Computer-made peptide RQ18 acts as a dual antifungal and antibiofilm peptide though membrane-associated mechanisms of action.

The spread of fungi resistant to conventional drugs has become a threatening problem. In this context, antimicrobial peptides (AMPs) have been considered as one of the main alternatives for controlling fungal infections. Here, we report the antifungal and antibiofilm activity and some clues about peptide RQ18's mechanism of action against Candida and Cryptococcus. This peptide inhibited yeast growth from 2.5 µM and killed all Candida tropicalis cells within 2 h incubation. Moreover, it showed a synergistic effect with antifungal agent the amphotericin b. RQ18 reduced biofilm formation and promoted C. tropicalis mature biofilms eradication. RQ18's mechanism of action involves fungal cell membrane damage, which was confirmed by the results of RQ18 in the presence of free ergosterol in the medium and fluorescence microscopy by Sytox green. No toxic effects were observed in murine macrophage cell lines and Galleria mellonella larvae, suggesting fungal target selectivity. Therefore, peptide RQ18 represents a promising strategy as a dual antifungal and antibiofilm agent that contributes to infection control without damaging mammalian cells.

Hepatic venous reconstruction of the left lateral segment with emphasis on anomalous hepatic vein in pediatric liver transplantation.

Left lateral segment grafts have become a suitable option in pediatric liver transplantation (PLT). The correlation between hepatic vein (HV) reconstruction and outcome is relevant when assessing the safe use of these grafts. We retrospectively reviewed the medical records prospectively collected from a pediatric living donor liver transplantation database and conducted a comparative analysis of the different left lateral segment graft types according to HV reconstruction. Donor, recipient, and intraoperative variables were analyzed. Post-transplant outcomes included vascular complications such as hepatic vein outflow obstruction, early (≤30 d) and late (>30 d) PVT, hepatic artery thrombosis, and graft survival. From February 2017 to August 2021, 303 PLTs were performed. According to venous anatomy, the distribution of the left lateral segment was as follows: single HV (type I) in 174 (57.4%), close HVs, simple venoplasty for reconstruction (type II) in 97 (32.01%), anomalous hepatic vein (AHV) with a distance between the HVs orifices that allowed simple venoplasty (type IIIA) in 25 (8.26%) and AHV with a distance between the HVs orifices requiring homologous venous graft interposition (type IIIB) in 07 (2.31%) grafts. Type IIIB grafts came from male donors ( p =0.04) and had a higher mean donor height ( p =0.008), a higher mean graft weight, and a higher graft-to-recipient weight ratio, both p =0.002. The median follow-up time was 41.4 months. The overall cumulative graft survival was 96.3%, and comparative graft survival showed no difference (log-rank p =0.61). No hepatic vein outflow obstructions were observed in this cohort study. There was no statistically significant difference in the post-transplant outcomes between the graft types. The venous reconstruction of the AHV with homologous venous graft interposition had similar outcomes in the short and long term.

In vitro immunogenic profile of recombinant SARS-CoV2 S1-RBD peptide in murine macrophage and microglial cells.

BACKGROUND: The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants can infect common mice inducing significant pathological lung lesions and inflammatory responses. This substantially mimics coronavirus disease 19 (COVID-19) infection and pathogenesis in humans. OBJECTIVES: To characterise the effects of recombinant SARS-CoV-2 S1 receptor-binding domain (RBD) peptide in murine macrophage and microglial cells' immune activation compared with classical PAMPs in vitro. METHODS: Murine RAW 264.7 macrophages and BV2 microglial cells were exposed to increasing concentrations of the RBD peptide (0.01, 0.05, and 0.1 µg/mL), Lipopolysaccharide (LPS) and Poly(I:C) and evaluated after two and 24 h for significant markers of macrophage activation. We determined the effects of RBD peptide on cell viability, cleaved caspase 3 expressions, and nuclear morphometry analysis. FINDINGS: In RAW cells, RBD peptide was cytotoxic, but not for BV2 cells. RAW cells presented increased arginase activity and IL-10 production; however, BV2 cells expressed iNOS and IL-6 after RBD peptide exposure. In addition, RAW cells increased cleaved-caspase-3, apoptosis, and mitotic catastrophe after RBD peptide stimulation but not BV2 cells. CONCLUSION: RBD peptide exposure has different effects depending on the cell line, exposure time, and concentration. This study brings new evidence about the immunogenic profile of RBD in macrophage and microglial cells, advancing the understanding of SARS-Cov2 immuno- and neuropathology.

