Immunological mechanisms giving rise to latency of herpes simplex virus in the spinal ganglia of the mouse

In the model of genital herpes simplex virus (HSV)-infection of mice, early latency could be induced by passive immunization with HSV-specific antibodies and, to a lesser degree, by adoptive transfer of immune lymphocytes prepared from spleen and draining lymph nodes of genitally infected syngeneic mice. Conversely, spontaneously occurring latency was inhibited by treatment of the animals with cyclophosphamide (Cph) and, to a lesser degree, with cyclosporin A (CyA). Whereas the effect of CyA could be compensated by passively administered HSV-specific antibodies, that of Cph could not. Apparently specific antibodies cooperate with a non-specific proliferating cell type, probably macrophages and/or NK-cells, as could be demonstrated by significantly reduced antibody effect in silica-treated mice. Moreover, F(ab)₂ fragments, in contrast to complete antibody molecules, were inactive. HSV-specific antibodies and also immune lymphocytes had little effect on virus production in the mucous membranes, immune lymphocytes being at least as active as antibodies. It is therefore not probable that latency is induced by attenuation of the peripheral disease. It can rather be concluded that the neuron itself is the target for the action of specific antibodies, cooperating in turn with macrophages and/or NK cells.With support of the Deutsche Forschungsgemeinschaft, Schn 174/6-3     

Lipid-drug conjugate nanoparticles of the hydrophilic drug diminazene-cytotoxicity testing and mouse serum adsorption.

Sleeping sickness is a widely distributed disease in great parts of Africa. It is caused by Trypanosoma brucei gambiense and rhodiense, transmitted by the Tse-Tse fly. After a hemolymphatic stage, the parasites enter the central nervous system where they cannot be reached by hydrophilic drugs. To potentially deliver the hydrophilic antitrypanosomal drug diminazene diaceturate to the brain of infected mice, the drug was formulated as lipid-drug conjugate (LDC) nanoparticles (NP) by combination with stearic- (SA) and oleic acid (OA). To estimate the in vivo compatibility, the particles were incubated with human granulocytes. Because as potential delivery mechanism the absorption of specific serum proteins (ApoE, Apo AI and Apo AIV) was found to be responsible for the delivery of nanoparticles to the brain, demonstrated using PBCA nanoparticles coated with polysorbate 80 (LDL uptake mechanism) the nanoparticles were incubated with mouse serum and the adsorption pattern was determined using the 2-D PAGE technique. As a result of this study, the cytotoxic potential was shown to decrease when diminazene is part of the particle matrix compared to pure fatty acid nanoparticles and the mouse serum protein adsorption pattern differs from the samples studied earlier in human serum. Especially, the fact concerning Apo-E that could be detected when the particles were incubated in human serum is absent after the mouse serum incubation, potentially, is a critical point for the delivery via the LDL-uptake mechanism but the data demonstrate that LDC nanoparticles, with 33% (wt/wt) drug loading capacity possess the potential to act as a delivery system for hydrophilic drugs like diminazene diaceturate and that further studies have to demonstrate the usability as a brain delivery system.     

Alcohol-induced heart rate response dampening during aversive and rewarding stress paradigms in subjects at risk for alcoholism.

Individuals with a family history of alcoholism (FH+) are at risk to develop alcohol problems. In several studies, psychophysiological stress responses were more attenuated by alcohol in FH+ than in FH- subjects. However, it is not clear from these studies, if this stronger stress-response dampening effect of alcohol (SRD) in FH+ subjects is confined to aversive stimuli, or would hold for nonaversive stress conditions as well. Also, male and female FH+ subjects seem to respond differently to the alcohol challenge, but have rarely been directly compared in a SRD paradigm. Participants were 54 female and 63 male healthy adults; 31 women were daughters (DOAs) and 40 men were sons (SOAs) of alcohol-dependent fathers. The remaining 23 women (DONAs) and 23 men (SONAs) had no FH of any alcohol use disorder. The participants took part in two laboratory sessions, one with and one without alcohol. In each session, three stressor procedures were presented. Heart rate is the main dependent variable in this report. SOAs, but not SONAs showed a tendency towards SRD. Among female participants, a strong SRD occurred, but contrary to our expectation only in controls. Stress responses and SRD effects were somewhat stronger in the aversive than in the rewarding task. The extent of alcohol induced SRD was strongly influenced by BAL and the amplitude of the stress response in the no-alcohol condition (multiple regression analysis). Thus, aversive tasks might have the advantage of eliciting stronger stress responses than rewarding tasks, thereby providing better conditions for observing differences in alcohol induced SRD between FH+ and FH- subjects.     

