Comprehensive longitudinal non-invasive quantification of healthspan and frailty in a large cohort (n = 546) of geriatric C57BL/6 J mice

Frailty is an age-related condition characterized by a multisystem functional decline, increased vulnerability to stressors, and adverse health outcomes. Quantifying the degree of frailty in humans and animals is a health measure useful for translational geroscience research. Two frailty measurements, namely the frailty phenotype (FP) and the clinical frailty index (CFI), have been validated in mice and are frequently applied in preclinical research. However, these two tools are based on different concepts and do not necessarily identify the same mice as frail. In particular, the FP is based on a dichotomous classification that suffers from high sample size requirements and misclassification problems. Based on the monthly longitudinal non-invasive assessment of frailty in a large cohort of mice, here we develop an alternative scoring method, which we called physical function score (PFS), proposed as a continuous variable that resumes into a unique function, the five criteria included in the FP. This score would not only reduce misclassification of frailty but it also makes the two tools, PFS and CFI, integrable to provide an overall measurement of health, named vitality score (VS) in aging mice. VS displays a higher association with mortality than PFS or CFI and correlates with biomarkers related to the accumulation of senescent cells and the epigenetic clock. This longitudinal non-invasive assessment strategy and the VS may help to overcome the different sensitivity in frailty identification, reduce the sample size in longitudinal experiments, and establish the effectiveness of therapeutic/preventive interventions for frailty or other age-related diseases in geriatric animals.

A novel collagenase from Vibrio Alginolyticus: experimental study for Dupuytren's disease

OBJECTIVE

Dupuytren contracture (DC) is a highly prevalent hand affection in which contracted fingers compromise hand function. It is a benign fibroproliferative condition affecting the hand palmar fascia with a deposition of excess matrix proteins in the extracellular space of the palmar aponeurosis. In particular type III over type I collagen V. Alginolyticus collagenase (CVA), is a new enzyme that is fully active on the collagen filaments and inactive on other components of the dermal extracellular matrix. The aim of this study is to evaluate the safety and effectiveness of an intra-lesional injection of CVA on an animal model of subcutaneous fibrosis mimicking the pathological anatomy of the cord of Dupuytren's disease.

MATERIALS AND METHODS

We performed an in vivo study on 27 rats that were randomized into four groups, and we evaluated macroscopic and microscopic analysis examining the inflamed cell population and the extracellular matrix.

RESULTS

In all cases, no skin necrosis, skin tears or wound dehiscence were recorded, demonstrating the safety of the CVA in contrast to group D which had full-thickness skin necrosis, and this is confirmed by the microscopic analysis of the samples treated with CVA, where no hematomas are found around the fibrotic area with the absence of leukocyte infiltrates and macrophages.

CONCLUSIONS

CVA is confirmed to be selective for collagens I and III, reducing the risk of vascular lesions or skin ulcerations.

Effects of Human LAV-BPIFB4 Gene Therapy on the Epigenetic Clock and Health of Aged Mice

The homozygous genotype of the Longevity-Associated Variant (LAV) in Bactericidal/Permeability-Increasing Fold-Containing Family B member 4 (BPIFB4) is enriched in long-living individuals of three independent populations and its genetic transfer in C57BL/6J mice showed a delay in frailty progression and improvement of several biomarkers of aging and multiple aspects of health. The C57BL/6J strain is a suitable model for studying therapies aimed at extending healthy aging and longevity due to its relatively short lifespan and the availability of aging biomarkers. Epigenetic clocks based on DNA methylation profiles are reliable molecular biomarkers of aging, while frailty measurement tools are used to evaluate overall health during aging. In this study, we show that the systemic gene transfer of LAV-BPIFB4 in aged C57BL/6J mice was associated with a significant reduction in the epigenetic clock-based biological age, as measured by a three CpG clock method. Furthermore, LAV-BPIFB4 gene transfer resulted in an improvement of the Vitality Score with a reduction in the Frailty Index. These findings further support the use of LAV-BPIFB4 gene therapy to induce beneficial effects on epigenetic mechanisms associated with aging and frailty in aged mice, with potential implications for future therapies to prevent frailty in humans.

Deep sedation with dexmedetomidine administered by electrophysiologists during COVID-19 pandemic compared with propofol administered by anesthesiologists for ablation of atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

COVID-19 pandemic, limiting the availability of anesthesiologists, has impacted heavily on the organization of invasive cardiac procedures such as transcatheter atrial fibrillation (AF) ablation.

Purpose

We compared the safety and efficacy of deep sedation with dexmedetomidine administered by electrophysiologists without anesthesiologist supervision, against the standard protocol performed with propofol.

Methods

We retrospectively included all AF ablation procedures performed in 2020: 23 patients sedated with 1% propofol (2 ml bolus followed by infusion starting at 1 mg/Kg/h), 26 patients with dexmedetomidine (infusion starting at 0.7 mcg/Kg/h). Both groups additionally received 1 mcg/Kg of midazolam as a single bolus and 0.05 mg single boluses of fentanyl prior to ablation on each pair of pulmonary veins (PV). Primary outcomes were oxygen desaturation (< 90%) or need for assisted ventilation/intubation, bradycardia (heart rate < 45 bpm) and persistent hypotension (systolic blood pressure < 90 mmHg).

Results

Baseline characteristics and hemodynamic variables did not differ between the two groups (all p > 0.05). In 8/23 (35%) patients propofol infusion velocity reduction was necessary to maintain the hemodynamic values, compared to 7/26 (27%) with dexmedetomidine.

Inter-group comparison of hemodynamic variables during the procedure showed no statistically significant difference, despite a trend in favor of dexmedetomidine (3 respiratory depressions and 3 persistent hypotension episodes with propofol vs. 0 with dexmedetomidine; p = 0.057).

Conclusion

Deep sedation with dexmedetomidine administered by electrophysiologists without anesthesiologist supervision is safe and effective for AF transcatheter ablation. A trend towards a lower incidence of hypotension and respiratory depression was noted when compared to propofol.

Syncope: a worrisome presenting symptom during the first wave of COVID-19 in Italy

Background

COronaVIrus Disease 19 (COVID-19) pandemic is a global health emergency. Since the first reported cases in Asia, the virus has now spread worldwide. Given its high contagiousness, one of the greatest challenges is early detection of infected patients. People affected by COVID-19 have had a wide range of presenting symptoms, from very mild to severe, including fever, cough, shortness of breath, gastrointestinal upset, anosmia and ageusia among others. Syncope as the presenting symptom of COVID-19 has been reported in case series or small sample size retrospective studies with variable results in terms of incidence, characteristics and outcomes.

Purpose

The aim of the present analysis is to investigate all consecutive patients with COVID-19 who presented with syncope during the first wave of the pandemic to a high-volume Emergency Department (ED) in Italy.

Methods

A total of 569 patients diagnosed with COVID-19 by positive nose and throat swab and admitted to the hospital between February 20th, 2020 (day of first reported COVID-19 case in Italy) and April 23rd, 2020 were retrospectively evaluated.

