Activity and stability of immobilized Candida rugosa lipase on chitosan coated Fe3O4 nanoparticles in aqueous and organic media

Fe3O4 (magnetite) nanoparticles were prepared by coprecipitation method, coated by chitosan and functionalized by glutaraldehyde. Lipase enzyme from Candida rugosa was immobilized on the prepared particles via cross linking reaction. Synthesis steps and characterization were examined by XRD, TEM, and FTIR.  The immobilization conditions were 10 mL of phosphate buffer (0.1 M, pH 6.5) containing 30 mg of  functionalized magnetic chitosan nanoparticles and 2.0 mg·mL-1 of lipase, immobilization temperature of 4 ℃ and immobilization time of 1 h. Under these conditions, lipase was successfully immobilized with loading capacity of 87 mg/g. The immobilized enzyme showed good operational and storage stability, where it remained stable after 30 days of storage at 4â—¦C.and retained about 61% of its initial activity after twenty repeated uses. Finally enzymatic catalyze synthesis of butyl and hexyl oleate at 40 â—¦C with shaking (200 rpm) was realized in n-hexane and confirmed by GC analysis

Synthesis and anti-mycobacterial evaluation of some new isonicotinylhydrazide analogues

AbstractThe synthesis of some new 3,4-disubstituted thiazolylideneisonicotinohydrazide derivatives 3a–k, 2-substituted thiazolidinylisonicotinamide derivatives 4a–d and pyrrolylisonicotinamide derivatives 5, 6 and 7 is described. The resulted compounds are evaluated for their in vitro antitubercular activity. The minimum inhibitory concentration (MIC) of compound 3g showed comparable in vitro activity to isoniazid against Mycobacterium tuberculosis H37Ra 7131 strain in concentration 9.77μg/mL

Study of DNA methyl transferase 3A mutation in acute myeloid leukemic patients

Background: Recent studies have shown that somatic mutations in DNA methyltransferase (DNMT3A) might affect the prognosis of AML.Objective: The aim of this work was to investigate the frequency and prognostic impact of the most frequent mutation of DNMT3A, R882H mutation in AML using simple and rapid molecular techniques.Patients and methods: We have used allele-specific blocker (ASB-PCR) and endonuclease restriction for the detection of DNMT3A R882H mutation in 56 adult patients with AML.Results: DNMT3A R882H mutation was detected in 7/56 (12.5%) of patients. R882H mutation positive patients were older compared to the wild-type AML (p = 0.08). No association was found with initial laboratory parameters including white blood cells (WBC), hemoglobin (HGB) and Bone marrow (BM) blasts (p > 0.05). Thirty-two patients (57.1%) achieved complete remission (CR), 11/56 (19.6%) died before day 28 induction death (ID) and 13/56 (23.2%) had resistant disease (RD). DNMT3A R882H positive patients were not different regarding the response to induction chemotherapy (CR) compared to the negative group (wild-type) (p > 0.05). Median follow-up period for all patients was 1.6 months, Overall survival (OS) was 65%, and the median was 9.89 months. OS of DNMT3A positive patients was not statistically significant compared to wild-type patients (p = 0.09). Disease free survival (DFS) was 54.6% for all patients, with no difference between wild and mutants (0.59) patients.Conclusion: DNMT3A R882H is a frequent mutation in adult de novo AML. The frequency of the mutation tends to increase with age. The two methods used in the study are easy to interpret and are recommended for rapid detection of the mutation required for risk stratification.Keywords: AML, DNMT3A, ASB-PCR, PCR-RFLP, Endonuclease restrictio

Day-to-day physical activity producing low gravitational impacts is associated with faster visual processing speed at age 69: cross-sectional study

