Near-Infrared Spectroscopy and Continuous Glucose Monitoring During Therapeutic Hypothermia.

The relation between glucose homeostasis and cerebral blood flow (CBF) and their correlation to outcome in neonatal hypoxic-ischemic encephalopathy are unclear. In this short communication, we tried to determine whether changes in regional oxygen saturation (rSO2), as measured by near-infrared spectroscopy (NIRS), in asphyxiated neonates during therapeutic hypothermia correlate with the glycemic profile and whether NIRS and continuous glucose monitoring are useful in identifying cooled asphyxiated neonates at high risk of brain injury. Although there was no correlation between blood glucose and CBF in this small cohort of asphyxiated neonates (13 neonates admitted to the IRCCS Giannina Gaslini NICU in Genoa between March and September 2021), after 24 h of life, increased rSO2 and glucose variability with a tendency toward hyperglycemia distinguished neonates who subsequently acquired brain injury from those who did not. As a result of this, it may be possible to monitor cerebral perfusion and metabolic changes as soon as possible after delivery in order to prevent poorer outcomes.

Case Report: Susceptibility to viral infections and secondary hemophagocytic lymphohistiocytosis responsive to intravenous immunoglobulin as primary manifestations of adenosine deaminase 2 deficiency.

Deficiency of adenosine deaminase 2 (DADA2) is an autosomal recessive disease associated with a highly variable clinical presentation, including systemic vasculitis, immunodeficiency, and cytopenia. We report a case of a 16-year-old girl affected by recurrent viral infections [including cytomegalovirus (CMV)-related hepatitis and measles vaccine virus-associated manifestations] and persistent inflammation, which occurred after Parvovirus infection and complicated by secondary hemophagocytic lymphohistiocytosis (HLH). HLH's first episode presented at 6 years of age and was preceded by persistent fever and arthralgia with evidence of Parvovirus B19 infection. The episode responded to intravenous steroids but relapsed during steroids tapering. High-dose intravenous immunoglobulin (IVIG) helped manage her clinical symptoms and systemic inflammation. The frequency of IVIG administration and the dosage were progressively reduced. At the age of 9, she experienced varicella zoster virus (VZV) reactivation followed by the recurrence of the inflammatory phenotype complicated by HLH with neurological involvement. Again, high-dose steroids and monthly IVIG resulted in a quick response. Targeted next-generation sequencing (NGS) for autoinflammatory diseases and immunodeficiencies revealed the homozygous Leu183Pro ADA2 mutation, which was confirmed by Sanger analysis. ADA2 enzymatic test showed a complete loss of ADA2 activity. For about 3 years, IVIG alone was completely effective in preventing flares of inflammation and neurological manifestations. Anti-TNF treatment was started at the age of 13 for the appearance of recurrent genital ulcers, with a complete response. This case further expands the clinical spectrum of DADA2 and emphasizes the importance of extensive genetic testing in clinical phenotypes characterized by persistent unspecific inflammatory syndromes. The use of high doses of IVIG might represent a possible effective immune modulator, especially in combination with anti-TNF treatment.

Monitoring cell endocytosis of liposomes by real-time electrical impedance spectroscopy.

Evaluation and understanding the effect of drug delivery in in vitro systems is fundamental in drug discovery. We present an assay based on real-time electrical impedance spectroscopy (EIS) measurements that can be used to follow the internalisation and cytotoxic effect of a matrix metalloproteinase (MMP)-sensitive liposome formulation loaded with oxaliplatin (OxPt) on colorectal cancer cells. The EIS response identified two different cellular processes: (i) a negative peak in the cell index (CI) within the first 5 h, due to onset of liposome endocytosis, followed by (ii) a subsequent CI increase, due to the reattachment of cells until the onset of cytotoxicity with a decrease in CI. Free OxPt or OxPt-loaded Stealth liposomes did not show this two-stage EIS response; the latter can be due to the fact that Stealth cannot be cleaved by MMPs and thus is not taken up by the cells. Real-time bright-field imaging supported the EIS data, showing variations in cell adherence and cell morphology after exposure to the different liposome formulations. A drastic decrease in cell coverage as well as rounding up of cells during the first 5 h of exposure to OxPt-loaded (MMP)-sensitive liposome formulation is reflected by the first negative EIS response, which indicates the onset of liposome endocytosis. Graphical abstract.

