[Intravenous infusion of adult adipose tissue stem cells for repairing spinal cord ischaemic lesions. An experimental study on animals]

OBJECTIVE

To assess if a peripheral intravenous infusion of adipose tissue stem cells (ATSC), after an ischemic spinal cord injury can promote selective cell migration and cell survival in the damaged neural tissue. ANIMALS AND METHOD: An ischaemic spinal cord injury was provoked by trapping the abdominal aorta for 20 minutes in 11 male New Zealand rabbits (2.5±0.5kg). They were randomised into two groups: one group (n=5) received an intravenous transfusion of 10±2×10(6) ATSC at 24 hours from the injury, and the control group (n=6) were only given the vehicle. The functional status was assessed, using the Tarlov scale at 24h, and 7 and 14 days. The animals were sacrificed at 14 days and a histological and immunohistochemical study was performed.

RESULTS

Complete paraplegia was achieved in both groups. There were no significant differences as regards neurological recovery, which was nil in both cases. In the histological and immunohistochemical study, it was tested to see if there was any bromodeoxyuridine-marked ATSC in the area of the lesion, but there was only a small amount.

CONCLUSION

ATSC are able to migrate and survive in the injured spinal cord after aortic ischaemia after they have been administered intravenously. Intravenous infusion is a harmless procedure with no side effect. No neurological recovery was achieved.

Interaction of emodin, aloe-emodin, and rhein with human serum albumin: a fluorescence spectroscopic study

The interaction of the dihydroxyanthraquinones, emodin (1), aloe-emodin (2), and rhein (3) with human serum albumin (HSA) has been studied through fluorescence spectroscopy. Quenching studies and the association constant of the anthraquinoid compounds 1, 2, and 3 in the presence of HSA were estimated. The binding and quenching studies suggest that only emodin (1) may serve as a useful fluorescence probe for structure/function studies of different emodin binding proteins. No photoinduced binding was observed after irradiation of compounds 1, 2, and 3 in presence of human serum albumin.

Herkogamy and mate diversity in the wild daffodil Narcissus longispathus: beyond the selfing-outcrossing paradigm in the evolution of mixed mating

Spatial separation of male and female reproductive structures (herkogamy) is a widespread floral trait that has traditionally been viewed as an adaptation that reduces the likelihood of self-pollination. Here we propose that increased herkogamy may also influence another important aspect of plant mating: the diversity of pollen donors siring seeds within fruits. We test this hypothesis in Narcissus longispathus, a wild daffodil species with extensive variation in anther-stigma separation. To study the morphological basis of variation in herkogamy, floral measurements were undertaken in 16 populations of N. longispathus. We then quantified multilocus outcrossing rates and the correlation of outcrossed paternity in three of these populations sampled over several years. Mating system estimates were calculated for each population and year, and also separately for groups of plants that differed markedly in herkogamy within each population and year. In N.  longispathus herkogamy was much more variable than other floral traits, and was more closely related to style length than to anther position. Averaged across populations and years, plants with high herkogamy had similar outcrossing rates (0.683) to plants with intermediate (0.648) or low herkogamy (0.590). However, a significant linear trend was found for correlation of outcrossed paternity, which increased monotonically from high herkogamy (0.221), through intermediate herkogamy (0.303) to low herkogamy (0.463) plants. The diversity of pollen donors siring seeds of high herkogamy Narcissus flowers was thus consistently greater than the diversity of pollen donors siring seeds of low herkogamy flowers. Results of this study contribute to the emerging consensus that floral traits can simultaneously influence several aspects of plant mating system in complex ways, thus extending the traditional focus centred exclusively on patterns and relative importance of self- and cross-fertilisation.

Essential gene profiles in breast, pancreatic, and ovarian cancer cells

Genomic analyses are yielding a host of new information on the multiple genetic abnormalities associated with specific types of cancer. A comprehensive description of cancer-associated genetic abnormalities can improve our ability to classify tumors into clinically relevant subgroups and, on occasion, identify mutant genes that drive the cancer phenotype ("drivers"). More often, though, the functional significance of cancer-associated mutations is difficult to discern. Genome-wide pooled short hairpin RNA (shRNA) screens enable global identification of the genes essential for cancer cell survival and proliferation, providing a "functional genomic" map of human cancer to complement genomic studies. Using a lentiviral shRNA library targeting ~16,000 genes and a newly developed, dynamic scoring approach, we identified essential gene profiles in 72 breast, pancreatic, and ovarian cancer cell lines. Integrating our results with current and future genomic data should facilitate the systematic identification of drivers, unanticipated synthetic lethal relationships, and functional vulnerabilities of these tumor types.

