Life-threatening complications of streptococcal sepsis: a PICU contemporary series.

BACKGROUND: Life-threatening streptococcal sepsis nowadays represents an uncommon event in previously healthy infants and children. Critically ill patients suffering from severe streptococcal sepsis complications may present with pre-antibiotic era clinical pictures and require a timely clinical approach to achieve restitutio ad integrum. RESULTS: We report a series of four patient groups affected by an uncommon life-threatening streptococcal sepsis, each of them exhibiting some distinct features. Streptococcus Agalactiae sepsis was associated with cerebral thrombotic/ischaemic lesions, whereas severe cardiogenic shock was prominent in the Streptococcus Viridans group; Streptococcus Faecalis and ß-hemolytic group A Streptococcus patients mostly reported lung complications. CONCLUSIONS: Previous antibiotic treatments should not delay aggressive treatment in the intensive care setting. Early diagnostic suspicion, as well as appropriate and aggressive treatment provided within an intensive care setting are crucial for the clinical outcome.

Circadian disruption promotes tumor-immune microenvironment remodeling favoring tumor cell proliferation.

Circadian disruption negatively affects physiology, posing a global health threat that manifests in proliferative, metabolic, and immune diseases, among others. Because outputs of the circadian clock regulate daily fluctuations in the immune response, we determined whether circadian disruption results in tumor-associated immune cell remodeling, facilitating tumor growth. Our findings show that tumor growth rate increased and latency decreased under circadian disruption conditions compared to normal light-dark (LD) schedules in a murine melanoma model. Circadian disruption induced the loss or inversion of daily patterns of M1 (proinflammatory) and M2 (anti-inflammatory) macrophages and cytokine levels in spleen and tumor tissues. Circadian disruption also induced (i) deregulation of rhythmic expression of clock genes and (ii) of cyclin genes in the liver, (iii) increased CcnA2 levels in the tumor, and (iv) dampened expression of the cell cycle inhibitor p21WAF/CIP1 , all of which contribute to a proliferative phenotype.

Chemical hazard for dental hygienists: a systematic review.

OBJECTIVE: Dental hygienists (DHs) are professionals responsible for oral health. They deal with professional oral hygiene, counselling, and screening patients for oral health, as well as preventing and treating oral diseases. However, DH responsibilities and duties may vary worldwide, characterising changeable occupational exposure scenarios and making it difficult to achieve a suitable evaluation of workplace risks, particularly regarding chemical exposure. Therefore, the aim of the present work was to provide a comprehensive overview on the current knowledge on DH chemical risks. MATERIALS AND METHODS: According to the PRISMA guidelines, a systematic review of PubMed, Scopus, and Isi Web of Knowledge databases was performed to retrieve all articles assessing DH occupational chemical exposures. RESULTS: Fragmented data are currently available on DH chemical risk, due to the limited number of studies on the topic and few DHs enrolled, as well as their frequent assimilation to other oral healthcare professionals. The majority of the retrieved investigations focused on possible hypersensitivity reactions caused by natural rubber latex exposure, but not on potential risks derived from other currently employed substances or innovative wide-spreading compounds. CONCLUSIONS: Future research should be focused on assessing DH chemical risks according to a more comprehensive and toxicologically standardised approach to achieve an appropriate awareness among the DH workforce concerning the possibility for hazardous exposure and adverse health effects. Overall, this may lead to the adoption/implementation of adequate preventive measures to protect the health and safety of these oral healthcare professionals.

'Frequently recurring' nocturnal polyuria is predictive of response to desmopressin in monosymptomatic nocturnal enuresis in childhood.

