Primary central nervous system neuroblastoma mimicking a meningioma: A case report.

ABSTRACT: Neuroblastomas are the most common extracranial solid tumor in the pediatric age group (~8%-10% of childhood neoplasms). Most cases of intracranial neuroblastomas occur due to metastasis from some primary extracranial sites and are known as secondary neuroblastomas. However, the occurrence of primary central nervous system neuroblastomas (PCN-NB) is very rare, and only a few cases and case series have been reported in the literature. PCN-NB is mainly an intra-axial pathology, and extra-axial involvement is mainly due to metastasis from some extracranial primary site with involvement of the skull bone. Herein we report a case of a 23-year-old female having a large extra-axial space-occupying lesion in the right frontal region that was mimicking a meningioma, and surprisingly the histopathology was suggestive of a supratentorial neuroblastoma. A right frontal craniotomy was made, and Simpson's grade 1 excision of the tumor was done. The excised tissue was sent for histopathological examination. PCN-NB located extra-axially are extremely rare to occur. Due to inconsistent radiological imaging, it becomes very difficult to diagnose these tumors preoperatively, and these should be kept in mind as one of the differential diagnoses of extra-axial intracranial space-occupying lesions. Histopathological examination is crucial in diagnosing the intracranial neuroblastomas.

Comparing the Effectiveness of Traditional Periodontal Surgery Versus Non-Surgical Therapy: A Randomized Controlled Trial.

Background: Periodontal disease, characterized by inflammation and infection of the supporting structures of teeth, poses a significant oral health challenge. Traditional periodontal surgery and non-surgical therapy, such as scaling and root planing, are established treatment approaches for addressing periodontal disease. Materials and Methods: The study enrolled 120 adult patients diagnosed with moderate to severe periodontal disease. Participants were randomly allocated to one of two groups: the traditional surgery group (TSG) or the non-surgical therapy group (NSTG). In the TSG, patients underwent traditional periodontal surgery, which included flap surgery and grafts when deemed necessary. The surgical procedures were performed by experienced periodontal surgeons. In contrast, the NSTG received non-surgical therapy in the form of scaling and root planing administered by trained dental hygienists. Outcome measures encompassed clinical parameters and patient-centered outcomes. Periodontal pocket depth and clinical attachment level, both measured in millimeters, were assessed at baseline, 3 months, and 6 months. Patient-reported outcomes, including pain, discomfort, and satisfaction, were collected through standardized questionnaires at each follow-up visit. Results: Patients in the TSG experienced a notable reduction in pocket depth from a baseline of 6.8 mm to 3.7 mm at the 6-month mark, resulting in a change of -3.1 mm. Conversely, the NSTG exhibited a reduction from 6.7 mm to 4.0 mm, with a change of -2.7 mm. In the TSG, the baseline attachment level of 7.2 mm decreased to 5.1 mm at 6 months, indicating a change of -2.1 mm. In the NSTG, the attachment level decreased from 7.1 mm to 5.5 mm, resulting in a change of -1.6 mm. Patients in the TSG reported an average pain score of 3.6 on a 1-10 scale, discomfort of 4.2, and satisfaction of 7.8. In contrast, patients in the NSTG reported lower pain (2.1) and discomfort (2.9) scores but similar satisfaction levels (8.4). Conclusion: In this randomized controlled trial (RCT), both traditional periodontal surgery and non-surgical therapy demonstrated improvements in clinical parameters and patient-reported outcomes. Traditional surgery resulted in greater reductions in periodontal pocket depth and clinical attachment loss at the 6-month follow-up.

Optimization of virtual water flows in agriculture by changing cropping patterns using an integrated approach.

