Prenatal diagnosis in Li-Fraumeni syndrome

PURPOSE: The hallmark of Li-Fraumeni syndrome (LFS), a familial cancer syndrome, is constitutional TP53 mutation. The authors addressed the complex question of predictive prenatal genetic testing for cancer risk associated with inheritance of TP53 mutation. METHODS: A classic LFS family including the proband (a 20-month-old boy with rhabdomyosarcoma), his 36-year-old father with osteosarcoma, and his 40-year-old paternal aunt with bilateral breast cancer were identified as carriers of a TP53 germline mutation, a novel 1 base pair deletion in exon 5. A few years later, the mother became pregnant twice, and the parents requested prenatal diagnosis on each occasion. Genetic counseling, psychological evaluation, and support were provided by a multidisciplinary team including a pediatric oncologist, a geneticist, a psychosocial worker, a prenatal care provider, and an ethical representative. After providing overall information on LFS, including the high risk of developing secondary multiple neoplasms in LFS survivors, the committee approved prenatal diagnosis at the request of the family. RESULTS: In the two pregnancies, the two fetuses were found to be carriers of the same mutation. Nine years from diagnosis of the first tumor, the proband, and a month later his father, developed second tumors, multifocal osteosarcoma and leiomyosarcoma, respectively. CONCLUSIONS: Children with primary tumors belonging to LFS should be considered for screening for germline mutations and genetic counseling by a multidisciplinary team. Whether family members are found to be positive or negative as carriers, such measures may provide, by reducing uncertainty, psychological benefit to high-risk families.     

A PLEA FOR INCIDENTAL APPENDECTOMY IN PEDIATRIC PATIENTS WITH MALIGNANCY

The evaluation of right lower quadrant (RLQ) abdominal pain in pediatric patients with malignancy can be difficult. However, since the mortality rate from peritoneal infections in these patients is very high, the differential diagnosis of RLQ peritoneal irritation, mainly of acute appendicitis (AA) versus neutropenic enterocolitis (NE), is crucial. Three cases of pediatric patients with malignancy demonstrating these difficulties are represented to enlighten this problem. The first patient died of multiorgan failure after operation for perforated appendicitis without generalized peritonitis. The second had a severe life-threatening postoperative complication because of delayed diagnosis of acute appendicitis. The third patient with malignant pelvic spread, underwent an unnecessary abdominal exploration for suspected AA. In all these cases and probably in many others, the clinical outcome could have been different if a previous incidental appendectomy had been performed during the primary abdominal operation. Incidental appendectomy in oncologic patients is recommended to facilitate the differential diagnosis of RLQ pain and to exclude the diagnosis of AA.     

Hyperglycemia potentiates H(2)O(2) production in adipocytes and enhances insulin signal transduction: potential role for oxidative inhibition of thiol-sensitive protein-tyrosine phosphatases

Insulin signal transduction in adipocytes is accompanied by a burst of cellular hydrogen peroxide (H(2)O(2)) that facilitates insulin signaling by inhibiting thiol-dependent protein-tyrosine phosphatases (PTPs) that are negative regulators of insulin action. As hyperglycemia is associated with increased cellular reactive oxygen species, we postulated that high glucose conditions might potentiate the H(2)O(2) generated by insulin and modulate insulin-stimulated protein phosphorylation. Basal H(2)O(2) generation was increased threefold in differentiated 3T3-L1 adipocytes by growth in 25 mM glucose versus 5 mM glucose. High glucose increased the sensitivity of the insulin-stimulated H(2)O(2) signal to lower concentrations of insulin. Basal endogenous total PTP activity and the activity of PTP1B, a PTP implicated in the negative regulation of insulin signaling, were reduced in high glucose conditions, and their further reduction by insulin stimulation was more enhanced in high versus low glucose medium. Phosphorylation of the insulin receptor, IRS-1, and Akt in response to insulin was also significantly enhanced in high glucose conditions, especially at submaximal insulin concentrations. In primary rat adipocytes, high glucose increased insulin-stimulated H(2)O(2) production and potentiated the oxidative inhibition of total PTP and PTP1B activity; however, insulin signaling was not enhanced in the primary cells in high glucose apparently due to cross-regulation of insulin-stimulated protein phosphorylation by activation of protein kinase C (PKC). These studies indicate that high glucose can enhance insulin stimulated H(2)O(2) generation and augment oxidative PTP inhibition in cultured and primary adipocytes, but the overall balance of insulin signal transduction is determined by additional signal effects in high glucose, including the activation of PKC.     

Orienting response elicitation by personally significant information under subliminal stimulus presentation: Demonstration using the Concealed Information Test

Considerable evidence suggests that subliminal information can trigger cognitive and neural processes. Here, we examined whether elicitation of orienting response by personally significant (PS) verbal information requires conscious awareness of the input. Subjects were exposed to the Concealed Information Test (CIT), in which autonomic responses for autobiographical items are typically larger than for control items. These items were presented subliminally using two different masking protocols: single or multiple presentation of the masked item. An objective test was used to verify unawareness to the stimuli. As predicted, PS items elicited significantly stronger skin conductance responses than the control items in both exposure conditions. The results extend previous findings showing that autonomic responses can be elicited following subliminal exposure to aversive information, and also may have implications on the applied usage of the CIT.     

