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Coumarin N-acylhydrazone derivatives were synthesized in the reaction of 3-acetylcoumarin and different benzohydrazides in the presence of molecular iodine as catalyst and at room temperature. All reactions were rapidly completed, and products were obtained in good to excellent yields. It is important to emphasize that four products were reported for the first time in this study. The obtained compounds were subjected to evaluation of their in vitro antioxidative activity using DPPH, ABTS, and FRAP methods. It was shown that products with a catechol moiety in their structure are the most potent antioxidant agents. The thermodynamic parameters and Gibbs free energies of reactions were used to determine the most probable mechanism of action. The results of in silico examination emphasize the need to take solvent polarity and free radical species into account when examining antiradical action. It was discovered by using computational approaches that HAT and SPLET are competitive molecular pathways for the radical scavenging activity of all compounds in polar mediums, while the HAT is the dominant mechanism in non-polar environments.

Free radicals often interact with vital proteins, violating their structure and inhibiting their activity. In previous studies, synthesis, characterisation, and the antioxidative properties of the five different coumarin derivatives have been investigated. In the tests of potential toxicity, all compounds exhibited low toxicity with significant antioxidative potential at the same time. In this paper, the radical scavenging activity of the abovementioned coumarin derivatives towards ten different radical species was investigated. It was found that all investigated compounds show good radical scavenging ability, with results that are in correlation with the results published in the previous study. Three additional mechanisms of radical scavenging activity were investigated. It was found that all three mechanisms are thermodynamically plausible and in competition. Interestingly, it was found that products of the Double Hydrogen Atom Transfer (DHAT) mechanism, a biradical species in triplet spin state, are in some cases more stable than singlet spin state analogues. This unexpected trend can be explained by spin delocalisation over the hydrazide bridge and phenolic part of the molecule with a low probability of spin pairing. Besides radical-scavenging activity, the pharmacokinetic and drug-likeness of the coumarin hybrids were investigated. It was found that they exhibit good membrane and skin permeability and potential interactions with P-450 enzymes. Furthermore, it was found that investigated compounds satisfy all criteria of the drug-likeness tests, suggesting they possess a good preference for being used as potential drugs.

Background and Objectives: The COVID-19 pandemic has led to significant changes globally, which has also affected patients with type 1 diabetes mellitus (T1DM). This study aimed to determine the incidence of T1DM and the characteristics of diabetic ketoacidosis (DKA) during the pandemic comparing it to pre-pandemic period. Materials and Methods: Data from patients <19 years with newly diagnosed T1DM between 1st January 2017 and 31st December 2021 from four regional centers in Vojvodina were retrospectively collected and analyzed. Results: In 2021, the highest incidence of T1DM in the last five years was recorded, 17.3/100,000. During the pandemic period (2020−2021), there were 99 new-onset T1DM, of which 42.4% presented in DKA, which is significantly higher than in the pre-pandemic period (34.1%). During the pandemic, symptom duration of T1DM lasted significantly longer than before the COVID-19 period. At the age of 10−14 years, the highest incidence of T1DM and COVID-19, the highest frequency rate of DKA, and severe DKA were observed. Conclusions: The pandemic is associated with a high incidence rate of T1DM, longer duration of symptoms of T1DM, a high frequency of DKA, and a severe DKA at diagnosis. Patients aged 10−14 years are a risk group for the occurrence of T1DM with severe clinical presentation. Additional studies are needed with a longer study period and in a wider geographical area, with data on exposure to COVID-19 infection, the permanence of new-onset T1DM, and the psychosocial impact of the pandemic.

Background: Neonatal acute kidney injury (AKI) is common and is associated with poor outcomes. New criteria for the diagnosis of AKI were introduced based on the increase in serum creatinine (SCr) levels and/or reduction of urine output (UOP). Yet, there is no generally accepted opinion so far, which criteria (whether SCr, UOP, or their combination) are the most appropriate to diagnose neonatal AKI., Methods: The retrospective study included 195 prematurely born neonates who fulfilled all inclusion criteria (with at least two SCr measurements). In all the neonates included in the study, AKI was diagnosed using three different definitions: (1) SCr criteria (an increase in SCr values of ≥0.3 mg/dl), (2) UOP criteria (UOP < 1.5 ml/kg/h), and (3) SCr + UOP criteria., Results: Out of all of the patients the study included, 85 (44%) were diagnosed with AKI. The neonates who had AKI had a significantly lower gestational age, birth weight, and Apgar score, longer duration of mechanical ventilation, and a higher mortality rate. SCr + UOP criteria showed higher sensitivity for prediction of death compared to SCr or UOP alone (p = 0.0008, 95% CI 0.040-0.154, and p = 0.0038, 95% CI 0.024-0.125, respectively). If only SCr or only UOP criterion are used, they fail to identify AKI in 61 and 67%, respectively. AKI was an independent risk factor for death (OR 7.4875; CI 3.1887-17.5816)., Conclusions: Similar to other studies, our data showed that neonates with AKI have worse outcome. Neonatal AKI defined based on SCr + UOP criteria is a better predictor of death than neonatal AKI defined based only on the SCr or UOP criteria. Also, by using SCr + UOP criteria for diagnosing neonatal AKI, more patients with AKI are recruited than when only one of those criteria is used.

Background: The factors that contribute to the development of acute kidney injury (AKI) and treatment outcome among prematurely born neonates are not clearly understood., Methods: This retrospective study included 150 prematurely born neonates. AKI was defined as an increase of serum creatinine levels ≥0.3 mg/dl compared to basal values., Results: The majority of neonates with AKI (94.8 %) had a body weight <1,500 g. Logistic regression analysis showed that the Apgar score in the 5th minute <5, serum lactate levels >5 on the first day of life, core body temperature <36 ºC on the first day of life, occurrence of sepsis, intracranial hemorrhage, necrotizing enterocolitis, patent ductus arteriosus, as well as a treatment with vancomycin or dopamine were independent risk factors for the development of AKI. After the groups of neonates with and without AKI were adjusted, the calculated risk ratio for a negative outcome of treatment (death) was 2.215 (CI 1.27-3.86) for neonates with AKI. Neonates with AKI had higher serum sodium levels in the third and fourth days of life., Conclusions: AKI is associated with high mortality in preterm neonates. It is very important to identify, as quickly as possible, all infants who are at high risk of developing AKI.

Acute renal failure (ARF) is a severe complication of acute CO poisoning which, combined with other organ lesions, may result in lethal outcome. In all vague cases of ARF with nontraumatic rhabdomyolysis, CO poisoning should be considered as a possible etiologic factor. The diagnosis is made on the basis of several simple laboratory tests: determination of carboxyhemoglobin concentration, demonstration of myoglobin in urine or pigment granulated cylindres in urinary sediment, positive orthotoluidine test, and high CPK values originating from skeletal musculature. Many authors report on excellent prognosis in ARF due to nontraumatic rhabdomyolysis of various causes. Our case report shows that the prognosis of CO poisoned patient greatly depends on timely and appropriate treatment, severity of damage to other organs, and success of the treatment of complications such as hospital infections.