Sequence-defined antibody-recruiting macromolecules.

Antibody-recruiting molecules represent a novel class of therapeutic agents that mediate the recruitment of endogenous antibodies to target cells, leading to their elimination by the immune system. Compared to single-ligand copies, macromolecular scaffolds presenting multiple copies of an antibody-binding ligand offer advantages in terms of increased complex avidity. In this study, we describe the synthesis of sequence-defined macromolecules designed for antibody recruitment, utilising dinitrophenol (DNP) as a model antibody-recruiting motif. The use of discrete macromolecules gives access to varying the spacing between DNP motifs while maintaining the same chain length. This characteristic enables the investigation of structure-dependent binding interactions with anti-DNP antibodies. Through solid-phase thiolactone chemistry, we synthesised a series of oligomers with precisely localised DNP motifs along the backbone and a terminal biotin motif for surface immobilisation. Utilising biolayer interferometry analysis, we observed that oligomers with adjacent DNP motifs exhibited enhanced avidity for anti-DNP antibodies. Molecular modelling provided insights into the structures and dynamics of the various macromolecules, shedding light on the accessibility of the ligands to the antibodies. Overall, our findings highlight that the use of sequence-defined macromolecules can contribute to our understanding of structure-activity relationships and provide insights for the design of novel antibody-recruiting therapeutic agents.

Molsidomine decreases hyperoxia-induced lung injury in neonatal rats.

BACKGROUND: The study's objective is to evaluate if Molsidomine (MOL), an anti-oxidant, anti-inflammatory, and anti-apoptotic drug, is effective in treating hyperoxic lung injury (HLI). METHODS: The study consisted of four groups of neonatal rats characterized as the Control, Control+MOL, HLI, HLI + MOL groups. Near the end of the study, the lung tissue of the rats were evaluated with respect to apoptosis, histopathological damage, anti-oxidant and oxidant capacity as well as degree of inflammation. RESULTS: Compared to the HLI group, malondialdehyde and total oxidant status levels in lung tissue were notably reduced in the HLI + MOL group. Furthermore, mean superoxide dismutase, glutathione peroxidase, and glutathione activities/levels in lung tissue were significantly higher in the HLI + MOL group as compared to the HLI group. Tumor necrosis factor-α and interleukin-1ß elevations associated with hyperoxia were significantly reduced following MOL treatment. Median histopathological damage and mean alveolar macrophage numbers were found to be higher in the HLI and HLI + MOL groups when compared to the Control and Control+MOL groups. Both values were increased in the HLI group when compared to the HLI + MOL group. CONCLUSIONS: Our research is the first to demonstrate that bronchopulmonary dysplasia may be prevented through the protective characteristics of MOL, an anti-inflammatory, anti-oxidant, and anti-apoptotic drug. IMPACT: Molsidomine prophylaxis significantly decreased the level of oxidative stress markers. Molsidomine administration restored the activities of antioxidant enzymes. Molsidomine prophylaxis significantly reduced the levels of inflammatory cytokines. Molsidomine may provide a new and promising therapy for BPD in the future. Molsidomine prophylaxis decreased lung damage and macrophage infiltration in the tissue.

Acute kidney injury and peritoneal dialysis in extremely low birth weight newborns.

BACKGROUND: In 12.5-56% of extremely low birth weight (ELBW) infants treated in newborn units, acute kidney injury (AKI) develops. Some of these infants may need renal replacement therapy for several reasons including hyperkalemia, hypovolemia and resistant acidosis. METHODS: All ELBW infants who were followed in our hospital between January 2015 and December 2017 and who lived longer than 48 hours were assessed. Patients were followed for AKI and peritoneal dialysis (PD). RESULTS: AKI developed in 25 of 201 ELBW infants. PD was administered to nine patients. PD was initiated at a median of 11 days (2-22 days) for all patients due to hyperkalemia which did not respond to medical treatment. Three of the nine infants who received PD died while dialysis was ongoing. The remaining six patients completed PD successfully. In these patients, the serum potassium value returned to normal in three days, and dialysis was continued for a median of 93 hours (40-172 hours). Dialysis leakage occurred in two patients, and hyperglycemia developed in two patients. On average, diuresis started at the 25th hour (8-40th hour). CONCLUSIONS: In the renal failure treatment of ELBW infants, PD is the only option which can be used for many units. It was found that in ELBW infants, who had wider peritoneal surface when compared to their body weight, biochemical values recovered rapidly with PD, and diuresis started a short while later in most patients.

Mortality related factors on hypoxic ischemic encephalopathic patients treated with therapeutic hypothermia: an 11-year single-center experience.

