Inhibition of 7α,26-dihydroxycholesterol biosynthesis promotes midbrain dopaminergic neuron development.

Dysregulated cholesterol metabolism has been linked to neurodegeneration. We previously found that free, non-esterified, 7α,(25R)26-dihydroxycholesterol (7α,26-diHC), was significantly elevated in the cerebrospinal fluid of patients with Parkinson's disease (PD). In this study we investigated the role of 7α,26-diHC in midbrain dopamine (mDA) neuron development and survival. We report that 7α,26-diHC induces apoptosis and reduces the number of mDA neurons in hESC-derived cultures and in mouse progenitor cultures. Voriconazole, an oxysterol 7α-hydroxylase (CYP7B1) inhibitor, increases the number of mDA neurons and prevents the loss of mDA neurons induced by 7α,26-diHC. These effects are specific since neither 7α,26-diHC nor voriconazole alter the number of Islet1+ oculomotor neurons. Furthermore, our results suggest that elevated 24(S),25-epoxycholesterol, which has been shown to promote mDA neurogenesis, may be partially responsible for the effect of voriconazole on mDA neurons. These findings suggest that voriconazole, and/or other azole CYP7B1 inhibitors may have implications in PD therapy development.

Toward personalized immunotherapy in sepsis: The PROVIDE randomized clinical trial.

The state of immune activation may guide targeted immunotherapy in sepsis. In a double-blind, double-dummy randomized clinical study, 240 patients with sepsis due to lung infection, bacteremia, or acute cholangitis were subjected to measurements of serum ferritin and HLA-DR/CD14. Patients with macrophage activation-like syndrome (MALS) or immunoparalysis were randomized to treatment with anakinra or recombinant interferon-gamma or placebo. Twenty-eight-day mortality was the primary endpoint; sepsis immune classification was the secondary endpoint. Using ferritin >4,420 ng/mL and <5,000 HLA-DR receptors/monocytes as biomarkers, patients were classified into MALS (20.0%), immunoparalysis (42.9%), and intermediate (37.1%). Mortality was 79.1%, 66.9%, and 41.6%, respectively. Survival after 7 days with SOFA score decrease was achieved in 42.9% of patients of the immunotherapy arm and 10.0% of the placebo arm (p = 0.042). Three independent immune classification strata are recognized in sepsis. MALS and immunoparalysis are proposed as stratification for personalized adjuvant immunotherapy. Clinicaltrials.gov registration NCT03332225.

Effect of intravenous clarithromycin in patients with sepsis, respiratory and multiple organ dysfunction syndrome: a randomized clinical trial.

BACKGROUND: Clarithromycin may act as immune-regulating treatment in sepsis and acute respiratory dysfunction syndrome. However, clinical evidence remains inconclusive. We aimed to evaluate whether clarithromycin improves 28-day mortality among patients with sepsis, respiratory and multiple organ dysfunction syndrome. METHODS: We conducted a multicenter, randomized, clinical trial in patients with sepsis. Participants with ratio of partial oxygen pressure to fraction of inspired oxygen less than 200 and more than 3 SOFA points from systems other than the respiratory function were enrolled between December 2017 and September 2019. Patients were randomized to receive 1 gr of clarithromycin or placebo intravenously once daily for 4 consecutive days. The primary endpoint was 28-day all-cause mortality. Secondary outcomes were 90-day mortality; sepsis response (defined as at least 25% decrease in SOFA score by day 7); sepsis recurrence; and differences in peripheral blood cell populations and leukocyte transcriptomics. RESULTS: Fifty-five patients were allocated to each arm. By day 28, 27 (49.1%) patients in the clarithromycin and 25 (45.5%) in the placebo group died (risk difference 3.6% [95% confidence interval (CI) - 15.7 to 22.7]; P = 0.703, adjusted OR 1.03 [95%CI 0.35-3.06]; P = 0.959). There were no statistical differences in 90-day mortality and sepsis response. Clarithromycin was associated with lower incidence of sepsis recurrence (OR 0.21 [95%CI 0.06-0.68]; P = 0.012); significant increase in monocyte HLA-DR expression; expansion of non-classical monocytes; and upregulation of genes involved in cholesterol homeostasis. Serious and non-serious adverse events were equally distributed. CONCLUSIONS: Clarithromycin did not reduce mortality among patients with sepsis with respiratory and multiple organ dysfunction. Clarithromycin was associated with lower sepsis recurrence, possibly through a mechanism of immune restoration. Clinical trial registration clinicaltrials.gov identifier NCT03345992 registered 17 November 2017; EudraCT 2017-001056-55.