INTRODUCTION: The nocturnal polyuria is considered a significant predictive value for response to desmopressin. The cutoff value useful to define nocturnal polyuria is still a matter of debate. Moreover, it is current notion that maximal voided volume (MVV) could be used as a predictor for desmopressin response. OBJECTIVE: The objective of this study was to assess the impact of different definitions of nocturnal polyuria (and of its frequency) and MVV in predicting the response to desmopressin. STUDY DESIGN: A total of 103 patients with frequent monosymptomatic nocturnal enuresis (≥4 wet nights/week) were enrolled. A bladder diary over a 4-day period was collected. The MVV was defined as the highest micturition volume detected at bladder diary. Nocturnal diuresis was measured in 5 wet nights. Then, patients were administered with 120 mcg of sublingual desmopressin. After 2 months, if there was no complete response, the dose was increased to 240 mcg. Nocturnal polyuria was defined as follows: 1.Definition 1: nocturnal urine production >130% of the expected bladder capacity (EBC). 2. Definition 2: >100% EBC. 3. Definition 3: > 20×(age + 9) mL. The primary outcome was 'response to desmopressin' after 3 months of treatment. RESULTS: Fifty-three patients responded to desmopressin. Comparing the responses to desmopressin on the basis of the three definitions of nocturnal polyuria, no significant difference was found. There was no cutoff value of nocturnal polyuria expressed as %EBC useful in providing a significant receiver-operating characteristic (ROC) curve. The area under the ROC curve for MVV expressed as %EBC was 0.67 (95% confidence interval [CI], 0.54-0.80; p = 0.01). A MVV >103.1% of EBC had 78.8% (95% CI, 61.1-91.0) sensitivity and 47.5% (95% CI, 31.5-63.9) specificity for predicting response to desmopressin. Among the patients with nocturnal polyuria according to definition 1, a higher percentage of subjects with nocturnal polyuria in 4 out of 5 or 5 out of 5 nights responded to desmopressin, compared with other patients. Patients presenting with nocturnal polyuria according to definition 3 in 5 out of 5 nights showed a 100% of response to desmopressin. At multivariate analysis, the only significant odds ratio (OR) to respond to desmopressin was that of patients with nocturnal polyuria according to definition 1 in >3 nights (OR = 7.1, 95% CI, 1.3-40.3). DISCUSSION AND CONCLUSIONS: The presence or absence of nocturnal polyuria-according to all three definitions-in at least one night was not effective in predicting the response to desmopressin. Predictors of desmopressin response were nocturnal polyuria in >3 out of 5 wet nights according to definition 1 and in 5 out of 5 wet nights according to definition 3.

Randomised clinical trial: a Lactobacillus GG and micronutrient-containing mixture is effective in reducing nosocomial infections in children, vs. placebo.

BACKGROUND: Nosocomial infections are a major public health issue and preventative strategies using probiotics and micronutrients are being evaluated. AIM: To investigate the efficacy of a mixture of Lactobacillus GG and micronutrients in preventing nosocomial infections in children. METHODS: A randomised, double-blind, placebo-controlled trial was conducted in hospitalised children. Children (6 months to 5 years of age) received Lactobacillus GG (6 × 10(9) CFU/day) together with vitamins B and C and zinc or placebo, for 15 days, starting on the first day of hospitalisation. The incidence of gastrointestinal and respiratory nosocomial infections after discharge was determined by follow-up telephone call at 7 days. After 3 months, another telephone call estimated the incidence of further infections during follow-up. RESULTS: Ninety children completed the follow-up. Of 19/90 children with a nosocomial infection (20%), 4/45 children (9%) were in the treatment group and 15/45 (33%) in the placebo group (P = 0.016). Specifically, 2/45 (4%) children in the treatment group vs. 11/45 (24%) children in the placebo group (P = 0.007) presented with diarrhoea. The duration of hospitalisation was significantly shorter in the treatment group (3.9 days ± 1.7 vs. 4.9 ± 1.2; P = 0.003). At the follow-up, a total of 11/45 (24.4%) children in the treatment group had at least one episode of infection compared to 22/45 (48.9%) in the placebo group (P = 0.016). CONCLUSION: A mixture containing Lactobacillus GG and micronutrients may reduce the incidence of nosocomial infections, supporting the hypothesis that this may represent a valid strategy to prevent nosocomial infections.

PATZ1 interacts with p53 and regulates expression of p53-target genes enhancing apoptosis or cell survival based on the cellular context.