BACKGROUND: Hypoxic-ischemic encephalopathy (HIE) is a condition that may cause multiple organ dysfunction and has a high rate of mortality and morbidity. Therapeutic hypothermia is the only proven treatment that decreases the sequel and mortality rate of neonates that are born after 36 weeks of pregnancy and have moderate-severe HIE. METHODS: Our study was a single-center, retrospective study that includes newborns (gestational age ≥ 36 weeks) who underwent therapeutic hypothermia due to hypoxic-ischemic encephalopathy between 2010 and 2020. We evaluated 125 patients who were diagnosed with moderate to severe HIE and received therapeutic hypothermia. Demographic and clinical data were obtained from electronic medical records and patient files. The patients were separated into two groups as exitus group (n = 39) and discharged group (n = 86). We aimed to evaluate factors affecting mortality. RESULTS: We determined that the median resuscitation times were longer in the delivery room [retrospectively, 10th minutes (0-30) vs. 1 min (0-20), p < 0.05], the tenth min APGAR scores were lower [respectively, 4 (0-7) vs. 6 (3-10), p < 0.05], and the median pH value in the first blood gas taken was lower [respectively, 6.87 (6.4-7.14) vs. 6.90 (6.58-7.12), p < 0.05] in the exitus group. We also determined that multiple organ dysfunction is seen more often in the exitus group. DISCUSSION: This study demonstrated that the depth of acidosis in the blood gas, multiple organ dysfunction, and the existence of early-onset seizures are the signs of poor prognosis. Therefore, physicians need to be aware of such prognostic factors to follow these patients more closely in terms of possible complications and to inform their parents.

Intravenous Immunoglobulin Use in Hemolytic Disease Due to ABO Incompatibility to Prevent Exchange Transfusion.

Introduction: Intravenous immunoglobulin (IVIG) has been widely used to treat the hemolytic disease of the newborn (HDN). Although it has been shown that IVIG treatment reduces the duration of phototherapy and hospitalization, the use of IVIG in hemolytic disease due to ABO incompatibility has been controversial in recent years. This study aimed to investigate the role of IVIG in the prevention of exchange transfusion in infants with ABO HDN who presented with bilirubin levels at or above the level of exchange transfusion. Materials and Methods: This study evaluated the data of infants with ABO HDN in the Turkish Neonatal Jaundice Online Registry. The infants with ABO HDN who met the total serum bilirubin level inclusion criteria (within 2-3 mg/dL of exchange transfusion or even above exchange transfusion level) were included in the study according to the guidelines from the American Academy of Pediatrics and the Turkish Neonatal Society. All patients were managed according to the unit protocols recommended by these guidelines and received light-emitting diode (LED) phototherapy. Infants who only received LED phototherapy, and who received one dose of IVIG with LED phototherapy were compared. Results: During the study period, 531 term infants were included in the study according to inclusion criteria. There were 408 cases in the phototherapy-only group, and 123 cases in the IVIG group. The demographic findings and the mean bilirubin and reticulocyte levels at admission were similar between the groups (p > 0.05), whereas the mean hemoglobin level was slightly lower in the IVIG group (p = 0.037). The mean age at admission was earlier, the need for exchange transfusion was higher, and the duration of phototherapy was longer in the IVIG group (p < 0.001, p = 0.001, and p < 0.001, respectively). The rate of re-hospitalization and acute bilirubin encephalopathy (ABE) was higher in the IVIG group (p < 0.001 and p = 0.01, respectively). Conclusion: In this study, we determined that one dose of IVIG did not prevent an exchange transfusion nor decrease the duration of phototherapy in infants, who had bilirubin levels near or at exchange transfusion level, with hemolytic disease due to ABO incompatibility.

The protective effects of apocynin in hyperoxic lung injury in neonatal rats.