SIGNIFICANCE

This study presents a resource of genome-scale, pooled shRNA screens for 72 breast, pancreatic, and ovarian cancer cell lines that will serve as a functional complement to genomics data, facilitate construction of essential gene profiles, help uncover synthetic lethal relationships, and identify uncharacterized genetic vulnerabilities in these tumor types.

SIGNIFICANCE

This study presents a resource of genome-scale, pooled shRNA screens for 72 breast, pancreatic, and ovarian cancer cell lines that will serve as a functional complement to genomics data, facilitate construction of essential gene profiles, help uncover synthetic lethal relationships, and identify uncharacterized genetic vulnerabilities in these tumor types.

Exopolysaccharides produced by Lactobacillus and Bifidobacterium strains abrogate in vitro the cytotoxic effect of bacterial toxins on eukaryotic cells

AIMS

To evaluate the capability of the exopolysaccharides (EPS) produced by lactobacilli and bifidobacteria from human and dairy origin to antagonize the cytotoxic effect of bacterial toxins.

METHODS AND RESULTS

The cytotoxicity of Bacillus cereus extracellular factors on Caco-2 colonocytes in the presence/absence of the EPS was determined by measuring the integrity of the tissue monolayer and the damage to the cell membrane (extracellular lactate dehydrogenase activity). Additionally, the protective effect of EPS against the haemolytic activity of the streptolysin-O was evaluated on rabbit erythrocytes. The EPS produced by Bifidobacterium animalis ssp. lactis A1 and IPLA-R1, Bifidobacterium longum NB667 and Lactobacillus rhamnosus GG were able to counteract the toxic effect of bacterial toxins on the eukaryotic cells at 1mg ml(-1) EPS concentration. The EPS A1 was the most effective in counteracting the effect of B. cereus toxins on colonocytes, even at lower doses (0·5mg ml(-1) ), whereas EPS NB667 elicited the highest haemolysis reduction on erythrocytes.

CONCLUSIONS

The production of EPS by lactobacilli and bifidobacteria could antagonize the toxicity of bacterial pathogens, this effect being EPS and biological marker dependent.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work allows gaining insight about the mechanisms that probiotics could exert to improve the host health.

Electrophoretic mobility of silica particles in a mixture of toluene and ethanol at different particle concentrations

In this paper we present measurements of the electrophoretic mobility of colloidal particles by using heterodyne detection of light scattering. The measurements have been made up to concentrations of 5.4% silica nanoparticles, with a diameter on the order of 80 nm, in a mixture of 70% toluene and 30% ethanol. To make possible the measurements at these concentrations, the liquid mixture is chosen so as to match the index of refraction of the particles, thus resulting in a transparent suspension.

The geographic mosaic in predispersal interactions and selection on Helleborus foetidus (Ranunculaceae)

We examine the hierarchical geographic structure of the interaction between a plant, Helleborus foetidus, and its floral herbivores and pollinators (interactors). Six populations from three distant regions of the Iberian Peninsula were used to examine intra- and inter-regional variation in plant traits, interactors and plant fecundity, and to compare, through selection gradient and path analyses, which traits were under selection, and which interactors were responsible for differential selection. Geographic and temporal congruency in interactor-mediated selection was further tested using a recent analytical approach based on multi-group comparison in Structural Equation Models. Most plant traits, interactors and fecundity differed among regions but not between populations. Similarly, the identity of the traits under selection, the selection gradients (strength and/or the direction of the selection) and the path coefficients (identifying the ecological basis for selection) varied inter- but not intra-regionally. Results show a selection mosaic at the broad scale and, for some traits, a link of differential selection to trait differentiation.

Familial Alzheimer disease in Latinos: interaction between APOE, stroke, and estrogen replacement

BACKGROUND

Factors that modify risk related to APOE variants have been examined primarily in unrelated patients and controls, but seldom in family-based studies. Stroke, vascular risk factors, estrogen replacement therapy (ERT), head injury (HI), and smoking have been reported to influence risk of sporadic but not familial Alzheimer disease (AD).

OBJECTIVES

To examine the potential relationship between these risk factors and APOE, the authors used a family study design in a population in which the APOE-epsilon4 variant is strongly associated with risk of AD.

METHODS

Latino families primarily from the Caribbean Islands in which two or more living relatives had dementia were identified in the New York City metropolitan area, the Dominican Republic, and Puerto Rico. A total of 1,498 participants from 350 families underwent a clinical interview, medical and neurologic examinations, neuropsychological testing, and APOE genotyping. Diagnosis was made by consensus using research criteria for AD.

