Interface echos between the retina and choroid

In 61 patients echographically examined in A and AB mode at Münster University Eye Hospital a membrane-like echo was found between the retina and the choroid. The acoustic characteristics were studied. The usefulness for the differential diagnosis of retinal detachment was demonstrated with several situations of the retina. The thickness of the retina and choroid can be measured in routine examinations.     

Nipple centralization for the correction of breast deformity from segmental mastectomy

A breast deformed by lateral tissue deficiency and severe lateral displacement of the nipple, caused by the treatment of an early breast cancer with segmental mastectomy and radiotherapy, was corrected by a modification of techniques used commonly for mastopexy. The nipple and areola were moved medially on a central pedicle to create the illusion that the missing lateral tissues had been restored. Simultaneously, the opposite breast was reduced to improve symmetry. The result was a normalization of breast appearance without the need for distant tissue. It is possible that modifications of this approach could be used to treat similar deformities in other quadrants of the breast as well.     

An AscI boundary library for the studies of genetic and epigenetic alterations in CpG islands

Knudson's two-hit hypothesis postulates that genetic alterations in both alleles are required for the inactivation of tumor-suppressor genes. Genetic alterations include small or large deletions and mutations. Over the past years, it has become clear that epigenetic alterations such as DNA methylation are additional mechanisms for gene silencing. Restriction Landmark Genomic Scanning (RLGS) is a two-dimensional gel electrophoresis that assesses the methylation status of thousands of CpG islands. RLGS has been applied successfully to scan cancer genomes for aberrant DNA methylation patterns. So far, the majority of this work was done using NotI as the restriction landmark site. Here, we describe the development of RLGS using AscI as the restriction landmark site for genome-wide scans of cancer genomes. The availability of AscI as a restriction landmark for RLGS allows for scanning almost twice as many CpG islands in the human genome compared with using NotI only. We describe the development of an AscI-EcoRV boundary library that supports the cloning of novel methylated genes. Feasibility of this system is shown in three tumor types, medulloblastomas, lung cancers, and head and neck cancers. We report the cloning of 178 AscI RLGS fragments via two methods by use of this library.     

Geminin regulates neuronal differentiation by antagonizing Brg1 activity

Precise control of cell proliferation and differentiation is critical for organogenesis. Geminin (Gem) has been proposed to link cell cycle exit and differentiation as a prodifferentiation factor and plays a role in neural cell fate acquisition. Here, we identified the SWI/SNF chromatin-remodeling protein Brg1 as an interacting partner of Gem. Brg1 has been implicated in cell cycle withdrawal and cellular differentiation. Surprisingly, we discovered that Gem antagonizes Brg1 activity during neurogenesis to maintain the undifferentiated cell state. Down-regulation of Gem expression normally precedes neuronal differentiation, and gain- and loss-of-function experiments in Xenopus embryos and mouse P19 cells demonstrated that Gem was essential to prevent premature neurogenesis. Misexpression of Gem also suppressed ectopic neurogenesis driven by Ngn and NeuroD. Gem's activity to block differentiation depended upon its ability to bind Brg1 and could be mediated by Gem's inhibition of proneural basic helix-loop-helix (bHLH)-Brg1 interactions required for bHLH target gene activation. Our data demonstrate a novel mechanism of Gem activity, through regulation of SWI/SNF chromatin-remodeling proteins, and indicate that Gem is an essential regulator of neurogenesis that can control the timing of neural progenitor differentiation and maintain the undifferentiated cell state.     

Lipopolysaccharide-Based Enzyme-Linked Immunosorbent Assay for Experimental Use in Detection of Antibodies to Lawsonia intracellularis in Pigs

An enzyme-linked immunosorbent assay (ELISA) for Lawsonia intracellularis was developed and compared with a whole-cell antigen-based immunofluorescence antibody test (IFAT). The antigen-containing lipopolysaccharide (LPS) was derived from Percoll gradient purified cultures of L. intracellularis by using a modification of the Westphal hot phenol procedure. The antigen was bound directly to polystyrene 96-well microtiter plates, and the assay was performed in an indirect ELISA format. Specificity and sensitivity values based on 80 known positive and 80 known negative serum samples from controlled experimental trials were 93.7% and 88.7%, respectively. Serological results from a controlled L. intracellularis challenge exposure study confirmed the high specificity and sensitivity of this assay (100% and 99.5%, respectively). Comparisons between the LPS ELISA and the IFAT in detecting anti-Lawsonia antibodies in this controlled study revealed significantly more LPS ELISA-positive pigs than IFAT-positive pigs on days 21, 28, 35, and 42 (P = 0.003, 0.030, 0.002, and 0.006, respectively). This indirect ELISA (LPS ELISA) test is an improved method of detecting antibodies in pigs soon after exposure to L. intracellularis, regardless of isolate type (vaccine or wild type) in experimental studies. The LPS ELISA may be used as a tool to support future research trials on vaccine efficacy and to further understand the immune response induced by L. intracellularis.     

