Prevalence of multidrug-resistant organisms in migrant children admitted to an Italian cardiac surgery department, 2015-2016.

Screening on hospital admission to identify multidrug-resistant organism (MDRO) colonization is a frequently discussed topic. We report the results of microbiological screening in 141 Italian and 354 migrant children candidates for cardiac surgery conducted in 2015-2016. In all, 25% of Italian children and more than 65.4% of African and Romanian children carried at least one MDRO (meticillin-resistant Staphylococcus aureus; extended-spectrum ß-lactamase enzymes; carbapenemase producers; and vancomycin-resistant enterococci). Based on our findings, we propose that non-geographically limited approaches are needed to improve infection prevention and control.

Validation of plasma microRNAs as biomarkers for myotonic dystrophy type 1.

Non-invasive and simple to measure biomarkers are still an unmet need for myotonic dystrophy type 1 (DM1). Indeed, muscle biopsies can be extremely informative, but their invasive nature limits their application. Extracellular microRNAs are emerging humoral biomarkers and preliminary studies identified a group of miRNAs that are deregulated in the plasma or serum of small groups of DM1 patients. Here we adopted very stringent selection and normalization criteria to validate or disprove these miRNAs in 103 DM1 patients and 111 matched controls. We confirmed that 8 miRNAs out of 12 were significantly deregulated in DM1 patients: miR-1, miR-27b, miR-133a, miR-133b, miR-206, miR-140-3p, miR-454 and miR-574. The levels of these miRNAs, alone or in combination, discriminated DM1 from controls significantly, and correlated with both skeletal muscle strength and creatine kinase values. Interestingly, miR-133b levels were significantly higher in DM1 female patients. Finally, the identified miRNAs were also deregulated in the plasma of a small group (n = 30) of DM2 patients. In conclusion, this study proposes that miRNAs might be useful as DM1 humoral biomarkers.

Tibialis anterior muscle needle biopsy and sensitive biomolecular methods: a useful tool in myotonic dystrophy type 1.

Myotonic dystrophy type 1 (DM1) is a neuromuscular disorder caused by a CTG repeat expansion in 3'UTR of DMPK gene. This mutation causes accumulation of toxic RNA in nuclear foci leading to splicing misregulation of specific genes. In view of future clinical trials with antisense oligonucleotides in DM1 patients, it is important to set up sensitive and minimally-invasive tools to monitor the efficacy of treatments on skeletal muscle. A tibialis anterior (TA) muscle sample of about 60 mg was obtained from 5 DM1 patients and 5 healthy subjects through a needle biopsy. A fragment of about 40 mg was used for histological examination and a fragment of about 20 mg was used for biomolecular analysis. The TA fragments obtained with the minimally-invasive needle biopsy technique is enough to perform all the histopathological and biomolecular evaluations useful to monitor a clinical trial on DM1 patients.

Vitamin D, parathyroid hormone and muscle impairment in myotonic dystrophies.

Parathyroid function in Myotonic Dystrophy (DM) patients has been poorly investigated. Parathyroid and muscle parameters were assessed in 31 male DM1 (44±2 years), 13 male DM2 (56±2 years) and 32 healthy controls. Hyperparathyroidism was diagnosed in 18% of patients without differences between DM types. In all DM patients, hyperparathyroidism was associated with normocalcemia but one with hypercalcemia. DM patients presented significantly higher PTH and lower vitamin D (25OHD) compared with controls, also considering seasonality. Severe vitamin D deficiency (25OHD<10 ng/ml) was diagnosed in 40% and hypovitaminosis D (25OHD<30 ng/ml) occurred in 88% of DM patients. About one-third of DM1 presented hypophosphatemia associated with elevated PTH levels. Serum 25OHD levels negatively correlated with PTH and with body fat mass. Considering DM1 patients, serum PTH levels positively correlated with CTG triplet repeats. Furthermore, PTH levels negatively correlated with total modified Medical Research Council (MRC) and positively with Muscular Impairment Rating Scale (MIRS). By contrast, in DM2 patients muscle assessment did not show any correlation with parathyroid function. In conclusion, we arrived at the following: 1) severe vitamin D deficiency is common in DM patients and it is associated with secondary hyperparathyroidism; 2) primary hyperparathyroidism, though rare, may occur; 3) increased adiposity in DM may be a risk factor for hypovitaminosis D; and 4) high serum PTH levels may indicate a muscle impairment, at least in DM1.