Temperature-influenced ordering of mesogens in comb-like liquid-crystalline poly(methylsiloxane) macromolecules with side groups consisting of “phenyl benzoate” moieties in solution

Comb-like poly(methylsiloxane) macromolecules P4, P6, and P11, with side groups consisting of “phenyl benzoate” moieties and different alkyl spacers (from 4 to 11 C-atoms) between the backbone and the mesogenic side groups have been synthesized and investigated as well as low-molar-mass compounds M4, M6, and M11, as model molecules analogous to side chains of the macromolecule. The liquid-crystalline phase transition temperatures have been determined. Mobility of the mesogens and the macromolecule as a whole in dilute solution was studied in external fields (electric and mechanical shear field). In dilute solution under the influence of a sinusoidal electric field, the polymer behaviour is typical of flexible-chain polymer molecules where each mesogenic unit is oriented independently of the other ones. This is in contrast to the effect observed in a mechanical shear flow field. The Maxwell constant in positive for the solutions of compounds M4, M6, M11 and negative in polymers P4, P6, P11. This indicates the orientation of the macromolecule as a whole in the shear flow field, the mesogenic group main axis being oriented in the direction preferably normal to the macromolecular axis of primary polarizability. Temperature effects are also discussed.     

Dysfunction of axonemal dynein heavy chain Mdnah5 inhibits ependymal flow and reveals a novel mechanism for hydrocephalus formation

Motility of unicellular organisms occurred early in evolution with the emergence of cilia and flagella. In vertebrates, motile cilia are required for numerous functions such as clearance of the airways and determination of left-right body asymmetry. Ependymal cells lining the brain ventricles also carry motile cilia, but their biological function has remained obscure. Here, we show that ependymal cilia generate a laminar flow of cerebrospinal fluid through the cerebral aqueduct, which we term as 'ependymal flow'. The axonemal dynein heavy chain gene Mdnah5 is specifically expressed in ependymal cells, and is essential for ultrastructural and functional integrity of ependymal cilia. In Mdnah5-mutant mice, lack of ependymal flow causes closure of the aqueduct and subsequent formation of triventricular hydrocephalus during early postnatal brain development. The higher incidence of aqueduct stenosis and hydrocephalus formation in patients with ciliary defects proves the relevance of this novel mechanism in humans.     

Long- and short-term effects of biological hydrogels on capsule microvascular density around implants in rats

Fibrous capsule formation around implants can inhibit solute exchange between implantable devices and the circulation. Parylene-n coated polycarbonate disks surrounded with growth factor reduced Matrigel (MG) or several gelatin-based matrices were implanted intramuscularly into rats for 21 or 50 days. MG supplemented with vascular endothelial growth factor (VEGF) or basic fibroblast growth factor (bFGF) increased capsule microvascular density at 21 days (p < 0.05) when compared to bare parylene-coated polycarbonate disks (control). The increased microvascular density around VEGF- and bFGF-treated implants regressed by 50 days and was no longer significantly different from controls. The microvascular density induced by the gelatin-based matrices was not significantly different from controls at 21 days, but was increased at 50 days (p < 0.05), suggesting a slower, long-term effect. Disks treated with MG and gelatin-based matrices had thinner capsules at 21 days (p < 0.05). By 50 days, the capsule thicknesses around these implants were no longer statistically thinner than controls. The capsule thickness around implants treated with VEGF, bFGF, and essential gelatin-based matrix was thinner than controls at 50 days (p < 0.05). These results indicate that it is possible to increase functional microvascular density within fibrous capsules using angiogenic growth factors and gelatin-based matrices. However, this effect may be short-lived, requiring chronic administration of growth factors.     

