1,028 research outputs found
Confidence Intervals for Long Memory Regressions
This paper proposes an accurate confidence interval for the trend parameter in a linear regression model with long memory errors. The interval is based upon an equivalent sum of squares method and is shown to perform comparably to a weighted least squares interval. The advantages of the proposed interval lies in its relative ease of computation and should be attractive to practitioners
Higher populationābased incidence rates of tripleānegative breast cancer among young AfricanāAmerican women
BACKGROUND: Differences in the breast cancer burden of AfricanāAmerican women compared with white American women are well documented. Recent controversies have emerged regarding ageāappropriate mammographic screening guidelines, and these surveillance recommendations may influence future breast cancer disparities. The objective of the current study was to evaluate ageāspecific breast cancer stage distributions and incidence rates of tripleānegative breast cancer (TNBC) in a populationābased tumor registry. METHODS: The authors analyzed breast cancers from the California Cancer Registry (CCR) that were diagnosed between 1988 and 2006. The results were stratified by age and race/ethnicity, with white Americans identified as nonāHispanic whites (NHWs) and African Americans identified as nonāHispanic blacks (NHBs). Breast cancer stage distributions and TNBC incidence rates also were analyzed. RESULTS: In total, 375,761 invasive breast cancers were evaluated (including 276,938 in NHWs and 21,681 in NHBs). NHBs and Hispanics tended to be younger than NHWs (median ages 57 years, 54 years, and 64 years, respectively). Lifetime incidence rates were higher for NHWs compared with NHBs and Hispanics; however, for women aged <44 years, incidence was highest among NHBs. NHBs also had higher incidence rates of stage III and IV disease and a higher incidence of TNBC in all age categories. CONCLUSIONS: Populationābased data demonstrated that AfricanāAmerican women had a more advanced stage distribution for breast cancer compared with white American women and higher incidence rates for TNBC. These patterns were observed for women ages 40 to 49 years and for older women, and they suggest that mammographic screening for the early detection of breast cancer will be particularly relevant for younger AfricanāAmerican women. Cancer 2011. Ā© 2011 American Cancer Society. The California Cancer Registry revealed higher populationābased incidence rates of early onset, advancedāstage, and tripleānegative breast cancer for AfricanāAmerican women compared with white American women. These findings suggested that mammographic screening will be particularly important for young AfricanāAmerican women.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87175/1/25862_ftp.pd
Histological Review of Skin cancers in African Albinos: A 10-year Retrospective Review.
Skin cancer is rare among Africans and albinism is an established risk for skin cancer in this population. Ultraviolet radiation is highest at the equator and African albinos living close to the equator have the highest risk of developing skin cancers. This was a retrospective study that involved histological review of all specimens with skin cancers from African albinos submitted to The Regional Dermatology Training Center in Moshi, Tanzania from 2002 to 2011. A total of 134 biopsies from 86 patients with a male to female ratio of 1:1 were reviewed. Head and neck was the commonest (nā=ā75, 56.0%) site affected by skin cancers. Squamous cell carcinoma (SCC) was more common than basal cell carcinoma (BCC) with a ratio of 1.2:1. Only one Acral lentiginous melanoma was reported. Majority (55.6%) of SCC were well differentiated while nodular BCC (75%) was the most common type of BCC. Squamous cell carcinoma is more common than basal cell carcinoma in African albinos
High-Performance Piezoresistive MEMS Strain Sensor with Low Thermal Sensitivity
This paper presents the experimental evaluation of a new piezoresistive MEMS strain sensor. Geometric characteristics of the sensor silicon carrier have been employed to improve the sensor sensitivity. Surface features or trenches have been introduced in the vicinity of the sensing elements. These features create stress concentration regions (SCRs) and as a result, the strain/stress field was altered. The improved sensing sensitivity compensated for the signal loss. The feasibility of this methodology was proved in a previous work using Finite Element Analysis (FEA). This paper provides the experimental part of the previous study. The experiments covered a temperature range from ā50 Ā°C to +50 Ā°C. The MEMS sensors are fabricated using five different doping concentrations. FEA is also utilized to investigate the effect of material properties and layer thickness of the bonding adhesive on the sensor response. The experimental findings are compared to the simulation results to guide selection of bonding adhesive and installation procedure. Finally, FEA was used to analyze the effect of rotational/alignment errors
Inhibitory effects of interleukin-10 plasmid DNA on the development of atopic dermatitis-like skin lesions in NC/Nga mice
Interleukin (IL)-10 exerts potent anti-inflammatory effects by suppression of both T-help (Th) 1 and Th2 cells. Previous studies have reported that IL-10 can ameliorate various inflammatory disorders. The present study was performed to examine whether IL-10 plasmid DNA could suppress development of atopic dermatitis (AD)-like skin lesions in NC/Nga mice, as an initial step towards the development of an appliance for use in dogs with AD. Intradermal injection of IL-10 plasmid DNA markedly inhibited the development of AD-like skin lesions, as evidenced by a marked decrease in skin symptoms and reduced inflammation within the skin lesions. Efficacy was confirmed by significant decreases in eosinophil ratio and serum IgE concentration, and a reduction in the number of Staphylococcus aureus recovered from the ear. Moreover, relative mRNA expression levels of IL-4 and interferon-Ī³ in the skin lesions of mice injected with IL-10 plasmid DNA were also decreased compared with those of control mice. Of note, higher serum IL-10 levels in mice injected with IL-10 plasmid DNA were maintained compared with those in control mice. Taken together, the results indicate that IL-10 plasmid DNA can suppress the development of AD-like skin lesions by suppressing both Th1 and Th2 cell responses. Beneficial effects of IL-10 plasmid DNA may be expected in dogs with AD