A four-probiotic preparation for ventilator-associated pneumonia in multi-trauma patients: results of a randomized clinical trial.

The role of probiotics in the prevention of ventilator-associated pneumonia (VAP) remains inconclusive. The aim of this study was to assess the efficacy of a probiotic regimen for VAP prophylaxis in mechanically ventilated multi-trauma patients, intubated immediately after the injurious insult. In a randomized, placebo-controlled study enrolling multi-trauma patients, patients expected to require mechanical ventilation for >10 days were assigned at random to receive prophylaxis with a probiotic formula (n=59) or placebo (n=53). The probiotic formula was a preparation of Lactobacillus acidophilus LA-5 [1.75 × 109 colony-forming units (cfu)], Lactobacillus plantarum (0.5 × 109 cfu), Bifidobacterium lactis BB-12 (1.75 × 109 cfu) and Saccharomyces boulardii (1.5 × 109 cfu) in sachets. Each patient received two sachets twice daily for 15 days: one through the nasogastric tube and one spread on the oropharynx. The incidence of VAP was the primary endpoint. The incidence of other infections and sepsis, and the duration of hospital stay were the secondary endpoints. Administration of probiotics reduced the incidence of VAP [11.9% vs 28.3%, hazard ratio (HR) 0.34, 95% confidence interval (CI) 0.13-0.92; P=0.034] and sepsis [6.8% vs 24.5%, odds ratio 0.22, 95% CI 0.07-0.74: P=0.016]. Furthermore, probiotic prophylaxis reduced the time of stay in the intensive care unit (ICU) and the length of hospital stay. The prophylactic use of probiotics with a combination of enteral and topical application to the oropharynx had a positive effect on the incidence of VAP and sepsis, as well as on ICU and total hospital stay in patients receiving protracted mechanical ventilation.

Second dose of the BNT162b2 mRNA vaccine: Value of timely administration but questionable necessity among the seropositive.

This study monitored titers of neutralizing IgG against the receptor-binding domain of the SARS-CoV-2 S1 subunit 14 days post-injection of each dose of the BNT162b2 mRNA Covid-19 vaccine in 401 Greek healthcare workers aged 20-67. After the first dose, titers varied upon age and history of infection, being lower in the 50+ age group and significantly higher among the seropositive. After the second dose, immunogenicity was significantly boosted in the age 50+ and SARS-CoV-2-naïve individuals, indicating the effectuality of its timely administration, yet questioning its value among the seropositive.

Use of IFNγ/IL10 Ratio for Stratification of Hydrocortisone Therapy in Patients With Septic Shock.

