103 research outputs found
Risky Mortgages in a DSGE Model
This paper develops a DSGE model with housing, risky mortgages and endogenous default. Housing investment is subject to idiosyncratic risk and some mortgages are defaulted in equilibrium. An unanticipated increase in the standard deviation of housing investment produces a credit crunch where delinquencies and mortgage interest rates increase, lending is curtailed, and aggregate demand for non-durable goods falls. The economy experiences a recession as a consequence of the credit crunch. The paper compares economies that differ only in the riskiness of housing investment. Economies with lower risk are characterized by lower steady-state mortgage default rates and higher loan-to-value and leverage ratios. The macroeconomic effects of an unanticipated increase in housing investment risk are amplified in high-leverage economies. Monetary policy plays an important role in the transmission of housing investment risk, as inertial interest rate rules generate deeper output contractions.Housing, Mortgage default, Mortgage Risk
Mortgage Amortization and Amplification
Mortgages characterized by negative or low early amortization schedules amplify the macroeconomic effects of a housing risk shock. We analyze the role of mortgage amortization in a two-sector DSGE model with housing risk and endogenous default. Mortgage loan contracts extend to two periods and have adjustable rates. The fraction of principal to be repaid in the first period can vary. As the fraction of principal to be paid in the first period falls, steady-state mortgages and leverage increase and the impact of a housing risk shock on consumption and output is amplified. Borrowers prefer negative amortization. If free to choose the amortization schedule, borrowers would repay most of the principal in the last period of the contract. Low early repayments of principal allow borrowers to hold on to their housing stock and postpone default to the second period having incurred small sunk costs.Housing, Mortgage default, Mortgage risk
Mortgage Amortization and Amplification
Mortgages characterized by negative or low early amortization schedules amplify the macroeconomic effects of a housing risk shock. We analyze the role of mortgage amortization in a two-sector DSGE model with housing risk and endogenous default. Mortgage loan contracts extend to two periods and have adjustable rates. The fraction of principal to be repaid in the first period can vary. As the fraction of principal to be paid in the first period falls, steady-state mortgages and leverage increase and the impact of a housing risk shock on consumption and output is amplified. Borrowers prefer negative amortization. If free to choose the amortization schedule, borrowers would repay most of the principal in the last period of the contract. Low early repayments of principal allow borrowers to hold on to their housing stock and postpone default to the second period having incurred small sunk costs
Differential Control of Notch1 Gene Transcription by Klf4 and Sp3 Transcription Factors in Normal versus Cancer-Derived Keratinocytes
In specific cell types like keratinocytes, Notch signaling plays an important pro-differentiation and tumor suppressing function, with down-modulation of the Notch1 gene being associated with cancer development. Besides being controlled by p53, little else is known on regulation of Notch1 gene expression in this context. We report here that transcription of this gene is driven by a TATA-less âsharp peakâ promoter and that the minimal functional region of this promoter, which extends from the â342 bp position to the initiation codon, is differentially active in normal versus cancer cells. This GC rich region lacks p53 binding sites, but binds Klf4 and Sp3. This finding is likely to be of biological significance, as Klf4 and, to a lesser extent, Sp3 are up-regulated in a number of cancer cells where Notch1 expression is down-modulated, and Klf4 over-expression in normal cells is sufficient to down-modulate Notch1 gene transcription. The combined knock-down of Klf4 and Sp3 was necessary for the reverse effect of increasing Notch1 transcription, consistent with the two factors exerting an overlapping repressor function through their binding to the Notch1 promoter
Effects of loading methods on rabbit welfare and meat quality
The effects of different loading methods on the welfare, carcass characteristics and meat quality traits of hybrid commercial rabbits were investigated. 384 male rabbits, 82 days old, were transported from the farm to the slaughterhouse. At the farm, 192 rabbits were loaded onto the truck smoothly (S) and 192 rabbits were loaded roughly (R). The S loading method consisted of carefully placing each rabbit into the transport crates. In the R method, the loading was hurriedly and carelessly executed by the transport operator, throwing each animal into the crates fixed on the truck.