Utilizing available water resources efficiently is crucial to address both our present and future requirements and plays a vital role in safeguarding food security. This current investigation deals with assessment and optimizing water footprint (WF) and virtual water flow (VWF) for primary crops in Banas River Basin (BRB) using AquaCrop model with local datasets and district-level estimates. VWF in the basins were estimated by multiplying the WF of crops with the amount exported/imported, which is determined based on the difference between production and consumption in the basin. The possibility of changing the cropping patterns was evaluated for the potential reduction of the blue WF. Annual WF from primary crops in the basin amounts to 19,255 MCM/yr (70 % green, 21 % blue and 10 % grey WF, respectively). Banas basin is a net exporter of agriculture commodities with nearly 7391 MCM/yr of water flowing out of the basin due to agricultural exports of which approximately 265 MCM/yr is virtual blue water outflow. Crops having low economic water productivity of blue water are being grown in vast areas resulting in a high blue WF. The optimizing the cropping pattern can result in a 5-42 % lower blue water footprint with 11-39 % higher economic output under different scenarios with and without considering the consumption needs. Changing the cropping pattern and making trade plan to optimize the crop import/exports can be viable option for tackling the blue water scarcity issues in the basin. WF can be managed sustainably by improving water resource allocation for better economic, social, and environmental productivity and going for less aggressive agricultural production.

Rete middle cerebral artery presenting with a ruptured aneurysm.

The developmental anomaly of the middle cerebral artery (MCA) is a rare occurrence. Rete MCA, also known as "unfused," "twig-like," and aplastic MCA, is an even rarer anomaly. These immature rete vessels are prone to flow-related aneurysms which rupture themselves presenting with intraparenchymal hematoma. We here with present a case of rete MCA with a ruptured aneurysm and discuss its pathophysiology and management.

Evaluation of the Impact of Chlorhexidine Mouth Rinse on the Bond Strength of Polycarbonate Orthodontic Brackets: A Case-Control Study.

BACKGROUND: Shear bond analysis is the procedure used most frequently to gauge the tensile strength of adhesives incorporated in orthodontic treatments. In shear tensile strength analysis, pressure is placed as close as feasible to the interface between the orthodontic bracket and the surface of the tooth, parallel to the long axis of the tooth. Although numerous research on extracted teeth of human and bovine teeth have been conducted, there may still be variables such as pH, humidity, temperature, and others that could affect how these materials behave in the mouth cavity. The impact of chlorhexidine (CHX) on the binding capacity for non-metallic orthodontic brackets in vivo is not well understood. OBJECTIVE: The goal of the current study is to determine how mouth rinses containing 0.12% CHX affect the adhesive strength of polycarbonate orthodontic brackets. METHODS AND MATERIALS: Thirty-four patients were part of the test category, and they were instructed to wash their oral cavity for approximately 30 seconds using 20 ml of 0.12% CHX gluconate (Septodent). Thirty-four patients made up the control category and were instructed to wash their oral cavity for 30 seconds with a placebo mouthwash of a similar hue (20 ml). Both types of mouthwash were administered to the participants by an administrator who was not specifically involved in the trial and were kept in 120 ml labeled plastic bottles. The study participants were also kept unaware of the type of mouthwash. For the mouthwash utilized by study participants, a double-blinding technique was applied. RESULTS: Thirty-four patients were evaluated in the test category. Since the orthodontic bracket broke in two patients, therefore, 32 patients were evaluated in the control category. The mean value of the strength of the shear bond in the experimental category was 15.32 megapascal (Mpa). The SD value was 2.51. The mean value of the strength of the shear bond in the control subgroup was 15.63. On statistical analysis, the t-value was 0.47. The p-value was 0.671. The difference in findings of the strength of the shear bond was statistically non-significant. CONCLUSION: The results of this investigation allow us to draw the conclusion that the shear bond properties of polycarbonate orthodontic brackets are unaffected when treated with 0.12% CHX preceding the binding. The clinically meaningful adhesion strength was likewise attained by the polycarbonate orthodontic brackets.

Effect of novel Matrix Rhythm Therapy (MaRhyThe®) on neuropathic pain and maximum plantar pressure distribution among type 2 diabetes mellitus patients with peripheral neuropathy.

