Flotillin-1 interacts with the serotonin transporter and modulates chronic corticosterone response.

Aberrant serotonergic neurotransmission in the brain is considered at the core of the pathophysiological mechanisms involved in neuropsychiatric disorders. Gene by environment interactions contribute to the development of depression and involve modulation of the availability and functional activity of the serotonin transporter (SERT). Using behavioral and in vivo electrophysiological approaches together with biochemical, molecular-biological and molecular imaging tools we establish Flotillin-1 (Flot1) as a novel protein interacting with SERT and demonstrate its involvement in the response to chronic corticosterone (CORT) treatment. We show that genetic Flot1 depletion augments chronic CORT-induced behavioral despair and describe concomitant alterations in the expression of SERT, activity of serotonergic neurons and alterations of the glucocorticoid receptor transport machinery. Hence, we propose a role for Flot1 as modulatory factor for the depressogenic consequences of chronic CORT exposure and suggest Flotillin-1-dependent regulation of SERT expression and activity of serotonergic neurotransmission at the core of the molecular mechanisms involved.

Seroprevalence and determinants of diphtheria, tetanus and poliomyelitis antibodies among adults in Berlin, Germany.

The immunity levels against diphtheria, tetanus and poliomyelitis were investigated among blood donors (n = 2079) in Berlin. Of all participants, only 60% had full, long-term protection against diphtheria, 72% against tetanus, 87% against poliomyelitis type 1, 77% against poliomyelitis type 2 and 73% against type 3. There was a striking decrease of tetanus and diphtheria immunity levels by age. Immunity levels against tetanus were higher among males, whereas females were better protected against poliomyelitis. After adjusting for confounding effects in logistic regression diphtheria immunity in those aged <40 years was significantly higher in participants from East-Berlin, whereas the immunity levels against poliomyelitis were higher in West-Berlin. These differences reflect the different vaccination policies in East-Germany and West-Germany before 1989. There is a need to improve the immunity levels of the adult population in Berlin.

[High percentage of isolated anti-HBc-positive persons among prisoners]. / Hoher Prozentsatz isoliert anti-HBc-positiver Personen unter Strafgefangenen.

PURPOSE: Is the result "isolated Anti-HBc" higher among prisoners than in the normal population and can testing for HBV-DNA clarify the results? PATIENTS AND METHODS: In Berlin, 519 prisoners were serologically tested in 1994 for hepatitis-B and -C because of intravenous drug abuse and alcohol disease or signs of hepatitis. Beside virus antigen and antibodies, HBV-DNA was also measured by hybridisation technique or PCR. RESULTS: 50.3% of all individuals showed markers of hepatitis-B and 36.8% of hepatitis-C. 19.2% of persons with hepatitis B markers were positive for anti HBc only, i.e. more than twice as many than in the normal population. 90% of the isolated anti-HBc-positive Persons were also anti-HCV positive, which is nearly double the number of individuals with other patterns of HBV markers. Half of them were tested for HBV-DNA. Whereas the hybridisation technique failed to detect HBV-DNA, 36% of sera were found positive by HBV-PCR. CONCLUSION: This study shows again that the result "anti-HBc alone" is relatively frequent especially among prisoners. This pattern often seems associated with concurrent HCV-infection and in one third of the cases correlated with a chronic hepatitis-B. The result of an isolated anti-HBc should therefore always lead to further testing of anti-HCV and HBV-DNA by PCR.

[Retrospective evaluation of western blot for detection of early HIV infections]. / Retrospektive Bewertung des Western Blot zur Erfassung früher HIV-Infektionen.

The purpose of HIV diagnosis is to establish safely whether there is an infection or not. The enzyme-linked immunosorbent assay (ELISA) as screening test, and the western blot assay for confirmation is the most widely used serologic test system to get this information. Diagnostic problems occur if the two tests yield different results. In our 1993 study 491 (4.4%) of 11,127 tested sera were reactive by ELISA. 39 (7.9%) of these samples could not be confirmed by western blot, giving negative or indeterminate results. In addition, 370 ELISA-negative samples were tested by HIV-1 western blot to detect the infection in the early stage. 115 (31%) of these sera showed indeterminate western blot patterns, the other samples were negative. Results of follow-up investigations of 26 (Table 1) or 11 (Table 2) persons with indefinite serodiagnosis were analysed. HIV infection was not detected in any of these cases. In the literature, persons whose sera were reactive according to ELISA and were indeterminate in western blot, had a 3-5% probability of an aisting HIV infection. In contrast, indeterminate western blot patterns in ELISA-negative sere were without significance for the prognosis as to whether a person was or was not HIV-infected.

Effects of an acute saline infusion on fluid and electrolyte metabolism in humans.

Several hormonal systems participating in body fluid and electrolyte homeostasis were investigated in six healthy volunteers in a supine body position during a period of 9 days and nights. Under strictly controlled conditions, striking circadian rhythms were observed for plasma levels of vasopressin, renin, aldosterone, guanosine 3',5'-cyclic monophosphate, cortisol, and epinephrine. Nocturnal decreases and diurnal increases in urine flow rate and urinary excretion of electrolytes were observed and closely paralleled the urinary excretion of urodilatin. During 48 h after an acute isotonic saline infusion (2 liters within 25 min) and after a 48-h control experiment the urinary excretion of H2O and electrolytes, and simultaneously the alterations in endocrine systems participating in body fluid homeostasis, were determined. Urine flow and urinary electrolyte excretion rates were significantly increased during 2 days after the saline infusion. The largest increase in urinary fluid and electrolyte excretion was observed between 3 and 22 h postinfusion. These long-term changes were paralleled by altered H2O and Na balances and also by elevated body weights that returned to baseline values with an approximate half-life of 7 h. These data suggest that vasopressin, atrial natriuretic peptide, and catecholamines are unlikely to be of major importance for the renal response to this hypervolemic stimulus. The renin-aldosterone system was suppressed during 2 days postinfusion. This suppression correlated with the effects of saline load on Na excretion. However, the closest relation with Na excretion was observed for the kidney-derived member of the atrial natriuretic peptide family, urodilatin, which was considerably increased during the long-term period up to 22 h postinfusion. Thus these data show that the human body in supine position requires approximately 2 days to regulate the amount of Na and H2O provided by an acute saline infusion. The data also suggest that urodilatin and the renin-aldosterone system might participate in the long-term renal response to an acute saline infusion and also in the mediation of circadian urinary excretion rhythms.