Automated on-chip analysis of tuberculosis drug-resistance mutation with integrated DNA ligation and amplification.

Detection of a single base mutation in Mycobacterium tuberculosis DNA can provide fast and highly specific diagnosis of antibiotic-resistant tuberculosis. Mutation-specific ligation of padlock probes (PLPs) on the target followed by rolling circle amplification (RCA) is highly specific, but challenging to integrate in a simple microfluidic device due to the low temperature stability of the phi29 polymerase and the interference of phi29 with the PLP annealing and ligation. Here, we utilized the higher operation temperature and temperature stability of Equiphi29 polymerase to simplify the integration of the PLP ligation and RCA steps of an RCA assay in two different strategies performed at uniform temperature. In strategy I, PLP annealing took place off-chip and the PLP ligation and RCA were performed in one pot and the two reactions were clocked by a change of the temperature. For a total assay time of about 1.5 h, we obtained a limit of detection of 2 pM. In strategy II, the DNA ligation mixture and the RCA mixture were separated into two chambers on a microfluidic disc. After on-disc PLP annealing and ligation, the disc was spun to mix reagents and initiate RCA. For a total assay time of about 2 h, we obtained a limit of detection of 5 pM. Graphical abstract.

Optomagnetic Detection of Rolling Circle Amplification Products.

Rolling circle amplification (RCA) of a synthetic nucleic acid target is detected using magnetic nanoparticles (MNPs) combined with an optomagnetic (OM) readout. Two RCA assays are developed with on-chip detection of rolling circle products (RCPs) either at end-point where MNPs are mixed with the sample after completion of RCA or in real time where MNPs are mixed with the sample during RCA. The plastic chip acts as a cuvette, which is positioned in a setup integrated with temperature control and simultaneous detection of four parallel DNA hybridization reactions between functionalized MNPs and products of DNA amplification. The OM technique probes the small-angle rotation of MNPs bearing oligonucleotide probes complementary to the repeated nucleotide sequence of the RCPs. This rotation is restricted when MNPs bind to RCPs, which can be observed as a turn-off of the signal from MNPs that are free to rotate. The amount of MNPs bound to RCPs is found to increase in response to the amplification time as well as in response to the synthetic DNA target concentration (2-40 pM dynamic range). We report OM real-time results obtained with MNPs present during RCA and compare to relevant end-point OM results for RCPs generated for different RCA times. The real-time approach avoids opening of tubes post-RCA and thus reduces risk of lab contamination with amplification products without compromising the sensitivity and dynamic range of the assay.

Integration of microbead DNA handling with optomagnetic detection in rolling circle amplification assays.

Rolling circle amplification (RCA) is a linear isothermal amplification technique that is widely applied in biomolecular assays due to its high specificity. Handling of a target sample using magnetic microbeads (MMBs) in a multi-step assay is appealing as the MMBs enable separation and transportation using an external magnet. Detection of amplicons using optomagnetic measurements of the rotational diffusion properties of magnetic nanoparticles (MNPs) is also appealing as it can be performed on any transparent sample container. Two strategies are described for integration of MMB sample handling in an RCA assay with on-chip optomagnetic detection of the amplification products. The first strategy relies on selective and irreversible release of the amplicons from the MMBs so that the binding of functionalized MNPs to the amplicons can be detected optomagnetically. The second strategy relies on the incorporation of MNPs into RCA products during RCA, followed by their separation on MMBs and subsequent optomagnetic detection upon release from the RCA products. Using MMB handling of RCA steps, the limits of detection (LODs) for a synthetic DNA target representative of Victoria Influenza type B were found to be between 4 and 20 pM with total assay times between 2 and 2.5 h. Without magnetic microbead sample handling, the LOD was 200 fM. The findings provide deeper insight into the use of magnetic microbeads as solid substrates to handle a DNA target for integration of RCA as well as other DNA-based assays. Graphical Abstract Schematic illustration of magnetic microbeads transporting a DNA target through the steps in a rolling circle amplification assay. Optomagnetic measurements detect the binding of magnetic nanoparticles to amplicons released from microbeads (top) or the pH-induced release of magnetic nanoparticles trapped in amplicons (bottom).

Integration of rolling circle amplification and optomagnetic detection on a polymer chip.

