The 2,6-disubstituted naphthalene derivative FDDNP labeling reliably predicts Congo red birefringence of protein deposits in brain sections of selected human neurodegenerative diseases

Deposition of conformationally altered proteins prominently characterizes pathogenesis and pathomorphology of a number of neurodegenerative disorders. 2-(1-{6-[(2-[F-18]fluoroethyl) (methyl)amino]-2-naphthyl} ethylidene) malononitrile ([F-18]FDDNP), a hydrophobic, viscosity-sensitive, solvent-sensitive, fluorescent imaging probe has been used with positron emission tomography to visualize brain pathology in the living brain of Alzheimer disease (AD) patients. Its non-radiofluorinated analog FDDNP was shown to label senile plaques and neurofibrillary tangles (NFTs) in brain tissue sections. This work aimed at evaluating FDDNP labeling of various protein deposits in fixed, paraffin-embedded brain tissue sections of selected neurodegenerative disorders: AD, cerebral amyloid angiopathy (CAA), transmissible spongiform encephalopathies, progressive supranuclear palsy (PSP), Pick disease (PiD), Parkinson disease, dementia with Lewy bodies, multiple system atrophy (MSA). Cerebral hypertensive vascular hyalinosis (HVH) was used as negative control. Significant agreement between amyloid histochemical properties and FDDNP labeling of the deposits was established. FDDNP labeling showed high positive predictive value for birefringence in senile plaques and NFTs in AD, prion plaques and amyloid deposits in CAA. No FDDNP labeled structures were observed in HVH, PSP, PiD or MSA tissue sections. Our findings may be of significant value for the detection of neuropathological aggregates with [F-18]FDDNP in some of these disorders in the living brain of human subjects.     

Stability of BAT26 in tumours of hereditary nonpolyposis colorectal cancer patients with MSH2 intragenic deletion

Colon cancers arising in most patients with hereditary nonpolyposis colorectal cancer (HNPCC) show microsatellite instability (MSI). BAT26, a quasimonomorphic polyA stretch located just 3' of MSH2 exon 5, is considered the most sensitive and specific marker of MSI. A total of 10 HNPCC families with large intragenic MSH2 deletions, encompassing exon 5 and intron 5, identified by multiplex ligation-dependent probe amplification (MLPA) were included in this study. The deletions under study were del1-16, del1-8, del1-7, del1-6, and del3-6, detected in 3, 1, 2, 3, and 1 families, respectively. Although all patients examined from these 10 families developed unstable tumours, 13/19 MSI-H tumours (68 %) surprisingly showed stability of BAT26. By MLPA and MSH2 sequence analyses of the BAT26-stable tumours, we demonstrated that the wild-type MSH2 allele was somatically inactivated by an identical large deletion, with complete loss of intron 5/BAT26 sequences at the tumour DNA level. We could infer that the apparent stability of BAT26 was due to the complete absence of target BAT26 sequences in the tumour sample, which results in exclusive amplification of contaminant normal DNA, containing a single copy of a wild-type stable BAT26 sequence. Identification of a subset of MSH2-related unstable tumours that are not recognized by analysis of BAT26 instability indicates that this marker should never be used alone for rapid MSI screening of HNPCC tumours. Moreover, our findings indicate that BAT26 stability in the context of MSI is strongly suggestive of the presence of a large intragenic MSH2 deletion.     

Characterization of the Trypanosoma cruzi Rad51 gene and its role in recombination events associated with the parasite resistance to ionizing radiation

The Rad51 gene encodes a highly conserved enzyme involved in DNA double-strand break (DSB) repair and recombination processes. We cloned and characterized the Rad51 gene from Trypanosoma cruzi, the protozoan parasite that causes Chagas disease. This gene is expressed in all three forms of the parasite life cycle, with mRNA levels that are two-fold more abundant in the intracellular amastigote form. The recombinase activity of the TcRad51 gene product was verified by an increase in recombination events observed in transfected mammalian cells expressing TcRad51 and containing two inactive copies of the neomycin-resistant gene. As a component of the DSB repair machinery, we investigated the role of TcRad51 in the resistance to ionizing radiation and zeocin treatment presented by T. cruzi. When exposed to gamma irradiation, different strains of the parasite survive to dosages as high as 1 kGy. A role for TcRad51 in this process was evidenced by the increased expression of its mRNA after irradiation. Furthermore, transfected parasites over-expressing TcRad51 have a faster kinetics of recovery of the normal pattern of chromosomal bands after irradiation as well as a higher resistance to zeocin treatment than do wild-type cultures.     