Results

Syncope has been reported as the initial symptom which prompted medical attention in 46 out of 569 patients (8%). Mean age of patients presenting with syncope was 72±15 years, 28 were males. Baseline patients' clinical characteristics are reported in Table 1. In 18 out of 46 patients (39%) syncope was an isolated finding, being fever and cough the two most commonly associated symptoms. Arrhythmic etiology was excluded since no arrhythmia was observed at device interrogation or with ECG/prolonged heart monitoring during hospitalization. No significant abnormalities were present at baseline ECG. At the time of admission, all patients were normotensive, median O2 saturation was 94.5%, median D-dimer 362 ng/ml. One-third of the patients presenting with syncope had a complicated clinical course with quite rapid deterioration requiring non-invasive ventilation (30%) and intensive care unit admission with intubation (11%).

In our group of consecutive patients with COVID-19 who presented with syncope, the mortality rate was surprisingly high, 15/46 (32%), compared to the mortality rate of the COVID population admitted to our hospital with other symptoms 93/523 (18%), p=0.023. Six out of 15 patients died in the ED, mainly during their first day of hospitalization. The other 9 had a quite rapid deterioration in the following days and died within a week (median syncope-to-death time was 7 days).

Conclusion

Despite our new finding needs confirmation in studies with larger sample size, our report shows how syncope may be the presenting symptom of COVID-19. Whether the exact mechanism has to be demonstrated, the mortality rate in patients presenting with syncope is higher than the mortality rate of patients presenting with other symptoms; therefore COVID-19 patients presenting with syncope should be on a watch list for rapid deterioration.

Funding Acknowledgement

Type of funding sources: None.

HeartLogic algorithm for heart failure monitoring in the era of CoViD-19 pandemic and remote monitoring/telemedicine

Background

Due to the current CoViD-19 pandemic, the number of outpatient hospital visits has significantly decreased, creating a fundamental need for telemedicine. Remote monitoring of implantable cardiac devices has emerged as a powerful and well-validated tool to follow patients with heart failure (HF) and cardiac resynchronization therapy (CRTs) devices.

Purpose

The aim of our study was to evaluate the CRT HeartLogic algorithm performance in the detection of HF episodes in a real-life population followed with remote monitoring.

Methods

Fifty-four patient (mean age 73±7 years, 72% males) with HF and reduced left ventricular ejection fraction were implanted with a HeartLogic-enabled CRT device and were enrolled in the Boston Scientific Latitude remote monitoring platform. Remote data were reviewed every month and at the time of an alert. The HeartLogic nominal value of 16 was used to trigger an alert episode. Patients were then contacted by phone and actions were taken to manage the potential HF condition detected by the alert.

Results

During a median follow-up of 12 (6–18) months, the HeartLogic alert was triggered in 9 patients (9/54, 17%). The median time between threshold crossing and a HF clinical event was 11 (2–19) days. The maximum HeartLogic index value was 43 (mean 29±8). Three events occurred after inappropriate discontinuation of HF therapy. All the events required clinical action. Four out of 9 patients required diuretic dosage increase, 1/9 electrical cardioversion for new onset atrial fibrillation, 3/9 hospitalization for i.v. therapy. One patient showed only mild HF symptoms but was found to have concomitant CoViD-19 infection.

Conclusion

The HeartLogic algorithm is useful to detect HF worsening and undertake appropriate clinical actions. Telemedicine and device remote monitoring are very helpful tools allowing early detection of HF-related clinical conditions. This is of utmost importance in the era of CoViD-19 pandemic, when scheduled access to the hospital for routine follow-up appointments might be limited.

Funding Acknowledgement

Type of funding sources: None.

Effects of Normoxia, Hyperoxia, and Mild Hypoxia on Macro-Hemodynamics and the Skeletal Muscle Microcirculation in Anesthetised Rats

Objectives: Excessive oxygen (O₂) administration may have a negative impact on tissue perfusion by inducing vasoconstriction and oxidative stress. We aimed to evaluate the effects of different inhaled oxygen fractions (FiO₂) on macro-hemodynamics and microvascular perfusion in a rat model.

Methods: Isoflurane-anesthetised spontaneously breathing male Wistar rats were equipped with arterial (carotid artery) and venous (jugular vein) catheters and tracheotomy, and randomized into three groups: normoxia (FiO₂ 21%, n = 6), hyperoxia (FiO₂ 100%, n = 6) and mild hypoxia (FiO₂ 15%, n = 6). Euvolemia was maintained by infusing Lactate Ringer solution at 10 ml/kg/h. At hourly intervals for 4 h we collected measurements of: mean arterial pressure (MAP); stroke volume index (SVI), heart rate (HR), respiratory rate (by means of echocardiography); arterial and venous blood gases; microvascular density, and flow quality (by means of sidestream dark field videomicroscopy on the hindlimb skeletal muscle).

Results: MAP and systemic vascular resistance index increased with hyperoxia and decreased with mild hypoxia (p < 0.001 in both cases, two-way analysis of variance). Hyperoxia induced a reduction in SVI, while this was increased in mild hypoxia (p = 0.002). The HR increased under hyperoxia (p < 0.05 vs. normoxia at 3 h). Cardiax index, as well as systemic O₂ delivery, did not significantly vary in the three groups (p = 0.546 and p = 0.691, respectively). At 4 h, microvascular vessel surface (i.e., the percentage of tissue surface occupied by vessels) decreased by 29 ± 4% in the hyperoxia group and increased by 19 ± 7 % in mild hypoxia group (p < 0.001). Total vessel density and perfused vessel density showed similar tendencies (p = 0.003 and p = 0.005, respectively). Parameters of flow quality (microvascular flow index, percentage of perfused vessels, and flow heterogeneity index) remained stable and similar in the three groups.

Conclusions: Hyperoxia induces vasoconstriction and reduction in skeletal muscle microvascular density, while mild hypoxia has an opposite effect.

Skeletal muscle repair in a rat muscle injury model: the role of growth hormone (GH) injection

OBJECTIVE

Muscle injury tends to heal with incomplete functional recovery. Among the growth factors released in the physio-pathological response of muscle lesion, the Insulin-like Growth-Factor-1 (IGF-1) results in an engine factor of the reparation program. The therapeutic use of growth factors has been exploited to improve healing. As IGF-1 is a primary mediator of the effects of growth hormone (GH), we exploited its systemic administration to muscle recovery in a rat model of muscle injury.

MATERIALS AND METHODS

Monolateral lesion of the longissimus dorsi muscle of rats was performed. Animals were divided into 5 groups: four groups for histological studies and serum hormone dosage, whilst the fifth group represented the uninjured control. Rat GH was intraperitoneally administered after 24h from the surgical lesion at three different concentrations (0.1, 0.2, 0.4 mg/kg). At 3 days from surgery, immunohistochemical and histological analyses evaluated the expression of MyoD and Myogenin, and the presence of neovascularization and inflammation, respectively. After 2 months, we analyzed the presence of muscle regeneration and fibrosis.

