 4 days, followed by 8 to 12 days of placebo marijuana (0.0% THC). Results show that during marijuana abstinence, (1) bupropion increased ratings of irritability, depression, and stomach pain and decreased food intake and sleep quality compared to placebo maintenance, and (2) nefazodone decreased anxiety during marijuana withdrawal but did not alter ratings of irritability and misery. Thus, neither medication showed promise as potential treatments for symptoms of marijuana withdrawal. The second avenue of research focused on the effect of cannabinoids in individuals with muscle mass loss, an indicator of wasting in HIV illness. Given that there are little scientific data contributing to the debates concerning medical marijuana, this study directly compared the effects of oral delta9-THC (0, 10, 20, 30 mg PO) to smoked marijuana (0.0%, 1.8%, 2.8%, 3.9% THC) in HIV + marijuana smokers with muscle mass loss (< 90% body cell mass/height). Multiple dimensions of human behavior were measured, including food intake, mood, and cognitive performance. Drugs were administered using a within-subject, double-blind, staggered, double-dummy design. Participants were free to self-select from a variety of foods throughout most of the session. Preliminary data (n = 9) suggest that oral THC was more effective at increasing food intake, but the volunteers "liked" the effects of smoked marijuana more than the effects of oral THC.
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PMID:Effects of smoked marijuana in healthy and HIV + marijuana smokers. 1241 34

Giant freshwater prawns Macrobrachium rosenbergii (14-19 g) were challenged with Enterococcus (3 x 10(5) cfu prawn(-1)) previously incubated in TSB medium for 24 h, then placed in water having concentrations of dissolved oxygen (DO) at 7.75, 4.75, 2.75 and 1.75 mg l(-1). Onset of mortality occurred after 6 h exposure to 1.75 mg l(-1) DO, and after 12 h exposure to 2.75 mg 1(-1) DO. Cumulative mortality of prawns at 1.75 mg l(-1) DO was significantly higher than that at 4.75 and 2.75 mg l(-1) DO, and cumulative mortality of prawns at 4.75 and 2.75 mg l(-1) DO was significantly higher than that at 7.75 mg l(-1) DO after 96 h. The prawns (20-30 g) which had been placed in water for 0 to 120 h at 7.75, 4.75, 2.75 and 1.75 mg l(-1) DO were examined for the THC (total haemocyte counts), DHC (differential haemocyte counts), phenoloxidase activity, respiratory burst, percentage phagocytosis and clearance efficiency. No significant difference in semi-granular cells and granular cells of prawns was observed among four treatments. The prawns following 120 h exposure to 2.75 mg l(-1) DO decreased significantly the hyaline cells and THC by 39% and 36%, respectively. Phenoloxidase activity and respiratory burst decreased significantly by 33% and 11% when the prawns were exposed to 2.75 mg l(-1) DO after 24 h, respectively. Percentage phagocytosis and clearance efficiency to Enterococcus decreased significantly by 44% and 54% for the prawns following 12 h exposure to 2.75 mg l(-1) DO, respectively. It is concluded that DO as low as 2.75 mg l(-1) and 4.75 mg l(-1) causes depression in immune system of M. rosenbergii, and increases its susceptibility to Enterococcus infection.
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PMID:Effect of hypoxia on the immune response of giant freshwater prawn Macrobrachium rosenbergii and its susceptibility to pathogen Enterococcus. 1245 42

Cannabinoids, the active components of marijuana, affect memory and hippocampal neurotransmission. It has been claimed that nabilone, a synthetic cannabinoid endowed with antiemetic properties, has a peculiar profile of actions. We studied the effects of the drug on spatial learning and in vitro hippocampal CA1 electrophysiology in the rat. Nabilone (0.1, 0.5, and 1.0 mg/kg ip) does not impair place learning in a water maze task, whereas Delta(8)-tetrahydrocannabinol (Delta(8)-THC) disrupts this function. At concentrations ranging from 1 nM to 10 microM nabilone does not influence basal glutamatergic neurotransmission, which is decreased by Delta(8)-THC. Although cannabinoids have been consistently reported to affect synaptic plasticity, nabilone 1 microM does not change paired-pulse facilitation, long-term potentiation and the magnitude of long-term depression. However, the time course of the latter phenomenon is significantly changed by the drug, the depression being lower than in control experiments from 7 to 35 min postinduction. Altogether, our data indicate that there might be differences in the effects of agonists for central cannabinoid receptors, which could help to understand the pharmacology of this class of molecules. The results also suggest that amnesia induced by cannabinoids be possibly related to their effects on hippocampal neurotransmission. The study supports the use of nabilone in conditions the course of which is complicated by cognitive impairment.
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PMID:Effects of the synthetic cannabinoid nabilone on spatial learning and hippocampal neurotransmission. 1289 76

