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1.
Mikrochim Acta ; 191(5): 272, 2024 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-38634999

RESUMEN

A biosensing electrochemical platform for heat shock protein 70 (HSP70) has been developed by integrating a three-electrode indium tin oxide (ITO) on a chip. The platform includes modifications to the reference electrode and working electrode for the detection of HSP70. The new platform is constructed by assembly of HSP70 antibody on PS-AuNPs@Cys/Au indium tin oxide (ITO) electrode to create a high HSP70 sensitive surface. The PS-AuNPs@Cys/Au indium tin oxide (ITO) electrode is obtained by immersing the ITO electrode into the PS-AuNPs@Cys solution and performing constant potential deposition at -1.4 V (Ag/AgCl). The PS-AuNPs@Cys/Au film deposited on ITO glass provides a desirable substrate for the immobilization of the HSP70 antibody and improves the loading of antibody between PS-AuNPs@Cys/Au and the electrode resulting in a significant amplification. Under optimal conditions, the fabricated sensor demonstrates a linear range extending from 0.1 ng mL- 1 to 1000 ng mL- 1, with an impressive detection limit of 25.7 pg mL- 1 (S/N = 3). The developed immunoassay method successfully detected the HSP70 content in normal human blood samples and outperformed the ELISA method commonly used for clinical sample analysis.


Asunto(s)
Oro , Nanopartículas del Metal , Compuestos de Estaño , Humanos , Anticuerpos , Proteínas HSP70 de Choque Térmico
2.
BMC Pediatr ; 24(1): 172, 2024 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-38459440

RESUMEN

BACKGROUND: Necrotizing enterocolitis (NEC) is a serious gastrointestinal disease, primarily affects preterm newborns and occurs after 7 days of life (late-onset NEC, LO-NEC). Unfortunately, over the past several decades, not much progress has been made in its treatment or prevention. This study aimed to analyze the risk factors for LO-NEC, and the impact of LO-NEC on short-term outcomes in very preterm infants (VPIs) with a focus on nutrition and different onset times. METHOD: Clinical data of VPIs were retrospectively collected from 28 hospitals in seven different regions of China from September 2019 to December 2020. A total of 2509 enrolled VPIs were divided into 2 groups: the LO-NEC group and non-LO-NEC group. The LO-NEC group was divided into 2 subgroups based on the onset time: LO-NEC occurring between 8 ~ 14d group and LO-NEC occurring after 14d group. Clinical characteristics, nutritional status, and the short-term clinical outcomes were analyzed and compared among these groups. RESULTS: Compared with the non-LO-NEC group, the LO-NEC group had a higher proportion of anemia, blood transfusion, and invasive mechanical ventilation (IMV) treatments before NEC; the LO-NEC group infants had a longer fasting time, required longer duration to achieve the target total caloric intake (110 kcal/kg) and regain birthweight, and showed slower weight growth velocity; the cumulative dose of the medium-chain and long-chain triglyceride (MCT/LCT) emulsion intake in the first week after birth was higher and breastfeeding rate was lower. Additionally, similar results including a higher proportion of IMV, lower breastfeeding rate, more MCT/LCT emulsion intake, slower growth velocity were also found in the LO-NEC group occurring between 8 ~ 14d when compared to the LO-NEC group occurring after 14 d (all (P < 0.05). After adjustment for the confounding factors, high proportion of breastfeeding were identified as protective factors and long fasting time before NEC were identified as risk factors for LO-NEC; early feeding were identified as protective factors and low gestational age, grade III ~ IV neonatal respiratory distress syndrome (NRDS), high accumulation of the MCT/LCT emulsion in the first week were identified as risk factors for LO-NEC occurring between 8 ~ 14d. Logistic regression analysis showed that LO-NEC was a risk factor for late-onset sepsis, parenteral nutrition-associated cholestasis, metabolic bone disease of prematurity, and extrauterine growth retardation. CONCLUSION: Actively preventing premature birth, standardizing the treatment of grade III ~ IV NRDS, and optimizing enteral and parenteral nutrition strategies may help reduce the risk of LO-NEC, especially those occurring between 8 ~ 14d, which may further ameliorate the short-term clinical outcome of VPIs. TRIAL REGISTRATION: ChiCTR1900023418 (26/05/2019).


