Differential integrity of TALE nuclease genes following adenoviral and lentiviral vector gene transfer into human cells

The array of genome editing strategies based on targeted double-stranded DNA break formation have recently been enriched through the introduction of transcription activator-like type III effector (TALE) nucleases (TALENs). To advance the testing of TALE-based approaches, it will be crucial to deliver these custom-designed proteins not only into transformed cell types but also into more relevant, chromosomally stable, primary cells. Viral vectors are among the most effective gene transfer vehicles. Here, we investigated the capacity of human immunodeficiency virus type 1- and adenovirus-based vectors to package and deliver functional TALEN genes into various human cell types. To this end, we attempted to assemble particles of these two vector classes, each encoding a monomer of a TALEN pair targeted to a bipartite sequence within the AAVS1 ‘safe harbor’ locus. Vector DNA analyses revealed that adenoviral vectors transferred intact TALEN genes, whereas lentiviral vectors failed to do so, as shown by their heterogeneously sized proviruses in target cells. Importantly, adenoviral vector-mediated TALEN gene delivery resulted in site-specific double-stranded DNA break formation at the intended AAVS1 target site at similarly high levels in both transformed and non-transformed cells. In conclusion, we demonstrate that adenoviral, but not lentiviral, vectors constitute a valuable TALEN gene delivery platform.

Natural history of chronic HBV carriers in northern Italy: morbidity and mortality after 30 years

BACKGROUND & AIMS

Increased morbidity and mortality from liver disease have been reported in chronic hepatitis B surface antigen (HBsAg) carriers, but data on survival are equivocal. To assess the impact of hepatitis B virus (HBV) infection on survival and liver-related complications, we re-evaluated, after a mean follow-up of 30 years, a cohort of 296 blood donors excluded from donation 30 years ago when HBsAg screening became mandatory.

METHODS

Clinical and ultrasound examination and biochemical and virologic tests were performed. The cause of death was recorded and survival was compared with a control population of 157 HBV-negative blood donors selected at baseline.

RESULTS

Thirty-two (10.8%) cases and 14 controls (8.9%) ( P = 0.625) had died; 3 of 32 (9.3%) and 1 of 14 (7.1%) deaths were liver-related. Hepatocellular carcinoma (HCC) caused death in 2 of 296 and 1 of 157 subjects (0.6% in each group). Alcohol-induced cirrhosis occured in the remaining subject. By Cox regression analysis, survival was independently predicted by older age, abnormal gamma-glutamyl transpeptidase (GGT) levels, and presence of medical comorbidities at baseline. Unequivocal liver disease was found in 4 carriers only. No disease decompensation occurred during follow-up. Fifty-nine (32.2%) carriers cleared HBsAg (yearly incidence, 1.0%). Full-length serum HBV DNA was present in 32.2% of persistently HBsAg-positive individuals (average titer always <10 5 copies/mL).

CONCLUSIONS

Over a 30-year period, chronic HBV carrier blood donors from Northern Italy did not develop clinically significant liver disease, hepatocellular cancer, or other liver-related morbidity or mortality at a higher rate than uninfected controls. The presence of medical comorbidities, older age at diagnosis, and abnormal GGT levels were independent predictors of death among chronic HBV carriers.

Surgery of residual disease following molecular-targeted therapy with imatinib mesylate in advanced/metastatic GIST

OBJECTIVE

To explore the role of surgery of residual disease following a period of therapy with imatinib mesylate in advanced gastrointestinal stromal tumors (GIST).

METHODS

From January 2001 to June 2005, 159 patients with advanced/metastatic GIST were treated with imatinib mesylate at a single institution. As of June 2002, 38 patients were selected for surgery following a variable period of imatinib therapy. Twenty-seven patients were operated on while they were in response, 8 in progression, 3 for localized disease. Clinical, pathologic, and molecular features were assessed and are reported.

RESULTS

Postsurgery PFS was 96% at 12 months and 69% at 24 months for responding patients, while it was nil at 12 months for progressing ones. Disease-specific survival at 12 months was 100% for responding patients and 60% for progressing ones. In responding cases, secondary progression was mainly related to postsurgical imatinib discontinuation, irrespective of pathologic or molecular variables. In progressing patients, secondary resistance was mainly related to acquired mutations.

