Concentration and depression

Experiment 2. Effects of terpenoid allelochemicals on pollen germination The effects of the terpenoids found in many allelopathically active plants are dependent on the concentration of the active matter (Fig. 4). Linalool, cymol, citral, gaillardine and austricine excreted by many flowers, stimulated the pollen germination upto 10 7-1()" M concentrations and depress in higher ones. Rodriguez et.al (1976) described the biological effects of some sesquiterpene lactones, which are allelochemicals. 

Tiagabine is indicated for the adjunctive treatment of partial seizures and is effective in doses ranging from 16 mg/d to 56 mg/d. Divided doses as often as four times per day are sometimes required. Some patients appear to do well with tiagabine monotherapy, which is generally well tolerated. Minor adverse events are dose-related and include nervousness, dizziness, tremor, difficulty in concentrating, and depression. Excessive confusion, somnolence, or ataxia may require discontinuation. Psychosis occurs rarely. Rash is an uncommon idiosyncratic adverse effect. Laboratory studies are usually normal. 

Capuron L, Ravaud A, Neveu PJ, Miller AH, Maes M, Dantzer R (2002) Association between decreased serum tryptophan concentrations and depressive symptoms in cancer patients undergoing cytokine therapy. Mol Psychiatry 7 468-473. 

The multiple chemical sensitivity (MCS) syndrome is a term that has been used to describe a constellation of non-specific systemic symptoms occurring after exposure to a wide variety of irritating agents. Patients present with headaches, food intolerance, fatigue, lack of concentration and depression which they attribute to their work environments. These symptoms subside... 

Finally, changes in extracellular calcium (in the low millimolar range) can modulate nicotinic responses. Increases in calcium concentration strongly enhance macroscopic responses of either native or recombinant heteromeric nicotinic receptors to low ACh concentrations, decreasing the BC value of ACh and increasing the Hill slope of the curve (133, 140, 160, 161). This effect is not seen with muscle embryonic channels (133). In native a7 receptors the modulation has been reported to be biphasic, with potentiation at submillimolar calcium concentrations and depression at higher concentrations (162). The sequence determinants for this effect have... 

Compressed gas systems were originally developed simply to provide a means of expelling a product from its container when the valve was depressed. SemisoHd products such as a cream, ointment, or caulking compound are dispensed as such. A Hquid concentrate and a compressed gas propellant (Fig. 3) produce a spray when a mechanical breakup actuator is used. Nitrogen, insoluble in most materials, is generally used as the propellant. 

Toxicity. 1,1-Dichloroethane, like all volatile chlorinated solvents, has an anesthetic effect and depresses the central nervous system at high vapor concentrations. The 1991 American Conference of Governmental Industrial Hygienists (ACGIH) recommends a time-weighted average (TWA) solvent vapor concentration of 200 ppm and a permissible short term exposure level (STEL) of 250 ppm for worker exposure. The oral LD q of... 

Antagonists can produce varying combinations of dextral displacement and depression of maxima of agonist dose-response curves. The concentration-related effect of an antagonist on the system response to a single concentration of agonist constitutes what will be referred to as an inhibition curve. One of the most straightforward examples... 

It was found that the law of proportionality (12) holds good only if the solution is dilute, and in the determination of

different concentrations in dilute solutions, plotting these against the concentrations, and extrapolating to zero concentration, or infinite dilution (H.M., 67). 

Depression occurring as part of bipolar disorder may be severe and accompanied by ideas of guilt and hopelessness, an inability to function at work because of poor concentration and psychomotor retardation or agitation, poor judgement and suicidal ideation. The lifelong risk of suicide in people with this condition is as high as 15%. Factors associated with suicide risk include alcohol misuse, marital separation or divorce, living alone and unemployment, and these are all common secondary consequences of the illness. 

O Classic views as to the cause of major depressive disorder focus on the monoamine neurotransmitters norepinephrine (NE), serotonin (5-HT), and to a lesser extent, dopamine (DA) in terms of both synaptic concentrations and receptor functioning. 

The tricyclic antidepressants (TCAs), such as imipramine, can alleviate symptoms of ADHD. Like bupropion, TCAs likely will improve symptoms associated with comorbid anxiety and depression. The mechanism of action of TCAs is in blocking norepinephrine transporters, thus increasing norepinephrine concentrations in the synapse the increase in norepinephrine is believed to alleviate the symptoms of ADHD. TCAs have been demonstrated to be an effective non-stimulant option for ADHD but less effective than stimulants. However, their use in ADHD has declined owing to case reports of sudden death and anticholinergic side effects6,13 (Table 39-3). Further, TCAs may lower seizure threshold and increase the risk of car-diotoxicity, (e.g., arrythmias). Patients starting on TCAs should have a baseline and routine electrocardiograms. 

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