Oncogene-induced reactive oxygen species fuel hyperproliferation and DNA damage response activation

Oncogene-induced reactive oxygen species (ROS) have been proposed to be signaling molecules that mediate proliferative cues. However, ROS may also cause DNA damage and proliferative arrest. How these apparently opposite roles can be reconciled, especially in the context of oncogene-induced cellular senescence, which is associated both with aberrant mitogenic signaling and DNA damage response (DDR)-mediated arrest, is unclear. Here, we show that ROS are indeed mitogenic signaling molecules that fuel oncogene-driven aberrant cell proliferation. However, by their very same ability to mediate cell hyperproliferation, ROS eventually cause DDR activation. We also show that oncogenic Ras-induced ROS are produced in a Rac1 and NADPH oxidase (Nox4)-dependent manner. In addition, we show that Ras-induced ROS can be detected and modulated in a living transparent animal: the zebrafish. Finally, in cancer we show that Nox4 is increased in both human tumors and a mouse model of pancreatic cancer and specific Nox4 small-molecule inhibitors act synergistically with existing chemotherapic agents.

Oncogene-induced reactive oxygen species fuel hyperproliferation and DNA damage response activation

Oncogene-induced reactive oxygen species (ROS) have been proposed to be signaling molecules that mediate proliferative cues. However, ROS may also cause DNA damage and proliferative arrest. How these apparently opposite roles can be reconciled, especially in the context of oncogene-induced cellular senescence, which is associated both with aberrant mitogenic signaling and DNA damage response (DDR)-mediated arrest, is unclear. Here, we show that ROS are indeed mitogenic signaling molecules that fuel oncogene-driven aberrant cell proliferation. However, by their very same ability to mediate cell hyperproliferation, ROS eventually cause DDR activation. We also show that oncogenic Ras-induced ROS are produced in a Rac1 and NADPH oxidase (Nox4)-dependent manner. In addition, we show that Ras-induced ROS can be detected and modulated in a living transparent animal: the zebrafish. Finally, in cancer we show that Nox4 is increased in both human tumors and a mouse model of pancreatic cancer and specific Nox4 small-molecule inhibitors act synergistically with existing chemotherapic agents.

Lies tell the truth about cognitive dysfunction in essential tremor: an experimental deception study with the guilty knowledge task

BACKGROUND

Research conducted in the past decade challenges the traditional view that essential tremor (ET) is characterised exclusively by movement disorder, and increasingly shows that these patients have deficits in cognitive and behavioural functioning. The available evidence suggests that this impairment might arise from dysfunction in either the fronto-subcortical or cortico-cerebellar circuits. Although abnormalities in the fronto-subcortical circuits could imply difficulty in lying, no study has investigated deception in patients with ET.

AIMS

To examine the cognitive functions regulating deception in patients with ET, we used a computerised task, the Guilty Knowledge Task (GKT). We also tested a group of patients with Parkinson's disease (PD), a disease associated with a known difficulty in lie production, and a group of healthy subjects (HS).

RESULTS

In the GKT for deception, patients with ET responded less accurately than HS (p=0.014) but similarly to patients with PD (p=0.955). No differences between groups were found in truthful responses (p=0.488).

CONCLUSIONS

Besides confirming impaired deception in patients with PD, our results show a lie production deficit in patients with ET also. These findings suggest that difficulty in lying is an aspecific cognitive feature in movement disorders characterised by fronto-subcortical circuit dysfunction, such as PD and ET. Current knowledge along with our new findings in patients with ET--possibly arising from individually unrecognised extremely mild, cognitive difficulties--should help in designing specific rehabilitative programmes to improve cognitive and behavioural disturbances in patients.

Use of Topical or Systemic Steroids in Children with Upper Respiratory Tract Infection

Steroids have long been used to improve a number of clinical conditions because of their role in reducing inflammatory responses, but their use has always been limited because of their possible long-term side effects. The aim of this review is to establish whether steroids can have a positive effect on the outcome of some pediatric upper respiratory tract infections. We used PubMed to select all of the studies on topical or systemic steroids, and their therapeutic use in children with rhinosinusitis (RS), acute otitis media (AOM), otitis media with effusion (OME), acute pharyngitis (AP), or periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA), published over the last 15 years. Although a generally significant improvement in signs and symptoms has been observed with the use of intranasal steroids in children with RS, it is not clear which molecule should be recommended, how long treatment should be continued, or whether the benefits are limited to allergic children. No high-quality studies on the use of topical or systemic steroids in AOM have been carried out, and the results of studies of OME are controversial. The potential positive effects of steroids in children with AP are too slight to justify their use, and their possible adverse effects (particularly in the case of repeated administration) have not been clearly evaluated. Oral corticosteroids seem to be effective in resolving the symptoms of PFAPA, although they do not prevent future fever cycles. These findings show that further randomised and controlled studies are required in order to approach upper respiratory tract infections correctly and avoid the risks associated with frequent steroid use.

