Lymphocyte proliferation and sister chromatid exchange in Alzheimer's disease.

Sister chromatid exchange (SCE) and lymphocyte proliferation were studied in peripheral lymphocyte cultures derived from 5 patients with Alzheimer disease (AD), 5 control elderly subjects and 5 young donors. These parameters did not differ significantly between the AD group and the elderly control group, but higher SCE frequency and less intensive proliferation were observed in the AD group and in the elderly control group when compared to the young donors.     

Hypoplasia of the Posterior Leaflet as a Rare Cause of Congenital Mitral Insufficiency

A bstract A rare case of congenital mitral insufficiency characterized by the hypoplasia of the posterior leaflet is reported. At operation, the mitral valve was successfully repaired by a ring annuloplasty, which created a satisfactory surface of coaptation between the anterior leaflet and the bulky posterior muscular structure. The presence of this posterior muscular structure represents a developmental arrest at the stage of conversion from muscular chordae and leaflets to thin connective structures.     

Fragile sites, Alzheimer's disease, and aging.

The fragile site expression under conditions of folate deprivation was compared in the chromosomes from 5 Alzheimer's disease (AD) female patients, 5 healthy elderly females and 5 healthy young females. Although different fragile sites were observed in the three groups, nevertheless, more similarities were found between the AD patients and elderly normal donors. The only fragile site common to all groups was 3p14. This site was the most frequent in the young donors group. In both AD and elderly control groups we observed a higher frequency of fragility in 6p21, but not in the young controls. Other interesting fragility points observed in these two groups were: 6q21 and 14q24 (in the AD patients) and 9q13, 14q24 and 17q21 (in the healthy aged). 6p21 and 17q21 have been proposed as 'new' fragile sites. We confirm the existence of these fragile sites and comment that in these bands the genes MTBT2 and MTBT1, which are microtubule (beta) associated protein tau-like and tau 1, respectively, are mapped. The tau protein is a component of paired helical filaments which accumulate in degenerating neurons in the brain of patients with AD and with less intensity of normal elderly individuals.     

Significance of PBMC response of rheumatic fever patients and control individuals to immunodominant streptococcal M5 protein epitopes

β-hemolytic streptococcal infection in developing countries still causes thousands of cases of Rheumatic Fever (RF). Molecular mimicry between streptococcal M protein (strep M) and heart components has been proposed as the triggering factor leading to autoimmunity in individuals with genetic susceptibility, which is linked to different HLA-DR alleles in different populations. In our hands, RF was significantly associated to HLA-DR7/53. Previous work in our lab has shown that heart-infiltrating T cells that simultaneously recognize strep M and heart proteins. Further, such T cells predominantly recognized the 81-103 strep M5 epitope. In this work, we analysed the proliferative response of peripheral blood mononuclear cells of 99 RF patients and 40 normal controls. Eighty-nine of the RF patients were HLA-typed. As among heart-infiltrating T cells, the 81-103 strep M5 protein epitope is the most frequently recognized epitope among RF PBMC (35.4%), against a 7.5% frequency of proliferation among normal controls (p=0.0018, chi square). However, the 81-103 epitope was as frequently recognized by HLA-DR7,53 positive as by negative individuals (45.2% vs 54.8%, respectively). Taken together, the results suggest that the 81-103 strep M5 epitope may be the immunodominant epitope, “promiscuously” recognized by T cells in a genetically diverse population. The demonstration that molecular mimicry is targeted to a discrete immunodominant “promiscuous” epitope in strep M5 may allow the development of a safe anti-streptococcal synthetic vaccine devoid of such epitopes.     

Myoid hamartomas of the breast: report of 3 cases and review of the literature

Hamartomas were first described by Albrecht in 1904, who defined them as tumor-like malformations in which there was abnormal blending of the normal components of an organ. The myoid hamartoma is a rare benign lesion of the breast and has an uncertain origin, possibly in the walls of the blood vessels, muscularis mammillae of the areolae, and mainly in myoepithelium. We report 3 cases of myoid hamartomas of the breast, with the clinical, radiologic, and histopathological findings, and review the literature. The 3 lesions showed normal breast ducts and lobules, entrapped by a muscular stroma and some foci of mature adipose tissue. The muscular origin of part of the stroma was confirmed by strong reactiveness with smooth-muscle actin.     

Development and Evaluation of an Interactive CD-ROM Refusal Skills Program to Prevent Youth Substance Use: “Refuse to Use”

An interactive CD-ROM program designed to reduce adolescent substance use was developed and evaluated. The program uses video vignettes to teach refusal skills and socially acceptable responses to substance use situations, specifically offers of marijuana. In a randomized pretest-to-posttest experiment with 74 public school students from six classes in three high schools, significant changes were observed at posttest on (1) the adolescent's personal efficacy to refuse the offer of marijuana, (2) the adolescent's intention to refuse marijuana if offered, and (3) the adolescent's perceptions of the social norms associated with substance use and the importance of respecting another's decision to refuse a drug offer. In addition, adolescents in the treatment condition were able to recall approximately 50% of the portrayed refusal strategies. Findings are discussed with regard to the potential benefits of an interactive multimedia approach for conducting substance use interventions.