Increased risk for non-autoimmune hypothyroidism in young patients with congenital heart defects.

CONTEXT: Newborns with congenital hypothyroidism (CH) have an increased risk for congenital heart defects (CHD) due to a common embryonic developmental program between thyroid gland and heart and great vessels. OBJECTIVE: Our objective was to investigate the prevalence and origin of thyroid disorders in young patients with CHD. DESIGN AND SETTING: We conducted a prospective observational study between January 2007 and January 2009 in academic Pediatric Cardiosurgery and Endocrinology. PATIENTS: Patients included 324 children (164 males, 160 females, aged 0.2-15.4 yrs) with CHD. INTERVENTION: Subjects underwent hormonal and genetic screening. MAIN OUTCOME MEASURES: Serum TSH and thyroid hormone levels were assessed. RESULTS: Two CHD patients were diagnosed with CH at the neonatal screening (1:162). Mild hypothyroidism (serum TSH > 4.0 µU/ml) was diagnosed and confirmed 6 months later [TSH = 5.4 ± 1.5 µU/ml; free T(4) = 1.3 ± 0.2 ng/dl (normal values 0.8-1.9)] in 37 children (11.5%) who were negative at neonatal screening. Hypothyroidism was not related to type of CHD, whereas TSH levels positively correlated with serum N-terminal pro-type B natriuretic peptide levels. Biochemical and ultrasound findings consistent with thyroid autoimmunity were present in three of 37 hypothyroid children (8.1%). One patient had hemiagenesis (2.7%). Variations in candidate genes were screened in CHD patients. NKX2.5 coding sequence was normal in all samples. A 3-Mb microdeletion in 22q11.2 was detected in three patients (8.3%), whereas only known polymorphisms were identified in TBX1 coding sequence. CONCLUSIONS: CHD patients have an increased risk for both CH (10-fold higher) and acquired mild hypothyroidism (3-fold higher). Unrecognized mild hypothyroidism may negatively affect the outcome of CHD children, suggesting that thyroid function should be repeatedly checked. Thyroid autoimmunity and 22q11.2 microdeletions account for small percentages of these cases, and still unknown mechanisms underline such a strong association.

Analysis of the 206M polymorphic variant of the SLC26A6 gene encoding a Cl- oxalate transporter in patients with primary hyperparathyroidism.

OBJECTIVE: Primary hyperparathyroidism (PHPT) is often complicated by kidney stones. Hypercalciuria and urine oxalate excretion are considered risk factors for urolithiasis in PHPT as well as in idiopathic stone-formers. Recently, the anion-exchanger SLC26A6 has been involved in the oxalate metabolism. DESIGN AND METHODS: We tested the hypothesis that the 206M polymorphic variant of SLC26A6 gene might contribute to the risk of kidney stones in PHPT. DNA samples from 145 PHPT patients and 129 age- and sex-matched healthy subjects were genotyped. RESULTS: The homozygous 206V genotype was the most frequent both in PHPT patients and controls (79.3 and 74.4%), while heterozygosity for the 206M allele was detected in 20.0 and 23.3% respectively. The homozygous 206M genotype was extremely rare, occurring in 0.7 and 2.3% of PHPT and healthy subjects respectively. In the PHPT cohort, the prevalence of urolithiasis did not differ between the V/V and V/M+M/M groups and urine oxalate excretions did not correlate with the genotype. Considering the subset of PHPT stone formers (n=74), calciuria was lower in V/M+M/M patients with respect to V/V stone-formers (4.40+/-1.88 vs 5.92+/-2.62 mg/kg per 24 h; mean+/-s.d., P=0.034). Finally, the SLC26A6 206M alleles were significantly related to the presence of hypertension (73.3 vs 47.8%), showing an OR of 4.8. CONCLUSIONS: Though the SLC26A6 206M polymorphism did not correlate with kidney stone development in PHPT patients, PHPT stone-formers harbouring the M allele had a lower hypercalciuria. This observation and the high prevalence of hypertension associated with the 206M polymorphism need further investigation.