High-flow nasal cannula: transient fashion or new method of non-invasive ventilatory assistance?

Respiratory failure in the premature infants remains a difficult challenge. An alternative to the use of nasal continuous positive airway pressure (NCPAP) as a non-invasive modality to support respiratory distress in premature infants has been the recent introduction of high flow nasal cannula (HFNC) devices in many neonatal units. There has been increased use of HFNC presumably because of anecdotal reports and experience that it is easy to use, and well tolerated by the infants, while experiencing decreased nasal septumerosion. The paucity of evidence regarding its efficacy and safety, would support a caution approach to the use of HFNC. Particular concern has focused on the imprecise regulation and generation of pressure that may occur at higher flows especially in the smallest of infants.

A trans-specific polymorphism in ZC3HAV1 is maintained by long-standing balancing selection and may confer susceptibility to multiple sclerosis

The human ZC3HAV1 gene encodes an antiviral protein. The longest splicing isoform of ZC3HAV1 contains a C-terminal PARP-like domain, which has evolved under positive selection in primates. We analyzed the evolutionary history of this same domain in humans and in Pan troglodytes. We identified two variants that segregate in both humans and chimpanzees; one of them (rs3735007) does not occur at a hypermutable site and accounts for a nonsynonymous substitution (Thr851Ile). The probability that the two trans-specific polymorphisms have occurred independently in the two lineages was estimated to be low (P = 0.0054), suggesting that at least one of them has arisen before speciation and has been maintained by selection. Population genetic analyses in humans indicated that the region surrounding the shared variants displays strong evidences of long-standing balancing selection. Selection signatures were also observed in a chimpanzee population sample. Inspection of 1000 Genomes data confirmed these findings but indicated that search for selection signatures using low-coverage whole-genome data may need masking of repetitive sequences. A case–control study of more than 1,000 individuals from mainland Italy indicated that the Thr851Ile SNP is significantly associated with susceptibility to multiple sclerosis (MS) (odds ratio [OR] = 1.47, 95% confidence intervals [CI]: 1.08–1.99, P = 0.011). This finding was confirmed in a larger sample of 4,416 Sardinians cases/controls (OR = 1.18, 95% CI: 1.037–1.344, P = 0.011), but not in a population from Belgium. We provide one of the first instances of human/chimpanzee trans-specific coding variant located outside the major histocompatibility complex region. The selective pressure is likely to be virus driven; in modern populations, this variant associates with susceptibility to MS, possibly via the interaction with environmental factors.

Pregnancy and neonatal respiratory outcome

Preterm labor is the final common pathway of different complications of pregnancy and despite substantial progress in antenatal care, preterm birth remains a major health issue across the globe. Preterm deliveries in the larger group of spontaneous preterm labor or preterm prelabor rupture of membranes (PPROM) are often associated with intrauterine chorioamnionitis. Current evidence underlines the role of "inflammatory" and "placental dysfunction" disorders in pregnancy on prematurity-associated morbidity, particularly respiratory outcome. (www.actabiomedica.it).

Delayed meconium passage in very low birth weight infants

BACKGROUND

Delayed meconium passage, typical of premature newborns, is a predisposing condition for bowel perforation with a significant risk of morbidity and mortality.

AIM OF THE STUDY

A retrospective study was undertaken to verify the entity of the disease, assess the average time to meconium passage in a neonatal population of very low birth weight (VLBW) infants, and identify associated risk factors.

METHODS

The time of first stool passage was studied in 110 VLBW infants (weighing less than 1500 g at birth). Their perinatal features, clinical course, and treatment were reviewed and studied retrospectively.

RESULTS

Delayed meconium passage was recorded in 81% of this group. Patent ductus arteriosus, mechanical ventilation and uteroplacental insufficiency were significantly associated with delayed passage. An inverse relationship between gestational age, birth weight and meconium passage was found. Bowel perforation occurred in 4.5% of this neonatal population with a mortality of 50%.