Asunto(s)
Enterocolitis Necrotizante , Enfermedades del Prematuro , Síndrome de Dificultad Respiratoria del Recién Nacido , Femenino , Recién Nacido , Humanos , Recien Nacido Prematuro , Estado Nutricional , Enterocolitis Necrotizante/epidemiología , Enterocolitis Necrotizante/etiología , Enterocolitis Necrotizante/prevención & control , Emulsiones , Estudios Retrospectivos , Enfermedades del Prematuro/epidemiología , Enfermedades del Prematuro/etiología , Enfermedades del Prematuro/prevención & control , Factores de Riesgo
3.
Curr Res Struct Biol ; 7: 100122, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38188542

RESUMEN

Over the years, extensive research has highlighted the functional roles of small nucleolar RNAs in various biological processes associated with the development of complex human diseases. Therefore, understanding the existing relationships between different snoRNAs and diseases is crucial for advancing disease diagnosis and treatment. However, classical biological experiments for identifying snoRNA-disease associations are expensive and time-consuming. Therefore, there is an urgent need for cost-effective computational techniques that can enhance the efficiency and accuracy of prediction. While several computational models have already been proposed, many suffer from limitations and suboptimal performance. In this study, we introduced a novel Graph Neural Network-based (GNN) classification model, called SAGESDA, which is implemented through the GraphSAGE architecture with attention for the prediction of snoRNA-disease associations. The classifier leverages local neighbouring nodes in a heterogeneous network to generate new node embeddings through message passing. The mini-batch gradient descent technique was applied to divide the graph into smaller sub-graphs, which enhances the model's accuracy, speed and scalability. With these advancements, SAGESDA attained an area under the receiver operating characteristic (ROC) curve (AUC) of 0.92 using the standard dot product classifier, surpassing previous related studies. This notable performance demonstrates that SAGESDA is a promising model for predicting unknown snoRNA-disease associations with high accuracy. The SAGESDA implementation details can be obtained from https://github.com/momanyibiffon/SAGESDA.git.

4.
Nutrition ; 116: 112221, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37832169

RESUMEN

OBJECTIVE: The aim of this study was to investigate the effects of soybean, medium-chain triacylglycerols (MCTs), olive oil, and fish oil (SMOF) on short-term clinical outcomes, physical growth, and extrauterine growth retardation (EUGR) in very preterm infants. METHODS: This was a multicenter retrospective cohort study of very preterm infants hospitalized in neonatal intensive care units at five tertiary hospitals in China between January 2021 and December 2021. According to the type of fat emulsion used in parenteral nutrition (PN), eligible very preterm infants were divided into the MCTs/long-chain triacylglycerol (MCT/LCT) group and SMOF group. Change in weight z-score (weight Δz) between measurements at birth and at 36 wk of postmenstrual age or at discharge, the incidence of EUGR, and short-term clinical outcomes between the two groups were compared and analyzed. RESULTS: We enrolled 409 very preterm infants, including 205 in the MCT/LCT group and 204 in the SMOF group. Univariate analysis showed that infants in the SMOF group had significantly longer duration of invasive mechanical ventilation and PN, longer days to reach total enteral nutrition, and a higher proportion of maximum weight loss than those in MCT/LCT group (all P < 0.05). After adjusting for the confounding variables, multifactorial logistic regression analysis of short-term clinical outcomes showed that SMOF had protective effects on PN-associated cholestasis (odds ratio [OR], 0.470; 95% confidence interval [CI], 0.266-0.831) and metabolic bone disease of prematurity (OR, 0.263; 95% CI, 0.078-0.880). Additionally, SMOF was an independent risk factor for lower weight growth velocity (ß = -0.733; 95% CI, -1.452 to -0.015) but had no effect on the incidence of EUGR (OR, 1.567; 95% CI, 0.912 to -2.693). CONCLUSION: Compared with MCT/LCT, SMOF can reduce the risk for PN-associated cholestasis and metabolic bone disease of prematurity in very preterm infants and has a negative effect on growth velocity but has no effect on the incidence of EUGR.


Asunto(s)
Enfermedades Óseas Metabólicas , Colestasis , Enfermedades del Prematuro , Lactante , Femenino , Humanos , Recién Nacido , Recien Nacido Prematuro , Emulsiones , Estudios Retrospectivos , Aceite de Soja , Aceites de Pescado , Retardo del Crecimiento Fetal , Enfermedades del Prematuro/epidemiología , Enfermedades del Prematuro/prevención & control , Triglicéridos , Emulsiones Grasas Intravenosas/efectos adversos
6.
Eur J Clin Nutr ; 77(8): 823-832, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37138099

