Genetic diversity and population structure of a rare flowering tree endemic to Appalachia, Stewartia ovata.

Stewartia ovata (cav.) Weatherby, commonly known as mountain stewartia, is an understory tree native to the southeastern United States (U.S.). This relatively rare species occurs in isolated populations in Virginia, Kentucky, Tennessee, North Carolina, South Carolina, Georgia, Alabama, and Mississippi. As a species, S. ovata has largely been overlooked, and limited information is available regarding its ecology, which presents obstacles to conservation efforts. Stewartia ovata has vibrant, large white flowers that bloom in summer with a variety of filament colors, suggesting potential horticultural traits prized by ornamental industry. However, S. ovata is relatively slow growing and, due to long seed dormancy, propagation is challenging with limited success rates. This has created a need to assess the present genetic diversity in S. ovata populations to inform potential conservation and restoration of the species. Here, we employ a genotyping-by-sequencing (GBS) approach to characterize the spatial distribution and genetic diversity of S. ovata in the southern Appalachia region of the eastern United States. A total of 4475 single nucleotide polymorphisms (SNPs) were identified across 147 individuals from 11 collection sites. Our results indicate low genetic diversity (He = 0.216), the presence of population structure (K = 2), limited differentiation (F ST = 0.039), and high gene flow (Nm = 6.16) between our subpopulations. Principal component analysis corroborated the findings of STRUCTURE, confirming the presence of two distinct S. ovata subpopulations. One subpopulation mainly contains genotypes from the Cumberland Plateau, Tennessee, while the other consists of genotypes present in the Great Smoky Mountain ranges in Tennessee, North Carolina, and portions of Nantahala, Chattahoochee-Oconee national forests in Georgia, highlighting that elevation likely plays a major role in its distribution. Our results further suggested low inbreeding coefficient (F IS = 0.070), which is expected with an outcrossing tree species. This research further provides necessary insight into extant subpopulations and has generated valuable resources needed for conservation efforts of S. ovata.

Frequency of Low Cardiac Output Syndrome Following on Pump Coronary Artery Bypass Grafting Surgery and it's Association with Degree of Pre-operative Left Ventricular Dysfunction.

Background Low cardiac output syndrome (LCOS) is a serious complication after coronary artery bypass grafting (CABG) surgery. It is associated with 10 times to 17 times increase in mortality and markedly increase morbidity. Objective To find out the frequency of Low cardiac output syndrome following on pump coronary artery bypass grafting surgery, to determine the association of Low cardiac output syndrome with degree of pre-operative left ventricular dysfunction and to compare in hospital outcomes of coronary bypass surgery with and without low cardiac output syndrome. Method This prospective, descriptive study enrolled 200 patients who underwent on pump coronary artery bypass grafting surgery using antegrade St Thomas blood cardioplegia. Pre-operatively grouped into two groups consisting Group A of 100 patients with pre-operative left ventricular ejection fraction (LVEF) ≥ 40% and group B of 100 patients with pre-operative left ventricular ejection fraction (LVEF) < 40%. Post-operatively frequency of low cardiac output syndrome was compared between the groups and in-hospital outcomes were studied. Result The mean age of the patients in the study was 53.50±7.57 years. Male to female ratio was 1.8:1. Results showed overall frequency of low cardiac output syndrome was 21.5%. The frequency of LCOS was 15 vs 28% (p - 0.038) in patients with preoperative LV EF ≥ 40% and < 40% respectively. The outcomes of coronary artery bypass grafting surgery were stroke (3.82 vs. 30.23%, p - 0.001), acute kidney injury (5.09 vs. 23.25%, p - 0.001), respiratory failure (6.36 vs. 34.88%, p - 0.001), ICU stay days (4.75 ± 1.28 vs. 7.44 ± 4.66, p - 0.018), hospital stay days (9.56 ± 2.40 vs. 15.22 ± 3.89, p - 0.001) and mortality (4.45 vs. 32.55%, p - 0.001) in patients without and with low cardiac output syndrome respectively. Conclusion The frequency of low cardiac output syndrome following coronary artery bypass surgery is 21.5%. Left ventricular dysfunction pre-operatively is associated with high frequency of low cardiac output syndrome following surgery. There is significantly poor outcome of coronary artery bypass surgery with low cardiac output syndrome in terms of stroke, respiratory failure, acute kidney injury, mortality and significant ICU stay, hospital stay in compare to patients without low cardiac output syndrome.

Impact of Adolescent's Obesity in Cardiac Function: An Association of Cardiac Structural and Metabolic Risk Factors with Physical Fitness.