Investigating Effects of IR-780 in Animal Models of B16-F10 Melanoma: New Approach in Lung Metastasis.

IR-780 is a fluorescent marker, photostable and non-toxic, and is widely used in tumor targeting; however, studies on the impact of IR-780 in animal models of B16-F10 melanoma are scarce in the literature. Therefore, this study aims to analyze behavior of this marker in melanoma cells using in vitro and in vivo analyses with fluorescence microscopy to conduct an analysis of cell culture, and an in vivo imaging system for an analysis of cell culture, tumor targeting on animals, and organ examination. In vitro analysis showed that B16-F10 cells at a concentration of 2 × 105 cells.plate-1 allowed a better visualization using 20 µM of IR-780. Furthermore, the location of IR-780 accumulation was confirmed by its fluorescence microscopy. Through in vivo studies, fluorescence was not observed in subcutaneous nodules, and it was found that animals that received intraperitoneal injection of B16-F10 cells presented ascites and did not absorb IR-780. Additionally, animals exhibiting lung metastasis showed fluorescence in ex vivo lung images. Therefore, use of the IR-780 marker for evaluating the progression of tumor growth did not demonstrate efficiency; however, it was effective in diagnosing pulmonary metastatic tumors. Although this marker presented limitations, results of evaluating pulmonary involvement through ex vivo fluorescence imaging were determined based on intensity of fluorescence.

Effect of levodopa/carbidopa on stress response in zebrafish.

The dopaminergic system of zebrafish is complex and the numerous pathways and receptors in the central nervous system (CNS) are being extensively studied. A critical factor for the synthesis, activation and release of catecholamines (CAs) is the presence of tyrosine hydroxylase, an enzyme which converts L-tyrosine into levodopa. Levodopa thus is the intermediary in the synthesis of dopamine (DA) and norepinephrine (NE) and promotes its release; therefore, CAs play an important role in the CNS with hormonal functions. Here, we use levodopa/carbidopa to clarify the involvement of the dopaminergic pathway in the stress response in zebrafish submitted to an acute stress challenge. Acute stress was induced by chasing fish with a net for 2 min and assessed by measuring whole-body cortisol levels. Two experiments were carried out, the first with exposure to levodopa/carbidopa and the second with exposure to AMPT and levodopa/carbidopa. Levodopa/carbidopa balances the stress response through its action on the zebrafish hypothalamic-pituitary-adrenal (HPA) axis. Changes in cortisol levels suggest that DA was related to the balance of the stress response and that NE decreased this response. These effects were specific to stress since levodopa/carbidopa did not induce changes in cortisol in non-stressed fish.

Effects of purslane supplementation on C-reactive protein levels and biomarkers of oxidative stress as marks for metabolic syndrome: A systematic review and meta-analysis of randomized controlled trials.

The antioxidant and antiinflammatory properties of purslane (Portulaca oleracea L.) are known in preclinical studies but further examination is needed to expand their potential into the clinical scenario. A systematic review and meta-analysis of randomized controlled trials were performed to elucidate the effects of purslane supplementation on C-reactive protein (CRP) levels and biomarkers of oxidative stress in metabolic syndrome, its related complications, and other diseases. PubMed/MEDLINE, Web of Science, SCOPUS, and Embase were the databases searched. Heterogeneity was examined using the I-squared (I2 ) statistic, in which the source of heterogeneity was determined if the I2 -value was >50%. After all the screening processes, 10 studies met the eligibility criteria and were analyzed. Following purslane supplementation, CRP levels decreased significantly (weighted mean difference [WMD]: -0.33 mg/dl, 95% confidence interval [CI]: -0.66, -0.004, p = .047) but with significant heterogeneity (I2  = 87.4%, p = .001). Purslane supplementation did not significantly change serum levels of malondialdehyde (MDA) (WMD: -0.353 µm/L; 95% CI: -0.920, 0.213; I2  = 50.7%), total antioxidant capacity (TAC) (WMD: 0.090 mm/L, 95% CI: -0.081, 0.262; I2  = 47.1%), and superoxide dismutase (SOD) (WMD: 6.54 U/ml, 95% CI: -22.150, 35.236; I2  = 70.7%). Thus, this meta-analysis showed a positive effect of purslane supplementation as a tool to decrease CRP levels, but not to MDA, TAC, and SOD levels.