Large clinical trials testing hydrocortisone therapy in septic shock have produced conflicting results. Subgroups may benefit of hydrocortisone treatment depending on their individual immune response. We performed an exploratory analysis of the database from the international randomized controlled clinical trial Corticosteroid Therapy of Septic Shock (CORTICUS) employing machine learning to a panel of 137 variables collected from the Berlin subcohort comprising 83 patients including demographic and clinical measures, organ failure scores, leukocyte counts and levels of circulating cytokines. The identified theranostic marker was validated against data from a cohort of the Hellenic Sepsis Study Group (HSSG) (n = 246), patients enrolled in the clinical trial of Sodium Selenite and Procalcitonin Guided Antimicrobial Therapy in Severe Sepsis (SISPCT, n = 118), and another, smaller clinical trial (Crossover study, n = 20). In addition, in vitro blood culture experiments and in vivo experiments in mouse models were performed to assess biological plausibility. A low serum IFNγ/IL10 ratio predicted increased survival in the hydrocortisone group whereas a high ratio predicted better survival in the placebo group. Using this marker for a decision rule, we applied it to three validation sets and observed the same trend. Experimental studies in vitro revealed that IFNγ/IL10 was negatively associated with the load of (heat inactivated) pathogens in spiked human blood and in septic mouse models. Accordingly, an in silico analysis of published IFNγ and IL10 values in bacteremic and non-bacteremic patients with the Systemic Inflammatory Response Syndrome supported this association between the ratio and pathogen burden. We propose IFNγ/IL10 as a molecular marker supporting the decision to administer hydrocortisone to patients in septic shock. Prospective clinical studies are necessary and standard operating procedures need to be implemented, particularly to define a generic threshold. If confirmed, IFNγ/IL10 may become a suitable theranostic marker for an urging clinical need.

Spread of NDM-producing Klebsiella pneumoniae in a tertiary Greek hospital.

Bacterial carbapenem resistance, especially when mediated by transferable carbapenemases, is of important public health concern. An increased number of metallo-ß-lactamase (MBL)-producing Klebsiella pneumoniae strains isolated in a tertiary hospital in Thessaloniki, Greece, called for further genetic investigation.The study included 29 non-repetitive carbapenem resistant K. pneumoniae isolates phenotypically characterized as MBL-producers collected in a tertiary hospital in Greece. The isolates were screened for the detection of carbapenemase genes (K. pneumoniae carbapenemase (blaKPC), Verona-integron-encoded MBL-1 (blaVIM-1), imipenemase (blaIMP), oxacillinase-48 (blaOXA-48) and New Delhi MBL (blaNDM)). The genetic relationship of the isolates was determined by Random Amplified Polymorphic DNA (RAPD) analysis. The whole genome sequences (WGS) from two NDM-positive K. pneumoniae isolates were further characterized.The presence of New Delhi MBL (blaNDM) gene was confirmed in all K. pneumoniae isolates, while blaKPC and blaVIM-1 genes were co-detected in one and two isolates, respectively. The RAPD analysis showed that the isolates were clustered into two groups. The whole genome sequence analysis of two K. pneumoniae isolates revealed that they belonged to the sequence type 11, they carried the blaNDM-1 gene, and exhibited differences in the number and type of the plasmids and the resistant genes.All MBL-producing K. pneumoniae isolates of the study harbored a blaNDM gene, while WGS analysis revealed genetic diversity in resistance genes. Continuous surveillance is needed to detect the emergence of new clones in a hospital setting, while application of antimicrobial stewardship is the only way to reduce the spread of multi-resistant bacteria.

Past history of stage I/II solid tumor malignancy impacts considerably on sepsis mortality: a propensity score matching analysis from the hellenic sepsis study group.

BACKGROUND: Whether past history of solid stage I/II inactive cancer has an impact on 28-day mortality of sepsis remains unclear. We aimed to determine the impact of history of stage I or II solid tumor malignancy in complete remission the last 3 years on sepsis outcome. METHODS: Using the database of the Hellenic Sepsis Study Group from 1553 patients with sepsis admitted in the ICU, 83 patients with sepsis by Sepsis-3 definition with past-history of stage I/II inactive solid malignancy the last 3 years were depicted. A comparator group of 83 patients fully matched for age, severity, type of infection and comorbidities was selected by propensity score matching. RESULTS: Mortality after 28 days was 37.3% in the comparator group and 54.2% in the solid tumor stage I/II group (odds ratio for death 1.98; p: 0.030). Following step-wise forward Cox regression analysis, septic shock (hazard ratio 1.80), acute renal injury (hazard ratio 2.06), history of coronary heart disease (hazard ratio 0.36) and history of stage I/II solid tumor malignancy (hazard ratio 1.79) were the only independent variables associated with 28-day mortality. Serum levels of procalcitonin and of soluble urokinase plasminogen activator receptor were similar between the two groups of comparisons. CONCLUSIONS: Past history of stage I/II solid malignancy is an independent risk factor for unfavorable outcome from sepsis the first 28 days.