Molecular analysis of post-harvest withering in grape by AFLP transcriptional profiling
Post-harvest withering of grape berries is used in the production of dessert and fortified wines to alter must quality characteristics and increase the concentration of simple sugars. The molecular processes that occur during withering are poorly understood, so a detailed transcriptomic analysis of post-harvest grape berries was carried out by AFLP-transcriptional profiling analysis. This will help to elucidate the molecular mechanisms of berry withering and will provide an opportunity to select markers that can be used to follow the drying process and evaluate different drying techniques. AFLP-TP identified 699 withering-specific genes, 167 and 86 of which were unique to off-plant and on-plant withering, respectively. Although similar molecular events were revealed in both withering processes, it was apparent that off-plant withering induced a stronger dehydration stress response resulting in the high level expression of genes involved in stress protection mechanisms, such as dehydrin and osmolite accumulation. Genes involved in hexose metabolism and transport, cell wall composition, and secondary metabolism (particularly the phenolic and terpene compound pathways) were similarly regulated in both processes. This work provides the first comprehensive analysis of the molecular events underpinning post-harvest withering and could help to define markers for different withering processes
Survival of adult neurons lacking cholesterol synthesis in vivo
BACKGROUND: Cholesterol, an essential component of all mammalian plasma membranes, is highly enriched in the brain. Both during development and in the adult, brain cholesterol is derived from local cholesterol synthesis and not taken up from the circulation. However, the contribution of neurons and glial cells to total brain cholesterol metabolism is unknown. RESULTS: Using conditional gene inactivation in the mouse, we disrupted the squalene synthase gene (fdft1), which is critical for cholesterol synthesis, in cerebellar granule cells and some precerebellar nuclei. Mutant mice showed no histological signs of neuronal degeneration, displayed ultrastructurally normal synapses, and exhibited normal motor coordination. This revealed that these adult neurons do not require cell-autonomous cholesterol synthesis for survival or function. CONCLUSION: We conclude that at least some adult neurons no longer require endogenous cholesterol synthesis and can fully meet their cholesterol needs by uptake from their surrounding. Glia are a likely source of cholesterol in the central nervous system
Molecular basis for group-specific activation of the virulence regulator PlcR by PapR heptapeptides
The transcriptional regulator PlcR and its cognate cellācell signalling peptide PapR form a quorum-sensing system that controls the expression of extra-cellular virulence factors in various species of the Bacillus cereus group. PlcR and PapR alleles are clustered into four groups defining four pherotypes. However, the molecular basis for group specificity remains elusive, largely because the biologically relevant PapR form is not known. Here, we show that the in vivo active form of PapR is the C-terminal heptapeptide of the precursor, and not the pentapeptide, as previously suggested. Combining genetic complementation, anisotropy assays and structural analysis we provide a detailed functional and structural explanation for the group specificity of the PlcRāPapR quorum-sensing system. We further show that the C-terminal helix of the PlcR regulatory domain, specifically the 278 residue, in conjunction with the N-terminal residues of the PapR heptapeptide determines this system specificity. Variability in the specificity-encoding regions of plcR and papR genes suggests that selection and evolution of quorum-sensing systems play a major role in adaptation and ecology of Bacilli
Gene expression profiling of meningiomas: current status after a decade of microarray-based transcriptomic studies
Purpose This article provides a review of the transcriptomic expression profiling studies that have been performed on meningiomas so far. We discuss some future prospects and challenges ahead in the field of gene expression profiling. Methods We performed a systematic search in the PubMed and EMBASE databases in May 2010 using the following search terms alone or in combination: āmeningiomaā, āmicroarray analysisā, āoligonucleotide array sequence analysisā, or āgene expression profilingā. Only original research articles in English that had used RNA hybridized to high-resolution microarray chips to generate gene expression profiles were included. Results We identified 13 articles matching the inclusion criteria. All studies had been performed during the last decade. Conclusions The main results of the studies can be grouped in three categories: (1) several groups have identified meningioma-specific genes and genes associated with the three WHO grades, and the main histological subtypes of grade I meningiomas; (2) one publication has shown that the general transcription profile of samples of all WHO grades differs in vivo and in vitro; (3) one report provides evidence that microarray technology can be used in an automated fashion to classify tumors. Due to lack of consensus on how microarray data are presented, possible general trends found across the studies are difficult to extract. This could obstruct the discovery of important genes and pathways universally involved in meningioma biology
- ā¦