Cyclic nucleotide-dependent relaxation in human umbilical vessels.

Umbilical vessels have a low sensitivity to dilate, and this property is speculated to have physiological implications. We aimed to investigate the different relaxing responses of human umbilical arteries (HUAs) and veins (HUVs) to agonists acting through the cAMP and cGMP pathways. Vascular rings were suspended in organ baths for isometric force measurement. Following precontraction with the thromboxane prostanoid (TP) receptor agonist U44069, concentration-response curves to the nitric oxide (NO) donor sodium nitroprusside (SNP), the soluble guanylate cyclase (sGC) stimulator BAY 41-2272, the adenylate cyclase (AC) activator forskolin, the ß-adrenergic receptor agonists isoproterenol (ADRB1), salmeterol (ADRB2), and BRL37344 (ADRB3), and the phosphodiesterase (PDE) inhibitors milrinone (PDE3), rolipram (PDE4), and sildenafil (PDE5) were performed. None of the tested drugs induced a relaxation higher than 30% of the U44069-induced tone. Rings from HUAs and HUVs showed a similar relaxation to forskolin, SNP, PDE inhibitors, and ADRB agonists. BAY 41-2272 was significantly more efficient in relaxing veins than arteries. ADRB agonists evoked weak relaxations (< 20%), which were impaired in endothelium-removed vessels or in the presence of the NO synthase inhibitor L-NAME, sGC inhibitor ODQ. PKA and PKG inhibitors impaired ADBR1-mediated relaxation but did not affect ADRB2-mediated relaxation. ADRB3-mediated relaxation was impaired by PKG inhibition in HUAs and by PKA inhibition in HUVs. Although HUA and HUV rings were relaxed by BRL37344, immunohistochemistry and RT-qPCR analysis showed that, compared to ADRB1 and ADRB2, ADRB3 receptors are weakly or not expressed in umbilical vessels. In conclusion, our study confirmed the low relaxing capacity of HUAs and HUVs from term infants. ADRB-induced relaxation is partially mediated by endothelium-derived NO pathway in human umbilical vessels.

Preliminary Experience With Hypothermic Oxygenated Machine Perfusion in an Italian Liver Transplant Center.

BACKGROUND: Machine perfusion is increasingly utilized in liver transplantation to face the detrimental consequences of the use of extended-criteria donors. Hypothermic oxygenated machine perfusion (HOPE) appears to be more protective relative to static cold storage. Conversely, normothermic machine perfusion (NMP) allows a better graft evaluation. We describe a pilot prospective study on machine perfusion in selected grafts. METHODS: HOPE was executed for all the grafts procured from donors after cardiac death (DCDs) and for livers from donors after brain death (DBDs) requiring prolonged preservation time. NMP was used when a more precise evaluation was needed. Both HOPE and NMP were performed through the portal vein and hepatic artery. RESULTS: From July 2016 to November 2017, we performed 7 HOPE procedures: 5 for DCD and 2 for DBD grafts. Two livers presented with macrovesicular steatosis >30% (1 DCD and 1 DBD). HOPE lasted 240 minutes (180-320 min) with a total ischemia time of 575 minutes (410-810 min). Six grafts were successfully transplanted. One DCD graft required additional evaluation using NMP. The graft was then discarded due to extensive hepatocellular necrosis. In the post-transplant course, acute and chronic renal failure were the main complications affecting 3 and 2 recipients, respectively. In our series, steatosis was the main risk factor for kidney injury. Patient and graft survival rate was 100% and no ischemic cholangiopathies were observed after 270 days (106-582 days). CONCLUSIONS: Our study confirms HOPE safety and efficacy for DCD and DBD grafts. These data are particularly significant for DCD management in the Italian setting where the mandatory 20-minute hands-off interval before death declaration further prolongs warm ischemia time.

Severe idiopathic pulmonary fibrosis: A clinical approach.