RESUMEN

OBJECTIVE: This study compared the clinical effects of two different lipid emulsions in premature infants with gestational age < 32 weeks (VPI) or birth weight < 1500 g (VLBWI) to provide an evidence-based medicine basis for optimizing intravenous lipid emulsion. METHODS: This was a prospective multicenter randomized controlled study. A total of 465 VPIs or VLBWIs, admitted to the neonatal intensive care unit of five tertiary hospitals in China from March 1, 2021 to December 31, 2021, were recruited. All subjects were randomly allocated into two groups, namely, medium-chain triglycerides/long-chain triglycerides (MCT/LCT) group (n = 231) and soybean oil, medium-chain triglycerides, olive oil, and fish oil (SMOF) group (n = 234). Clinical features, biochemical indexes, nutrition support therapy, and complications were analyzed and compared between the two groups. RESULTS: No significant differences were found in perinatal data, hospitalization, parenteral and enteral nutrition support between the two groups (P > 0.05). Compared with the MCT/LCT group, the incidence of neonates with a peak value of total bilirubin (TB) > 5 mg/dL (84/231 [36.4% vs. 60/234 [25.6%]), a peak value of direct bilirubin (DB) ≥ 2 mg/dL (26/231 [11.3% vs. 14/234 [6.0%]), a peak value of alkaline phosphatase (ALP) > 900 IU/L (17/231 [7.4% vs. 7/234 [3.0%]), and a peak value of triglycerides (TG) > 3.4 mmol/L (13/231 [5.6% vs. 4/234[1.7%]]) were lower in the SMOF group (P < 0.05). Univariate analysis showed that in the subgroup analysis of < 28 weeks, the incidence of parenteral nutrition-associated cholestasis (PNAC) and metabolic bone disease of prematurity (MBDP) were lower in the SMOF group (P = 0.043 and 0.029, respectively), whereas no significant differences were present in the incidence of PNAC and MBDP between the two groups at > 28 weeks group (P = 0.177 and 0.991, respectively). Multivariate logistic regression analysis revealed that the incidence of PNAC (aRR: 0.38, 95% confidence interval [CI]: 0.20-0.70, P = 0.002) and MBDP (aRR: 0.12, 95% CI: 0.19-0.81, P = 0.029) in the SMOF group were lower than that in the MCT/LCT group. In addition, no significant differences were recorded in the incidence of patent ductus arteriosus, feeding intolerance, necrotizing enterocolitis (Bell's stage ≥ 2), late-onset sepsis, bronchopulmonary dysplasia, intraventricular hemorrhage, periventricular leukomalacia, retinopathy of prematurity and extrauterine growth retardation between the two groups (P > 0.05). CONCLUSIONS: The application of mixed oil emulsion in VPI or VLBWI can reduce the risk of plasma TB > 5 mg/dL, DB ≥ 2 mg/dL, ALP > 900 IU/L, and TG > 3.4 mmol/L during hospitalization. SMOF has better lipid tolerance, reduces the incidence of PNAC and MBDP, and exerts more benefits in preterm infants with gestational age < 28 weeks.


Asunto(s)
Colestasis , Recien Nacido Prematuro , Recién Nacido , Humanos , Estudios Prospectivos , Emulsiones Grasas Intravenosas/efectos adversos , Aceite de Soja/efectos adversos , Aceite de Oliva , Aceites de Pescado , Colestasis/etiología , Triglicéridos , Bilirrubina , Recién Nacido de muy Bajo Peso
7.
BMC Pediatr ; 23(1): 250, 2023 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-37210514

RESUMEN

BACKGROUND: It is proposed that the development of parenteral nutrition-associated cholestasis (PNAC) was significantly associated with preterm birth, low birth weight, infection, etc.; however, the etiology and pathogenesis of PNAC are not fully understood. Most of the studies examining PNAC-associated risk factors were single-center studies with relatively small sample sizes. OBJECTIVE: To analyze the risk factors associated with PNAC in preterm infants in China. METHODS: This is a retrospective multicenter observational study. Clinical data on the effect of multiple oil-fat emulsions (soybean oil-medium chain triglycerides-olive oil-fish oil, SMOF) in preterm infants were collected from a prospective multicenter randomized controlled study. A secondary analysis was performed in which preterm infants were divided into the PNAC group and the non-PNAC group based on the PNAC status. RESULTS: A total of 465 cases very preterm infants or very low birth weight infants were included in the study in which 81 cases were assigned to the PNAC group and 384 cases were assigned to the non-PNAC group. The PNAC group had a lower mean gestational age, lower mean birth weight, longer duration of invasive and non-invasive mechanical ventilation, a longer duration oxygen support, and longer hospital stay (P < 0.001 for all). The PNAC group had higher respiratory distress syndrome, hemodynamically significant patent ductus arteriosus, necrotizing enterocolitis (NEC) with stage II or higher, surgically treated NEC, late-onset sepsis, metabolic bone disease, and extrauterine growth retardation (EUGR) compared to the non-PNAC group (P < 0.05 for all). In contrast with the non-PNAC group, the PNAC group received a higher maximum dose of amino acids and fat emulsion, more medium/long-chain fatty emulsion, less SMOF, had a longer duration of parenteral nutrition, lower rates of breastfeeding, higher incidence of feeding intolerance (FI), more accumulated days to achieve total enteral nutrition, less accumulated days of total calories up to standard 110 kcal/kg/day and slower velocity of weight growth (P < 0.05 for all). Logistic regression analysis indicated that the maximum dose of amino acids (OR, 5.352; 95% CI, 2.355 to 12.161), EUGR (OR, 2.396; 95% CI, 1.255 to 4.572), FI (OR, 2.581; 95% CI, 1.395 to 4.775), surgically treated NEC (OR, 11.300; 95% CI, 2.127 ~ 60.035), and longer total hospital stay (OR, 1.030; 95% CI, 1.014 to 1.046) were independent risk factors for the development of PNAC. SMOF (OR, 0.358; 95% CI, 0.193 to 0.663) and breastfeeding (OR, 0.297; 95% CI, 0.157 to 0.559) were protective factors for PNAC. CONCLUSIONS: PNAC can be reduced by optimizing the management of enteral and parenteral nutrition and reducing gastrointestinal comorbidities in preterm infants.