RESULTS

The treatment with GH resulted in a significant increase in neovascularization and Myogenin expression at 24h from injury in comparison with the control. This suggested speed up biological recovery times. After two-months, a dose-dependent increase of the connective component was observed.

CONCLUSIONS

The potential effect of GH on muscle repair and regeneration, through the activation of satellite cells already demonstrated in vitro, was confirmed in this in vivo experimental approach. This study sheds light on the role of growth factors in damage repair mechanisms to find an appropriate biological treatment for muscle injury.

Implantable cardiac monitor after cryptogenic stroke: atrial fibrillation detection and predictors

Objective

The main objective of our study was to analyze the incidence and predictors of atrial fibrillation (AF) in patients with cryptogenic stroke (CS) who received an implantable cardiac monitor (ICM) at our Institution.

Methods

From November 2013 to October 2017, a total of 133 patients who had suffered a CS were implanted with an ICM after a thorough screening process. The median time between the thromboembolic event and ICM implantation was 64 days [IQ range: 16–111]. All implanted patients were followed with remote monitoring until the first detected episode of AF or up to December 2018. Every remote monitoring transmission and related electrograms were analyzed by the dedicated Electrophysiology Nursing team and confirmed by experienced Electrophysiologists. AF was defined by any episode lasting greater than or equal to 2 minutes.

Results

During a median follow-up of 14.8 months [IQ range: 3.0–31.2], AF was detected in 65 out of 133 patients (48.9%). The median time from ICM implantation and AF detection was 3.5 months [IQ range: 0.9–6.7]. The prevalence of AF was 22.6%, 34.4%, 40.8% and 48.3% at 3, 6, 12 and 24 months respectively. At the multivariate analysis, high premature atrial contractions (PAC) burden and left atrium (LA) dilation were the only independent predictors of AF detection (HR 2.82, 95% CI 1.64–4.83, p&lt;0.001 for PAC; HR 1.75, 95% CI 1.03–2.97, p=0.038 for LA dimension). Patients were dived into categories based on the probability of AF detection (low, intermediate and high risk) and a new risk stratification algorithm was implemented (Figure 1).

Conclusion

After a thorough screening process, AF detection in patients with CS and ILM was quite high. Having a high PAC burden and LA dilation predicted AF episodes at the multivariate analysis. A new risk stratification algorithm was developed.

Figure 1

Funding Acknowledgement

Type of funding source: None

Targeting Multiple Mitochondrial Processes by a Metabolic Modulator Prevents Sarcopenia and Cognitive Decline in SAMP8 Mice

The age-dependent declines of skeletal muscle and cognitive functions often coexist in elderly subjects. The underlying pathophysiological mechanisms share common features of mitochondrial dysfunction, which plays a central role in the development of overt sarcopenia and/or dementia. Dietary supplementation with formulations of essential and branched-chain amino acids (EAA-BCAA) is a promising preventive strategy because it can preserve mitochondrial biogenesis and function. The senescence-accelerated mouse prone 8 (SAMP8) is considered an accurate model of age-related muscular and cognitive alterations. Hence, we aimed to investigate the progression of mitochondrial dysfunctions during muscular and cognitive aging of SAMP8 mice and to study the effects of a novel EAA-BCAA-based metabolic modulator on these changes. We evaluated body condition, motor endurance, and working memory of SAMP8 mice at 5, 9, 12, and 15 months of age. Parallel changes in protein levels of mitochondrial respiratory chain subunits, regulators of mitochondrial biogenesis and dynamics, and the antioxidant response, as well as respiratory complex activities, were measured in the quadriceps femoris and the hippocampus. The same variables were assessed in 12-month-old SAMP8 mice that had received dietary supplementation with the novel EAA-BCAA formulation, containing tricarboxylic acid cycle intermediates and co-factors (PD-0E7, 1.5 mg/kg/body weight/day in drinking water) for 3 months. Contrary to untreated mice, which had a significant molecular and phenotypic impairment, PD-0E7-treated mice showed preserved healthy body condition, muscle weight to body weight ratio, motor endurance, and working memory at 12 months of age. The PD-0E7 mixture increased the protein levels and the enzymatic activities of mitochondrial complex I, II, and IV and the expression of proliferator-activated receptor γ coactivator-1α, optic atrophy protein 1, and nuclear factor, erythroid 2 like 2 in muscles and hippocampi. The mitochondrial amyloid-β-degrading pitrilysin metallopeptidase 1 was upregulated, while amyloid precursor protein was reduced in the hippocampi of PD-0E7 treated mice. In conclusion, we show that a dietary supplement tailored to boost mitochondrial respiration preserves skeletal muscle and hippocampal mitochondrial quality control and health. When administered at the early onset of age-related physical and cognitive decline, this novel metabolic inducer counteracts the deleterious effects of precocious aging in both domains.

A New Animal Model for Pathological Subcutaneous Fibrosis: Surgical Technique and in vitro Analysis

Fibrosis is a condition that affects the connective tissue in an organ or tissue in the restorative or responsive phase as a result of injury. The consequences of excessive fibrotic tissue growth may lead to various physiological complications of deformity and impairment due to hypertrophic scars, keloids, and tendon adhesion without understating the psychological impact on the patient. However, no method accurately quantifies the rate and pattern of subcutaneous induced hypertrophic fibrosis. We, therefore, devised a rodent excisional model to evaluate the extent of fibrosis with talc. Tissue specimens were set on formalin, and paraffin sections for histological, immunohistochemical, and molecular analysis talc was used to induce the fibroproliferative mechanism typical of hypertrophic scars. This pathway is relevant to the activation of inflammatory and fibrotic agents to stimulate human hypertrophic scarring. This model reproduces morpho-functional features of human hypertrophic scars to investigate scar formation and assess potential anti-scarring therapies.

Potential application of berberine in the treatment of Escherichia coli sepsis

Gram-negative sepsis ranks as the leading cause of death in intensive care units. Despite the development of new antibiotics, mortality from gram-negative sepsis remains high. The present study aims to investigate the in vivo effects of berberine (BBR) administration on septic death induced by intraperitoneal Escherichia coli injection. The results showed that (i) single 5 mg/kg dose of BBR increases the survival of septic mice, (ii) BBR administration improves the antimicrobial efficacy of antibiotic drug, (iii) BBR pre-treatment prevents improvements of BBR therapy without affecting the pro-survival effects of antibiotic drug. The effects of BBR administration were associated with immunological alterations represented by changes in CD4+ and CD8+ lymphocytes population and IL-6 and TNF-α production. This study highlighted the benefits of berberine administration as antibiotic adjuvant in E. coli sepsis. Furthermore, information about berberine-induced immunological perturbations and their influence on host response to infection and therapy has been shown.

