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The human serotonin transporter gene (5-HTT) demonstrates two polymorphisms with possible functional impact: a 44-bp insertion/deletion polymorphism of the promoter region and a 17-bp variable number of tandem repeat polymorphism (VNTR) in intron 2 (STin2). Such genetic polymorphisms in the serotoninergic system may increase the susceptibility to schizophrenia or may serve as predictors of therapeutic response. We therefore analyzed these polymorphisms as susceptibility factors for schizophrenia by comparison of 684 schizophrenic inpatients with 587 healthy controls. We furthermore compared the therapeutic outcome of schizophrenic patients differentiated by the 5-HTT genotypes. Schizo-affective patients were more frequently homozygous for the 44-bp insertion allele (Odds ratio, OR: 1.6, 95% confidence interval, CI: 1.1-2.3, P Ͻ 0.03) than were all other schizophrenic patients and controls. The 17-bp VNTR alleles found were: STin2.7, 9, 10, and 12. Sequence analysis revealed seven different sequence motifs with an invariable arrangement. Patients with schizo-paranoid schizophrenia were more frequently homozygous for the STin2.12 allele than were controls (OR: 1.4, CI: 1.1-1.8, P Ͻ 0.007) and all other schizophrenic patients (OR: 1.6, CI: 1.2-2.3). The STin2.9 allele represented a risk factor for the residual subtype of schizophrenia (OR: 6.4, CI: 2.5-16.2, P Ͻ 0.001). On the basis of global clinical impressions, as well as measurements with the positive and negative syndrome scale we found no association of the polymorphisms with therapeutic response. In conclusion, the 44-bp polymorphism may be associated with the schizo-affective and the 17-bp VNTR with the residual and schizoparanoid subtype of schizophrenia, findings which require further biochemical and epidemiological confirmation. Molecular Psychiatry (2001) 6, 179-185.

Kava-kava, a psychoactive beverage, induces relaxation, improves social interaction, promotes sleep and plays an important role in the sociocultural life in the islands of the South Pacific. On the other hand, standardized extracts of kava-kava roots are used for the therapy of anxiety, tension and restlessness. Kava pyrones, the major constituents of kava kava, are generally considered to be responsible for the pharmacological activity in humans and animals. To obtain more information on the mechanisms by which kava-kava exerts psychotropic properties we investigated the in vitro effects of kava-kava extract and pure synthetic kava pyrones on human platelet MAO-B, in comparison to amitriptyline, imipramine and brofaromine. Kava-kava extract was found to be a reversible inhibitor of MAO-B in intact platelets (IC50 24 microM) and disrupted platelet homogenates (IC50 1.2 microM). Structural differences of kava pyrones resulted in a different potency of MAO-B inhibition. The order of potency was desmethoxyyangonin > (+/-)-methysticin > yangonin > (+/-)-dihydromethysticin > (+/-)- dihydrokavain > (+/-)-kavain. The two most potent kava pyrones, desmethoxyyangonin and (+/-)-methysticin displayed a competetive inhibition pattern with mean Ki 0.28 microM and 1.14 microM respectively. The inhibition of MAO-B by kava pyrone-enriched extracts might be an important mechanism for their psychotropic activity.

I.

We studied the midbrain SERT availability in patients with major depression and assessed the relation of SERT occupancy by citalopram to the treatment response. 21 non-medicated patients with major depression and 13 healthy controls were examined by [(123)I]-ADAM SPECT. The midbrain SERT availability (SERT V(3)'') was calculated using individual MRI scans. In 13/21 patients SPECT was repeated 7 days after oral medication with citalopram (10 mg/day). We found no significant difference in the mean midbrain SERT availability between the studied patients with major depression and healthy controls (0.86 +/- 0.27 vs. 0.71 +/- 0.44, p = 0.069). The mean SERT occupancy accounted to 61%. The degree of SERT blockade by citalopram did not correlate with the reduction in HAMD total score. Treatment with low-dosed citalopram caused individually variable occupancy of the midbrain-SERT and a rapid clinical improvement in 54% of the investigated patients.

BackgroundCactus (Opuntia ficus-indica) fiber was shown to promote weight loss in a 3-month clinical investigation. As demonstrated by in vitro studies, cactus fiber binds to dietary fat and its use results in reduced absorption, which in turn leads to reduced energy absorption and ultimately the reduction of body weight.ObjectiveThe objective of our study was to elucidate the dietary fat binding capacity of cactus fiber through determination of fecal fat excretion in healthy volunteers.Subjects and MethodsThis clinical investigation was performed as a double-blind, randomized, placebo-controlled, crossover study in healthy subjects for a period of approximately 45 days. Twenty healthy volunteer subjects were randomized to receive cactus fiber or placebo, 2 tablets thrice daily with main meals. All subjects were provided with meals during the study period (except washout) according to a standardized meal plan, with 35% of daily energy need coming from fat. Two 24-hour feces samples were collected during both the baseline and treatment periods for analysis of the fat content.ResultsCactus fiber showed an increased fecal fat excretion compared with placebo (mean [SD] = 15.79% [5.79%] vs 4.56% [3.09%]; P < 0.001). No adverse events were reported throughout the study period.ConclusionsCactus fiber has been shown to significantly promote fecal fat excretion in healthy adults. The results of our study support the hypothesis that cactus fiber helps in reducing body weight by binding to dietary fat and increasing its excretion, thus reducing dietary fat available for absorption. ClinicalTrials.gov identifier: NCT01590667.

Irritable bowel syndrome (IBS) is a functional bowel disorder of unknown aetiology. There is currently no known cure, and pharmacological interventions are usually targeting symptomatic relief, where natural and herbal remedies also play a role. This study aimed to evaluate the benefit and tolerability of IQP‐CL‐101 in symptomatic IBS relief. A double‐blinded, randomised, placebo‐controlled trial was conducted over 8 weeks. A total of 99 subjects fulfilling ROME‐III criteria for IBS were randomised into two groups, given either two IQP‐CL‐101 softgels or matching placebo twice daily before main meals. The primary endpoint was the difference in change of IBS Symptom Severity Score (IBS‐SSS) after an 8‐week intake of IQP‐CL‐101 compared to placebo. After 8 weeks, subjects on IQP‐CL‐101 showed a significant reduction in IBS‐SSS (113.0 ± 64.9‐point reduction) compared to subjects on placebo (38.7 ± 64.5‐point reduction) (p < 0.001). A significant improvement could be seen as early as 4 weeks. No serious adverse events were reported throughout. IQP‐CL‐101 can be considered beneficial in the improvement of IBS symptom severity, regardless of IBS type, and therefore able to improve quality of life in patients suffering from abdominal pain and discomfort. © 2017 The Authors. Phytotherapy Research published by John Wiley & Sons Ltd.

In view of conflicting observations made by other authors and the present findings on suicidal patients with adjustment disorder it remains doubtful whether and if so to which extent platelet studies can provide valid information on serotonergic mechanisms related to suicidal behaviour.