Background: There is a need for a non-pharmacological approach to reduce pain and plantar pressure in diabetic peripheral neuropathy (DPN). Matrix Rhythm Therapy (MaRhyThe®) is a therapeutic modality that works on the principle of physiologic rhythmic oscillations of the body cells. This study aimed to evaluate the effect of MaRhyThe® on neuropathic pain and maximum plantar pressure distribution among type 2 diabetes mellitus patients with peripheral neuropathy. Materials and methods: A total of 33 participants with DPN were recruited for the study based on inclusion criteria. Maximum plantar pressure was recorded using Win-Track 11K005, and the pain score was obtained using a visual analogue scale. Ten sessions of MaRhyThe® were given to all the participants. Outcome measures were evaluated at the baseline and after 10th session. Paired t-test was performed to analyze the changes in outcome measures. Results: Participants of DPN were recruited with the average age of 64 ± 9 years, and an average duration of diabetes was 14 ± 9 years were included. Results of the present study found significant improvement in neuropathic pain and plantar pressure in post intervention assessment. (p < 0.05). Conclusion: In the present study, we found that MaRhyThe® is effective in reducing neuropathic pain and maximum plantar pressure in type 2 diabetes mellitus with peripheral neuropathy.

Enhanced Drug Uptake on Application of Electroporation in a Single-Cell Model.

Electroporation method is a useful tool for delivering drugs into various diseased tissues in the human body. As a result of an applied electric field, drug particles enter the intracellular compartment through the temporarily permeabilized cell membrane. Consequently, electroporation method allows better penetration of the drug into the diseased tissue and improves treatment clinically. In this study, a more generalized model of drug transport in a single cell is proposed. The model is able to capture non-homogeneous drug transport in the cell due to non-uniform cell membrane permeabilization. Several numerical experiments are conducted to understand the effects of electric field and drug permeability on drug uptake into the cell. Through investigation, the appropriate electric field and drug permeability are identified, which lead to sufficient drug uptake into the cell. This model can be used by experimentalists to get information prior to conduct any experiment, and it may help reduce the number of actual experiments that might be conducted otherwise.

Impact of atmospheric anthropogenic nitrogen on new production in the northern Indian Ocean: constrained based on satellite aerosol optical depth and particulate nitrogen levels.

Aerosols are one of the significant external sources of soluble reactive nitrogen to the surface ocean and their deposition affects the primary productivity. Owing to rapid industrialization over South and Southeast Asia, an increasing trend in atmospheric pollutants was observed over the northern Indian Ocean (NIO). To assess the contribution of the aeolian supply of inorganic nitrogen to the NIO, the available compositional data of marine aerosols collected over this basin between 2001 and 2020 were compiled. Based on the observed relationship of mass load, and particulate nitrate and ammonium concentrations with the corresponding satellite-derived anthropogenic aerosol optical depth (AAOD), the temporal, spatial, and long-term variabilities were derived for the past two decades. In particular, high aerosol mass load, nitrate and ammonium levels were observed in the coastal aerosols of peninsular India during fall and winter and they were low in summer. The atmospheric input of inorganic nitrogen to the Arabian Sea is higher (AS; 1.7 TgN per year) compared to that of the Bay of Bengal (BoB; 0.9 TgN per year) and accounts for ∼30% of the total external sources of nitrogen to the NIO. The new production, supported by external sources of nitrogen, contributes to ∼23 and 53% of export production to the oxygen minimum zone (OMZ) in the AS and BoB respectively. A significant rate of increase in the aerosol mass load (0.05-1.67 µg per m3 per year), and nitrate (0.003-0.04 µg per m3 per year) and ammonium (0.006-0.11 µg per m3 per year) concentrations was observed between 2001 and 2020, likely because of the increased emission of anthropogenic pollutants over South and Southeast Asia and their subsequent long-range atmospheric transport to the NIO. Overall, these results suggest that an enhanced contribution of atmospheric nitrogen may potentially increase (1) the N/P ratio of the surface ocean that impacts phytoplankton composition, (2) export production to the OMZ leads to intensification, and (3) sequestration of atmospheric CO2. A decrease in primary production due to global warming is reported due to a decrease in vertical nutrient supply; however, the increase in atmospheric deposition of nutrients may compensate for this. Therefore, ocean models must be coupled with atmospheric models to better constrain the oceanic response to climate change in the NIO.