CONCLUSION

In advanced GIST patients who are responding to imatinib mesylate, the role of surgery is not formally demonstrated at the moment, but this option may well be considered investigational, or suitable for an individualized decision-making in the lack of evidence. In our series, patients progressing on imatinib mesylate did not seem to have any major benefit from surgery, although their number is low.

High-definition mapping of retroviral integration sites identifies active regulatory elements in human multipotent hematopoietic progenitors

Integration of retroviral vectors in the human genome follows nonrandom patterns that favor insertional deregulation of gene expression and increase the risk of their use in clinical gene therapy. The molecular basis of retroviral target site selection is still poorly understood. We used deep sequencing technology to build genomewide, high-definition maps of > 60 000 integration sites of Moloney murine leukemia virus (MLV)- and HIV-based retroviral vectors in the genome of human CD34(+) multipotent hematopoietic progenitor cells (HPCs) and used gene expression profiling, chromatin immunoprecipitation, and bioinformatics to associate integration to genetic and epigenetic features of the HPC genome. Clusters of recurrent MLV integrations identify regulatory elements (alternative promoters, enhancers, evolutionarily conserved noncoding regions) within or around protein-coding genes and microRNAs with crucial functions in HPC growth and differentiation, bearing epigenetic marks of active or poised transcription (H3K4me1, H3K4me2, H3K4me3, H3K9Ac, Pol II) and specialized chromatin configurations (H2A.Z). Overall, we mapped 3500 high-frequency integration clusters, which represent a new resource for the identification of transcriptionally active regulatory elements. High-definition MLV integration maps provide a rational basis for predicting genotoxic risks in gene therapy and a new tool for genomewide identification of promoters and regulatory elements controlling hematopoietic stem and progenitor cell functions.

Molecular and Biochemical Analyses of Platelet-Derived Growth Factor Receptor (PDGFR) B, PDGFRA, and KIT Receptors in Chordomas

PURPOSE

We have previously shown the presence of an activated platelet-derived growth factor (PDGF) receptor (PDGFR) B and its ligand PDGFB in a limited number of patients with clinical and radiological responses to imatinib mesylate treatment. This article describes the results of comprehensive molecular/biochemical analyses of the three receptors targeted by the drug (PDGFRB, PDGFRA, and KIT) in a series of 31 chordoma patients.

EXPERIMENTAL DESIGN

The presence and activation status of PDGFRB, PDGFRA, and KIT receptors were investigated by means of immunoprecipitation and Western blot analyses complemented by immunohistochemistry, their expression level was analyzed by means of real-time PCR, and the occurrence of activating point mutations was investigated by means of cDNA sequencing. The PDGFB, PDGFA, and stem cell factor cognate ligands were investigated by reverse transcription-PCR, and gene status was assessed by fluorescence in situ hybridization.

RESULTS

The results show that PDGFRB was highly expressed and phosphorylated, whereas PDGFRA and KIT were less expressed but phosphorylated and thus activated. These findings, together with the absence of gain-of-function mutations and the presence of the cognate ligands, strongly support the hypothesis that the activation mechanism is the autocrine/paracrine loop. No role seems to be played by gene amplification.

CONCLUSIONS

In the light of our findings, the clinical benefit observed in chordoma patients treated with imatinib seems to be attributable to the switching off of all three receptors.