Association of rat8 with Fyn protein kinase via lipid rafts is required for rat mammary cell differentiation in vitro.

We previously identified rat8 in the pathway involved in epithelial cell differentiation that occurs in the rat mammary gland at pregnancy when tubules and alveoli are formed. rat8, which encodes an IFN-inducible membrane protein, is the rat homologue of the mouse gene fragilis. By differential detergent extraction and isopycnic sucrose density gradients, we show that rat8 protein is associated to lipid membrane domains together with Lyn and Fyn, members of the Src tyrosine kinase family. We also show that recruitment of rat8 to lipid membrane domains is a necessary step in mammary epithelial cell differentiation. Immunoprecipitation analysis, performed with an anti-Fyn protein antibody, shows that rat8 was present in the Fyn immunoprecipitate. Antisense oligonucleotides, used to inhibit Fyn protein expression, block mammary cell differentiation. Taken together, these results suggest that the functional interaction, via lipid membrane domains, of rat8 and Fyn proteins is required for mammary cell differentiation. Therefore, rat8, like fragilis, may be involved in developmental decisions and the demarcation of a subset of cells in the mammary gland that cause epithelial cells to develop into a network of tubuloalveolar structures involved in secretion.

Dome formation in cell cultures as expression of an early stage of lactogenic differentiation of the mammary gland.

The study of the development of the mammary gland at the molecular level in the animal is difficult because of the complex tissue organization of the gland. We have previously developed an in vitro system for genetic analysis of mammary cell differentiation, based on the cell line LA7 clonally derived from a rat mammary adenocarcinoma. This cell line, after induction with DMSO, differentiates forming structures called domes. This process is under strict gene regulation, and we have previously identified several of the genes involved. In the present paper, we have defined the meaning of dome formation in relation to mammary development, by showing that treatment of LA7 cells with the lactogenic hormones hydrocortisone and prolactin induces dome formation; in the animal, these hormones precede and accompany milk production. Moreover, dome formation is accompanied by expression within the cells of the milk protein genes WDMN1 and beta-casein, which are differentiation markers for the gland during pregnancy and lactation. We also show that two proteins, highly expressed in the mammary gland during lactation, HSP90-beta and annexin I, are strongly expressed in DMSO-induced LA7 cells. Both proteins are essential in the formation of domes because when their synthesis is blocked by antisense RNA oligonucleotides, dome formation is abolished. Thus our in vitro system is a model for lobulo-alveolar development, and the genes identified in the pathway of dome formation are likely to be involved in the early differentiation steps occurring in the rat mammary gland during pregnancy and lactation.

Proteomic dissection of dome formation in a mammary cell line: role of tropomyosin-5b and maspin.

In this work we extended the study of genes controlling the formation of specific differentiation structures called "domes" formed by the rat mammary adenocarcinoma cell line LA7 under the influence of DMSO. We have reported previously that an interferon-inducible gene, rat-8, and the beta-subunit of the epithelial sodium channel (ENaC) play a fundamental role in this process. Now, we used a proteomic approach to identify proteins differentially expressed either in DMSO-induced LA7 or in 106A10 cells. Two differentially expressed proteins were investigated. The first, tropomyosin-5b, strongly expressed in DMSO-induced LA7 cells, is needed for dome formation because its synthesis inhibition by the antisense RNA technology abolished domes. The second protein, maspin, strongly expressed in the uninduced 106A10 cell line, inhibits dome formation because 106A10 cells, transfected with rat8 cDNA (the function of which is required for the organization of these structures), acquired the ability to develop domes when cultured in presence of an antimaspin antibody. Dome formation in these cultures are accompanied by ENaC beta-subunit expression in the absence of DMSO. Therefore, dome formation requires the expression of tropomyosin-5b, in addition to the ENaC beta-subunit and the rat8 proteins, and is under the negative control of maspin.