PATZ1 is a transcriptional factor functioning either as an activator or a repressor of gene transcription depending upon the cellular context. It appears to have a dual oncogenic/anti-oncogenic activity. Indeed, it is overexpressed in colon carcinomas, and its silencing inhibits colon cancer cell proliferation or increases sensitivity to apoptotic stimuli of glioma cells, suggesting an oncogenic role. Conversely, the development of B-cell lymphomas, sarcomas, hepatocellular carcinomas and lung adenomas in Patz1-knockout (ko) mice supports its tumour suppressor function. PATZ1 role in mouse lymphomagenesis is mainly because of the involvement of PATZ1 in BCL6-negative autoregulation. However, this does not exclude that PATZ1 may be involved in tumorigenesis by other mechanisms. Here, we report that PATZ1 interacts with the tumour suppressor p53 and binds p53-dependent gene promoters, including those of BAX, CDKN1A and MDM2. Knockdown of PATZ1 in HEK293 cells reduces promoter activity of these genes and inhibits their expression, suggesting a role of PATZ in enhancing p53 transcriptional activity. Consistently, Patz1-ko mouse embryonic fibroblasts (MEFs) show decreased expression of Bax, Cdkn1a and Mdm2 compared with wild-type (wt) MEFs. Moreover, Patz1-ko MEFs show a decreased percentage of apoptotic cells, either spontaneous or induced by treatment with 5-fluorouracil (5FU), compared with wt controls, suggesting a pro-apoptotic role for PATZ1 in these cells. However, PATZ1 binds p53-target genes also independently from p53, exerting, in the absence of p53, an opposite function on their expression. Indeed, knockdown of PATZ1 in p53-null osteosarcoma cells upregulates BAX expression and decreases survival of 5FU-treated cells, then suggesting an anti-apoptotic role of PATZ1 in p53-null cancer cells. Therefore, these data support a PATZ1 tumour-suppressive function based on its ability to enhance p53-dependent transcription and apoptosis. Conversely, its opposite and anti-apoptotic role in p53-null cancer cells provides the perspective of PATZ1 silencing as a possible adjuvant in the treatment of p53-null cancer.

Development of JAK2V617F-positive polycythemia vera after chemotherapy-induced remission of primary central nervous system diffuse large B cell non-Hodgkin's lymphoma: a case report and review of the literature.

The coexistence or the development of Philadelphia chromosome-negative myeloproliferative neoplasms after a lymphoproliferative disease in the same patient is an extremely rare event. We report the case of a 72-year-old man who developed JAK2V617F polycythemia vera 3 years after the diagnosis and treatment of primary diffuse large B cell non-Hodgkin's lymphoma of the central nervous system. We also review the literature regarding the pathogenesis underlying the association of myeloproliferative and lymphoproliferative chronic disorders.

OxLDL- and HSP-60 antigen-specific CD8(+) T lymphocytes are detectable in the peripheral blood of patients suffering from coronary artery disease.

Inflammatory and immunologic mechanisms are important for the initiation and the progression of atherosclerotic lesions. OxLDL and HSP-60 antigens are involved in the pathogenesis of atherosclerotic disease by triggering immune cells within the plaques. Through the MHC pentamer assays, we investigated the presence of OxLDL- and HSP-60-specific CD8(+) T lymphocytes in twenty HLA-A2-positive patients suffering from coronary artery disease (10 NSTEMI and 10 stable angina). Similarly, 10 age- and sex-matched healthy subjects were enrolled as controls. Biological samples were collected within 6 h of admission to hospital, at 30 days and at 180 days. OxLDL- and HSP-60-specific CD8(+) T lymphocytes were never detectable in the peripheral blood from all the healthy controls. On the contrary, at each scheduled time point, both of these specific cells could be detected in peripheral blood from all enrolled patients. More in detail, the flow cytometric analysis of MHC-1 pentamer OxLDL-specific CD8(+) T lymphocytes revealed a sharp and significant increase at the hospital admission, within 6 h from the chest pain onset, followed by an evident decline to lower levels at 30 days and at 180 days from the enrollment in the study. On the contrary, although MHC-1 pentamer HSP-60 CD8(+) T lymphocytes were detectable in enrolled patients, almost no variance could be detectable during the follow-up scheduled evaluations. On the whole, this finding indicates that HSP-60- and OxLDL-specific CD8(+) T lymphocytes could play a role in the maintenance or worsening of the atherosclerotic coronary disease.

Downregulation of HMGA-targeting microRNAs has a critical role in human pituitary tumorigenesis.