A Study on Psychosomatic Problems Related to the Problematic Internet Use among Adolescents at Selected Schools of Aspur Block, Dungarpur, Rajasthan.

Adolescents' scholastic and social life has become increasingly reliant on the internet and mobile technology in recent years. Problematic Internet Use (PIU) is a growing problem in Indian adolescents. However, in many cases, this use has become obsessive, causing them to neglect other elements of their lives. Adolescents account for over 35% of internet users in India. The purpose of this study was to evaluate the psychosomatic problems related to internet overuse among school going adolescent students. This cross-sectional survey was conducted among 348 students in selected schools of Aspur block in Dungarpur-district, Rajasthan, India in the month of February 2016. Problematic internet use (PIU) was assessed by Young's twenty question internet addiction test. The Depression, Anxiety, Stress Scale (DASS-42) and self structured questionnaire check list was used to measure psychosomatic problems among adolescents. Approximately 5.17% adolescents showed Problematic internet use (PIU). Adolescents with PIU were associated with age between 14-16 year, males,10th class of study, using internet since more than 3 years, being at home, mobile as a source of internet use, purpose of internet use with online gaming. Compared with normal internet users, there were significant correlation between Problematic Internet Use and Somatic Complaints r=0.3660, p<0.05, Depression r=0.3982, p<0.05. Anxiety r=0.2512, p<0.05 and Stress r=0.2886, p<0.05. Problematic internet use (PIU) is an increasing problem among teenagers and it has been linked to psychosomatic issues. Timely Effective measures are needed to prevent the spread of this problem.

Decadal variations in natural and anthropogenic aerosol optical depth over the Bay of Bengal: the influence of pollutants from Indo-GangeticPlain.

Perennial increase in atmospheric pollution over the Bay of Bengal (BoB) and South China Sea is reported due to increase in human population and industrial activity in South and Southeast Asia. Based on total aerosol optical depth (AOD) derived from MODIS (moderate resolution imaging resolution imaging spectroradiometer), natural and anthropogenic fractions were derived. The seasonality and spatial variability in rate of increase in total, natural, and anthropogenic AOD fractions were examined over the BoB using data collected between 2001 and 2019. Both total and anthropogenic AOD displayed statistically significant rate of increase in the northwest BoB (NWB) and western coastal BoB (WCB) regions during 2001 to 2019 whereas the long-term changes are insignificant in the other regions of BoB. Significant increase in AOD in the NWB and WCB regions is mainly contributed by dominant outflow of anthropogenic emissions from Indo-Gangetic Plain (IGP) area of Indian subcontinent. The magnitude of AOD decreased by half from northern BoB to equatorial region due to increase in distance from the source region. The contribution of anthropogenic AOD was >70% to total AOD with higher contribution during winter and lower during summer. The rate of increase in both total and anthropogenic AOD was close to 0.104 and 0.099 per decade in the NWB and 0.069 and 0.059 per decade in the WCB region between 2001 and 2019. The rate of increase in total and anthropogenic AOD decreased from 2001-2009 (0.164 and 0.115 per decade respectively) to 2010-2019 (0.068 and 0.076 per decade respectively) in the NWB region. Significant increase in anthropogenic AOD by 50 and 30% was observed during El Niño and La Niña periods respectively than normal year in both northwest BoB (NWB) and western coastal (WCB) regions due to change in strength and direction of winds. Although some fraction of anthropogenic AOD is found over the entire BoB, significant rate of increase in anthropogenic AOD is found only about 23% of the area of BoB than hitherto reported as entire BoB. The impact of atmospheric deposition of anthropogenic aerosols on biogeochemical processes, such as primary production and ocean acidification, needs further evaluation.

Supramolecular associations between atypical oxidative phosphorylation complexes of Euglena gracilis.

