Translocation (6;9)(p23;q34) in acute nonlymphocytic leukemia: Three new cases

Several recent reports have described cases of acute nonlymphocytic leukemia with a unique chromosome translocation, t(6;9)(p23;q34). We have studied three additional patients who have acute nonlymphocytic leukemia and t(6;9)(p23;q34). Our findings provide additional support for the suggestion that this translocation is yet another distinct cytogenetic abnormality associated with myeloproliferative disorders.     

DGGE-based whole-gene mutation scanning of the dystrophin gene in Duchenne and Becker muscular dystrophy patients

Duchenne and Becker muscular dystrophy (DMD and BMD) are caused by mutations in the dystrophin gene. Large rearrangements in the gene are found in about two-thirds of DMD patients, with approximately 60% carrying deletions and 5-10% carrying duplications. Most of the remaining 30-35% of patients are expected to have small nucleotide substitutions, insertions, or deletions. To detect these subtle changes within the coding and splice site determining sequences of the dystrophin gene, we established a semiautomated denaturing gradient gel electrophoresis (DGGE) mutation scanning system. The DGGE scan covers the dystrophin gene with 95 amplicons, PCRed either individually or in a multiplex setup. PCR and pooling were performed semiautomatically, using a pipetting robot and 384-well plates, enabling concurrent amplification of DNA of four patients in one run. Amplification of individual fragments was performed using one PCR program. The products were pooled just before gel loading; DGGE requires only a single gel condition. Validation was performed using DNA samples harboring 39 known DMD variants, all of which could be readily detected. DGGE mutation scanning was applied to analyze 135 DMD/BMD patients and potential DMD carriers without large deletions or duplications. In DNA from 25 out of 44 DMD patients (57%) and from 5 out of 39 BMD patients (13%), we identified clear pathogenic changes. All mutations were different, with the exception of one DMD mutation, which occurred twice. In DNA from 10 out of 44 potential DMD carriers, including four obligate carriers, we detected causative changes, including one pathogenic change in every obligate carrier. In addition to these pathogenic changes, we detected 15 unique unclassified variants, i.e., changes for which a pathogenic nature is uncertain.     

Comparison of colorimetric,fluorometric, and visual methods for determining anti-influenza (H1N1 and H3N2) virus activities and toxicities of compounds

Methods have been developed previously for rapid evaluation of compounds for antiviral activity in 96-well microplates, which include visual quantitation of antiviral activity based upon inhibition of virus-induced cytopathic effect (CPE) or by less subjective colorimetric or fluorometric means. In the present studies we compared a number of colorimetric (crystal violet, MTT [3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide], and neutral red) and fluorometric (Alamar Blue, bisbenzimide [Hoechst 33258], fluorescein diacetate, and rhodamine 6G) methods to visual scoring of antiviral activity in influenza A virus infections in Madin Darby canine kidney (MDCK) cells. Toxicity determinations using these same methods were also made for anti-influenza inhibitors and other compounds known to inhibit cell proliferation. Against influenza A/Texas/36/91 (H1N1) and A/Sydney/05/97 (H3N2) viruses, visual scoring and dye or stain methods produced results that were not significantly different from each other in deriving 50% virus-inhibitory concentrations (EC(50) values) for six anti-influenza compounds (amantadine, rimantadine, ribavirin, RWJ-270201 [BCX-1812], oseltamivir carboxylate, and zanamivir), with the exception of Alamar Blue which quantified lower EC(50) values than expected. In uninfected replicating cells, the visual and Alamar Blue methods underestimated the 50% cytotoxic concentrations (IC(50) values) of ribavirin, 1-beta-D-arabinofuranosylcytosine, and 6-azauridine, but more accurately assessed the toxicities of amantadine, rimantadine, and cycloheximide. Visual scoring, coupled with the use of one of these dyes or stains except Alamar Blue, can be used to accurately and rapidly quantify the anti-influenza virus activities and toxicities of potential new influenza virus inhibitors. These methods should also be applicable to evaluating antiviral effects against other lytic virus infections.     