Susceptibility profiles and clinical efficacy of antifungals against candida bloodstream isolates from critically ill patients: Focus on intravenous itraconazole.

In vitro and clinical data were analysed to evaluate the susceptibility profile of itraconazole in light of the new cut-off points. The in vitro activity of itraconazole was compared with that of eight comparators against 119 Candida bloodstream isolates from 2015 to 2018. Minimum inhibitory concentrations (MICs) were measured by the colorimetric MICRONAUT-S assay. The content of wells without any color change was sub-cultured to measure killing efficacy. No major differences were found against Candida albicans. Itraconazole, posaconazole and amphotericin B were the most active agents against Candida parapsilosis. Of the 32 isolates of C. parapsilosis that were resistant to fluconazole, 96.9%, 78.1% and 93.8% were susceptible to itraconazole, voriconazole and posaconazole, respectively. The ratio of the minimum fungicidal concentration (MFC) to the MIC of itraconazole was lower than for the other azoles against C. parapsilosis and C. glabrata. Itraconazole achieved greater inhibition over-time of the growth of C. parapsilosis than fluconazole. Seventy-three critically ill patients who were unresponsive to antibiotics received intravenous empirical treatment with itraconazole (n = 28) or comparators (n = 45). Case-control matching was conducted for severity, comorbidities, risk factors for candidemia, administered antibiotics and days of antifungal treatment. Breakthrough candidemia was found in 3.6% of patients treated with itraconazole and in 32.1% of patients treated with comparators (P: 0.020); breakthrough candidemia by C. parapsilosis was found in 3.6% and 28.6% of patients, respectively. Results indicate that itraconazole retains a valuable susceptibility profile against Candida isolates, particularly C. parapsilosis. This superior profile may explain the clinical efficacy in the occurrence of breakthrough candidemia and warrants further clinical investigation.

The clinical significance of carbapenem-resistant Klebsiella pneumoniae rectal colonization in critically ill patients: from colonization to bloodstream infection.

PURPOSE: To highlight the clinical significance of carbapenem-resistant Klebsiella pneumoniae (CRKP) rectal colonization by examining the risk factors for CRKP rectal colonization and subsequent bloodstream infection (BSI) in critically ill patients. METHODOLOGY: Prospective study of CRKP rectal colonization in an intensive care unit (ICU) during a 39-month period. CRKP strains isolated from both the blood cultures and corresponding rectal specimens (n=96) of patients were screened by PCR for the presence of antibiotic resistance-associated genes. Molecular analyses were conducted to investigate the clonal relatedness of CRKP strains from the rectal and blood specimens. RESULTS: Among the 498 patients, 226 were rectally colonized by CRKP, 48 of whom developed a CRKP BSI. The median time from hospital admission to the detection of CRKP rectal colonization was 8 days, while the median time from colonization to BSI was 4 days. The duration of ICU stay, patient/nurse ratio and prior use of antianaerobic antimicrobials were associated with CRKP rectal colonization. No specific factor was associated with BSIs in the colonized patients. The blaKPC-2 gene was detected in all 96 strains, which were all classified as sequence type ST-258. Representative pairs (n=48) of CRKP strains colonizing and infecting the same patient shared the same pulsotype. CONCLUSION: Our results indicate that hospitalized patients become infected with their colonizing strains, supporting the strong association between colonization and BSI. Limiting antianaerobic antimicrobial administration, reducing the duration of ICU stay and maintaining a low patient/nurse ratio are possible strategies to restrict rectal CRKP colonization in ICUs.