Functional analyses and molecular modeling of two c-Kit mutations responsible for imatinib secondary resistance in GIST patients

Imatinib-acquired resistance related to the presence of secondary point mutations has become a frequent event in gastrointestinal stromal tumors. Here, transient transfection experiments with plasmids carrying two different KIT-acquired point mutations were performed along with immunoprecipitation of total protein extracts, derived from imatinib-treated and untreated cells. The molecular mechanics/Poisson Boltzmann surface area computational techniques were applied to study the interactions of the wild-type and mutated receptors with imatinib at the molecular level. Biochemical analyses showed KIT phosphorylation in cells transfected with vectors carrying the specific mutant genes. Imatinib treatment demonstrated that T670I was insensitive to the drug at all the applied concentrations, whereas V654A was inhibited by 6 microM of imatinib. The modeling of the mutated receptors revealed that both substitutions affect imatinib-binding site, but to a different extent: T670I substantially modifies the binding pocket, whereas V654A induces only relatively confined structural changes. We demonstrated that T670I and V654A cause indeed imatinib-acquired resistance and that the former is more resistant to imatinib than the latter. The application of molecular simulations allowed us to quantify the interactions between the mutated receptors and imatinib, and to propose a molecular rationale for this type of drug resistance.

Soluble TRAIL Armed Human MSC As Gene Therapy For Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is still one of the most aggressive adult cancers with an unacceptable prognosis. For this reason novel therapies accounting for PDAC peculiarities, such as the relevant stromal reaction, are urgently needed. Here adipose mesenchymal stromal/stem cells (AD-MSC) have been armed to constantly release a soluble trimeric and multimeric variant of the known anti-cancer TNF-related apoptosis-inducing ligand (sTRAIL). This cancer gene therapy strategy was in vitro challenged demonstrating that sTRAIL was thermally stable and able to induce apoptosis in the PDAC lines BxPC-3, MIA PaCa-2 and against primary PDAC cells. sTRAIL released by AD-MSC relocated into the tumor stroma was able to significantly counteract tumor growth in vivo with a significant reduction in tumor size, in cytokeratin-7+ cells and by an anti-angiogenic effect. In parallel, histology on PDAC specimens form patients (n = 19) was performed to investigate the levels of TRAIL DR4, DR5 and OPG receptors generating promising insights on the possible clinical translation of our approach. These results indicate that adipose MSC can very efficiently vehicle a novel TRAIL variant opening unexplored opportunities for PDAC treatment.

PDGFRα, PDGFRβ and KIT expression/activation in conventional chondrosarcoma

Chondrosarcomas represent 20% of all primary bone sarcomas, and many studies have attempted to unravel molecular targets for future development of new therapies. The aim of this study was to investigate the expression/activation of PDGFRalpha, PDGFRbeta and KIT receptor tyrosine kinases (RTKs) as potential therapeutic targets in conventional central primary chondrosarcomas (CCS). The expression of PDGFRalpha, PDGFRbeta and KIT RTKs was detected in 16 CCSs using immunohistochemistry (IHC), and their level of expression and activation status were analysed by immunoprecipitation and western blot experiments. PDGFRalpha, PDGFRbeta and KIT cDNAs were screened to verify the presence of activating mutations and the presence of the cognate ligands was analysed by means of RT-PCR. RTK gene amplification was further studied by means of fluorescence in situ hybridization (FISH) analysis. The immunophenotyping and biochemical analyses showed that the CCSs co-expressed PDGFRalpha and PDGFRbeta, with the latter showing definitively greater protein expression and phosphorylation levels. PDGFRbeta was expressed but not activated in control healthy joint cartilage, in line with no PDGFB detection. Conversely, the KIT gene product did not seem to play a relevant role. These findings, in the absence of activating mutations or an abnormal genomic profile and the presence of PDGFA and PDGFB expression, are consistent with an autocrine/paracrine loop activation of the corresponding receptors. The CCS gene profile described here offers a rationale for the use of RTK inhibitors alone or in combination with chemotherapy, and supports further investigation of RTKs and their downstream signals.

CRISPR/Cas9-Mediated In Situ Correction of LAMB3 Gene in Keratinocytes Derived from a Junctional Epidermolysis Bullosa Patient