Background Elderly obese results metabolic, cardiac structural and functional derangements. However, such alterations including physical fitness in early age obesity are still controversial. Objective To evaluate physical fitness, cardiac structural, functional and metabolic remodeling and their association with obesity markers in adolescents. Method This cross-sectional comparative study included 90 adolescents with median age -14(2) years were grouped into Normal weight (NW) and Overweight/Obese (OW/OB) based on the BMI percentile for age and sex. International Diabetes Federation criteria for adolescents selected for lipid profiles, fasting sugar, systolic (SBP) and diastolic blood pressure (DBP). Echocardiographic standard 2-dimensional measurements for cardiac structures, percent ejection fraction (EF%) were performed with standard procedure. Physical fitness index (PFI) was graded using the modified Harvard step test. The data compared with Mann Whitney U test and Spearman's Rank correlation test used to find association among study variables. Result Compared to normal weight adolescents, overweight/obese individuals exhibited significantly higher cardiac function parameters, including heart rate, systolic and diastolic blood pressure. Within the realm of cardio-metabolic parameters, it was observed that individuals exhibited diminished levels of high-density lipoproteins and elevated levels of low-density lipoproteins. Notably, these individuals manifested cardiac structural remodeling characterized by augmented left atrial wall and aortal base thickness, and increased left ventricular end-diastolic diameter, concomitant with a markedly decreased percentage of left ventricular ejection fraction. Cardiac structural and functional parameters revealed adverse correlation with obesity markers. Conclusion The onset of obesity in early age has been ascertained to exert profound ramifications, encompassing not solely metabolic and biochemical parameters, but also extending to the structural integrity of the cardiovascular system. These outcomes synergistically contribute to a notable attenuation in overall physical fitness.

Orsellinic acid-loaded chitosan nanoparticles in gelatin/nanohydroxyapatite scaffolds for bone formation in vitro.

AIM: Orsellinic acid (2,4-Dimethoxy-6-methylbenzoic acid) (OA) is a hydrophobic polyphenolic compound with therapeutic potential, but its impact on actuating osteogenesis remains unknown. The bioavailability of OA is hampered by its hydrophobic nature. This study aimed to fabricate nano-drug delivery system-based scaffolds for OA and test its potential for osteogenesis in vitro. MATERIALS AND METHODS: OA was loaded into chitosan nanoparticles (nCS + OA) using the ionic gelation technique at different concentrations. nCS + OA were incorporated onto the scaffolds containing gelatin (Gel) and nanohydroxyapatite (nHAp) by the lyophilization method. Biocomposite scaffolds were examined for their physicochemical and material characteristic properties. The effect of OA in the scaffolds for osteoblast differentiation was determined by alizarin red and von Kossa staining at the cellular level and by reverse transcriptase-qPCR and western blot analysis at the molecular level. KEY FINDINGS: The scaffolds showed excellent physiochemical and material characteristics and remained cyto-friendly to mouse mesenchymal stem cells (mMSCs, C3H10T1/2). The release of OA from Gel/nHAp/nCS scaffolds enhanced the differentiation of mMSCs towards osteoblasts, as observed through cellular and molecular studies. Moreover, the osteogenic potential of OA was mediated by the activation of FAK and ERK signaling pathways through integrins. SIGNIFICANCE: The inclusion of OA into Gel/nHAp/nCS biocomposite scaffolds at 80 µM concentration promoted osteoblast differentiation via cell adhesion mediated signaling, compared with that shown by Gel/nHAp/nCS alone. Overall, this study identified the potential therapeutic OA containing Gel/nHAp/nCS scaffolds, accelerating its potential for clinical application towards bone regeneration.

Testing the maturation and the radiographic visibility of the root pulp of mandibular third molars for predicting 21 years. A digital panoramic radiographic study in emerging adults of south Indian origin.

Prediction of the attainment of legal age thresholds, especially in children and young adults, is a common task in medico-legal practice. In many countries, 21 years has medico-legal importance. In the present study, we assessed and compared the accuracy of the third molar maturity index (I3M) and the stages of radiographic visibility of the root pulp (RPV) in predicting the age threshold of 21 years. A sample of 910 digital panoramic radiographs (455 males and 455 females) of adolescents and young adults aged between 16 and 30 of south Indian origin were evaluated. The authors examined the performance of different I3M cut-off values and RPV stages. I3M cut-off value of 0.02 has resulted in better discrimination with an accuracy of 76.92% and 80.44%, specificity of 48.28% and 56.16% in males and females, a sensitivity of 100%, and post-test probability of 65.9% in both sexes. The accuracy and sensitivity of RPV stage 2 were 84.76% and 84.55%, 78.17%, and 78.97% in males and females, while the specificity and post-test probability were 100% in both sexes. In conclusion, the I3M method resulted in a more significant percentage of false positives and cannot be used to state the attainment of 21 years. However, the presence of RPV stage 2 could say that the subject had already attained the age of 21 years. Further studies are warranted to address the usefulness of these methods.

Chitosan-based 3D-printed scaffolds for bone tissue engineering.

Despite the spontaneous regenerative properties of autologous bone grafts, this technique remains dilatory and restricted to fractures and injuries. Conventional grafting strategies used to treat bone tissue damage have several limitations. This highlights the need for novel approaches to overcome the persisting challenges. Tissue-like constructs that can mimic natural bone structurally and functionally represent a promising strategy. Bone tissue engineering (BTE) is an approach used to develop bioengineered bone with subtle architecture. BTE utilizes biomaterials to accommodate cells and deliver signaling molecules required for bone rejuvenation. Among the various techniques available for scaffold creation, 3D-printing technology is considered to be a superior technique as it enables the design of functional scaffolds with well-defined customizable properties. Among the biomaterials obtained from natural, synthetic, or ceramic origins, naturally derived chitosan (CS) polymers are promising candidates for fabricating reliable tissue constructs. In this review, the physicochemical-biological properties and applications of CS-based 3D-printed scaffolds and their future perspectives in BTE are summarized.

