Novel S1P(1) receptor agonists--part 3: from thiophenes to pyridines.

In preceding communications we summarized our medicinal chemistry efforts leading to the identification of potent, selective, and orally active S1P1 agonists such as the thiophene derivative 1. As a continuation of these efforts, we replaced the thiophene in 1 by a 2-, 3-, or 4-pyridine and obtained less lipophilic, potent, and selective S1P1 agonists (e.g., 2) efficiently reducing blood lymphocyte count in the rat. Structural features influencing the compounds' receptor affinity profile and pharmacokinetics are discussed. In addition, the ability to penetrate brain tissue has been studied for several compounds. As a typical example for these pyridine based S1P1 agonists, compound 53 showed EC50 values of 0.6 and 352 nM for the S1P1 and S1P3 receptor, respectively, displayed favorable PK properties, and penetrated well into brain tissue. In the rat, compound 53 maximally reduced the blood lymphocyte count for at least 24 h after oral dosing of 3 mg/kg.

No association of CNR1 gene variations with susceptibility to schizophrenia.

Schizophrenia is one of the most common psychiatric disorders. There is a growing body of evidence associating dysregulation of the endogenous cannabinoid system with the pathogenesis of schizophrenia. In order to test the hypothesis that mutations in the central cannabinoid receptor-1 (CNR1) gene confer susceptibility to the development of schizophrenia, we performed an association study in a group of 104 German patients with schizophrenia and 140 healthy controls, using three polymorphisms within and flanking the coding exon of CNR1 (rs6454674, rs1049353, AL136096). In addition, we analyzed the whole coding region of the CNR1 gene of 50 of the patients by capillary sequencing to detect rare mutations. Our adequately powered study failed to reveal a statistically significant segregation of CNR1 polymorphisms to the diseased or control group. Furthermore, capillary sequencing of CNR1 in a subgroup of study subjects did not show any non-synonymous mutations predicting malfunction of CNR1 in patients with schizophrenia. In conclusion, we could not detect a statistically significant association between mutations in the CNR1 gene and the predisposition to develop schizophrenia. However, further studies are necessary to unravel the relationship between mutations in the CNR1 gene and the genetic susceptibility for the manifestation of certain subtypes or schizophrenia i.e. the predominance of negative or positive symptoms or as predictors of the clinical course.

Nicotine and alcohol dependence in patients with comorbid attention-deficit/hyperactivity disorder (ADHD).

AIMS: Several studies have shown that attention-deficit/hyperactivity disorder (ADHD) represents a significant risk factor for the onset and development of an addiction. Thirty-five per cent of adult ADHD patients are known to be addicted to alcohol. Many ADHD patients also have an increased nicotine consumption, which typically, leads to an improvement of attention, ability to concentrate and control of impulses. There may be pathophysiological connections here. On the other hand, it can also be assumed that there is a high prevalence of addicted patients with undiagnosed ADHD. METHODS: Ninety-one adult alcohol-dependent patients were examined for ADHD in this study, using the Wender Utah Rating Scale (WURS-k), Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) symptom check-list for ADHD and the Conners' Adult ADHD Rating Scales (CAARS, Long Version). The patients were divided into diagnostic sub-groups according to DSM-IV (inattentive type, impulsive type, combined type). Nicotine consumption was investigated using the Fagerström Test of Nicotine Dependence (FTND) and then graded as 'minimal', 'average' or 'high' nicotine dependence. RESULTS: There were 20.9% (WURS-k) or 23.1% (DSM-IV diagnostic criteria) of the patients addicted to alcohol, who showed evidence of ADHD in childhood. With the help of CAARS, it could be demonstrated that 33.3% of the patients who fulfilled the diagnostic criteria of ADHD, according to DSM-IV, had persisting ADHD in adulthood. The FTND showed a statistically significant difference in nicotine dependence between alcohol-dependent patients with and without ADHD in childhood. Patients numbering 76.2% with ADHD, demonstrated an 'average to high' level of nicotine dependence compared to 45.7% of those patients without ADHD. Furthermore, the number of patients not addicted to nicotine (19%) was significantly lower than among those without ADHD (36.6%) (P = 0.029). CONCLUSIONS: The results of this investigation reveal that a large number of ADHD patients suffer from alcohol dependence, and an even greater number from excessive nicotine dependence. The outcome indicates that there are most likely pathophysiological connections with alcohol and nicotine dependence, and that this substance abuse is probably a form of 'self-medication'. The results clearly underline the great importance of early and adequate diagnosis and therapy of ADHD, in order to prevent exacerbation of addictive illness.

[The development of alcohol dependence in Germany - results from a multicenterstudy]. / Zur Entwicklung der Alkoholabhängigkeit in Deutschland - Ergebnisse einer Multizenterstudie.

