Cystatin C, a cysteine protease inhibitor, is persistently up-regulated in neurons and glia in a rat model for mesial temporal lobe epilepsy

Cystatin C (CSTC), a cysteine protease inhibitor, has been implicated in the processes of neuronal degeneration and repair of the nervous system. Using serial analysis of gene expression (SAGE), we recently identified CSTC as one of the genes that are overexpressed after electrically induced status epilepticus (SE). In the present study, Western blot analysis extended the SAGE results, showing increased CSTC protein in the hippocampus and entorhinal cortex. Immunocytochemistry revealed an increase in CSTC expression in glial cells, which was first apparent 24 h after onset of SE, and persisted for at least 3 months. Double immunolabelling confirmed that both reactive astrocytes, and activated microglia were CSTC immunopositive. Within the hippocampus, up-regulation was also observed in neuronal cells within one day after SE. Up-regulation was still present in hippocampal pyramidal cells and surviving interneurons of chronic epileptic rats (3-8 months post-SE). This study demonstrates that status epilepticus leads to a widespread and persistent up-regulation of CSTC in the hippocampus and entorhinal cortex, which may represent an intrinsic neuroprotective mechanism in the course of epileptogenesis that may counteract progression of the disease.

Effect of adrenalectomy in kindled rats

It has previously been observed that adrenalectomy (ADX) increases the amplitude of transient Ca currents in CA1 hippocampal neurons. In the present study, the effect of ADX on cellular properties of CA1 neurons was investigated under conditions that challenge the CA1 network, i.e. in fully kindled rats, 5-6 weeks after the last kindling session. At this time, adrenally intact kindled rats showed, in comparison to non-kindled controls, a reduced population spike amplitude evoked in the CA1 area by Schaffer/commissural fiber stimulation, an increased amplitude of low-threshold, transient Ca currents and a decrease of the high-threshold, sustained Ca currents. As observed before, ADX in non-kindled rats increased the amplitude of transient Ca currents while sustained Ca currents were not affected. In kindled rats, ADX did not increase the transient Ca current amplitude beyond the level reached by kindling alone. The kindling-induced reduction of the sustained Ca current was partly normalized after ADX. Field responses of kindled rats were not affected by ADX. These data support the view that lack of adrenal hormones does not exacerbate but, to some extent, normalizes the kindling-induced changes in cellular properties and network function of the CA1 area. The hormonal effects on kindling may be reciprocal in nature, since kindling, in turn, was found to affect the stress response and the corticosteroid receptor mRNA expression in the hippocampus.

Effects of repeated annual influenza vaccination on vaccine sero-response in young and elderly adults

Three cohort studies in adults were performed during the period from 1986 to 1989. Eight hundred and eighty-four subjects were, one or more times, immunized with influenza vaccines, and pre- and post-vaccination antibody titres were determined by hemagglutination inhibition tests. One thousand and one hundred and nineteen vaccination events in 681 subjects could be analysed by a comparison, per trial and per influenza (sub)type, between groups with and without influenza vaccination in previous years. Effect size, odds ratio and protection rate difference, were used as effect measures. Subjects with previous vaccination showed higher pre-vaccination antibody than those without. The average change of the post-vaccination proportion of subjects with high antibody titre value to previous vaccination, was +9.4% (95% CI: +5.3 to 13.6%) for A-H3N2 vaccine components, -2.1% (-8.1 to 3.9%, not significant) for A-H1N1 and -10.6% (-16.5% to -4.8%) for B. In a linear regression model, pre-vaccination titres and the status of previous vaccination were identified as factors significantly influencing post-vaccination titres. These findings are discussed in the context of a short review of the literature. It is concluded that the status of previous vaccination should always be addressed as an independent factor in serological vaccination studies.

Adjuvancy and reactogenicity of N-acetylglucosaminyl-N-acetylmuramyl-dipeptide (GMDP) orally administered just prior to trivalent influenza subunit vaccine. A double-blind placebo-controlled study in nursing home residents

One hundred and fifty-three nursing home residents received 0, 5, 25 or 50 mg N-acetylglucosaminyl-N-acetylmuramyl-dipeptide (GMDP) orally, and trivalent influenza subunit vaccine intramuscularly. One day after intervention, there was a strong increase of total leucocytes, monocytes and neutrophils in the groups receiving 25 or 50 mg GMDP. A GMDP dose dependent increase in systemic, but not in local, vaccine side-effects was observed. No significant differences in post-vaccination haemagglutination inhibiting serum antibody titres were observed between the four groups, indicating that oral administration of GMDP together with influenza vaccination, does not lead to a higher vaccine efficacy.

Isozyme specific changes in the expression of protein kinase C isozyme (alpha-zeta) genes in the hippocampus of rats induced by kindling epileptogenesis

The transcript levels of the protein kinase C (PKC) isoform genes during the development of a kindled epileptogenic focus, elicited by stimulation of Schaffer collateral/commissural fibres in the CA1 area of the rat hippocampus, were compared with the expression levels in control animals using a semi-quantitative in situ hybridization approach. In the hippocampus of control animals, the levels of PKC-alpha-zeta transcripts showed a gene-specific expression pattern and significant differences in expression level were observed between the neurons of CA1, CA3 and fascia dentata. In the early stages of kindling epileptogenesis, i.e. following 6 and 14 afterdischarges, specific changes in the expression levels of PKC-beta, -epsilon, and -zeta but not of PKC-alpha, -gamma, and -delta were found. PKC-beta expression was decreased in CA1, while the PKC-epsilon and -zeta specific hybridization signals were increased in CA1, CA3 and fascia dentata. In fully kindled animals, that had experienced 10 generalized seizures, most expression levels tended to return to control values. One month after the last seizure no significant alterations were encountered. These results indicate an involvement of specific PKC-isoform gene expression in the induction of an epileptogenic focus, but not in the maintenance of the long-lasting kindled state.

HSV-2 replication sites, monocyte and lymphocytic cell infection and virion phagocytosis by neutrophils, in vesicular lesions on penile skin. Electronoptical studies of a biopsy

From a heterosexual male with recurrent genital herpes simplex virus (HSV-2) infection, a fresh intraepidermal vesicle on the penile skin was excised by punch biopsy, fixed and processed for electron microscopy. Differing locations and appearances of capsids and virions were studied to elucidate true host or destroyer cells. HSV-2 propagation and virion formation occurred predominantly in multi- or mononucleate spinosum cells situated at the base of the vesicle. However, some of the monocytes, young histiocytes and lymphocytic cells floating in the vesicle fluid were also involved. They harbored a small number of intranuclear capsids, designating the cells as viral (capsid) carriers. Infrequently encountered free virions in the vesicle fluid were invariably seen near neutrophils. All neutrophil granulocytes examined lacked intranuclear capsids. In contrast, distinct evidence of phagocytosis of virions and some capsids by neutrophils was found in the vesicle fluid near apical portions of spinosum cells packed with virions, or in neutrophils located between virion-loaded spinosum cells in the base lining of the vesicle. In the cytoplasm of neutrophils, single and lysosome-enclosed clusters of virions were noted. Myelin figures and vacuolation of lysosomes in free-floating neutrophils were suggestive of virion distintegration. Viral propagation and abundant virion formation, beside neutrophil and lymphocyte attack, eventually lead to spinosum cell destruction. The minimal cytopathic effects (CPE) observed in involved monocytes and lymphocytic cells floating in the vesicle fluid suggest that these cells might function as vehicles for HSV-2 (capsid) transport to the exterior or interior.