Prevalence and determinants of current and secondhand smoking in Greece: results from the Global Adult Tobacco Survey (GATS) study.

OBJECTIVES: Greece is one of the leading tobacco-producing countries in European Union, and every year over 19 000 Greeks die from tobacco-attributable diseases. The aim of the present study was to provide nationally representative estimates on current and secondhand smoking prevalence in Greece and their determinants. DESIGN: Cross-sectional. SETTING: Greece. PARTICIPANTS: A total of 4359 individuals participated in the Global Adult Tobacco Survey (GATS), a household survey of adults ≥15 years old (overall response rate 69%). They were selected through a multistage geographically clustered sampling design with face-to-face interview. PRIMARY AND SECONDARY OUTCOME MEASURES: In 2013, we investigated the prevalence of current and secondhand smoking and their determinants. Univariate and logistic regression analysis was used in order to identify possible risk factors associated with the prevalence of current and secondhand smoking. RESULTS: The prevalence of current smoking was 38.2% (95% CI 35.7% to 40.8%), and the mean number of cigarettes smoked per day was 19.8. Multivariate analysis confirmed that male gender (OR=3.24; 95% CI 2.62 to 4.00), age groups (25-39, OR=4.49; 95% CI 3.09 to 8.46 and 40-54, OR=3.51; 95% CI 1.88 to 5.87) and high school education (OR=1.97; 95% CI 1.41 to 2.74) were independently associated with the current smoking. Remarkably, responders with primary or less education had the lowest prevalence of current smoking (p<0.001). The prevalence of exposure to secondhand smoke at work, home and restaurants, was 52.3%, 65.7% and 72.2%. In total, 90.0% (95% CI 87.8% to 91.9%) of Greek population is exposed to tobacco smoke (current smoking and secondhand smoke). CONCLUSIONS: Our results revealed an extremely high prevalence of current smoking and exposure to secondhand smoke among the adult population and a positive gradient between education and current smoking. These findings are alarming and implementation of comprehensive tobacco control and prevention strategies could be impactful in fighting the tobacco epidemic in Greece.

Sense of Coherence (SOC) in Christian Orthodox Monks and Nuns in Greece.

This paper aims to investigate the stress management skills of Christian Orthodox monks and nuns, as measured by Antonovsky's scale sense of coherence (SOC). A case-control study was designed to test the hypotheses whether monks and nuns have higher SOC than secular people. The study population consisted of 193 individuals, 96 monks and nuns (study group) and 97 secular men and women (control group). SOC score was higher in monks and nuns as compared to the secular population (p = 0.002), men as compared to women (p = 0.012) and persons of older age (p = 0.004) as compared to younger individuals.

Salutogenesis and the Monks of Athos, Greece: A Spiritual Health Promotion?

Context • A cohort of studies on secular populations has indicated the role that religiosity plays in psychological well-being. An increase in the participation in religious activity has been shown to have a positive correlation with beneficial mental health outcomes. Internationally, few studies exist regarding the sense of coherence (SOC) of monks. SOC is a health asset related to stress management skills. Objective • The study aimed to assess the SOC of monks who lived at Mount Athos, Greece, and to determine its correlation with demographic characteristics. Design • The type of design was a descriptive cross-sectional study using convenience sampling. Setting • The study took place at Mount Athos in 2 monasteries and 1 skete, which is an organized community that consists of several monastic huts that belong to a communal monastery. Participants • Of the 215 monks living in the 2 monasteries and the skete, 166 monks participated. Outcome Measures • Data were collected from May-August 2012, using a structured questionnaire that was divided into 2 parts: (1) a demographic section (8 items) and (2) the Sense of Coherence (SOC-13) survey. Results • The mean age of participants was 45.5 y ± 13.0. Of the 166 monks participating, 139 (83.7 %) lived in communal monasteries, and the mean time of participation in monasticism was 18.4 ± 12.1 y. The mean value on the SOC-13 scale was 65.7 ± 6.5. According to the multiple regression analyses, the number of years in monasticism presented a positive correlation with the SOC score (ß = 0.12, SE = 0.04, P = .003), whereas the number of daily hours of sleep presented a negative correlation with the SOC score (ß = -1.34, SE = 0.50, P = .008). Conclusions • The monks seemed to have a strong SOC and, therefore, adequate stress management skills. Religious spirituality may help individuals in coping with daily life. More evidence-based studies need to be implemented to highlight the correlation between Orthodox Christian monasticism and SOC.