Pool-based exercise for amelioration of pain in adults with fibromyalgia syndrome: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the effects of pool-based exercises on pain symptomatology among adults with fibromyalgia syndrome. METHODS: A systematic review and meta-analysis were carried out using PRISMA guidelines. Database search was conducted by two independent reviewers. For meta-analysis, the visual analogue scale (VAS) score for pain was used as the primary outcome and the Fibromyalgia Impact Questionnaire (FIQ) score was utilized as the secondary outcome. RESULTS: A total of 42 out of 292 potentially eligible studies were selected for being read in full by reviewers, 14 of which were included in meta-analysis, being 10 of them used in sensitivity analysis of either the primary or secondary outcome. Data pooled from 10 randomized controlled trials (n = 508) revealed that patients who underwent pool-based exercises exhibited a significantly lower mean in VAS score as compared to controls (SMD = -0.27, 95% CI: -0.45 to -0.09). Regarding FIQ scores, data from 10 randomized controlled trials were pooled (n = 578) and a lower mean score was also shown in the group that underwent a pool-based exercise program (SMD = -0.29, 95% CI: -0.49 to -0.09). Limitations of this study include the small sample size and moderate dropout rates in currently available clinical trials. CONCLUSION: Pool-based exercise may provide some additional benefit for pain relief in adults with fibromyalgia as compared to either land-based or no physical exercise. IMPLICATIONS OF KEY FINDINGS: Collectively, these findings suggest that pool-based exercise deserves further attention as a potential adjuvant therapeutic option for adults with fibromyalgia. PROSPERO registration number: CRD42019136755.

Development of a novel anti-biofilm peptide derived from profilin of Spodoptera frugiperda.

Candida yeast infections are the fourth leading cause of death worldwide. Peptides with antimicrobial activity are a promising alternative treatment for such infections. Here, the antifungal activity of a new antimicrobial peptide-PEP-IA18-was evaluated against Candida species. PEP-IA18 was designed from the primary sequence of profilin, a protein from Spodoptera frugiperda, and displayed potent activity against Candida albicans and Candida tropicalis, showing a minimum inhibitory concentration (MIC) of 2.5 µM. Furthermore, the mechanism of action of PEP-IA18 involved interaction with the cell membrane (ergosterol complexation). Treatment at MIC and/or 10 × MIC significantly reduced biofilm formation and viability. PEP-IA18 showed low toxicity toward human fibroblasts and only revealed hemolytic activity at high concentrations. Thus, PEP-IA18 exhibited antifungal and anti-biofilm properties with potential applicability in the treatment of infections caused by Candida species.

Biochemical characterization of a Kunitz inhibitor from Inga edulis seeds with antifungal activity against Candida spp.

We describe the characterization of IETI, the first trypsin inhibitor purified from Inga edulis, a tree widely distributed in Brazil. Two-step chromatography was used to purify IETI, a protein composed of a single peptide chain of 19,685.10 Da. Amino-terminal sequencing revealed that IETI shows homology with the Kunitz family, as substantiated by its physical-chemical features, such as its thermal (up to 70 °C) and wide-range pH stability (from 2 to 10), and the value of its dissociation constant (6.2 nM). IETI contains a single reactive site for trypsin, maintained by a disulfide bridge; in the presence of DTT, its inhibitory activity was reduced in a time- and concentration-dependent manner. IETI presented activity against Candida ssp., including C. buinensis and C. tropicalis. IETI inhibitory activity triggered yeast membrane permeability, affecting cell viability, thus providing support for the use of IETI in further studies for the control of fungal infections.

