Human corneal epithelial equivalents constructed on Bombyx mori silk fibroin membranes

Membranes prepared from a protein, fibroin, isolated from domesticated silkworm (Bombyx mori) silk, support the cultivation of human limbal epithelial (HLE) cells and thus display significant potential as biomaterials for ocular surface reconstruction. We presently extend this promising avenue of research by directly comparing the attachment, morphology and phenotype of primary HLE cell cultures grown on fibroin to that observed on donor amniotic membrane (AM), the current clinical standard substrate for HLE transplantation. Fibroin membranes measuring 6.3 ± 0.5 μm (mean ± sd) in thickness and permeable to FITC dextran of a molecular weight up to 70 kDa, were used. Attachment of HLE cells to fibroin was similar to that supported by tissue culture plastic but approximately 6-fold less than that observed on AM. Nevertheless, epithelia constructed from HLE on fibroin maintained evidence of corneal phenotype (K3/K12 expression) and displayed a comparable number and distribution of ΔNp63(+) progenitor cells to that seen in cultures grown on AM. These results support the suitability of membranes constructed from Bombyx mori silk fibroin as substrata for HLE cultivation and encourage progression to studies of efficacy in preclinical models.     

No evidence for allelic association between schizophrenia and a functional variant of the human dopamine β-hydroxylase gene (DBH)

Dopamine β-hydroxylase (DBH), the enzyme that converts dopamine to norepinepherine, has been proposed as being involved in the aetiology of schizophrenia. Previous work identified a functional polymorphism at nucleotide 910 of the DBH gene that results in a codon change in the mature protein Ala304Ser, with the mutant allele being associated with a lower enzymatic activity. In this study we performed an RFLP analysis in an association study consisting of 178 unrelated schizophrenic patients and 178 unrelated control subjects, matched for age, sex, and ethnicity. The frequency of the Ser304 DBH allele was 0.10 in the patient group and 0.08 in the control group, with no significant allelic or genotypic association observed. Therefore, we were unable to obtain evidence that this polymorphism contributes directly to susceptibility to schizophrenia. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:557–559, 1999. © 1999 Wiley-Liss, Inc.     

Evaluation of tick-borne encephalitis DNA vaccines in monkeys.

Tick-borne encephalitis is usually caused by infection with one of two flaviviruses: Russian spring summer encephalitis virus (RSSEV) or Central European encephalitis virus (CEEV). We previously demonstrated that gene gun inoculation of mice with naked DNA vaccines expressing the prM and E genes of these viruses resulted in long-lived homologous and heterologous protective immunity (Schmaljohn et al., 1997). To further evaluate these vaccines, we inoculated rhesus macaques by gene gun with the RSSEV or CEEV vaccines or with both DNA vaccines and compared resulting antibody titers with those obtained by vaccination with a commercial, formalin-inactivated vaccine administered at the human dose. Vaccinations were given at days 0, 30, and 70. All of the vaccines elicited antibodies detected by ELISA and by plaque-reduction neutralization tests. The neutralizing antibody responses persisted for at least 15 weeks after the final vaccination. Because monkeys are not uniformly susceptible to tick-borne encephalitis, the protective properties of the vaccines were assessed by passive transfer of monkey sera to mice and subsequent challenge of the mice with RSSEV or CEEV. One hour after transfer, mice that received 50 microl of sera from monkeys vaccinated with both DNA vaccines had circulating neutralizing antibody levels <20-80. All of these mice were protected from challenge with RSSEV or CEEV. Mice that received 10 microl of sera from monkeys vaccinated with the individual DNA vaccines, both DNA vaccines, or a commercial vaccine were partially to completely protected from RSSEV or CEEV challenge. These data suggest that DNA vaccines may offer protective immunity to primates similar to that obtained with a commercial inactivated-virus vaccine.     

In vitro immunomodulatory properties of tucaresol in HIV infection

The immunomodulatory properties of tucaresol (compound 589C80) were tested on in vitro antigen- and mitogen-stimulated proliferation and cytokine production by peripheral blood mononuclear cells (PBMC) of HIV-infected individuals and healthy controls (HC). Results showed that tucaresol: (1) increases influenza A virus-, gp 160 peptide-, and HLA alloantigen-stimulated proliferation as well as interleukin (IL)-2 and interferon gamma (IFN gamma) production by PBMC of HIV-infected individuals with higher CD4 counts (>500/microl) but had only a marginal immunomodulatory effect on PBMC of patients with lower CD4 counts (<500/microl); (2) did not modify IL-10 production; (3) augmented CD25 expression on mitogen-stimulated T cells of HC but not of HIV-infected individuals; and (4) marginally increased CTL activity. The immunomodulatory properties of tucaresol were confirmed by PCR analyses; additional data showed that tucaresol costimulated CD3-dependent triggering of T cells and that this stimulation was independent of CD28 costimulation. The immunomodulatory effects of tucaresol on T cell functions are characterized by a bell-shaped dose response curve; the action of the compound is optimal in the 100 to 300 microM range. Analyses of mitogen-stimulated apoptosis demonstrated that the lack of effect of tucaresol at higher doses is not the result of increased cell death, suggesting a role of functional impairment. These data confirm that tucaresol can stimulate T helper cell function and enhance the production of type 1 cytokines, thus eliciting cell-mediated immunity, and warrant its potential utility in the therapy of HIV infection.     