Anastomotic healing in a rat model of peritonitis after non-steroidal anti-inflammatory drug administration

The tissue inflammatory response can influence the outcome of anastomotic healing. Anastomotic leakage represents a dreadful complication after gastrointestinal surgery, in particular sepsis and intra-abdominal infections impair the restorative process of colic anastomoses. It has been debated whether the administration of nonsteroidal anti-inflammatory drugs (NSAIDs) is a risk factor for dehiscence, since many patients receive NSAIDs in the early postoperative period. Our aim was, for the first time, to analyze the morpho-functional effects of postoperative administration of two commonly used NSAIDs, Diclofenac and Ketorolac, on the healing process of colo-colic anastomoses constructed under condition of fecal peritonitis in a rat model. Sixty adult male rats underwent two surgical procedures: peritonitis induction and colo-colic anastomosis, and were divided into three groups: 20 rats received saline; 20 rats 4 mg/kg Diclofenac and 20 rats 5 mg/kg Ketorolac. We assessed anastomosis strength, morphological features of tissue wound healing, immunohistochemical metalloproteinase 9 (MMP9) expression and collagen deposition and content by Sirius red staining and hydroxyproline level. We found no significant difference in bursting pressure, collagen content and organization and morphological features between the groups, except a significantly reduced presence of inflammatory cells and MMP9 expression in the groups treated with NSAIDs. Our findings showed that Diclofenac and Ketorolac administration did not affect post-surgical healing and did not increase the leakage risk of colo-colic anastomoses during peritonitis.

Aging-Related Expression of Twinfilin-1 Regulates Cholangiocyte Biological Response to Injury

Disorders of the biliary tree develop and progress differently according to patient age. It is currently not known whether the aging process affects the response to injury of cholangiocytes. The aim of this study was to identify molecular pathways associated with cholangiocyte aging and to determine their effects in the biological response to injury of biliary cells. A panel of microRNAs (miRs) involved in aging processes was evaluated in cholangiocytes of young and old mice (2 months and 22 months of age, respectively) and subjected to a model of sclerosing cholangitis. Intracellular pathways that are common to elevated miRs were identified by in silico analysis. Cell proliferation and senescence were evaluated in Twinfilin-1 (Twf1) knocked-down cells. In vivo, senescence-accelerated prone mice (Samp8, a model for accelerated aging), Twf1^-/- , or their respective controls were subjected to DDC (3,5-diethoxycarbonyl-1,4-dihydrocollidine). Cholangiocytes from DDC-treated mice showed up-regulation of a panel of aging-related miRs. Twf1 was identified by in silico analysis as a common target of the up-regulated miRs. Twf1 expression was increased both in aged and diseased cholangiocytes, and in human cholangiopathies. Knock-down of Twf1 in cholangiocytes reduced cell proliferation. Senescence and senescence-associated secretory phenotype marker expression increased in Twf1 knocked-down cholangiocytes following pro-proliferative and pro-senescent (10-day lipopolysaccharide) stimulation. In vivo, Samp8 mice showed increased biliary proliferation, fibrosis, and Twf1 protein expression level, whereas Twf1^-/- had a tendency toward lower biliary proliferation and fibrosis following DDC administration compared with control animals. Conclusion: We identified Twf1 as an important mediator of both cholangiocyte adaptation to aging processes and response to injury. Our data suggest that disease and aging might share common intracellular pathways.

Induction of Mouse Lung Injury by Endotracheal Injection of Bleomycin

Pulmonary fibrosis is a hallmark of several human lung diseases with a different etiology. Since current therapies are rather limited, mouse models continue to be an essential tool for developing new antifibrotic strategies. Here we provide an effective method to investigate in vivo antifibrotic activity of human mesenchymal stromal cells obtained from whole umbilical cord (hUC-MSC) in attenuating bleomycin-induced lung injury. C57BL/6 mice receive a single endotracheal injection of bleomycin (1.5 U/kg body weight) followed by a double infusion of hUC-MSC (2.5 x 10⁵) into the tail vein, 24 h and 7 days after the bleomycin administration. Upon sacrifice at days 8, 14, or 21, inflammatory and fibrotic changes, collagen content, and hUC-MSC presence in explanted lung tissue are analyzed. The injection of bleomycin into the mouse trachea allows the direct targeting of the lungs, leading to extensive pulmonary inflammation and fibrosis. The systemic administration of a double dose of hUC-MSC results in the early blunting of the bleomycin-induced lung injury. Intravenously infused hUC-MSC are transiently engrafted into the mouse lungs, where they exert their anti-inflammatory and antifibrotic activity. In conclusion, this protocol has been successfully applied for the preclinical testing of hUC-MSC in an experimental mouse model of human pulmonary fibrosis. However, this technique can be easily extended both to study the effect of different endotracheally administered substances on the pathophysiology of the lungs and to validate new anti-inflammatory and antifibrotic systemic therapies.

Efficacy of Pexiganan Combination with Tigecycline in a Mouse Model of Pseudomonas aeruginosa Sepsis

BACKGROUND

Pseudomonas aeruginosa is a gram-negative pathogen, associated with a severe mortality rate. It is also difficult to treat due to numerous resistance mechanisms to a wide range of antibiotics.

OBJECTIVE

Evaluate the activity of pexiganan, an antimicrobial peptide, in combination with two clinical antibiotics (azithromycin and tigecycline) that are not active against P. aeruginosa.

METHODS

Ten clinical P. aeruginosa were isolated from urinary tract infections, blood culture, skin infections and respiratory tract infections. Minimum inhibitory concentrations (MICs) and synergies were evaluated by broth microdilution, checkerboard assays and time-kill studies. In vitro synergy was confirmed with an in vivo experiment using a murine model of sepsis.

RESULTS

Pexiganan MICs were included between 2 and 16 mg/L. Tigecycline and azithromycin MICs were high as expected (4-64 mg/L and 32-256 mg/L, respectively). Pexiganan and azithromycin combination resulted to be additive or indifferent while tigecycline and pexiganan combination was synergic against seven out of ten P. aeruginosa and additive against the other strains. In vivo experiment confirmed the in vitro synergy, denoting a significative reduction of bacteria in mice treated with pexiganan and tigecycline combination.

CONCLUSION

Antimicrobial peptides are molecules that could be useful in the fight against infections and pexiganan seems to be one of the most promising. Our results demonstrated that, in association with tigecycline, pexiganan administration could overcome antibiotic resistance and increase the effectiveness of treatment against P. aeruginosa sepsis.

Recovery from mild Escherichia coli O157:H7 infection in young and aged C57BL/6 mice with intact flora estimated by fecal shedding, locomotor activity and grip strength

Escherichia coli 0157:H7 is a food-borne pathogen that can cause severe complications in vulnerable populations. Mouse infection models of E. coli 0157:H7 are usually developed under severe animal suffering classification by depleting the normal flora, in which age plays a role.

OBJECTIVE

To develop a refined method for longitudinal monitoring of E. coli 0157:H7 in young and old mice with intact flora.

METHODS

We applied discriminant analysis and computed composite standardized scores from 19 variables obtained from physiological parameters, analysis of locomotor activity, grip strength measurement and fecal shedding in 16 aged and 16 young C57BL/6 mice after two mild oral challenges of E. coli 0157:H7. The resulting scores were validated in another experiment performed in 24 aged and 24 young mice including a group (8 aged and 8 young mice) treated with oxytetracycline.