Deficiency of basement membrane heterotrimeric laminin 332 component, coded by LAMA3, LAMB3, and LAMC2 genes, causes junctional epidermolysis bullosa (JEB), a severe skin adhesion defect. Herein, we report the first application of CRISPR/Cas9-mediated homology direct repair (HDR) to in situ restore LAMB3 expression in JEB keratinocytes in vitro and in immunodeficient mice transplanted with genetically corrected skin equivalents. We packaged an adenovector carrying Cas9/guide RNA (gRNA) tailored to the intron 2 of LAMB3 gene and an integration defective lentiviral vector bearing a promoterless quasi-complete LAMB3 cDNA downstream a splice acceptor site and flanked by homology arms. Upon genuine HDR, we exploited the in vitro adhesion advantage of laminin 332 production to positively select LAMB3-expressing keratinocytes. HDR and restored laminin 332 expression were evaluated at single-cell level. Notably, monoallelic-targeted integration of LAMB3 cDNA was sufficient to in vitro recapitulate the adhesive property, the colony formation typical of normal keratinocytes, as well as their cell growth. Grafting of genetically corrected skin equivalents onto immunodeficient mice showed a completely restored dermal-epidermal junction. This study provides evidence for efficient CRISPR/Cas9-mediated in situ restoration of LAMB3 expression, paving the way for ex vivo clinical application of this strategy to laminin 332 deficiency.

MSC-Delivered Soluble TRAIL and Paclitaxel as Novel Combinatory Treatment for Pancreatic Adenocarcinoma

Pancreatic cancer is the fourth leading cause of cancer death in western countries with more than 100,000 new cases per year in Europe and a mortality rate higher than 90%. In this scenario, advanced therapies based on gene therapies are emerging, thanks to a better understanding of tumour architecture and cancer cell alterations. We have demonstrated the efficacy of an innovative approach for pancreatic cancer based on mesenchymal stromal cells (MSC) genetically engineered to produce TNF-related Apoptosis Inducing Ligand (TRAIL). Here we investigated the combination of this MSC-based approach with the administration of a paclitaxel (PTX)-based chemotherapy to improve the potential of the treatment, also accounting for a possible resistance onset.

Methods: Starting from the BXPC3 cell line, we generated and profiled a TRAIL-resistant model of pancreatic cancer, testing the impact of the combined treatment in vitro with specific cytotoxicity and metabolic assays. We then challenged the rationale in a subcutaneous mouse model of pancreatic cancer, assessing its effect on tumour size accounting stromal and parenchymal organization.

Results: PTX was able to restore pancreatic cancer sensitivity to MSC-delivered TRAIL by reverting its pro-survival gene expression profile. The two compounds cooperate both in vitro and in vivo and the combined treatment resulted in an improved cytotoxicity on tumour cells.

Conclusion: In summary, this study uncovers the potential of a combinatory approach between MSC-delivered TRAIL and PTX, supporting the combination of cell-based products and conventional chemotherapeutics as a tool to improve the efficacy of the treatments, also addressing possible mechanisms of resistance.

Analysis of potential receptor tyrosine kinase targets in intimal and mural sarcomas

Primary sarcomas of the great vessels are very rare neoplasms and only a few cases have been reported. They are divided into the two broad categories of intimal or luminal and mural sarcomas. We analysed eight advanced high-grade sarcomas originating from major vessels (seven intimal and one mural sarcoma) by means of immunohistochemistry and FISH analysis for PDGFRA, PDGFRB, EGFR and KIT receptor tyrosine kinases (RTKs), together with immunoprecipitation/western blotting, sequencing of the corresponding genes, and the search for cognate ligands. The intimal sarcomas showed a wide spectrum of morphologies and immunophenotypes, whereas the mural sarcoma had common leiomyosarcomatous features. Regardless of their category, all of the cases had a PDGFRA-deregulated cytogenetic profile mainly consisting of an amplification cluster; five were also polysomic for PDGFRB, whereas three showed disomy. Six cases had a deregulated EGFR gene, and c-Kit gene status was similar to that of PDGFRA. In one case, biochemical analysis revealed the presence of activated and highly expressed PDGFRA, PDGFRB and EGFR, whereas KIT was expressed at reference level. Sequencing of the corresponding genes revealed no activating mutations in any of the analysed receptors. The cognate ligands were detected in all cases. In predictive terms, the evidence of gene amplification/high polysomy of several RTKs, together with PDGFRA, PDGFRB and EGFR expression and phosphorylation, suggests that these tumours may be sensitive to RTK-inhibiting treatments.