β-Cell neogenesis: experimental considerations in adult stem cell differentiation

The contribution of stem cells derived from adult tissues to the recovery of pancreatic islets from chemical injury is controversial. Analysis of nonhematopoietic differentiation of bone marrow-derived cells has yielded positive and negative results under different experimental conditions. Using the smallest subset of bone marrow cells lacking immuno-hematopoietic lineage markers, we have detected incorporation and conversion into insulin-producing cells. Donor cells identified by genomic markers silence green fluorescent protein (GFP) expression as a feature of differentiation, in parallel to expressing PDX-1 and proinsulin. Here we elaborate potential experimental difficulties that might result in false-negative results. The use of GFP as a reporter protein is suboptimal for differentiation experiments: (a) the bone marrow of GFP donors partially expresses the reporter protein, (b) differentiating bone marrow cells silence GFP expression, and (c) the endocrine pancreas is constitutively negative for GFP. In addition, design of the experiments, data analysis, and interpretation encounter numerous objective and subjective difficulties. Rigorous evaluation under optimized experimental conditions confirms the capacity of adult bone marrow-derived stem cells to adopt endocrine developmental traits, and demonstrates that GFP downregulation and silencing is a feature of differentiation.     

The Sheba Medical Center healthcare workers' children's school: can we open schools safely?

ObjectiveThe role of school closure in mitigating coronavirus disease 2019 (COVID-19) transmission has been questioned. In our medical centre, during a 9-week national lockdown, an alternative school was opened for health-care workers' (HCW) children with a small number of children per class and strict symptom surveillance. After lockdown was lifted we screened children and their parents for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serology.MethodsWe conducted a cross-sectional study of HCW parents and their children after one teacher contracted COVID-19 following exposure at home and 53 children were exposed, isolated and tested by RT-PCR. We compared families with children attending the alternative school with families whose children who remained at home during the 9-week lockdown. Epidemiological and medical data were collected using a short questionnaire; nasopharyngeal and oropharyngeal swabs were obtained and tested for SARS-CoV-2 by RT-PCR, and blood was collected for SARS-CoV-2 IgA and IgG titres.ResultsA total of 435 children attended the Sheba alternative school. Among the 53 children exposed to the infected teacher, none tested positive by RT-PCR. Of these, 18 children–parent pairs were tested for serology and all were negative. A total of 106/435 (24%) children and their 78 parents were recruited for the cross-sectional study; 70 attended the Sheba school and 36 did not. Approximately 16% of children in either group reported symptoms (11/70 in the school group and 6/36 in the ‘stay home’ group), but SARS-CoV-2 was not detected by PCR in any, and previous exposure, as determined by serological tests, was low and not significantly different between the groups.ConclusionIn an alternative school for children of HCWs, active during COVID-19 national outbreak, we found no evidence of increased infection compared with children that stayed home.     

Immunomodulation for treatment and prevention of atherosclerosis

In recent years, it has become clear that the immune system has a major role in atherosclerosis development and progression. More specifically, atherosclerosis fulfills all four criteria to define a condition as being an autoimmune in nature. This association also suggests that modification of the immune response in atherosclerosis could affect this process. In this review, we summarize different aspects of immunomodulation in atherosclerosis. These include immunosuppression, active immunization, induction of tolerance, administration of intravenous immunoglobulin, gene therapy, cytokine network manipulation and statins.     

Angiotensin 1–7, but not the thrombin-cleaved osteopontin C-terminal fragment,attenuates osteopontin-mediated macrophage-induced endothelial-cell inflammation

Objective and design

Evaluating the pro-/anti-inflammatory activity of the C-terminal cleavage product of osteopontin in comparison to angiotensin 1–7.

Material and subjects

Human coronary endothelial cells (hcEC) treated with conditioned media from human U937 macrophages.

Treatment

Macrophages were (pre)treated with C-terminal, full-length or N-terminal osteopontin (OPN-C, OPN-FL, OPN-N, respectively), angiotensin II, angiotensin 1–7 or TNF-α. OPN-C modulatory capacity was compared to that of Ang1–7 in inhibiting subsequent Ag II, OPN-FL or OPN-N-induced macrophage-mediated endothelial inflammation.

Methods

Protein expression of NFκB, IκB, vCAM-1 and iCAM-1 was assessed using western blot. Promotor activation by NFκB was also assessed by dual-luciferase reporter assay.

Results

Conditioned media of macrophages treated with OPN-C induced hcECs’ NfκB activation to a lower degree than OPN-FL or OPN-N. Priming of macrophages with angiotensin 1–7 attenuated the endothelial pro-inflammatory effect induced by subsequent exposure of the macrophages to angiotensin II, OPN-FL or OPN-N. This was evidenced by both NfκB activation and vCAM and iCAM expression. In contrast, priming macrophages with OPN-C did not significantly attenuate the subsequent response to the pro-inflammatory cytokines.

Conclusions

OPN-C induces lower macrophage-induced endothelial inflammation compared to OPN-FL or OPN-N, but unlike angiotensin 1–7, fails to prevent endothelial inflammation induced by subsequent pro-inflammatory macrophage stimulation.