RESULTS

We show that our scores are significantly affected in the post-infection period and that can be used to measure and compare the recovery time after a treatment. The scores are most sensitive when separately developed in young and aged mice.

CONCLUSIONS

We developed a method that minimizes the level of animal suffering and that can be applied in preclinical testing of new therapies.

Mesenchymal stromal cells from human umbilical cord prevent the development of lung fibrosis in immunocompetent mice

Lung fibrosis is a severe condition resulting from several interstial lung diseases (ILD) with different etiologies. Current therapy of ILD, especially those associated with connective tissue diseases, is rather limited and new anti-fibrotic strategies are needed. In this study, we investigated the anti-fibrotic activity in vivo of human mesenchymal stromal cells obtained from whole umbilical cord (hUC-MSC). Adult immunocompetent C57BL/6 mice (n. = 8 for each experimental condition) were injected intravenously with hUC-MSC (n. = 2.5 × 10⁵) twice, 24 hours and 7 days after endotracheal injection of bleomycin. Upon sacrifice at days 8, 14, 21, collagen content, inflammatory cytokine profile, and hUC-MSC presence in explanted lung tissue were analyzed. Systemic administration of a double dose of hUC-MSC significantly reduced bleomycin-induced lung injury (inflammation and fibrosis) in mice through a selective inhibition of the IL6-IL10-TGFβ axis involving lung M2 macrophages. Only few hUC-MSC were detected from explanted lungs, suggesting a “hit and run” mechanism of action of this cellular therapy. Our data indicate that hUC-MSC possess strong in vivo anti-fibrotic activity in a mouse model resembling an immunocompetent human subject affected by inflammatory ILD, providing proof of concept for ad-hoc clinical trials.

rhVEGF and Experimental Rat Skin Flaps: Systemic or Local Administration and Morphological Characteristics

Skin flap survival is a significant problem in skin surgery; in particular, inadequate arterial or venous blood supply results in necrosis of the distalmost portion. The aim of this study was to evaluate the ability of Vascular Endothelial Growth Factor (VEGF) of modifying the morphological features of skin flaps. Bilateral epigastric skin flaps were raised in 16 Wistar male rats. The epigastric artery and vein of the left flaps were clamped and then injected with rhVEGF (8 rats) or saline (8 rats). The right flaps were not clamped and received rhVEGF or saline systemically. The rats were euthanized on the seventh day and flap skin samples collected. Tissue fragments were subject to immunohistochemical (rhVEGF, VEGFr, VIII factor, CD34 antibodies), ultrastructural and morphostructural investigations. The results showed that rhVEGF improved the condition of flaps and that systemic administration was effective in promoting the development of an adequate vascular network.

Supplementation with tocotrienols from Bixa orellana improves the in vivo efficacy of daptomycin against methicillin-resistant Staphylococcus aureus in a mouse model of infected wound

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of skin and soft-tissue infection worldwide. An adequate immune response acts as a first line of defence against infections and therefore plays an essential role in the maintenance of health. Tocotrienols (T3s), the lesser known isomers of vitamin E, possess many biological properties and have been recognized as immunomodulators.

PURPOSE

The aim of this study was to investigate whether the in vivo supplementation with a mixture of 87.1% δ- and 12.9% γ-T3s extract from seeds of Bixa orellana, (T3s) could be effective in increasing the effect of daptomycin (DAP) in a mouse model of wound infection due to MRSA.

STUDY DESIGN/METHODS

Bacteria were inoculated onto full-thickness wound on the dorsal side of BALB/c mice at 5 × 10⁶ CFU per mouse. Mice were randomized into five groups: an uninfected group, an infected-untreated group, a T3s-pretreated group with no antibiotics given after challenge, a T3s-pretreated group plus DAP given after challenge, a group only given DAP after challenge. Main outcome measures were: bacterial load on the wounds, analysis of Natural Killer (NK) cytotoxicity, immunological phenotype and markers of tissue repair.

RESULTS

Our results showed that bacterial load in wounds from mice receiving T3s or DAP alone was 1- or 3-log₁₀ lower, respectively, compared with the infected-untreated group. T3s plus daptomycin showed the highest efficacy, achieving a 4-log₁₀ decrease in bacterial load. This higher antimicrobial effect was associated with increased levels of NK cytotoxicity and markers of wound repair.

CONCLUSION

These data suggest that treatment with T3s may be useful for the management of infected wounds as immune adjuvants in combination with DAP.

In vitro and in vivo activity of fosfomycin alone and in combination with rifampin and tigecycline against Gram-positive cocci isolated from surgical wound infections

Complicated skin and soft tissue infections constitute a heterogeneous group of severe disorders, with surgical site infections being the most common hospital-acquired ones. The aim of our study was to investigate the synergistic and bactericidal activities of antimicrobial combinations of fosfomycin with rifampicin and tigecycline against Enterococcus faecalis, Enterococcus faecium and methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates, and also to evaluate their in vivo effects in a mouse wound infection model. In in vitro studies, the combinations of fosfomycin with rifampicin and tigecycline were both synergistic. These synergies were confirmed in in vivo studies: the drug combinations showed the highest antimicrobial effects compared to monotherapy. In conclusion, the efficacy of fosfomycin combinations, also confirmed in our in vivo model, may suggest new directions in the treatment of infected skin and a possible alternative way to control bacterial skin infection.

Increase of n-NOS and i-NOS in Rat Colon After Sacral Neuromodulation

OBJECTIVE

Sacral neuromodulation (SNM) is proposed to treat different anorectal dysfunctions but its mechanism of action is not yet known. Our previous study demonstrated how SNM can significantly increase neuronal nitric oxide synthase NOS (n-NOS) and inducible NOS (i-NOS) expression in the anus and rectum of rats. There are no reports regarding the relation between SNM and NOS in colonic cells: our aim was to assess NOS expression in colonic rat model after SNM.

MATERIALS AND METHODS

Twenty-six female Sprangue-Dawley rats were considered: group I, normal control rats; group II, sham treatment rats, in whom electrodes for electrical stimulation were placed in S1 foramen bilaterally and left in place, without performing neuromodulation; group III, rats in whom SNM was performed. After 14 days, the rats were sacrificed and we evaluated n-NOS and i-NOS in colonic specimens by immunohistochemistry and Western Blot analysis.

RESULTS

Western Blot analysis showed that levels of n-NOS and i-NOS were higher in colon of the III group rats respect to the others; in particular, immunohistochemistry revealed that, after neuromodulation, n-NOS expression in the muscle cells and i-NOS expression in glandular epithelium and nervous cells were highly represented (p < 0.05).

CONCLUSION

Our study showed that in colon, SNM is able to influence NO synthesis, activating n-NOS expression in muscle cells and i-NOS expression in glandular epithelium and nervous cells. Our study showed a complex colonic response to SNM. This experimental model could be applied to better understand the mechanism of action of SNM in bowel dysfunction.