Idiopathic pulmonary fibrosis (IPF) is a devastating progressive disease associated with a high mortality rate. Novel antifibrotic therapies have been recently demonstrated to slow disease progression and improve survival. However, the management of IPF remains a difficult challenge, since lung complications can still occur, particularly in patients with advanced-stage disease. This paper highlights the most common complications and difficult tasks related to severe IPF such as acute exacerbation of the disease, development of lung cancer, rapid disease progression, and indication for lung transplantation.

Negative Pressure Wound Treatment of Infections Caused By Extensively Drug-Resistant Gram-Negative Bacteria After Liver Transplantation: Two Case Reports.

Although survival after liver transplantation (LT) has progressively improved over the last years, an increased prevalence of clinically relevant infections in LT patients is well documented. In particular, the spread of infections sustained by extensively drug-resistant bacteria (XDR) produced an increase in the incidence of wound infections. Implementation of treatments for these life-threatening events is mandatory. This study describes 2 LT patients in whom XDR wound infection was effectively treated using negative pressure wound treatment (NPWT) combined with targeted local and systemic antibiotic therapy. Over the last 3 years, 2 of 8 patients with XDR infection admitted to our unit developed wound infection caused by XDR Klebsiella pneumoniae (KP-XDR). Positive results of the abdominal fluid culture and of the wound swab for KP-XDR were followed by sepsis. In both cases wound debridement was required and deep fascial layer dehiscence was detected. Combination antibiotic therapy was administered for sepsis treatment and, after failure of conventional NPWT, a NPWT with local instillation (NPWTi; V.A.C.-Ulta/VeraFlo-Instillation Therapy-KCI USA, Inc., San Antonio, TX, USA) of colistin-rifampicin was applied. After NPWTi application a reduction in bacterial load and exudate was observed with reduction in inflammatory markers. A complete healing of wound was achieved and both patients are currently alive. Instillation and NPWT are widely discussed in the literature. Results of the present study indicate beneficial effects of NPWT combined with targeted local and systemic antibiotic therapy; in both cases a life-threatening complication was cured. We consider local instillation of selected antibiotics applied to NPWTi a valuable tool for deep wound infection sustained by XDR bacteria.

A review of the effects of dietary silicon intake on bone homeostasis and regeneration.

OBJECTIVE: Increasing evidences suggest that dietary Silicon (Si) intake, is positively correlated with bone homeostasis and regeneration, representing a potential and valid support for the prevention and improvement of bone diseases, like osteoporosis. This review, aims to provide the state of art of the studies performed until today, in order to investigate and clarify the beneficial properties and effects of silicates, on bone metabolism. METHODS: We conducted a systematic literature search up to March 2013, using two medical databases (Pubmed and the Cochrane Library), to review the studies about Si consumption and bone metabolism. RESULTS: We found 45 articles, but 38 were specifically focused on Si studies. CONCLUSION: RESULTS showed a positive relationship between dietary Si intake and bone regeneration.

Apolipoprotein E deficiency and a mouse model of accelerated liver aging.

The liver is the central metabolic organ which regulates several key aspects of lipid metabolism. The liver changes with age leading to an impaired ability to respond to hepatic insults and an increased incidence of liver disease in the elderly. Apolipoprotein E (ApoE) null mice have proved to be a very popular model to study spontaneous atherosclerosis, but recently it has been demonstrated that in ApoE-/- mice liver there are enzymatic and structural alterations, normally linked to the age. The purpose of this study was to consider ApoE-/- mice as a model for oxidative stress induced hepatic disease and to clarify how ApoE inactivation accelerates the aging process and causes liver disease.We used ApoE null mice and control mice at different ages (6 weeks and 15 months).Liver morphological damage as well as proteins involved in oxidative stress and liver ageing were all analyzed.Our study showed that ApoE null mice develop important age-related changes including oxidative stress, pseudocapillarization, increased polyploidy, decreased hepatocyte number and increased nuclear size. Our findings provide evidence that hypercholesterolemic ApoE-/- mice are more likely to develop severe liver injury, suggesting that in addition to vascular disease, increased cholesterol products and oxidative stress may also play a role in accelerating the progression of aging in the liver.

