A note on preconditioning weighted linear least squares, with consequences for weakly-constrained variational data assimilation

The effect of preconditioning linear weighted least-squares using an approximation of the model matrix is analyzed, showing the interplay of the eigenstructures of both the model and weighting matrices. A small example is given illustrating the resulting potential inefficiency of such preconditioners. Consequences of these results in the context of the weakly-constrained 4D-Var data assimilation problem are finally discussed.Comment: 10 pages, 2 figure

Identification of Novel Wsf1 Mutations in a Sicilian Child with Wolfram Syndrome

Wolfram Syndrome (WS) is a rare hereditary disease with autosomal recessive inheritance with incomplete penetrance. It is characterized by diabetes mellitus associated with progressive optic atrophy. The diagnosis is essentially clinical and mutation analysis is used to confirm the diagnosis. In the present study we describe the clinical and molecular features of a diabetic child carrying two novel WFS1 mutations. The Sicilian proband and his non-affected family were studied. Ophthalmologic examination included: visual acuity determination and funduscopy, optical coherent tomography, retinal fluorangiography, perimetry and electroretinogram. Molecular methods: automatic sequencing of PCR amplified WFS1 gene fragments and qRT-PCR analysis of WFS1 transcripts. 3 WSF1 mutations have been identified in the proband. One allele carries 2 paternally inherited mutations (c.1332 C>G and c.1631C>G) in exon-8, never annotated before, in heterozygosis with one “de novo” classic mutation (c.505 G>A) in exon-5. In addition, we report an unexpected molecular feature: higher WFS1 mRNA levels in the proband compared to the father

NANOG plays a hierarchical role in the transcription network regulating the pluripotency and plasticity of adipose tissue-derived stem cells

The stromal vascular cell fraction (SVF) of visceral and subcutaneous adipose tissue (VAT and SAT) has increasingly come into focus in stem cell research, since these compartments represent a rich source of multipotent adipose-derived stem cells (ASCs). ASCs exhibit a self-renewal potential and differentiation capacity. Our aim was to study the different expression of the embryonic stem cell markers NANOG (homeobox protein NANOG), SOX2 (SRY (sex determining region Y)-box 2) and OCT4 (octamer-binding transcription factor 4) and to evaluate if there exists a hierarchal role in this network in ASCs derived from both SAT and VAT. ASCs were isolated from SAT and VAT biopsies of 72 consenting patients (23 men, 47 women; age 45 ± 10; BMI between 25 ± 5 and 30 ± 5 range) undergoing elective open-abdominal surgery. Sphere-forming capability was evaluated by plating cells in low adhesion plastic. Stem cell markers CD90, CD105, CD29, CD31, CD45 and CD146 were analyzed by flow cytometry, and the stem cell transcription factors NANOG, SOX2 and OCT4 were detected by immunoblotting and real-time PCR. NANOG, SOX2 and OCT4 interplay was explored by gene silencing. ASCs from VAT and SAT confirmed their mesenchymal stem cell (MSC) phenotype expressing the specific MSC markers CD90, CD105, NANOG, SOX2 and OCT4. NANOG silencing induced a significant OCT4 (70 ± 0.05%) and SOX2 (75 ± 0.03%) downregulation, whereas SOX2 silencing did not affect NANOG gene expression. Adipose tissue is an important source of MSC, and siRNA experiments endorse a hierarchical role of NANOG in the complex transcription network that regulates pluripotency

Gender differences in chronic liver diseases in two cohorts of 2001 and 2014 in Italy

Background: Gender differences in chronic liver disease (CLD) have been partially investigated. To extend the present knowledge, we evaluated 12,263 patients with CLD enrolled in two national surveys (9997 in 2001 and 2557 in 2014). Methods: The two surveys prospectively recruited patients aged â¥Â 18 referring to Italian liver units throughout the country using a similar clinical approach and analytical methods. Results: The overall male to female ratio (M/F) was 1.4 (7138/5124). Compared with females, males were significantly more likely to be younger (52.9 vs. 58.7 yrs.), with HBV infection alone (13.2% vs. 9.2%) and with alcoholic liver disease alone (11.4% vs. 6.9%), but less likely to show HCV infection alone (48.0% vs. 67.9%). A male preponderance was observed in HBV-related cases (1.99) and in alcoholic-related cases (2.3), a preponderance observed both in the 2001 and in 2014 cases. In HCV-related cases, however, females predominated in 2001 (M/F 0.9) and males in 2014 (M/F 1.5).The rate of cirrhosis in alcohol-related etiology was close to 36% in both genders, a finding much higher than that observed for both sexes in HBV and HCV etiologies.Both males and females enrolled in 2014 were older (p < 0.001) and with a higher rate of cirrhosis and/or HCC (p < 0.001) than those investigated in 2001. There was a remarkable increase over time in the proportion of male abstainers (36.7% in 2001 and 64.3% in 2014). Conclusion: This study highlights important inter- and intra-gender differences in the characteristics and etiological factors of patients with CLD in Italy

Bioengineering thymus organoids to restore thymic function and induce donor-specific immune tolerance to allografts

