Identification of 26 new constitutional RB1 gene mutations in Spanish, Colombian, and Cuban retinoblastoma patients

Constitutional mutations in the RB1 gene predispose to retinoblastoma development. Hence genetic screening of retinoblastoma patients and relatives is important for genetic counseling purposes. In addition, RB1 gene mutation studies may help decipher the molecular mechanisms leading to tumors with different degrees of penetrance or expressivity. In the course of genetically screening of 107 hereditary and non-hereditary retinoblastoma patients (11 familiar bilateral, 4 familiar unilateral, 49 sporadic bilateral and 43 sporadic unilateral) and kindred from Spain, Colombia and Cuba, using direct PCR sequencing, we observed 45 distinct mutations and four RB1 deletions in 53 patients (9 familiar bilateral, 2 familiar unilateral, 31 sporadic bilateral and 11 sporadic unilateral). Most of these mutations (26/45, 57%) have not been reported before. In 32 patients, the predisposing mutations correspond to nonsense (mainly CpG transitions) and small insertions or deletions whose expected outcome is a truncated Rb protein that lacks the functional pockets and tail. Five single aminoacid replacements and seventeen mutations affecting splicing sites were also observed in retinoblastoma patients. Two of these sixteen mutations are of unclear pathogenic nature.     

Molecular and Cellular Mechanisms of Delayed Fracture Healing in Mmp10 (Stromelysin 2) Knockout Mice

The remodeling of the extracellular matrix is a central function in endochondral ossification and bone homeostasis. During secondary fracture healing, vascular invasion and bone growth requires the removal of the cartilage intermediate and the coordinate action of the collagenase matrix metalloproteinase (MMP)-13, produced by hypertrophic chondrocytes, and the gelatinase MMP-9, produced by cells of hematopoietic lineage. Interfering with these MMP activities results in impaired fracture healing characterized by cartilage accumulation and delayed vascularization. MMP-10, Stromelysin 2, a matrix metalloproteinase with high homology to MMP-3 (Stromelysin 1), presents a wide range of putative substrates identified in vitro, but its targets and functions in vivo and especially during fracture healing and bone homeostasis are not well defined. Here, we investigated the role of MMP-10 through bone regeneration in C57BL/6 mice. During secondary fracture healing, MMP-10 is expressed by hematopoietic cells and its maximum expression peak is associated with cartilage resorption at 14 days post fracture (dpf). In accordance with this expression pattern, when Mmp10 is globally silenced, we observed an impaired fracture-healing phenotype at 14 dpf, characterized by delayed cartilage resorption and TRAP-positive cell accumulation. This phenotype can be rescued by a non-competitive transplant of wild-type bone marrow, indicating that MMP-10 functions are required only in cells of hematopoietic linage. In addition, we found that this phenotype is a consequence of reduced gelatinase activity and the lack of proMMP-9 processing in macrophages. Our data provide evidence of the in vivo function of MMP-10 during endochondral ossification and defines the macrophages as the lead cell population in cartilage removal and vascular invasion. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).     

Women Chefs’ Access Barriers to Michelin Stars: A Case-Study Based Approach

The higher the status in the “haute cuisine” field, the fewer women are employed in prestigious positions. Although cooking is considered a feminine competence, it becomes masculine when it is considered a professional job. Therefore, there are recognized gender barriers for women to achieve chef positions in the field. This article discusses the case of six female chefs who were awarded three Michelin stars in 2014 and one with two stars. The goal was to research how these women met the criteria of the Michelin Guide and which were the specific aspects that distinguished them from the rest. Although in their discourse, gender barriers were not highly accentuated, however, passion, the feminine approach to management, and family support were considered mandatory for their success.     

The tumor suppressor SirT2 regulates cell cycle progression and genome stability by modulating the mitotic deposition of H4K20 methylation

The establishment of the epigenetic mark H4K20me1 (monomethylation of H4K20) by PR-Set7 during G₂/M directly impacts S-phase progression and genome stability. However, the mechanisms involved in the regulation of this event are not well understood. Here we show that SirT2 regulates H4K20me1 deposition through the deacetylation of H4K16Ac (acetylation of H4K16) and determines the levels of H4K20me2/3 throughout the cell cycle. SirT2 binds and deacetylates PR-Set7 at K90, modulating its chromatin localization. Consistently, SirT2 depletion significantly reduces PR-Set7 chromatin levels, alters the size and number of PR-Set7 foci, and decreases the overall mitotic deposition of H4K20me1. Upon stress, the interaction between SirT2 and PR-Set7 increases along with the H4K20me1 levels, suggesting a novel mitotic checkpoint mechanism. SirT2 loss in mice induces significant defects associated with defective H4K20me1–3 levels. Accordingly, SirT2-deficient animals exhibit genomic instability and chromosomal aberrations and are prone to tumorigenesis. Our studies suggest that the dynamic cross-talk between the environment and the genome during mitosis determines the fate of the subsequent cell cycle.     