Live weight before and after transport as well as slaughter data were recorded for each rabbit, and a subset of 80 carcasses were evaluated for meat quality. Blood samples from 80 rabbits were analysed for haematological and biochemical parameters. A significant neutrophilia (P < 0.001), lymphocytopaenia (P < 0.001) and an increase in serum aspartate aminotransferase (AST) (P < 0.01), alanine aminotransferase (ALT) (P < 0.001) and creatine kinase (CK) activities (P < 0.001) were recorded in all rabbits after transport, independent of the loading method. A twofold increase in serum corticosterone concentration (6.23 vs. 14.88 ng/mL; P = 0.001) was observed in all rabbits following transport. Results suggest that the stress parameters analysed were more influenced by transport and handling itself rather than by the different loading methods. The results showed that there was no adverse effect of loading method on carcass traits. Furthermore, the stress condition evidenced by haematological and biochemical parameters prior to slaughter did not affect meat quality
Potential Mechanisms of Ovarian Protection with Gonadotropin-Releasing Hormone Agonist in Breast Cancer Patients: A Review
The use of chemotherapy in premenopausal cancer patients may lead to chemotherapy-induced premature ovarian failure. Pharmacological temporary ovarian suppression obtained with the gonadotropin-releasing hormone agonist (GnRHa) administered concomitantly with chemotherapy has been investigated as a technique capable to reduce the gonadotoxicity, reducing the risk of developing premature menopause. In recent years, important evidence has become available on the efficacy and safety of this strategy that should now be considered a standard option for ovarian function preservation in premenopausal breast cancer patients. However, in women interested in fertility preservation, this is not an alternative to cryopreservation strategies, which remains the first option to be proposed. The purpose of this review is to summarize the mechanisms of GnRHa in the preservation of fertility in premenopausal cancer patient candidates to receive chemotherapy, highlighting the areas of doubt that require further investigation
Management of young women with early breast cancer
Breast cancer is still the most frequent cancer diagnosed in women aged 6440 years and the primary cause of death in this age group. The management of these patients needs a dedicated approach involving a multidisciplinary team that takes into account their treatment and survivorship issues. The present review aims to provide a perspective on the many challenges associated with treatment of young women with early breast cancer. We will focus on the standard (neo)adjuvant treatment, highlighting the paucity of age-specific results about the available genomic signatures, the groundbreaking landscape of adjuvant endocrine therapy and the relevant issue of the fertility preservation
Gonadotropin Releasing Hormone Agonists Have an Anti-apoptotic Effect on Cumulus Cells
Background: Ovaries are sensitive to chemotherapy, which may lead to early depletion of primordial follicle reserve. One strategy for gonadal function preservation is temporary ovarian suppression with Gonadotropin Releasing Hormone agonists (GnRHa) during chemotherapy. To date, GnRHa protective mechanism of action remains not fully elucidated. Methods: We collected 260 immature cumulus cell-oocyte complexes (COC) from 111 women < 38 years old, with a normal ovarian reserve. The COC were randomly assigned to the following groups: (a) control; culture with the addition of (b) GnRHa; (c) cyclophosphamide; (d) cyclophosphamide plus GnRHa. After in vitro treatments, RNA and proteins were extracted from oocytes and cumulus cells (CC), separately. Potential effects of drugs were evaluated on GnRH receptors, apoptosis pathways, ceramide pathway, and glutathione synthesis by quantitative PCR and, whenever possible, by Western blot. Results: Cyclophosphamide triggered activation of the extrinsic pathway of apoptosis mediated by BAX in CC. The co-administration of GnRHa inhibited the apoptosis pathway in CC. According to our model, the GnRHa does not directly act on oocytes, which do not express GnRH receptors. Moreover, glutathione synthesis was decreased after GnRHa treatment both in CC and oocytes. Conclusion: Our data suggest that the protective mechanisms induced by GnRHa is mediated by an anti-apoptotic effect on CC
Will PAXgene substitute formalin? A morphological and molecular comparative study using a new fixative system
Formalin fixation and paraffin embedding present the standard procedures for conserving clinical tissues for histological analysis. However, molecular analysis is impaired by the cross linking properties of formalin. The PAXgene tissue system (PreAnalytix, Switzerland) is a new formalin-free tissue collection device. AIMS: In this study we aimed to evaluate this new tissue preservation technique in comparison with formalin fixation and fresh frozen tissue samples. METHODS: 12 melanoma biopsy samples were divided and fixed simultaneously with formalin, PAXgene or fresh frozen in liquid nitrogen and analysed with regard to morphology, immunohistochemistry, DNA and RNA content and quality. Markers of melanocytic differentiation and tumour cell proliferation were used. RESULTS: Morphology was well preserved in PAXPE samples. However, 5 out of 11 immunohistochemical markers showed significantly lower overall staining and staining intensity with PAXPE tissues in comparison with formalin-fixed, paraffin-embedded (FFPE). Increasing membrane permeability through adding a detergent did proportionally increase staining intensity in PAXPE samples. Amplification of different mRNA amplicons showed a direct relationship with the size of the amplicon with greater template integrity observed in PAXPE samples. Sequencing and mutational analysis of DNA samples were comparable for all the different fixation methods, while the level of DNA fragmentation seemed to be lower in PAXPE compared with FFPE tissues. CONCLUSIONS: The switch from formalin to PAXgene fixation would require a re-evaluation of immunohistochemical markers and staining procedures originally developed for FFPE tissues. Our data demonstrate that PAXPE fixation offers some advantages concerning molecular analysis. However, these advantages would not justify substituting formalin fixation in any routine pathology laboratory
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