Postexercise Hypotension Is Volume-Dependent in Hypertensives: Autonomic and Forearm Blood Responses.

de Freitas Brito, A, Brasileiro Santos, MdS, Coutinho de Oliveira, CV, and da Cruz Santos, A. Postexercise hypotension is volume-dependent in hypertensives: autonomic and forearm blood responses. J Strength Cond Res 33(1): 234-241, 2019-The purpose of this study was to evaluate the effect of 2 sessions of resistance exercise (RE) with different volumes on postexercise hypotension (PEH), forearm blood flow (FBF), and cardiac autonomic balance (LF/HF) in hypertensive elderly woman. The study was conducted with 16 hypertensive elderly (25.7 ± 3 kg·m², 55.5 ± 3 years) subjected to 3 experimental sessions, i.e., a control session, exercise with a set (S1), and exercise with 3 sets (S3). For each session, the subjects were evaluated before and after intervention. In the preintervention period, blood pressure (BP), FBF, and LF/HF were measured after 10 minutes of rest in the supine position. Thereafter, the subjects were taken to the gym to perform their exercise sessions or remained at rest during the same period. Both S1 and S3 comprised a set of ten repetitions of 10 exercises, with an interval of 90 seconds between exercises. Subsequently, the measurements were again performed at 10, 30, 50, 70, and 90 minutes of recovery (postintervention) in the supine position. Postexercise hypotension (systolic/diastolic) was greater in S3 than in S1 (-26 ± 4/-14 ± 5 mm Hg vs. -18 ± 5/-8 ± 5 mm Hg, p ≤ 0.05). Similarly, FBF and cardiac LF/HF increased in both sessions, being more evident in S3 than in S1 (4.98 ± 0.32 vs. 4.36 ± 0.27 ml·min·100 ml, p ≤ 0.05; and LF/HF = 1.69 ± 0.225 vs. 1.37 ± 0.13 p ≤ 0.05, respectively). We conclude that a single RE session with 3 series were able to promote higher PEH in hypertensive women, and this phenomenon was accompanied by increased FBF and increased cardiac autonomic activity.

Dual Insecticidal Effects of Adenanthera pavonina Kunitz-Type Inhibitor on Plodia interpunctella is Mediated by Digestive Enzymes Inhibition and Chitin-Binding Properties.

The Indianmeal moth, Plodia interpunctella, is one of the most damaging pests of stored products. We investigated the insecticidal properties of ApKTI, a Kunitz trypsin inhibitor from Adenanthera pavonina seeds, against P. interpunctella larvae through bioassays with artificial diet. ApKTI-fed larvae showed reduction of up to 88% on larval weight and 75% in survival. Trypsin enzymes extracted from P. interpunctella larvae were inhibited by ApKTI, which also demonstrated capacity to bind to chitin. Kinetic studies revealed a non-competitive inhibition mechanism of ApKTI for trypsin, which were further corroborated by molecular docking studies. Furthermore, we have demonstrated that ApKTI exhibits a hydrophobic pocket near the reactive site loop probably involved in chitin interactions. Taken together, these data suggested that the insecticidal activity of ApKTI for P. interpunctella larvae involves a dual and promiscuous mechanisms biding to two completely different targets. Both processes might impair the P. interpunctella larval digestive process, leading to larvae death before reaching the pupal stage. Further studies are encouraged using ApKTI as a biotechnological tool to control insect pests in field conditions.

Inga laurina trypsin inhibitor (ILTI) obstructs Spodoptera frugiperda trypsins expressed during adaptive mechanisms against plant protease inhibitors.

Plant protease inhibitors (PIs) are elements of a common plant defense mechanism induced in response to herbivores. The fall armyworm, Spodoptera frugiperda, a highly polyphagous lepidopteran pest, responds to various PIs in its diet by expressing genes encoding trypsins. This raises the question of whether the PI-induced trypsins are also inhibited by other PIs, which we posed as the hypothesis that Inga laurina trypsin inhibitor (ILTI) inhibits PI-induced trypsins in S. frugiperda. In the process of testing our hypothesis, we compared its properties with those of selected PIs, soybean Kunitz trypsin inhibitor (SKTI), Inga vera trypsin inhibitor (IVTI), Adenanthera pavonina trypsin inhibitor (ApTI), and Entada acaciifolia trypsin inhibitor (EATI). We report that ILTI is more effective in inhibiting the induced S. frugiperda trypsins than SKTI and the other PIs, which supports our hypothesis. ILTI may be more appropriate than SKTI for studies regarding adaptive mechanisms to dietary PIs.