Role of apolipoprotein E in renal damage protection.

It is well-known that nephrotic syndrome and chronic renal failure are associated with lipid and lipoprotein abnormalities. For a long time, it has been thought that hyperlipidemia is a secondary and insignificant condition of these renal injuries. Recently, it has been shown that dyslipidaemia may contribute to the development and progression of chronic kidney disease. Apolipoprotein E (apoE) null mice are a very popular model for studying spontaneous hypercholesterolemia, but only limited data are available for the role of apolipoprotein E in kidney disease. The purpose of this study is to evaluate kidney disease in apolipoprotein E deficient mice. For this study, apoE null mice and control mice at different ages (6 weeks and 15 months) were used. Kidney morphological damage and proteins involved in oxidative stress and aging (TNF-α and NF-kB) were analyzed. ApoE deficient mice have morphological alterations that are the hallmark of kidney pathogenesis, which increase with the age of the animals. In apoE null mice kidneys, there is also increased oxidative stress as compared to control mice at the same age and fewer antioxidant enzymes. Our findings add to the growing list of protective effects that apoE possesses.

PPADS, a purinergic antagonist reduces Fos expression at spinal cord level in a mouse model of mononeuropathy.

Recent evidence suggest that ATP plays a role as an endogenous pain mediator generating and/or modulating pain signaling from the periphery to the spinal cord. In this study we evaluated the effects of intraperitoneal administration of P2 receptor antagonist, pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), evaluating pain related behaviours and monitoring the expression of Fos, a marker of activated neurons, in an experimental mouse model of neuropathic pain (sciatic nerve tying). The PPADS administration decreased both tactile allodynia and thermal hyperalgesia in a time and dose dependent manner. The dose of 25 mg/kg PPADS completely reversed nociceptive hypersensitivity. Moreover, non-noxious stimulation induced an increase of Fos positive neurons in the spinal cord of animals with tying of sciatic nerve. PPADS administration partially reversed this increase. These results suggest that PPADS reduces neuronal activation at spinal cord level and that P2 receptors are involved in the retrograde signalling progress exciting sensory spinal neurons.

Antimicrobial properties of alpha-MSH and related synthetic melanocortins.

The natural antimicrobial peptides are ancient host defense effector molecules, present in organisms across the evolutionary spectrum. Several properties of alpha-melanocyte stimulating hormone (alpha-MSH) suggested that it could be a natural antimicrobial peptide. Alpha-MSH is a primordial peptide that appeared during the Paleozoic era, long before adaptive immunity developed and, like natural antimicrobial molecules, is produced by barrier epithelia, immunocytes, and within the central nervous system. alpha-MSH was discovered to have antimicrobial activity against two representative pathogens, Staphylococcus aureus and Candida albicans. The candidacidal influences of alpha-MSH appeared to be mediated by increases in cell cyclic adenosine monophosphate (cAMP). The cAMP-inducing capacity of alpha-MSH likely interferes with the yeast's own regulatory mechanisms of this essential signaling pathway. It is remarkable that this mechanism of action in yeast mimics the influences of alpha-MSH in mammalian cells in which the peptide binds to G-protein-linked melanocortin receptors, activates adenylyl cyclase, and increases cAMP. When considering that most of the natural antimicrobial peptides enhance the local inflammatory reaction, the anti-inflammatory and antipyretic effects of alpha-MSH confer unique properties to this molecule relative to other natural antimicrobial molecules. Synthetic derivatives, chemically stable and resistant to enzymatic degradation, could form the basis for novel therapies that combine anti-inflammatory and antimicrobial properties.

Change in gene expression profile induced by alpha-melanocyte stimulating hormone in a malignant mesothelioma cell line.