CONCLUSIONS

In very low birth weight infants delay in the passage of the first stool is common. Perforation in these patients may represent a fatal event, and procedures such as daily rectal enemas, which can prevent this complication, must be applied.

Terminally differentiated astrocytes lack DNA damage response signaling and are radioresistant but retain DNA repair proficiency

The impact and consequences of damage generation into genomic DNA, especially in the form of DNA double-strand breaks, and of the DNA-damage response (DDR) pathways that are promptly activated, have been elucidated in great detail. Most of this research, however, has been performed on proliferating, often cancerous, cell lines. In a mammalian body, the majority of cells are terminally differentiated (TD), and derives from a small pool of self-renewing somatic stem cells. Here, we comparatively studied DDR signaling and radiosensitivity in neural stem cells (NSC) and their TD-descendants, astrocytes - the predominant cells in the mammalian brain. Astrocytes have important roles in brain physiology, development and plasticity. We discovered that NSC activate canonical DDR upon exposure to ionizing radiation. Strikingly, astrocytes proved radioresistant, lacked functional DDR signaling, with key DDR genes such as ATM being repressed at the transcriptional level. Nevertheless, astrocytes retain the expression of non-homologous end-joining (NHEJ) genes and indeed they are DNA repair proficient. Unlike in NSC, in astrocytes DNA-PK seems to be the PI3K-like protein kinase responsible for γH2AX signal generation upon DNA damage. We also demonstrate the lack of functional DDR signaling activation in vivo in astrocytes of irradiated adult mouse brains, although adjacent neurons activate the DDR.

Right colon laparoscopic resection with three-trocar access and associated gynecological procedures in patients with colorectal cancer and ovarian metastases

BACKGROUND

Right laparoscopic colectomy was introduced to colorectal surgery later than the left colon procedure. Three-trocar laparoscopy has already been used successfully in the treatment of gynecological cancers. In the present study, we aimed to analyze the feasibility of performing an associated gynecological procedure following abdominal laparoscopic exploration and to evaluate the suitability of laparoscopic right colectomy for treating elderly patients.

METHODS

We conducted a review of prospectively collected data on 100 consecutive patients who were treated with right laparoscopic colectomy using three trocars from January 2005 to April 2010. We recorded the patients' age (<70 or > 70 years), ASA status, body mass index (BMI), pain on postoperative days 1 and 2 (POD 1, 2), nodes retrieved, laparotomic conversion, mean operative time, time to intestinal recovery, and length of postoperative stay.

RESULTS

All subjects were treated for cancer. Conversion to the laparotomic procedure was performed in 13/100, with no difference in terms of age. Operative time was longer for laparotomic conversion (p <0.05), with a longer postoperative stay. Elderly patients had higher ASA scores (p < 0.005); age did not influence the conversion rate or BMI status. Pain on POD 1 and 2 differed between the laparotomic and laparoscopic groups (p <0.0001). Associated procedures were performed in five subjects (3 oophorectomy and 2 cholecystectomy).

CONCLUSIONS

Laparoscopy using the three-trocar technique is a safe procedure for treating colon cancer, including in elderly patients, and enables associated gynecological laparoscopic procedures to be performed.

Anorectal malformations and neurospinal dysraphism: is this association a major risk for continence?

BACKGROUND/PURPOSE

Anorectal malformations (ARM) are a spectrum of defects ranging from the very minor ones, with an excellent functional prognosis, to those that are more complex, often associated with other anomalies, difficult to manage and with a poor functional outcome. A significant number of these children suffer from fecal and urinary incontinence despite major advances in the management of ARM patients have significantly improved the quality of life. The role of sacrovertebral anomalies/dysraphism (SD) and neurospinal cord anomalies/dysraphism (ND) associated with ARM on the continence of these patients is still controversial. The authors made a review of their experience in a period of 5 years, focusing on the role of neurospinal cord anomalies in patients with ARM.

MATERIALS

At colorectal clinic of our department of pediatric surgery 215 patients who underwent a procedure of posterior sagittal anorectoplasty for ARM are followed-up in a multidisciplinary clinic. Among them 60 patients with either SD or ND were documented. In 37 patients the anomaly involved the spinal cord (ND). 12 of these 37 patients underwent neurosurgical treatment and 25 were managed conservatively. Data collected from their follow-up were analyzed and compared, focusing on their bowel and urinary continence.