One of the major obstacles in organ transplantation is to establish immune tolerance of allografts. Although immunosuppressive drugs can prevent graft rejection to a certain degree, their efficacies are limited, transient, and associated with severe side effects. Induction of thymic central tolerance to allografts remains challenging, largely because of the difficulty of maintaining donor thymic epithelial cells in vitro to allow successful bioengineering. Here, the authors show that three-dimensional scaffolds generated from decellularized mouse thymus can support thymic epithelial cell survival in culture and maintain their unique molecular properties. When transplanted into athymic nude mice, the bioengineered thymus organoids effectively promoted homing of lymphocyte progenitors and supported thymopoiesis. Nude mice transplanted with thymus organoids promptly rejected skin allografts and were able to mount antigen-specific humoral responses against ovalbumin on immunization. Notably, tolerance to skin allografts was achieved by transplanting thymus organoids constructed with either thymic epithelial cells coexpressing both syngeneic and allogenic major histocompatibility complexes, or mixtures of donor and recipient thymic epithelial cells. Our results demonstrate the technical feasibility of restoring thymic function with bioengineered thymus organoids and highlight the clinical implications of this thymus reconstruction technique in organ transplantation and regenerative medicine

In Vitro Identification and Characterization of CD133pos Cancer Stem-Like Cells in Anaplastic Thyroid Carcinoma Cell Lines

Background: Recent publications suggest that neoplastic initiation and growth are dependent on a small subset of cells, termed cancer stem cells (CSCs). Anaplastic Thyroid Carcinoma (ATC) is a very aggressive solid tumor with poor prognosis, characterized by high dedifferentiation. The existence of CSCs might account for the heterogeneity of ATC lesions. CD133 has been identified as a stem cell marker for normal and cancerous tissues, although its biological function remains unknown. Methodology/Principal Findings: ATC cell lines ARO, KAT-4, KAT-18 and FRO were analyzed for CD133 expression. Flow cytometry showed CD133pos cells only in ARO and KAT-4 (6469% and 57612%, respectively). These data were confirmed by qRT-PCR and immunocytochemistry. ARO and KAT-4 were also positive for fetal marker oncofetal fibronectin and negative for thyrocyte-specific differentiating markers thyroglobulin, thyroperoxidase and sodium/iodide symporter. Sorted ARO/ CD133pos cells exhibited higher proliferation, self-renewal, colony-forming ability in comparison with ARO/CD133neg. Furthermore, ARO/CD133pos showed levels of thyroid transcription factor TTF-1 similar to the fetal thyroid cell line TAD-2, while the expression in ARO/CD133neg was negligible. The expression of the stem cell marker OCT-4 detected by RT-PCR and flow cytometry was markedly higher in ARO/CD133pos in comparison to ARO/CD133neg cells. The stem cell markers c- KIT and THY-1 were negative. Sensitivity to chemotherapy agents was investigated, showing remarkable resistance to chemotherapy-induced apoptosis in ARO/CD133pos when compared with ARO/CD133neg cells. Conclusions/Significance: We describe CD133pos cells in ATC cell lines. ARO/CD133pos cells exhibit stem cell-like features - such as high proliferation, self-renewal ability, expression of OCT-4 - and are characterized by higher resistance to chemotherapy. The simultaneous positivity for thyroid specific factor TTF-1 and onfFN suggest they might represent putative thyroid cancer stem-like cells. Our in vitro findings might provide new insights for novel therapeutic approaches

In Vitro Phenotypic, Genomic and Proteomic Characterization of a Cytokine-Resistant Murine β-TC3 Cell Line

Type 1 diabetes mellitus (T1DM) is caused by the selective destruction of insulin-producing β-cells. This process is mediated by cells of the immune system through release of nitric oxide, free radicals and pro-inflammatory cytokines, which induce a complex network of intracellular signalling cascades, eventually affecting the expression of genes involved in β-cell survival

Geographical pattern of chronic liver diseases in Italy: Results from two pooled national surveys

Background: The information on the geographical characteristics of chronic liver diseases (CLD) in Italy is out-dated. Aim: To provide up-dated information on the geographical pattern of patients with CLD born in Italy. Methods: Patients with CLD were enrolled in two national surveys performed in 2001 and 2014, which prospectively recruited subjects aged ≥18 years referring to Italian liver units located throughout the country that apply a similar clinical approach and analytical methods. Results: The total number of patients enrolled was 11,676. Alcohol-related CLD was more frequently observed in northern/central areas (25.0% vs. 20.7%, p <.001), while HBV-related (15.4% vs. 13.3%, p =.02) and HCV-related (71.2% vs. 67.1%, p <.001) CLD prevailed in southern areas/main islands (Sicily and Sardinia). These differences were stable over time. Liver cirrhosis without HCC was diagnosed more frequently in southern area/islands than in northern/central areas (23.7% vs. 18.8%, p <.01). Moreover, an increased proportion over time of patients with cirrhosis without HCC was observed both in northern/central areas (17.3% vs. 27.4%, p <.01) and in southern area/islands (22.6% vs. 27.9%, p <.01). Conclusions: These up-dated findings show different geographical patterns of CLD in Italy, reflecting different behavioural habits and socio-economic conditions across the country. They may be useful to apply more adequate preventive measures and to allocate economic resources