In vivo associations of respiratory complexes forming higher supramolecular structures are generally accepted nowadays. Supercomplexes (SC) built by complexes I, III and IV and the so-called respirasome (I/III2/IV) have been described in mitochondria from several model organisms (yeasts, mammals and green plants), but information is scarce in other lineages. Here we studied the supramolecular associations between the complexes I, III, IV and V from the secondary photosynthetic flagellate Euglena gracilis with an approach that involves the extraction with several mild detergents followed by native electrophoresis. Despite the presence of atypical subunit composition and additional structural domains described in Euglena complexes I, IV and V, canonical associations into III2/IV, III2/IV2 SCs and I/III2/IV respirasome were observed together with two oligomeric forms of the ATP synthase (V2 and V4). Among them, III2/IV SC could be observed by electron microscopy. The respirasome was further purified by two-step liquid chromatography and showed in-vitro oxygen consumption independent of the addition of external cytochrome c.

Toward the Origin of Magnetic Field-Dependent Storage Properties: A Case Study on the Supercapacitive Performance of FeCo2O4 Nanofibers.

Despite the many reports in the literature on the magnetic field-dependent energy storage properties of metal oxides, the origin of magnetic field-dependent supercapacitive properties is still not clear. This is because electrode's properties such as physical (electrical and magnetic properties), structural and microstructural (surface area, pore size, and their distribution), and electrolyte's properties (ionic diffusion, ionic conductivity, cation size, etc.) are very crucial for investigating the effect of a magnetic field on the energy storage properties of metal oxides. In this article, the effect of a magnetic field on some of the abovementioned properties and thereby on the supercapacitive properties of FeCo2O4 (FCO) nanofibers is thoroughly investigated. The local magnetic environment of the magnetized electrode (magnetic gradient force, susceptibility, etc.) is proposed to be crucial for tuning the storage properties of the electrode material. Magnetic field-mediated resistive properties of the electrode material and thereby the induced magnetic gradient force at the electrode surface seem to be helpful in lowering the Nernst layer thickness and improving the electrode/electrolyte interface for a smoother ionic exchange resulting in 56% increment in the capacitance values of FCO nanofibers. A series of electrochemical experiments (cyclic voltammetry and galvanostatic charge-discharge) and magnetic property evaluation of bare and cycled electrodes are carried out, and the proposed mechanism/hypothesis is validated by studying the ex situ magnetic properties and the results are discussed in detail.

Urine Extracellular Vesicle GATA2 mRNA Discriminates Biopsy Result in Men with Suspicion of Prostate Cancer.

PURPOSE: Prostate specific antigen has limited performance in detecting prostate cancer. The transcription factor GATA2 is expressed in aggressive prostate cancer. We analyzed the predictive value of urine extracellular vesicle GATA2 mRNA alone and in combination with a multigene panel to improve detection of prostate cancer and high risk disease. MATERIALS AND METHODS: GATA2 mRNA was analyzed in matched extracellular vesicles isolated from urines before and after prostatectomy (16) and paired urine and tissue prostatectomy samples (19). Extracellular vesicle GATA2 mRNA performance to distinguish prostate cancer and high grade disease was tested in training (52) and validation (165) cohorts. The predictive value of a multigene score including GATA2, PCA3 and TMPRSS2-ERG (GAPT-E) was tested in both cohorts. RESULTS: Confirming its prostate origin, urine extracellular vesicle GATA2 mRNA levels decreased significantly after prostatectomy and correlated with prostate cancer tissue GATA2 mRNA levels. In the training and validation cohort GATA2 discriminated prostate cancer (AUC 0.74 and 0.66) and high grade disease (AUC 0.78 and 0.65), respectively. Notably, the GAPT-E score improved discrimination of prostate cancer (AUC 0.84 and 0.72) and high grade cancer (AUC 0.85 and 0.71) in both cohorts when compared with each biomarker alone and PT-E (PCA3 and TMPRSS2-ERG). A GAPT-E score for high grade prostate cancer would avoid 92.1% of unnecessary prostate biopsies, compared to 61.9% when a PT-E score is used. CONCLUSIONS: Urine extracellular vesicle GATA2 mRNA analysis improves the detection of high risk prostate cancer and may reduce the number of unnecessary biopsies.