Asunto(s)
Colestasis , Nacimiento Prematuro , Femenino , Recién Nacido , Humanos , Recien Nacido Prematuro , Emulsiones/química , Peso al Nacer , Estudios Prospectivos , Nacimiento Prematuro/etiología , Colestasis/etiología , Colestasis/epidemiología , Nutrición Parenteral/efectos adversos , Recién Nacido de muy Bajo Peso , Aminoácidos , Factores de Riesgo
8.
Appl Microbiol Biotechnol ; 107(7-8): 2351-2361, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36881116

RESUMEN

Biocatalytic transformations in organic synthesis often require the use of organic solvents to improve substrate solubility and promote the product formation. Halohydrin dehalogenases (HHDHs) are enzymes that catalyze the formation and conversion of epoxides, important synthetic class of compounds that are often sparingly soluble in water and prone to hydrolysis. In this study, the activity, stability, and enantioselectivity of HHDH from Agrobacterium radiobacter AD1 (HheC) in form of cell-free extract were evaluated in various aqueous-organic media. A correlation was discovered between the enzyme activity in the ring-closure reaction and logP of the solvent. Knowledge of such a relationship makes biocatalysis with organic solvents more predictable, which may reduce the need to experiment with a variety of solvents in the future. The results revealed a high enzyme compatibility with hydrophobic solvents (e.g., n-heptane) in terms of activity and stability. Regarding the HHDH applicability in an organic medium, inhibitions by a number of solvents (e.g., THF, toluene, chloroform) proved to be a more challenging problem than the protein stability, especially in the ring-opening reaction, thus suggesting which solvents should be avoided. In addition, solvent tolerance of the thermostable variant ISM-4 was also evaluated, revealing increased stability and to a lesser extent enantioselectivity compared to the wild-type. This is the first time such a systematic analysis has been reported, giving insight into the behavior of HHDHs in nonconventional media and opening new opportunities for the future biocatalytic applications. KEY POINTS: • HheC performs better in the presence of hydrophobic than hydrophilic solvents. • Enzyme activity in the PNSHH ring-closure reaction is a function of the logP. • Thermostability of ISM-4 variant is accompanied by superior solvent tolerance.


Asunto(s)
Agrobacterium tumefaciens , Hidrolasas , Hidrolasas/metabolismo , Solventes , Hidrólisis , Agrobacterium tumefaciens/metabolismo
9.
Ital J Pediatr ; 49(1): 14, 2023 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-36698176

RESUMEN

BACKGROUND: Infants with rule-out infections are responsible for the majority of empirical antibiotics treatment (EAT) in neonatal intensive care units (NICUs), particularly very preterm infants (VPIs). Antibiotic overuse has been linked to adverse outcomes. There is a paucity of data on the association between EAT and clinical outcomes (containing the nutritional outcomes) of VPIs without infection-related morbidities. METHODS: Clinical data of VPIs admitted in 28 hospitals in 20 provinces of China from September 2019 to December 2020 were collected. EAT of VPIs was calculated as the number of days with initial usage in the first week after birth, and then categorized into 3 groups (antibiotic exposure: none, 1-4 days, and > 4 days). Clinical characteristics, nutritional status , and the short-term clinical outcomes among 3 groups were compared and analyzed. RESULTS: In total, 1834 VPIs without infection-related morbidities in the first postnatal week were enrolled, including 152 cases (8.3%) without antibiotics, 374 cases (20.4%) with EAT ≤4 days and 1308 cases (71.3%) with EAT > 4 days. After adjusting for the confounding variables, longer duration of EAT was associated with decreased weight growth velocity and increased duration of reach of full enteral feeding in EAT > 4 days group (aß: -4.83, 95% CI: - 6.12 ~ - 3.53; aß: 2.77, 95% CI: 0.25 ~ 5.87, respectively) than those receiving no antibiotics. In addition, the risk of feeding intolerance (FI) in EAT > 4 days group was 4 times higher than that in non-antibiotic group (aOR: 4.14, 95%CI: 1.49 ~ 13.56) and 1.8 times higher than that in EAT ≤4 days group (aOR: 1.82, 95%CI: 1.08 ~ 3.17). EAT > 4 days was also a risk factor for greater than or equal to stage 2 necrotizing enterocolitis (NEC) than those who did not receive antibiotics (aOR: 7.68, 95%CI: 1.14 ~ 54.75) and those who received EAT ≤4 days antibiotics (aOR: 5.42, 95%CI: 1.94 ~ 14.80). CONCLUSIONS: The EAT rate among uninfected VPIs was high in Chinese NICUs. Prolonged antibiotic exposure was associated with decreased weight growth velocity, longer duration of reach of full enteral feeding, increased risk of feeding intolerance and NEC ≥ stage 2. Future stewardship interventions to reduce EAT use should be designed and implemented.