Placental stem cells.

The placenta represents a reservoir of progenitor, stem cells and epithelial cells that have been shown to differentiate into various types, including adipogenic, osteogenic, myogenic, hepatogenic, cardiac, pancreatic, endothelial, pulmonary and neurogenic lineages. This review focuses on the properties of placenta-derived cells, and it evaluates their current therapeutic applications in regenerative medicine and cell transplantations. Ongoing clinical and preclinical studies are investigating the safety and efficacy of the human amniotic epithelial cells (hAECs), human amniotic mesenchymal stromal cells (hAMSCs) and chorionic mesenchymal stromal cells (hCMSCs). The establishment of biobanks for placental stem cells will enable the translation of scientific research into the clinic. The advantage of the placenta as a cellular source is that it contains different cell lineages, such as the haematopoietic lineage that originates from the chorion, allantois and yolk sac, and the mesenchymal lineage that originates from the chorion and amnion. In this review, we address advances in placental stem cell characterization, and we explore their possible uses in cell therapy.

Awareness and Current Use of Electronic Cigarettes in Indonesia, Malaysia, Qatar, and Greece: Findings From 2011-2013 Global Adult Tobacco Surveys.

INTRODUCTION: Increases in electronic cigarette (e-cigarette) awareness and current use have been documented in high income countries but less is known about middle and low income countries. METHODS: Nationally representative household survey data from the first four Global Adult Tobacco Surveys to assess e-cigarettes were analyzed, including Indonesia (2011), Malaysia (2011), Qatar (2013), and Greece (2013). Correlates of e-cigarette awareness and current use were calculated. Sample sizes for Greece and Qatar allowed for further analysis of e-cigarette users. RESULTS: Awareness of e-cigarettes was 10.9% in Indonesia, 21.0% in Malaysia, 49.0% in Qatar, and 88.5% in Greece. In all four countries, awareness was higher among male, younger, more educated, and wealthier respondents. Current e-cigarette use among those aware of e-cigarettes was 3.9% in Malaysia, 2.5% in Indonesia, 2.2% in Greece and 1.8% in Qatar. Across these four countries, an estimated 818 500 people are currently using e-cigarettes. Among current e-cigarette users, 64.4% in Greece and 84.1% in Qatar also smoked cigarettes, and, 10.6% in Greece and 6.0% in Qatar were never-smokers. CONCLUSIONS: E-cigarette awareness and use was evident in all four countries. Ongoing surveillance and monitoring of awareness and use of e-cigarettes in these and other countries could help inform tobacco control policies and public health interventions. Future surveillance should monitor use of e-cigarettes among current smokers and uptake among never-smokers and relapsing former smokers.

Blood Pressure and Heart Rate Alterations through Music in Patients Undergoing Cataract Surgery in Greece.