Booster immunizations with DNA plasmids encoding HER-2/neu prevent spontaneous mammary cancer in HER-2/neu transgenic mice over life span

Cancer vaccines are less effective at old than at young age because of immunosenescence. Besides, in preliminary observations we showed that the immunization with HER-2/neu DNA plasmid in transgenic young mice (standard immunization, SI) delays but not abrogate spontaneous mammary tumours progressively appearing during aging. In this study we evaluated whether booster immunizations (BI) of HER-2/neu transgenic mice with HER-2/neu DNA plasmids every 6 (ECD6), 3 (ECD3), or 1.5 (ECD1.5) months after SI induce a protective immunity that could be maintained over life span. The long term BI significantly improved the effect of SI increasing the number of tumour free mice at 110 weeks of age from 13% (SI) to 58% (BI). Both the number and the volume of tumour masses were reduced in BI than in SI groups. The protective effect of BI was associated with increased antibody production with isotype switching to IgG2a, augmented CD4 T cells, and increased in vivo cytotoxicity of HER-2/neu specific cytotoxic T lymphocytes, mainly in ECD1.5 and ECD3 groups. The transfer of sera from ECD1.5 mice to untreated HER-2/neu mice highly protected against tumour development than sera from SI mice. We conclude that BI induce a protective immunity effective over life span.

Effect of hyperglycemia on the number of CD117+ progenitor cells and their differentiation toward endothelial progenitor cells in young and old ages

Dysfunction of endothelial progenitor cells (EPCs) has been reported either in aging or diabetes, though the influence of an "old" environment on numerical and functional changes of diabetes associated EPCs is not known. We evaluated the effect of both aging and early stage of streptozotocin-induced diabetes on the number of bone marrow-derived CD117⁺ progenitor cells, and on their differentiation in vitro toward EPCs. The phenotype of progenitor cells and the uptake of acetylated-low density lipoprotein (Ac-LDL) were evaluated after cell culture in VEGF, FGF-1, and IGF-1 supplemented medium. Hyperglycemia similarly reduced the number of CD117⁺ cells both in young and old mice. CD117⁺ cells from young mice differentiated better than those from old animals "in vitro", with a greater reduction of CD117⁺ cells and an higher increase of CD184⁺VEGFR-2⁺ cells. In diabetic mice, in vitro CD117⁺ cells differentiation was significantly reduced in young animals. Diabetes did not impact on the scarce differentiation of CD117⁺ cells from old mice. Hyperglycemia reduced the uptake of acLDL by EPCs greatly in young than in old mice. These findings indicate that part of the EPCs functional alterations induced by hyperglicemia in young mice are observed in normal aged mice.

Morpho-Structural Investigations of Biomaterials for Biocidal Activity

A new wound dressing made of gelatin and Ag, was evaluated for the management of tissue reconstitution in rats. The gelatin–based dressing, with metabolic stimulation properties that favored the recovery of the skin was made of stiff sheets to supply the repairingtissue with mechanical support. The gelatin sheets enhanced the development of collagen fibers and subsequently cell proliferation at the level of stromal and vascular elements. A protocol based on the utilization of natural biomaterials in the presence of low concentrations of a biocidal was proposed which could control microbiocidal activities principally in burned and debilitated patients.

Chitin Nanofibrils Linked to Chitosan Glycolate as Spray, Gel, and Gauze Preparations for Wound Repair

Recent advances in process chemistry have made it possible to make chitosan and chitin nanofibril materials more flexible and useful for the development of new biorelated products. In this study, the effectiveness of three chitin nanofibril/chitosan glycolate-based preparations, a spray (Chit-A), a gel (Chit-B), and a gauze (Chit-C), in healing cutaneous lesions are assessed macroscopically and by light microscopy immunohistochemistry. These evaluations are compared to the results obtained using a laser co-treatment. The wound repair provided by the three preparations is clearly evident even without the synergistic effect of the laser co-treatment. These results confirm the effectiveness of chitin nanofibril/chitosan glycolate-based products in restoring subcutaneous architecture. The spray seems to be most effective in healing superficial lesions, including extensive ones; the gel is more effective in repairing shallow lesions as well as an aesthetic factor while the gauze is effective in slow-healing dermo-epidermal wounds.

Efficacy of the Quorum Sensing Inhibitor FS10 Alone and in Combination with Tigecycline in an Animal Model of Staphylococcal Infected Wound

In staphylococci, quorum sensing regulates both biofilm formation and toxin production, moreover it has been demonstrated to be inhibited by RNAIII inhibiting peptide (RIP). Aim our study was to evaluate the in vitro activity and its in vivo efficacy of the combined administration of FS10, a novel RIP derivative, and tigecycline in an animal model of methicillin-resistant (MR) and methicillin-sensitive (MS) Staphylococcus aureus wound infection. Using a 1.x2 cm template, one full thickness wound was established through the panniculus carnosus on the back subcutaneous tissue of each animal. Infection was determined by inoculation of 5x10⁷ CFU/ml of bacteria, that produced an abscess within 24 h, after this, treatment was initiated. The study included, for each strain, a control group without infection, a control infected group that did not receive any treatment and a control infected group with drug-free foam dressing, and three infected groups treated, respectively, with: FS10-soaked foam dressing (containing 20 μg FS10), daily intraperitoneal tigecycline (7 mg/Kg), FS10-soaked foam dressing (containing 20 μg FS10) and daily intraperitoneal injections of tigecycline (7 mg/Kg). The main outcome measures were quantitative culture and histological examination of tissue repair. The highest inhibition of infection was achieved in the group that received FS10-soaked and parenteral tigecycline reducing the bacterial load from 10⁷ CFU/ml to about 10³ CFU/g for MSSA and to about 10⁴ CFU/g for MRSA. The group treated with FS10-soaked foam dressing associated with parenteral tigecycline showed, histologically, better overall healing with epithelialization and collagen scores significantly higher than those of the other groups in both strains. In conclusion, the combined use of topical FS10 with i.p. tigecycline induced positive interaction in vivo, resulting in an enhanced therapeutic benefit versus staphylococcal infections in murine wound models.

Effects of the Infusion of 4% or 20% Human Serum Albumin on the Skeletal Muscle Microcirculation in Endotoxemic Rats

Background

Sepsis-induced microcirculatory alterations contribute to tissue hypoxia and organ dysfunction. In addition to its plasma volume expanding activity, human serum albumin (HSA) has anti-oxidant and anti-inflammatory properties and may have a protective role in the microcirculation during sepsis. The concentration of HSA infused may influence these effects. We compared the microcirculatory effects of the infusion of 4% and 20% HSA in an experimental model of sepsis.

Methods

Adult male Wistar rats were equipped with arterial and venous catheters and received an intravenous infusion of lipopolysaccharide (LPS, serotype O127:B8, 10 mg/kg over 30 minutes) or vehicle (SHAM, n = 6). Two hours later, endotoxemic animals were randomized to receive 10 mL/kg of either 4% HSA (LPS+4%HSA, n = 6), 20% HSA (LPS+20%HSA, n = 6) or 0.9% NaCl (LPS+0.9%NaCl, n = 6). No fluids were given to an additional 6 animals (LPS). Vessel density and perfusion were assessed in the skeletal muscle microcirculation with sidestream dark field videomicroscopy at baseline (t0), 2 hours after LPS injection (t1), after HSA infusion (t2) and 1 hour later (t3). The mean arterial pressure (MAP) and heart rate were recorded. Serum endothelin-1 was measured at t2.