α-Methyltyrosine, a tyrosine hydroxylase inhibitor, decreases stress response in zebrafish (Danio rerio).

In this article, we show that the tyrosine hydroxylase inhibitor α-Methyl-l-tyrosine (AMPT) decreased the responsiveness of the zebrafish stress axis to an acute stressful challenge. These effects were specific for responses to stimulation, since unstimulated (basal) cortisol levels were not altered by AMPT. Moreover, AMPT decreased the stress response 15min after stimulation, but not after that time period. To our knowledge, this is the first report about the effects of AMPT on the neuroendocrine axis of adult zebrafish in acute stress responses. Overall, these results suggest a mechanism of catecholamine-glucocorticoid interplay in neuroendocrine responses of fish, pointing an interesting avenue for physiological research, as well as an important endpoint that can be disrupted by environmental contamination. Further experiments will unravel the mechanisms by which AMPT blocked the cortisol response.

A chitin-binding lectin from Moringa oleifera seeds (WSMoL) impairs the digestive physiology of the Mediterranean flour larvae, Anagasta kuehniella.

Biotechnological techniques allow the investigation of alternatives to outdated chemical insecticides for crop protection; some investigations have focused on the identification of molecules tailored from nature for this purpose. We, herein, describe the negative effects of water-soluble lectin from Moringa oleifera seeds (WSMoL) on Anagasta kuehniella development. The chitin-binding lectin, WSMoL, impaired the larval weight gain by 50% and affected the activity of the pest's major digestive enzymes. The commitment of the digestive process became evident after controlled digestion studies, where the capacity of protein digestion was compromised by >90%. Upon acute exposure, the lectin was not resistant to digestion; however, chronic ingestion of WSMoL was able to reverse this feature. Thus, we show that resistance to digestion may not be a prerequisite for a lectin's ability to exert negative effects on larval physiology. The mechanism of action of WSMoL involves binding to chitin with possible disruption to the peritrophic membrane, causing disorder between the endo- and ectoperitrophic spaces. Additionally, results suggest that WSMoL may trigger apoptosis in gut cells, leading to the lower enzymatic activity observed in WSMoL-fed larvae. Although assays employing an artificial diet did not demonstrate effects of WSMoL on A. kuehniella mortality, this lectin may hold potential for exerting insecticide effects on other pest insects, as well for use in other experimental approaches, such as WSMoL-expressing plants. Moreover, the use of WSMoL with other biotechnological tools, such as 'pyramid' crops, may represent a strategy for delaying the evolution of pest resistance to transgenic crops, since its multiple site targets could act in synergism with other insecticide compounds.

Supplementation with Watermelon Extract Reduces Total Cholesterol and LDL Cholesterol in Adults with Dyslipidemia under the Influence of the MTHFR C677T Polymorphism.

Dyslipidemia and genetic polymorphisms are associated with increased risk for developing cardiovascular diseases, and watermelon appears to have the potential to improve hyperlipidemia due to the presence of nutrients such as arginine and citrulline. OBJECTIVE: To test the hypolipidemic effect of watermelon extract (Citrullus lanatus) and the influence of the methylenetetrahydrofolate reductase genotype (MTHFR C677T) on supplementation response. METHODS: This is an experimental clinical phase II randomized and double-blind study. Forty-three subjects with dyslipidemia were randomly divided into 2 groups: experimental (n = 22) and control (n = 21) groups. The subjects were supplemented daily for 42 days with 6 g of watermelon extract or a mixture of carbohydrates (sucrose/glucose/fructose). RESULTS: The use of watermelon extract reduced plasma total cholesterol (p < 0.05) and low-density lipoprotein (p < 0.01) without modifying triglycerides, high-density lipoprotein, and very low-density lipoprotein values. Only carriers of the T allele (MTHFR C677T) showed decreasing concentrations of low-density lipoprotein (p < 0.01). No changes in anthropometric parameters analyzed were observed. This is the first study to demonstrate the beneficial effect of the consumption of watermelon extract in reducing plasma levels of lipids in humans. The MTHFR C677T polymorphism did not affect the plasma lipid concentration but made individuals more responsive to treatment with watermelon. CONCLUSIONS: The consumption of this functional food represents an alternative therapy in the combined treatment of patients with dyslipidemia, promoting health and minimizing the development of risk factors for cardiovascular diseases.