RESULTS

All 37 patients acquired regular bowel movements with an appropriate bowel management according to Peña's protocols. Urinary incontinence required clean intermittent catheterization in four cases. None of the patients who did not receive neurosurgical treatment developed acute complications due to the progression of the neurospinal anomaly, like acute urinary retention, orthopedic and motility problems or acute hydrocephalus. From literature review we were unable to find good evidence that the presence of ND worsens the functional prognosis of patients with ARM. We were also unable to find convincing evidence to support the practice of prophylactic neurosurgical procedures.

CONCLUSIONS

The present study supports the theory that for ARM patients the prognosis in terms of continence depends mainly on the type of malformation and is not complicated by the association with ND. In our series neurosurgical treatments did not have any effect in improving the continence of ARM patients and a conservative management of ND did not expose the patients to the sequelae of progressive deterioration, reported elsewhere, requiring rescue neurosurgery. We believe that the correct practice of pediatric surgeons following-up ARM patients is a protocol which includes appropriate investigations to detect the presence of a SD or ND and, once these entities are detected, it is mandatory to manage the patient with a multidisciplinary team, where a conservative non-operative management is initially justified and advocated in the absence of neurosensorymotor symptoms.

Long-term balancing selection maintains trans-specific polymorphisms in the human TRIM5 gene

The human TRIM5 genes encodes a retroviral restriction factor (TRIM5α). Evolutionary analyses of this gene in mammals have revealed a complex and multifaceted scenario, suggesting that TRIM5 has been the target of exceptionally strong selective pressures, possibly exerted by recurrent waves of retroviral infections. TRIM5 displays inter-individual expression variability in humans and high levels of TRIM5 mRNA have been associated with a reduced risk of HIV-1 infection. We resequenced TRIM5 in chimpanzees and identified two polymorphisms in intron 1 that are shared with humans. Analysis of the gene region encompassing the two trans-specific variants in human populations identified exceptional nucleotide diversity levels and an excess of polymorphism compared to fixed divergence. Most tests rejected the null hypothesis of neutral evolution for this region and haplotype analysis revealed the presence of two deeply separated clades. Calculation of the time to the most recent common ancestor (TMRCA) for TRIM5 haplotypes yielded estimates ranging between 4 and 7 million years. Overall, these data indicate that long-term balancing selection, an extremely rare process outside MHC genes, has maintained trans-specific polymorphisms in the first intron of TRIM5. Bioinformatic analyses indicated that variants in intron 1 may affect transcription factor-binding sites and, therefore, TRIM5 transcriptional activity. Data herein confirm an extremely complex evolutionary history of TRIM5 genes in primates and open the possibility that regulatory variants in the gene modulate the susceptibility to HIV-1.

Neonatal stroke

The perinatal ischemic stroke is defined as "a group of heterogenous conditions with a focal disruption of cerebral flow secondary to an arterial or a venous thrombosis or embolization between the 20 week of foetal life through the 28 post-natal day". Three subgroups are identified: arterial ischemic stroke (AIS), cerebral sinovenous thrombosis (CSVT) and haemorragic infarct. Many strokes are detected in the neonatal period due to early onset seizures, although symptoms can be more subtle leading to a significant delay in the diagnosis. MRI-DWI remains the best tool for a correct diagnosis, extension of the lesion and suggestion of timing. Lesions detected in utero or at early neonatal imaging with signs of tissue loss are considered "foetal stroke". The "neonatal stroke", with the symptoms in the first 4 days, shows the typical abnormalities of the acute phase evolving later in a white matter loss. The AIS shows the ischemic area of restriction at the early DWI in a arterial territory, mainly the middle cerebral artery. The MR-Venogram is useful in the CVST to detect the thrombus in a sinovenous vessel and the potentially associated lesion, such as intraventricular haemorrage and parenchymal oedema. The extension of the lesion and the involvement of the basal ganglia and thalami have a negative prognostic value for the development of hemiplegia especially in the presence of abnormal PLIC. An early diagnosis.