Results

MAP was stable over time in all groups. The microcirculatory parameters were significantly altered in endotoxemic animals at t1. The infusion of both 4% and 20% HSA similarly increased the perfused vessel density and blood flow velocity and decreased the flow heterogeneity to control values. Microvascular perfusion was preserved in the LPS+20%HSA group at t3, whereas alterations reappeared in the LPS+4%HSA group.

Conclusions

In a rat model of normotensive endotoxemia, the infusion of 4% or 20% HSA produced a similar acute improvement in the microvascular perfusion in otherwise unresuscitated animals.

EFFECT OF PLATELET RICH PLASMA CONCENTRATION ON SKELETAL MUSCLE REGENERATION: AN EXPERIMENTAL STUDY

Skeletal muscle injuries are common causes of severe long-term pain and physical disability, accounting for up to 55% of all sports injuries. The phases of the healing processes after direct or indirect muscle injury are complex but clearly defined and include well-coordinated steps: degeneration, inflammation, regeneration, and fibrosis. Despite this frequent occurrence and the presence of a body of data on the pathophysiology of muscle injuries, none of the current treatment strategies have shown to be really effective in strictly controlled trials. Platelet-rich plasma (PRP) is a promising alternative approach based on the ability of autologous growth factors (GFs) to accelerate tissue healing, improve muscular regeneration, increase neovascularization and reduce fibrosis. The present study is focused on the use of different concentrations of PRP as a source of GFs. Unilateral muscle lesions were created on the longissimus dorsi muscle of Wistar rats. Twenty-four h after surgical trauma, the lesion was filled with an intramuscular injection of PRP at 2 different concentrations. A group of rats were left untreated (controls). Animals were sacrificed at 3, 15 and 60 days from surgery. Histological, immunohistochemical and histomorphometric analyses were performed to evaluate muscle regeneration, neovascularization, fibrosis and inflammation. The PRP-treated muscles showed better muscle regeneration, more neovascularization and a slight reduction of fibrosis compared with the control muscles in a dose dependent manner. However, further studies also assessing pain and functional recovery are scheduled.

Identification and characterization of cancer stem cells from head and neck squamous cell carcinoma cell lines

BACKGROUND/AIMS

Head and neck squamous cell carcinoma (HNSCC) ranks sixth worldwide for tumor-related mortality. A subpopulation of tumor cells, termed cancer stem cells (CSCs), has the ability to support cancer growth. Therefore, profiling CSC-enriched populations could be a reliable tool to study cancer biology.

METHODS

We performed phenotypic characterization of 7 HNSCC cell lines and evaluated the presence of CSCs. CSCs from Hep-2 cell line and HNSCC primary cultures were enriched through sphere formation and sphere-forming cells have been characterized both in vitro and in vivo. In addition, we investigated the expression levels of Nicotinamide N-methyltransferase (NNMT), an enzyme overexpressed in several malignancies.

RESULTS

CSC markers were markedly expressed in Hep-2 cell line, which was found to be highly tumorigenic. CSC-enriched populations displayed increased expression of CSC markers and a strong capability to form tumors in vivo. We also found an overexpression of CSC markers in tumor formed by CSC-enriched populations. Interestingly, NNMT levels were significantly higher in CSC-enriched populations compared with parental cells.

CONCLUSION

Our study provides an useful procedure for CSC identification and enrichment in HNSCC. Moreover, results obtained seem to suggest that CSCs may represent a promising target for an anticancer therapy.

In vitro activity and in vivo animal model efficacy of IB-367 alone and in combination with imipenem and colistin against Gram-negative bacteria

The aim of our study was to evaluate the in vitro activity of IB-367 and its bactericidal effect for Pseudomonas aeruginosa and Escherichia coli, associated to a synergic study to test the antibiotic combinations between the peptide and colistin or imipenem. Minimum inhibitory concentrations (MICs), the minimum bactericidal concentrations (MBCs), the synergy test and killing study were carried out to evaluate the IB-367 activity. In the in vivo model, a wound was incised through the panniculus carnosus of BALB/c mice, and then inoculated with 5 × 107 colony-forming units of P. aeruginosa and E. coli. For each strain, the study included an infected or not infected group that did not receive any treatment, and five contaminated groups treated with local IB- 367, intraperitoneal imipenem, intraperitoneal colistin, topical IB-367 local plus intraperitoneal imipenem or intraperitoneal colistin. All isolates were inhibited by IB-367 at concentrations of 4-64 mg/l. Killing by IB-367 was shown to be very rapid: its activity on all Gram-negative bacteria was completed within a 40 min exposure period at a concentration of 2 × MIC/l. Synergy was demonstrated when IB-367 was combined with colistin or imipenem. In in vivo studies, the groups treated with topical IB-367 and intraperitoneal colistin showed the best results in terms of bacterial load inhibition either for Pseudomonas or for E. coli. The good in vitro activity and in vivo efficacy, as well as, the synergic interactions with antibiotics suggest that IB-367 is a promising candidate for potential application in the treatment of wound Gram-negative infections.

In vitro and in vivo effects of sub-MICs of pexiganan and imipenem on Pseudomonas aeruginosa adhesion and biofilm development

An in vitro and in vivo study was performed to quantify adhesion and biofilm formation ability of Pseudomonas aeruginosa slime producer under the effect of sub-minimal inhibitory concentrations (MICs) of pexiganan and imipenem. To evaluate adherence, squares of ureteral stents were placed in six-well tissue-culture plates containing 6 ml of a cell suspension grown in the presence of sub-MICs of study antibiotics. To evaluate biofilm formation sterilized squares were placed in six-well tissue culture plates containing 6 ml of triptic soy broth (TSB) supplemented with 0.25% of glucose and the respective amount of antibiotic. For in vivo study a biofilm infection rat model was performed. The study included an uninfected control group to evaluate the sterility of surgical procedure, a group infected with a slime-producer P. aeruginosa strain not previously treated with antibiotics and two groups infected with the strain previously treated with imipenem or pexiganan. Adherence and biofilm in vitro formation was strongly affected by pre-treatment with pexiganan and imipenem, with the latter being the more effective antibiotic. The in vivo results showed a reduction in bacterial load on the ureteral stent tissue of the pre-treated strain. Differently, urine cultures showed no differences in bacterial growth for the pre-treated strain showing that it retained its ability to cause infection. This study suggests that sub-MIC imipenem and pexiganan could be a good strategy to target the adhesion process during the infection cycle.