Pancytopenia without Hepatosplenomegaly: A Rare Manifestation of Extrapulmonary Tuberculosis in an Adolescent Boy.

Extrapulmonary tuberculosis (TB) is a well-recognized cause of pyrexia of unknown origin. However, clinical presentation of TB in children with isolated hematological abnormalities is extremely rare. Anemia, usually normocytic, normochromic, leukopenia, leukocytosis, thrombocytopenia, thrombocytosis, and monocytosis are more common complications of TB rather than pancytopenia. Only anecdotal case reports and small case series are available in this regard. We are reporting an 18-year-old boy who presented with on and off low-grade fever for 3 months and anorexia and progressive pallor for 1 month. After extensive workup, pancytopenia remained unexplained. Bone marrow (BM) examination revealed caseating granulomas, along with Mantoux positivity and contact with sputum-positive pulmonary TB. He responded favorably to antitubercular therapy (ATT) within 2 months. This report alerts clinicians to be vigilant regarding the rare possibility of BM TB while investigating unexplained pancytopenia, as it is completely reversible with ATT.

Spatial and temporal variability in concentration and characteristics of aerosols at Visakhapatnam (east) and Goa (west) coasts of India.

Knowledge on the variability in quantity and compositions of various size groups of aerosols is important to understand their sources and their role in biogeochemical and climate processes. Here, we studied total suspended particles (TSP), PM10 and PM2.5 for their quantitative and water soluble compositional (F-, Cl-, SO42-, NO3-, NH4+, Na+, K+, Ca2+, and Mg2+) distributions, and to understand their nature and potential sources at Goa and Visakhapatnam on the west and east coasts, respectively, of India. While the mean concentrations of TSP were found to be 117 ± 44 and 85 ± 51 µg/m3 its maximal levels occurred in spring intermonsoon (SIM; 141 ± 52) and winter monsoon (WM; 155 ± 145 µg/m3) seasons at Goa and Visakhapatnam, respectively. PM10 and PM2.5 exhibited higher ranges at Visakhapatnam than Goa. The increase in PM2.5 abundance from WM to SIM at Visakhapatnam seems to occur in coincidence with decrease in TSP favored by topography and ambient meteorological conditions. Locally released and seasonally transported (from land and sea) constituents contributed to the observed variability in aerosol compositions. Sulphate dominated the aerosol composition at both Goa (57-64%) and Visakhapatnam (43-55%) followed by NO3- (5-16% and 6-18%, respectively) where the former component was higher in PM10 and PM2.5. The NO3- was more in TSP. Relations between SO42- and NH4+ suggested possible presence of NH4HSO4. Examination of ionic ratios and balance suggested near neutrality in PM10 and PM2.5 while TSP was acidic at the both locations. Notable relations between Ca2+ and NO3-, particularly in PM10 at Goa, indicated their release from mining related activities.

Atomic resolution cryo-EM structure of a native-like CENP-A nucleosome aided by an antibody fragment.

Genomic DNA in eukaryotes is organized into chromatin through association with core histones to form nucleosomes, each distinguished by their DNA sequences and histone variants. Here, we used a single-chain antibody fragment (scFv) derived from the anti-nucleosome antibody mAb PL2-6 to stabilize human CENP-A nucleosome containing a native α-satellite DNA and solved its structure by the cryo-electron microscopy (cryo-EM) to 2.6 Å resolution. In comparison, the corresponding cryo-EM structure of the free CENP-A nucleosome could only reach 3.4 Å resolution. We find that scFv binds to a conserved acidic patch on the histone H2A-H2B dimer without perturbing the nucleosome structure. Our results provide an atomic resolution cryo-EM structure of a nucleosome and insight into the structure and function of the CENP-A nucleosome. The scFv approach is applicable to the structural determination of other native-like nucleosomes with distinct DNA sequences.