Rolling circle amplification (RCA) combined with padlock probe recognition of a DNA target is attractive for on-chip nucleic acid testing due to its high specificity and isothermal reaction conditions. However, the integration of RCA on an automated chip platform is challenging due to the different reagents needed for the reaction steps and the temperature sensitivity of the phi29 polymerase. Here, we describe the integration of an RCA assay on a single-use polymer chip platform where magnetic microbeads are used as solid support to transport the DNA target between three connected reaction chambers for (i) padlock probe annealing and ligation, (ii) RCA, and (iii) optomagnetic detection of RCA products. The three chambers were loaded with reagents by sequential filling combined with passive microfluidic structures. After loading, the on-chip assay steps were automated. For an assay in which all steps but the padlock probe annealing on the target were performed on-chip, we found a limit of detection (LOD) for a synthetic influenza target of 2 pM after 45 min of RCA, which is comparable to the corresponding laboratory assay. The entire assay, including padlock probe annealing, could be performed on-chip with an LOD of 20 pM after 45 min of RCA. This LOD can likely be reduced by further optimizing the microbead mixing. The results present important steps towards the integration and automation of RCA and potentially also other complex multi-step assays on a single-use polymer chip for molecular analysis.

Ultrasensitive Real-Time Rolling Circle Amplification Detection Enhanced by Nicking-Induced Tandem-Acting Polymerases.

Padlock probe ligation-based rolling circle amplification (RCA) can distinguish single-nucleotide variants, which is promising for the detection of drug-resistance mutations in, e.g., Mycobacterium tuberculosis (Mtb). However, the clinical application of conventional linear RCA is restricted by its unsatisfactory picomolar-level limit of detection (LOD). Herein, we demonstrate the mechanism of a nicking-enhanced RCA (NickRCA) strategy that allows several polymerases to act simultaneously on the same looped template, generating single-stranded amplicon monomers. Limiting factors of NickRCA are investigated and controlled for higher amplification efficiency. Thereafter, we describe a NickRCA-based magnetic nanoparticle (MNP) dimer formation strategy combined with a real-time optomagnetic sensor monitoring MNP dimers. The proposed methodology is applied for the detection of a common Mtb rifampicin-resistance mutation, rpoB 531 (TCG/TTG). Without additional operation steps, an LOD of 15 fM target DNA is achieved with a total assay time of ca. 100 min. Moreover, the proposed biosensor holds the advantages of single-nucleotide mutation discrimination and the robustness to quantify targets in 10% serum samples. NickRCA produces short single-stranded monomers instead of the DNA coils produced in conventional RCA, which makes it more convenient for downstream operation, immobilization or detection, thus being applicable with different molecular tools and biosensors.

Successful ceftazidime-avibactam treatment of post-surgery Burkholderia multivorans genomovar II bacteremia and brain abscesses in a young lung transplanted woman with cystic fibrosis.

Burkholderia cepacia complex (Bcc) includes several phenotypically similar but genotypically distinct gram-negative bacteria (GNB) that can colonize the respiratory tract of Cystic Fibrosis (CF) patients. Pathogens are difficult to treat due to intrinsic resistance to multiple antibiotics and are associated to a more rapid decline in lung function and to increased mortality, particularly after lung transplantation. For all these reasons, chronic infection by Burkholderia (B) cenocepacia is presently considered a relative or absolute contraindication in almost all lung transplant centres. We report the case of a young adult CF patient chronically colonized by B multivorans genomovar II, with diabetes and end-stage renal disease treated with renal replacement therapy: a few months after lung transplantation, she developed post-surgery B multivorans bacteremia and multiple brain abscesses. This severe infection did not improve despite multiple standard antibiotic regimen. The introduction of ceftazidime-avibactam, a new ß-lactam/ ß-lactamase inhibitor combination resulted in clinical recovery and in radiological and biochemical improvement.

Determinants of breastfeeding discontinuation in an Italian cohort of mother-infant dyads in the first six months of life: a randomized controlled trial.