Isolation and separation of physicochemically distinct fimbrial types expressed on a single culture of Escherichia coli O7:K1:H6.

The fimbrial (pili) profile of a single strain of Escherichia coli O7:K1:H6 (WF96) was evaluated. Fimbriae were isolated by sucrose density gradient ultracentrifugation, purified from flagellae by the use of 0.4% sodium dodecyl sulfate (SDS), and separated into distinct fimbrial types. Analysis of the purified WF96 fimbriae by SDS-polyacrylamide gel electrophoresis revealed two polypeptide bands with molecular weights of 16,000 and 21,000. Treatment of the fimbrial mixture with saturated guanidine hydrochloride resulted in the appearance of a third band with a molecular weight of 19,500. The relative susceptibilities of the WF96 fimbrial types to disrupting chemicals (octyl-glucoside, urea, SDS, and guanidine hydrochloride) were assessed by exposure of the fimbrial mixture to each agent, separation of the depolymerized fimbriae from intact fimbriae by gel filtration on Sepharose CL-4B, and identification of the disaggregated fimbrial types by SDS-polyacrylamide gel electrophoresis of column fractions. The physicochemical heterogeneity of the three fimbrial types coexpressed on WF96 was exploited to develop a method for separation of individual fimbriae.     

Correlation between clinical scoring of allergic patch test reactions and optical coherence tomography

Noninvasive imaging techniques might be of particular diagnostic value for studying and monitoring cutaneous inflammatory conditions such as contact dermatitis. We evaluate acute allergic contact dermatitis (AACD) by means of optical coherence tomography (OCT) and correlate the clinical grading of patch test reactions with the findings obtained from OCT. Twenty positive patch test reactions (+, n = 6; ++, n = 7; +++, n = 7) are investigated using a conventional OCT scanner. In comparison to the control sites, OCT of AACD showed pronounced skin folds, thickened and/or disrupted entrance signals, and a significant increase in epidermal thickness. Moreover, clearly demarcated signal-free cavities within the epidermis and considerable reduction of dermal reflectivity are demonstrated by OCT. Notably, the latter findings strongly correlate with the clinical patch test grading. OCT may be a useful tool for visualization of micromorphological features of AACD. However, before OCT can be employed as an objective parameter in grading severity of patch test reactions, larger studies are required that correlate clinical patch test readings and OCT findings with histopathology.     

Effects of prior polysaccharide vaccination on magnitude, duration, and quality of immune responses to and safety profile of a meningococcal serogroup C tetanus toxoid conjugate vaccination in adults

Extensive use of meningococcal AC polysaccharide (MACP) vaccines has raised concerns about induction of immunologic hyporesponsiveness to C polysaccharide. We investigated the immunogenicity and safety of a meningococcal C-tetanus conjugate (MCC-TT) vaccine in naive adults and prior MACP vaccinees. Laboratory staff (n = 113) were recruited; 73 were naive to meningococcal vaccination, and 40 had previously received > or =1 dose of MACP vaccine. Blood was taken prior to MCC-TT vaccination and 1 week, 1 month, and 6 months later. At each time point, proportions of subjects with serum bactericidal antibody (SBA) titers of > or =8 or > or =128 were similar (P > 0.46); >94% of subjects achieved titers of > or =128 at 1 month. However, the geometric mean titer (GMT) of SBA at 1 month was higher in the naive (1,757; 95% confidence interval [95% CI], 1,102 to 2,803) than in the previously vaccinated (662; 95% CI, 363 to 1,207) group (P = 0.02), and similarly at 6 months (P < 0.001). Conversely, geometric mean concentrations (GMCs) of serogroup C-specific immunoglobulin G (IgG) were significantly higher in the previously vaccinated group pre-MCC-TT and at 1 week; the groups were similar at 1 month, and there was some evidence that the GMC for the previously vaccinated group was higher at 6 months. Qualitative differences in antibodies between groups were demonstrated by using the SBA/IgG ratio, though avidity measures were similar for the two groups throughout the study. MCC-TT was well tolerated, with similar safety profiles in the two groups. Pain in the arm and headache were the most frequently reported events following vaccination. The study shows that MCC-TT is safe and immunogenic in naive and previously MACP-vaccinated adults, though the magnitude and persistence of postvaccination SBA responses in the latter group were lower.