Asunto(s)
Enterocolitis Necrotizante , Enfermedades del Prematuro , Lactante , Recién Nacido , Humanos , Recien Nacido Prematuro , Recién Nacido de muy Bajo Peso , Antibacterianos/uso terapéutico , Unidades de Cuidado Intensivo Neonatal , Enfermedades del Prematuro/etiología , Enterocolitis Necrotizante/complicaciones
11.
Org Biomol Chem ; 20(48): 9734-9741, 2022 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-36440739

RESUMEN

Ten different fluorinated aromatic epoxides have been tested as potential substrates for halohydrin dehalogenase (HHDH) HheC. The majority of investigated epoxides are useful building blocks in synthetic chemistry applications, with a number of them being polysubstituted. Moderate to high enantioselectivities (ER = 15 → 200) were observed in azidolysis, allowing the synthesis of enantioenriched (R)-azido alcohols containing fluorine in the molecule. In the case where a reaction runs over 50% conversion, enantiopure (S)-epoxides are also available. While o-F-styrene oxide was easily converted into a product, a sterically challenging o-CF3-derivative was not accepted by HheC. In silico probing of the binding site indicates that, in order to accommodate an o-CF3-derivative in the HheC active site, it is necessary to eliminate steric hindrance. Hence, we extended our research by probing several available HheC variants containing relevant modifications in the active site. The active mutant P84V/F86P/T134A/N176A (named HheC-M4) was identified, showing not only high activity towards o-CF3-styrene oxide, but also inverted enantioselectivity (ES = 27). Since (S)-enantioselective HHDHs are rare and therefore valuable for their synthetic application, this enzyme was screened on the initial panel of substrates. The observed (S)-enantioselectivity (ES = 1-111) is ascribed to the formation of the additional space by introduced mutations in HheC-M4, which is also confirmed by classical MD simulations. Successive molecular docking demonstrated that this newly formed tunnel located close to the protein surface is a critical feature of HheC-M4, representing a novel binding site.


Asunto(s)
Compuestos Epoxi , Hidrolasas , Simulación del Acoplamiento Molecular , Hidrolasas/metabolismo , Compuestos Epoxi/química , Biocatálisis , Dominio Catalítico , Estereoisomerismo
12.
World J Stem Cells ; 14(9): 729-743, 2022 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-36188114

RESUMEN

BACKGROUND: Recent studies have demonstrated that mesenchymal stem cells (MSCs) can rescue injured target cells via mitochondrial transfer. However, it has not been fully understood how bone marrow-derived MSCs repair glomeruli in diabetic kidney disease (DKD). AIM: To explore the mitochondrial transfer involved in the rescue of injured glomerular endothelial cells (GECs) by MSCs, both in vitro and in vivo. METHODS: In vitro experiments were performed to investigate the effect of co-culture with MSCs on high glucose-induced GECs. The transfer of mitochondria was visua lized using fluorescent microscopy. GECs were freshly sorted and ultimately tested for apoptosis, viability, mRNA expression by real-time reverse transcri ptase-polymerase chain reaction, protein expression by western blot, and mitochondrial function. Moreover, streptozotocin-induced DKD rats were infused with MSCs, and renal function and oxidative stress were detected with an automatic biochemical analyzer and related-detection kits after 2 wk. Kidney histology was analyzed by hematoxylin and eosin, periodic acid-Schiff, and immunohistochemical staining. RESULTS: Fluorescence imaging confirmed that MSCs transferred mitochondria to injured GECs when co-cultured in vitro. We found that the apoptosis, proliferation, and mitochondrial function of injured GECs were improved following co-culture. Additionally, MSCs decreased pro-inflammatory cytokines [interleukin (IL)-6, IL-1ß, and tumor necrosis factor-α] and pro-apoptotic factors (caspase 3 and Bax). Mitochondrial transfer also enhanced the expression of superoxide dismutase 2, B cell lymphoma-2, glutathione peroxidase (GPx) 3, and mitofusin 2 and inhibited reactive oxygen species (ROS) and dynamin-related protein 1 expression. Furthermore, MSCs significantly ameliorated functional parameters (blood urea nitrogen and serum creatinine) and decreased the production of malondialdehyde, advanced glycation end products, and ROS, whereas they increased the levels of GPx and superoxide dismutase in vivo. In addition, significant reductions in the glomerular basement membrane and renal interstitial fibrosis were observed following MSC treatment. CONCLUSION: MSCs can rejuvenate damaged GECs via mitochondrial transfer. Additionally, the improvement of renal function and pathological changes in DKD by MSCs may be related to the mechanism of mitochondrial transfer.