IB-367 pre-treatment improves the in vivo efficacy of teicoplanin and daptomycin in an animal model of wounds infected with meticillin-resistant Staphylococcus aureus

Antimicrobial peptides are known as immunomodulators and antibiotic enhancers. We report that administration of an antimicrobial peptide, IB-367, was efficacious in increasing the antimicrobial activity of daptomycin and teicoplanin in a mouse model of wound infection caused by meticillin-resistant Staphylococcus aureus (MRSA). Mice were assigned to seven groups: an IB-367 pre-treated group with no antibiotics given after challenge, two IB-367 pre-treated groups plus daptomycin or teicoplanin given after challenge, two groups treated with daptomycin or teicoplanin only after challenge, and two control groups without infection or that did not receive any treatment. The main outcome measures were quantitative bacterial culture and analysis of natural killer (NK) cytotoxicity and leukocyte phenotype. The wound, established through the panniculus carnosus muscle of mice, was infected by MRSA. Bacterial cultures of mice receiving antibiotics alone showed a −2 log decrease, whilst those for IB-367 plus daptomycin or teicoplanin showed a −4 log decrease. IB-367 plus daptomycin showed the highest efficacy. The higher antimicrobial effect exerted by IB-367 was associated with increased levels of NK cytotoxicity but not of NK cell number. IB-367 increased the number of both CD11b and Gr-1 cells 3 days after MRSA challenge, whereas both of these leukocyte populations were reduced at 10 days after challenge. Our data suggest that a combination of IB-367 with antibiotic exerts a therapeutic effect and may be useful for the management of staphylococcal wounds.

Takotsubo cardiomyopathy: real life management in the intensive coronary care unit

AIM

Takotsubo cardiomyopathy is a cardiac syndrome characterized by reversible left ventricular dysfunction, ischemic changes on electrocardiogram, elevation of cardiac biomarkers, absence of obstructive coronary artery disease in the setting of various stressing conditions. To date, little is known on best clinical management of this syndrome in coronary care units. Whe thus aimed to present our experience in a real life takotsubo population.

METHODS

We identified all patients with Takotsubo cardiomyopathy at our center Maria Vittoria Hospital, Turin, between October 2006 and February 2012. Patients where considered to have Takotsubo syndrome if they presented chest pain on admission, new elettrocardiographic changes suggestive of myocardial ischemia, evidence of apical balloning with hyperkinesis of basal segments on echocardiography, rise in troponin I and, after coronary angiography, no coronary artery disease. We adjudicated the following clinical events: death and recurrence of ischemic events; we also made a detailed analysis of the stressing conditions leading to clinical syndrome.

RESULTS

A total of 26 patients were included, 4 (15%) males and 22 (85%) females; mean age was 71±13. After more than 1 year median follow-up the incidence of death was 7.7% (2 deaths), with all deaths, due to cardiogenic shock, occurring in the first 10 days of hospitalization; 2 patients (8%) experienced recurrence of ischemic event. Leading cause of Takostubo was major depressive episode (16%), followed by mourning (12%), falling down with difficulties in standing up (12%), vomiting (8%) and pulmonary infection (8%). In the coronary care unit major complications of patients with Takotsubo syndrome were acute hearth failure (62%), cardiogenic shock (27%), sepsis (31%), pulmonary aedema (27%) and anemia (12%). Two patients needed non-invasive ventilation support and one intra-aortic balloon conterpulasation. In addition one patient developed rabdomyolysis and one left heart thrombus. Cornerstone drug therapy was as follows: 96% of patients took aspirin, 58% beta blockers, 54% nitroglicerine, 46% intravenous heparin, 27% dopamine.

CONCLUSION

Takotsubo syndrome is an important safety issue occurring predominantly in post-menopausal women undergoing specific stressing condition. Heart failure and cardiogenic shock are the most serious clinical complication and leading cause of death in the short period, good prognosis is seen thereafter.

The efficacy of the quorum sensing inhibitor FS8 and tigecycline in preventing prosthesis biofilm in an animal model of staphylococcal infection

We investigated the efficacy of tigecycline and FS8, alone or combined, in preventing prosthesis biofilm in a rat model of staphylococcal vascular graft infection. Graft infections were established in the back subcutaneous tissue of adult male Wistar rats by implantation of Dacron prostheses followed by topical inoculation with 2 × 10⁷ colony-forming units of Staphylococcus aureus, strain Smith diffuse. The study included a control group, a contaminated group that did not receive any antibiotic prophylaxis, and three contaminated groups that received: (i) intraperitoneal tigecycline, (ii) FS8-soaked graft, and (iii) tigecycline plus FS8-soaked graft, respectively. Each group included 15 animals. The infection burden was evaluated by using sonication and quantitative agar culture. Moreover, an in vitro binding-study was performed to quantify the how much FS8 was coated to the surface of the prosthesis. Tigecycline, combined with FS8, against the adherent bacteria showed MICs (2.00 mg/L) and MBCs (4.00 mg/L) four-fold lower with respect to tigecycline alone in in vitro studies. The rat groups treated with tigecycline showed the lowest bacterial numbers (4.4 × 10⁴ ± 1.2 × 10⁴ CFU/mL). The FS8-treated group showed a good activity and significant differences compared to control group with bacterial numbers of 6.8 × 10⁴ ± 2.0 × 10⁴ CFU/mL. A stronger inhibition of bacterial growth was observed in rats treated with a combined FS8 and tigecycline therapy than in those that were singly treated with bacterial numbers of 10¹ CFU/mL graft. In conclusion, the ability to affect biofilm formation as well, its property to be an antibiotic enhancer suggests FS8 as alternative or additional agent to use in conjunction with conventional antimicrobial for prevention of staphylococcal biofilm related infection.

Effect of annatto-tocotrienols supplementation on the development of mammary tumors in HER-2/neu transgenic mice

Tocotrienols (T3), the lesser known isomers of vitamin E, have been reported to possess anticancer activity both in in vitro and in vivo experimental models of rodents transplanted with parental tumors or treated with carcinogens. We investigated the effects of dietary supplementation with annatto-T3 (90% δ-T3 and 10% γ-T3) on the spontaneous development of mammary tumors in HER-2/neu transgenic mice. Underlying mechanisms of the antitumor effect were evaluated by studying apoptosis, senescent-like growth arrest, immune modulation, oxidative effect and the expression of HER-2/neu in tumoral mammary glands of transgenic mice and in vitro in human and mice tumor cell lines. Annatto-T3 supplementation delayed the development of mammary tumors, reducing the number and size of mammary tumor masses and those of lung metastases. In annatto-T3-supplemented mice, both apoptosis and senescent-like growth arrest of tumor cells were increased in mammary glands while no immune modulation was observed. In vitro, a dose-dependent inhibition of cell growth, increased apoptosis and senescent-like growth arrest and a time-dependent accumulation of reactive oxygen species were observed in tumor cells treated with annatto-T3 or purified δ-T3. Annatto-T3 reduced both HER-2/neu mRNA and p185(HER-2/neu) protein in tumors and in tumor cell lines. The results show that the antitumor effect of annatto-T3 supplementation in HER-2/neu transgenic mice is mainly related to the direct induction of oxidative stress, senescent-like growth arrest and apoptosis of tumor cells rather than to an immune modulation.