Purification and characterization of a Kunitz inhibitor from Poincianella pyramidalis with insecticide activity against the Mediterranean flour moth.

This paper describes the characterization of a trypsin inhibitor from Poincianella pyramidalis seeds (PpyTI). The partial sequencing of PpyTI revealed homology to Kunitz inhibitors, clustered as a member of Family I03 in MEROPS database. PpyTI has a single polypeptide chain of 19,042 Da and presents stability at high temperatures (up to 70 °C) and a wide range of pH. In vitro assays showed that disulfide bridges have an important stabilization role of reactive site in PpyTI, a characteristic shared among several Kunitz inhibitors. Bioassays carried out with the Mediterranean flour moth (Anagasta kuehniella) revealed a significant decrease in both larval weight and survival of PpyTI-fed larvae, besides a larval stage extension. Through biochemical analysis, we demonstrated that the PpyTI insecticide effects were triggered by digestion process commitment, through the inhibition of trypsin and chymotrypsin activities, the major digestive enzymes in this species. The insecticide effects and biochemical characterization of PpyTI encourage further studies using this inhibitor for insect pest control.

High-Intensity Resistance Exercise Promotes Postexercise Hypotension Greater than Moderate Intensity and Affects Cardiac Autonomic Responses in Women Who Are Hypertensive.

The purpose of this study was to evaluate the effect of high-intensity resistance exercise (RE) sessions on blood pressure (BP), heart rate (HR), cardiac autonomic modulation, and forearm blood flow (FBF). Sixteen trained hypertensive women (n = 16, 56 ± 3 years) completed the following 3 experimental sessions: control (CS), RE at 50% (EX50%), and RE at 80% (EX80%) of 1 repetition maximum (1RM). Both EX50% and EX80% comprised a set of 10 repetitions of 10 exercises, with an interval of 90 seconds between exercises. Measurements were taken preintervention and postintervention (at 10, 30, 50, 70, and 90 minutes of recovery). Reductions in systolic/diastolic BP after exercise were greater in EX80% (largest declines, -29 ± 4/-14 ± 5 mm Hg) than EX50% (largest declines, -18 ± 6/-8 ± 5 mm Hg, p ≤ 0.05). Heart rate and cardiac sympathovagal balance (LF/HF) increased more in relation to pre-exercise values in EX80% than EX50% (largest increases 96 ± 3 vs. 90 ± 4 b·min, LF/HF = 1.77 ± 0.25 vs. 1.40 ± 0.20, respectively, p ≤ 0.05). Increases in FBF and hyperemia was also higher in EX80% than EX50% compared with pre-exercise (4.97 ± 0.28 vs. 4.36 ± 0.27 ml·min·100 ml and 5.90 ± 0.20 vs. 5.38 ± 0.25 ml·min·100 ml; p ≤ 0.05, respectively). These results suggest that RE of higher intensity promoted greater postexercise hypotension accompanied by greater increases in FBF, vasodilator response, HR, and cardiac sympathovagal balance.

The trypsin inhibitor from Entada acaciifolia seeds affects negatively the development of Mediterranean flour moth, Anagasta kuehniella.

The Mediterranean flour moth (Anagasta kuehniella) is a pest insect that attacks stored foods. The difficulty in controlling this kind of pest promotes the development of alternatives for pest control, among them the use of proteins with insecticide effect. In this work, we evaluated the role of a trypsin inhibitor purified from Entada acaciifolia seeds (EATI) on the A. kuehniella development. Different concentrations of inhibitor were added to a diet to determine its effects on insect performance. At 0.4%, the EATI decreases the larval weight and survival rates by 54.6% and 15%, respectively; in addition to the extension of the life cycle of insect. The biochemical analysis showed that the inhibitor is refractory to the digestion by midgut proteases, and led to a reduction of 32% in general proteolytic activity. A detailed analysis of the enzymatic activity revealed a decrease of 50% in trypsin activity as the chymotrypsin activity increased by 12%; possibly to compensate the commitment of the digestive process. The trypsins from the EATI-fed group stayed sensitive to the inhibition by EATI, and based on kinetic assays no new trypsin enzymes were produced as adaptation attempt. The insecticides effects observed for the EATI against this pest encourage a more in depth study of its possible long-term use as a biotechnological tool.