Previous studies have demonstrated that high mobility group A proteins have a critical role on the onset of human pituitary adenomas. Indeed, both high mobility group A (HMGA) genes are overexpressed in pituitary adenomas, and consistently transgenic mice overexpressing either the Hmga1 or the Hmga2 gene develop mixed growth hormone/prolactin (GH-PRL)-secreting pituitary adenomas. Trisomy of chromosome 12, where HMGA2 is located, and/or amplification of the HMGA2 gene locus account for the HMGA2 overexpression in most human prolactinomas. Conversely, HMGA1 overexpression is not associated to any rearrangement or amplification of the HMGA1 locus. We have first identified micro RNAs (miRNAs) able to target both HMGA1 and HMGA2 messenger RNAs. Then, all of these miRNAs have been found downregulated in pituitary adenomas of different histotypes, compared with normal pituitary. Interestingly, their downregulation was also observed in nonfunctioning pituitary adenomas where HMGA2 overexpression is not associated to any alteration of the HMGA2 locus. Functional studies show that all these HMGA-targeting miRNAs inhibit the proliferation of the rat pituitary adenoma cell line GH3. Therefore, these results indicate that the downregulation of the miRNAs able to target the HMGA genes could contribute to increase HMGA protein levels in human pituitary adenomas, and then to pituitary tumorigenesis.

HMGA proteins promote ATM expression and enhance cancer cell resistance to genotoxic agents.

DNA-damaging therapies represent a keystone in cancer treatment. Unfortunately, many tumors often relapse because of a group of cancer cells, which are resistant to conventional therapies. High-mobility group A (HMGA) proteins has a key role in cell transformation, and their overexpression is a common feature of human malignant neoplasias, representing a poor prognostic index often correlated to anti-cancer drug resistance. Our previous results demonstrated that HMGA1 is a substrate of ataxia-telangiectasia mutated (ATM), the main cellular sensor of genotoxic stress. Here we also report thatHMGA2, the other member of the HMGA family, is a novel substrate of ATM. Interestingly, we found that HMGA proteins positively regulate ATM gene expression. Moreover, induction of ATM kinase activity by DNA-damaging agents enhances HMGA-dependent transcriptional activation of ATM promoter, suggesting that ATM expression is modulated by a DNA-damage- and HMGA-dependent positive feedback loop. Finally, inhibition of HMGA expression in mouse embryonic fibroblasts and in cancer cells strongly reduces ATM protein levels, impairing the cellular DNA-damage response and enhancing the sensitivity to DNA-damaging agents. These findings indicate this novel HMGA-ATM pathway as a new potential target to improve the effectiveness of conventional anti-neoplastic treatments on the genotoxic-drug resistant cancer cells.

Regulation of microRNA expression by HMGA1 proteins.

The High Mobility Group proteins HMGA1 are nuclear architectural factors that play a critical role in a wide range of biological processes. Since recent studies have identified the microRNAs (miRNAs) as important regulators of gene expression, modulating critical cellular functions such as proliferation, apoptosis and differentiation, the aim of our work was to identify the miRNAs that are physiologically regulated by HMGA1 proteins. To this purpose, we have analysed the miRNA expression profile of mouse embryonic fibroblasts (MEFs) carrying two, one or no Hmga1 functional alleles using a microarray (miRNA microarray). By this approach, we found a miRNA expression profile that differentiates Hmga1-null MEFs from the wild-type ones. In particular, a significant decrease in miR-196a-2, miR-101b, miR-331 and miR-29a was detected in homozygous Hmga1-knockout MEFs in comparison with wild-type cells. Consistently, these miRNAs are downregulated in most of the analysed tissues of Hmga1-null mice in comparison with the wild-type mice. ChIP assay shows that HMGA1 is able to bind regions upstream of these miRNAs. Moreover, we identified the HMGA2 gene product as a putative target of miR-196a-2, suggesting that HMGA1 proteins are able to downregulate the expression of the other member of the HMGA family through the regulation of the miR-196a-2 expression. Finally, ATXN1 and STC1 gene products have been identified as targets of miR-101b. Therefore, it is reasonable to hypothesize that HMGA1 proteins are involved in several functions by regulating miRNA expression.

HAND1 gene expression is negatively regulated by the High Mobility Group A1 proteins and is drastically reduced in human thyroid carcinomas.