13.
Int J Mol Sci ; 23(17)2022 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-36077513

RESUMEN

Thermophilic proteins have various practical applications in theoretical research and in industry. In recent years, the demand for thermophilic proteins on an industrial scale has been increasing; therefore, the engineering of thermophilic proteins has become a hot direction in the field of protein engineering. However, the exact mechanism of thermostability of proteins is not yet known, for engineering thermophilic proteins knowing the basis of thermostability is necessary. In order to understand the basis of the thermostability in proteins, we have made a statistical analysis of the sequences, secondary structures, hydrogen bonds, salt bridges, DHA (Donor-Hydrogen-Accepter) angles, and bond lengths of ten pairs of thermophilic proteins and their non-thermophilic orthologous. Our findings suggest that polar amino acids contribute to thermostability in proteins by forming hydrogen bonds and salt bridges which provide resistance against protein denaturation. Short bond length and a wider DHA angle provide greater bond stability in thermophilic proteins. Moreover, the increased frequency of aromatic amino acids in thermophilic proteins contributes to thermal stability by forming more aromatic interactions. Additionally, the coil, helix, and loop in the secondary structure also contribute to thermostability.


Asunto(s)
Aminoácidos , Proteínas , Aminoácidos/química , Enlace de Hidrógeno , Desnaturalización Proteica , Ingeniería de Proteínas , Proteínas/química , Temperatura
14.
Environ Res ; 212(Pt D): 113472, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35577005

RESUMEN

Ideonella sakaiensis PET hydrolase (IsPETase) is a well-characterized enzyme for effective PET biodegradation. However, the low soluble expression level of the enzyme hampers its practical implementation in the biodegradation of PET. Herein, the expression of IsPETaseMut, one of the most active mutants of IsPETase obtained so far, was systematically explored in E. coli by adopting a series of strategies. A notable improvement of soluble IsPETaseMut was observed by using chaperon co-expression and fusion expression systems. Under the optimized conditions, GroEL/ES co-expression system yielded 75 ± 3.4 mg·L-1 purified soluble IsPETaseMut (GroEL/ES), and NusA fusion expression system yielded 80 ± 3.7 mg·L-1 purified soluble NusA-IsPETaseMut, which are 12.5- and 4.6-fold, respectively, higher than its commonly expression in E. coli. The two purified enzymes were further characterized. The results showed that IsPETaseMut (GroEL/ES) displayed the same catalytic behavior as IsPETaseMut, while the fusion of NusA conferred new enzymatic properties to IsPETaseMut. Although NusA-IsPETaseMut displayed a lower initial hydrolysis capacity than IsPETaseMut, it showed a 1.4-fold higher adsorption constant toward PET. Moreover, the product inhibition effect of terephthalic acid (TPA) on IsPETase was reduced with NusA-IsPETaseMut. Taken together, the latter two catalytic properties of NusA-IsPETaseMut are more likely to contribute to the enhanced product release by NusA-IsPETaseMut PET degradation for two weeks.


Asunto(s)
Burkholderiales , Proteínas de Escherichia coli , Burkholderiales/genética , Burkholderiales/metabolismo , Escherichia coli/genética , Cinética , Tereftalatos Polietilenos/metabolismo , Factores de Elongación Transcripcional/metabolismo
15.
Front Microbiol ; 13: 790063, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35273581

RESUMEN

Thermophilic proteins have important application value in biotechnology and industrial processes. The correct identification of thermophilic proteins provides important information for the application of these proteins in engineering. The identification method of thermophilic proteins based on biochemistry is laborious, time-consuming, and high cost. Therefore, there is an urgent need for a fast and accurate method to identify thermophilic proteins. Considering this urgency, we constructed a reliable benchmark dataset containing 1,368 thermophilic and 1,443 non-thermophilic proteins. A multi-layer perceptron (MLP) model based on a multi-feature fusion strategy was proposed to discriminate thermophilic proteins from non-thermophilic proteins. On independent data set, the proposed model could achieve an accuracy of 96.26%, which demonstrates that the model has a good application prospect. In order to use the model conveniently, a user-friendly software package called iThermo was established and can be freely accessed at http://lin-group.cn/server/iThermo/index.html. The high accuracy of the model and the practicability of the developed software package indicate that this study can accelerate the discovery and engineering application of thermally stable proteins.