Co-evolution of spliceosomal disassembly interologs: crowning J-protein component with moonlighting RNA-binding activity.

Spliceosome disassembly is catalyzed by the NineTeen-related (NTR) complex, which is constituted by several proteins, including Cwc23, Ntr1, and Ppr43. Cwc23 is an essential J-protein in Saccharomyces cerevisiae that recruits Ntr1, an NTC-related G-patch protein, to the spliceosome. Ntr1 interacts with Prp43, a DExD/H box RNA helicase protein, which facilitates the disassembly of spliceosomal intermediates. The interaction between Ntr1 and Prp43 is conserved and crucial for the disassembly process. However, the J-protein component of this complex is not studied in other eukaryotes. In silico analysis supported by results of yeast complementation and two-hybrid studies suggests that while Prp43 is highly conserved, both Ntr1 and Cwc23 are co-evolving components of the disassembly triad. The J-domain of Cwc23, which is otherwise dispensable for its function, is highly conserved, whereas the functionally critical C-terminus has significantly diverged in Cwc23 orthologs. Some eukaryotic orthologs of Cwc23 contain a distinct RNA recognition motif at their C-terminus and are able to bind RNA in vitro. Based on the results presented in this study, we propose that RNA-binding activity in some eukaryotic orthologs of Cwc23 might provide additional functional diversity or robustness to the J-protein/Hsp70 machine in spliceosomal remodelling processes.

An alkali tolerant α-l-rhamnosidase from Fusarium moniliforme MTCC-2088 used in de-rhamnosylation of natural glycosides.

Analkali tolerant α-l-rhamnosidase has been purified to homogeneity from the culture filtrate of a new fungal strain, Fusarium moniliforme MTCC-2088, using concentration by ultrafiltration and cation exchange chromatography on CM cellulose column. The molecular mass of the purified enzyme has been found to be 36.0 kDa using SDS-PAGE analysis. The Km value using p-nitrophenyl-α-l-rhamnopyranoside as the variable substrate in 0.2 M sodium phosphate buffer pH10.5 at50 °C was 0.50 mM. The catalytic rate constant was15.6 s-1giving the values of kcat/Km is 3.12 × 104M-1 s-1. The pH and temperature optima of the enzyme were 10.5 and 50 °C, respectively. The purified enzyme had better stability at 10 °C in basic pH medium. The enzyme derhamnosylated natural glycosides like naringin to prunin, rutin to isoquercitrin and hesperidin to hesperetin glucoside. The purified α-l-rhamnosidase has potential for enhancement of wine aroma.

Revisit of Reconstituted 30-nm Nucleosome Arrays Reveals an Ensemble of Dynamic Structures.

It has long been suggested that chromatin may form a fiber with a diameter of ~30 nm that suppresses transcription. Despite nearly four decades of study, the structural nature of the 30-nm chromatin fiber and conclusive evidence of its existence in vivo remain elusive. The key support for the existence of specific 30-nm chromatin fiber structures is based on the determination of the structures of reconstituted nucleosome arrays using X-ray crystallography and single-particle cryo-electron microscopy coupled with glutaraldehyde chemical cross-linking. Here we report the characterization of these nucleosome arrays in solution using analytical ultracentrifugation, NMR, and small-angle X-ray scattering. We found that the physical properties of these nucleosome arrays in solution are not consistent with formation of just a few discrete structures of nucleosome arrays. In addition, we obtained a crystal of the nucleosome in complex with the globular domain of linker histone H5 that shows a new form of nucleosome packing and suggests a plausible alternative compact conformation for nucleosome arrays. Taken together, our results challenge the key evidence for the existence of a limited number of structures of reconstituted nucleosome arrays in solution by revealing that the reconstituted nucleosome arrays are actually best described as an ensemble of various conformations with a zigzagged arrangement of nucleosomes. Our finding has implications for understanding the structure and function of chromatin in vivo.