Background Little is known about how different physical activity (PA) parameters relate to cognitive function in older adults. Using accelerometers calibrated to detect vertical impacts from ground reaction forces we examined the associations of low, medium and higher impact PA with processing speed, verbal memory and cognitive state in older adults. Methods Participants were 69-year old British men and women from the Medical Research Council National Survey of Health and Development included in a vertical impacts and bone sub-study (n = 558; 48.2% female). Counts of low (0.5 < g < 1.0 g), medium (1 < g < 1.5 g), or higher (≥1.5 g) magnitude impacts were derived from vertical acceleration peaks recorded over 7 days by hip-worn accelerometers. Processing speed was assessed by a timed visual letter search task, verbal memory by a 15-word list learning test and cognitive state by the Addenbrooke’s Cognitive Examination (ACE-III). Potential confounders were childhood cognitive ability, adult socioeconomic position, body mass index and depression. Results In initial sex-adjusted models, low magnitude impacts were associated with better performance in all three cognitive function tests; standard deviation differences in test scores per doubling in number of low impacts: letter search speed = 0.10 (95% confidence intervals (CI): 0.03 to 0.16), word learning test = 0.05 (95% CI: 0.00 to 0.11), ACE-III scale = 0.09 (95% CI: 0.03 to 0.14). After adjustment for confounders, differences persisted for letter search speed (0.09; 95% CI: 0.02 to 0.16) but were closer to the null for the word learning test (0.02; 95% CI: − 0.04 to 0.07) and ACE-III scores (0.04; 95% CI: − 0.01 to 0.09). Low impacts remained associated with letter search speed after sensitivity analyses excluding those with functional and musculoskeletal problems, and after adjustment for impacts in higher bands. Modest positive associations between higher magnitude impacts and cognitive test scores were most likely due to chance. Conclusion Accelerometer-derived low impact physical activity was associated with better visual processing speed in 69-year old men and women independently of childhood cognitive ability and other measured confounders. Day-to-day low impact physical activity may therefore have the potential to benefit cognitive health in older adults

Using linear and natural cubic splines, SITAR, and latent trajectory models to characterise nonlinear longitudinal growth trajectories in cohort studies

BACKGROUND: Longitudinal data analysis can improve our understanding of the influences on health trajectories across the life-course. There are a variety of statistical models which can be used, and their fitting and interpretation can be complex, particularly where there is a nonlinear trajectory. Our aim was to provide an accessible guide along with applied examples to using four sophisticated modelling procedures for describing nonlinear growth trajectories. METHODS: This expository paper provides an illustrative guide to summarising nonlinear growth trajectories for repeatedly measured continuous outcomes using (i) linear spline and (ii) natural cubic spline linear mixed-effects (LME) models, (iii) Super Imposition by Translation and Rotation (SITAR) nonlinear mixed effects models, and (iv) latent trajectory models. The underlying model for each approach, their similarities and differences, and their advantages and disadvantages are described. Their application and correct interpretation of their results is illustrated by analysing repeated bone mass measures to characterise bone growth patterns and their sex differences in three cohort studies from the UK, USA, and Canada comprising 8500 individuals and 37,000 measurements from ages 5–40 years. Recommendations for choosing a modelling approach are provided along with a discussion and signposting on further modelling extensions for analysing trajectory exposures and outcomes, and multiple cohorts. RESULTS: Linear and natural cubic spline LME models and SITAR provided similar summary of the mean bone growth trajectory and growth velocity, and the sex differences in growth patterns. Growth velocity (in grams/year) peaked during adolescence, and peaked earlier in females than males e.g., mean age at peak bone mineral content accrual from multicohort SITAR models was 12.2 years in females and 13.9 years in males. Latent trajectory models (with trajectory shapes estimated using a natural cubic spline) identified up to four subgroups of individuals with distinct trajectories throughout adolescence. CONCLUSIONS: LME models with linear and natural cubic splines, SITAR, and latent trajectory models are useful for describing nonlinear growth trajectories, and these methods can be adapted for other complex traits. Choice of method depends on the research aims, complexity of the trajectory, and available data. Scripts and synthetic datasets are provided for readers to replicate trajectory modelling and visualisation using the R statistical computing software. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12874-022-01542-8

Hip and spine bone mineral density are greater in master sprinters, but not endurance runners compared with non-athletic controls