16.
Clin Lab ; 68(2)2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-35142187

RESUMEN

BACKGROUND: To explore the correlation between left atrial thrombosis and peripheral blood neutrophil-to-lymphocyte ratio (NLR) in patients with non-valvular atrial fibrillation (NVAF). METHODS: A total of 207 NVAF patients treated from March 2016 to August 2020 were divided into low and high NLR groups. Their clinical data were compared, and the correlations of NLR with clinical indicators and left atrial thrombosis were analyzed. The influencing factors for left atrial thrombosis and their predictive values were investigated. RESULTS: CHADS2 score, CHA2DS2-VASc score, NLR, D-dimer (D-D), serum uric acid (SUA), brain natriuretic peptide (BNP), C-reactive protein (CRP), left atrial dimension (LAD) and ratio of early mitral diastolic flow peak value to early diastolic mitral annular velocity (E/Em) increased, while left atrial ejection fraction (LAEF) decreased in high NLR group compared with those in low NLR group (p < 0.05). NLR was significantly positively correlated with the CHADS2 score, CHA2DS2-VASc score, D-D, SUA, BNP, CRP, LAD and E/Em, and significantly negatively correlated with LAEF (p < 0.0001). Left atrial thrombosis had positive correlations with CHADS2 score, CHA2DS2-VASc score, NLR, D-D, SUA, BNP, CRP, LAD and E/Em, and negative correlation with LAEF (p = 0.000). CHA2DS2-VASc score, NLR, D-D and LAD were risk factors for left atrial thrombosis (p < 0.05). The optimal cut-off value was 1.85 when the area under the curve of NLR for predicting left atrial thrombosis in the case of NVAF was 0.806 [95% confidence interval (CI): 0.746 - 0.865], the sensitivity was 74.82% (95% CI: 0.668 -0.818) and the specificity was 67.65% (95% CI: 0.552 - 0.785). CONCLUSIONS: The increase of NLR prominently elevates the risk of left atrial thrombosis in NVAF patients, and NLR was an independent risk factor, with certain predictive value.


Asunto(s)
Fibrilación Atrial , Trombosis , Fibrilación Atrial/diagnóstico , Humanos , Linfocitos , Neutrófilos , Estudios Retrospectivos , Medición de Riesgo , Trombosis/diagnóstico , Ácido Úrico
17.
Female Pelvic Med Reconstr Surg ; 28(5): 304-310, 2022 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-34593685

RESUMEN

OBJECTIVES: The purpose of this study was to evaluate the relationship between blood glucose level and the prevalence and frequency of stress urinary incontinence (SUI) in women. METHODS: We conducted a cross-sectional study of female participants in the National Health and Nutrition Examination Survey database between 2007 and 2016. Dose-response analysis curves and univariate and multivariate logistic regressions were used to determine the relationship between blood glucose level and the prevalence and frequency of SUI. RESULTS: A total of 10,771 participants were included in this study, of which 6,466 (60.0%) reported no SUI, 4,305 (31.1%) reported monthly SUI, and 953 (8.8%) reported weekly SUI. We found that the blood glucose levels were higher in the weekly SUI group than in the monthly SUI and no SUI groups. Based on blood glucose levels, participants were divided into 3 groups: ≤86.0 mg/dL group, >86.0 to 98.0 mg/dL group, and >98.0 mg/dL group. Dose-response curves showed a nonlinear positive correlation between blood glucose levels and the prevalence and extent of SUI, and participants in the glucose >98.0 mg/dL group had a 15.2% higher risk (adjusted odds risk, 1.152; 95% confidence interval, 1.027-1.293; P = 0.016) of SUI prevalence and 12.5% higher risk (adjusted odds risk 1.125; 95% confidence interval, 1.009-1.255; P = 0.034) of SUI frequency than participants in the glucose ≤86.0 mg/dL group. CONCLUSIONS: We found that the prevalence and frequency of SUI in women were positively correlated with blood glucose levels, and these findings warrant further study and application to clinical practice to control SUI in women.