Methicillin-resistant Staphylococcus aureus eradication in cystic fibrosis patients: A randomized multicenter study

BACKGROUND

Few studies, based on a limited number of patients using non-uniform therapeutic protocols, have analyzed Methicillin-resistant Staphylococcus aureus (MRSA) eradication.

METHODS

In a randomized multicenter trial conducted on patients with new-onset MRSA infection we evaluated the efficacy of an early eradication treatment (arm A) compared with an observational group (B). Arm A received oral rifampicin and trimethoprim/sulfamethoxazole (21 days). Patients' microbiological status, FEV1, BMI, pulmonary exacerbations and use of antibiotics were assessed.

RESULTS

Sixty-one patients were randomized. Twenty-nine (47.5%) patients were assigned to active arm A and 32 (52.5%) patients to observational arm B. Twenty-nine (47.5%) patients, 10 patients in arm A and 19 in arm B, dropped out of the study. At 6 months MRSA was eradicated in 12 (63.2%) out of 19 patients in arm A while spontaneous clearance was observed in 5 (38.5%) out of 13 patients in arm B. A per-protocol analysis showed a 24.7% difference in the proportion of MRSA clearance between the two groups (z = 1.37, P(Z>z) = 0.08). Twenty-seven patients, 15 (78.9%) out of 19 in arm A and 12 (92.3%) out of 13 in arm B, were able to perform spirometry. The mean (±SD) FEV1 change from baseline was 7.13% (±14.92) in arm A and -1.16% (±5.25) in arm B (p = 0.08). In the same period the BMI change (mean ±SD) from baseline was 0.54 (±1.33) kg/m2 in arm A and -0.38 (±1.56) kg/m2 in arm B (p = 0.08). At 6 months no statistically significant differences regarding the number of pulmonary exacerbations, days spent in hospital and use of antibiotics were observed between the two arms.

CONCLUSIONS

Although the statistical power of the study is limited, we found a 24.7% higher clearance of MRSA in the active arm than in the observational arm at 6 months. Patients in the active arm A also had favorable FEV1 and BMI tendencies.

Mediterranean Diet in Developmental Age: A Narrative Review of Current Evidences and Research Gaps

Numerous studies in recent decades have shown that Mediterranean diet (MD) can reduce the risk of developing obesity in pediatric patients. The current narrative review summarizes recent evidence regarding the impact of MD across the different stages of child development, starting from fetal development, analyzing breastfeeding and weaning, through childhood up to adolescence, highlighting the gaps in knowledge for each age group. A literature search covering evidence published between 1 January 2000 and 1 March 2022 and concerning children only was conducted using multiple keywords and standardized terminology in PubMed database. A lack of scientific evidence about MD adherence concerns the age group undergoing weaning, thus between 6 months and one year of life. In the other age groups, adherence to MD and its beneficial effects in terms of obesity prevention has been extensively investigated, however, there are still few studies that correlate this dietary style with the incidence of non-communicable diseases. Furthermore, research on multi-intervention strategy should be implemented, especially regarding the role of education of children and families in taking up this healthy dietary style.

Infectious Risks Related to Umbilical Venous Catheter Dwell Time and Its Replacement in Newborns: A Narrative Review of Current Evidence

The use of umbilical venous catheters (UVCs) has become the standard of care in the neonatal intensive care unit (NICU) to administer fluids, medications and parenteral nutrition. However, it is well known that UVCs can lead to some serious complications, both mechanical and infective, including CLABSI (Central Line-Associated Bloodstream Infections). Most authors recommend removing UVC within a maximum of 14 days from its placement. However, the last Infusion Therapy Standards of Practice (INS) guidelines recommends limiting the UVC dwell time to 7 to 10 days, to reduce risks of infectious and thrombotic complications. These guidelines also suggest as an infection prevention strategy to remove UVC after 4 days, followed by the insertion of a PICC if a central line is still needed. Nevertheless, the maximum UVC dwell time to reduce the risk of CLABSI is still controversial, as well as the time of its replacement with a PICC. In this study we reviewed a total of 177 articles, found by using the PubMed database with the following search strings: "UVC AND neonates", "(neonate* OR newborn*) AND (UVC OR central catheter*) AND (infection*)". We also analyze the INS guidelines to provide the reader an updated overview on this topic. The purpose of this review is to give updated information on CVCs infectious risks by examining the literature in this field. These data could help clinicians in deciding the best time to remove or to replace the UVC with a PICC, to reduce CLABSIs risk. Despite the lack of strong evidence, the risk of CLABSI seems to be minimized when UVC is removed/replaced within 7 days from insertion and this indication is emerging from more recent and larger studies.