INTRODUCTION: Music has been proposed as a safe, inexpensive, nonpharmacological antistress intervention. The purpose of this study was to determine whether patients undergoing cataract surgery while listening to meditation music experience lower levels of blood pressure and heart rate. METHODS: Two hundred individuals undergoing cataract surgery participated in the study. Hundred individuals listened to meditation music, through headphones, before and during the operation (intervention group) and 100 individuals received standard care (control group). Patients stress coping skills were measured by the Sense of Coherence Scale (SOC Scale). Systolic and diastolic blood pressure and heart rate were defined as outcome measures. RESULTS: According to the SOC Scale, both groups had similar stress coping skills (mean score: 127.6 for the intervention group and 127.3 for the control group). Before entering the operating room (OR) as well as during surgery the rise in systolic and diastolic pressures was significantly lower in the intervention group (P < 0.001). Among patients receiving antihypertensive therapy, those in the intervention group presented a lower increase only in systolic pressure (P < 0.001) at both time recordings. For those patients in the intervention group who did not receive antihypertensive treatment, lower systolic blood pressure at both time recordings was recorded (P < 0.001) while lower diastolic pressure was observed only during entry to the OR (P = 0.021). Heart rate was not altered between the two groups in any of the recordings. CONCLUSIONS: Meditation music influenced patients' preoperative stress with regard to systolic blood pressure. This kind of music can be used as an alternative or complementary method for blood pressure stabilizing in patients undergoing cataract surgery.

Characteristics, risk factors and outcomes of carbapenem-resistant Klebsiella pneumoniae infections in the intensive care unit.

OBJECTIVE: To study the characteristics, risk factors and outcomes of intensive care unit (ICU) patients with carbapenem-resistant (CRKp) and carbapenem-susceptible (CSKp) Klebsiella pneumoniae infections. METHODS: A retrospective cohort of patients with K. pneumoniae infections in an eight-bed ICU between January 2006 and October 2009. RESULTS: During the study period, 104 patients were diagnosed with K. pneumoniae infection (80 CRKp and 24 CSKp). Isolation of CRKp increased gradually during the study period, while isolation of CSKp remained constant. The mean age of patients was 66.3 ± 14.3 years. The mean APACHE II score was 17.9 ± 6.9. The median duration of ICU stay until the infection was 15 days. Thirty five patients (33.7%) had primary and 30 (28.8%) had secondary bacteremia. Seventy-two patients (69.2%) died in the ICU. No independent risk factors for development of CRKp infections were identified in the multivariate analysis. Treatment failure (p = 0.001) was the only independent predictor of mortality in the multivariate analysis (APACHE II, shock, multi-organ failure, respiratory failure, acute renal failure, acidosis and extensive-drug resistance were included in the model). No difference in mortality was found between patients with CRKp and CSKp isolates. CONCLUSIONS: Infection due to K. pneumoniae in the ICU was associated with high mortality. Control of the infection was the most important determinant of the outcome of critically ill patients.

Enzymatically cross-linked injectable alginate-g-pyrrole hydrogels for neovascularization.

Microparticles capable of releasing protein drugs are often incorporated into injectable hydrogels to minimize their displacement at an implantation site, reduce initial drug burst, and further control drug release rates over a broader range. However, there is still a need to develop methods for releasing drug molecules over extended periods of time, in order to sustain the bioactivity of drug molecules at an implantation site. In this study, we hypothesized that a hydrogel formed through the cross-linking of pyrrole units linked to a hydrophilic polymer would release protein drugs in a more sustained manner, because of an enhanced association between cross-linked pyrrole groups and the drug molecules. To examine this hypothesis, we prepared hydrogels of alginate substituted with pyrrole groups, alginate-g-pyrrole, through a horse-radish peroxidase (HRP)-activated cross-linking of the pyrrole groups. The hydrogels were encapsulated with poly(lactic-co-glycolic acid) (PLGA) microparticles loaded with vascular endothelial growth factor (VEGF). The resulting hydrogel system released VEGF in a more sustained manner than Ca(2+) alginate or Ca(2+) alginate-g-pyrrole gel systems. Finally, implantations of the VEGF-releasing HRP-activated alginate-g-pyrrole hydrogel system on chicken chorioallantoic membranes resulted in the formation of blood vessels in higher densities and with larger diameters, compared to other control conditions. Overall, the drug releasing system developed in this study will be broadly useful for regulating release rates of a wide array of protein drugs, and further enhance the quality of protein drug-based therapies.