BACKGROUND: Among breastfeeding determinants, the marketing of breast milk substitutes might contribute to suboptimal breastfeeding rates. The aim of this study was to investigate the effect of receiving information on breast milk substitutes on breastfeeding rates. METHODS: We conducted a randomized, single-blind, controlled trial from 2012 to 2014 in a northern Italian maternity ward. We enrolled 802 Caucasian mothers who gave birth to healthy, full-term singletons with a birth weight > 2500 g and who were exclusively breastfeeding from delivery to discharge. Mothers who gave birth to infants with congenital diseases, chromosomal abnormalities, perinatal infections and/or cardio-respiratory instability and/or mothers being affected by endocrine and/or metabolic and/or gastrointestinal and/or renal diseases were excluded. Mothers were randomized to either receive (group A, n = 405) or not (group B, n = 397) written information on a breast milk substitute at discharge. Breastfeeding was promoted and supported in all mother-infant pairs equally. The mode of feeding for up to 6 months after delivery was determined by phone interview. To detect a 10% difference between groups in the discontinuation rate of exclusive breastfeeding at three months of age at 5% significance and 80% power, a total of 356 mother-infant pairs per group were needed. RESULTS: The exclusive breastfeeding prevalence was 91% and 92% at 7 days, 79% and 70% at 1 month, 75% and 66% at 2 months, 72% and 62% at 3 months, and 3% and 2% at 6 months in groups A and B, respectively. The relative risk (95% confidence interval) of exclusive breastfeeding (group A vs B) at 7 days and at 1, 2, 3 and 6 months was as follows: 0.99 (0.95-1.03), 1.12 (1.03-1.21), 1.13 (1.03-1.24), 1.15 (1.04-1.27), and 1.49 (0.62-3.61). Nutritional, lifestyle and lactational factors were the primary contributing determinants to early breastfeeding discontinuation. CONCLUSIONS: The present findings indicate that receiving written information on breast milk substitutes at hospital discharge, provided that breastfeeding support and education are offered, does not negatively affect breastfeeding rates. TRIAL REGISTRATION: NCT03208114. Registered 5 July 2017.

ADA2 deficiency (DADA2) as an unrecognised cause of early onset polyarteritis nodosa and stroke: a multicentre national study.

OBJECTIVES: To analyse the prevalence of CECR1 mutations in patients diagnosed with early onset livedo reticularis and/or haemorrhagic/ischaemic strokes in the context of inflammation or polyarteritis nodosa (PAN). Forty-eight patients from 43 families were included in the study. METHODS: Direct sequencing of CECR1 was performed by Sanger analysis. Adenosine deaminase 2 (ADA2) enzymatic activity was analysed in monocyte isolated from patients and healthy controls incubated with adenosine and with or without an ADA1 inhibitor. RESULTS: Biallelic homozygous or compound heterozygous CECR1 mutations were detected in 15/48 patients. A heterozygous disease-associated mutation (p.G47V) was observed in two affected brothers. The mean age of onset of the genetically positive patients was 24 months (6 months to 7 years). Ten patients displayed one or more cerebral strokes during their disease course. Low immunoglobulin levels were detected in six patients. Thalidomide and anti-TNF (tumour necrosis factor) blockers were the most effective drugs. Patients without CECR1 mutations had a later age at disease onset, a lower prevalence of neurological and skin manifestations; one of these patients displayed all the clinical features of adenosine deaminase 2deficiency (DADA2) and a defective enzymatic activity suggesting the presence of a missed mutation or a synthesis defect. CONCLUSIONS: DADA2 accounts for paediatric patients diagnosed with PAN-like disease and strokes and might explain an unrecognised condition in patients followed by adult rheumatologist. Timely diagnosis and treatment with anti-TNF agents are crucial for the prevention of severe complications of the disease. Functional assay to measure ADA2 activity should complement genetic testing in patients with non-confirming genotypes.

Intervention for promoting breast milk use in neonatal intensive care unit: a pilot study.

OBJECTIVE: The health benefits provided by breast milk are significant in preterm infants. Despite recommendations, rates of breastfeeding in preterm infants are lower than in term infants. The aim of this study was to evaluate the efficacy of a multidisciplinary intervention in promoting any breastfeeding in preterm infants at discharge. METHODS: A prospective non-randomized interventional cohort study was conducted. One hundred and twenty-two preterm infants constituted the historical group. A multidisciplinary intervention was performed including staff training and setting up and implementation of a written breastfeeding procedure. RESULTS: One hundred and ten preterm infants were enrolled in the intervention group. The percentage of infants fed human milk at discharge was 69 and 62 in the intervention group and in the historical group, respectively. The percentage change from any breastfeeding at full enteral feeding attainment to formula feeding at discharge was lower in the intervention group than in the historical group (-9 versus -23). Belonging to the intervention group and having at least one stress factor during pregnancy were independently associated with any breast milk feeding at discharge. CONCLUSIONS: The multidisciplinary intervention performed appears to be effective in promoting any breastfeeding in preterm infants at discharge.