HMGA1 proteins exert their major physiological function during embryonic development and play a critical role in neoplastic transformation. Here, we show that Hand1 gene, which codes for a transcription factor crucial for differentiation of trophoblast giant cells and heart development, is upregulated in hmga1 minus embryonic stem cells. We demonstrate that HMGA1 proteins bind directly to Hand1 promoter both in vitro and in vivo and inhibit Hand1 promoter activity. We have also investigated HAND1 expression in human thyroid carcinoma cell lines and tissues, in which HMGA proteins are overexpressed, with respect to normal thyroid; an inverse correlation between HMGA1 and HAND1 expression was found in all thyroid tumor histotypes. A correlation between HAND1 gene repression and promoter hypermethylation was found in anaplastic carcinomas but not in other thyroid tumor histotypes. Therefore, we can hypothesize that HMGA1 overexpression plays a key role on HAND1 silencing in differentiated thyroid carcinomas and that promoter hypermethylation occurs in later stages of thyroid tumor progression. Finally, the restoration of the HAND1 gene expression reduces the clonogenic ability of two human thyroid carcinoma-derived cell lines, suggesting that HAND1 downregulation may have a role in the process of thyroid carcinogenesis.

PATZ1 gene has a critical role in the spermatogenesis and testicular tumours.

PATZ1 is a recently discovered zinc finger protein that, due to the presence of the POZ domain, acts as a transcriptional repressor affecting the basal activity of different promoters. To gain insights into its biological role, we generated mice lacking the PATZ1 gene. Male PATZ1(-/-) mice were unfertile, suggesting a crucial role of this gene in spermatogenesis. Consistently, most of adult testes from these mice showed only few spermatocytes, associated with increased apoptosis, and complete absence of spermatids and spermatozoa, with the subsequent loss of tubular structure. The analysis of PATZ1 expression, by northern blot, western blot and immunohistochemistry, revealed its presence in Sertoli cells and, among the germ cells, exclusively in the spermatogonia. Since PATZ1 has been indicated as a potential tumour suppressor gene, we also looked at its expression in tumours deriving from testicular germ cells (TGCTs). Although expression of PATZ1 protein was increased in these tumours, it was delocalized in the cytoplasm, suggesting an impaired function. These results indicate that PATZ1 plays a crucial role in normal male gametogenesis and that its up-regulation and mis-localization could be associated to the development of TGCTs.

Detection of high-mobility group proteins A1 and A2 represents a valid diagnostic marker in post-pubertal testicular germ cell tumours.

The high-mobility group A (HMGA) non-histone chromosomal proteins HMGA1 and HMGA2 are architectural factors. They are abundantly expressed during embryogenesis and in most malignant neoplasias, whereas their expression is low or absent in normal adult tissues. Their over-expression is known to have a causal role in cellular neoplastic transformation. Previous studies from our group have shown that their expression is restricted to specific germinal cells. In this study we have evaluated, by immunohistochemistry, the expression of HMGA1 and HMGA2 in a series of post-pubertal testicular tumours of different histological types, including 30 seminomas, 15 teratomas, 15 embryonal carcinomas and 10 mixed germinal tumours with a prominent yolk sac tumour component. HMGA1 protein expression was detected in all seminomas and embryonal carcinomas analysed, but not in teratomas or yolk sac carcinomas. Conversely, HMGA2 was present only in embryonal carcinomas and yolk sac carcinomas, but not in seminomas or teratomas. The immunohistochemical data were further confirmed by Western blot and, at the mRNA level, by RT-PCR analyses. These findings indicate that HMGA1 and HMGA2 are differently expressed with respect to the state of differentiation of testicular germ cell tumours (TGCTs), with over-expression of both proteins in pluripotential embryonal carcinoma cells and loss of expression of HMGA1 in yolk sac tumours and of both proteins in the mature adult tissue of teratoma areas. Therefore, the different profiles of HMGA1 and HMGA2 protein expression could represent a valuable diagnostic tool in some cases in which the histological differential diagnosis is problematic.

B-RAF mutations are a rare event in pituitary adenomas.