3D-poly (lactic acid) scaffolds coated with gelatin and mucic acid for bone tissue engineering.

Three-dimensional (3D) printing is a promising technology to fabricate the intricate biomimetic structure. The primary focus of this study was to develop the bioactive 3D-scaffolds to enhance bone regeneration. The 3D-poly (lactic acid) (PLA) scaffolds were extruded based on a computer-aided design (CAD) model and coated with gelatin (Gel) containing different concentrations of mucic acid (MA) and were investigated for their osteogenic potential. Coating the PLA scaffolds with Gel/MA improved their physicochemical properties, and the addition of MA did not alter these properties. The viability of mouse mesenchymal stem cells (mMSCs, C3H10T1/2) seeded onto the PLA/Gel/MA scaffolds remained unaffected both at metabolic and cell membrane integrity levels. Alkaline phosphatase and von Kossa staining indicated the promotion of osteoblast differentiation of mMSCs by MA in the PLA/Gel scaffolds. Inclusion of MA in PLA/Gel scaffolds also increased the expression of the master bone transcription factor, Runx2, and other osteoblastic differentiation marker genes in mMSCs. Thus, our results suggested that the 3D-printed PLA scaffolds coated with Gel/MA favor osteoblast differentiation and have potential applications in bone tissue engineering.

Influence of 3-aminobenzamide, an inhibitor of poly(ADP-ribose)polymerase, in the evaluation of the genotoxicity of doxorubicin, cyclophosphamide and zidovudine in female mice.

Testing new chemical entities for genotoxicity is an integral part of the preclinical drug-development process. Lowering the detection limit and enhancing the sensitivity of genotoxicity assays is required, as the standard test-battery fails to detect some carcinogens (non-genotoxic) and weak genotoxins. One of the mechanisms that affect the detection of weak genotoxins is related with the DNA-repair efficiency of the cell system used. In the present study, 3-aminobenzamide (3-AB, 30 mg/kg body-weight), a poly(ADP-ribose)polymerase inhibitor, was used to evaluate the DNA-damaging potential of zidovudine (AZT, 400 mg/kg bw), doxorubicin (DOX, 5 mg/kg bw) and cyclophosphamide (CP, 50 mg/kg bw, as a positive control) and sucrose (SUC, 3 g/kg bw, as a negative control) in Swiss female mice. The endpoints considered included micronucleus formation, DNA breakage (in peripheral blood lymphocytes, bone marrow and liver; comet assay) and chromosome aberrations, as well as immunohistochemistry of PARP-1 and phosphorylated histone H2AX (γ-H2AX). The results clearly indicate that the genotoxicity of zidovudine (AZT), doxorubicin (DOX) and cyclophosphamide (CP) was significantly increased in the combination treatments (3-AB+AZT, 3-AB+DOX, 3-AB+CP) as compared with the respective controls (treatment with AZT, DOX and CP alone). There was no increase in the genotoxicity per se after treatment with SUC, 3-AB or 3-AB+SUC, compared with the control (saline). Correlation analysis suggests that all genotoxicity parameters are well correlated with each other. The results clearly show that the genotoxicity of weak genotoxins can be enhanced and detected in the presence of 3-AB in mice. Thus, this approach can be used in the pre-clinical genotoxicity screening of weak genotoxins.

Pretreatment with valproic acid, a histone deacetylase inhibitor, enhances the sensitivity of the peripheral blood micronucleus assay in rodents.

Micronucleus (MN) assay is widely used for the determination of the genotoxic potential of new chemical entities. Improvement in the sensitivity of MN assay will be advantageous for the successful detection of marginally active genotoxins. In the past, several improvements have been made in the automated scoring of micronuclei, while very few attempts have been taken to improve the sensitivity of manual micronuclei detection. The present study aims to validate the effect of valproic acid (VPA) pretreatment on the sensitivity of peripheral blood micronucleus (PBMN) assay using cyclophosphamide (CP, 50mg/kg), methotrexate (MTX, 20mg/kg) and zidovudine (AZT, 400mg/kg) in rodents. However, to find out the optimum VPA pretreatment time as well as to detect the effect of species and age difference, separate experiments were conducted on young Swiss albino mice (24-28 days) and Sprague-Dawley rats (21-24 days), in which significant increase in MN induction was observed with 3-day VPA pretreatment in both the species. Based on these results, studies on adult mice were conducted with 3-day VPA pretreatment along with CP or MTX or AZT. The results of the present study clearly demonstrate that the 3-day VPA pretreatment significantly enhances the sensitivity of PBMN assay in peripheral blood (PB) in adult mice. After validation with other standard genotoxins as well as other HDAC (histone deacetylase) inhibitors, this model may be useful for the detection of marginally active DNA damaging agents.