Body composition changes in the first 6 months of life according to method of feeding.

BACKGROUND: Early feeding choices may affect long-term health outcomes. Therefore, understanding body composition changes in healthy breastfed infants has become an important research focus. OBJECTIVES: The aims of this review were to investigate the body composition changes that occur during weight loss in breastfed term newborns and to examine body composition differences between exclusively/predominantly breastfed and exclusively formula-fed infants in the first 6 months of life. METHODS: We performed a review of the existing literature using PubMed. We searched for studies published in English since January 1, 2000, that involved human infants ranging in age from birth to 6 months. We used the following MEDLINE Medical Subject Headings: ((breastfeeding) OR (infant formula)) AND ((body composition) OR (bioelectrical impedance) OR (absorptiometry, photon) OR (total body potassium) OR (isotope dilution) OR (air-displacement plethysmography)). Our search yielded 6 studies. RESULTS: Two studies reported that newborn weight loss was due to a reduction in the quantity of both fat mass and fat-free mass. Three out of 4 articles that evaluated body composition changes according to method of feeding reported no differences in body composition between exclusively/predominantly breastfed and exclusively formula-fed infants in the first 4.5 months of life. One study reported that exclusively breastfed infants at 3 months of age and exclusively breastfed boys at 6 months of age had higher fat mass contents compared to exclusively formula-fed infants. CONCLUSION: Because of the limited number of studies available, larger studies are needed to clarify the differences in body composition between exclusively/predominantly breastfed and exclusively formula-fed infants.

Nutrition and growth in infants born preterm from birth to adulthood.

Prevention of extra-uterine growth retardation is of extreme importance, as the achievement of adequate growth has been associated with a favorable neurodevelopmental outcome through childhood. In addition, as disturbances in growth that take place early in life may affect adult health, a full understanding of the growth trajectory of very-low-birth-weight infants is also advisable. This review will focus attention on the nutritional strategies proposed during hospital admission and after discharge in order to limit extra-uterine growth retardation in preterm infants. The dynamic changes that characterize growth of infants born preterm from birth up to adulthood will also be addressed.

The influence of a formula supplemented with dairy lipids and plant oils on the erythrocyte membrane omega-3 fatty acid profile in healthy full-term infants: a double-blind randomized controlled trial.

BACKGROUND: Human milk is the optimal nutrition for infants. When breastfeeding is not possible, supplementation of infant formula with long chain polyunsaturated fatty acids appears to promote neurodevelopmental outcome and visual function. Plant oils, that are the only source of fat in most of infant formulas, do not contain specific fatty acids that are present in human and cow milk and do not encounter milk fat triglyceride structure. Experimental data suggest that a mix of dairy lipids and plant oils can potentiate endogenous synthesis of n-3 long chain polyunsaturated fatty acids. This trial aims to determine the effect of an infant formula supplemented with a mixture of dairy lipids and plant oils on the erythrocyte membrane omega-3 fatty acid profile in full-term infants (primary outcome). Erythrocyte membrane long chain polyunsaturated fatty acids and fatty acids content, the plasma lipid profile and the insulin-growth factor 1 level, the gastrointestinal tolerance, the changes throughout the study in blood fatty acids content, in growth and body composition are evaluated as secondary outcomes. METHODS/DESIGN: In a double-blind controlled randomized trial, 75 healthy full-term infants are randomly allocated to receive for four months a formula supplemented with a mixture of dairy lipids and plant oils or a formula containing only plant oils or a formula containing plant oils supplemented with arachidonic acid and docosahexaenoic acid. Twenty-five breast-fed infants constitute the reference group. Erythrocyte membrane omega-3 fatty acid profile, long chain polyunsaturated fatty acids and the other fatty acids content, the plasma lipid profile and the insulin-growth factor 1 level are measured after four months of intervention. Gastrointestinal tolerance, the changes in blood fatty acids content, in growth and body composition, assessed by means of an air displacement plethysmography system, are also evaluated throughout the study. DISCUSSION: The achievement of an appropriate long chain polyunsaturated fatty acids status represents an important goal in neonatal nutrition. Gaining further insight in the effects of the supplementation of a formula with dairy lipids and plant oils in healthy full-term infants could help to produce a formula whose fat content, composition and structure is more similar to human milk. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT01611649.