Long-term effects of a program of bladder preservation using chemotherapy plus radiotherapy in muscle invasive bladder cancer (BC). Analysis of biologic predictive factors and health-related quality of life (QOL)

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Background: Long-term effects of a combined approach of transurethral resection (TUR) plus chemotherapy (CT) and pelvic radiotherapy (RT) in terms of bladder preservation, survival, QOL are largely unknown. Moreover we investigated whether p53, Ki67, bcl-2, c-erbB-2 protein expression predict the achievement of a complete response (CR). Methods: From March 1994 to June 2000, 75 pts with muscle invasive BC were treated with a bladder sparing approach including an initial TUR, 3 cycles of CT (cisplatin + 5- FU) alternating with pelvic RT (40 Gy). At the response evaluation, pts with biopsy proven residual disease were considered incomplete responders (IR) and underwent immediate cystectomy. Pts with CR were treated with two additional CT cycles plus a bladder RT boost (20- 24 Gy). Paraffin embedded blocks of the primary tumors were collected and Ki67, p53, bcl-2 and c-erbB-2 protein expression were evaluated in a blind fashion. The Expanded Prostate Cancer Index Composite (EPIC) scores for urinary function, (especially storage, voiding symptoms and bowel function) was used to explore QOL in bladder preserved and compared with a group of matched patients treated by radical cystectomy only. Results: Median age was 67 yrs (range 42–80); T2a-T2b: 42%; T3a-T3b: 47%; T4a: 11%; G3: 88%; hydronephrosis: 32%. Overall, 56 (74.7%) pts achieved a CR and the achievement of a CR was significantly related to lower T stage (p= 0.002), high Ki67 (p=0.001), absence of hydronephrosis (p= 0.007) and high p53 overexpression (p=0.007). Multivariate analysis showed that only a low T stage (p=0.002) and high p53 expression (p=0.043) predict the obtaining of a CR. At 5 years of follow-up, 44 (59%) were alive and in 33 of them (75%) bladder was preserved; after 10-years 28 (37.3%) were alive and in 23 of them (82%) bladder was preserved. Analysis of QOL scores is ongoing. Conclusions: This approach induces a long term survival similar to radical cystectomy with a high rate of bladder preservation and represents a valid treatment for muscle invasive BC. Overexpression of p53 is a predictive marker for the obtaining of CR and for bladder preservation.

No significant financial relationships to disclose.

Pharyngeal pressure value using two continuous positive airway pressure devices

The aim of the study was to measure the difference between the set continuous positive airway pressure (CPAP) value and the pharyngeal pressure reading during CPAP in premature infants with mild respiratory distress syndrome, using two different devices: hood CPAP and the conventional nasal system. The preliminary results suggest that hood CPAP may produce more stable pharyngeal pressure than the conventional nasal device.

Prenatal diagnosis and postnatal management of congenital laryngeal atresia in a preterm infant

Laryngeal atresia is a rare congenital cause of high airway obstruction that can lead to death if not correctly recognized and treated at birth. Postnatal management is difficult and the prognosis is often poor. We report a case of prenatal diagnosis of laryngeal atresia in a fetus that was delivered preterm at 29 weeks of gestation. Tracheotomy was performed as an ex utero intrapartum treatment (EXIT) to guarantee patent airway, and laryngotracheoplasty was performed at 22 months of corrected age. A favorable ventilatory and neurodevelopmental outcome was observed at 33 months of age.

The effects of an early developmental mother-child intervention program on neurodevelopment outcome in very low birth weight infants: a pilot study

BACKGROUND

Several studies report increased minor neurodevelopment dysfunctions in children born very low birth weight (VLBW). Usefulness of preventive early intervention programs to improve neurodevelopment outcome of VLBW infants is still under investigation.

AIMS

To evaluate the effects of an early post-discharge developmental mother-child intervention program on neurodevelopment outcome at 36 months in VLBW infants.

STUDY DESIGN

Prospective study.

SUBJECTS

36 VLBW infants ([mean (S.D.)] birthweight=864 g (204 g); gestational age=27.9 weeks (2.4 weeks)), consecutively born January-August 2001, randomized in intervention and control groups.

OUTCOME MEASURES

Neurodevelopment assessment at 36 months of chronological age with use of the Griffiths Mental Development Scale and related subscales.

RESULTS

At 36 months of chronological age, as compared to controls, children in intervention group exhibited higher scores in personal-social subscales ([mean (S.D.)]=101.4 (9.3) vs. 92.9 (12.1), P=0.02), eye-hand coordination (92.7 (4.5) vs. 87.1 (9.9), P=0.041), practical reasoning (98.6 (8.2) vs. 89.4 (10.1), P=0.01). Development Scale were 97.6 (5.5) and 92.4 (9.9), respectively, in intervention and control groups (P=0.074).

CONCLUSIONS

Early post-discharge developmental mother-child intervention program may have a positive effect on later neurodevelopment outcome of VLBW children.