Preprosthetic periodontal surgery in the proximal area with modification of the col area: results following the reestablishment of the contact point

BACKGROUND: Anatomic characteristics of interproximal areas are dependent on the anatomy, position, and proximal contact of adjacent teeth. The objective of this study was to investigate the influence of the reestablishment of the interproximal contact following the restorative alveolar interface (RAI) procedure on the interproximal gingival COL and formation of the interdental gingival papilla. METHODS: Six mongrel dogs received bilateral apically positioned flaps, crown lengthening, and the RAI procedure on the maxillary fourth bicuspid and first molar. After 2 weeks, in a randomized manner, one side was prepared to receive metallic crowns and the opposite side remained as the control. The crowns were cemented at the 4-week postoperative period, and the dogs were sacrificed after another 4 weeks, totaling a period of 4 weeks with the full crowns in position and a total of 8 postoperative weeks. Histologic specimens were stained with hematoxylin and eosin and Mallory dyes. Sections 6 micro m thick were obtained in a bucco-lingual plane allowing ample visualization of the interproximal area. RESULTS: Clinical measurements revealed that, in the restored sides, four animals had complete fill of the interdental spaces with gingival papilla, whereas the other two dogs had a distance from the contact point to the tip of papilla varying from 0.02 to 0.021 mm. In the control group, papillae were totally reepithelialized with keratinized epithelium and a convex form. The epithelium completely covered the connective tissue and showed both epithelial projections and surface desquamation. On the test group, despite the presence of the prosthesis, the COL morphology modified by preprosthetic surgery was not altered, presenting a convex papilla with a triangular form and with a keratinized epithelium. Additional histologic characteristics were the same as found in the control group. CONCLUSION: Based on the results of this study, the reestablishment of the contact point does not revert what was obtained with the RAI procedure; the interproximal tissues remain convex and keratinized.     

Interferon-gamma- and interleukin-4-producing T cells in Down's syndrome

Down's syndrome (DS) associates with genetic-dependent dysregulation of the interferon (IFN) system. We used intracellular cytokine staining to analyse the percentages of IFN-gamma- and interleukin (IL)-4-producing T cells in the peripheral blood of patients with DS, individuals with mental retardation (MR), and healthy controls (HCs). The percentages of IFN-gamma-producing CD4(+) and CD8(+) T cells (IFGCs), namely Th1 (mean, 21.4+/-S.D. 1.3) and Tc1 (12.6+/-1.1), and the Th1/Th2 ratio (6.1+/-0.2) in DS were significantly higher than in MR (15.9+/-1.3, 7.9+/-0.6, 4.8+/-0.3) and in HCs (15.6+/-1.9, 7.2+/-1.1, 4.6+/-0.6). Most of the DS patients with high IFGC percentages were seropositive for anti-transglutaminase IgA. We found no correlation between sex, age, APOE genotypes, coexisting autoimmune diseases, susceptibility to infections, or degree of cognitive impairment and high IFGC percentages. This abnormality might thus contribute to immune dysfunction in DS without manifest clinical correlates.     

How to follow communicative competence progress in nursing students

This work is aimed at suggesting methodological foundations for following Nursing student's progress in communicative competence. Using qualitative methodology and theoretical reference of interpersonal communication, the research was developed through interviews with 13 professors with experience both in teaching activities and communication research in Nursing. Interviewees reported that they follow their students' progress in communicative competence through the observation of their communicative abilities with patients; by fostering moments for the expression of thoughts, feelings and perceptions; by giving feedback on the development of communicative abilities; by stimulating their communication abilities; by performing formative assessments and tutoring.     

Radiotherapy increases the permissiveness of established mammary tumors to rejection by immunomodulatory antibodies

It is becoming increasingly evident that radiotherapy may benefit from coincident or subsequent immunotherapy. In this study, we examined whether the antitumor effects of radiotherapy, in established triple-negative breast tumors could be enhanced with combinations of clinically relevant monoclonal antibodies (mAb), designed to stimulate immunity [anti-(α)-CD137, α-CD40] or relieve immunosuppression [α-programmed death (PD)-1]. While the concomitant targeting of the costimulatory molecules CD137 and CD40 enhanced the antitumor effects of radiotherapy and promoted the rejection of subcutaneous BALB/c-derived 4T1.2 tumors, this novel combination was noncurative in mice bearing established C57BL/6-derived AT-3 tumors. We identified PD-1 signaling within the AT-3 tumors as a critical limiting factor to the therapeutic efficacy of α-CD137 therapy, alone and in combination with radiotherapy. Strikingly, all mice bearing established orthotopic AT-3 mammary tumors were cured when α-CD137 and α-PD-1 mAbs were combined with single- or low-dose fractionated radiotherapy. CD8+ T cells were essential for curative responses to this combinatorial regime. Interestingly, CD137 expression on tumor-associated CD8+ T cells was largely restricted to a subset that highly expressed PD-1. These CD137+PD-1High CD8+ T cells, persisted in irradiated AT-3 tumors, expressed Tim-3, granzyme B and Ki67 and produced IFN-γ ex vivo in response to phorbol 12-myristate 13-acetate (PMA) and ionomycin stimulation. Notably, radiotherapy did not deplete, but enriched tumors of functionally active, tumor-specific effector cells. Collectively, these data show that concomitant targeting of immunostimulatory and inhibitory checkpoints with immunomodulatory mAbs can enhance the curative capacity of radiotherapy in established breast malignancy.