Although per capita consumption of alcohol has stagnated during the last years there is some evidence of a tendency to earlier alcohol drinking. Within the context of this study we have evaluated 556 inpatients of 25 hospitals in North Germany, specializing in alcohol problems. The results of this multicenter study draw the conclusion that the tendency of an earlier alcohol consumption is related to an earlier beginning of habit-forming drinking. Therefore young people develop a problematic drinking style at an earlier time. A fatal progress that leads to growing danger in adolescents and increasing numbers of severe alcoholics.

Effects of acute alcohol withdrawal on memory performance in alcohol-dependent patients: a pilot study.

Studies on the neuropsychological performance in detoxified alcoholic patients often begin by acknowledging that there is a cognitive impairment to be found. Only little attention has been paid to date to the question as to how acute alcohol withdrawal might affect cognitive functions. Twenty-nine alcohol-dependent inpatients, nine in moderate alcohol withdrawal, treated with carbamazepine (group 1), 10 in mild alcohol withdrawal without pharmacological treatment (group 2), 10 in mild alcohol withdrawal with carbamazepine treatment (group 3) and 31 healthy subjects as controls (group 4) underwent repeated investigations using memory tests. The tests were performed on the first, third, seventh and fourteenth days of withdrawal. Immediate free recall of a word-list was impaired in the three patient groups in comparison with the control group on the 1st day. Thereafter no significant differences could be revealed between patients and controls. In a word-list recognition test the memory functions were not impaired in group 1 and group 2 in comparison with the control subjects. However, patients in group 3 showed impairment in this recognition test in comparison with the healthy subjects on the first and third days. The present study suggests that acute alcohol withdrawal impairs memory functions, especially free recall. This should be considered in treatment interventions in the early days of withdrawal.

Stimulation of type II collagen biosynthesis and secretion in bovine chondrocytes cultured with degraded collagen.

The functional integrity of articular cartilage is dependent on the maintenance of the extracellular matrix (ECM), a process which is controlled by chondrocytes. The regulation of ECM biosynthesis is complex and a variety of substances have been found to influence chondrocyte metabolism. In the present study we have investigated the effect of degraded collagen on the formation of type II collagen by mature bovine chondrocytes in a cell culture model. The culture medium was supplemented with collagen hydrolysate (CH) and biosynthesis of type II collagen by chondrocytes was compared to control cells treated with native type I and type II collagen and a collagen-free protein hydrolysate. The quantification of type II collagen by means of an ELISA technique was confirmed by immunocytochemical detection as well as by the incorporation of (14)C-proline in the ECM after a 48 h incubation. Chondrocytes in the control group were maintained in the basal medium for 11 days. The presence of extracellular CH led to a dose-dependent increase in type II collagen secretion. However, native collagens as well as a collagen-free hydrolysate of wheat proteins failed to stimulate the production of type II collagen in chondrocytes. These results clearly indicate a stimulatory effect of degraded collagen on the type II collagen biosynthesis of chondrocytes and suggest a possible feedback mechanism for the regulation of collagen turnover in cartilage tissue.

Short-term cognitive improvement in schizophrenics treated with typical and atypical neuroleptics.

OBJECTIVE: Atypical neuroleptics seem to be more beneficial than typical ones with respect to long-term neuropsychological functioning. Thus, most studies focus on the long-term effects of neuroleptics. We were interested in whether atypical neuroleptic treatment is also superior to typical drugs over relatively short periods of time. METHODS: We studied 20 schizophrenic patients [10 males, mean age 35.5 years, mean Brief Psychiatric Rating Scale (BPRS) score at entry 58.9] admitted to our hospital with acute psychotic exacerbation. Nine of them were treated with typical and 11 with atypical neuroleptics. In addition, 14 healthy drug-free subjects (6 males, mean age 31.2 years) were enrolled in the study and compared to the patients. As neuropsychological tools, a divided attention test, the Vienna reaction time test, the Benton visual retention test, digit span and a Multiple Choice Word Fluency Test (MWT-B) were used during the first week after admission, within the third week and before discharge (approximately 3 months). RESULTS: Patients scored significantly worse than healthy controls on nearly all tests (except Vienna reaction time). Clinical ratings [BPRS and Positive and Negative Symptom Scale for Schizophrenia (PANSS)] improved markedly (p < 0.01), without a significant difference between typical and atypical medication. Clinical improvement (PANSS total score) correlated with less mistakes on the Benton test (r = 0.762, p = 0.017) and an improvement on the divided attention task (r = 0.705, p = 0.034). Neuropsychological functioning (explicit memory, p < 0.01; divided attention, p < 0.05) moderately improved for both groups under treatment but without a significant difference between atypical and typical antipsychotic drugs. CONCLUSIONS: Over short periods of time (3 months), neuropsychological disturbances in schizophrenia seem to be moderately responsive to both typical and atypical neuroleptics.