RESULTS

APOE-epsilon4 was associated with a nearly twofold increased risk of AD. A history of stroke was also associated with a fourfold increased risk. A statistical interaction between APOE-epsilon4 and stroke was observed. Women with an APOE-epsilon4 who took ERT did not have an increased risk of AD, but in women with a history of stroke ERT was a deleterious effect modifier.

CONCLUSIONS

APOE-epsilon4 and stroke independently increase risk of familial Alzheimer disease (AD) among Latinos, and may interact to further increase AD risk. Among women, the risk of AD associated with APOE-epsilon4 may be attenuated by a history of ERT.

Mating system, sex ratio, and persistence of females in the gynodioecious shrub Daphne laureola L. (Thymelaeaceae)

Although in gynodioecious populations male steriles require a fecundity advantage to compensate for their gametic disadvantage, southern Spanish populations of the long-lived shrub Daphne laureola do not show any fecundity advantage over hermaphrodites in terms of seed production and early seedling establishment. By using allozyme markers, we assess the mating system of this species in five populations differing in sex ratio, and infer levels of inbreeding depression over the whole life cycle by comparing the inbreeding coefficients at the seed and adult plant stages. Extremely low outcrossing rates (0.001<t<0.125) were consistently found for hermaphrodites in all populations, whereas, as expected, female progeny were entirely outcrossed. In most populations, offspring were much more inbred than their parents, and heterozygosity of adults was greater than expected from outcrossing rate estimates, with very few selfed progeny appearing to reproduce in the field. The combination of extensive selfing in hermaphrodites and a strong inbreeding depression expressed late in the life cycle (and thus, only estimable by indirect measures based on genetic markers) may explain the persistence and high frequency of D. laureola females in southern Spanish populations.

Fine mapping of 10q and 18q for familial Alzheimer's disease in Caribbean Hispanics

Familial Alzheimer's disease (AD [MIM 104300]) has been a focus of intense investigation, primarily in Caucasian families from Europe and North America families. Although the late-onset form of familial AD, beginning after age 65 years, has been linked to regions on chromosomes 10q and 12p, the specific genetic variants have not yet been consistently identified. Using a unique cohort of families of Caribbean Hispanics ancestry, we screened the genome using 340 markers on 490 family members from 96 families with predominantly late-onset AD. We observed the strongest support for linkage on 18q (LOD=3.14). However, 17 additional markers (chromosomes 1-6, 8, 10, 12, and 14) exceeded a two-point LOD score of 1.0 under the affecteds-only autosomal dominant model or affected sibpair model. As we previously reported the fine-mapping effort on 12p showing modest evidence of linkage, we focused our fine-mapping efforts on two other candidate regions in the current report, namely 10q and 18q. We added 31 family members and eight additional Caribbean Hispanic families to fine map 10q and 18q. With additional microsatellite markers, the evidence for linkage for 18q strengthened near 112 cM, where the two-point LOD score for D18S541 was 3.37 and the highest NPL score in that region was 3.65 (P=0.000177). This narrow region contains a small number of genes expressed in the brain. However, at 10q (134-138 cM), the NPL score decreased from 3.15 (P=0.000486) to 2.1 (P=0.0218), but two broad peaks remained overlapping with previously reported peaks. Our results provide modest support for linkage on 10q and 12p in this cohort of Caribbean Hispanic families with familial Alzheimer's disease, and strong evidence for a new locus on 18q.

Chromosome-12 mapping of late-onset Alzheimer disease among Caribbean Hispanics

Linkage to chromosome 12p for familial Alzheimer disease (AD) has been inconsistent. Using 35 markers near the centromere of chromosome 12, we investigated 79 Caribbean Hispanic families with AD. Two-point linkage analysis using affected sib pairs yielded LOD scores of 3.15 at D12S1623 and 1.43 at D12S1042. The LOD score at D12S1623 decreased to 1.62 in families with late-onset (age >65 years) AD (LOAD), but the LOD score at D12S1042 was unchanged. Among families negative for the apolipoprotein E (APOE-epsilon 4) allele, the LOD score for D12S1623 was lower (1.01), whereas that for D12S1042 increased to 1.73. Among families positive for the APOE-epsilon 4 allele, none of the LOD scores reached 1. Multipoint affected-relative-pair analysis showed peaks at D12S1623 (nonparametric linkage [NPL] score 1.52; P=.028) and near D12S1042, at D12S1057 (NPL score 1.57; P=.027). NPL scores for both D12S1623 and D12S1057 increased in families affected with LOAD, but, in APOE-epsilon 4-negative families, only scores for the region flanking D12S1623 remained elevated (NPL score 1.74; P=.013). This study of Caribbean Hispanics with familial AD extends and provides modest evidence of linkage to loci on chromosome 12p. Linkage varied by age at onset of AD and by the presence or absence of the APOE-epsilon 4 allele.