Transmission of Group B Streptococcus in late-onset neonatal disease: a narrative review of current evidence

Group B streptococcus (GBS) late-onset disease (LOD, occurring from 7 through 89 days of life) is an important cause of sepsis and meningitis in infants. The pathogenesis and modes of transmission of LOD to neonates are yet to be elucidated. Established risk factors for the incidence of LOD include maternal GBS colonisation, young maternal age, preterm birth, HIV exposure and African ethnicity. The mucosal colonisation by GBS may be acquired perinatally or in the postpartum period from maternal or other sources. Growing evidence has demonstrated the predominant role of maternal sources in the transmission of LOD. Intrapartum antibiotic prophylaxis (IAP) to prevent early-onset disease reduces neonatal GBS colonisation during delivery; however, a significant proportion of IAP-exposed neonates born to GBS-carrier mothers acquire the pathogen at mucosal sites in the first weeks of life. GBS-infected breast milk, with or without presence of mastitis, is considered a potential vehicle for transmitting GBS. Furthermore, horizontal transmission is possible from nosocomial and other community sources. Although unfrequently reported, nosocomial transmission of GBS in the neonatal intensive care unit is probably less rare than is usually believed. GBS disease can sometime recur and is usually caused by the same GBS serotype that caused the primary infection. This review aims to discuss the dynamics of transmission of GBS in the neonatal LOD.

Lumbar Puncture and Meningitis in Infants with Proven Early- or Late-Onset Sepsis: An Italian Prospective Multicenter Observational Study

Background: To evaluate the rates of lumbar puncture (LP) in infants with culture-proven sepsis. Study design: We prospectively enrolled 400 infants with early- or late-onset sepsis due to Group B streptococcus (GBS) or Eschericha coli, diagnosed within 90 days of life. Rates of LP and potential variables associated with LP performance were evaluated. Moreover, cerebrospinal fluid (CSF) characteristics and results of the molecular analysis were investigated. Results: LP was performed in 228/400 (57.0%) infants; 123/228 LPs (53.9%) were performed after antibiotic initiation, hampering the ability to identify the pathogen in the CSF culture. However, polymerase chain reaction increased the probability of positive results of CSF analysis compared to microbiological culture (28/79, 35.4% vs. 14/79, 17.7%, p = 0.001). Severe clinical presentation and GBS infection were associated with higher LP rates. The rate of meningitis was 28.5% (65/228). Conclusions: Rates of LP are low in culture-proven neonatal sepsis and antibiotics are frequently given before LP is carried out. Thus meningitis may be underestimated, and the chances of giving an effective therapy to the newborn are reduced. LP should be performed before the start of antibiotics when there is a clinical suspicion of infection.

Should we give antibiotics to neonates with mild non-progressive symptoms? A comparison of serial clinical observation and the neonatal sepsis risk calculator

OBJECTIVE

To compare two strategies [the neonatal sepsis risk calculator (NSC) and the updated serial clinical observation approach (SCO)] for the management of asymptomatic neonates at risk of early-onset sepsis (EOS) and neonates with mild non-progressive symptoms in the first hours of life.

METHODS

This was a single-center, retrospective cohort study conducted over 15 months (01/01/2019-31/03/2020). All live births at ≥34 weeks of gestation were included. Infants were managed using SCO and decisions were compared with those retrospectively projected by the NSC. The proportion of infants recommended for antibiotics or laboratory testing was compared in both strategies. McNemar's non-parametric test was used to assess significant differences in matched proportions.