Asunto(s)
Incontinencia Urinaria de Esfuerzo , Glucemia , Estudios Transversales , Femenino , Humanos , Masculino , Encuestas Nutricionales , Prevalencia , Incontinencia Urinaria de Esfuerzo/epidemiología
19.
Front Neurol ; 13: 993985, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36742049

RESUMEN

Objective: To investigate the protective effect of high-proportion breast milk feeding (>50%) on intraventricular hemorrhage (IVH) in very preterm infants (VPIs). Methods: This was a retrospective secondary analysis of a prospective multi-center study, which included 604 VPIs from six hospitals in eastern China between September 2019 and December 2020. The 604 VPIs were divided into two groups according to whether IVH occurred. High-proportion breast milk feeding was defined as breast milk accounting for 51-100% of the total feeding amount both within 7 days and throughout the hospitalization. The IVH grades and the rate of high-proportion breast milk feeding were analyzed. Furthermore, to explore the relationship between high-proportion breast milk feeding and IVH grading, the VPIs' general information, perinatal factors, growth, and nutritional status during hospitalization, and related complications were compared between the two groups. Results: High-proportion breast milk feeding was reported in 63.41% of the VPIs. Furthermore, IVH grades I-II and III-IV were noted in 39.73% (240/604) and 1.66% (10/604) of the VPIs, respectively. Univariate analysis revealed that IVH occurrence in VPIs is influenced by perinatal factors, invasive respiratory therapy, high-proportion breast milk feeding, start feeding with breast milk, the cumulative amount of early parenteral nutrition, postnatal complications, physical growth, and other factors (P < 0.05). After adjustments for gestational age, birth weight, and possible influencing factors through binary logistic regression analysis, the results revealed that high-proportion breast milk feeding and and start feeding with breast milk were associated with a lower total incidence of IVH. Further stratification showed that high-proportion breast milk feeding was associated with a lower incidence of grade I-II IVH. Similarly, after adjusting for the same factors, breast milk feeding >50% in the 1st week was associated with a decreased incidence of total IVH and further stratification showed that it was associated with a lower incidence of grade I-II IVH. Conclusion: High-proportion breast milk feeding and breast milk feeding more than 50% of total intake during the 1st week might be protective factors for IVH grade I-II in VPIs, which further verified the neuroprotective effect of breast milk. In clinical practice, the construction of breast milk banks should be strengthened, breast milk feeding should be encouraged in neonatal intensive care units, and efforts should be made to increase breast milk feeding rates to improve the outcomes of VPIs.

20.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 52(6): 960-965, 2021 Nov.
Artículo en Chino | MEDLINE | ID: mdl-34841762

RESUMEN

OBJECTIVE: To explore the effect of nuclear factor-erythroid 2-related factor (Nrf2) pathway activation on hippocampal neuron damage in neonatal rats with bilirubin encephalopathy. METHODS: Neonatal rats were randomly assigned to a control group (Control), a model group (Model) and an Nrf2 activator TBHQ (tert-Butylhydroquinone) group (TBHQ), with 20 rats in each group. Bilirubin solution was injected through the cerebellomedullary cistern to establish the neonatal rat model of bilirubin encephalopathy. Neurobehavioral changes were observed in rats and the water content of the brain tissue was measured. Nissl staining was done to observe the damage of hippocampal neurons. TUNEL staining was used to observe the apoptosis of hippocampal neurons. Colorimetric analysis was done to determine the Caspase-3 activity in the hippocampus. The content of malondialdehyde (MDA) and reduced glutathione (GSH) and the activity of superoxide dismutase (SOD) in the hippocampus were examined by chemical analysis. qRT-PCR and Western blot were done to measure the expression of Nrf2 and heme oxygenase-l (HO-1) mRNA and proteins in the hippocampus. RESULTS: After injection of bilirubin into the cerebellomedullary cistern, the young rats in the Model group and the TBHQ group showed different degrees of neurological abnormalities, while those in the control group showed no significant neurobehavioral abnormalities. Compared with the Control group, the Model group had severe neuronal damage, and the water content of brain tissue, the apoptosis of hippocampal neurons, the activity of Caspase-3 and the content of MDA content significantly increased ( P<0.01), while the SOD activity, GSH content, the expression of Nrf2 and HO-1 mRNA and proteins significantly decreased ( P<0.05). Compared with the Model group, neuronal damage was improved in the TBHQ group, and the water content of brain tissue, apoptosis of hippocampal neurons, activity of Caspase-3 and MDA content were all significantly reduced ( P<0.01), while SOD activity, GSH content and the expression of Nrf2 and HO-1 mRNA and proteins were significantly increased ( P<0.05). CONCLUSION: Activation of the Nrf2 pathway can improve hippocampal neuronal damage in neonatal rats with bilirubin encephalopathy and inhibit neuronal apoptosis and the oxidation reaction.


Asunto(s)
Kernicterus , Factor 2 Relacionado con NF-E2 , Animales , Animales Recién Nacidos , Hipocampo , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Neuronas/metabolismo , Estrés Oxidativo , Ratas , Transducción de Señal
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