Challenges in clinical identification of right ventricular dysfunction in preterm infants with persistent pulmonary hypertension of the newborn.

BACKGROUND: Right ventricular dysfunction, typically qualitatively diagnosed (Q-RVd) in preterm infants, requires echocardiography which is not always acutely available. We aimed to identify clinical indices of Q-RVd in very preterm infants (gestational age, GA <32 weeks) with persistent pulmonary hypertension of newborn (PPHN) and examine the reliability and validity of Q-RVd. METHODS: Forty-seven infants with mean ± SD GA of 26.8 ± 2.7 weeks who had targeted neonatal echocardiography (TNE) ≤72 h old, during PPHN, were retrospectively studied. Three standard TNE clips were reviewed by two blinded assessors, and infants categorized as Q-RVd if moderate-severe RVd was diagnosed on ≥2 clips. Cardiopulmonary clinical indices at TNE and quantitative RV functional markers were compared between Q-RVd vs. no-RVd groups. Potential quantitative RVd definitions examined by classifying each measurement as "low" or "normal" using published data. Inter-rater agreement for Q-RVd assessed using Kappa statistics. RESULTS: Mean age at TNE was 25.3 ± 20.4 h with Q-RVd diagnosed in 19(40 %) infants. Q-RVd group demonstrated higher peak oxygen requirements (96 ± 9 % vs. 84 ± 16 %, p < 0.01); however, no clinical parameters at TNE differentiated the groups. Quantitative measures were lower in Q-RVd patients, confirming classification validity. Among tested quantitative definitions, low RV stroke volume was associated with lower systolic blood pressure (41±7 vs. 47±9 mmHg, p = 0.02) and higher shock index (4.02±0.80 vs. 3.44±0.72, p = 0.02). Kappa for Q-RVd was 0.55 (95%CI 0.32-0.77). CONCLUSIONS: The non-specific nature of clinical markers of RVd in preterm infants with PPHN necessitates echocardiographic diagnosis of RVd. Studies should examine prognostic relevance of RVd and establish outcome-based quantitative definitions in preterm infants.

Pharmacokinetics and pharmacodynamics of intravenous dexmedetomidine (2 µg∙kg-1) in dogs.

This study assessed the pharmacokinetics and pharmacodynamics of low-dose dexmedetomidine after IV bolus in dogs. Six healthy adult dogs (6.8 ± 3.0 kg) received dexmedetomidine (2 µg.kg-1 IV) over 2 min, using an infusion pump. Blood samples were collected totaling 5 h of monitoring. A validated UHPLC-MS/MS method was used to determine the plasma concentration of dexemedetomidine. For pharmacodynamics, HR, RR, oscillometric MBP, Grint END sedation score were evaluated at baseline (T0), every 3 min (T3 to T21), and after 30 (T30) and 60 (T60) minutes, with p < 0.05. T1/2 was 28.28 ± 6.14 min; the area under the curve was 467.44 ± 60.42 ng/mL/min. The total clearance was 5.46 ± 0.41 mL/min/kg, the Vdss was 146.19 ± 21.04 mL/kg, and the C max was 3.13 ± 1.15 ng/mL. HR (bpm) decreased significantly from T6 (79 ± 21) to T21 (78 ± 31) compared to T0 (116 ± 28). RR(mpm) decreased from T3 (43 ± 44) to T60 (41 ± 23), with T0 being 70 ± 48. The MBP (mmHg) increased at T18 (151 ± 34), T21 (152 ± 35), and T30 (140 ± 27), compared to T0 (111 ± 22). Sedation occurred at all times post-bolus, with a maximum peak at T12 (END 8 ± 6). The low dose of dexmedetomidine provided sedation in all animals, characterizing rapid metabolization and elimination. However, cardiovascular effects still may have negative repercussions in dogs with hemodynamic comorbidities, highlighting the caution and individualization of its use in certain patients.