AIM: Inflammation and oxidate stress are significant factors in the pathogenesis of bronchopulmonary dysplasia (BPD). The aim of this study is to investigate the efficacy of apocynin (APO), an anti-inflammatory, antioxidant, and antiapoptotic drug, in the prophylaxis of neonatal hyperoxic lung injury. METHOD: This experimental study included 40 neonatal rats divided into the control, APO, BPD, and BPD + APO groups. The control and APO groups were kept in a normal room environment, while the BPD and BPD + APO groups were kept in a hyperoxic environment. The rats in the APO and BPD + APO groups were administered intraperitoneal APO, while the control and BPD rats were administered ordinary saline. At the end of the trial, lung tissue was evaluated with respect to the degree of histopathological injury, apoptosis, oxidant and antioxidant capacity, and severity of inflammation. RESULT: The BPD and BPD + APO groups exhibited higher mean histopathological injury and alveolar macrophage scores compared to the control and APO groups. Both scores were lower in the BPD + APO group in comparison to the BPD group. The BPD + APO group had a significantly lower average of TUNEL positive cells than the BPD group. The lung tissue examination indicated significantly higher levels of mean malondialdehyde (MDA), total oxidant status (TOS), tumor necrosis factor-α (TNF-α), and interleukin-1ß (IL-1ß) in the BPD group compared to the control and APO groups. While the TNF-α and IL-1ß levels of the BPD + APO group were similar to that of the control group, the MDA and TOS levels were higher compared to the controls and lower compared to the BPD group. The BPD group demonstrated significantly lower levels/activities of mean total antioxidant status, glutathione reductase, superoxide dismutase, glutathione peroxidase in comparison to the control and APO groups. While the mean antioxidant enzyme activity of the BPD + APO group was lower than the control group, it was significantly higher compared to the BPD group. CONCLUSION: This is the first study in the literature to reveal through an experimental neonatal hyperoxic lung injury that APO, an anti-inflammatory, antioxidant, and antiapoptotic drug, exhibits protective properties against the development of BPD.

Does Chrysin prevent severe lung damage in Hyperoxia-Induced lung injury Model?

BACKGROUND: Oxidative stress and inflammation play a critical role in the etiopathogenesis of bronchopulmonary dysplasia (BPD). The aim of this study was to evaluate the preventive effect of Chrysin (CH), an antioxidant, antiinflammatory, antiapoptotic and antifibrotic drug, on hyperoxia-induced lung injury in a neonatal rat model. METHODS: Forty infant rats were divided into four groups labeled the Control, CH, BPD, and BPD + CH. The control and CH groups were kept in a normal room environment, while the BPD and BPD + CH groups were kept in a hyperoxic (90-95%) environment. At the end of the study, lung tissue was evaluated with respect to apoptosis, histopathological damage and alveolar macrophage score as well as oxidant capacity, antioxidant capacity, and inflammation. RESULTS: Compared to the BPD + CH and control groups, the lung tissues of the BPD group displayed substantially higher levels of MDA, TOS, TNF-α, and IL-1ß (p < 0.05). While the BPD + CH group showed similar levels of TNF-α and IL-1ß as the control group, MDA and TOS levels were higher than the control group, and significantly lower than the BPD group (p < 0.05). The BPD group exhibited considerably lower levels of TAS, SOD, GSH, and GSH-Px in comparison to the control group (p < 0.05). The BPD and BPD + CH groups exhibited higher mean scores of histopathological damage and alveolar macrophage when compared to the control and CH groups (p ≤ 0.0001). Both scores were found to be lower in the BPD + CH group in comparison to the BPD group (p ≤ 0.0001). The BPD + CH group demonstrated a significantly lower average of TUNEL and caspase-3 positive cells than the BPD group. CONCLUSION: We found that prophylaxis with CH results in lower histopathological damage score and reduces apoptotic cell count, inflammation and oxidative stress while increasing anti-oxidant capacity.

An observational, prospective, multicenter study on rescue high-frequency oscillatory ventilation in neonates failing with conventional ventilation.

BACKGROUND: To achieve gas exchange goals and mitigate lung injury, infants who fail with conventional ventilation (CV) are generally switched to high-frequency oscillatory ventilation (HFOV). Although preferred in many neonatal intensive care units (NICUs), research on this type of rescue HFOV has not been reported recently. METHODS: An online registry database for a multicenter, prospective study was set to evaluate factors affecting the response of newborn infants to rescue HFOV treatment. The study population consisted of 372 infants with CV failure after at least 4 hours of treatment in 23 participating NICUs. Patients were grouped according to their final outcome as survived (Group S) or as died or received extracorporeal membrane oxygenation (ECMO) (Group D/E). Patients' demographic characteristics and underlying diseases in addition to their ventilator settings, arterial blood gas (ABG) analysis results at 0, 1, 4, and 24 hours, type of device, ventilation duration, and complications were compared between groups. RESULTS: HFOV as rescue treatment was successful in 58.1% of patients. Demographic and treatment parameters were not different between groups, except that infants in Group D/E had lower birthweight (BW) (1655 ± 1091 vs. 1858 ± 1027 g, p = 0.006), a higher initial FiO2 setting (83% vs. 72%, p < 0.001), and a higher rate of nitric oxide exposure (21.8% vs. 11.1%, p = 0.004) in comparison to infants who survived (Group S). The initial cut-offs for a successful response on ABG were defined as pH >7.065 (OR: 19.74, 95% CI 4.83-80.6, p < 0.001), HCO3 >16.35 mmol/L (OR: 1.06, 95% CI 1.01-1.1, p = 0.006), and lactate level <3.75 mmol/L (OR: 1.09%95 CI 1.01-1.16, p = 0.006). Rescue HFOV duration was associated with retinopathy of prematurity (p = 0.005) and moderate or severe chronic lung disease (p < 0.001), but not with patent ductus arteriosus or intraventricular hemorrhage, in survivors (p > 0.05). CONCLUSION: Rescue HFOV as defined for this population was successful in more than half of the patients with CV failure. Although the response was not associated with gestational age, underlying disease, device used, or initial MV settings, it seemed to be more effective in patients with higher BW and those not requiring nitric oxide. Initial pH, HCO3, and lactate levels on ABG may be used as predictors of a response to rescue HFOV.