RESULTS

Among the 3,445 neonates (late-preterm, n = 178; full-term, n = 3,267) 262 (7.6%) presented with symptoms of suspected EOS. There were no cases of culture-proven EOS. Only 1.9% of the neonates were treated with antibiotics (median antibiotic treatment, 2 days) and 4.0% were evaluated. According to NSC, antibiotics would have been administered in 5.4% of infants (absolute difference between SCO and NSC, 3.51%; 95% CI, 3.14-3.71%; p <0.0001) and 5.6% of infants would have undergone "rule out sepsis" (absolute difference between SCO and NSC, 1.63%, 95% CI 1.10-2.05; p <0.0001).

CONCLUSION

SCO minimizes laboratory testing and unnecessary antibiotics in infants at risk of EOS or with mild non-progressive symptoms, without the risk of a worse neonatal outcome. The NSC recommends almost three times more antibiotics than the SCO without improving neonatal outcomes.

Timing of Symptoms of Early-Onset Sepsis after Intrapartum Antibiotic Prophylaxis: Can It Inform the Neonatal Management?

The effectiveness of "inadequate" intrapartum antibiotic prophylaxis (IAP administered < 4 h prior to delivery) in preventing early-onset sepsis (EOS) is debated. Italian prospective surveillance cohort data (2003-2022) were used to study the type and duration of IAP according to the timing of symptoms onset of group B streptococcus (GBS) and E. coli culture-confirmed EOS cases. IAP was defined "active" when the pathogen yielded in cultures was susceptible. We identified 263 EOS cases (GBS = 191; E. coli = 72). Among GBS EOS, 25% had received IAP (always active when beta-lactams were administered). Most IAP-exposed neonates with GBS were symptomatic at birth (67%) or remained asymptomatic (25%), regardless of IAP duration. Among E. coli EOS, 60% were IAP-exposed. However, IAP was active in only 8% of cases, and these newborns remained asymptomatic or presented with symptoms prior to 6 h of life. In contrast, most newborns exposed to an "inactive" IAP (52%) developed symptoms from 1 to >48 h of life. The key element to define IAP "adequate" seems the pathogen's antimicrobial susceptibility rather than its duration. Newborns exposed to an active antimicrobial (as frequently occurs with GBS infections), who remain asymptomatic in the first 6 h of life, are likely uninfected. Because E. coli isolates are often unsusceptible to beta-lactam antibiotics, IAP-exposed neonates frequently develop symptoms of EOS after birth, up to 48 h of life and beyond.

Escherichia coli Is Overtaking Group B Streptococcus in Early-Onset Neonatal Sepsis

The widespread use of intrapartum antibiotic prophylaxis (IAP) to prevent group B streptococcus (GBS) early-onset sepsis (EOS) is changing the epidemiology of EOS. Italian prospective area-based surveillance data (from 1 January 2016 to 31 December 2020) were used, from which we identified 64 cases of culture-proven EOS (E. coli, n = 39; GBS, n = 25) among 159,898 live births (annual incidence rates of 0.24 and 0.16 per 1000, respectively). Approximately 10% of E. coli isolates were resistant to both gentamicin and ampicillin. Five neonates died; among them, four were born very pre-term (E. coli, n = 3; GBS, n = 1) and one was born full-term (E. coli, n = 1). After adjustment for gestational age, IAP-exposed neonates had ≥95% lower risk of death, as compared to IAP-unexposed neonates, both in the whole cohort (OR 0.04, 95% CI 0.00-0.70; p = 0.03) and in the E. coli EOS cohort (OR 0.05, 95% CI 0.00-0.88; p = 0.04). In multi-variable logistic regression analysis, IAP was inversely associated with severe disease (OR = 0.12, 95% CI 0.02-0.76; p = 0.03). E. coli is now the leading pathogen in neonatal EOS, and its incidence is close to that of GBS in full-term neonates. IAP reduces the risk of severe disease and death. Importantly, approximately 10% of E. coli isolates causing EOS were found to be resistant to typical first-line antibiotics.