Utility of a commercial immunoblot kit (BAG-Borrelia blot) in the diagnosis of the preliminary stages of Lyme disease

The aim of this study was to evaluate the usefulness of a commercial immunoblot (IgG and IgM BAG-Borrelia blot) in the serologic diagnosis of the early stages of Lyme disease. A total of 42 sera from patients with Lyme disease (24 patients with localized early stage (LES) and 18 patients with disseminated early stage (DES)) and 129 sera from patients with non-Lyme diseases (specificity control sera) were studied. IgG anti-p41 from Borrelia burgdorferi s.l. was present in 95.2% of patients followed by anti-p41/I PBi (16.7%), anti-p100 (9.5%) and anti-OspA (9.5%). IgM anti-p41 was present in 66.7% of patients, p41/iPBi (54.8%) and OspC (33.3%). IgM against p100, OspA and OspC were more frequent in DES patients (16.7%, 27.8% and 44.4%) than in LES patients (0.0%, 4.2% and 25.0%). In 4.8% of the cases no IgG bands were present and in 26.2% no IgM bands were present. With the exception of isolated p41 bands (59.5%), no band pattern exceeded 17%. Using manufacturer's instructions, test sensitivity in diagnosis of the early stage of Lyme disease is 61.9%, specificity 98.4% and positive and negative predictive values 92.8% and 88.8% respectively. Applying the EUCALB 5, 6 or 7 rules sensitivity increased to 73.8% although specificity decreased to 89.9%. Of the 129 specific control sera, 41.8% presented IgG anti-p41 and 10.8% IgM anti-p41. Patients with non-Lyme diseases that presented more IgG and IgM bands were those patients with syphilis (88.2%), patients with anti-HIV antibodies (57.8%) and patients with anti-nuclear antibodies (ANA) (52.3%).     

Can lithium salts prevent depressive episodes in the real world?

To critically examine the effectiveness of lithium in preventing depressive symptoms (mixed and depressive episodes) in real life settings, taking into account adherence to drug treatment and its implications for the clinical costs of the disease. Overall, 72 patients with bipolar disorder initially treated with lithium carbonate were included and followed-up for 10 years. Patients were assessed every 8 weeks for morbidity and alcohol/drug consumption. Patients with good adherence to lithium had fewer episodes with depressive features than poor adherers (B?=?2.405, p?=?0.046) and also fewer manic and hypomanic episodes (B?=?2.572; p?<?0.001), after controlling for confounders. Time to relapse into a depressive or mixed episode and into a manic or hypomanic episode was shorter in patients with poor adherence. The costs of the 1.95?±?2.38 (mean?±?standard deviation) admissions of adherent patients through the 10 years of follow-up were €10,349, while the costs of the 6.25?±?4.92 admissions of non-adherent patients were €44,547. In clinical practice settings, long-term lithium salts seem to have a preventive effect on depressive symptoms.     

Effectiveness and safety of direct-acting antivirals in hepatitis C infected patients with mental disorders: Results in real clinical practice

The aim of this study is to analyze the effectiveness and safety of direct-acting antivirals (DAAs) in psychiatric patients with chronic hepatitis C (CHC). Secondary objectives included adherence and drug-drug interaction (DDIs) evaluations. Prospective observational comparative study carried out during 3 years. Psychiatric patients were included and mental illness classified by a psychiatric team based on clinical records. Main effectiveness and safety variables were sustained virologic response (SVR) at posttreatment week 12 (SVR12) and rate of on-treatment serious drug-related adverse events (AEs), respectively. A total of 242 psychiatric and 900 nonpsychiatric patients were included. SVR12 by intention-to-treat (ITT) analysis of psychiatric vs nonpsychiatric patients was 92.6% (95% confidence interval [CI], 89.1-96.1) vs 96.2% (95% CI, 94.9-97.5) (P = .02). SVR12 by modified-ITT analysis was 97.8% (95% CI, 95.0-99.3) vs 98.4% (95% CI, 97.5-99.3) (P = .74). 92.2% of psychiatric patients with mental disorders secondary to multiple drug use (MDSDU) and 93.0% of psychiatric patients without MDSDU vs 96.2% of nonpsychiatric patients reached SVR12 (P = .05 and P = .20, respectively). The percentage of adherent patients to DAAs did not show differences between cohorts (P = .08). 30.2% of psychiatric patients and 27.6% of nonpsychiatric patients presented clinically relevant DDIs (P = .47). 1.7% vs 0.8% of psychiatric vs nonpsychiatric patients developed serious AEs (P = .39); no serious psychiatric AEs were present. DAAs have shown a slightly lower effectiveness in psychiatric patients with CHC, as a result of loss of follow up, which justifies the need for integrated and multidisciplinary health care teams. DAAs safety, adherence, and DDIs, however, are similar to that of nonpsychiatric patients.