A Newborn with Gastric Hemangioma Treated Using Propranolol.

Gastric hemangiomas are rare benign vascular tumors that can cause severe gastrointestinal system bleeding. We presented the case of a neonate with fresh bleeding and melena from the orogastric tube and detected gastric hemangioma in esophagogastroduodenoscopic examination. Propranolol is widely used in treatment of cutaneous hemangiomas and non-gastric gastrointestinal system hemangiomas. However, the surgical approach is preferred for treating gastric hemangiomas, and there are few reports of gastric hemangiomas associated with non-surgical treatment. Gastric hemorrhage decreased with antacid and somatostatin treatment. Propranolol treatment was initiated before the surgery decision. After three weeks of treatment, we observed regression in the hemangioma with endoscopic evaluation. During the course of treatment, the patient's gastrointestinal system bleeding did not recur, and there were no side effects associated with propranolol.

Nanostructured Thin Films of Moderately Functionalized PMMA-b-PS.

A library of poly(methyl methacrylate)-block-polystyrene (PMMA-b-PS) block copolymers (BCPs) bearing small amounts (<10 mol%) of functional comonomer in either one or both blocks is investigated for their phase separation behavior in bulk and in thin films. Particularly, functionalities typically involved in modern postpolymerization modifications are considered, e.g., azide, pentafluorophenyl, furfuryl. Small-angle X-ray scattering and atomic force microscopy are employed to determine the characteristic dimensional features of lamellae-forming BCPs, which differ essentially in the functional groups. It is shown that the presence of the reactive moieties does not perturb the ability to phase separate in bulk, yet has an impact on the dimensions of the domains. Using a classic two-step procedure involving surface neutralization with a statistical PMMA-co-PS copolymer, it is observed that some functional copolymers are not able to form homogeneous thin films. Solvent stability and crosslinking ability of the films are then briefly assessed as a first step to establishing the functional films as nanoresolved molecular immobilization platform with feature sizes of 20 nm and below.

Development of severe hyponatremia due to cerebrospinal fluid leakage following meningomyelocele surgery in a newborn.

Cerebrospinal fluid leakage following meningomyelocele surgery is a frequent complication in the wound-healing period and is associated with wound dehiscence. CSF loss can cause severe hyponatremia, especially in the newborn and early infancy periods when dietary sodium content is relatively low. Hyponatremia in the newborn period can result in adverse neurodevelopmental outcomes. In addition, hyponatremia's cerebral effects can increase complications in neurosurgery patients. The authors present the case of a newborn in whom CSF leakage from the operative site and severe hyponatremia developed following meningomyelocele surgery. To the best of their knowledge, severe hyponatremia caused by CSF leakage after meningomyelocele surgery has not been previously reported in the literature.

On the Orthogonality of Two Thiol-Based Modular Ligations.

The chemoselectivity of two thiol-based modular ligations operating under mild conditions is assessed. For this purpose, a macromolecular scaffold possessing allyl and pentafluorophenyl groups in two distinct parts is employed, which enables facile characterization by NMR spectroscopy ((1)H and (19)F) and size-exclusion chromatography. By using appropriate triggers (introduction of a base or light irradiation), it is possible to direct thiols to an arbitrarily chosen part of the scaffold, without any change to the other part and with no involvement of protecting group chemistry. Dual functionalization experiments are achieved by applying these triggers consecutively with no consideration of the reaction sequence order, evidencing full bidirectionality. A set of one-pot, purification-free procedures that enable near-quantitative to full dual functionalization in (very) short reaction times (17-180 min) is also presented.