Pituitary tumors are a relatively common neoplasia whose pathogenesis is still largely unknown. Recent studies have revealed frequent activating mutations of the gene for B-RAF, an effector of Ras protein in the mitogen-activated protein kinase pathway, in several malignancies, including melanoma, thyroid, colorectal and ovarian cancer. However, analyses of B-RAF mutations in pituitary tumors have not been reported so far. Therefore, in the present study we have investigated the presence of the B-RAF mutations, by polymerase chain reaction (PCR) amplification of the hot spot exons 11 and 15, followed by direct sequencing, in 50 human pituitary adenomas, including 25 NFPA and 25 secreting adenomas (10 GH, 5 PRL, 6 LH and/or FSH, 4 GH/PRL). We found only one V600E mutation in a NFPA sample, suggesting that B-RAF mutations are a rare event in pituitary tumorigenesis.

High mobility group I (Y) proteins bind HIPK2, a serine-threonine kinase protein which inhibits cell growth.

The HMGI proteins (HMGI, HMGY and HMGI-C) have an important role in the chromatin organization and interact with different transcriptional factors. The HMGI genes are expressed at very low levels in normal adult tissues, whereas they are very abundant during embryonic development and in several experimental and human tumours. In order to isolate proteins interacting with the HMGI(Y) proteins, a yeast two-hybrid screening was performed using the HMGI(Y) protein as bait. This analysis led to the isolation of homeodomain-interacting protein kinase-2 (HIPK2), a serine/threonine nuclear kinase. HIPK2 co-immunoprecipitates with the HMGI(Y) protein in 293T cells. The interaction between HIPK2 and HMGI(Y) occurs through the PEST domain of HIPK2 and it is direct because in vitro translated HIPK2 binds HMGI(Y). We also show that HIPK2 is able to phosphorylate the HMGI(Y) protein by an in vitro kinase assay. In order to understand a possible role of HIPK2 gene in cell growth we performed a colony assay which showed an impressive HIPK2 inhibitory effect on normal thyroid cells. Flow cytometric analysis would indicate the block of cell growth at the G2/M phase of the cell cycle. Since normal thyroid cells do not express detectable HMGI(Y) protein levels, we assume that the HIPK2 inhibitory effect is independent from the interaction with the HMGI(Y) protein.

RNF4 is a growth inhibitor expressed in germ cells but not in human testicular tumors.

The RING-finger protein RNF4 modulates both steroid-receptor-dependent and basal transcription and interacts with a variety of nuclear proteins involved in cell growth control. RNF4 is expressed at very high levels in testis and at much lower levels in several other tissues. We show that in germ cells RNF4 expression is strongly modulated during progression of spermatogonia to spermatids, with a peak in spermatocytes. Analysis of human testicular germ cell tumors shows that RNF4 is not expressed in all tumors analyzed including seminomas, the highly malignant embryonal carcinomas, yolk sac, and mixed germ cell tumors. We also show that the ectopically expressed RNF4 gene inhibits cell proliferation of both somatic and germ cell tumor-derived cells. Mutation of critical cysteine residues in the RING finger domain abolished the RNF4 growth inhibition activity. Our results suggest that the lack of RNF4 expression may play a role in the progression of testicular tumors.

Role of the high mobility group A proteins in human lipomas.

The HMGA family is comprised of four proteins: HMGA1a, HMGA1b, HMGA1c and HMGA2. The first three proteins are products of the same gene, HMGA1, generated through an alternative splicing mechanism. The HMGA proteins are involved in the regulation of chromatin structure and HMGA DNA-binding sites have been identified in functional regions of many gene promoters. Rearrangements of the HMGA2 gene have been frequently detected in human benign tumors of mesenchymal origin including lipomas. 12q13-15 chromosomal translocations involving the HMGA2 gene locus, account for these rearrangements. The HMGA proteins have three AT-hook domains and an acidic C-terminal tail. The HMGA2 modifications consist in the loss of the C-terminal tail and fusion with ectopic sequences. A pivotal role of the HMGA2 rearrangements in the process of lipomagenesis is suggested by experiments showing that transgenic mice carrying a truncated HMGA2 gene showed a giant phenotype together with abdominal/pelvic lipomatosis. As HMGA2 null mice showed a great reduction in fat tissue, a positive role of the HMGA2 gene in adipocytic cell proliferation is proposed. More recently, similar alterations of the HMGA1 gene have been described. As the block of the HMGA1 protein synthesis induces an increase in growth rate of the pre-adipocytic cell line 3T3-L1, we suggest a negative role of the HMGA1 proteins in adipocytic cell growth and, therefore, we propose that adipocytic cell growth derives from the balance of the HMGA1 and HMGA2 protein functions.