Infection of cynomolgus macaques with a recombinant monkeypox virus encoding green fluorescent protein

Monkeypox virus (MPXV) causes a vesiculopustular rash illness resembling smallpox in humans and produces a similar disease in nonhuman primates. To enhance the ability of researchers to study experimental MPXV infections, we inserted a gene encoding green fluorescent protein (GFP) into Monkeypox virus Zaire-79. Wild-type and MPXV-GFP replicated with similar kinetics in cell culture and caused a similar disease when injected intravenously into cynomolgus macaques. In MPXV-GFP-infected animals, examination under fluorescent light facilitated the identification of skin lesions during disease development and internal sites of replication at necropsy. MPXV-GFP could improve the quantitative assessment of antiviral therapy and vaccine efficacy.     

Depressive Symptoms Among Children and Adolescents in Iran: A Confirmatory Factor Analytic Study of the Centre for Epidemiological Studies Depression Scale for Children

This study investigated the psychometric properties of the Iranian translation of the Centre for Epidemiological Studies Depression Scale for Children (CES-DC) in school children and adolescents in Iran. The CES-DC is a 20-item self-report scale designed to measure depressive symptoms in children and adolescents. A total of 1,984 children and adolescents, aged 12–17 years, participated in this research. In addition to the CES-DC, all participants completed the Spence Children’s Anxiety Scale (SCAS) and the Strength and Difficulties Questionnaire (SDQ). The CES-DC demonstrated high internal consistency (Cronbach Alpha = .87). Confirmatory factor analyses revealed the same four factor structure as proposed by Radloff. Invariance tests showed an equivalent structure among boys and girls and younger and older adolescents. The CES-DC total scores correlated significantly with the SCAS total scores and the SDQ emotional symptoms subscale, providing support of its convergent validity. To conclude, the CES-DC proved to be a reliable and valid measure of depressive symptoms in the Iranian context.     

Comparison of the structure of human intervertebral discs in the cervical,thoracic and lumbar regions of the spine

Posterior and anterior heights, cross-sectional area and shape were measured for all the intervertebral discs in four spines from elderly human cadavers. Disc height was a minimum at the T4-5 level; thoracic discs were less wedge-shaped than those in the cervical and lumbar regions. Cross-sectional area increased from the cranial to caudal extremity; at the L5-S1 level the nucleus pulposus occupied a high proportion of this area. Cervical discs tended to have an elliptical cross-sectional shape, thoracic discs were more circular and lumbar discs tended to have an elliptical cross-section which was flattened or re-entrant posteriorly. This shape distribution was quantified by defining a shape index which had a maximum value of 1 for a circular cross-section. Orientations of the reinforcing fibres in the outer lamellae of the anterior annulus fibrosus were measured from 27 discs by X-ray diffraction. For these measurements, C3-4, T7-8 and L2-3 were chosen as representative of cervical, thoracic and lumbar discs. The fibre tilt, with respect to the axis of the spine, was significantly less in the cervical discs (at 65 degrees) than in the thoracic and lumbar discs (about 70 degrees). These findings are interpreted in relation to differing functional requirements and possible mechanisms of failure in the cervical, thoracic and lumbar regions of the spine in the light of current knowledge on the biomechanics of the intervertebral disc.     

Low levels of polymorphism at novel microsatellite loci developed for bathyergid mole-rats from South Africa

Eight microsatellite markers were developed for African mole-rats using the Fast Isolation by AFLP of Sequences Containing repeats (FIASCO) protocol and pyrosequencing. The markers were developed in Bathyergus suillus and applied to a selection of individuals from seven related taxa: Bathyergus janetta, Cryptomys hottentotus hottentotus, C. h. pretoriae, Fukomys damarensis, F. darlingi, F. mechowii and Georychus capensis. The markers displayed low to moderate variation with allele numbers ranging between one and six per species. We propose that larger repeat numbers at di-, tri- and tetranucleotide repeat loci generally yield higher levels of polymorphism.     

New universal precaution aspiration tray

A new tray has been designed for use during procedures involving needles and other sharp objects. The tray includes a foam adhesive pad, marked into 10 sections, into which the sharp objects can be placed point first. After the procedure, the objects can be safely withdrawn by their handles and then discarded. The tray has been used in more than 250 procedures.