Enteral and Parenteral Treatment with Caffeine for Preterm Infants in the Delivery Room: A Randomised Trial

BACKGROUND

Early treatment with caffeine in the delivery room (DR) has been proposed to decrease the need for mechanical ventilation (MV) by limiting episodes of apnoea and improving respiratory mechanics in preterm infants. Our aim was to verify the hypothesis that intravenous or enteral administration of caffeine can be performed in the preterm infant in the DR.

METHODS

Infants with 25±0-29±6 weeks of gestational age were enrolled and randomised to receive 20 mg/kg of caffeine citrate intravenously, via the umbilical vein, or enterally, through an orogastric tube, within 10 min of birth. Caffeine blood level was measured at 60 ± 15 min after administration and 60 ± 15 min before the next dose (5 mg/kg). The primary endpoint was evaluation of the success rate of intravenous and enteral administration of caffeine in the DR.

RESULTS

Nineteen patients were treated with intravenous caffeine and 19 with enteral caffeine. In all patients the procedure was successfully performed. Peak blood level of caffeine 60 ± 15 min after administration in the DR was found to be below the therapeutic range (5 µg/mL) in 25 % of samples and above the therapeutic range in 3%. Blood level of caffeine 60 ± 15 min before administration of the second dose was found to be below the therapeutic range in 18% of samples.

CONCLUSIONS

Intravenous and enteral administration of caffeine can be performed in the DR without interfering with infants' postnatal assistance. Some patients did not reach the therapeutic range, raising the question of which dose is the most effective to prevent MV.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT04044976; EudraCT number 2018-003626-91.

Transcriptionally regulated and nontoxic delivery of the hyperactive Sleeping Beauty Transposase

The Sleeping Beauty (SB) transposase and, in particular, its hyperactive variant SB100X raises increasing interest for gene therapy application, including genome modification and, more recently, induced pluripotent stem cells (iPS) reprogramming. The documented cytotoxicity of the transposase, when constitutively expressed by an integrating retroviral vector (iRV), has been circumvented by the transient delivery of SB100X using retroviral mRNA transfer. In this study, we developed an alternative, safe, and efficient transposase delivery system based on a tetracycline-ON regulated expression cassette and the rtTA2(S)-M2 transactivator gene transiently delivered by integration-defective lentiviral vectors (IDLVs). Compared with iRV-mediated delivery, expression of tetracycline-induced SB100X delivered by an IDLV results in more efficient integration of a GFP transposon and reduced toxicity. Tightly regulated expression and reactivation of the transposase was achieved in HeLa cells as wells as in human primary keratinocytes. Based on these properties, the regulated transposase-IDLV vectors may represent a valuable tool for genetic engineering and therapeutic gene transfer.

Neurodevelopmental Outcome after Culture-Proven or So-Called Culture-Negative Sepsis in Preterm Infants

(1) Background: Prematurity is a serious condition associated with long-term neurological disability. This study aimed to compare the neurodevelopmental outcomes of preterm neonates with or without sepsis. (2) Methods: This single-center retrospective case-control study included infants with birth weight < 1500 g and/or gestational age ≤ 30 weeks. Short-term outcomes, brain MRI findings, and severe functional disability (SFD) at age 24 months were compared between infants with culture-proven or culture-negative sepsis or without sepsis. A chi-squared test or Mann-Whitney U test was used to compare the clinical and instrumental characteristics and the outcomes between cases and controls. (3) Results: Infants with sepsis (all sepsis n = 76; of which culture-proven n = 33 and culture-negative n = 43) were matched with infants without sepsis (n = 76). Compared with infants without sepsis, both all sepsis and culture-proven sepsis were associated with SFD. In multivariate logistic regression analysis, SFD was associated with intraventricular hemorrhage (OR 4.7, CI 1.7-13.1, p = 0.002) and all sepsis (OR 3.68, CI 1.2-11.2, p = 0.021). (4) Conclusions: All sepsis and culture-proven sepsis were associated with SFD. Compared with infants without sepsis, culture-negative sepsis was not associated with an increased risk of SFD. Given the association between poor outcomes and culture-proven sepsis, its prevention in the neonatal intensive care unit is a priority.