We have previously reported that the peptide a-melanocyte stimulating hormone (alpha-MSH) has antiproliferative effects in human malignant mesothelioma cells. To determine the molecular mechanisms underlying such effects, we investigated the changes in gene expression profile induced by the alpha-MSH analog [Nle4 -DPhe7 ]-alpha-MSH (NDP-alpha-MSH) in a human malignant mesothelioma cell line. The cDNA macroarray technique revealed changes in expression of genes involved in cell growth, adhesion, signal transduction, and transcription. In particular, NDP-alpha-MSH down-regulated expression of B-Myb and Myc, two oncogenes considered of paramount importance for cell proliferation and cancer. Further, NDP-alpha-MSH exerted a favorable transcriptional regulation of certain integrins and their signaling pathways. Finally, peptide treatment was associated with a prominent inhibition of IL-13, a cytokine with tumor-promoting effects. The data indicate that the influences of alpha-MSH extend beyond the established anti-inflammatory effects in normal cells to include cell cycle regulatory properties in malignant cells.

Defense mechanisms and personality disorders.

The evaluation of defense mechanisms represents one of the most promising fields in the psychodynamic-oriented empirical research on personality disorders (PDs). This study examines the association between DSM-IV PDs and defense mechanisms. We evaluated a sample of 50 adult outpatients seeking personality assessment and psychotherapeutic treatment. PDs have been assessed using the Structured Clinical Interview for DSM-IV Personality Disorder, version 2.0. Defense mechanisms have been evaluated by a group of trained clinical psychologists and psychiatrists (interrater reliability from .61 to .95) using Perry's Defense Mechanism Rating Scale. Our results support the hypothesis that some defense mechanisms underlie PDs and that defenses call for further attention as we assess PDs.

Scanning laser ophthalmoscopy of the optic disc at the level of the lamina cribrosa.

PURPOSE: To determine the suitability and reproducibility of optic disc morphometry performed on images focused at the level of the lamina cribrosa, obtained by means of the scanning laser ophthalmoscope (SLO). METHODS: Twenty-one eyes were imaged with argon blue and green, helium neon red and diode infrared laser sources of a scanning laser ophthalmoscope. Five images of the optic disc at the level of the lamina cribrosa were taken for each patient, digitized and traced by three trained observers, in order to identify the external contour of the optic disc and the inner edge of the neuroretinal rim. Dedicated software allowed the contours to be traced on the video and an estimate of the real sizes of optic disc parameters to be obtained according to Littman's equation. Standard deviation (SD) and coefficient of variation (CV) were used to determine the intra- and inter-observer reproducibility in measuring disc, dark annulus (DA), and reflective center (RC) areas, DA area/disc area (DA/D) and RC area/disc area (RC/D) ratios of each set of images taken with all laser wavelengths. RESULTS: A high contrast between the dark annulus of the lamina and the central highly reflective area was achieved at all laser wavelengths. The ranges of CVs for all of the observers, using all the laser wavelengths, were as follows: disc: 0.018-0.036; dark annulus: 0.015-0.039; reflective center: 0.014-0.031; DA/D: 0.005-0.01; RC/D: 0.007-0.018. No significant difference was observed between the measurements performed on the images acquired, using the different laser wavelengths. CONCLUSIONS: SLO imaging of the optic disc at the level of the lamina cribrosa proved to be suitable and highly reproducible at all laser wavelengths. The coefficients of variation of the measurements of optic disc parameters obtained using this technique are smaller than those obtained by means of conventional photographic methods.

Microperimetry of localized retinal nerve fiber layer defects.