A founder mutation in presenilin 1 causing early-onset Alzheimer disease in unrelated Caribbean Hispanic families

CONTEXT

Genetic determinants of Alzheimer disease (AD) have not been comprehensively examined in Caribbean Hispanics, a population in the United States in whom the frequency of AD is higher compared with non-Hispanic whites.

OBJECTIVE

To identify variant alleles in genes related to familial early-onset AD among Caribbean Hispanics.

DESIGN AND SETTING

Family-based case series conducted in 1998-2001 at an AD research center in New York, NY, and clinics in the Dominican Republic.

PATIENTS

Among 206 Caribbean Hispanic families with 2 or more living members with AD who were identified, 19 (9.2%) had at least 1 individual with onset of AD before the age of 55 years.

MAIN OUTCOME MEASURE

The entire coding region of the presenilin 1 gene and exons 16 and 17 of the amyloid precursor protein gene were sequenced in probands from the 19 families and their living relatives.

RESULTS

A G-to-C nucleotide change resulting in a glycine-alanine amino acid substitution at codon 206 (Gly206Ala) in exon 7 of presenilin 1 was observed in 23 individuals from 8 (42%) of the 19 families. A Caribbean Hispanic individual with the Gly206Ala mutation and early-onset familial disease was also found by sequencing the corresponding genes of 319 unrelated individuals in New York City. The Gly206Ala mutation was not found in public genetic databases but was reported in 5 individuals from 4 Hispanic families with AD referred for genetic testing. None of the members of these families were related to one another, yet all carriers of the Gly206Ala mutation tested shared a variant allele at 2 nearby microsatellite polymorphisms, indicating a common ancestor. No mutations were found in the amyloid precursor protein gene.

CONCLUSIONS

The Gly206Ala mutation was found in 8 of 19 unrelated Caribbean Hispanic families with early-onset familial AD. This genetic change may be a prevalent cause of early-onset familial AD in the Caribbean Hispanic population.

Geographical variation in autonomous self-pollination levels unrelated to pollinator service in Helleborus foetidus (Ranunculaceae)

Autonomous self-pollination may be considered as a mechanism enhancing plant reproductive success when plant access to pollen sources may limit seed production. We have studied the relationship between geographical patterns of variation in pollinator service to Helleborus foetidus and self-pollination ability in three widely spaced regions in the Iberian Peninsula. As could be expected from its early flowering period, pollinator visitation rates to both plants and flowers of H. foetidus were very low at all sites. Pollinator composition remained consistent among regions, but there was significant variation among regions in pollinator service. Despite the low visitation rates, fruit set did not appear to be pollen limited in any of the study areas, which may be explained by the long duration of flowers (up to 20 d). When pollinators were excluded experimentally, fruit set decreased significantly, but substantial levels of self-pollination occurred at all regions. Autonomous self-pollination levels were lowest in the two regions with lowest pollinator service and highest in the region with highest pollinator service. This disagreement between our results and the expectations derived from the reproductive assurance hypothesis may reflect a nonequilibrium situation of the northern H. foetidus populations in relation to their current pollinating environment.

[Sjögren's syndrome and multiple sclerosis]

INTRODUCTION

Multiple sclerosis (MS) usually follows a relapsing-remitting course and attacks multiple areas of the central nervous system (CNS). Certain rheumatic diseases, including Sjögren's syndrome (SS), can present with a similar clinical picture.

RESULTS

Two patients out 67 of 100 with MS exhibited xerophthalmia and xerostomia and positive Ro antibodies, thus fulfilling 55 diagnostic criteria. Case 1. A 62-year-old woman developed several episodes of numbress and weakness in her left extremity and ataxia. MRI demonstrated a high-intensity areas in periventricular white matter. Initial laboratory studies failure to demonstrate antinuclear antibodies. Xerostomia and xerophthalmia were apparent. Follow-up laboratory examinations showed elevated ANA, Anti-SSA and anti-SSB. Case 2. A 58-year-old woman was diagnosed as having MS at the age of 53 years. Several high-signal foci on MRI were demonstrated in the white matter. Initial serum findings including autoantibodies were unremarkable. Sicca syndrome was present. Laboratory investigations included elevated anti-SSA, anti-SSARo52 and ANA while anti-SSB was within normal limits.

DISCUSSION

Primary SS is a chronic autoimmune inflammatory disease of unknown etiology. The CNS symptoms are present in 20-25% of the patients with SS. Some patients have a relapsing-remitting course mimicking MS. Focal brain lesions in SS can occur in the cerebral white matter. The features of our patients sufficiently mimicked those of MS and this disorder was the diagnosis in each patient at the time of initial evaluation. SS should be considered in th