Electrolyte Medium Effects on Measurements of Palmar Skin Potential

Two experiments with 12 subjects each compared skin potential recordings taken simultaneously with four different electrolytes. These were polyethylene glycol, hydrated agar (at a site presoaked with water), fresh agar (i.e., not presoaked), and Unibase. The glycol controlled epidermal hydration at a minimal level, while presoaking produced a high level of hydration at the hydrated agar site. Fresh agar and Unibase represented normal recording conditions for these two electrolytes which have been recommended as “standard” for electrodermal measurements. This design permitted a comparison of two standard electrolytes with each other and with recordings from hydrated and unhydrated sites. These comparisons were made for both monophasic negative SPRs and positive SPRs and the prestimulus levels associated with each. The results replicated previous studies in showing a large effect of epidermal hydration on skin potential measurements. Recordings with agar and Unibase did not differ significantly. The effects of hydration were interpreted in terms of a reduction in the resistance of the stratum corneum and of alterations in the functioning of the dermal and epidermal membranes as a result of blockage of the sweat gland pore. In the light of this interpretation, it was suggested that both agar and Unibase substantially alter the functioning of the sweat glands under some conditions, and neither may be entirely suitable for skin potential measurements.     

Single unit responses in the cervical sympathetic trunk upon somatic nerve stimulation

Pflügers Archiv - European Journal of Physiology -     

Quantitation of antigen-specific immune responses in human immunodeficiency virus (HIV)-infected individuals by limiting dilution analysis

The lymphocyte proliferative response to recall antigens is lost following HIV infection. We sought to devise a means by which the functional immune status of persons in the early stages of HIV infection could be monitored quantitatively. The response to tetanus toxoid was examined in 45 HIV-infected individuals and 11 controls using conventional lymphocyte proliferative assays concurrently with limiting dilution analysis utilizing the secretion of interleukin-2 as the measure of a response. Our data show that the limiting dilution analysis detects tetanus toxoid-reactive T cells in 80% of those tested, as compared to only 44% by proliferation. However, the frequency of tetanus-reactive T cells in HIV-infected individuals (median frequency = 1/59,156) is decrease five-fold as compared to seronegative controls (median frequency = 1/11,599). Longitudinal studies demonstrated a time-dependent decrease in the frequency of tetanus-specific T cell responses in the HIV-infected individuals. Thus, the limiting dilution analysis is a quantitative approach for detecting antigen-specific T cells in HIV-infected individuals, and may be used to monitor changes in T cell function in HIV infection.     

Discrepancies between self-reported years of education and estimated reading level among elderly community-dwelling African-Americans: Analysis of the MOAANS data.

The influence of education on cognition has received a great deal of attention in the literature. Although there is general consensus regarding the importance of education on cognitive functioning, the extent to which self-reported level of education corresponds to true educational attainment remains unclear, especially in ethnic minority populations where equal access to education has not always been available. Several investigators have suggested that reading skill may serve as a quantitative estimate of true education experience. Among African-Americans, however, research has shown that self-reported educational level consistently over predicts estimated reading level. The current study analyzed the discrepancy between self-reported years of education completed and estimated reading level in a sample of community-dwelling, elderly African-Americans participating in Mayo's Older African Americans Normative Studies (MOAANS) (Lucas, J.A., Ivnik, R.J., Willis, F.B., Ferman, T.J., Smith, G.E., Parfitt, F.C., Petersen, R.C., & Graff-Radford, N.R. (2005). Mayo's Older African Americans Normative Studies: Normative data for commonly used clinical neuropsychological measures. The Clinical Neuropsychologist, 19, 162-183). In this sample, 29% of the participants read at a level that was 3 or more years below what would be expected based on self-report of education attained. This study also sought to evaluate the extent to which this discrepancy fluctuated as a function of demographic variables such as location of schooling (urban, suburban, rural; North vs. South), parental education and literacy, and percentage of segregation in schooling. Implications of these results are discussed, as are areas for further inquiry.     

Intergeneration CAG expansion and contraction in a Chinese HD family.

The prevalence of juvenile-onset Huntington's disease (HD) is about ten times lower than adult HD. Here we report a Chinese HD family showing both intergeneration CAG expansion and contraction. The expansion resulted from a paternal transmission which leads to juvenile-onset HD for a 17-year-old Chinese boy (III-5). More interestingly, a contraction was noticed in a maternal transmission (III-3), which changed the CAG repeat from an expanded, disease-causing allele (48 repeats) to a normal or intermediate allele (34 repeats). Of note, the contraction resulted in a deletion of 14 CAG repeats, which is much larger than previously reported contractions. Our results are consistent with previous observations in Western Caucasians that juvenile-onset HD is more likely inherited through the male germline.