The aim of this study was to determine the sensitivity of retinal areas involved in a localized retinal nerve fiber layer (RNFL) defect and to assess correlations between microperimetry and the standard full threshold central 30 deg visual field test. Twenty-five patients with focal RNFL defects, evaluated by means of Argon-blue scanning laser ophthalmoscopy (SLO), underwent an automated 30 deg central visual field examination and a microperimetry with SLO. Microperimetry was performed according to standard procedures (infrared laser for fundus imaging; HeNe laser for 10 candles/m2 background illumination, fixation aid and generation of stimuli; manual fundus tracking). The size of stimuli was Goldmann III with 0.1 sec duration. In eyes with focal RNFL defects a deep microperimetric scotoma of at least 5 dB was found in 12 cases and a mild scotoma (1-4 dB) in 13 cases. These scotomas were mainly located throughout the whole defect or grouped in the temporal or nasal sides of the defect and were characterized by sharp and well-defined borders. With automated perimetry, a scotoma, defined by a single point depression of at least 10 dB or a depression of at least 5 dB in two or more contiguous points corresponding to the RNFL, defect, was found in only 14 out of 25 eyes with microperimetric defect. Focal RNFL defects correspond to localized areas of depressed retinal sensitivity as evaluated by microperimetry. The close correspondence between structural and microperimetric findings suggests that, in hypertensive eyes also, localized RNFL defects correspond to visual dysfunction possibly associated with substantial atrophy of ganglion cells.

Correlation between the progression of optic disc and visual field changes in glaucoma.

Visual field test and optic disc evaluation are the standard examination techniques used to detect the onset and progression of glaucoma. This explorative study was performed to assess the temporal correlation between visual field and optic disc changes in eyes with ocular hypertension and well-established glaucoma. Eighty-six hypertensive and 16 glaucomatous eyes were followed up for a period of up to 9 years (average 4.4 yrs) using kinetic and computerized static perimetry and optic disc manual morphometry. Perimetric changes were based on a series of strict criteria and optic disc changes were based as a reduction in the baseline rim area/disc area ratio (R/D) measurement exceeding the 99% confidence interval for intraobserver reproducibility (7.7%). Optic disc changes were found prior to visual field changes in four hypertensive eyes, whereas visual field changes were found prior to disc changes in six glaucomatous eyes (p = 0.042). The results of our explorative study suggest that quantitative optic disc analysis may be more sensitive than visual field examination in detecting early glaucomatous changes, whereas visual field examination may be more sensitive than quantitative optic disc analysis in detecting glaucomatous progressions in eyes with well established glaucoma.

Arteriovenous crossing as a risk factor in branch retinal vein occlusion.

To evaluate the importance of the position of the artery anterior to the vein in the arteriovenous crossing to the pathogenesis of first- and second-order branch retinal vein occlusion, we studied the fluorescein angiograms of 65 patients with branch retinal vein occlusion (65 eyes). The corresponding crossing in the opposite arcade (superior or inferior) served as the control. In a statistically significant percentage of crossings, the arteries were anterior to the veins in second-order branches (odds ratio, 6.66; 95% confidence interval, 1.98 to 32.33; chi 2, 12.56; P = .000394). However, their position was not found to be important in the pathogenesis of first-order occlusions (odds ratio, 1.3; 95% confidence interval, 0.23 to 9.01; chi 2, 0.14; P = .708281). These results suggest that some differences may exist in the risk factors for branch retinal vein occlusion depending on the site of the occlusion.

Drusen and 'choroidal filling defects': a cross-sectional survey.

The present study was designed as a cross-sectional survey to assess the association between soft drusen and 'choroidal filling defects'. Sixty-eight eyes presenting hard drusen and 58 eyes with soft drusen of 126 subjects with an age range of 45-83 years were examined in the present study. Choroidal filling defects were present in 13 out of 68 (19.1%) patients with hard drusen and 29 out of 58 (50%) with soft drusen (chi 2 square = 13.4; p < 0.0001 and an odds ratio = 4.2 with 95% CI 1.9-9.3). Age, ocular and systemic hypertension, and diabetes did not influence the results. The association between soft drusen and choroidal filling defects, found in our study, suggests that these abnormalities are possibly due to changes in the staining or permeability properties of Bruch's membrane rather than to a defect in the choroidal blood supply. Soft drusen and choroidal filling defects may both be caused by an accumulation of hydrophobic material within the Bruch's membrane, which is discrete in the case of drusen and diffuse in the case of choroidal filling defects. Choroidal filling defects and soft drusen may represent useful clinical sign of hydrophobicity of Bruch's membrane.