Gefühl ohne Sprache oder Sprache ohne Gefühl? Weitere Hinweise auf die Validität der Entkopplungshypothese der Alexithymie

The theoretical background of the present investigation was the decoupling hypothesis of alexithymia, which presumes for alexithymic individuals a dissociation of psychophysiological indicators of emotion from verbal cognitive awareness of one's emotional state. To study alterations in reactivity to emotionally distressing stimuli in alexithymic individuals, 12 high-alexithymic and 14 low-alexithymic subjects (separated by TAS) out of a general sample of 54 were investigated. All subjects were exposed to cognitive (CPT) and affect inductive (film sequences) distress. During stimulus exposition electrodermal activity (spontaneous fluctuations) was recorded. After stimulus exposition the subjects assessed their emotional reaction towards the film sequences (DAS). Concerning electrodermal activity no differences were found between high and low alexithymics under cognitive distress. In any case a significant autonomous arousal was registered. However, only the low alexithymic subjects but not the high alexithymics showed a significant increase of spontaneous fluctuations as expression of autonomous arousal during presentation of affect inductive stimuli. The altered psychophysiological reactivity found in high alexithymics in contrast to low alexithymic subjects was revealed specifically for the processing of emotional qualified stimuli. However, there was no difference between the groups in cognitive self assessment of emotional response towards the film sequences. The findings are discussed with reference to neurophysiological and psychodynamic models and the decoupling hypothesis of alexithymia.     

Lipoprotein(a) stimulates growth of human mesangial cells and induces activation of phospholipase C via pertussis toxin-sensitive G proteins

BACKGROUND: Renal disease is commonly associated with hyperlipidemia and correlates with glomerular accumulation of atherogenic lipoproteins, for example, lipoprotein(a) [Lp(a)], and mesangial hypercellularity. Specific binding of Lp(a) to mesangial cells and induction of c-myc and c-fos expression has been demonstrated. Therefore, in this study, we investigated a possible growth stimulatory effect and mode of action of Lp(a) in human mesangial cells. METHODS: Lp(a) was purified from the regenerate fluid of a dextran sulfate column-based low-density lipoprotein apheresis system. Human mesangial cells were isolated by a sequential sieving technique from patients undergoing tumor nephrectomy. DNA synthesis was measured by [3H]-thymidine incorporation. The intracellular calcium concentration ([Ca2+]i) was determined by Fura 2-fluorescence, and inositol 1,4,5-trisphosphate (1,4,5-IP3) concentration was measured by a radioreceptor assay. RESULTS: The data show that Lp(a) bound to the cells with a Kd of 17.0 micrograms/ml and increased DNA synthesis and cell proliferation. Lp(a) caused a rapid increase in 1,4,5-IP3 and [Ca2+]i via a pertussis toxin-sensitive mechanism. The phospholipase C (PLC) inhibitor U73122 abolished Lp(a)-induced cell proliferation. In contrast, vasopressin-induced increase in 1,4,5-IP3 and [Ca2+]i was pertussis toxin insensitive. CONCLUSION: This study revealed that Lp(a) stimulates growth of human mesangial cells. Lp(a)-induced signaling involves binding to a receptor and stimulation of PLC via Gi proteins. Stimulation of PLC appears to be essential for the growth stimulatory effect of Lp(a). Whether these effects of Lp(a) contribute to the pathophysiology of renal disease needs to be determined.     

Reducing Psychological Distress in Patients with Inflammatory Bowel Disease by Cognitive-Behavioural Treatment: Exploratory Study of Effectiveness

Background: This prospective study aimed to determine whether cognitive-behavioural group treatment accompanying medical standard care is effective in reducing psychological distress in patients with inflammatory bowel disease. Methods: Twenty-eight outpatients with Crohn disease or ulcerative colitis completed the treatment programme. Psychological treatment consisting of 12 weekly sessions was conducted in a group setting. Medical and psychometric assessments were taken at the beginning of the 3-month pretreatment waiting period, at pretreatment, at post-treatment and at the 3, 6 and 9-month follow-ups. Results: During baseline, no change was observed in psychological distress. Disease-related worries and concerns decreased significantly from pretreatment to the follow-ups. The disease groups differed in the decline of concerns between pre- and post-treatment, with a significant reduction of concerns in patients with ulcerative colitis but not Crohn disease. This difference did not occur at the follow-ups, indicating long-term improvement for both disease groups. Depressive coping decreased significantly in women and remained stable at the follow-ups, whereas depressive coping did not change in men. The same gender difference was found for depressive symptoms. Conclusions: The exploratory findings suggest that psychological group treatment for outpatients is a feasible and effective approach for the short- and long-term reduction of psychological distress for patients with inflammatory bowel disease. However, the revealed gender differences on coping and depression might indicate the necessity to consider gender-specific aspects of inflammatory bowel disease when designing and evaluating psychological interventions.