Growth of Vibrio alginolyticus was not affected by TSB medium containing ammonia-N concentration in the range of 0-20 mg l(-1). White shrimp Litopenaeus vannamei (7-12 g in the intermolt stage) were challenged with V. alginolyticus, which had been incubated for 24 h in the TSB medium containing different concentrations of ammonia-N (0, 1, 5. 10 and 20 mg l(-1)). There was no significant difference in cumulative mortality for shrimp incubated in the TSB medium containing 0, 1, 5, 10 and 20 mg l(-1)ammonia-N after 120 h of challenge. The shrimps were challenged with V. alginolyticus previously incubated in the TSB medium for 24 h, then placed in water containing concentrations of ammonia-N at 0.01 mg l(-1)(control), 1.10, 5.24, 11.10 and 21.60 mg l(-1). Mortality of shrimp in 5.24, 11.10 and 21.60 mg l(-1)was significantly higher than those in the control solution (0.01 mg l(-1)) after 48-168 h. Shrimps which had been exposed to control, 1.10, 5.24, 11.10 and 21.60 mg l(-1)ammonia-N for 7 days were examined for THC (total haemocyte count), granular cells, hyaline cells, phenoloxidase activity, release of superoxide anion, superoxide dismutase (SOD) activity, phagocytic activity and clearance efficiency to V. alginolyticus. No significant difference in THC, hyaline cells and granular cells were observed among shrimps at different ammonia-N concentrations. Phenoloxidase activity however, decreased when the shrimps were exposed to 5.24 mg l(-1)ammonia-N and greater after 7 days. The release of superoxide anion increased significantly, whereas SOD activity decreased significantly at 21.60 mg l(-1)ammonia-N. With shrimps exposed to 11.21 and 21.22 mg l(-1)ammonia-N for 7 days, phagocytic activity and clearance efficiency to V. alginolyticus significantly decreased. It is therefore suggested that ammonia in water caused a depression in the immune response and an increase in mortality of L. vannamei from the V. alginolyticus infection.
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PMID:Effect of ammonia on the immune response of white shrimp Litopenaeus vannamei and its susceptibility to Vibrio alginolyticus. 1512 1

Taiwan abalone Haliotis diversicolor supertexta held in 30 parts/per thousand seawater and 26 degrees C were injected with TSB-grown Vibrio parahaemolyticus (1.6 x 10(5)cfu abalone(-1)), and then placed in water containing different concentrations of ammonia-N (un-ionized plus ionized ammonia) at 0.01 mg l(-1) (control), 1.12, 3.22, 5.24 and 10.18 mg l(-1). Mortality of abalone increased directly with ambient ammonia-N concentration. After 12 h, the mortality of V. parahaemolyticus-injected abalone held in 3.22 mg l(-1) ammonia-N was significantly higher than those placed in 1.12 mg l(-1) ammonia-N and the control solution. In another experiment, the abalone which had been exposed to control, 1.08, 3.16, 5.37 and 10.34 mg l(-1) ammonia-N for 24, 72 and 120 h were examined for THC (total haemocyte count), phenoloxidase activity, respiratory burst (release of superoxide anion), and phagocytic activity and clearance efficiency to V. parahaemolyticus. The abalone when exposed to 3.16 mg l(-1) ammonia-N had decreased THC after 72 h, and decreased phenoloxidase activity, phagocytic activity and clearance efficiency after 24 h. However, the abalone when exposed to 3.16 mg l(-1) ammonia-N had increased respiratory burst after 24 h. The immune parameters except superoxide anion seemed to be suppressed in a dose-dependent fashion after 24 h. It is concluded that ammonia caused a depression in immune parameters and an increase in mortality of H. diversicolor supertexta from V. parahaemolyticus infection.
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PMID:Effect of ammonia on the immune response of Taiwan abalone Haliotis diversicolor supertexta and its susceptibility to Vibrio parahaemolyticus. 1527 99

The white shrimp Litopenaeus vannamei were challenged with tryptic soy broth (TSB)-grown Vibrio alginolyticus at a dose of 1 x 10(6) colony-forming units (cfu) shrimp(-1), and then placed in water containing concentrations of nitrite-N at 0 (control), 1.12, 5.15, 11.06 and 21.40 mg l(-1). Mortality of shrimp in 5.15, 11.06 and 21.40 mg l(-1) was significantly higher than those in the control solution after 48-168 h. L. vannamei that had been exposed to control, 0.98, 4.94, 9.87 and 19.99 mg l(-1) nitrite-N for 96 h were examined for THC (total haemocyte count), phenoloxidase activity, and respiratory burst (release of superoxide anion). The THC and phenoloxidase activity decreased when the shrimp were exposed to 4.94, 9.87 and 19.99 mg l(-1) nitrite-N, whereas, the respiratory burst increased significantly at 9.87 and 19.99 mg l(-1) nitrite-N after 96 h. It is therefore suggested that nitrite in water caused a depression in the immune ability of L. vannamei and an increased susceptibility to V. alginolyticus infection, together with an increase of superoxide anion production, possibly to cytotoxic levels for the host.
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PMID:The immune response of white shrimp Litopenaeus vannamei and its susceptibility to Vibrio alginolyticus under nitrite stress. 1531 59

White shrimp Litopenaeus vannamei (Boone) held in 35 per thousand seawater were challenged with Vibrio alginolyticus at a dose of 3 x 10(5) colony-forming units (cfu) shrimp(-1), and then placed in water containing concentrations of Cu2+ at 0 (control), 1, 5, 10 and 20 mg l(-1). Mortality of shrimp in 5, 10 and 20 mg l(-1) Cu2+ was significantly higher than those in 1 mg l(-1) Cu2+ and the control solution after 24-96 h. In another experiment, L. vannamei which had been exposed to control, 1, 5, 10 and 20 mg l(-1) Cu2+ for 24, 48 and 96 h were examined for THC (total haemocyte count), phenoloxidase activity, respiratory burst (release of superoxide anion), phagocytic activity and clearance efficiency to V. alginolyticus. Copper concentrations at 1 mg l(-1) or greater for 24h resulted in decreased THC, phenoloxidase activity, phagocytic activity and clearance efficiency, whereas copper concentration at 20 mg l(-1) caused significant increase in respiratory burst of L. vannamei. In conclusion, concentration of Cu2+ at 1 mg l(-1) or greater increased the susceptibility of L. vannamei to V. alginolyticus infection by a depression in immune ability. The release of superoxide anion by L. vannamei exposed to 20 mg l(-1) Cu2+ was considered to be cytotoxic to the host.
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PMID:Effect of copper sulfate on the immune response and susceptibility to Vibrio alginolyticus in the white shrimp Litopenaeus vannamei. 1531 10


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