Summary: We examined bone density in older athletes and controls. Sprinters had greater hip and spine bone density than endurance athletes and controls, whereas values were similar in the latter two groups. These results could not be explained by differences in impact, muscle size or power between sprint and endurance athletes. Purpose: We examined the relationship between prolonged participation in regular sprint or endurance running and skeletal health at key clinical sites in older age, and the factors responsible for any associations which we observed. Methods: We recruited 38 master sprint runners (28 males, 10 females, mean age 71 ± 7 years), 149 master endurance runners (111 males, 38 females, mean age 70 ± 6 years) and 59 non-athletic controls (29 males, 30 females, mean age 74 ± 5 years). Dual X-ray absorptiometry was used to assess hip and spine bone mineral density (BMD), body composition (lean and fat mass), whilst jump power was assessed with jumping mechanography. In athletes, vertical impacts were recorded over 7 days from a waist-worn accelerometer, and details of starting age, age-graded performance and training hours were recorded. Results: In ANOVA models adjusted for sex, age, height, body composition, and jump power, sprinter hip BMD was 10 and 14% greater than that of endurance runners and controls respectively. Sprinter spine BMD was also greater than that of both endurance runners and controls. There were no differences in hip or spine BMD between endurance runners and controls. Stepwise regression showed only discipline (sprint/endurance), sex, and age as predictors of athlete spine BMD, whilst these variables and starting age were predictive of hip BMD. Conclusions: Regular running is associated with greater BMD at the fracture-prone hip and spine sites in master sprinters but not endurance runners. These benefits cannot be explained by indicators of mechanical loading measured in this study including vertical impacts, body composition or muscular output

Exposure to natural environments during pregnancy and birth outcomes in 11 european birth cohorts

Research suggests that maternal exposure to natural environments (i.e., green and blue spaces) promotes healthy fetal growth. However, the available evidence is heterogeneous across regions, with very few studies on the effects of blue spaces. This study evaluated associations between maternal exposure to natural environments and birth outcomes in 11 birth cohorts across nine European countries. This study, part of the LifeCycle project, was based on a total sample size of 69,683 newborns with harmonised data. For each participant, we calculated seven indicators of residential exposure to natural environments: surrounding greenspace in 100m, 300m, and 500m using Normalised Difference Vegetation Index (NDVI) buffers, distance to the nearest green space, accessibility to green space, distance to the nearest blue space, and accessibility to blue space. Measures of birth weight and small for gestational age (SGA) were extracted from hospital records. We used pooled linear and logistic regression models to estimate associations between exposure to the natural environment and birth outcomes, controlling for the relevant covariates. We evaluated the potential effect modification by socioeconomic status (SES) and region of Europe and the influence of ambient air pollution on the associations. In the pooled analyses, residential surrounding greenspace in 100m, 300m, and 500m buffer was associated with increased birth weight and lower odds for SGA. Higher residential distance to green space was associated with lower birth weight and higher odds for SGA. We observed close to null associations for accessibility to green space and exposure to blue space. We found stronger estimated magnitudes for those participants with lower educational levels, from more deprived areas, and living in the northern European region. Our associations did not change notably after adjustment for air pollution. These findings may support implementing policies to promote natural environments in our cities, starting in more deprived areas. © 2022Funding text 1: This project received funding from the European Union's Horizon 2020 research and innovation programme (LIFECYCLE, grant agreement No 733206; EUCAN-Connect grant agreement No 824989). ISGlobal acknowledges support from the Spanish Ministry of Science and Innovation and State Research Agency through the “Centro de Excelencia Severo Ochoa 2019-2023” Program (CEX2018-000806-S), and support from the Generalitat de Catalunya through the CERCA Program. For more information of each cohort individual funding, see Supplementary Material s, Information S2. ; Funding text 2: We would like to thanks to all the mothers, fathers, and children for their generous contribution as participants in the cohorts that are part of the LifeCycle project. For more information of each cohort individual acknowledgment, see Supplementary Materials, Information S1. This project received funding from the European Union's Horizon 2020 research and innovation programme (LIFECYCLE, grant agreement No 733206; EUCAN-Connect grant agreement No 824989). ISGlobal acknowledges support from the Spanish Ministry of Science and Innovation and State Research Agency through the “Centro de Excelencia Severo Ochoa 2019-2023” Program (CEX2018-000806-S), and support from the Generalitat de Catalunya through the CERCA Program. For more information of each cohort individual funding, see Supplementary Materials, Information S2. DAL has received support from Medtronic Ltd and Roche Diagnostics for research unrelated to this study. All the other authors declare that they have no competing interests